WorldWideScience

Sample records for maximum average output

  1. Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers

    OpenAIRE

    Richard Billich; Jakub Štvrtňa; Karel Jelen

    2015-01-01

    Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers In today’s world of strength training there are many myths surrounding effective exercising with the least possible negative effect on one’s health. In this experiment we focus on the finding of a relationship between maximum output, used load and the velocity with which the exercise is performed. The main objective is to find the optimal speed of the exercise motion which would allow us to reach the ma...

  2. FEL system with homogeneous average output

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David R.; Legg, Robert; Whitney, R. Roy; Neil, George; Powers, Thomas Joseph

    2018-01-16

    A method of varying the output of a free electron laser (FEL) on very short time scales to produce a slightly broader, but smooth, time-averaged wavelength spectrum. The method includes injecting into an accelerator a sequence of bunch trains at phase offsets from crest. Accelerating the particles to full energy to result in distinct and independently controlled, by the choice of phase offset, phase-energy correlations or chirps on each bunch train. The earlier trains will be more strongly chirped, the later trains less chirped. For an energy recovered linac (ERL), the beam may be recirculated using a transport system with linear and nonlinear momentum compactions M.sub.56, which are selected to compress all three bunch trains at the FEL with higher order terms managed.

  3. Estimation of the Maximum Output Power of Double-Clad Photonic Crystal Fiber Laser

    International Nuclear Information System (INIS)

    Chen Yue-E; Wang Yong; Qu Xi-Long

    2012-01-01

    Compared with traditional optical fiber lasers, double-clad photonic crystal fiber (PCF) lasers have larger surface-area-to-volume ratios. With an increase of output power, thermal effects may severely restrict output power and deteriorate beam quality of fiber lasers. We utilize the heat-conduction equations to estimate the maximum output power of a double-clad PCF laser under natural-convection, air-cooling, and water-cooling conditions in terms of a certain surface-volume heat ratio of the PCF. The thermal effects hence define an upper power limit of double-clad PCF lasers when scaling output power. (fundamental areas of phenomenology(including applications))

  4. Theoretical and experimental investigations of the limits to the maximum output power of laser diodes

    International Nuclear Information System (INIS)

    Wenzel, H; Crump, P; Pietrzak, A; Wang, X; Erbert, G; Traenkle, G

    2010-01-01

    The factors that limit both the continuous wave (CW) and the pulsed output power of broad-area laser diodes driven at very high currents are investigated theoretically and experimentally. The decrease in the gain due to self-heating under CW operation and spectral holeburning under pulsed operation, as well as heterobarrier carrier leakage and longitudinal spatial holeburning, are the dominant mechanisms limiting the maximum achievable output power.

  5. Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers

    Directory of Open Access Journals (Sweden)

    Richard Billich

    2015-03-01

    Full Text Available Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers In today’s world of strength training there are many myths surrounding effective exercising with the least possible negative effect on one’s health. In this experiment we focus on the finding of a relationship between maximum output, used load and the velocity with which the exercise is performed. The main objective is to find the optimal speed of the exercise motion which would allow us to reach the maximum mechanic muscle output during a bench press exercise. This information could be beneficial to sporting coaches and recreational sportsmen alike in helping them improve the effectiveness of fast strength training. Fifteen football players of the FK Třinec football club participated in the experiment. The measurements were made with the use of 3D cinematic and dynamic analysis, both experimental methods. The research subjects participated in a strength test, in which the mechanic muscle output of 0, 10, 30, 50, 70, 90% and one repetition maximum (1RM was measured. The acquired result values and other required data were modified using Qualisys Track Manager and Visual 3D software (C-motion, Rockville, MD, USA. During the bench press exercise the maximum mechanic muscle output of the set of research subjects was reached at 75% of maximum exercise motion velocity. Optimální rychlost pohybu pro dosažení maxima výstupního výkonu – bench press u trénovaných fotbalistů Dnešní svět silového tréninku přináší řadu mýtů o tom, jak cvičit efektivně a zároveň s co nejmenším negativním vlivem na zdraví člověka. V tomto experimentu se zabýváme nalezením vztahu mezi maximálním výkonem, použitou zátěží a rychlostí. Hlavním úkolem je nalezení optimální rychlosti pohybu pro dosažení maximálního mechanického svalového výkonu při cvičení bench press, což pomůže nejenom trenérům, ale i rekreačním sportovc

  6. Potential role of motion for enhancing maximum output energy of triboelectric nanogenerator

    Science.gov (United States)

    Byun, Kyung-Eun; Lee, Min-Hyun; Cho, Yeonchoo; Nam, Seung-Geol; Shin, Hyeon-Jin; Park, Seongjun

    2017-07-01

    Although triboelectric nanogenerator (TENG) has been explored as one of the possible candidates for the auxiliary power source of portable and wearable devices, the output energy of a TENG is still insufficient to charge the devices with daily motion. Moreover, the fundamental aspects of the maximum possible energy of a TENG related with human motion are not understood systematically. Here, we confirmed the possibility of charging commercialized portable and wearable devices such as smart phones and smart watches by utilizing the mechanical energy generated by human motion. We confirmed by theoretical extraction that the maximum possible energy is related with specific form factors of a TENG. Furthermore, we experimentally demonstrated the effect of human motion in an aspect of the kinetic energy and impulse using varying velocity and elasticity, and clarified how to improve the maximum possible energy of a TENG. This study gives insight into design of a TENG to obtain a large amount of energy in a limited space.

  7. Potential role of motion for enhancing maximum output energy of triboelectric nanogenerator

    Directory of Open Access Journals (Sweden)

    Kyung-Eun Byun

    2017-07-01

    Full Text Available Although triboelectric nanogenerator (TENG has been explored as one of the possible candidates for the auxiliary power source of portable and wearable devices, the output energy of a TENG is still insufficient to charge the devices with daily motion. Moreover, the fundamental aspects of the maximum possible energy of a TENG related with human motion are not understood systematically. Here, we confirmed the possibility of charging commercialized portable and wearable devices such as smart phones and smart watches by utilizing the mechanical energy generated by human motion. We confirmed by theoretical extraction that the maximum possible energy is related with specific form factors of a TENG. Furthermore, we experimentally demonstrated the effect of human motion in an aspect of the kinetic energy and impulse using varying velocity and elasticity, and clarified how to improve the maximum possible energy of a TENG. This study gives insight into design of a TENG to obtain a large amount of energy in a limited space.

  8. An implementation of the maximum-caliber principle by replica-averaged time-resolved restrained simulations.

    Science.gov (United States)

    Capelli, Riccardo; Tiana, Guido; Camilloni, Carlo

    2018-05-14

    Inferential methods can be used to integrate experimental informations and molecular simulations. The maximum entropy principle provides a framework for using equilibrium experimental data, and it has been shown that replica-averaged simulations, restrained using a static potential, are a practical and powerful implementation of such a principle. Here we show that replica-averaged simulations restrained using a time-dependent potential are equivalent to the principle of maximum caliber, the dynamic version of the principle of maximum entropy, and thus may allow us to integrate time-resolved data in molecular dynamics simulations. We provide an analytical proof of the equivalence as well as a computational validation making use of simple models and synthetic data. Some limitations and possible solutions are also discussed.

  9. Maximum power output and load matching of a phosphoric acid fuel cell-thermoelectric generator hybrid system

    Science.gov (United States)

    Chen, Xiaohang; Wang, Yuan; Cai, Ling; Zhou, Yinghui

    2015-10-01

    Based on the current models of phosphoric acid fuel cells (PAFCs) and thermoelectric generators (TGs), a new hybrid system is proposed, in which the effects of multi-irreversibilities resulting from the activation, concentration, and ohmic overpotentials in the PAFC, Joule heat and heat leak in the TG, finite-rate heat transfer between the TG and the heat reservoirs, and heat leak from the PAFC to the environment are taken into account. Expressions for the power output and efficiency of the PAFC, TG, and hybrid system are analytically derived and directly used to discuss the performance characteristics of the hybrid system. The optimal relationship between the electric currents in the PAFC and TG is obtained. The maximum power output is numerically calculated. It is found that the maximum power output density of the hybrid system will increase about 150 Wm-2, compared with that of a single PAFC. The problem how to optimally match the load resistances of two subsystems is discussed. Some significant results for practical hybrid systems are obtained.

  10. Stochastic modelling of the monthly average maximum and minimum temperature patterns in India 1981-2015

    Science.gov (United States)

    Narasimha Murthy, K. V.; Saravana, R.; Vijaya Kumar, K.

    2018-04-01

    The paper investigates the stochastic modelling and forecasting of monthly average maximum and minimum temperature patterns through suitable seasonal auto regressive integrated moving average (SARIMA) model for the period 1981-2015 in India. The variations and distributions of monthly maximum and minimum temperatures are analyzed through Box plots and cumulative distribution functions. The time series plot indicates that the maximum temperature series contain sharp peaks in almost all the years, while it is not true for the minimum temperature series, so both the series are modelled separately. The possible SARIMA model has been chosen based on observing autocorrelation function (ACF), partial autocorrelation function (PACF), and inverse autocorrelation function (IACF) of the logarithmic transformed temperature series. The SARIMA (1, 0, 0) × (0, 1, 1)12 model is selected for monthly average maximum and minimum temperature series based on minimum Bayesian information criteria. The model parameters are obtained using maximum-likelihood method with the help of standard error of residuals. The adequacy of the selected model is determined using correlation diagnostic checking through ACF, PACF, IACF, and p values of Ljung-Box test statistic of residuals and using normal diagnostic checking through the kernel and normal density curves of histogram and Q-Q plot. Finally, the forecasting of monthly maximum and minimum temperature patterns of India for the next 3 years has been noticed with the help of selected model.

  11. Determinants of mobile phone output power in a multinational study: implications for exposure assessment

    DEFF Research Database (Denmark)

    Vrijheid, M; Madsen, Stine Mann; di Vecchia, Paolo

    2009-01-01

    OBJECTIVES: The output power of a mobile phone is directly related to its radiofrequency (RF) electromagnetic field strength, and may theoretically vary substantially in different networks and phone use circumstances due to power control technologies. To improve indices of RF exposure for epidemi......OBJECTIVES: The output power of a mobile phone is directly related to its radiofrequency (RF) electromagnetic field strength, and may theoretically vary substantially in different networks and phone use circumstances due to power control technologies. To improve indices of RF exposure...... on the average output power and the percentage call time at maximum power for each call. RESULTS: Measurements of over 60,000 phone calls showed that the average output power was approximately 50% of the maximum, and that output power varied by a factor of up to 2 to 3 between study centres and network operators...

  12. Maximizing Output Power of a Solar Panel via Combination of Sun Tracking and Maximum Power Point Tracking by Fuzzy Controllers

    Directory of Open Access Journals (Sweden)

    Mohsen Taherbaneh

    2010-01-01

    Full Text Available In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar panel orientation in horizontal and vertical directions by two DC motors properly designed. A DC-DC converter is employed to track the solar panel maximum power point. In addition, the proposed system has the capability of the extraction of solar panel I-V curves. Experimental results present that the proposed fuzzy techniques result in increasing of power delivery from the solar panel, causing a reduction in size, weight, and cost of solar panels in photovoltaic systems.

  13. Maximum stress estimation model for multi-span waler beams with deflections at the supports using average strains.

    Science.gov (United States)

    Park, Sung Woo; Oh, Byung Kwan; Park, Hyo Seon

    2015-03-30

    The safety of a multi-span waler beam subjected simultaneously to a distributed load and deflections at its supports can be secured by limiting the maximum stress of the beam to a specific value to prevent the beam from reaching a limit state for failure or collapse. Despite the fact that the vast majority of accidents on construction sites occur at waler beams in retaining wall systems, no safety monitoring model that can consider deflections at the supports of the beam is available. In this paper, a maximum stress estimation model for a waler beam based on average strains measured from vibrating wire strain gauges (VWSGs), the most frequently used sensors in construction field, is presented. The model is derived by defining the relationship between the maximum stress and the average strains measured from VWSGs. In addition to the maximum stress, support reactions, deflections at supports, and the magnitudes of distributed loads for the beam structure can be identified by the estimation model using the average strains. Using simulation tests on two multi-span beams, the performance of the model is evaluated by estimating maximum stress, deflections at supports, support reactions, and the magnitudes of distributed loads.

  14. Maximum Stress Estimation Model for Multi-Span Waler Beams with Deflections at the Supports Using Average Strains

    Directory of Open Access Journals (Sweden)

    Sung Woo Park

    2015-03-01

    Full Text Available The safety of a multi-span waler beam subjected simultaneously to a distributed load and deflections at its supports can be secured by limiting the maximum stress of the beam to a specific value to prevent the beam from reaching a limit state for failure or collapse. Despite the fact that the vast majority of accidents on construction sites occur at waler beams in retaining wall systems, no safety monitoring model that can consider deflections at the supports of the beam is available. In this paper, a maximum stress estimation model for a waler beam based on average strains measured from vibrating wire strain gauges (VWSGs, the most frequently used sensors in construction field, is presented. The model is derived by defining the relationship between the maximum stress and the average strains measured from VWSGs. In addition to the maximum stress, support reactions, deflections at supports, and the magnitudes of distributed loads for the beam structure can be identified by the estimation model using the average strains. Using simulation tests on two multi-span beams, the performance of the model is evaluated by estimating maximum stress, deflections at supports, support reactions, and the magnitudes of distributed loads.

  15. A diode-pumped continuous-wave Nd:YAG laser with an average output power of 1 kW

    International Nuclear Information System (INIS)

    Lee, Sung Man; Cha, Byung Heon; Kim, Cheol Jung

    2004-01-01

    A diode-pumped Nd:YAG laser with an average output power of 1 kW is developed for industrial applications, such as metal cutting, precision welding, etc. To develop such a diode-pumped high power solid-state laser, a series of laser modules have been used in general with and without thermal birefringence compensation. For example, Akiyama et al. used three laser modules to obtain a output power of 5.4 kW CW.1 In the side-pumped Nd:YAG laser, which is a commonly used pump scheme to obtain high output power, the crystal rod has a short thermal focal length at a high input pump power, and the short thermal focal length in turn leads to beam distortion within a laser resonator. Therefore, to achieve a high output power with good stability, isotropic beam profile, and high optical efficiency, the detailed analysis of the resonator stability condition depending on both mirror distances and a crystal separation is essential

  16. Accurate computations of monthly average daily extraterrestrial irradiation and the maximum possible sunshine duration

    International Nuclear Information System (INIS)

    Jain, P.C.

    1985-12-01

    The monthly average daily values of the extraterrestrial irradiation on a horizontal plane and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by solar scientists and engineers each time they are needed and often by using the approximate short-cut methods. Using the accurate analytical expressions developed by Spencer for the declination and the eccentricity correction factor, computations for these parameters have been made for all the latitude values from 90 deg. N to 90 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Monthly average daily values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables would avoid the need for repetitive and approximate calculations and serve as a useful ready reference for providing accurate values to the solar energy scientists and engineers

  17. Dataset demonstrating the temperature effect on average output polarization for QCA based reversible logic gates

    Directory of Open Access Journals (Sweden)

    Md. Kamrul Hassan

    2017-08-01

    Full Text Available Quantum-dot cellular automata (QCA is a developing nanotechnology, which seems to be a good candidate to replace the conventional complementary metal-oxide-semiconductor (CMOS technology. In this article, we present the dataset of average output polarization (AOP for basic reversible logic gates presented in Ali Newaz et al. (2016 [1]. QCADesigner 2.0.3 has been employed to analysis the AOP of reversible gates at different temperature levels in Kelvin (K unit.

  18. Output power distributions of terminals in a 3G mobile communication network.

    Science.gov (United States)

    Persson, Tomas; Törnevik, Christer; Larsson, Lars-Eric; Lovén, Jan

    2012-05-01

    The objective of this study was to examine the distribution of the output power of mobile phones and other terminals connected to a 3G network in Sweden. It is well known that 3G terminals can operate with very low output power, particularly for voice calls. Measurements of terminal output power were conducted in the Swedish TeliaSonera 3G network in November 2008 by recording network statistics. In the analysis, discrimination was made between rural, suburban, urban, and dedicated indoor networks. In addition, information about terminal output power was possible to collect separately for voice and data traffic. Information from six different Radio Network Controllers (RNCs) was collected during at least 1 week. In total, more than 800000 h of voice calls were collected and in addition to that a substantial amount of data traffic. The average terminal output power for 3G voice calls was below 1 mW for any environment including rural, urban, and dedicated indoor networks. This is <1% of the maximum available output power. For data applications the average output power was about 6-8 dB higher than for voice calls. For rural areas the output power was about 2 dB higher, on average, than in urban areas. Copyright © 2011 Wiley Periodicals, Inc.

  19. Real-time prediction models for output power and efficiency of grid-connected solar photovoltaic systems

    International Nuclear Information System (INIS)

    Su, Yan; Chan, Lai-Cheong; Shu, Lianjie; Tsui, Kwok-Leung

    2012-01-01

    Highlights: ► We develop online prediction models for solar photovoltaic system performance. ► The proposed prediction models are simple but with reasonable accuracy. ► The maximum monthly average minutely efficiency varies 10.81–12.63%. ► The average efficiency tends to be slightly higher in winter months. - Abstract: This paper develops new real time prediction models for output power and energy efficiency of solar photovoltaic (PV) systems. These models were validated using measured data of a grid-connected solar PV system in Macau. Both time frames based on yearly average and monthly average are considered. It is shown that the prediction model for the yearly/monthly average of the minutely output power fits the measured data very well with high value of R 2 . The online prediction model for system efficiency is based on the ratio of the predicted output power to the predicted solar irradiance. This ratio model is shown to be able to fit the intermediate phase (9 am to 4 pm) very well but not accurate for the growth and decay phases where the system efficiency is near zero. However, it can still serve as a useful purpose for practitioners as most PV systems work in the most efficient manner over this period. It is shown that the maximum monthly average minutely efficiency varies over a small range of 10.81% to 12.63% in different months with slightly higher efficiency in winter months.

  20. Countermovement depth - a variable which clarifies the relationship between the maximum power output and height of a vertical jump.

    Science.gov (United States)

    Gajewski, Jan; Michalski, Radosław; Buśko, Krzysztof; Mazur-Różycka, Joanna; Staniak, Zbigniew

    2018-01-01

    The aim of this study was to identify the determinants of peak power achieved during vertical jumps in order to clarify relationship between the height of jump and the ability to exert maximum power. One hundred young (16.8±1.8 years) sportsmen participated in the study (body height 1.861 ± 0.109 m, body weight 80.3 ± 9.2 kg). Each participant performed three jump tests: countermovement jump (CMJ), akimbo countermovement jump (ACMJ), and spike jump (SPJ). A force plate was used to measure ground reaction force and to determine peak power output. The following explanatory variables were included in the model: jump height, body mass, and the lowering of the centre of mass before launch (countermovement depth). A model was created using multiple regression analysis and allometric scaling. The model was used to calculate the expected power value for each participant, which correlated strongly with real values. The value of the coefficient of determination R2 equalled 0.89, 0.90 and 0.98, respectively, for the CMJ, ACMJ, and SPJ jumps. The countermovement depth proved to be a variable strongly affecting the maximum power of jump. If the countermovement depth remains constant, the relative peak power is a simple function of jump height. The results suggest that the jump height of an individual is an exact indicator of their ability to produce maximum power. The presented model has a potential to be utilized under field condition for estimating the maximum power output of vertical jumps.

  1. An Invariance Property for the Maximum Likelihood Estimator of the Parameters of a Gaussian Moving Average Process

    OpenAIRE

    Godolphin, E. J.

    1980-01-01

    It is shown that the estimation procedure of Walker leads to estimates of the parameters of a Gaussian moving average process which are asymptotically equivalent to the maximum likelihood estimates proposed by Whittle and represented by Godolphin.

  2. Maximum power analysis of photovoltaic module in Ramadi city

    Energy Technology Data Exchange (ETDEWEB)

    Shahatha Salim, Majid; Mohammed Najim, Jassim [College of Science, University of Anbar (Iraq); Mohammed Salih, Salih [Renewable Energy Research Center, University of Anbar (Iraq)

    2013-07-01

    Performance of photovoltaic (PV) module is greatly dependent on the solar irradiance, operating temperature, and shading. Solar irradiance can have a significant impact on power output of PV module and energy yield. In this paper, a maximum PV power which can be obtain in Ramadi city (100km west of Baghdad) is practically analyzed. The analysis is based on real irradiance values obtained as the first time by using Soly2 sun tracker device. Proper and adequate information on solar radiation and its components at a given location is very essential in the design of solar energy systems. The solar irradiance data in Ramadi city were analyzed based on the first three months of 2013. The solar irradiance data are measured on earth's surface in the campus area of Anbar University. Actual average data readings were taken from the data logger of sun tracker system, which sets to save the average readings for each two minutes and based on reading in each one second. The data are analyzed from January to the end of March-2013. Maximum daily readings and monthly average readings of solar irradiance have been analyzed to optimize the output of photovoltaic solar modules. The results show that the system sizing of PV can be reduced by 12.5% if a tracking system is used instead of fixed orientation of PV modules.

  3. On the average complexity of sphere decoding in lattice space-time coded multiple-input multiple-output channel

    KAUST Repository

    Abediseid, Walid

    2012-12-21

    The exact average complexity analysis of the basic sphere decoder for general space-time codes applied to multiple-input multiple-output (MIMO) wireless channel is known to be difficult. In this work, we shed the light on the computational complexity of sphere decoding for the quasi- static, lattice space-time (LAST) coded MIMO channel. Specifically, we drive an upper bound of the tail distribution of the decoder\\'s computational complexity. We show that when the computational complexity exceeds a certain limit, this upper bound becomes dominated by the outage probability achieved by LAST coding and sphere decoding schemes. We then calculate the minimum average computational complexity that is required by the decoder to achieve near optimal performance in terms of the system parameters. Our results indicate that there exists a cut-off rate (multiplexing gain) for which the average complexity remains bounded. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Muscle power output properties using the stretch-shortening cycle of the upper limb and their relationships with a one-repetition maximum bench press.

    Science.gov (United States)

    Miyaguchi, Kazuyoshi; Demura, Shinichi

    2006-05-01

    The purpose of this study was to examine the output properties of muscle power by the dominant upper limb using SSC, and the relationships between the power output by SSC and a one-repetition maximum bench press (1 RM BP) used as a strength indicator of the upper body. Sixteen male athletes (21.4+/-0.9 yr) participated in this study. They pulled a load of 40% of maximum voluntary contraction (MVC) at a stretch by elbow flexion of the dominant upper limb in the following three preliminary conditions: static relaxed muscle state (SR condition), isometric muscle contraction state (ISO condition), and using SSC (SSC condition). The velocity with a wire load via a pulley during elbow flexion was measured accurately using a power instrument with a rotary encoder, and the muscle power curve was drawn from the product of the velocity and load. Significant differences were found among all evaluation parameters of muscle power exerted from the above three conditions and the parameters regarding early power output during concentric contraction were larger in the SSC condition than the SR and ISO conditions. The parameters on initial muscle contraction velocity when only using SSC significantly correlated with 1 RM BP (r=0.60-0.62). The use of SSC before powerful elbow flexion may contribute largely to early explosive power output during concentric contraction. Bench press capacity relates to a development of the above early power output when using SSC.

  5. Average output polarization dataset for signifying the temperature influence for QCA designed reversible logic circuits.

    Science.gov (United States)

    Abdullah-Al-Shafi, Md; Bahar, Ali Newaz; Bhuiyan, Mohammad Maksudur Rahman; Shamim, S M; Ahmed, Kawser

    2018-08-01

    Quantum-dot cellular automata (QCA) as nanotechnology is a pledging contestant that has incredible prospective to substitute complementary metal-oxide-semiconductor (CMOS) because of its superior structures such as intensely high device thickness, minimal power depletion with rapid operation momentum. In this study, the dataset of average output polarization (AOP) for fundamental reversible logic circuits is organized as presented in (Abdullah-Al-Shafi and Bahar, 2017; Bahar et al., 2016; Abdullah-Al-Shafi et al., 2015; Abdullah-Al-Shafi, 2016) [1-4]. QCADesigner version 2.0.3 has been utilized to survey the AOP of reversible circuits at separate temperature point in Kelvin (K) unit.

  6. Maximum Power Output of Quantum Heat Engine with Energy Bath

    Directory of Open Access Journals (Sweden)

    Shengnan Liu

    2016-05-01

    Full Text Available The difference between quantum isoenergetic process and quantum isothermal process comes from the violation of the law of equipartition of energy in the quantum regime. To reveal an important physical meaning of this fact, here we study a special type of quantum heat engine consisting of three processes: isoenergetic, isothermal and adiabatic processes. Therefore, this engine works between the energy and heat baths. Combining two engines of this kind, it is possible to realize the quantum Carnot engine. Furthermore, considering finite velocity of change of the potential shape, here an infinite square well with moving walls, the power output of the engine is discussed. It is found that the efficiency and power output are both closely dependent on the initial and final states of the quantum isothermal process. The performance of the engine cycle is shown to be optimized by control of the occupation probability of the ground state, which is determined by the temperature and the potential width. The relation between the efficiency and power output is also discussed.

  7. Table for monthly average daily extraterrestrial irradiation on horizontal surface and the maximum possible sunshine duration

    International Nuclear Information System (INIS)

    Jain, P.C.

    1984-01-01

    The monthly average daily values of the extraterrestrial irradiation on a horizontal surface (H 0 ) and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by scientists each time they are needed and by using the approximate short-cut methods. Computations for these values have been made once and for all for latitude values of 60 deg. N to 60 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables should avoid the need for repetition and approximate calculations and serve as a useful ready reference for solar energy scientists and engineers. (author)

  8. LOAD THAT MAXIMIZES POWER OUTPUT IN COUNTERMOVEMENT JUMP

    Directory of Open Access Journals (Sweden)

    Pedro Jimenez-Reyes

    2016-02-01

    Full Text Available ABSTRACT Introduction: One of the main problems faced by strength and conditioning coaches is the issue of how to objectively quantify and monitor the actual training load undertaken by athletes in order to maximize performance. It is well known that performance of explosive sports activities is largely determined by mechanical power. Objective: This study analysed the height at which maximal power output is generated and the corresponding load with which is achieved in a group of male-trained track and field athletes in the test of countermovement jump (CMJ with extra loads (CMJEL. Methods: Fifty national level male athletes in sprinting and jumping performed a CMJ test with increasing loads up to a height of 16 cm. The relative load that maximized the mechanical power output (Pmax was determined using a force platform and lineal encoder synchronization and estimating the power by peak power, average power and flight time in CMJ. Results: The load at which the power output no longer existed was at a height of 19.9 ± 2.35, referring to a 99.1 ± 1% of the maximum power output. The load that maximizes power output in all cases has been the load with which an athlete jump a height of approximately 20 cm. Conclusion: These results highlight the importance of considering the height achieved in CMJ with extra load instead of power because maximum power is always attained with the same height. We advise for the preferential use of the height achieved in CMJEL test, since it seems to be a valid indicative of an individual's actual neuromuscular potential providing a valid information for coaches and trainers when assessing the performance status of our athletes and to quantify and monitor training loads, measuring only the height of the jump in the exercise of CMJEL.

  9. Cut-off Grade Optimization for Maximizing the Output Rate

    Directory of Open Access Journals (Sweden)

    A. Khodayari

    2012-12-01

    Full Text Available In the open-pit mining, one of the first decisions that must be made in production planning stage, after completing the design of final pit limits, is determining of the processing plant cut-off grade. Since this grade has an essential effect on operations, choosing the optimum cut-off grade is of considerable importance. Different goals may be used for determining optimum cut-off grade. One of these goals may be maximizing the output rate (amount of product per year, which is very important, especially from marketing and market share points of view. Objective of this research is determining the optimum cut-off grade of processing plant in order to maximize output rate. For performing this optimization, an Operations Research (OR model has been developed. The object function of this model is output rate that must be maximized. This model has two operational constraints namely mining and processing restrictions. For solving the model a heuristic method has been developed. Results of research show that the optimum cut-off grade for satisfying pre-stated goal is the balancing grade of mining and processing operations, and maximum production rate is a function of the maximum capacity of processing plant and average grade of ore that according to the above optimum cut-off grade must be sent to the plant.

  10. Combining site occupancy, breeding population sizes and reproductive success to calculate time-averaged reproductive output of different habitat types: an application to Tricolored Blackbirds.

    Directory of Open Access Journals (Sweden)

    Marcel Holyoak

    Full Text Available In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005-2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent

  11. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  12. Characterization of the electrical output of flat-plate photovoltaic arrays

    Science.gov (United States)

    Gonzalez, C. C.; Hill, G. M.; Ross, R. G., Jr.

    1982-01-01

    The electric output of flat-plate photovoltaic arrays changes constantly, due primarily to changes in cell temperature and irradiance level. As a result, array loads such as direct-current to alternating-current power conditioners must be able to accommodate widely varying input levels, while maintaining operation at or near the array maximum power point.The results of an extensive computer simulation study that was used to define the parameters necessary for the systematic design of array/power-conditioner interfaces are presented as normalized ratios of power-conditioner parameters to array parameters, to make the results universally applicable to a wide variety of system sizes, sites, and operating modes. The advantages of maximum power tracking and a technique for computing average annual power-conditioner efficiency are discussed.

  13. Quantifying walking and standing behaviour of dairy cows using a moving average based on output from an accelerometer

    DEFF Research Database (Denmark)

    Nielsen, Lars Relund; Pedersen, Asger Roer; Herskin, Mette S

    2010-01-01

    in sequences of approximately 20 s for the period of 10 min. Afterwards the cows were stimulated to move/lift the legs while standing in a cubicle. The behaviour was video recorded, and the recordings were analysed second by second for walking and standing behaviour as well as the number of steps taken....... Various algorithms for predicting walking/standing status were compared. The algorithms were all based on a limit of a moving average calculated by using one of two outputs of the accelerometer, either a motion index or a step count, and applied over periods of 3 or 5 s. Furthermore, we investigated...... the effect of additionally applying the rule: a walking period must last at least 5 s. The results indicate that the lowest misclassification rate (10%) of walking and standing was obtained based on the step count with a moving average of 3 s and with the rule applied. However, the rate of misclassification...

  14. Performance study of highly efficient 520 W average power long pulse ceramic Nd:YAG rod laser

    Science.gov (United States)

    Choubey, Ambar; Vishwakarma, S. C.; Ali, Sabir; Jain, R. K.; Upadhyaya, B. N.; Oak, S. M.

    2013-10-01

    We report the performance study of a 2% atomic doped ceramic Nd:YAG rod for long pulse laser operation in the millisecond regime with pulse duration in the range of 0.5-20 ms. A maximum average output power of 520 W with 180 J maximum pulse energy has been achieved with a slope efficiency of 5.4% using a dual rod configuration, which is the highest for typical lamp pumped ceramic Nd:YAG lasers. The laser output characteristics of the ceramic Nd:YAG rod were revealed to be nearly equivalent or superior to those of high-quality single crystal Nd:YAG rod. The laser pump chamber and resonator were designed and optimized to achieve a high efficiency and good beam quality with a beam parameter product of 16 mm mrad (M2˜47). The laser output beam was efficiently coupled through a 400 μm core diameter optical fiber with 90% overall transmission efficiency. This ceramic Nd:YAG laser will be useful for various material processing applications in industry.

  15. System for memorizing maximum values

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1992-08-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either linear or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  16. Comparison of x-ray output of inverter-type x-ray equipment

    International Nuclear Information System (INIS)

    Asano, Hiroshi; Miyake, Hiroyuki; Yamamoto, Keiichi

    2000-01-01

    The x-ray output of 54 inverter-type x-ray apparatuses used at 18 institutions was investigated. The reproducibility and linearity of x-ray output and variations among the x-ray equipment were evaluated using the same fluorescence meter. In addition, the x-ray apparatuses were re-measured using the same non-invasive instrument to check for variations in tube voltage, tube current, and irradiation time. The non-invasive instrument was calibrated by simultaneously obtaining measurements with an invasive instrument, employing the tube voltage and current used for the invasive instrument, and the difference was calculated. Reproducibility of x-ray output was satisfactory for all x-ray apparatuses. The coefficient of variation was 0.04 or less for irradiation times of 5 ms or longer. In 84.3% of all x-ray equipment, variation in the linearity of x-ray output was 15% or less for an irradiation time of 5 ms. However, for all the apparatuses, the figure was 50% when irradiation time was the shortest (1 to 3 ms). Variation in x-ray output increased as irradiation time decreased. Variation in x-ray output ranged between 1.8 and 2.5 compared with the maximum and minimum values, excluding those obtained at the shortest irradiation time. The relative standard deviation ranged from ±15.5% to ±21.0%. The largest variation in x-ray output was confirmed in regions irradiated for the shortest time, with smaller variations observed for longer irradiation times. The major factor responsible for variation in x-ray output in regions irradiated for 10 ms or longer, which is a relatively long irradiation time, was variation in tube current. Variation in tube current was slightly greater than 30% at maximum, with an average value of 7% compared with the preset tube current. Variations in x-ray output in regions irradiated for the shortest time were due to photographic effects related to the rise and fall times of the tube voltage waveform. Accordingly, in order to obtain constant x

  17. Maximum Power Point Tracking (MPPT Pada Sistem Pembangkit Listrik Tenaga Angin Menggunakan Buck-Boost Converter

    Directory of Open Access Journals (Sweden)

    Muhamad Otong

    2017-05-01

    Full Text Available In this paper, the implementation of the Maximum Power Point Tracking (MPPT technique is developed using buck-boost converter. Perturb and observe (P&O MPPT algorithm is used to searching maximum power from the wind power plant for charging of the battery. The model used in this study is the Variable Speed Wind Turbine (VSWT with a Permanent Magnet Synchronous Generator (PMSG. Analysis, design, and modeling of wind energy conversion system has done using MATLAB/simulink. The simulation results show that the proposed MPPT produce a higher output power than the system without MPPT. The average efficiency that can be achieved by the proposed system to transfer the maximum power into battery is 90.56%.

  18. A New MPPT Control for Photovoltaic Panels by Instantaneous Maximum Power Point Tracking

    Science.gov (United States)

    Tokushima, Daiki; Uchida, Masato; Kanbei, Satoshi; Ishikawa, Hiroki; Naitoh, Haruo

    This paper presents a new maximum power point tracking control for photovoltaic (PV) panels. The control can be categorized into the Perturb and Observe (P & O) method. It utilizes instantaneous voltage ripples at PV panel output terminals caused by the switching of a chopper connected to the panel in order to identify the direction for the maximum power point (MPP). The tracking for the MPP is achieved by a feedback control of the average terminal voltage of the panel. Appropriate use of the instantaneous and the average values of the PV voltage for the separate purposes enables both the quick transient response and the good convergence with almost no ripples simultaneously. The tracking capability is verified experimentally with a 2.8 W PV panel under a controlled experimental setup. A numerical comparison with a conventional P & O confirms that the proposed control extracts much more power from the PV panel.

  19. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  20. How to average logarithmic retrievals?

    Directory of Open Access Journals (Sweden)

    B. Funke

    2012-04-01

    Full Text Available Calculation of mean trace gas contributions from profiles obtained by retrievals of the logarithm of the abundance rather than retrievals of the abundance itself are prone to biases. By means of a system simulator, biases of linear versus logarithmic averaging were evaluated for both maximum likelihood and maximum a priori retrievals, for various signal to noise ratios and atmospheric variabilities. These biases can easily reach ten percent or more. As a rule of thumb we found for maximum likelihood retrievals that linear averaging better represents the true mean value in cases of large local natural variability and high signal to noise ratios, while for small local natural variability logarithmic averaging often is superior. In the case of maximum a posteriori retrievals, the mean is dominated by the a priori information used in the retrievals and the method of averaging is of minor concern. For larger natural variabilities, the appropriateness of the one or the other method of averaging depends on the particular case because the various biasing mechanisms partly compensate in an unpredictable manner. This complication arises mainly because of the fact that in logarithmic retrievals the weight of the prior information depends on abundance of the gas itself. No simple rule was found on which kind of averaging is superior, and instead of suggesting simple recipes we cannot do much more than to create awareness of the traps related with averaging of mixing ratios obtained from logarithmic retrievals.

  1. Output power analyses for the thermodynamic cycles of thermal power plants

    International Nuclear Information System (INIS)

    Sun Chen; Cheng Xue-Tao; Liang Xin-Gang

    2014-01-01

    Thermal power plant is one of the important thermodynamic devices, which is very common in all kinds of power generation systems. In this paper, we use a new concept, entransy loss, as well as exergy destruction, to analyze the single reheating Rankine cycle unit and the single stage steam extraction regenerative Rankine cycle unit in power plants. This is the first time that the concept of entransy loss is applied to the analysis of the power plant Rankine cycles with reheating and steam extraction regeneration. In order to obtain the maximum output power, the operating conditions under variant vapor mass flow rates are optimized numerically, as well as the combustion temperatures and the off-design flow rates of the flue gas. The relationship between the output power and the exergy destruction rate and that between the output power and the entransy loss rate are discussed. It is found that both the minimum exergy destruction rate and the maximum entransy loss rate lead to the maximum output power when the combustion temperature and heat capacity flow rate of the flue gas are prescribed. Unlike the minimum exergy destruction rate, the maximum entransy loss rate is related to the maximum output power when the highest temperature and heat capacity flow rate of the flue gas are not prescribed. (general)

  2. SU-E-T-174: Evaluation of the Optimal Intensity Modulated Radiation Therapy Plans Done On the Maximum and Average Intensity Projection CTs

    Energy Technology Data Exchange (ETDEWEB)

    Jurkovic, I [University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Stathakis, S; Li, Y; Patel, A; Vincent, J; Papanikolaou, N; Mavroidis, P [Cancer Therapy and Research Center University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States)

    2014-06-01

    Purpose: To determine the difference in coverage between plans done on average intensity projection and maximum intensity projection CT data sets for lung patients and to establish correlations between different factors influencing the coverage. Methods: For six lung cancer patients, 10 phases of equal duration through the respiratory cycle, the maximum and average intensity projections (MIP and AIP) from their 4DCT datasets were obtained. MIP and AIP datasets had three GTVs delineated (GTVaip — delineated on AIP, GTVmip — delineated on MIP and GTVfus — delineated on each of the 10 phases and summed up). From the each GTV, planning target volumes (PTV) were then created by adding additional margins. For each of the PTVs an IMRT plan was developed on the AIP dataset. The plans were then copied to the MIP data set and were recalculated. Results: The effective depths in AIP cases were significantly smaller than in MIP (p < 0.001). The Pearson correlation coefficient of r = 0.839 indicates strong degree of positive linear relationship between the average percentage difference in effective depths and average PTV coverage on the MIP data set. The V2 0 Gy of involved lung depends on the PTV coverage. The relationship between PTVaip mean CT number difference and PTVaip coverage on MIP data set gives r = 0.830. When the plans are produced on MIP and copied to AIP, r equals −0.756. Conclusion: The correlation between the AIP and MIP data sets indicates that the selection of the data set for developing the treatment plan affects the final outcome (cases with high average percentage difference in effective depths between AIP and MIP should be calculated on AIP). The percentage of the lung volume receiving higher dose depends on how well PTV is covered, regardless of on which set plan is done.

  3. Maximum Power from a Solar Panel

    Directory of Open Access Journals (Sweden)

    Michael Miller

    2010-01-01

    Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

  4. Output factors and scatter ratios

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, P N; Summers, R E; Samulski, T V; Baird, L C [Allegheny General Hospital, Pittsburgh, PA (USA); Ahuja, A S; Dubuque, G L; Hendee, W R; Chhabra, A S

    1979-07-01

    Reference is made to a previous publication on output factors and scatter ratios for radiotherapy units in which it was suggested that the output factor should be included in the definitions of scatter-air ratio and tissue-maximum ratio. In the present correspondence from other authors and from the authors of the previous publication, the original definitions and the proposed changes are discussed. Radiation scatter from source and collimator degradation of beam energy and calculation of dose in tissue are considered in relation to the objective of accurate dosimetry.

  5. Technique for enhancing the power output of an electrostatic generator employing parametric resonance

    Science.gov (United States)

    Post, Richard F.

    2016-02-23

    A circuit-based technique enhances the power output of electrostatic generators employing an array of axially oriented rods or tubes or azimuthal corrugated metal surfaces for their electrodes. During generator operation, the peak voltage across the electrodes occurs at an azimuthal position that is intermediate between the position of minimum gap and maximum gap. If this position is also close to the azimuthal angle where the rate of change of capacity is a maximum, then the highest rf power output possible for a given maximum allowable voltage at the minimum gap can be attained. This rf power output is then coupled to the generator load through a coupling condenser that prevents suppression of the dc charging potential by conduction through the load. Optimized circuit values produce phase shifts in the rf output voltage that allow higher power output to occur at the same voltage limit at the minimum gap position.

  6. Comprehensive performance analyses and optimization of the irreversible thermodynamic cycle engines (TCE) under maximum power (MP) and maximum power density (MPD) conditions

    International Nuclear Information System (INIS)

    Gonca, Guven; Sahin, Bahri; Ust, Yasin; Parlak, Adnan

    2015-01-01

    This paper presents comprehensive performance analyses and comparisons for air-standard irreversible thermodynamic cycle engines (TCE) based on the power output, power density, thermal efficiency, maximum dimensionless power output (MP), maximum dimensionless power density (MPD) and maximum thermal efficiency (MEF) criteria. Internal irreversibility of the cycles occurred during the irreversible-adiabatic processes is considered by using isentropic efficiencies of compression and expansion processes. The performances of the cycles are obtained by using engine design parameters such as isentropic temperature ratio of the compression process, pressure ratio, stroke ratio, cut-off ratio, Miller cycle ratio, exhaust temperature ratio, cycle temperature ratio and cycle pressure ratio. The effects of engine design parameters on the maximum and optimal performances are investigated. - Highlights: • Performance analyses are conducted for irreversible thermodynamic cycle engines. • Comprehensive computations are performed. • Maximum and optimum performances of the engines are shown. • The effects of design parameters on performance and power density are examined. • The results obtained may be guidelines to the engine designers

  7. Alberta’s Changing Industrial Structure: Implications for Output and Income Volatility

    Directory of Open Access Journals (Sweden)

    Bev Dahlby

    2018-02-01

    : 16 other sectors in Alberta are linked to the same boom-bust cycle as the oil and gas sector. The more important diversification issue in the province is not output volatility, but the volatility of labour income. In the last 20 years, labour income has become increasingly concentrated in Alberta’s two most volatile sectors, oil and gas extraction and construction. As a result, volatility of aggregate labour income in Alberta increased by 40 per cent during that period. Rather than trying to change Alberta’s industrial mix by subsidizing industries that may only contribute to more volatility of economic output, a more sensible government approach would be to adopt policies that address the problem of labourincome volatility. That would include finding ways to expand unemployment insurance for Alberta workers, as the current federal government policy actually provides fewer supports to unemployed Albertans than it does to residents of other regions. Average weekly earnings of Albertans were 20 per cent higher than national average weekly earnings over the 2012 to 2016 period. However, maximum annual insurable earnings under EI are determined based on national average weekly earnings. Higherwage earners should have the opportunity to enrol in a voluntary supplemental EI program, and if the federal government does not want to provide it, the provincial government could. Additionally, the government can promote self-insurance among workers by expanding tax-sheltered savings products, like tax-free savings accounts, so workers can accumulate back-up funds when labour incomes are high, to help sustain them during downturns. Finally, the provincial government needs to abandon its procyclical spending patterns. That means spending less money when oil revenues are high, to avoid exacerbating labour and material shortages, and maintaining spending, rather than forced cutbacks, during downturns in the economy. That, of course, would require a great deal more political

  8. The effects of disjunct sampling and averaging time on maximum mean wind speeds

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo; Mann, J.

    2006-01-01

    Conventionally, the 50-year wind is calculated on basis of the annual maxima of consecutive 10-min averages. Very often, however, the averages are saved with a temporal spacing of several hours. We call it disjunct sampling. It may also happen that the wind speeds are averaged over a longer time...

  9. A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

    Energy Technology Data Exchange (ETDEWEB)

    Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

    2003-02-01

    Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

  10. The output, incomes and assets-capital relations in individual farms

    Directory of Open Access Journals (Sweden)

    Roma Ryś-Jurek

    2009-01-01

    Full Text Available In this article an attempt was made to analyse the output, incomes as well as other components of assets and sources that provided their financing in Polish individual farms, in comparison with farms from other EU countries. A special emphasis was put on examination of the interrelations between income, output and stocks observed within individual farms. Research was based on the FADN database that included basic information about average individual farms in years 2004-2006. The research showed, that (among other things the average output and family farm income were three times lower in Poland than the average in the Union. Also the increase of income was possible only thanks to the subsidies from the Union. According to the regression models, in Poland the positive influence on the increase of family farm income had stocks, crops and livestock output. While in the EU positive influence had crops and livestock production and negative influence had the stocks on an income’s growth.

  11. Maximum-likelihood model averaging to profile clustering of site types across discrete linear sequences.

    Directory of Open Access Journals (Sweden)

    Zhang Zhang

    2009-06-01

    Full Text Available A major analytical challenge in computational biology is the detection and description of clusters of specified site types, such as polymorphic or substituted sites within DNA or protein sequences. Progress has been stymied by a lack of suitable methods to detect clusters and to estimate the extent of clustering in discrete linear sequences, particularly when there is no a priori specification of cluster size or cluster count. Here we derive and demonstrate a maximum likelihood method of hierarchical clustering. Our method incorporates a tripartite divide-and-conquer strategy that models sequence heterogeneity, delineates clusters, and yields a profile of the level of clustering associated with each site. The clustering model may be evaluated via model selection using the Akaike Information Criterion, the corrected Akaike Information Criterion, and the Bayesian Information Criterion. Furthermore, model averaging using weighted model likelihoods may be applied to incorporate model uncertainty into the profile of heterogeneity across sites. We evaluated our method by examining its performance on a number of simulated datasets as well as on empirical polymorphism data from diverse natural alleles of the Drosophila alcohol dehydrogenase gene. Our method yielded greater power for the detection of clustered sites across a breadth of parameter ranges, and achieved better accuracy and precision of estimation of clusters, than did the existing empirical cumulative distribution function statistics.

  12. Lake Basin Fetch and Maximum Length/Width

    Data.gov (United States)

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  13. Mathematical model of accelerator output characteristics and their calculation on a computer

    International Nuclear Information System (INIS)

    Mishulina, O.A.; Ul'yanina, M.N.; Kornilova, T.V.

    1975-01-01

    A mathematical model is described of output characteristics of a linear accelerator. The model is a system of differential equations. Presence of phase limitations is a specific feature of setting the problem which makes it possible to ensure higher simulation accuracy and determine a capture coefficient. An algorithm is elaborated of computing output characteristics based upon the mathematical model suggested. A capture coefficient, coordinate expectation characterizing an average phase value of the beam particles, coordinate expectation characterizing an average value of the reverse relative velocity of the beam particles as well as dispersion of these coordinates are output characteristics of the accelerator. Calculation methods of the accelerator output characteristics are described in detail. The computations have been performed on the BESM-6 computer, the characteristics computing time being 2 min 20 sec. Relative error of parameter computation averages 10 -2

  14. High-throughput machining using high average power ultrashort pulse lasers and ultrafast polygon scanner

    Science.gov (United States)

    Schille, Joerg; Schneider, Lutz; Streek, André; Kloetzer, Sascha; Loeschner, Udo

    2016-03-01

    In this paper, high-throughput ultrashort pulse laser machining is investigated on various industrial grade metals (Aluminium, Copper, Stainless steel) and Al2O3 ceramic at unprecedented processing speeds. This is achieved by using a high pulse repetition frequency picosecond laser with maximum average output power of 270 W in conjunction with a unique, in-house developed two-axis polygon scanner. Initially, different concepts of polygon scanners are engineered and tested to find out the optimal architecture for ultrafast and precision laser beam scanning. Remarkable 1,000 m/s scan speed is achieved on the substrate, and thanks to the resulting low pulse overlap, thermal accumulation and plasma absorption effects are avoided at up to 20 MHz pulse repetition frequencies. In order to identify optimum processing conditions for efficient high-average power laser machining, the depths of cavities produced under varied parameter settings are analyzed and, from the results obtained, the characteristic removal values are specified. The maximum removal rate is achieved as high as 27.8 mm3/min for Aluminium, 21.4 mm3/min for Copper, 15.3 mm3/min for Stainless steel and 129.1 mm3/min for Al2O3 when full available laser power is irradiated at optimum pulse repetition frequency.

  15. Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

    Science.gov (United States)

    Marián, Vanderka; Katarína, Longová; Dávid, Olasz; Matúš, Krčmár; Simon, Walker

    2016-01-01

    The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax) and rate of force development over 100ms (RFD100), countermovement jump (CMJ) and squat jump (SJ) height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg) were divided into experimental (EXP; n = 36) and control (CON, n = 32) groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions). Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, psquats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term. Key points Jump squat exercise is one of many exercises to develop explosive strength that has been the focus of several researches, while the load used during the training seem to be an important factor that affects training outcomes. Experimental group improved performance in all assessed parameters, such as Fmax, RFD100, CMJ, SJ and 50 m sprint time. However, improvements in CMJ and SJ were recorded after the entire power training period and thereafter plateau occurred. The portable FitroDyne could serve as a valuable device to individualize the load that maximizes mean power output and visual feedback can be provided to athletes during the training. PMID:27803628

  16. Quantum Coherent Three-Terminal Thermoelectrics: Maximum Efficiency at Given Power Output

    Directory of Open Access Journals (Sweden)

    Robert S. Whitney

    2016-05-01

    Full Text Available This work considers the nonlinear scattering theory for three-terminal thermoelectric devices used for power generation or refrigeration. Such systems are quantum phase-coherent versions of a thermocouple, and the theory applies to systems in which interactions can be treated at a mean-field level. It considers an arbitrary three-terminal system in any external magnetic field, including systems with broken time-reversal symmetry, such as chiral thermoelectrics, as well as systems in which the magnetic field plays no role. It is shown that the upper bound on efficiency at given power output is of quantum origin and is stricter than Carnot’s bound. The bound is exactly the same as previously found for two-terminal devices and can be achieved by three-terminal systems with or without broken time-reversal symmetry, i.e., chiral and non-chiral thermoelectrics.

  17. Scale dependence of the average potential around the maximum in Φ4 theories

    International Nuclear Information System (INIS)

    Tetradis, N.; Wetterich, C.

    1992-04-01

    The average potential describes the physics at a length scale k - 1 by averaging out the degrees of freedom with characteristic moments larger than k. The dependence on k can be described by differential evolution equations. We solve these equations for the nonconvex part of the potential around the origin in φ 4 theories, in the phase with spontaneous symmetry breaking. The average potential is real and approaches the convex effective potential in the limit k → 0. Our calculation is relevant for processes for which the shape of the potential at a given scale is important, such as tunneling phenomena or inflation. (orig.)

  18. High Output Piezo/Triboelectric Hybrid Generator

    Science.gov (United States)

    Jung, Woo-Suk; Kang, Min-Gyu; Moon, Hi Gyu; Baek, Seung-Hyub; Yoon, Seok-Jin; Wang, Zhong-Lin; Kim, Sang-Woo; Kang, Chong-Yun

    2015-03-01

    Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable in term of the large scale and long-time durability of the device. Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric generator, derived from the simultaneous use of piezoelectric and triboelectric mechanisms in one press-and-release cycle. This hybrid generator combines high piezoelectric output current and triboelectric output voltage, which produces peak output voltage of ~370 V, current density of ~12 μA.cm-2, and average power density of ~4.44 mW.cm-2. The output power successfully lit up 600 LED bulbs by the application of a 0.2 N mechanical force and it charged a 10 μF capacitor to 10 V in 25 s. Beyond energy harvesting, this work will provide new opportunities for developing a small, built-in power source in self-powered electronics such as mobile electronics.

  19. High Output Piezo/Triboelectric Hybrid Generator

    Science.gov (United States)

    Jung, Woo-Suk; Kang, Min-Gyu; Moon, Hi Gyu; Baek, Seung-Hyub; Yoon, Seok-Jin; Wang, Zhong-Lin; Kim, Sang-Woo; Kang, Chong-Yun

    2015-01-01

    Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable in term of the large scale and long-time durability of the device. Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric generator, derived from the simultaneous use of piezoelectric and triboelectric mechanisms in one press-and-release cycle. This hybrid generator combines high piezoelectric output current and triboelectric output voltage, which produces peak output voltage of ~370 V, current density of ~12 μA·cm−2, and average power density of ~4.44 mW·cm−2. The output power successfully lit up 600 LED bulbs by the application of a 0.2 N mechanical force and it charged a 10 μF capacitor to 10 V in 25 s. Beyond energy harvesting, this work will provide new opportunities for developing a small, built-in power source in self-powered electronics such as mobile electronics. PMID:25791299

  20. Measurement of canine pancreatic perfusion using dynamic computed tomography: Influence of input-output vessels on deconvolution and maximum slope methods

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Miori, E-mail: miori@mx6.et.tiki.ne.jp [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Tsuji, Yoshihisa, E-mail: y.tsuji@extra.ocn.ne.jp [Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Shogoinkawara-cho 54, Sakyo-ku 606-8507 (Japan); Katabami, Nana; Shimizu, Junichiro; Lee, Ki-Ja [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Iwasaki, Toshiroh [Department of Veterinary Internal Medicine, Tokyo University of Agriculture and Technology, Saiwai-cho, 3-5-8, Fuchu 183-8509 (Japan); Miyake, Yoh-Ichi [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Yazumi, Shujiro [Digestive Disease Center, Kitano Hospital, 2-4-20 Ougi-machi, Kita-ku, Osaka 530-8480 (Japan); Chiba, Tsutomu [Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Shogoinkawara-cho 54, Sakyo-ku 606-8507 (Japan); Yamada, Kazutaka, E-mail: kyamada@obihiro.ac.jp [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan)

    2011-01-15

    Objective: We investigated whether the prerequisite of the maximum slope and deconvolution methods are satisfied in pancreatic perfusion CT and whether the measured parameters between these algorithms are correlated. Methods: We examined nine beagles injected with iohexol (200 mgI kg{sup -1}) at 5.0 ml s{sup -1}. The abdominal aorta and splenic and celiac arteries were selected as the input arteries and the splenic vein, the output veins. For the maximum slope method, we determined the arterial contrast volume of each artery by measuring the area under the curve (AUC) and compared the peak enhancement time in the pancreas with the contrast appearance time in the splenic vein. For the deconvolution method, the artery-to-vein collection rate of contrast medium was calculated. We calculated the pancreatic tissue blood flow (TBF), tissue blood volume (TBV), and mean transit time (MTT) using both algorithms and investigated their correlation based on vessel selection. Results: The artery AUC significantly decreased as it neared the pancreas (P < 0.01). In all cases, the peak time of the pancreas (11.5 {+-} 1.6) was shorter than the appearance time (14.1 {+-} 1.6) in the splenic vein. The splenic artery-vein combination exhibited the highest collection rate (91.1%) and was the only combination that was significantly correlated between TBF, TBV, and MTT in both algorithms. Conclusion: Selection of a vessel nearest to the pancreas is considered as a more appropriate prerequisite. Therefore, vessel selection is important in comparison of the semi-quantitative parameters obtained by different algorithms.

  1. Measurement of canine pancreatic perfusion using dynamic computed tomography: Influence of input-output vessels on deconvolution and maximum slope methods

    International Nuclear Information System (INIS)

    Kishimoto, Miori; Tsuji, Yoshihisa; Katabami, Nana; Shimizu, Junichiro; Lee, Ki-Ja; Iwasaki, Toshiroh; Miyake, Yoh-Ichi; Yazumi, Shujiro; Chiba, Tsutomu; Yamada, Kazutaka

    2011-01-01

    Objective: We investigated whether the prerequisite of the maximum slope and deconvolution methods are satisfied in pancreatic perfusion CT and whether the measured parameters between these algorithms are correlated. Methods: We examined nine beagles injected with iohexol (200 mgI kg -1 ) at 5.0 ml s -1 . The abdominal aorta and splenic and celiac arteries were selected as the input arteries and the splenic vein, the output veins. For the maximum slope method, we determined the arterial contrast volume of each artery by measuring the area under the curve (AUC) and compared the peak enhancement time in the pancreas with the contrast appearance time in the splenic vein. For the deconvolution method, the artery-to-vein collection rate of contrast medium was calculated. We calculated the pancreatic tissue blood flow (TBF), tissue blood volume (TBV), and mean transit time (MTT) using both algorithms and investigated their correlation based on vessel selection. Results: The artery AUC significantly decreased as it neared the pancreas (P < 0.01). In all cases, the peak time of the pancreas (11.5 ± 1.6) was shorter than the appearance time (14.1 ± 1.6) in the splenic vein. The splenic artery-vein combination exhibited the highest collection rate (91.1%) and was the only combination that was significantly correlated between TBF, TBV, and MTT in both algorithms. Conclusion: Selection of a vessel nearest to the pancreas is considered as a more appropriate prerequisite. Therefore, vessel selection is important in comparison of the semi-quantitative parameters obtained by different algorithms.

  2. Three-level grid-connected photovoltaic inverter with maximum power point tracking

    International Nuclear Information System (INIS)

    Tsang, K.M.; Chan, W.L.

    2013-01-01

    Highlight: ► This paper reports a novel 3-level grid connected photovoltaic inverter. ► The inverter features maximum power point tracking and grid current shaping. ► The inverter can be acted as an active filter and a renewable power source. - Abstract: This paper presents a systematic way of designing control scheme for a grid-connected photovoltaic (PV) inverter featuring maximum power point tracking (MPPT) and grid current shaping. Unlike conventional design, only four power switches are required to achieve three output levels and it is not necessary to use any phase-locked-loop circuitry. For the proposed scheme, a simple integral controller has been designed for the tracking of the maximum power point of a PV array based on an improved extremum seeking control method. For the grid-connected inverter, a current loop controller and a voltage loop controller have been designed. The current loop controller is designed to shape the inverter output current while the voltage loop controller can maintain the capacitor voltage at a certain level and provide a reference inverter output current for the PV inverter without affecting the maximum power point of the PV array. Experimental results are included to demonstrate the effectiveness of the tracking and control scheme.

  3. Diode-side-pumped intracavity frequency-doubled Nd:YAG/BaWO4 Raman laser generating average output power of 3.14 W at 590 nm.

    Science.gov (United States)

    Li, Shutao; Zhang, Xingyu; Wang, Qingpu; Zhang, Xiaolei; Cong, Zhenhua; Zhang, Huaijin; Wang, Jiyang

    2007-10-15

    We report a linear-cavity high-power all-solid-state Q-switched yellow laser. The laser source comprises a diode-side-pumped Nd:YAG module that produces 1064 nm fundamental radiation, an intracavity BaWO(4) Raman crystal that generates a first-Stokes laser at 1180 nm, and a KTP crystal that frequency doubles the first-Stokes laser to 590 nm. A convex-plane cavity is employed in this configuration to counteract some of the thermal effect caused by high pump power. An average output power of 3.14 W at 590 nm is obtained at a pulse repetition frequency of 10 kHz.

  4. Output levels of commercially available portable compact disc players and the potential risk to hearing.

    Science.gov (United States)

    Fligor, Brian J; Cox, L Clarke

    2004-12-01

    To measure the sound levels generated by the headphones of commercially available portable compact disc players and provide hearing healthcare providers with safety guidelines based on a theoretical noise dose model. Using a Knowles Electronics Manikin for Acoustical Research and a personal computer, output levels across volume control settings were recorded from headphones driven by a standard signal (white noise) and compared with output levels from music samples of eight different genres. Many commercially available models from different manufacturers were investigated. Several different styles of headphones (insert, supra-aural, vertical, and circumaural) were used to determine if style of headphone influenced output level. Free-field equivalent sound pressure levels measured at maximum volume control setting ranged from 91 dBA to 121 dBA. Output levels varied across manufacturers and style of headphone, although generally the smaller the headphone, the higher the sound level for a given volume control setting. Specifically, in one manufacturer, insert earphones increased output level 7-9 dB, relative to the output from stock headphones included in the purchase of the CD player. In a few headphone-CD player combinations, peak sound pressure levels exceeded 130 dB SPL. Based on measured sound pressure levels across systems and the noise dose model recommended by National Institute for Occupational Safety and Health for protecting the occupational worker, a maximum permissible noise dose would typically be reached within 1 hr of listening with the volume control set to 70% of maximum gain using supra-aural headphones. Using headphones that resulted in boosting the output level (e.g., insert earphones used in this study) would significantly decrease the maximum safe volume control setting; this effect was unpredictable from one manufacturer to another. In the interest of providing a straightforward recommendation that should protect the hearing of the majority of

  5. Analysis of the Environmental Efficiency of the Chinese Transportation Sector Using an Undesirable Output Slacks-Based Measure Data Envelopment Analysis Model

    Directory of Open Access Journals (Sweden)

    Xiaowei Song

    2015-07-01

    Full Text Available Many countries are attempting to reduce energy consumption and CO2 emissions while increasing the productivity and efficiency of their industries. An undesirable-output-oriented data envelopment analysis (DEA model with slacks-based measure (SBM was used to evaluate the changes in the environmental efficiency of the transportation sector in 30 Chinese provinces (municipalities and autonomous regions between 2003 and 2012. The potential for decreasing CO2 emissions and energy saving was also assessed. Transportation was found to be inefficient in most of the provinces and the average environmental efficiency was low (0.45. The overall average efficiency reached a maximum in 2005 and continually decreased until a minimum was reached in 2009; since then, it has increased. In general, transportation is more efficient in eastern than in central or western China. A sensitivity analysis was also carried out on the input and output indicators. Based on these findings, some policies are proposed to improve the environmental efficiency of the transportation sector in China.

  6. High-average-power diode-pumped Yb: YAG lasers

    International Nuclear Information System (INIS)

    Avizonis, P V; Beach, R; Bibeau, C M; Emanuel, M A; Harris, D G; Honea, E C; Monroe, R S; Payne, S A; Skidmore, J A; Sutton, S B

    1999-01-01

    A scaleable diode end-pumping technology for high-average-power slab and rod lasers has been under development for the past several years at Lawrence Livermore National Laboratory (LLNL). This technology has particular application to high average power Yb:YAG lasers that utilize a rod configured gain element. Previously, this rod configured approach has achieved average output powers in a single 5 cm long by 2 mm diameter Yb:YAG rod of 430 W cw and 280 W q-switched. High beam quality (M(sup 2)= 2.4) q-switched operation has also been demonstrated at over 180 W of average output power. More recently, using a dual rod configuration consisting of two, 5 cm long by 2 mm diameter laser rods with birefringence compensation, we have achieved 1080 W of cw output with an M(sup 2) value of 13.5 at an optical-to-optical conversion efficiency of 27.5%. With the same dual rod laser operated in a q-switched mode, we have also demonstrated 532 W of average power with an M(sup 2) and lt; 2.5 at 17% optical-to-optical conversion efficiency. These q-switched results were obtained at a 10 kHz repetition rate and resulted in 77 nsec pulse durations. These improved levels of operational performance have been achieved as a result of technology advancements made in several areas that will be covered in this manuscript. These enhancements to our architecture include: (1) Hollow lens ducts that enable the use of advanced cavity architectures permitting birefringence compensation and the ability to run in large aperture-filling near-diffraction-limited modes. (2) Compound laser rods with flanged-nonabsorbing-endcaps fabricated by diffusion bonding. (3) Techniques for suppressing amplified spontaneous emission (ASE) and parasitics in the polished barrel rods

  7. High Average Power, High Energy Short Pulse Fiber Laser System

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  8. A Hybrid Maximum Power Point Tracking Method for Automobile Exhaust Thermoelectric Generator

    Science.gov (United States)

    Quan, Rui; Zhou, Wei; Yang, Guangyou; Quan, Shuhai

    2017-05-01

    To make full use of the maximum output power of automobile exhaust thermoelectric generator (AETEG) based on Bi2Te3 thermoelectric modules (TEMs), taking into account the advantages and disadvantages of existing maximum power point tracking methods, and according to the output characteristics of TEMs, a hybrid maximum power point tracking method combining perturb and observe (P&O) algorithm, quadratic interpolation and constant voltage tracking method was put forward in this paper. Firstly, it searched the maximum power point with P&O algorithms and a quadratic interpolation method, then, it forced the AETEG to work at its maximum power point with constant voltage tracking. A synchronous buck converter and controller were implemented in the electric bus of the AETEG applied in a military sports utility vehicle, and the whole system was modeled and simulated with a MATLAB/Simulink environment. Simulation results demonstrate that the maximum output power of the AETEG based on the proposed hybrid method is increased by about 3.0% and 3.7% compared with that using only the P&O algorithm and the quadratic interpolation method, respectively. The shorter tracking time is only 1.4 s, which is reduced by half compared with that of the P&O algorithm and quadratic interpolation method, respectively. The experimental results demonstrate that the tracked maximum power is approximately equal to the real value using the proposed hybrid method,and it can preferentially deal with the voltage fluctuation of the AETEG with only P&O algorithm, and resolve the issue that its working point can barely be adjusted only with constant voltage tracking when the operation conditions change.

  9. Output characteristics of Stirling thermoacoustic engine

    International Nuclear Information System (INIS)

    Sun Daming; Qiu Limin; Wang Bo; Xiao Yong; Zhao Liang

    2008-01-01

    A thermoacoustic engine (TE), which converts thermal energy into acoustic power by the thermoacoustic effect, shows several advantages due to the absence of moving parts, such as high reliability and long lifetime associated with reduced manufacturing costs. Power output and efficiency are important criteria of the performance of a TE. In order to increase the acoustic power output and thermal efficiency of a Stirling TE, the acoustic power distribution in the engine is studied with the variable load method. It is found that the thermal efficiency is independent of the output locations along the engine under the same acoustic power output. Furthermore, when the pressure ratio is kept constant at one location along the TE, it is beneficial to increasing the thermal efficiency by exporting more acoustic power. With nitrogen of 2.5 MPa as working gas and the pressure ratio at the compliance of 1.20 in the experiments, the acoustic power is measured at the compliance and the resonator simultaneously. The maximum power output, thermal efficiency and exergy efficiency reach 390.0 W, 11.2% and 16.0%, which are increased by 51.4%, 24.4% and 19.4%, respectively, compared to those with a single R-C load with 750 ml reservoir at the compliance. This research will be instructive for increasing the efficiency and making full use of the acoustic energy of a TE

  10. Quality, precision and accuracy of the maximum No. 40 anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Obermeir, J. [Otech Engineering, Davis, CA (United States); Blittersdorf, D. [NRG Systems Inc., Hinesburg, VT (United States)

    1996-12-31

    This paper synthesizes available calibration data for the Maximum No. 40 anemometer. Despite its long history in the wind industry, controversy surrounds the choice of transfer function for this anemometer. Many users are unaware that recent changes in default transfer functions in data loggers are producing output wind speed differences as large as 7.6%. Comparison of two calibration methods used for large samples of Maximum No. 40 anemometers shows a consistent difference of 4.6% in output speeds. This difference is significantly larger than estimated uncertainty levels. Testing, initially performed to investigate related issues, reveals that Gill and Maximum cup anemometers change their calibration transfer functions significantly when calibrated in the open atmosphere compared with calibration in a laminar wind tunnel. This indicates that atmospheric turbulence changes the calibration transfer function of cup anemometers. These results call into question the suitability of standard wind tunnel calibration testing for cup anemometers. 6 refs., 10 figs., 4 tabs.

  11. Analysis and Minimization of Output Current Ripple for Discontinuous Pulse-Width Modulation Techniques in Three-Phase Inverters

    Directory of Open Access Journals (Sweden)

    Gabriele Grandi

    2016-05-01

    Full Text Available This paper gives the complete analysis of the output current ripple in three-phase voltage source inverters considering the different discontinuous pulse-width modulation (DPWM strategies. In particular, peak-to-peak current ripple amplitude is analytically evaluated over the fundamental period and compared among the most used DPWMs, including positive and negative clamped (DPWM+ and DPWM−, and the four possible combinations between them, usually named as DPWM0, DPWM1, DPWM2, and DPWM3. The maximum and the average values of peak-to-peak current ripple are estimated, and a simple method to correlate the ripple envelope with the ripple rms is proposed and verified. Furthermore, all the results obtained by DPWMs are compared to the centered pulse-width modulation (CPWM, equivalent to the space vector modulation to identify the optimal pulse-width modulation (PWM strategy as a function of the modulation index, taking into account the different average switching frequency. In this way, the PWM technique providing for the minimum output current ripple is identified over the whole modulation range. The analytical developments and the main results are experimentally verified by current ripple measurements with a three-phase PWM inverter prototype supplying an induction motor load.

  12. The effect of relative humidity on output performance of inclined and ...

    African Journals Online (AJOL)

    The set-up of 70 Watts solar panel was inclined stationary at 150 for maximum solar reception while the set-up of 80 Watts solar panel had automatic solar tracker for effective capturing of solar radiation. For 70 Watts solar panel, the maximum power output of 59.99 Watt was obtained when the relative humidity was 30%.

  13. A Monte Carlo study on multiple output stochastic frontiers

    DEFF Research Database (Denmark)

    Henningsen, Geraldine; Henningsen, Arne; Jensen, Uwe

    2015-01-01

    , dividing all other output quantities by the selected outputquantity, and using these ratios as regressors (OD). Another approach is the stochasticray production frontier (SR), which transforms the output quantities into their Euclideandistance as the dependent variable and their polar coordinates...... of the approaches is clearly superior. However, considerable differences are found between the estimates at single replications. Taking average efficiencies from both approaches gives clearly better efficiency estimates than taking just the OD or the SR. In the case of zero values in the output quantities, the SR...

  14. Appropriatie spatial scales to achieve model output uncertainty goals

    NARCIS (Netherlands)

    Booij, Martijn J.; Melching, Charles S.; Chen, Xiaohong; Chen, Yongqin; Xia, Jun; Zhang, Hailun

    2008-01-01

    Appropriate spatial scales of hydrological variables were determined using an existing methodology based on a balance in uncertainties from model inputs and parameters extended with a criterion based on a maximum model output uncertainty. The original methodology uses different relationships between

  15. Forecasted Changes in West Africa Photovoltaic Energy Output by 2045

    Directory of Open Access Journals (Sweden)

    Serge Dimitri Yikwe Buri Bazyomo

    2016-10-01

    Full Text Available The impacts of climate change on photovoltaic (PV output in the fifteen countries of the Economic Community of West African States (ECOWAS was analyzed in this paper. Using a set of eight climate models, the trends of solar radiation and temperature between 2006–2100 were examined. Assuming a lifetime of 40 years, the future changes of photovoltaic energy output for the tilted plane receptor compared to 2006–2015 were computed for the whole region. The results show that the trends of solar irradiation are negative except for the Irish Centre for High-End Computing model which predicts a positive trend with a maximum value of 0.17 W/m2/year for Cape Verde and the minimum of −0.06 W/m2/year for Liberia. The minimum of the negative trend is −0.18 W/m2/year predicted by the Model for Interdisciplinary Research on Climate (MIROC, developed at the University of Tokyo Center for Climate System Research for Cape Verde. Furthermore, temperature trends are positive with a maximum of 0.08 K/year predicted by MIROC for Niger and minimum of 0.03 K/year predicted by Nature Conservancy of Canada (NCC, Max Planck Institute (MPI for Climate Meteorology at Hamburg, French National Meteorological Research Center (CNRM and Canadian Centre for Climate Modelling and Analysis (CCCMA for Cape Verde. Photovolataic energy output changes show increasing trends in Sierra Leone with 0.013%/year as the maximum. Climate change will lead to a decreasing trend of PV output in the rest of the countries with a minimum of 0.032%/year in Niger.

  16. Thin disk laser with unstable resonator and reduced output coupler

    Science.gov (United States)

    Gavili, Anwar; Shayganmanesh, Mahdi

    2018-05-01

    In this paper, feasibility of using unstable resonator with reduced output coupling in a thin disk laser is studied theoretically. Unstable resonator is modeled by wave-optics using Collins integral and iterative method. An Yb:YAG crystal with 250 micron thickness is considered as a quasi-three level active medium and modeled by solving rate equations of energy levels populations. The amplification of laser beam in the active medium is calculated based on the Beer-Lambert law and Rigrod method. Using generalized beam parameters method, laser beam parameters like, width, divergence, M2 factor, output power as well as near and far-field beam profiles are calculated for unstable resonator. It is demonstrated that for thin disk laser (with single disk) in spite of the low thickness of the disk which leads to low gain factor, it is possible to use unstable resonator (with reduced output coupling) and achieve good output power with appropriate beam quality. Also, the behavior of output power and beam quality versus equivalent Fresnel number is investigated and optimized value of output coupling for maximum output power is achieved.

  17. A high speed digital signal averager for pulsed NMR

    International Nuclear Information System (INIS)

    Srinivasan, R.; Ramakrishna, J.; Ra agopalan, S.R.

    1978-01-01

    A 256-channel digital signal averager suitable for pulsed nuclear magnetic resonance spectroscopy is described. It implements 'stable averaging' algorithm and hence provides a calibrated display of the average signal at all times during the averaging process on a CRT. It has a maximum sampling rate of 2.5 μ sec and a memory capacity of 256 x 12 bit words. Number of sweeps is selectable through a front panel control in binary steps from 2 3 to 2 12 . The enhanced signal can be displayed either on a CRT or by a 3.5-digit LED display. The maximum S/N improvement that can be achieved with this instrument is 36 dB. (auth.)

  18. Quantitative Analysis Method of Output Loss due to Restriction for Grid-connected PV Systems

    Science.gov (United States)

    Ueda, Yuzuru; Oozeki, Takashi; Kurokawa, Kosuke; Itou, Takamitsu; Kitamura, Kiyoyuki; Miyamoto, Yusuke; Yokota, Masaharu; Sugihara, Hiroyuki

    Voltage of power distribution line will be increased due to reverse power flow from grid-connected PV systems. In the case of high density grid connection, amount of voltage increasing will be higher than the stand-alone grid connection system. To prevent the over voltage of power distribution line, PV system's output will be restricted if the voltage of power distribution line is close to the upper limit of the control range. Because of this interaction, amount of output loss will be larger in high density case. This research developed a quantitative analysis method for PV systems output and losses to clarify the behavior of grid connected PV systems. All the measured data are classified into the loss factors using 1 minute average of 1 second data instead of typical 1 hour average. Operation point on the I-V curve is estimated to quantify the loss due to the output restriction using module temperature, array output voltage, array output current and solar irradiance. As a result, loss due to output restriction is successfully quantified and behavior of output restriction is clarified.

  19. Maximum Likelihood, Consistency and Data Envelopment Analysis: A Statistical Foundation

    OpenAIRE

    Rajiv D. Banker

    1993-01-01

    This paper provides a formal statistical basis for the efficiency evaluation techniques of data envelopment analysis (DEA). DEA estimators of the best practice monotone increasing and concave production function are shown to be also maximum likelihood estimators if the deviation of actual output from the efficient output is regarded as a stochastic variable with a monotone decreasing probability density function. While the best practice frontier estimator is biased below the theoretical front...

  20. Maximum power point tracking: a cost saving necessity in solar energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Enslin, J H.R. [Stellenbosch Univ. (South Africa). Dept. of Electrical and Electronic Engineering

    1992-12-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking (MPPT) can improve cost effectiveness, has a higher reliability and can improve the quality of life in remote areas. A high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of between 15 and 25% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply (RAPS) systems. The advantages at large temperature variations and high power rated systems are much higher. Other advantages include optimal sizing and system monitor and control. (author).

  1. Average Revisited in Context

    Science.gov (United States)

    Watson, Jane; Chick, Helen

    2012-01-01

    This paper analyses the responses of 247 middle school students to items requiring the concept of average in three different contexts: a city's weather reported in maximum daily temperature, the number of children in a family, and the price of houses. The mixed but overall disappointing performance on the six items in the three contexts indicates…

  2. Industrial Applications of High Average Power FELS

    CERN Document Server

    Shinn, Michelle D

    2005-01-01

    The use of lasers for material processing continues to expand, and the annual sales of such lasers exceeds $1 B (US). Large scale (many m2) processing of materials require the economical production of laser powers of the tens of kilowatts, and therefore are not yet commercial processes, although they have been demonstrated. The development of FELs based on superconducting RF (SRF) linac technology provides a scaleable path to laser outputs above 50 kW in the IR, rendering these applications economically viable, since the cost/photon drops as the output power increases. This approach also enables high average power ~ 1 kW output in the UV spectrum. Such FELs will provide quasi-cw (PRFs in the tens of MHz), of ultrafast (pulsewidth ~ 1 ps) output with very high beam quality. This talk will provide an overview of applications tests by our facility's users such as pulsed laser deposition, laser ablation, and laser surface modification, as well as present plans that will be tested with our upgraded FELs. These upg...

  3. The relations between the output, income and stock in agricultural farms

    Directory of Open Access Journals (Sweden)

    Roma Ryś-Jurek

    2009-01-01

    Full Text Available In this article an attempt was made to analyse the stock, output, and incomes in individual agricultural farms in Poland, in comparison with farms from the other EU countries in the year 2006. Research was based on the FADN database. The research showed, that (among other things the Polish average individual farm had a four time lower the balance’s sum than the medium one in the EU, and the average output and family farm income were about three times lower in Poland than the average in the Union. The highest share of stock in the balance’s sum in Poland three direction of production had: permanent crops combined, specialist other field crops and specialist orchards – fruits. While in the Union the highest stock had the specialist wine. According to the regression’s models, in Poland the positive influence on the increase of family farm income had stock, crops and livestock output. In the Union positive influence on an income’s growth had crops and livestock production and negative influence had the stock.

  4. Characterizing the effects of cell settling on bioprinter output

    International Nuclear Information System (INIS)

    Pepper, Matthew E; Burg, Timothy C; Burg, Karen J L; Groff, Richard E; Seshadri, Vidya

    2012-01-01

    The time variation in bioprinter output, i.e. the number of cells per printed drop, was studied over the length of a typical printing experiment. This variation impacts the cell population size of bioprinted samples, which should ideally be consistent. The variation in output was specifically studied in the context of cell settling. The bioprinter studied is based on the thermal inkjet HP26A cartridge; however, the results are relevant to other cell delivery systems that draw fluid from a reservoir. A simple mathematical model suggests that the cell concentration in the bottom of the reservoir should increase linearly over time, up to some maximum, and that the cell output should be proportional to this concentration. Two studies were performed in which D1 murine stem cells and similarly sized polystyrene latex beads were printed. The bead output profiles were consistent with the model. The cell output profiles initially followed the increasing trend predicted by the settling model, but after several minutes the cell output peaked and then decreased. The decrease in cell output was found to be associated with the number of use cycles the cartridge had experienced. The differing results for beads and cells suggest that a biological process, such as adhesion, causes the decrease in cell output. Further work will be required to identify the exact process. (communication)

  5. SIMULATION OF NEW SIMPLE FUZZY LOGIC MAXIMUM POWER ...

    African Journals Online (AJOL)

    2010-06-30

    Jun 30, 2010 ... Basic structure photovoltaic system Solar array mathematic ... The equivalent circuit model of a solar cell consists of a current generator and a diode .... control of boost converter (tracker) such that maximum power is achieved at the output of the solar panel. Fig.11. The membership function of input. Fig.12.

  6. Science policy through stimulating scholarly output. Reanalyzing the Australian case

    Energy Technology Data Exchange (ETDEWEB)

    Van den Besselaar, P.; Heyman, U.; Sandström, U.

    2016-07-01

    There is a long standing debate about perverse effects of performance indicators. A main target is science policy using stimulation of output as instrument. The criticism is to a large extent based on a study of the Australian science policy in the early 1990s. Linda Butler studied the effects and argued that the effect was an growth of output, but also a decrease of average quality of the output. These results have been cited many times. In this paper we reanalyze this case and show that the analysis of Butler was wrong: the new Australian science policy did not only increase the output of the system, but also the quality went up. We discuss the implications. (Author)

  7. Selective effects of weight and inertia on maximum lifting.

    Science.gov (United States)

    Leontijevic, B; Pazin, N; Kukolj, M; Ugarkovic, D; Jaric, S

    2013-03-01

    A novel loading method (loading ranged from 20% to 80% of 1RM) was applied to explore the selective effects of externally added simulated weight (exerted by stretched rubber bands pulling downward), weight+inertia (external weights added), and inertia (covariation of the weights and the rubber bands pulling upward) on maximum bench press throws. 14 skilled participants revealed a load associated decrease in peak velocity that was the least associated with an increase in weight (42%) and the most associated with weight+inertia (66%). However, the peak lifting force increased markedly with an increase in both weight (151%) and weight+inertia (160%), but not with inertia (13%). As a consequence, the peak power output increased most with weight (59%), weight+inertia revealed a maximum at intermediate loads (23%), while inertia was associated with a gradual decrease in the peak power output (42%). The obtained findings could be of importance for our understanding of mechanical properties of human muscular system when acting against different types of external resistance. Regarding the possible application in standard athletic training and rehabilitation procedures, the results speak in favor of applying extended elastic bands which provide higher movement velocity and muscle power output than the usually applied weights. © Georg Thieme Verlag KG Stuttgart · New York.

  8. Operation of a quasi-optical gyrotron with a gaussian output coupler

    Energy Technology Data Exchange (ETDEWEB)

    Hogge, J.P.; Tran, T.M.; Paris, P.J.; Tran, M.Q. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1996-03-01

    The operation of a 92 GHz quasi-optical gyrotron (QOG) having a resonator formed by a spherical mirror and a diffraction grating placed in -1 order Littrow mount is presented. A power of 150 kW with a gaussian output pattern was measured. The gaussian content in the output was 98% with less than 1% of depolarization. By optimizing the magnetic field at fixed frequency, a maximum efficiency of 15% was reached. (author) 12 figs., 2 tabs., 22 refs.

  9. A study of a two stage maximum power point tracking control of a photovoltaic system under partially shaded insolation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Kenji; Takano, Ichiro; Sawada, Yoshio [Kogakuin University, Tokyo 163-8677 (Japan)

    2006-11-23

    A photovoltaic (PV) array shows relatively low output power density, and has a greatly drooping current-voltage (I-V) characteristic. Therefore, maximum power point tracking (MPPT) control is used to maximize the output power of the PV array. Many papers have been reported in relation to MPPT. However, the current-power (I-P) curve sometimes shows multi-local maximum point mode under non-uniform insolation conditions. The operating point of the PV system tends to converge to a local maximum output point which is not the real maximal output point on the I-P curve. Some papers have been also reported, trying to avoid this difficulty. However, most of those control systems become rather complicated. Then, the two stage MPPT control method is proposed in this paper to realize a relatively simple control system which can track the real maximum power point even under non-uniform insolation conditions. The feasibility of this control concept is confirmed for steady insolation as well as for rapidly changing insolation by simulation study using software PSIM and LabVIEW. (author)

  10. Smart Global Maximum Power Point Tracking Controller of Photovoltaic Module Arrays

    Directory of Open Access Journals (Sweden)

    Long-Yi Chang

    2018-03-01

    Full Text Available This study first explored the effect of shading on the output characteristics of modules in a photovoltaic module array. Next, a modified particle swarm optimization (PSO method was employed to track the maximum power point of the multiple-peak characteristic curve of the array. Through the optimization method, the weighting value and cognition learning factor decreased with an increasing number of iterations, whereas the social learning factor increased, thereby enhancing the tracking capability of a maximum power point tracker. In addition, the weighting value was slightly modified on the basis of the changes in the slope and power of the characteristic curve to increase the tracking speed and stability of the tracker. Finally, a PIC18F8720 microcontroller was coordinated with peripheral hardware circuits to realize the proposed PSO method, which was then adopted to track the maximum power point of the power–voltage (P–V output characteristic curve of the photovoltaic module array under shading. Subsequently, tests were conducted to verify that the modified PSO method exhibited favorable tracking speed and accuracy.

  11. A weak current amplifier and output circuit used in nuclear weighing scales

    International Nuclear Information System (INIS)

    Sun Jinhua; Zheng Mingquan; Wang Mingqian; Jia Changchun; Jin Hanjuan; Shi Qicun; Tang Ke

    1998-01-01

    A weak current amplifier and output circuit with a maximum nonlinear error of +-0.06% has been developed. Experiments show that it can work stably and therefore be used in nuclear industrial instruments

  12. Muscular outputs during dynamic bench press under stable versus unstable conditions.

    Science.gov (United States)

    Koshida, Sentaro; Urabe, Yukio; Miyashita, Koji; Iwai, Kanzunori; Kagimori, Aya

    2008-09-01

    Previous studies have suggested that resistance training exercise under unstable conditions decreases the isometric force output, yet little is known about its influence on muscular outputs during dynamic movement. The objective of this study was to investigate the effect of an unstable condition on power, force, and velocity outputs during the bench press. Twenty male collegiate athletes (mean age, 21.3 +/- 1.5 years; mean height, 167.7 +/- 7.7 cm; mean weight, 75.9 +/- 17.5 kg) participated in this study. Each subject attempted 3 sets of single bench presses with 50% of 1 repetition maximum (1RM) under a stable condition with a flat bench and an unstable condition with a Swiss ball. Acceleration data were obtained with an accelerometer attached to the center of a barbell shaft, and peak outputs of power, force, and velocity were computed. Although significant loss of the peak outputs was found under the unstable condition (p velocity outputs, compared with previous findings. Such small reduction rates of muscular outputs may not compromise the training effect. Prospective studies are necessary to confirm whether the resistance training under an unstable condition permits the improvement of dynamic performance and trunk stability.

  13. A MAXIMUM POWER POINT TRACKING SCHEME FOR A 1kW ...

    African Journals Online (AJOL)

    user

    knee point of PV system under variable atmospheric conditions have been ..... of the PV generator module increases, and the maximum power output increases as well. ..... Water Pumping System” A Thesis resented to the. Faculty of California ...

  14. High performance monolithic power management system with dynamic maximum power point tracking for microbial fuel cells.

    Science.gov (United States)

    Erbay, Celal; Carreon-Bautista, Salvador; Sanchez-Sinencio, Edgar; Han, Arum

    2014-12-02

    Microbial fuel cell (MFC) that can directly generate electricity from organic waste or biomass is a promising renewable and clean technology. However, low power and low voltage output of MFCs typically do not allow directly operating most electrical applications, whether it is supplementing electricity to wastewater treatment plants or for powering autonomous wireless sensor networks. Power management systems (PMSs) can overcome this limitation by boosting the MFC output voltage and managing the power for maximum efficiency. We present a monolithic low-power-consuming PMS integrated circuit (IC) chip capable of dynamic maximum power point tracking (MPPT) to maximize the extracted power from MFCs, regardless of the power and voltage fluctuations from MFCs over time. The proposed PMS continuously detects the maximum power point (MPP) of the MFC and matches the load impedance of the PMS for maximum efficiency. The system also operates autonomously by directly drawing power from the MFC itself without any external power. The overall system efficiency, defined as the ratio between input energy from the MFC and output energy stored into the supercapacitor of the PMS, was 30%. As a demonstration, the PMS connected to a 240 mL two-chamber MFC (generating 0.4 V and 512 μW at MPP) successfully powered a wireless temperature sensor that requires a voltage of 2.5 V and consumes power of 85 mW each time it transmit the sensor data, and successfully transmitted a sensor reading every 7.5 min. The PMS also efficiently managed the power output of a lower-power producing MFC, demonstrating that the PMS works efficiently at various MFC power output level.

  15. Maximum vehicle cabin temperatures under different meteorological conditions

    Science.gov (United States)

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76°C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68°C in the summer and 61°C in the spring. Cloudy days in both the spring and summer were on average approximately 10°C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses.

  16. 40 CFR 1045.140 - What is my engine's maximum engine power?

    Science.gov (United States)

    2010-07-01

    ...) Maximum engine power for an engine family is generally the weighted average value of maximum engine power... engine family's maximum engine power apply in the following circumstances: (1) For outboard or personal... value for maximum engine power from all the different configurations within the engine family to...

  17. Predicting Power Output of Upper Body using the OMNI-RES Scale

    Directory of Open Access Journals (Sweden)

    Bautista Iker J.

    2014-12-01

    Full Text Available The main aim of this study was to determine the optimal training zone for maximum power output. This was to be achieved through estimating mean bar velocity of the concentric phase of a bench press using a prediction equation. The values for the prediction equation would be obtained using OMNI-RES scale values of different loads of the bench press exercise. Sixty males ( voluntarily participated in the study and were tested using an incremental protocol on a Smith machine to determine one repetition maximum (1RM in the bench press exercise. A linear regression analysis produced a strong correlation (r = -0.94 between rating of perceived exertion (RPE and mean bar velocity (Velmean. The Pearson correlation analysis between real power output (PotReal and estimated power (PotEst showed a strong correlation coefficient of r = 0.77, significant at a level of p = 0.01. Therefore, the OMNI-RES scale can be used to predict Velmean in the bench press exercise to control the intensity of the exercise. The positive relationship between PotReal and PotEst allowed for the identification of a maximum power-training zone.

  18. High Power Tm3+-Doped Fiber Lasers Tuned by a Variable Reflective Output Coupler

    Directory of Open Access Journals (Sweden)

    Yulong Tang

    2008-01-01

    Full Text Available Wide wavelength tuning by a variable reflective output coupler is demonstrated in high-power double-clad Tm3+-doped silica fiber lasers diode-pumped at ∼790  nm. Varying the output coupling from 96% to 5%, the laser wavelength is tuned over a range of 106  nm from 1949 to 2055  nm. The output power exceeds 20  W over 90-nm range and the maximum output power is 32  W at 1949  nm for 51-W launched pump power, corresponding to a slope efficiency of ∼70%. Assisted with different fiber lengths, the tuning range is expanded to 240  nm from 1866 to 2107  nm with the output power larger than 10  W.

  19. A Study of a Two Stage Maximum Power Point Tracking Control of a Photovoltaic System under Partially Shaded Insolation Conditions

    Science.gov (United States)

    Kobayashi, Kenji; Takano, Ichiro; Sawada, Yoshio

    A photovoltaic array shows relatively low output power density, and has a greatly drooping Current-Voltage (I-V) characteristic. Therefore, Maximum Power Point Tracking (MPPT) control is used to maximize the output power of the array. Many papers have been reported in relation to MPPT. However, the Current-Power (I-P) curve sometimes shows multi-local maximum points mode under non-uniform insolation conditions. The operating point of the PV system tends to converge to a local maximum output point which is not the real maximal output point on the I-P curve. Some papers have been also reported, trying to avoid this difficulty. However most of those control systems become rather complicated. Then, the two stage MPPT control method is proposed in this paper to realize a relatively simple control system which can track the real maximum power point even under non-uniform insolation conditions. The feasibility of this control concept is confirmed for steady insolation as well as for rapidly changing insolation by simulation study using software PSIM and LabVIEW. In addition, simulated experiment confirms fundament al operation of the two stage MPPT control.

  20. 12 CFR 702.105 - Weighted-average life of investments.

    Science.gov (United States)

    2010-01-01

    ... investment funds. (1) For investments in registered investment companies (e.g., mutual funds) and collective investment funds, the weighted-average life is defined as the maximum weighted-average life disclosed, directly or indirectly, in the prospectus or trust instrument; (2) For investments in money market funds...

  1. Global-scale high-resolution ( 1 km) modelling of mean, maximum and minimum annual streamflow

    Science.gov (United States)

    Barbarossa, Valerio; Huijbregts, Mark; Hendriks, Jan; Beusen, Arthur; Clavreul, Julie; King, Henry; Schipper, Aafke

    2017-04-01

    Quantifying mean, maximum and minimum annual flow (AF) of rivers at ungauged sites is essential for a number of applications, including assessments of global water supply, ecosystem integrity and water footprints. AF metrics can be quantified with spatially explicit process-based models, which might be overly time-consuming and data-intensive for this purpose, or with empirical regression models that predict AF metrics based on climate and catchment characteristics. Yet, so far, regression models have mostly been developed at a regional scale and the extent to which they can be extrapolated to other regions is not known. We developed global-scale regression models that quantify mean, maximum and minimum AF as function of catchment area and catchment-averaged slope, elevation, and mean, maximum and minimum annual precipitation and air temperature. We then used these models to obtain global 30 arc-seconds (˜ 1 km) maps of mean, maximum and minimum AF for each year from 1960 through 2015, based on a newly developed hydrologically conditioned digital elevation model. We calibrated our regression models based on observations of discharge and catchment characteristics from about 4,000 catchments worldwide, ranging from 100 to 106 km2 in size, and validated them against independent measurements as well as the output of a number of process-based global hydrological models (GHMs). The variance explained by our regression models ranged up to 90% and the performance of the models compared well with the performance of existing GHMs. Yet, our AF maps provide a level of spatial detail that cannot yet be achieved by current GHMs.

  2. Performance analysis and comparison of an Atkinson cycle coupled to variable temperature heat reservoirs under maximum power and maximum power density conditions

    International Nuclear Information System (INIS)

    Wang, P.-Y.; Hou, S.-S.

    2005-01-01

    In this paper, performance analysis and comparison based on the maximum power and maximum power density conditions have been conducted for an Atkinson cycle coupled to variable temperature heat reservoirs. The Atkinson cycle is internally reversible but externally irreversible, since there is external irreversibility of heat transfer during the processes of constant volume heat addition and constant pressure heat rejection. This study is based purely on classical thermodynamic analysis methodology. It should be especially emphasized that all the results and conclusions are based on classical thermodynamics. The power density, defined as the ratio of power output to maximum specific volume in the cycle, is taken as the optimization objective because it considers the effects of engine size as related to investment cost. The results show that an engine design based on maximum power density with constant effectiveness of the hot and cold side heat exchangers or constant inlet temperature ratio of the heat reservoirs will have smaller size but higher efficiency, compression ratio, expansion ratio and maximum temperature than one based on maximum power. From the view points of engine size and thermal efficiency, an engine design based on maximum power density is better than one based on maximum power conditions. However, due to the higher compression ratio and maximum temperature in the cycle, an engine design based on maximum power density conditions requires tougher materials for engine construction than one based on maximum power conditions

  3. Predicting Output Power for Nearshore Wave Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Henock Mamo Deberneh

    2018-04-01

    Full Text Available Energy harvested from a Wave Energy Converter (WEC varies greatly with the location of its installation. Determining an optimal location that can result in maximum output power is therefore critical. In this paper, we present a novel approach to predicting the output power of a nearshore WEC by characterizing ocean waves using floating buoys. We monitored the movement of the buoys using an Arduino-based data collection module, including a gyro-accelerometer sensor and a wireless transceiver. The collected data were utilized to train and test prediction models. The models were developed using machine learning algorithms: SVM, RF and ANN. The results of the experiments showed that measurements from the data collection module can yield a reliable predictor of output power. Furthermore, we found that the predictors work better when the regressors are combined with a classifier. The accuracy of the proposed prediction model suggests that it could be extremely useful in both locating optimal placement for wave energy harvesting plants and designing the shape of the buoys used by them.

  4. Effect of argon plasma treatment on the output performance of triboelectric nanogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Guang-Gui, E-mail: ggcheng@ujs.edu.cn [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Jiang, Shi-Yu; Li, Kai [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Zhang, Zhong-Qiang [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Wang, Ying; Yuan, Ning-Yi [Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Ding, Jian-Ning, E-mail: dingjn@ujs.edu.cn [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Zhang, Wei [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China)

    2017-08-01

    Highlights: • Two different kinds of PDMS films were prepared by spin-coated. • The PDMS surface was plasma treated with different power and time. • The output performance of TENG was significantly enhanced by plasma treatment. • Plasma treatment effect has time-efficient, the output declines with store time. - Abstract: Physical and chemical properties of the polymer surface play great roles in the output performance of triboelectric nanogenerator (TENG). Specific texture on the surface of polymer can enlarge the contact area and enhance the power output performance of TENG. In this paper, polydimethylsiloxane (PDMS) films with smooth and micro pillar arrays on the surface were prepared respectively. The surfaces were treated by argon plasma before testing their output performance. By changing treatment parameters such as treating time and plasma power, surfaces with different roughness and their relationship were achieved. The electrical output performances of the assembled TENG for each specimen showed that argon plasma treatment has a significant etching effect on the PDMS surface and greatly strengthen its output performance. The average surface roughness of PDMS film increases with the etching time from 5 mins to 15 mins when the argon plasma power is 60 W. Nevertheless, the average surface roughness is inversely proportional to the treatment time for the power of 90W. When treated with 90 W and 5 mins, many uniform micro pillars appeared on the both PDMS surface, and the output performance of the TENG for plasma treated smooth surface is 2.6 times larger than that before treatment. The output voltage increases from 42 V to 72 V, and the short circuit current increases from 4.2 μA to 8.3 μA after plasma treatment of the micro pillar array surface. However, this plasma treatment has time-efficient due to the hydrophobic recovery property of Ar plasma treated PDMS surface, both output voltage and short circuit current decrease significantly after 3

  5. GaN Nanowire Arrays for High-Output Nanogenerators

    KAUST Repository

    Huang, Chi-Te

    2010-04-07

    Three-fold symmetrically distributed GaN nanowire (NW) arrays have been epitaxially grown on GaN/sapphire substrates. The GaN NW possesses a triangular cross section enclosed by (0001), (2112), and (2112) planes, and the angle between the GaN NW and the substrate surface is ∼62°. The GaN NW arrays produce negative output voltage pulses when scanned by a conductive atomic force microscope in contact mode. The average of piezoelectric output voltage was about -20 mV, while 5-10% of the NWs had piezoelectric output voltages exceeding -(0.15-0.35) V. The GaN NW arrays are highly stable and highly tolerate to moisture in the atmosphere. The GaN NW arrays demonstrate an outstanding potential to be utilized for piezoelectric energy generation with a performance probably better than that of ZnO NWs. © 2010 American Chemical Society.

  6. Power output and efficiency of a thermoelectric generator under temperature control

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Wu, Po-Hua; Wang, Xiao-Dong; Lin, Yu-Li

    2016-01-01

    Highlights: • Power output and efficiency of a thermoelectric generator (TEG) is studied. • Temperatures at the module’s surfaces are approximated by sinusoidal functions. • Mean output power and efficiency are enhanced by the temperature oscillation. • The maximum mean efficiency of the TEG in this study is 8.45%. • The phase angle of 180° is a feasible operation for maximizing the performance. - Abstract: Operation control is an effective way to improve the output power of thermoelectric generators (TEGs). The present study is intended to numerically investigate the power output and efficiency of a TEG and find the operating conditions for maximizing its performance. The temperature distributions at the hot side and cold side surfaces of the TEG are approximated by sinusoidal functions. The influences of the temperature amplitudes at the hot side surface and the cold side surface, the phase angle, and the figure-of-merit (ZT) on the performance of the TEG are analyzed. The predictions indicate that the mean output power and efficiency of the TEG are significantly enhanced by the temperature oscillation, whereas the mean absorbed heat by the TEG is slightly influenced. An increase in the temperature amplitude of the hot side surface and the phase angle can effectively improve the performance. For the phase angle of 0°, a smaller temperature amplitude at the cold side surface renders the better performance compared to that with a larger amplitude. When the ZT value increases from 0.736 to 1.8, the mean efficiency at the phase angle of 180° is amplified by a factor of 1.72, and the maximum mean efficiency is 8.45%. In summary, a larger temperature amplitude at the hot side surface with the phase angle of 180° is a feasible operation for maximizing the performance.

  7. The value of risk: measuring the service output of U.S. commercial banks

    OpenAIRE

    Basu, Susanto; Inklaar, Robert; Wang, J. Christina

    2011-01-01

    Rather than charging direct fees, banks often charge implicitly for their services via interest spreads. As a result, much of bank output has to be estimated indirectly. In contrast to current statistical practice, dynamic optimizing models of banks argue that compensation for bearing systematic risk is not part of bank output. We apply these models and find that between 1997 and 2007, in the U.S. National Accounts, on average, bank output is overestimated by 21 percent and GDP is overestimat...

  8. Designing an agricultural vegetative waste-management system under uncertain prices of treatment-technology output products.

    Science.gov (United States)

    Broitman, D; Raviv, O; Ayalon, O; Kan, I

    2018-05-01

    Setting up a sustainable agricultural vegetative waste-management system is a challenging investment task, particularly when markets for output products of waste-treatment technologies are not well established. We conduct an economic analysis of possible investments in treatment technologies of agricultural vegetative waste, while accounting for fluctuating output prices. Under a risk-neutral approach, we find the range of output-product prices within which each considered technology becomes most profitable, using average final prices as the exclusive factor. Under a risk-averse perspective, we rank the treatment technologies based on their computed certainty-equivalent profits as functions of the coefficient of variation of the technologies' output prices. We find the ranking of treatment technologies based on average prices to be robust to output-price fluctuations provided that the coefficient of variation of the output prices is below about 0.4, that is, approximately twice as high as that of well-established recycled-material markets such as glass, paper and plastic. We discuss some policy implications that arise from our analysis regarding vegetative waste management and its associated risks. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Modeling of Maximum Power Point Tracking Controller for Solar Power System

    Directory of Open Access Journals (Sweden)

    Aryuanto Soetedjo

    2012-09-01

    Full Text Available In this paper, a Maximum Power Point Tracking (MPPT controller for solar power system is modeled using MATLAB Simulink. The model consists of PV module, buck converter, and MPPT controller. The contribution of the work is in the modeling of buck converter that allowing the input voltage of the converter, i.e. output voltage of PV is changed by varying the duty cycle, so that the maximum power point could be tracked when the environmental changes. The simulation results show that the developed model performs well in tracking the maximum power point (MPP of the PV module using Perturb and Observe (P&O Algorithm.

  10. Does player unavailability affect football teams' match physical outputs? A two-season study of the UEFA champions league.

    Science.gov (United States)

    Windt, Johann; Ekstrand, Jan; Khan, Karim M; McCall, Alan; Zumbo, Bruno D

    2018-05-01

    Player unavailability negatively affects team performance in elite football. However, whether player unavailability and its concomitant performance decrement is mediated by any changes in teams' match physical outputs is unknown. We examined whether the number of players injured (i.e. unavailable for match selection) was associated with any changes in teams' physical outputs. Prospective cohort study. Between-team variation was calculated by correlating average team availability with average physical outputs. Within-team variation was quantified using linear mixed modelling, using physical outputs - total distance, sprint count (efforts over 20km/h), and percent of distance covered at high speeds (>14km/h) - as outcome variables, and player unavailability as the independent variable of interest. To control for other factors that may influence match physical outputs, stage (group stage/knockout), venue (home/away), score differential, ball possession (%), team ranking (UEFA Club Coefficient), and average team age were all included as covariates. Teams' average player unavailability was positively associated with the average number of sprints they performed in matches across two seasons. Multilevel models similarly demonstrated that having 4 unavailable players was associated with 20.8 more sprints during matches in 2015/2016, and with an estimated 0.60-0.77% increase in the proportion of total distance run above 14km/h in both seasons. Player unavailability had a possibly positive and likely positive association with total match distances in the two respective seasons. Having more players injured and unavailable for match selection was associated with an increase in teams' match physical outputs. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. Analysis of output trends from Varian 2100C/D and 600C/D accelerators

    International Nuclear Information System (INIS)

    Grattan, M W D; Hounsell, A R

    2011-01-01

    Analysis of Varian linear accelerator output trends is reported. Two groups, consisting of four matched Varian 2100C/D and four matched Varian 600C/D accelerators, with different designs of monitor chamber, have been investigated and the data acquired from regular calibrated ion chamber/electrometer measurements of the output performance of the eight accelerators analysed. The trend of machine output with time, having removed the effect of adjusting the monitor chamber response, was compared on a monthly and annual basis for monitor chambers with ages ranging between 1 year and 7 years. The results indicate that the response is generally consistent within each set of accelerators with different monitor chamber designs. Those used in a Varian 600C/D machine result in a reduction in measured output over time, with an average monthly reduction of 0.35 ± 0.09% over the course of the first 4 years of use. The chambers used in a 2100C/D accelerator result in an increase in measured output over time, with an average monthly increase of 0.26 ± 0.09% over the course of the first 4 years of use. The output increase then reduces towards the end of this period of time, with the average monthly change falling to -0.03 ± 0.02% for the following 3 years. The output response trend was similar for all clinical energies used on the 2100C/D accelerators--6, 15 MV x-ray beams, and 4, 6, 9, 12, 16 and 20 MeV electron beams. By tracking these changes it has been possible to predict the response over time to allow appropriate adjustments in monitor chamber response to maintain a measured accelerator output within tolerance and give confidence in performance. It has also provided data to indicate the need for planned preventative intervention and indicate if the monitor chamber response is behaving as expected. (note)

  12. Statistical downscaling of CMIP5 outputs for projecting future changes in rainfall in the Onkaparinga catchment

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Md. Mamunur, E-mail: mdmamunur.rashid@mymail.unisa.edu.au [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia); Beecham, Simon, E-mail: simon.beecham@unisa.edu.au [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia); Chowdhury, Rezaul K., E-mail: rezaulkabir@uaeu.ac.ae [Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia); Department of Civil and Environmental Engineering, United Arab Emirates University, Al Ain, PO Box 15551 (United Arab Emirates)

    2015-10-15

    A generalized linear model was fitted to stochastically downscaled multi-site daily rainfall projections from CMIP5 General Circulation Models (GCMs) for the Onkaparinga catchment in South Australia to assess future changes to hydrologically relevant metrics. For this purpose three GCMs, two multi-model ensembles (one by averaging the predictors of GCMs and the other by regressing the predictors of GCMs against reanalysis datasets) and two scenarios (RCP4.5 and RCP8.5) were considered. The downscaling model was able to reasonably reproduce the observed historical rainfall statistics when the model was driven by NCEP reanalysis datasets. Significant bias was observed in the rainfall when downscaled from historical outputs of GCMs. Bias was corrected using the Frequency Adapted Quantile Mapping technique. Future changes in rainfall were computed from the bias corrected downscaled rainfall forced by GCM outputs for the period 2041–2060 and these were then compared to the base period 1961–2000. The results show that annual and seasonal rainfalls are likely to significantly decrease for all models and scenarios in the future. The number of dry days and maximum consecutive dry days will increase whereas the number of wet days and maximum consecutive wet days will decrease. Future changes of daily rainfall occurrence sequences combined with a reduction in rainfall amounts will lead to a drier catchment, thereby reducing the runoff potential. Because this is a catchment that is a significant source of Adelaide's water supply, irrigation water and water for maintaining environmental flows, an effective climate change adaptation strategy is needed in order to face future potential water shortages. - Highlights: • A generalized linear model was used for multi-site daily rainfall downscaling. • Rainfall was downscaled from CMIP5 GCM outputs. • Two multi-model ensemble approaches were used. • Bias was corrected using the Frequency Adapted Quantile Mapping

  13. S-Band AlGaN/GaN Power Amplifier MMIC with over 20 Watt Output Power

    NARCIS (Netherlands)

    Heijningen, M. van; Visser, G.C.; Wuerfl, J.; Vliet, F.E. van

    2008-01-01

    This paper presents the design of an S-band HPA MMIC in AlGaN/GaN CPW technology for radar TR-module application. The trade-offs of using an MMIC solution versus discrete power devices are discussed. The MMIC shows a maximum output power of 38 Watt at 37% Power Added Efficiency at 3.1 GHz. An output

  14. Latitudinal Change of Tropical Cyclone Maximum Intensity in the Western North Pacific

    OpenAIRE

    Choi, Jae-Won; Cha, Yumi; Kim, Hae-Dong; Kang, Sung-Dae

    2016-01-01

    This study obtained the latitude where tropical cyclones (TCs) show maximum intensity and applied statistical change-point analysis on the time series data of the average annual values. The analysis results found that the latitude of the TC maximum intensity increased from 1999. To investigate the reason behind this phenomenon, the difference of the average latitude between 1999 and 2013 and the average between 1977 and 1998 was analyzed. In a difference of 500 hPa streamline between the two ...

  15. Predicting Power Output of Upper Body using the OMNI-RES Scale.

    Science.gov (United States)

    Bautista, Iker J; Chirosa, Ignacio J; Tamayo, Ignacio Martín; González, Andrés; Robinson, Joseph E; Chirosa, Luis J; Robertson, Robert J

    2014-12-09

    The main aim of this study was to determine the optimal training zone for maximum power output. This was to be achieved through estimating mean bar velocity of the concentric phase of a bench press using a prediction equation. The values for the prediction equation would be obtained using OMNI-RES scale values of different loads of the bench press exercise. Sixty males (age 23.61 2.81 year; body height 176.29 6.73 cm; body mass 73.28 4.75 kg) voluntarily participated in the study and were tested using an incremental protocol on a Smith machine to determine one repetition maximum (1RM) in the bench press exercise. A linear regression analysis produced a strong correlation (r = -0.94) between rating of perceived exertion (RPE) and mean bar velocity (Velmean). The Pearson correlation analysis between real power output (PotReal) and estimated power (PotEst) showed a strong correlation coefficient of r = 0.77, significant at a level of p = 0.01. Therefore, the OMNI-RES scale can be used to predict Velmean in the bench press exercise to control the intensity of the exercise. The positive relationship between PotReal and PotEst allowed for the identification of a maximum power-training zone.

  16. Optimal piston motion for maximum net output work of Daniel cam engines with low heat rejection

    International Nuclear Information System (INIS)

    Badescu, Viorel

    2015-01-01

    Highlights: • The piston motion of low heat rejection compression ignition engines is optimized. • A realistic model taking into account the cooling system is developed. • The optimized cam is smaller for cylinders without thermal insulation. • The optimized cam size depends on ignition moment and cooling process intensity. - Abstract: Compression ignition engines based on classical tapper-crank systems cannot provide optimal piston motion. Cam engines are more appropriate for this purpose. In this paper the piston motion of a Daniel cam engine is optimized. Piston acceleration is taken as a control. The objective is to maximize the net output work during the compression and power strokes. A major research effort has been allocated in the last two decades for the development of low heat rejection engines. A thermally insulated cylinder is considered and a realistic model taking into account the cooling system is developed. The sinusoidal approximation of piston motion in the classical tapper-crank system overestimates the engine efficiency. The exact description of the piston motion in tapper-crank system is used here as a reference. The radiation process has negligible effects during the optimization. The approach with no constraint on piston acceleration is a reasonable approximation. The net output work is much larger (by 12–13%) for the optimized system than for the classical tapper-crank system, for similar thickness of cylinder walls and thermal insulation. Low heat rejection measures are not of significant importance for optimized cam engines. The optimized cam is smaller for a cylinder without thermal insulation than for an insulated cylinder (by up to 8%, depending on the local polar radius). The auto-ignition moment is not a parameter of significant importance for optimized cam engines. However, for given cylinder wall and insulation materials there is an optimum auto-ignition moment which maximizes the net output work. The optimum auto

  17. A maximum power point tracking scheme for a 1kw stand-alone ...

    African Journals Online (AJOL)

    A maximum power point tracking scheme for a 1kw stand-alone solar energy based power supply. ... Nigerian Journal of Technology ... A method for efficiently maximizing the output power of a solar panel supplying a load or battery bus under ...

  18. Active structural acoustic control of helicopter interior multifrequency noise using input-output-based hybrid control

    Science.gov (United States)

    Ma, Xunjun; Lu, Yang; Wang, Fengjiao

    2017-09-01

    This paper presents the recent advances in reduction of multifrequency noise inside helicopter cabin using an active structural acoustic control system, which is based on active gearbox struts technical approach. To attenuate the multifrequency gearbox vibrations and resulting noise, a new scheme of discrete model predictive sliding mode control has been proposed based on controlled auto-regressive moving average model. Its implementation only needs input/output data, hence a broader frequency range of controlled system is modelled and the burden on the state observer design is released. Furthermore, a new iteration form of the algorithm is designed, improving the developing efficiency and run speed. To verify the algorithm's effectiveness and self-adaptability, experiments of real-time active control are performed on a newly developed helicopter model system. The helicopter model can generate gear meshing vibration/noise similar to a real helicopter with specially designed gearbox and active struts. The algorithm's control abilities are sufficiently checked by single-input single-output and multiple-input multiple-output experiments via different feedback strategies progressively: (1) control gear meshing noise through attenuating vibrations at the key points on the transmission path, (2) directly control the gear meshing noise in the cabin using the actuators. Results confirm that the active control system is practical for cancelling multifrequency helicopter interior noise, which also weakens the frequency-modulation of the tones. For many cases, the attenuations of the measured noise exceed the level of 15 dB, with maximum reduction reaching 31 dB. Also, the control process is demonstrated to be smoother and faster.

  19. Study the Output Characteristics of a 90 kJ Filippove-Type Plasma Focus

    Science.gov (United States)

    Sadat Kiai, S. M.; Talaei, A.; Adlparvar, S.; Zirak, A.; Elahi, M.; Safarian, A.; Farhangi, S.; Alhooie, S.; Dabirzadeh, A. A.; Khalaj, M. M.; Mahlooji, M. S.; Talaei, M.; KaKaei, S.; Sheibani, S.; Kashani, A.; Zahedi, F.

    2010-08-01

    The output characteristics of a Filippove-Type plasma focus "Dena" (288 μF, 25 kV, 90 kJ) is numerically investigated by considering the voltage, current, current derivative, and maximum current as a function of capacitor bank energy in the constant Argon gas pressure and compared to the experiment. It is shown that increase on the bank energy leads to the increment on the maximum current and decrement on the pinch time.

  20. Output power distributions of mobile radio base stations based on network measurements

    International Nuclear Information System (INIS)

    Colombi, D; Thors, B; Persson, T; Törnevik, C; Wirén, N; Larsson, L-E

    2013-01-01

    In this work output power distributions of mobile radio base stations have been analyzed for 2G and 3G telecommunication systems. The approach is based on measurements in selected networks using performance surveillance tools part of the network Operational Support System (OSS). For the 3G network considered, direct measurements of output power levels were possible, while for the 2G networks, output power levels were estimated from measurements of traffic volumes. Both voice and data services were included in the investigation. Measurements were conducted for large geographical areas, to ensure good overall statistics, as well as for smaller areas to investigate the impact of different environments. For high traffic hours, the 90th percentile of the averaged output power was found to be below 65% and 45% of the available output power for the 2G and 3G systems, respectively.

  1. Output power distributions of mobile radio base stations based on network measurements

    Science.gov (United States)

    Colombi, D.; Thors, B.; Persson, T.; Wirén, N.; Larsson, L.-E.; Törnevik, C.

    2013-04-01

    In this work output power distributions of mobile radio base stations have been analyzed for 2G and 3G telecommunication systems. The approach is based on measurements in selected networks using performance surveillance tools part of the network Operational Support System (OSS). For the 3G network considered, direct measurements of output power levels were possible, while for the 2G networks, output power levels were estimated from measurements of traffic volumes. Both voice and data services were included in the investigation. Measurements were conducted for large geographical areas, to ensure good overall statistics, as well as for smaller areas to investigate the impact of different environments. For high traffic hours, the 90th percentile of the averaged output power was found to be below 65% and 45% of the available output power for the 2G and 3G systems, respectively.

  2. Auxetic piezoelectric energy harvesters for increased electric power output

    Directory of Open Access Journals (Sweden)

    Qiang Li

    2017-01-01

    Full Text Available This letter presents a piezoelectric bimorph with auxetic (negative Poisson’s ratio behaviors for increased power output in vibration energy harvesting. The piezoelectric bimorph comprises a 2D auxetic substrate sandwiched between two piezoelectric layers. The auxetic substrate is capable of introducing auxetic behaviors and thus increasing the transverse stress in the piezoelectric layers when the bimorph is subjected to a longitudinal stretching load. As a result, both 31- and 32-modes are simultaneously exploited to generate electric power, leading to an increased power output. The increasing power output principle was theoretically analyzed and verified by finite element (FE modelling. The FE modelling results showed that the auxetic substrate can increase the transverse stress of a bimorph by 16.7 times. The average power generated by the auxetic bimorph is 2.76 times of that generated by a conventional bimorph.

  3. New topology of multiple-input single-output PV system for DC load applications

    Directory of Open Access Journals (Sweden)

    Mohsen M. ELhagry

    2016-12-01

    Full Text Available Improving PV system structure and maximizing the output power of a PV system has drawn many researchers attention nowadays. A proposed multi-input single-output PV system is proposed in this paper. The system consists of multiple PV modules; each module feeds a DC–DC converter. The outputs of the converters are tied together to form a DC voltage source. In order to minimize the output ripples of the converters, the control signal of each converter is time shifted from each other by a certain time interval depending on the number of converters used in the topology. In this study a battery is used as the main load, the load current used as the control variable. A fuzzy logic controller designed to modulate the operating point of the system to get the maximum power. The results show that the proposed system has very good response for various operating conditions of the PV system. In addition the output filter is minimized with excellent quality of the DC output voltage.

  4. Modelling innovation performance of European regions using multi-output neural networks.

    Science.gov (United States)

    Hajek, Petr; Henriques, Roberto

    2017-01-01

    Regional innovation performance is an important indicator for decision-making regarding the implementation of policies intended to support innovation. However, patterns in regional innovation structures are becoming increasingly diverse, complex and nonlinear. To address these issues, this study aims to develop a model based on a multi-output neural network. Both intra- and inter-regional determinants of innovation performance are empirically investigated using data from the 4th and 5th Community Innovation Surveys of NUTS 2 (Nomenclature of Territorial Units for Statistics) regions. The results suggest that specific innovation strategies must be developed based on the current state of input attributes in the region. Thus, it is possible to develop appropriate strategies and targeted interventions to improve regional innovation performance. We demonstrate that support of entrepreneurship is an effective instrument of innovation policy. We also provide empirical support that both business and government R&D activity have a sigmoidal effect, implying that the most effective R&D support should be directed to regions with below-average and average R&D activity. We further show that the multi-output neural network outperforms traditional statistical and machine learning regression models. In general, therefore, it seems that the proposed model can effectively reflect both the multiple-output nature of innovation performance and the interdependency of the output attributes.

  5. Modelling innovation performance of European regions using multi-output neural networks.

    Directory of Open Access Journals (Sweden)

    Petr Hajek

    Full Text Available Regional innovation performance is an important indicator for decision-making regarding the implementation of policies intended to support innovation. However, patterns in regional innovation structures are becoming increasingly diverse, complex and nonlinear. To address these issues, this study aims to develop a model based on a multi-output neural network. Both intra- and inter-regional determinants of innovation performance are empirically investigated using data from the 4th and 5th Community Innovation Surveys of NUTS 2 (Nomenclature of Territorial Units for Statistics regions. The results suggest that specific innovation strategies must be developed based on the current state of input attributes in the region. Thus, it is possible to develop appropriate strategies and targeted interventions to improve regional innovation performance. We demonstrate that support of entrepreneurship is an effective instrument of innovation policy. We also provide empirical support that both business and government R&D activity have a sigmoidal effect, implying that the most effective R&D support should be directed to regions with below-average and average R&D activity. We further show that the multi-output neural network outperforms traditional statistical and machine learning regression models. In general, therefore, it seems that the proposed model can effectively reflect both the multiple-output nature of innovation performance and the interdependency of the output attributes.

  6. Dynamic performance of maximum power point tracking circuits using sinusoidal extremum seeking control for photovoltaic generation

    Science.gov (United States)

    Leyva, R.; Artillan, P.; Cabal, C.; Estibals, B.; Alonso, C.

    2011-04-01

    The article studies the dynamic performance of a family of maximum power point tracking circuits used for photovoltaic generation. It revisits the sinusoidal extremum seeking control (ESC) technique which can be considered as a particular subgroup of the Perturb and Observe algorithms. The sinusoidal ESC technique consists of adding a small sinusoidal disturbance to the input and processing the perturbed output to drive the operating point at its maximum. The output processing involves a synchronous multiplication and a filtering stage. The filter instance determines the dynamic performance of the MPPT based on sinusoidal ESC principle. The approach uses the well-known root-locus method to give insight about damping degree and settlement time of maximum-seeking waveforms. This article shows the transient waveforms in three different filter instances to illustrate the approach. Finally, an experimental prototype corroborates the dynamic analysis.

  7. Novel high efficient speed sensorless controller for maximum power extraction from wind energy conversion systems

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2016-01-01

    Highlights: • Novel sensorless MPPT technique without drawbacks of other sensor/sensorless methods. • Tracking the actual MPP of WECSs, no tracking the MPP of their wind turbines. • Actually extracting the highest output power from WECSs. • Novel MPPT technique having the MPPT efficiency more than 98.5% for WECSs. • Novel MPPT technique having short convergence time for WECSs. - Abstract: In this study, a novel high accurate sensorless maximum power point tracking (MPPT) method is proposed. The technique tracks the actual maximum power point of a wind energy conversion system (WECS) at which maximum output power is extracted from the system, not the maximum power point of its wind turbine at which maximum mechanical power is obtained from the turbine, so it actually extracts the highest output power from the system. The technique only uses input voltage and current of the converter used in the system, and neither needs any speed sensors (anemometer and tachometer) nor has the drawbacks of other sensor/sensorless based MPPT methods. The technique has been implemented as a MPPT controller by constructing a WECS. Theoretical results, the technique performance, and its advantages are validated by presenting real experimental results. The real static-dynamic response of the MPPT controller is experimentally obtained that verifies the proposed MPPT technique high accurately extracts the highest instant power from wind energy conversion systems with the MPPT efficiency of more than 98.5% and a short convergence time that is only 25 s for the constructed system having a total inertia and friction coefficient of 3.93 kg m 2 and 0.014 N m s, respectively.

  8. Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

    Directory of Open Access Journals (Sweden)

    Vanderka Marián, Longová Katarína, Olasz Dávid, Krčmár Matúš, Walker Simon

    2016-09-01

    Full Text Available The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax and rate of force development over 100ms (RFD100, countermovement jump (CMJ and squat jump (SJ height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg were divided into experimental (EXP; n = 36 and control (CON, n = 32 groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions. Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, p<0.001, and from mid- to post-training (Δ ~4%, p < 0.001 in EXP were observed. In CON significantly enhanced Fmax from pre- to mid-training (Δ ~3.5%, p < 0.05 was recorded, but no other significant changes were observed in any other test. In RFD100 significant improvements from pre- to mid-training (Δ ~27%, p < 0.001, as well as from mid- to post-training (Δ ~17%, p < 0.01 were observed. CMJ and SJ height were significantly enhanced from pre- to mid-training (Δ ~10%, ~15%, respectively, p < 0.001 but no further changes occurred from mid- to post-training. Significant improvements in 50 m sprint time from pre- to mid-training (Δ -1%, p < 0.05, and from mid- to post-training (Δ -1.9%, p < 0.001 in EXP were observed. Furthermore, percent changes in EXP were greater than changes in CON during training. It appears that using jump squats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term.

  9. Self-mode-locking operation of a diode-end-pumped Tm:YAP laser with watt-level output power

    Science.gov (United States)

    Zhang, Su; Zhang, Xinlu; Huang, Jinjer; Wang, Tianhan; Dai, Junfeng; Dong, Guangzong

    2018-03-01

    We report on a high power continuous wave (CW) self-mode-locked Tm:YAP laser pumped by a 792 nm laser diode. Without any additional mode-locking elements in the cavity, stable and self-starting mode-locking operation has been realized. The threshold pump power of the CW self-mode-locked Tm:YAP laser is only 5.4 W. The maximum average output power is as high as 1.65 W at the pump power of 12 W, with the repetition frequency of 468 MHz and the center wavelength of 1943 nm. To the best of our knowledge, this is the first CW self-mode-locked Tm:YAP laser. The experiment results show that the Tm:YAP crystal is a promising gain medium for realizing the high power self-mode-locking operation at 2 µm.

  10. Bibliometrics analysis of publication output in library and information ...

    African Journals Online (AJOL)

    The Web of Science was used as indexing/citation database in the study. The findings of the study revealed increasing trend in annual publication output in LIS research in Nigerian universities which indicates that there is progress in the development of LIS research in Nigeria. It was found that, typically and on the average, ...

  11. Efficient processing of CFRP with a picosecond laser with up to 1.4 kW average power

    Science.gov (United States)

    Onuseit, V.; Freitag, C.; Wiedenmann, M.; Weber, R.; Negel, J.-P.; Löscher, A.; Abdou Ahmed, M.; Graf, T.

    2015-03-01

    Laser processing of carbon fiber reinforce plastic (CFRP) is a very promising method to solve a lot of the challenges for large-volume production of lightweight constructions in automotive and airplane industries. However, the laser process is actual limited by two main issues. First the quality might be reduced due to thermal damage and second the high process energy needed for sublimation of the carbon fibers requires laser sources with high average power for productive processing. To achieve thermal damage of the CFRP of less than 10μm intensities above 108 W/cm² are needed. To reach these high intensities in the processing area ultra-short pulse laser systems are favored. Unfortunately the average power of commercially available laser systems is up to now in the range of several tens to a few hundred Watt. To sublimate the carbon fibers a large volume specific enthalpy of 85 J/mm³ is necessary. This means for example that cutting of 2 mm thick material with a kerf width of 0.2 mm with industry-typical 100 mm/sec requires several kilowatts of average power. At the IFSW a thin-disk multipass amplifier yielding a maximum average output power of 1100 W (300 kHz, 8 ps, 3.7 mJ) allowed for the first time to process CFRP at this average power and pulse energy level with picosecond pulse duration. With this unique laser system cutting of CFRP with a thickness of 2 mm an effective average cutting speed of 150 mm/sec with a thermal damage below 10μm was demonstrated.

  12. Bayesian Model Averaging of Artificial Intelligence Models for Hydraulic Conductivity Estimation

    Science.gov (United States)

    Nadiri, A.; Chitsazan, N.; Tsai, F. T.; Asghari Moghaddam, A.

    2012-12-01

    This research presents a Bayesian artificial intelligence model averaging (BAIMA) method that incorporates multiple artificial intelligence (AI) models to estimate hydraulic conductivity and evaluate estimation uncertainties. Uncertainty in the AI model outputs stems from error in model input as well as non-uniqueness in selecting different AI methods. Using one single AI model tends to bias the estimation and underestimate uncertainty. BAIMA employs Bayesian model averaging (BMA) technique to address the issue of using one single AI model for estimation. BAIMA estimates hydraulic conductivity by averaging the outputs of AI models according to their model weights. In this study, the model weights were determined using the Bayesian information criterion (BIC) that follows the parsimony principle. BAIMA calculates the within-model variances to account for uncertainty propagation from input data to AI model output. Between-model variances are evaluated to account for uncertainty due to model non-uniqueness. We employed Takagi-Sugeno fuzzy logic (TS-FL), artificial neural network (ANN) and neurofuzzy (NF) to estimate hydraulic conductivity for the Tasuj plain aquifer, Iran. BAIMA combined three AI models and produced better fitting than individual models. While NF was expected to be the best AI model owing to its utilization of both TS-FL and ANN models, the NF model is nearly discarded by the parsimony principle. The TS-FL model and the ANN model showed equal importance although their hydraulic conductivity estimates were quite different. This resulted in significant between-model variances that are normally ignored by using one AI model.

  13. Utilizing Maximum Power Point Trackers in Parallel to Maximize the Power Output of a Solar (Photovoltaic) Array

    Science.gov (United States)

    2012-12-01

    completing the academic workload at NPS. Taking care of two toddlers all day, every day, is not an easy task. You make xxviii it seem effortless and...for the development of numerous thin-cell applications that meet the military’s requirements for ruggedness and power output. For example, the...2012, September 5). PV microinverters and power optimizers set for significant growth [PV Magazine Online]. Available: http://www.pv- magazine.com

  14. Prescriptive amplification recommendations for hearing losses with a conductive component and their impact on the required maximum power output: an update with accompanying clinical explanation.

    Science.gov (United States)

    Johnson, Earl E

    2013-06-01

    Hearing aid prescriptive recommendations for hearing losses having a conductive component have received less clinical and research interest than for losses of a sensorineural nature; as a result, much variation remains among current prescriptive methods in their recommendations for conductive and mixed hearing losses (Johnson and Dillon, 2011). The primary intent of this brief clinical note is to demonstrate differences between two algebraically equivalent expressions of hearing loss, which have been approaches used historically to generate a prescription for hearing losses with a conductive component. When air and bone conduction thresholds are entered into hearing aid prescriptions designed for nonlinear hearing aids, it was hypothesized that that two expressions would not yield equivalent amounts of prescribed insertion gain and output. These differences are examined for their impact on the maximum power output (MPO) requirements of the hearing aid. Subsequently, the MPO capabilities of two common behind-the-ear (BTE) receiver placement alternatives, receiver-in-aid (RIA) and receiver-in-canal (RIC), are examined. The two expressions of hearing losses examined were the 25% ABG + AC approach and the 75% ABG + BC approach, where ABG refers to air-bone gap, AC refers to air-conduction threshold, and BC refers to bone-conduction threshold. Example hearing loss cases with a conductive component are sampled for calculations. The MPO capabilities of the BTE receiver placements in commercially-available products were obtained from hearing aids on the U.S. federal purchasing contract. Prescribed gain and the required MPO differs markedly between the two approaches. The 75% ABG + BC approach prescribes a compression ratio that is reflective of the amount of sensorineural hearing loss. Not all hearing aids will have the MPO capabilities to support the output requirements for fitting hearing losses with a large conductive component particularly when combined with

  15. Configuration of LWR fuel enrichment or burnup yielding maximum power

    International Nuclear Information System (INIS)

    Bartosek, V.; Zalesky, K.

    1976-01-01

    An analysis is given of the spatial distribution of fuel burnup and enrichment in a light-water lattice of given dimensions with slightly enriched uranium, at which the maximum output is achieved. It is based on the spatial solution of neutron flux using a one-group diffusion model in which linear dependence may be expected of the fission cross section and the material buckling parameter on the fuel burnup and enrichment. Two problem constraints are considered, i.e., the neutron flux value and the specific output value. For the former the optimum core configuration remains qualitatively unchanged for any reflector thickness, for the latter the cases of a reactor with and without reflector must be distinguished. (Z.M.)

  16. Pareto Principle in Datamining: an Above-Average Fencing Algorithm

    Directory of Open Access Journals (Sweden)

    K. Macek

    2008-01-01

    Full Text Available This paper formulates a new datamining problem: which subset of input space has the relatively highest output where the minimal size of this subset is given. This can be useful where usual datamining methods fail because of error distribution asymmetry. The paper provides a novel algorithm for this datamining problem, and compares it with clustering of above-average individuals.

  17. Modelling and Prediction of Photovoltaic Power Output Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Aminmohammad Saberian

    2014-01-01

    Full Text Available This paper presents a solar power modelling method using artificial neural networks (ANNs. Two neural network structures, namely, general regression neural network (GRNN feedforward back propagation (FFBP, have been used to model a photovoltaic panel output power and approximate the generated power. Both neural networks have four inputs and one output. The inputs are maximum temperature, minimum temperature, mean temperature, and irradiance; the output is the power. The data used in this paper started from January 1, 2006, until December 31, 2010. The five years of data were split into two parts: 2006–2008 and 2009-2010; the first part was used for training and the second part was used for testing the neural networks. A mathematical equation is used to estimate the generated power. At the end, both of these networks have shown good modelling performance; however, FFBP has shown a better performance comparing with GRNN.

  18. Measuring power output intermittency and unsteady loading in a micro wind farm model

    OpenAIRE

    Bossuyt, Juliaan; Howland, Michael; Meneveau, Charles; Meyers, Johan

    2016-01-01

    In this study porous disc models are used as a turbine model for a wind-tunnel wind farm experiment, allowing the measurement of the power output, thrust force and spatially averaged incoming velocity for every turbine. The model's capabilities for studying the unsteady turbine loading, wind farm power output intermittency and spatio temporal correlations between wind turbines are demonstrated on an aligned wind farm, consisting of 100 wind turbine models.

  19. Reproducing multi-model ensemble average with Ensemble-averaged Reconstructed Forcings (ERF) in regional climate modeling

    Science.gov (United States)

    Erfanian, A.; Fomenko, L.; Wang, G.

    2016-12-01

    Multi-model ensemble (MME) average is considered the most reliable for simulating both present-day and future climates. It has been a primary reference for making conclusions in major coordinated studies i.e. IPCC Assessment Reports and CORDEX. The biases of individual models cancel out each other in MME average, enabling the ensemble mean to outperform individual members in simulating the mean climate. This enhancement however comes with tremendous computational cost, which is especially inhibiting for regional climate modeling as model uncertainties can originate from both RCMs and the driving GCMs. Here we propose the Ensemble-based Reconstructed Forcings (ERF) approach to regional climate modeling that achieves a similar level of bias reduction at a fraction of cost compared with the conventional MME approach. The new method constructs a single set of initial and boundary conditions (IBCs) by averaging the IBCs of multiple GCMs, and drives the RCM with this ensemble average of IBCs to conduct a single run. Using a regional climate model (RegCM4.3.4-CLM4.5), we tested the method over West Africa for multiple combination of (up to six) GCMs. Our results indicate that the performance of the ERF method is comparable to that of the MME average in simulating the mean climate. The bias reduction seen in ERF simulations is achieved by using more realistic IBCs in solving the system of equations underlying the RCM physics and dynamics. This endows the new method with a theoretical advantage in addition to reducing computational cost. The ERF output is an unaltered solution of the RCM as opposed to a climate state that might not be physically plausible due to the averaging of multiple solutions with the conventional MME approach. The ERF approach should be considered for use in major international efforts such as CORDEX. Key words: Multi-model ensemble, ensemble analysis, ERF, regional climate modeling

  20. Development of Compact Ozonizer with High Ozone Output by Pulsed Power

    Science.gov (United States)

    Tanaka, Fumiaki; Ueda, Satoru; Kouno, Kanako; Sakugawa, Takashi; Akiyama, Hidenori; Kinoshita, Youhei

    Conventional ozonizer with a high ozone output using silent or surface discharges needs a cooling system and a dielectric barrier, and therefore becomes a large machine. A compact ozonizer without the cooling system and the dielectric barrier has been developed by using a pulsed power generated discharge. The wire to plane electrodes made of metal have been used. However, the ozone output was low. Here, a compact and high repetition rate pulsed power generator is used as an electric source of a compact ozonizer. The ozone output of 6.1 g/h and the ozone yield of 86 g/kWh are achieved at 500 pulses per second, input average power of 280 W and an air flow rate of 20 L/min.

  1. Maximum Power Point Tracking in Variable Speed Wind Turbine Based on Permanent Magnet Synchronous Generator Using Maximum Torque Sliding Mode Control Strategy

    Institute of Scientific and Technical Information of China (English)

    Esmaeil Ghaderi; Hossein Tohidi; Behnam Khosrozadeh

    2017-01-01

    The present study was carried out in order to track the maximum power point in a variable speed turbine by minimizing electromechanical torque changes using a sliding mode control strategy.In this strategy,fhst,the rotor speed is set at an optimal point for different wind speeds.As a result of which,the tip speed ratio reaches an optimal point,mechanical power coefficient is maximized,and wind turbine produces its maximum power and mechanical torque.Then,the maximum mechanical torque is tracked using electromechanical torque.In this technique,tracking error integral of maximum mechanical torque,the error,and the derivative of error are used as state variables.During changes in wind speed,sliding mode control is designed to absorb the maximum energy from the wind and minimize the response time of maximum power point tracking (MPPT).In this method,the actual control input signal is formed from a second order integral operation of the original sliding mode control input signal.The result of the second order integral in this model includes control signal integrity,full chattering attenuation,and prevention from large fluctuations in the power generator output.The simulation results,calculated by using MATLAB/m-file software,have shown the effectiveness of the proposed control strategy for wind energy systems based on the permanent magnet synchronous generator (PMSG).

  2. Evaluation of Navigation System Accuracy Indexes for Deviation Reading from Average Range

    Directory of Open Access Journals (Sweden)

    Alexey Boykov

    2017-12-01

    Full Text Available The method for estimating the mean of square error, kurtosis and error correlation coefficient for deviations from the average range of three navigation parameter indications from the outputs of three information sensors is substantiated and developed.

  3. Comparison of Extremum-Seeking Control Techniques for Maximum Power Point Tracking in Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Chen-Han Wu

    2011-12-01

    Full Text Available Due to Japan’s recent nuclear crisis and petroleum price hikes, the search for renewable energy sources has become an issue of immediate concern. A promising candidate attracting much global attention is solar energy, as it is green and also inexhaustible. A maximum power point tracking (MPPT controller is employed in such a way that the output power provided by a photovoltaic (PV system is boosted to its maximum level. However, in the context of abrupt changes in irradiance, conventional MPPT controller approaches suffer from insufficient robustness against ambient variation, inferior transient response and a loss of output power as a consequence of the long duration required of tracking procedures. Accordingly, in this work the maximum power point tracking is carried out successfully using a sliding mode extremum-seeking control (SMESC method, and the tracking performances of three controllers are compared by simulations, that is, an extremum-seeking controller, a sinusoidal extremum-seeking controller and a sliding mode extremum-seeking controller. Being able to track the maximum power point promptly in the case of an abrupt change in irradiance, the SMESC approach is proven by simulations to be superior in terms of system dynamic and steady state responses, and an excellent robustness along with system stability is demonstrated as well.

  4. The moving-window Bayesian maximum entropy framework: estimation of PM(2.5) yearly average concentration across the contiguous United States.

    Science.gov (United States)

    Akita, Yasuyuki; Chen, Jiu-Chiuan; Serre, Marc L

    2012-09-01

    Geostatistical methods are widely used in estimating long-term exposures for epidemiological studies on air pollution, despite their limited capabilities to handle spatial non-stationarity over large geographic domains and the uncertainty associated with missing monitoring data. We developed a moving-window (MW) Bayesian maximum entropy (BME) method and applied this framework to estimate fine particulate matter (PM(2.5)) yearly average concentrations over the contiguous US. The MW approach accounts for the spatial non-stationarity, while the BME method rigorously processes the uncertainty associated with data missingness in the air-monitoring system. In the cross-validation analyses conducted on a set of randomly selected complete PM(2.5) data in 2003 and on simulated data with different degrees of missing data, we demonstrate that the MW approach alone leads to at least 17.8% reduction in mean square error (MSE) in estimating the yearly PM(2.5). Moreover, the MWBME method further reduces the MSE by 8.4-43.7%, with the proportion of incomplete data increased from 18.3% to 82.0%. The MWBME approach leads to significant reductions in estimation error and thus is recommended for epidemiological studies investigating the effect of long-term exposure to PM(2.5) across large geographical domains with expected spatial non-stationarity.

  5. The moving-window Bayesian Maximum Entropy framework: Estimation of PM2.5 yearly average concentration across the contiguous United States

    Science.gov (United States)

    Akita, Yasuyuki; Chen, Jiu-Chiuan; Serre, Marc L.

    2013-01-01

    Geostatistical methods are widely used in estimating long-term exposures for air pollution epidemiological studies, despite their limited capabilities to handle spatial non-stationarity over large geographic domains and uncertainty associated with missing monitoring data. We developed a moving-window (MW) Bayesian Maximum Entropy (BME) method and applied this framework to estimate fine particulate matter (PM2.5) yearly average concentrations over the contiguous U.S. The MW approach accounts for the spatial non-stationarity, while the BME method rigorously processes the uncertainty associated with data missingnees in the air monitoring system. In the cross-validation analyses conducted on a set of randomly selected complete PM2.5 data in 2003 and on simulated data with different degrees of missing data, we demonstrate that the MW approach alone leads to at least 17.8% reduction in mean square error (MSE) in estimating the yearly PM2.5. Moreover, the MWBME method further reduces the MSE by 8.4% to 43.7% with the proportion of incomplete data increased from 18.3% to 82.0%. The MWBME approach leads to significant reductions in estimation error and thus is recommended for epidemiological studies investigating the effect of long-term exposure to PM2.5 across large geographical domains with expected spatial non-stationarity. PMID:22739679

  6. Comparison of bile acid synthesis determined by isotope dilution versus fecal acidic sterol output in human subjects

    International Nuclear Information System (INIS)

    Duane, W.C.; Holloway, D.E.; Hutton, S.W.; Corcoran, P.J.; Haas, N.A.

    1982-01-01

    Fecal acidic sterol output has been found to be much lower than bile acid synthesis determined by isotope dilution. Because of this confusing discrepancy, we compared these 2 measurements done simultaneously on 13 occasions in 5 normal volunteers. In contrast to previous findings, bile acid synthesis by the Lindstedt isotope dilution method averaged 16.3% lower than synthesis simultaneously determined by fecal acidic sterol output (95% confidence limit for the difference - 22.2 to -10.4%). When one-sample determinations of bile acid pools were substituted for Lindstedt pools, bile acid synthesis by isotope dilution averaged 5.6% higher than synthesis by fecal acidic sterol output (95% confidence limits -4.9 to 16.1%). These data indicate that the 2 methods yield values in reasonably close agreement with one another. If anything, fecal acidic sterol outputs are slightly higher than synthesis by isotope dilution

  7. A Single Phase Doubly Grounded Semi-Z-Source Inverter for Photovoltaic (PV Systems with Maximum Power Point Tracking (MPPT

    Directory of Open Access Journals (Sweden)

    Tofael Ahmed

    2014-06-01

    Full Text Available In this paper, a single phase doubly grounded semi-Z-source inverter with maximum power point tracking (MPPT is proposed for photovoltaic (PV systems. This proposed system utilizes a single-ended primary inductor (SEPIC converter as DC-DC converter to implement the MPPT algorithm for tracking the maximum power from a PV array and a single phase semi-Z-source inverter for integrating the PV with AC power utilities. The MPPT controller utilizes a fast-converging algorithm to track the maximum power point (MPP and the semi-Z-source inverter utilizes a nonlinear SPWM to produce sinusoidal voltage at the output. The proposed system is able to track the MPP of PV arrays and produce an AC voltage at its output by utilizing only three switches. Experimental results show that the fast-converging MPPT algorithm has fast tracking response with appreciable MPP efficiency. In addition, the inverter shows the minimization of common mode leakage current with its ground sharing feature and reduction of the THD as well as DC current components at the output during DC-AC conversion.

  8. A Comparative Frequency Analysis of Maximum Daily Rainfall for a SE Asian Region under Current and Future Climate Conditions

    Directory of Open Access Journals (Sweden)

    Velautham Daksiya

    2017-01-01

    Full Text Available The impact of changing climate on the frequency of daily rainfall extremes in Jakarta, Indonesia, is analysed and quantified. The study used three different models to assess the changes in rainfall characteristics. The first method involves the use of the weather generator LARS-WG to quantify changes between historical and future daily rainfall maxima. The second approach consists of statistically downscaling general circulation model (GCM output based on historical empirical relationships between GCM output and station rainfall. Lastly, the study employed recent statistically downscaled global gridded rainfall projections to characterize climate change impact rainfall structure. Both annual and seasonal rainfall extremes are studied. The results show significant changes in annual maximum daily rainfall, with an average increase as high as 20% in the 100-year return period daily rainfall. The uncertainty arising from the use of different GCMs was found to be much larger than the uncertainty from the emission scenarios. Furthermore, the annual and wet seasonal analyses exhibit similar behaviors with increased future rainfall, but the dry season is not consistent across the models. The GCM uncertainty is larger in the dry season compared to annual and wet season.

  9. Effect of PV module output power on module temperature; Taiyo denchi no shutsuryoku henka ga module hyomen ondo ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Hongo, T; Kitamura, A [Kansai Electric Power Co. Inc., Osaka (Japan); Igaki, K; Mizumoto, T [Kanden Kako Co. Inc., Osaka (Japan)

    1996-10-27

    Effect of the photovoltaic (PV) module output power variation on the module surface temperature has been investigated by field measurements. PV modules with capacity of 54 W were used for the temperature measurements. Three 2 kW-class PV systems were operated. T-type thermocouples were used for measuring temperatures. Measurement time intervals were 15 minutes, 30 minutes, 60 minutes, and 24 hours. Measurement period was between May 25, 1995 and June 25, 1996. The surface temperature increased during non-loaded PV output, and decreased during load-carrying PV output. Difference of the surface temperature between non-loaded PV output and load-carrying PV output was 3.5{degree}C at maximum through a year. The surface temperature was saturated within 30 minutes. When PV output was changed in 30 or 60 minutes interval, the variation of surface temperature was distinctly observed. When PV output was changed in 15 minutes interval, it was not observed distinctly. There was no difference of the surface temperatures during the time zones with less solar radiation, such as in the morning and evening, and at night. Except these time zones, difference of the surface temperatures was 3.5{degree}C at maximum. 4 figs.

  10. Maximum time-dependent space-charge limited diode currents

    Energy Technology Data Exchange (ETDEWEB)

    Griswold, M. E. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Fisch, N. J. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

    2016-01-15

    Recent papers claim that a one dimensional (1D) diode with a time-varying voltage drop can transmit current densities that exceed the Child-Langmuir (CL) limit on average, apparently contradicting a previous conjecture that there is a hard limit on the average current density across any 1D diode, as t → ∞, that is equal to the CL limit. However, these claims rest on a different definition of the CL limit, namely, a comparison between the time-averaged diode current and the adiabatic average of the expression for the stationary CL limit. If the current were considered as a function of the maximum applied voltage, rather than the average applied voltage, then the original conjecture would not have been refuted.

  11. Implementation of bayesian model averaging on the weather data forecasting applications utilizing open weather map

    Science.gov (United States)

    Rahmat, R. F.; Nasution, F. R.; Seniman; Syahputra, M. F.; Sitompul, O. S.

    2018-02-01

    Weather is condition of air in a certain region at a relatively short period of time, measured with various parameters such as; temperature, air preasure, wind velocity, humidity and another phenomenons in the atmosphere. In fact, extreme weather due to global warming would lead to drought, flood, hurricane and other forms of weather occasion, which directly affects social andeconomic activities. Hence, a forecasting technique is to predict weather with distinctive output, particullary mapping process based on GIS with information about current weather status in certain cordinates of each region with capability to forecast for seven days afterward. Data used in this research are retrieved in real time from the server openweathermap and BMKG. In order to obtain a low error rate and high accuracy of forecasting, the authors use Bayesian Model Averaging (BMA) method. The result shows that the BMA method has good accuracy. Forecasting error value is calculated by mean square error shows (MSE). The error value emerges at minumum temperature rated at 0.28 and maximum temperature rated at 0.15. Meanwhile, the error value of minimum humidity rates at 0.38 and the error value of maximum humidity rates at 0.04. Afterall, the forecasting error rate of wind speed is at 0.076. The lower the forecasting error rate, the more optimized the accuracy is.

  12. Influence of deleting some of the inputs and outputs on efficiency status of units in DEA

    Directory of Open Access Journals (Sweden)

    Abbas ali Noora

    2013-06-01

    Full Text Available One of the important issues in data envelopment analysis (DEA is sensitivity analysis. This study discusses about deleting some of the inputs and outputs and investigates the influence of it on efficiency status of Decision Making Units (DMUs. To this end some models are presented for recognizing this influence on efficient DMUs. Model 2 (Model 3 in section 3 investigates the influence of deleting i(th input (r(th output on an efficient DMU. Thereafter these models are improved for deleting multiple inputs and outputs. Furthermore, a model is presented for recognizing the maximum number of inputs and (or outputs from among specified inputs and outputs which can be deleted, whereas an efficient DMU preserves its efficiency. Finally, the presented models are utilized for a set of DMUs and the results are reported.

  13. Hybrid Solid Oxide Fuel Cell and Thermoelectric Generator for Maximum Power Output in Micro-CHP Systems

    DEFF Research Database (Denmark)

    Rosendahl, Lasse; Mortensen, Paw Vestergård; Enkeshafi, Ali A.

    2011-01-01

    and market segments which are not yet quantified. This paper quantifies a micro-CHP system based on a solid oxide fuel cell (SOFC) and a high-performance TE generator. Based on a 3 kW fuel input, the hybrid SOFC implementation boosts electrical output from 945 W to 1085 W, with 1794 W available for heating...... the electricity production in micro-CHP systems by more than 15%, corresponding to system electrical efficiency increases of some 4 to 5 percentage points. This will make fuel cell-based micro-CHP systems very competitive and profitable and will also open opportunities in a number of other potential business...

  14. Survey of the variation in ultraviolet outputs from ultraviolet A sunbeds in Bradford.

    Science.gov (United States)

    Wright, A L; Hart, G C; Kernohan, E; Twentyman, G

    1996-02-01

    Concerns have been expressed for some time regarding the growth of the cosmetic suntanning industry and the potential harmful effects resulting from these exposures. Recently published work has appeared to confirm a link between sunbed use and skin cancer. A previous survey in Oxford some years ago demonstrated significant output variations, and we have attempted to extend and update that work. Ultraviolet A, UVB and blue-light output measurements were made on 50 sunbeds using a radiometer fitted with broad-band filters and detectors. A number of irradiance measurements were made on each sunbed within each waveband so that the uniformity of the output could also be assessed. UVA outputs varied by a factor of 3, with a mean of 13.5 mW/cm2; UVB outputs varied by a factor of 60, with a mean of 19.2 microW/cm2; and blue-light outputs varied by a factor of 2.5, with a mean of 2.5 mW/cm2. Outputs fall on average to 80% of the central value at either end of the sunbed. Facial units in sunbeds ranged in output between 18 and 45 mW/cm2. Output uniformity shows wide variation, with 16% of the sunbeds having an axial coefficient of variation > 10%. UVB output is highly tube-specific. Eyewear used in sunbeds should also protect against blue light.

  15. Characteristic analysis of a polarization output coupling Porro prism resonator

    Science.gov (United States)

    Yang, Hailong; Meng, Junqing; Chen, Weibiao

    2015-02-01

    An Electro-optical Q-switched Nd:YAG slab laser with a crossed misalignment Porro prism resonator for space applications has been theoretically and experimentally investigated. The phase shift induced by the combination of different wave plates and Porro prism azimuth angles have been studied for creating high loss condition prior to Q-switching. The relationship of the effective output coupling reflectivity and the employed Q-switch driving voltage is explored by using Jones matrix optics. In the experiment, the maximum output pulse energy of 93 mJ with 14-ns pulse duration is obtained at the repetition rate of 20 Hz and the optical-to-optical conversion efficiency is 16.8%. The beam quality factors are M 2 x = 2.5 and M 2y = 2.2, respectively.

  16. Optimum detection for extracting maximum information from symmetric qubit sets

    International Nuclear Information System (INIS)

    Mizuno, Jun; Fujiwara, Mikio; Sasaki, Masahide; Akiba, Makoto; Kawanishi, Tetsuya; Barnett, Stephen M.

    2002-01-01

    We demonstrate a class of optimum detection strategies for extracting the maximum information from sets of equiprobable real symmetric qubit states of a single photon. These optimum strategies have been predicted by Sasaki et al. [Phys. Rev. A 59, 3325 (1999)]. The peculiar aspect is that the detections with at least three outputs suffice for optimum extraction of information regardless of the number of signal elements. The cases of ternary (or trine), quinary, and septenary polarization signals are studied where a standard von Neumann detection (a projection onto a binary orthogonal basis) fails to access the maximum information. Our experiments demonstrate that it is possible with present technologies to attain about 96% of the theoretical limit

  17. LCLS Maximum Credible Beam Power

    International Nuclear Information System (INIS)

    Clendenin, J.

    2005-01-01

    The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

  18. High average power 1314 nm Nd:YLF laser, passively Q-switched with V:YAG

    CSIR Research Space (South Africa)

    Botha, RC

    2013-03-01

    Full Text Available A 1314 nm Nd:YLF laser was designed and operated both CW and passively Q-switched. Maximum CW output of 10.4 W resulted from 45.2 Wof incident pump power. Passive Q-switching was obtained by inserting a V:YAG saturable absorber in the cavity...

  19. Parametric characteristics of a solar thermophotovoltaic system at the maximum efficiency

    International Nuclear Information System (INIS)

    Liao, Tianjun; Chen, Xiaohang; Yang, Zhimin; Lin, Bihong; Chen, Jincan

    2016-01-01

    Graphical abstract: A model of the far-field TPVC driven by solar energy, which consists of an optical concentrator, an absorber, an emitter, and a PV cell and is simply referred as to the far-field STPVS. - Highlights: • A model of the far-field solar thermophotovoltaic system (STPVS) is established. • External and internal irreversible losses are considered. • The maximum efficiency of the STPVS is calculated. • Optimal values of key parameters at the maximum efficiency are determined. • Effects of the concentrator factor on the performance of the system are discussed. - Abstract: A model of the solar thermophotovoltaic system (STPVS) consisting of an optical concentrator, a thermal absorber, an emitter, and a photovoltaic (PV) cell is proposed, where the far-field thermal emission between the emitter and the PV cell, the radiation losses from the absorber and emitter to the environment, the reflected loss from the absorber, and the finite-rate heat exchange between the PV cell and the environment are taken into account. Analytical expressions for the power output of and overall efficiency of the STPVS are derived. By solving thermal equilibrium equations, the operating temperatures of the emitter and PV cell are determined and the maximum efficiency of the system is calculated numerically for given values of the output voltage of the PV cell and the ratio of the front surface area of the absorber to that of the emitter. For different bandgaps, the maximum efficiencies of the system are calculated and the corresponding optimum values of several operating parameters are obtained. The effects of the concentrator factor on the optimum performance of the system are also discussed.

  20. World crude output overcomes Persian Gulf disruption

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Several OPEC producers made good on their promises to replace 2.7 MMbpd of oil exports that vanished from the world market after Iraq took over Kuwait. Even more incredibly, they accomplished this while a breathtaking 1.2- MMbopd reduction in Soviet output took place during the course of 1991. After Abu Dhabi, Indonesia, Iran, Libya, Nigeria, Saudi Arabia and Venezuela turned the taps wide open, their combined output rose 2.95 MMbopd. Put together with a 282,000-bopd increase by Norway and contributions from smaller producers, this enabled world oil production to remain within 400,000 bopd of its 1990 level. The 60.5-MMbopd average was off by just 0.7%. This paper reports that improvement took place in five of eight regions. Largest increases were in Western Europe and Africa. Greatest reductions occurred in Eastern Europe and the Middle East. Fifteen nations produced 1 MMbopd or more last year, compared with 17 during 1990

  1. Epilepsy Research in Iran: a Scientometric Analysis of Publications Output During 2000-2014.

    Science.gov (United States)

    Rasolabadi, Masoud; Rasouli-Ghahfarkhi, Seyedeh Moloud; Ardalan, Marlin; Kalhor, Marya Maryam; Seidi, Jamal; Gharib, Alireza

    2015-12-01

    The aim of this study is to analyze the epilepsy research output of Iran in national and global contexts, as reflected in its publication output indexed in Scopus citation database during 2000-2014. This study was based on the publications of epilepsy research from Iranian authors retrieved Feb. 2015 from Scopus Citation database [www.scopus.com]. The string used to retrieve the data was developed using "epilepsy OR epilepsies" keywords in title, abstract and keywords and Iran in affiliation field was our main string. Cumulative publication output of Iran in epilepsy research consisted of 702 papers from 2000 to 2014, with an average number of 46.53 papers per year. The total publication output of Iran in epilepsy research increased from 2 papers in 2000 to 88 papers in 2014. Hence, with 702 paper, Iran ranked 25(th) among the top 25 countries with a global share of 0.82 %. Iranian publication average citation per paper increased from 0 in 2000 to 7.88 in 2014. Overall, the received citations were 3184 citations during those years. Iran is collaborating with 36 countries with no more than 244 of its papers (35% of its total papers). It is necessary to prepare conditions for epilepsy researchers to collaborate more with international scientific societies in order to produce more and high quality papers.

  2. Evaluation of a photovoltaic energy mechatronics system with a built-in quadratic maximum power point tracking algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Chao, R.M.; Ko, S.H.; Lin, I.H. [Department of Systems and Naval Mechatronics Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China); Pai, F.S. [Department of Electronic Engineering, National University of Tainan (China); Chang, C.C. [Department of Environment and Energy, National University of Tainan (China)

    2009-12-15

    The historically high cost of crude oil price is stimulating research into solar (green) energy as an alternative energy source. In general, applications with large solar energy output require a maximum power point tracking (MPPT) algorithm to optimize the power generated by the photovoltaic effect. This work aims to provide a stand-alone solution for solar energy applications by integrating a DC/DC buck converter to a newly developed quadratic MPPT algorithm along with its appropriate software and hardware. The quadratic MPPT method utilizes three previously used duty cycles with their corresponding power outputs. It approaches the maximum value by using a second order polynomial formula, which converges faster than the existing MPPT algorithm. The hardware implementation takes advantage of the real-time controller system from National Instruments, USA. Experimental results have shown that the proposed solar mechatronics system can correctly and effectively track the maximum power point without any difficulties. (author)

  3. Output control of da Vinci surgical system's surgical graspers.

    Science.gov (United States)

    Johnson, Paul J; Schmidt, David E; Duvvuri, Umamaheswar

    2014-01-01

    The number of robot-assisted surgeries performed with the da Vinci surgical system has increased significantly over the past decade. The articulating movements of the robotic surgical grasper are controlled by grip controls at the master console. The user interface has been implicated as one contributing factor in surgical grasping errors. The goal of our study was to characterize and evaluate the user interface of the da Vinci surgical system in controlling surgical graspers. An angular manipulator with force sensors was used to increment the grip control angle as grasper output angles were measured. Input force at the grip control was simultaneously measured throughout the range of motion. Pressure film was used to assess the maximum grasping force achievable with the endoscopic grasping tool. The da Vinci robot's grip control angular input has a nonproportional relationship with the grasper instrument output. The grip control mechanism presents an intrinsic resistant force to the surgeon's fingertips and provides no haptic feedback. The da Vinci Maryland graspers are capable of applying up to 5.1 MPa of local pressure. The angular and force input at the grip control of the da Vinci robot's surgical graspers is nonproportional to the grasper instrument's output. Understanding the true relationship of the grip control input to grasper instrument output may help surgeons understand how to better control the surgical graspers and promote fewer grasping errors. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Sub-100 fs high average power directly blue-diode-laser-pumped Ti:sapphire oscillator

    Science.gov (United States)

    Rohrbacher, Andreas; Markovic, Vesna; Pallmann, Wolfgang; Resan, Bojan

    2016-03-01

    Ti:sapphire oscillators are a proven technology to generate sub-100 fs (even sub-10 fs) pulses in the near infrared and are widely used in many high impact scientific fields. However, the need for a bulky, expensive and complex pump source, typically a frequency-doubled multi-watt neodymium or optically pumped semiconductor laser, represents the main obstacle to more widespread use. The recent development of blue diodes emitting over 1 W has opened up the possibility of directly diode-laser-pumped Ti:sapphire oscillators. Beside the lower cost and footprint, a direct diode pumping provides better reliability, higher efficiency and better pointing stability to name a few. The challenges that it poses are lower absorption of Ti:sapphire at available diode wavelengths and lower brightness compared to typical green pump lasers. For practical applications such as bio-medicine and nano-structuring, output powers in excess of 100 mW and sub-100 fs pulses are required. In this paper, we demonstrate a high average power directly blue-diode-laser-pumped Ti:sapphire oscillator without active cooling. The SESAM modelocking ensures reliable self-starting and robust operation. We will present two configurations emitting 460 mW in 82 fs pulses and 350 mW in 65 fs pulses, both operating at 92 MHz. The maximum obtained pulse energy reaches 5 nJ. A double-sided pumping scheme with two high power blue diode lasers was used for the output power scaling. The cavity design and the experimental results will be discussed in more details.

  5. Novel maximum-margin training algorithms for supervised neural networks.

    Science.gov (United States)

    Ludwig, Oswaldo; Nunes, Urbano

    2010-06-01

    This paper proposes three novel training methods, two of them based on the backpropagation approach and a third one based on information theory for multilayer perceptron (MLP) binary classifiers. Both backpropagation methods are based on the maximal-margin (MM) principle. The first one, based on the gradient descent with adaptive learning rate algorithm (GDX) and named maximum-margin GDX (MMGDX), directly increases the margin of the MLP output-layer hyperplane. The proposed method jointly optimizes both MLP layers in a single process, backpropagating the gradient of an MM-based objective function, through the output and hidden layers, in order to create a hidden-layer space that enables a higher margin for the output-layer hyperplane, avoiding the testing of many arbitrary kernels, as occurs in case of support vector machine (SVM) training. The proposed MM-based objective function aims to stretch out the margin to its limit. An objective function based on Lp-norm is also proposed in order to take into account the idea of support vectors, however, overcoming the complexity involved in solving a constrained optimization problem, usually in SVM training. In fact, all the training methods proposed in this paper have time and space complexities O(N) while usual SVM training methods have time complexity O(N (3)) and space complexity O(N (2)) , where N is the training-data-set size. The second approach, named minimization of interclass interference (MICI), has an objective function inspired on the Fisher discriminant analysis. Such algorithm aims to create an MLP hidden output where the patterns have a desirable statistical distribution. In both training methods, the maximum area under ROC curve (AUC) is applied as stop criterion. The third approach offers a robust training framework able to take the best of each proposed training method. The main idea is to compose a neural model by using neurons extracted from three other neural networks, each one previously trained by

  6. Maximization of energy in the output of a linear system

    International Nuclear Information System (INIS)

    Dudley, D.G.

    1976-01-01

    A time-limited signal which, when passed through a linear system, maximizes the total output energy is considered. Previous work has shown that the solution is given by the eigenfunction associated with the maximum eigenvalue in a Hilbert-Schmidt integral equation. Analytical results are available for the case where the transfer function is a low-pass filter. This work is extended by obtaining a numerical solution to the integral equation which allows results for reasonably general transfer functions

  7. Unit 16 - Output

    OpenAIRE

    Unit 16, CC in GIS; Star, Jeffrey L.

    1990-01-01

    This unit discusses issues related to GIS output, including the different types of output possible and the hardware for producing each. It describes text, graphic and digital data that can be generated by a GIS as well as line printers, dot matrix printers/plotters, pen plotters, optical scanners and cathode ray tubes (CRTs) as technologies for generating the output.

  8. MAXIMUM POWEWR POINT TRACKING SYSTEM FOR PHOTOVOLTAIC STATION: A REVIEW

    Directory of Open Access Journals (Sweden)

    I. Elzein

    2015-01-01

    Full Text Available In recent years there has been a growing attention towards the use of renewable energy sources. Among them solar energy is one of the most promising green energy resources due to its environment sustainability and inexhaustibility. However photovoltaic systems (PhV suffer from big cost of equipment and low efficiency. Moreover, the solar cell V-I characteristic is nonlinear and varies with irradiation and temperature. In general, there is a unique point of PhV operation, called the Maximum Power Point (MPP, in which the PV system operates with maximum efficiency and produces its maximum output power. The location of the MPP is not known in advance, but can be located, either through calculation models or by search algorithms. Therefore MPPT techniques are important to maintain the PV array’s high efficiency. Many different techniques for MPPT are discussed. This review paper hopefully will serve as a convenient tool for future work in PhV power conversion.

  9. Inverted relativistic magnetron with a single axial output

    International Nuclear Information System (INIS)

    Ballard, W.P.; Earley, L.M.; Wharton, C.B.

    1986-01-01

    A twelve vane, 1 MV, S-band magnetron has been designed and tested. An inverted design was selected to minimize the parasitic axial electron losses. The stainless steel anode is approximately one wavelength long. One end is partially short-circuited to rf, while the other end has a mode transformer to couple the 3.16 GHz π-mode out into a TM 01 circular waveguide. The magnetron has a loaded output Q of about 100. Operation at 1 MV, 0.31 T, 5 kA routinely produces approx.150 MW peak rms and 100 MW average rms with pulse lengths adjustable from 5 to 70 ns. The microwave power pulse has a rise time of approx.2 ns. The output power is diagnosed using four methods: calorimetry, two circular-waveguide directional couplers installed on the magnetron, two transmitting-receiving systems, and gaseous breakdown. Operation at other voltages and magnetic fields shows that the oscillation frequency is somewhat dependent on the magnetron current. Frequency changes of approx.20 MHz/kA occur as the operating conditions are varied. A series of experiments varying the anode conductivity, the electron emission profile, and the output coupling transformer design showed that none of these significantly increased the output power. Therefore, we have concluded that this magnetron operates in saturation. Because of the anode lifetime and repeatability, this magnetron has the potential to be repetitively pulsed. 36 refs., 16 figs

  10. Fitting and benchmarking of Monte Carlo output parameters for iridium-192 high dose rate brachytherapy source

    International Nuclear Information System (INIS)

    Acquah, F.G.

    2011-01-01

    Brachytherapy, the use of radioactive sources for the treatment of tumours is an important tool in radiation oncology. Accurate calculations of dose delivered to malignant and normal tissues are the main responsibility of the Medical Physics staff. With the use of Treatment Planning System (TPS) computers now becoming a standard practice in the Radiation Oncology Departments, Independent calculations to certify the results of these commercial TPSs are important part of a good quality management system for brachytherapy implants. There are inherent errors in the dose distributions produced by these TPSs due to its failure to account for heterogeneity in the calculation algorithms and Monte Carlo (MC) method seems to be the panacea for these corrections. In this study, a fit functional form using MC output parameters was performed to reduce dose calculation uncertainty using the Matlab software curve fitting applications. This includes the modification of the AAPM TG-43 parameters to accommodate the new developments for a rapid brachytherapy dose rate calculation. Analytical computations were performed to hybridize the anisotropy function, F(r,θ) and radial dose function, g(r) into a single new function f(r,θ) for the Nucletron microSelectron High Dose Rate 'new or v2' (mHDRv2) 192 Ir brachytherapy source. In order to minimize computation time and to improve the accuracy of manual calculations, the dosimetry function f(r,θ) used fewer parameters and formulas for the fit. Using MC outputs as the standard, the percentage errors for the fits were calculated and used to evaluate the average and maximum uncertainties. Dose rate deviation between the MC data and fit were also quantified as errors(E), which showed minimal values. These results showed that the dosimetry parameters from this study as compared to those of MC outputs parameters were in good agreement and better than the results obtained from literature. The work confirms a lot of promise in building robust

  11. Average monthly and annual climate maps for Bolivia

    KAUST Repository

    Vicente-Serrano, Sergio M.

    2015-02-24

    This study presents monthly and annual climate maps for relevant hydroclimatic variables in Bolivia. We used the most complete network of precipitation and temperature stations available in Bolivia, which passed a careful quality control and temporal homogenization procedure. Monthly average maps at the spatial resolution of 1 km were modeled by means of a regression-based approach using topographic and geographic variables as predictors. The monthly average maximum and minimum temperatures, precipitation and potential exoatmospheric solar radiation under clear sky conditions are used to estimate the monthly average atmospheric evaporative demand by means of the Hargreaves model. Finally, the average water balance is estimated on a monthly and annual scale for each 1 km cell by means of the difference between precipitation and atmospheric evaporative demand. The digital layers used to create the maps are available in the digital repository of the Spanish National Research Council.

  12. Regulation of the output power at the resonant converter

    Energy Technology Data Exchange (ETDEWEB)

    Stefanov, Goce G.; Sarac, Vasilija J. [University Goce Delecev-Stip, Faculty of Electrical Engineering, Radovis (Macedonia, The Former Yugoslav Republic of); Karadzinov, Ljupco V., E-mail: goce.stefanov@ugd.edu.mk [University Kiril and Methodyus-Skopje, FEIT Skopje(Macedonia, The Former Yugoslav Republic of)

    2011-07-01

    In this paper a method for regulating an alternating current voltage source with pair of IGBT transistor’s modules, in a full bridge configuration with series resonant converter is given. With the developed method a solution is obtained which can regulate the phase difference between output voltage and current through the inductor, in order to maintain maximum output power. Control electronic via feedback signals regulates the energy transfer to the tank by changing the pulse width of signals which are used as inputs to the gates of the IGBTs. By increasing or decreasing the pulse width transmitted to the various gates of the IGBT the energy transfer to the tank is increased or decreased . PowerSim simulations program is used for development of controlling methodology. Developed method is practically implemented in a prototype of the device for phase control of resonant converter with variable the resonant load. Key words: pulse width method, phase regulation , power converter.

  13. Verification of average daily maximum permissible concentration of styrene in the atmospheric air of settlements under the results of epidemiological studies of the children’s population

    Directory of Open Access Journals (Sweden)

    М.А. Zemlyanova

    2015-03-01

    Full Text Available We presented the materials on the verification of the average daily maximum permissible concentration of styrene in the atmospheric air of settlements performed under the results of own in-depth epidemiological studies of children’s population according to the principles of the international risk assessment practice. It was established that children in the age of 4–7 years when exposed to styrene at the level above 1.2 of threshold level value for continuous exposure develop the negative exposure effects in the form of disorders of hormonal regulation, pigmentary exchange, antioxidative activity, cytolysis, immune reactivity and cytogenetic disbalance which contribute to the increased morbidity of diseases of the central nervous system, endocrine system, respiratory organs, digestion and skin. Based on the proved cause-and-effect relationships between the biomarkers of negative effects and styrene concentration in blood it was demonstrated that the benchmark styrene concentration in blood is 0.002 mg/dm3. The justified value complies with and confirms the average daily styrene concentration in the air of settlements at the level of 0.002 mg/m3 accepted in Russia which provides the safety for the health of population (1 threshold level value for continuous exposure.

  14. Power output of field-based downhill mountain biking.

    Science.gov (United States)

    Hurst, Howard Thomas; Atkins, Stephen

    2006-10-01

    The purpose of this study was to assess the power output of field-based downhill mountain biking. Seventeen trained male downhill cyclists (age 27.1 +/- 5.1 years) competing nationally performed two timed runs of a measured downhill course. An SRM powermeter was used to simultaneously record power, cadence, and speed. Values were sampled at 1-s intervals. Heart rates were recorded at 5-s intervals using a Polar S710 heart rate monitor. Peak and mean power output were 834 +/- 129 W and 75 +/- 26 W respectively. Mean power accounted for only 9% of peak values. Paradoxically, mean heart rate was 168 +/- 9 beats x min(-1) (89% of age-predicted maximum heart rate). Mean cadence (27 +/- 5 rev x min(-1)) was significantly related to speed (r = 0.51; P biking. The poor relationships between power and run time and between cadence and run time suggest they are not essential pre-requisites to downhill mountain biking performance and indicate the importance of riding dynamics to overall performance.

  15. A METHOD FOR DETERMINING THE RADIALLY-AVERAGED EFFECTIVE IMPACT AREA FOR AN AIRCRAFT CRASH INTO A STRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Walker, William C. [ORNL

    2018-02-01

    This report presents a methodology for deriving the equations which can be used for calculating the radially-averaged effective impact area for a theoretical aircraft crash into a structure. Conventionally, a maximum effective impact area has been used in calculating the probability of an aircraft crash into a structure. Whereas the maximum effective impact area is specific to a single direction of flight, the radially-averaged effective impact area takes into consideration the real life random nature of the direction of flight with respect to a structure. Since the radially-averaged effective impact area is less than the maximum effective impact area, the resulting calculated probability of an aircraft crash into a structure is reduced.

  16. Maximum heat flux in boiling in a large volume

    International Nuclear Information System (INIS)

    Bergmans, Dzh.

    1976-01-01

    Relationships are derived for the maximum heat flux qsub(max) without basing on the assumptions of both the critical vapor velocity corresponding to the zero growth rate, and planar interface. The Helmholz nonstability analysis of vapor column has been made to this end. The results of this examination have been used to find maximum heat flux for spherical, cylindric and flat plate heaters. The conventional hydrodynamic theory was found to be incapable of producing a satisfactory explanation of qsub(max) for small heaters. The occurrence of qsub(max) in the present case can be explained by inadequate removal of vapor output from the heater (the force of gravity for cylindrical heaters and surface tension for the spherical ones). In case of flat plate heater the qsub(max) value can be explained with the help of the hydrodynamic theory

  17. Input-output supervisor

    International Nuclear Information System (INIS)

    Dupuy, R.

    1970-01-01

    The input-output supervisor is the program which monitors the flow of informations between core storage and peripheral equipments of a computer. This work is composed of three parts: 1 - Study of a generalized input-output supervisor. With sample modifications it looks like most of input-output supervisors which are running now on computers. 2 - Application of this theory on a magnetic drum. 3 - Hardware requirement for time-sharing. (author) [fr

  18. A novel maximum power point tracking method for PV systems using fuzzy cognitive networks (FCN)

    Energy Technology Data Exchange (ETDEWEB)

    Karlis, A.D. [Electrical Machines Laboratory, Department of Electrical & amp; Computer Engineering, Democritus University of Thrace, V. Sofias 12, 67100 Xanthi (Greece); Kottas, T.L.; Boutalis, Y.S. [Automatic Control Systems Laboratory, Department of Electrical & amp; Computer Engineering, Democritus University of Thrace, V. Sofias 12, 67100 Xanthi (Greece)

    2007-03-15

    Maximum power point trackers (MPPTs) play an important role in photovoltaic (PV) power systems because they maximize the power output from a PV system for a given set of conditions, and therefore maximize the array efficiency. This paper presents a novel MPPT method based on fuzzy cognitive networks (FCN). The new method gives a good maximum power operation of any PV array under different conditions such as changing insolation and temperature. The numerical results show the effectiveness of the proposed algorithm. (author)

  19. Estimation of international output-energy relation. Effects of alternative output measures

    International Nuclear Information System (INIS)

    Shrestha, R.M.

    2000-01-01

    This paper analyzes the output-energy relationship with alternative measures of output and energy. Our analysis rejects the hypothesis of non-diminishing returns to energy consumption when GDP at purchasing power parities is used as the output measure unlike the case with GNP at market exchange rates. This finding also holds when energy input includes the usage of both commercial and traditional fuels. 13 refs

  20. Maximum power point tracker based on fuzzy logic

    International Nuclear Information System (INIS)

    Daoud, A.; Midoun, A.

    2006-01-01

    The solar energy is used as power source in photovoltaic power systems and the need for an intelligent power management system is important to obtain the maximum power from the limited solar panels. With the changing of the sun illumination due to variation of angle of incidence of sun radiation and of the temperature of the panels, Maximum Power Point Tracker (MPPT) enables optimization of solar power generation. The MPPT is a sub-system designed to extract the maximum power from a power source. In the case of solar panels power source. the maximum power point varies as a result of changes in its electrical characteristics which in turn are functions of radiation dose, temperature, ageing and other effects. The MPPT maximum the power output from panels for a given set of conditions by detecting the best working point of the power characteristic and then controls the current through the panels or the voltage across them. Many MPPT methods have been reported in literature. These techniques of MPPT can be classified into three main categories that include: lookup table methods, hill climbing methods and computational methods. The techniques vary according to the degree of sophistication, processing time and memory requirements. The perturbation and observation algorithm (hill climbing technique) is commonly used due to its ease of implementation, and relative tracking efficiency. However, it has been shown that when the insolation changes rapidly, the perturbation and observation method is slow to track the maximum power point. In recent years, the fuzzy controllers are used for maximum power point tracking. This method only requires the linguistic control rules for maximum power point, the mathematical model is not required and therefore the implementation of this control method is easy to real control system. In this paper, we we present a simple robust MPPT using fuzzy set theory where the hardware consists of the microchip's microcontroller unit control card and

  1. Results from transcranial Doppler examination on children and adolescents with sickle cell disease and correlation between the time-averaged maximum mean velocity and hematological characteristics: a cross-sectional analytical study

    Directory of Open Access Journals (Sweden)

    Mary Hokazono

    Full Text Available CONTEXT AND OBJECTIVE: Transcranial Doppler (TCD detects stroke risk among children with sickle cell anemia (SCA. Our aim was to evaluate TCD findings in patients with different sickle cell disease (SCD genotypes and correlate the time-averaged maximum mean (TAMM velocity with hematological characteristics. DESIGN AND SETTING: Cross-sectional analytical study in the Pediatric Hematology sector, Universidade Federal de São Paulo. METHODS: 85 SCD patients of both sexes, aged 2-18 years, were evaluated, divided into: group I (62 patients with SCA/Sß0 thalassemia; and group II (23 patients with SC hemoglobinopathy/Sß+ thalassemia. TCD was performed and reviewed by a single investigator using Doppler ultrasonography with a 2 MHz transducer, in accordance with the Stroke Prevention Trial in Sickle Cell Anemia (STOP protocol. The hematological parameters evaluated were: hematocrit, hemoglobin, reticulocytes, leukocytes, platelets and fetal hemoglobin. Univariate analysis was performed and Pearson's coefficient was calculated for hematological parameters and TAMM velocities (P < 0.05. RESULTS: TAMM velocities were 137 ± 28 and 103 ± 19 cm/s in groups I and II, respectively, and correlated negatively with hematocrit and hemoglobin in group I. There was one abnormal result (1.6% and five conditional results (8.1% in group I. All results were normal in group II. Middle cerebral arteries were the only vessels affected. CONCLUSION: There was a low prevalence of abnormal Doppler results in patients with sickle-cell disease. Time-average maximum mean velocity was significantly different between the genotypes and correlated with hematological characteristics.

  2. The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training.

    Directory of Open Access Journals (Sweden)

    J M Sarabia

    Full Text Available It has been suggested that strength training effects (i.e. neural or structural vary, depending on the total repetitions performed and velocity loss in each training set.The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training.Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]. The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM] and repetitions at maximum power (4 to 9 repetitions, or 'reps'. Volume (sets x repetitions was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%-66.6% of 1RM. The training programme ran over 11 weeks (2 sessions per week; 4-5 sets per session; 3-minute rests between sets, with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST and cortisol (SC concentrations. Rate of perceived exertion (RPE and power output were recorded in all sessions.Following the intermediate test, PPO was increased in the OP group for each load (10.9%-13.2%. Following the post-test, both experimental groups had increased 1RM (11.8%-13.8% and PPO for each load (14.1%-19.6%. Significant decreases in PPO were found for the TT group during all sets (4.9%-15.4%, along with significantly higher RPE (37%.OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE.

  3. An investigation of the maximum penetration level of a photovoltaic (PV) system into a traditional distribution grid

    Science.gov (United States)

    Chalise, Santosh

    Although solar photovoltaic (PV) systems have remained the fastest growing renewable power generating technology, variability as well as uncertainty in the output of PV plants is a significant issue. This rapid increase in PV grid-connected generation presents not only progress in clean energy but also challenges in integration with traditional electric power grids which were designed for transmission and distribution of power from central stations. Unlike conventional electric generators, PV panels do not have rotating parts and thus have no inertia. This potentially causes a problem when the solar irradiance incident upon a PV plant changes suddenly, for example, when scattered clouds pass quickly overhead. The output power of the PV plant may fluctuate nearly as rapidly as the incident irradiance. These rapid power output fluctuations may then cause voltage fluctuations, frequency fluctuations, and power quality issues. These power quality issues are more severe with increasing PV plant power output. This limits the maximum power output allowed from interconnected PV plants. Voltage regulation of a distribution system, a focus of this research, is a prime limiting factor in PV penetration levels. The IEEE 13-node test feeder, modeled and tested in the MATLAB/Simulink environment, was used as an example distribution feeder to analyze the maximum acceptable penetration of a PV plant. The effect of the PV plant's location was investigated, along with the addition of a VAR compensating device (a D-STATCOM in this case). The results were used to develop simple guidelines for determining an initial estimate of the maximum PV penetration level on a distribution feeder. For example, when no compensating devices are added to the system, a higher level of PV penetration is generally achieved by installing the PV plant close to the substation. The opposite is true when a VAR compensator is installed with the PV plant. In these cases, PV penetration levels over 50% may be

  4. Hierarchical Load Tracking Control of a Grid-Connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

    Directory of Open Access Journals (Sweden)

    Yonghui Li

    2015-03-01

    Full Text Available Based on the benchmark solid oxide fuel cell (SOFC dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject to the constraints of fuel utilization factor, stack temperature and output active power. The optimal operating conditions of the grid-connected SOFC were obtained by solving the NLP problem considering the power consumed by the air compressor. With the optimal operating conditions of the SOFC for the maximum efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model.

  5. Bounds on Average Time Complexity of Decision Trees

    KAUST Repository

    Chikalov, Igor

    2011-01-01

    In this chapter, bounds on the average depth and the average weighted depth of decision trees are considered. Similar problems are studied in search theory [1], coding theory [77], design and analysis of algorithms (e.g., sorting) [38]. For any diagnostic problem, the minimum average depth of decision tree is bounded from below by the entropy of probability distribution (with a multiplier 1/log2 k for a problem over a k-valued information system). Among diagnostic problems, the problems with a complete set of attributes have the lowest minimum average depth of decision trees (e.g, the problem of building optimal prefix code [1] and a blood test study in assumption that exactly one patient is ill [23]). For such problems, the minimum average depth of decision tree exceeds the lower bound by at most one. The minimum average depth reaches the maximum on the problems in which each attribute is "indispensable" [44] (e.g., a diagnostic problem with n attributes and kn pairwise different rows in the decision table and the problem of implementing the modulo 2 summation function). These problems have the minimum average depth of decision tree equal to the number of attributes in the problem description. © Springer-Verlag Berlin Heidelberg 2011.

  6. Preliminary Retrospective Analysis of Daily Tomotherapy Output Constancy Checks Using Statistical Process Control.

    Science.gov (United States)

    Mezzenga, Emilio; D'Errico, Vincenzo; Sarnelli, Anna; Strigari, Lidia; Menghi, Enrico; Marcocci, Francesco; Bianchini, David; Benassi, Marcello

    2016-01-01

    The purpose of this study was to retrospectively evaluate the results from a Helical TomoTherapy Hi-Art treatment system relating to quality controls based on daily static and dynamic output checks using statistical process control methods. Individual value X-charts, exponentially weighted moving average charts, and process capability and acceptability indices were used to monitor the treatment system performance. Daily output values measured from January 2014 to January 2015 were considered. The results obtained showed that, although the process was in control, there was an out-of-control situation in the principal maintenance intervention for the treatment system. In particular, process capability indices showed a decreasing percentage of points in control which was, however, acceptable according to AAPM TG148 guidelines. Our findings underline the importance of restricting the acceptable range of daily output checks and suggest a future line of investigation for a detailed process control of daily output checks for the Helical TomoTherapy Hi-Art treatment system.

  7. Monte Carlo simulation of the effect of miniphantom on in-air output ratio

    International Nuclear Information System (INIS)

    Li Jun; Zhu, Timothy C.

    2010-01-01

    Purpose: The aim of the study was to quantify the effect of miniphantoms on in-air output ratio measurements, i.e., to determine correction factors for in-air output ratio. Methods: Monte Carlo (MC) simulations were performed to simulate in-air output ratio measurements by using miniphantoms made of various materials (PMMA, graphite, copper, brass, and lead) and with different longitudinal thicknesses or depths (2-30 g/cm 2 ) in photon beams of 6 and 15 MV, respectively, and with collimator settings ranging from 3x3 to 40x40 cm 2 . EGSnrc and BEAMnrc (2007) software packages were used. Photon energy spectra corresponding to the collimator settings were obtained from BEAMnrc code simulations on a linear accelerator and were used to quantify the components of in-air output ratio correction factors, i.e., attenuation, mass energy absorption, and phantom scatter correction factors. In-air output ratio correction factors as functions of miniphantom material, miniphantom longitudinal thickness, and collimator setting were calculated and compared to a previous experimental study. Results: The in-air output ratio correction factors increase with collimator opening and miniphantom longitudinal thickness for all the materials and for both energies. At small longitudinal thicknesses, the in-air output ratio correction factors for PMMA and graphite are close to 1. The maximum magnitudes of the in-air output ratio correction factors occur at the largest collimator setting (40x40 cm 2 ) and the largest miniphantom longitudinal thickness (30 g/cm 2 ): 1.008±0.001 for 6 MV and 1.012±0.001 for 15 MV, respectively. The MC simulations of the in-air output ratio correction factor confirm the previous experimental study. Conclusions: The study has verified that a correction factor for in-air output ratio can be obtained as a product of attenuation correction factor, mass energy absorption correction factor, and phantom scatter correction factor. The correction factors obtained in the

  8. Output characteristics of 40 kW photovoltaic power generation system in ICT; Ibaraki kosen ni okeru 40 kW taiyoko hatsuden shisutemu no shutsuryoku tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, N. [Ibaraki National College of Tech., Ibaraki (Japan); Tani, T. [Science University of Tokyo, Tokyo (Japan)

    1999-11-25

    The photovoltaic power generation system consists of photovoltaic array and power conditioner of the utility connected system. The photovoltaic array parallelly constitutes 18 serial 30 of the modules of 540 sheets, and there is the generating capacity of largest 40 kW. The power conditioner uses 10 kW four units, and it is tracking with function of the maximum output point. This report examined the unconformable rate of photovoltaic array maximum output operating voltage, current and power in simulation and power conditioner input. (author)

  9. Development of intelligent MPPT (maximum power point tracking) control for a grid-connected hybrid power generation system

    International Nuclear Information System (INIS)

    Hong, Chih-Ming; Ou, Ting-Chia; Lu, Kai-Hung

    2013-01-01

    A hybrid power control system is proposed in the paper, consisting of solar power, wind power, and a diesel-engine. To achieve a fast and stable response for the real power control, an intelligent controller was proposed, which consists of the Wilcoxon (radial basis function network) RBFN and the improved (Elman neural network) ENN for (maximum power point tracking) MPPT. The pitch angle control of wind power uses improved ENN controller, and the output is fed to the wind turbine to achieve the MPPT. The solar array is integrated with an RBFN control algorithm to track the maximum power. MATLAB (MATrix LABoratory)/Simulink was used to build the dynamic model and simulate the solar and diesel-wind hybrid power system. - Highlights: ► To achieve a fast and stable response for the real power control. ► The pitch control of wind power uses improved ENN (Elman neural network) controller to achieve the MPPT (maximum power point tracking). ► The RBFN (radial basis function network) can quickly and accurately track the maximum power output for PV (photovoltaic) array. ► MATLAB was used to build the dynamic model and simulate the hybrid power system. ► This method can reach the desired performance even under different load conditions

  10. A thermoelectric generator using loop heat pipe and design match for maximum-power generation

    KAUST Repository

    Huang, Bin-Juine

    2015-09-05

    The present study focuses on the thermoelectric generator (TEG) using loop heat pipe (LHP) and design match for maximum-power generation. The TEG uses loop heat pipe, a passive cooling device, to dissipate heat without consuming power and free of noise. The experiments for a TEG with 4W rated power show that the LHP performs very well with overall thermal resistance 0.35 K W-1, from the cold side of TEG module to the ambient. The LHP is able to dissipate heat up to 110W and is maintenance free. The TEG design match for maximum-power generation, called “near maximum-power point operation (nMPPO)”, is studied to eliminate the MPPT (maximum-power point tracking controller). nMPPO is simply a system design which properly matches the output voltage of TEG with the battery. It is experimentally shown that TEG using design match for maximum-power generation (nMPPO) performs better than TEG with MPPT.

  11. AT89S52 Microcontroller Based Digital Compass With Voice Output

    Directory of Open Access Journals (Sweden)

    Fahmi Fardiyan Arief

    2008-04-01

    Full Text Available In this paper, the design of digital compass with voice output is described, so that the blind can also use it. The digital compass is designed based on up-graded conventional compass. In the axis direction of conventional compass be added a disc as source of wind direction information, and phototransistor as sensor. The digital compass system is designed, based on AT89S52 microcontroller, as control of all interfaces and read sensor. The LCD component is used as display and ISD 2590 IC as voice recorder. The IC can record with maximum capacity 90 seconds. The voices output of compass is divided into 8 direction from the north, southwest, west and the next. The result showed that the design of digital compass work as like conventional compass completely by voice feature.

  12. Maximum Power Point Tracking Based on Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Nimrod Vázquez

    2015-01-01

    Full Text Available Solar panels, which have become a good choice, are used to generate and supply electricity in commercial and residential applications. This generated power starts with the solar cells, which have a complex relationship between solar irradiation, temperature, and output power. For this reason a tracking of the maximum power point is required. Traditionally, this has been made by considering just current and voltage conditions at the photovoltaic panel; however, temperature also influences the process. In this paper the voltage, current, and temperature in the PV system are considered to be a part of a sliding surface for the proposed maximum power point tracking; this means a sliding mode controller is applied. Obtained results gave a good dynamic response, as a difference from traditional schemes, which are only based on computational algorithms. A traditional algorithm based on MPPT was added in order to assure a low steady state error.

  13. Comparison of fuzzy logic and neural network in maximum power point tracker for PV systems

    Energy Technology Data Exchange (ETDEWEB)

    Ben Salah, Chokri; Ouali, Mohamed [Research Unit on Intelligent Control, Optimization, Design and Optimization of Complex Systems (ICOS), Department of Electrical Engineering, National School of Engineers of Sfax, BP. W, 3038, Sfax (Tunisia)

    2011-01-15

    This paper proposes two methods of maximum power point tracking using a fuzzy logic and a neural network controllers for photovoltaic systems. The two maximum power point tracking controllers receive solar radiation and photovoltaic cell temperature as inputs, and estimated the optimum duty cycle corresponding to maximum power as output. The approach is validated on a 100 Wp PVP (two parallels SM50-H panel) connected to a 24 V dc load. The new method gives a good maximum power operation of any photovoltaic array under different conditions such as changing solar radiation and PV cell temperature. From the simulation and experimental results, the fuzzy logic controller can deliver more power than the neural network controller and can give more power than other different methods in literature. (author)

  14. A step by step selection method for the location and the size of a waste-to-energy facility targeting the maximum output energy and minimization of gate fee.

    Science.gov (United States)

    Kyriakis, Efstathios; Psomopoulos, Constantinos; Kokkotis, Panagiotis; Bourtsalas, Athanasios; Themelis, Nikolaos

    2017-06-23

    This study attempts the development of an algorithm in order to present a step by step selection method for the location and the size of a waste-to-energy facility targeting the maximum output energy, also considering the basic obstacle which is in many cases, the gate fee. Various parameters identified and evaluated in order to formulate the proposed decision making method in the form of an algorithm. The principle simulation input is the amount of municipal solid wastes (MSW) available for incineration and along with its net calorific value are the most important factors for the feasibility of the plant. Moreover, the research is focused both on the parameters that could increase the energy production and those that affect the R1 energy efficiency factor. Estimation of the final gate fee is achieved through the economic analysis of the entire project by investigating both expenses and revenues which are expected according to the selected site and outputs of the facility. In this point, a number of commonly revenue methods were included in the algorithm. The developed algorithm has been validated using three case studies in Greece-Athens, Thessaloniki, and Central Greece, where the cities of Larisa and Volos have been selected for the application of the proposed decision making tool. These case studies were selected based on a previous publication made by two of the authors, in which these areas where examined. Results reveal that the development of a «solid» methodological approach in selecting the site and the size of waste-to-energy (WtE) facility can be feasible. However, the maximization of the energy efficiency factor R1 requires high utilization factors while the minimization of the final gate fee requires high R1 and high metals recovery from the bottom ash as well as economic exploitation of recovered raw materials if any.

  15. Latitudinal Change of Tropical Cyclone Maximum Intensity in the Western North Pacific

    Directory of Open Access Journals (Sweden)

    Jae-Won Choi

    2016-01-01

    Full Text Available This study obtained the latitude where tropical cyclones (TCs show maximum intensity and applied statistical change-point analysis on the time series data of the average annual values. The analysis results found that the latitude of the TC maximum intensity increased from 1999. To investigate the reason behind this phenomenon, the difference of the average latitude between 1999 and 2013 and the average between 1977 and 1998 was analyzed. In a difference of 500 hPa streamline between the two periods, anomalous anticyclonic circulations were strong in 30°–50°N, while anomalous monsoon trough was located in the north of South China Sea. This anomalous monsoon trough was extended eastward to 145°E. Middle-latitude region in East Asia is affected by the anomalous southeasterlies due to these anomalous anticyclonic circulations and anomalous monsoon trough. These anomalous southeasterlies play a role of anomalous steering flows that make the TCs heading toward region in East Asia middle latitude. As a result, TCs during 1999–2013 had higher latitude of the maximum intensity compared to the TCs during 1977–1998.

  16. Interfield dysbalances in research input and output benchmarking: Visualisation by density equalizing procedures

    Directory of Open Access Journals (Sweden)

    Fischer Axel

    2008-08-01

    Full Text Available Abstract Background Historical, social and economic reasons can lead to major differences in the allocation of health system resources and research funding. These differences might endanger the progress in diagnostic and therapeutic approaches of socio-economic important diseases. The present study aimed to assess different benchmarking approaches that might be used to analyse these disproportions. Research in two categories was analysed for various output parameters and compared to input parameters. Germany was used as a high income model country. For the areas of cardiovascular and respiratory medicine density equalizing mapping procedures visualized major geographical differences in both input and output markers. Results An imbalance in the state financial input was present with 36 cardiovascular versus 8 respiratory medicine state-financed full clinical university departments at the C4/W3 salary level. The imbalance in financial input is paralleled by an imbalance in overall quantitative output figures: The 36 cardiology chairs published 2708 articles in comparison to 453 articles published by the 8 respiratory medicine chairs in the period between 2002 and 2006. This is a ratio of 75.2 articles per cardiology chair and 56.63 articles per respiratory medicine chair. A similar trend is also present in the qualitative measures. Here, the 2708 cardiology publications were cited 48337 times (7290 times for respiratory medicine which is an average citation of 17.85 per publication vs. 16.09 for respiratory medicine. The average number of citations per cardiology chair was 1342.69 in contrast to 911.25 citations per respiratory medicine chair. Further comparison of the contribution of the 16 different German states revealed major geographical differences concerning numbers of chairs, published items, total number of citations and average citations. Conclusion Despite similar significances of cardiovascular and respiratory diseases for the global

  17. Output hardcopy devices

    CERN Document Server

    Durbeck, Robert

    1988-01-01

    Output Hardcopy Devices provides a technical summary of computer output hardcopy devices such as plotters, computer output printers, and CRT generated hardcopy. Important related technical areas such as papers, ribbons and inks, color techniques, controllers, and character fonts are also covered. Emphasis is on techniques primarily associated with printing, as well as the plotting capabilities of printing devices that can be effectively used for computer graphics in addition to their various printing functions. Comprised of 19 chapters, this volume begins with an introduction to vector and ras

  18. Design and implementation of a microcontroller-based maximum power point tracking fuzzy solar-charge controller

    Energy Technology Data Exchange (ETDEWEB)

    Qazalbash, A.A.; Iqbal, T.; Shafiq, M.Z. [National Univ. of Sciences and Technology, Rawalpindi (Pakistan). Dept. of Electrical Engineering

    2007-07-01

    Photovoltaic (PV) solar arrays are particularly useful for electrical power generation in remote, off-grid areas in developing countries. However, PV arrays offer a small power to area ratio, resulting in the need for more PV arrays which increases the cost of the system. In order to improve the profitability of PV arrays, the power extraction from available PV array systems must be maximized. This paper presented an analysis, modeling and implementation of an efficient solar charge controller. It was shown that the maximum power of a photovoltaic system depends largely on temperature and insolation. A perturb and observe algorithm was used for maximum power point tracking (MPPT). MPPT maximizes the efficiency of a solar PV system. A solar charge controller determines the optimal values of output current and voltage of converters to maximize power output for battery charging. In order to improve performance and implement the perturb and observe algorithm, the authors designed a fuzzy rule-based system in which a solar charge controller worked with a PWM controlled DC-DC converter for battery charging. The system was implemented on a low-cost PIC microcontroller. Results were better than conventional techniques in power efficiency. Swift maximum power point tracking was obtained. 13 refs., 1 tab., 11 figs.

  19. Development of an Intelligent Maximum Power Point Tracker Using an Advanced PV System Test Platform

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Amoiridis, Anastasios; Beres, Remus Narcis

    2013-01-01

    The performance of photovoltaic systems is often reduced by the presence of partial shadows. The system efficiency and availability can be improved by a maximum power point tracking algorithm that is able to detect partial shadow conditions and to optimize the power output. This work proposes...... an intelligent maximum power point tracking method that monitors the maximum power point voltage and triggers a current-voltage sweep only when a partial shadow is detected, therefore minimizing power loss due to repeated current-voltage sweeps. The proposed system is validated on an advanced, flexible...... photovoltaic inverter system test platform that is able to reproduce realistic partial shadow conditions, both in simulation and on hardware test system....

  20. A novel 3D detector configuration enabling high quantum efficiency, low crosstalk, and low output capacitance

    International Nuclear Information System (INIS)

    Aurola, A.; Marochkin, V.; Tuuva, T.

    2016-01-01

    The benefits of pixelated planar direct conversion semiconductor radiation detectors comprising a thick fully depleted substrate are that they offer low crosstalk, small output capacitance, and that the planar configuration simplifies manufacturing. In order to provide high quantum efficiency for high energy X-rays and Gamma-rays such a radiation detector should be as thick as possible. The maximum thickness and thus the maximum quantum efficiency has been limited by the substrate doping concentration: the lower the substrate doping the thicker the detector can be before reaching the semiconductor material's electric breakdown field. Thick direct conversion semiconductor detectors comprising vertical three-dimensional electrodes protruding through the substrate have been previously proposed by Sherwood Parker in order to promote rapid detection of radiation. An additional advantage of these detectors is that their thickness is not limited by the substrate doping, i.e., the size of the maximum electric field value in the detector does not depend on detector thickness. However, the thicker the substrate of such three dimensional detectors is the larger the output capacitance is and thus the larger the output noise is. In the novel direct conversion pixelated radiation detector utilizing a novel three dimensional semiconductor architecture, which is proposed in this work, the detector thickness is not limited by the substrate doping and the output capacitance is small and does not depend on the detector thickness. In addition, by incorporating an additional node to the novel three-dimensional semiconductor architecture it can be utilized as a high voltage transistor that can deliver current across high voltages. Furthermore, it is possible to connect a voltage difference of any size to the proposed novel three dimensional semiconductor architecture provided that it is thick enough—this is a novel feature that has not been previously possible for semiconductor

  1. Guaranteeing high output of a mine

    Energy Technology Data Exchange (ETDEWEB)

    Shetser, M G

    1983-05-01

    Operation of the Im. Kalinina coal mine in the Central Donbass is evluated. Seventeen coal seams, on the average 0.87 m thick, are prone to methane and coal dust explosions and to rock bursts. Some of the seams are also prone to spontaneous combustion. Rock layers in the roofs are prone to rock falls. Mining depth ranges from 740 to 850 m. Another working level is being constructed at a depth of 960 m. The steep coal seams are mined by means of the ANShch shield systems and the KGU system (with the 'Poisk' cutter loader). Strata control methods used in the mine are evaluated. Design of timber cribbings used for strata control in inclined workings is shown in a scheme. Construction of coal chutes and strata control in coal chutes are also described. Operation of KGU-1 powered supports which have been used in the mine for 10 years is evaluated. Improved strata control permitted daily coal output from a working face to be increased from 135 t in 1979 to 169 t in 1982. Yearly coal output increased from 605,000 t to 760,000 t. Labor productivity increased from 21.1 t/month to 25.9 t/month per miner. (In Russian)

  2. Evaluating the output stability of LINAC with a reference detector using 3D water phantom

    International Nuclear Information System (INIS)

    Shimozato, Tomohiro; Kojima, Tomo; Sakamoto, Masataka; Hata, Yuji; Sasaki, Koji; Araki, Noriyuki

    2013-01-01

    We report the discovery of abnormal fluctuations in the output obtained when measuring a water phantom and adjustments that reduce these outliers. Using a newly developed three-dimensional scanning water phantom system, we obtained the depth dose and off-axis dose ratio required for the beam data of a medical linear accelerator (LINAC). The field and reference detectors were set such that the measured values could be viewed in real time. We confirmed the scanning data using the field detector and the change in the output using the reference detector while measuring by using the water phantom. Prior to output adjustment of the LINAC, we observed output abnormalities as high as 18.4%. With optimization of accelerator conditions, the average of the output fluctuation width was reduced to less than ±0.5%. Through real-time graphing of reference detector measurements during measurement of field detector, we were able to rapidly identify abnormal fluctuations. Although beam data collected during radiation treatment planning are corrected for output fluctuations, it is possible that sudden abnormal fluctuations actually occur in the output. Therefore, the equipment should be tested for output fluctuations at least once a year. Even after minimization of fluctuations, we recommend determining the potential dose administered to the human body taking into account the width of the output fluctuation. (author)

  3. General and Local: Averaged k-Dependence Bayesian Classifiers

    Directory of Open Access Journals (Sweden)

    Limin Wang

    2015-06-01

    Full Text Available The inference of a general Bayesian network has been shown to be an NP-hard problem, even for approximate solutions. Although k-dependence Bayesian (KDB classifier can construct at arbitrary points (values of k along the attribute dependence spectrum, it cannot identify the changes of interdependencies when attributes take different values. Local KDB, which learns in the framework of KDB, is proposed in this study to describe the local dependencies implicated in each test instance. Based on the analysis of functional dependencies, substitution-elimination resolution, a new type of semi-naive Bayesian operation, is proposed to substitute or eliminate generalization to achieve accurate estimation of conditional probability distribution while reducing computational complexity. The final classifier, averaged k-dependence Bayesian (AKDB classifiers, will average the output of KDB and local KDB. Experimental results on the repository of machine learning databases from the University of California Irvine (UCI showed that AKDB has significant advantages in zero-one loss and bias relative to naive Bayes (NB, tree augmented naive Bayes (TAN, Averaged one-dependence estimators (AODE, and KDB. Moreover, KDB and local KDB show mutually complementary characteristics with respect to variance.

  4. Economy-wide material input/output and dematerialization analysis of Jilin Province (China).

    Science.gov (United States)

    Li, MingSheng; Zhang, HuiMin; Li, Zhi; Tong, LianJun

    2010-06-01

    In this paper, both direct material input (DMI) and domestic processed output (DPO) of Jilin Province in 1990-2006 were calculated and then based on these two indexes, a dematerialization model was established. The main results are summarized as follows: (1) both direct material input and domestic processed output increase at a steady rate during 1990-2006, with average annual growth rates of 4.19% and 2.77%, respectively. (2) The average contribution rate of material input to economic growth is 44%, indicating that the economic growth is visibly extensive. (3) During the studied period, accumulative quantity of material input dematerialization is 11,543 x 10(4) t and quantity of waste dematerialization is 5,987 x10(4) t. Moreover, dematerialization gaps are positive, suggesting that the potential of dematerialization has been well fulfilled. (4) In most years of the analyzed period, especially 2003-2006, the economic system of Jilin Province represents an unsustainable state. The accelerated economic growth relies mostly on excessive resources consumption after the Revitalization Strategy of Northeast China was launched.

  5. From Static Output Feedback to Structured Robust Static Output Feedback: A Survey

    OpenAIRE

    Sadabadi , Mahdieh ,; Peaucelle , Dimitri

    2016-01-01

    This paper reviews the vast literature on static output feedback design for linear time-invariant systems including classical results and recent developments. In particular, we focus on static output feedback synthesis with performance specifications, structured static output feedback, and robustness. The paper provides a comprehensive review on existing design approaches including iterative linear matrix inequalities heuristics, linear matrix inequalities with rank constraints, methods with ...

  6. The Type-2 Fuzzy Logic Controller-Based Maximum Power Point Tracking Algorithm and the Quadratic Boost Converter for Pv System

    Science.gov (United States)

    Altin, Necmi

    2018-05-01

    An interval type-2 fuzzy logic controller-based maximum power point tracking algorithm and direct current-direct current (DC-DC) converter topology are proposed for photovoltaic (PV) systems. The proposed maximum power point tracking algorithm is designed based on an interval type-2 fuzzy logic controller that has an ability to handle uncertainties. The change in PV power and the change in PV voltage are determined as inputs of the proposed controller, while the change in duty cycle is determined as the output of the controller. Seven interval type-2 fuzzy sets are determined and used as membership functions for input and output variables. The quadratic boost converter provides high voltage step-up ability without any reduction in performance and stability of the system. The performance of the proposed system is validated through MATLAB/Simulink simulations. It is seen that the proposed system provides high maximum power point tracking speed and accuracy even for fast changing atmospheric conditions and high voltage step-up requirements.

  7. Input-output analysis of high-speed axisymmetric isothermal jet noise

    Science.gov (United States)

    Jeun, Jinah; Nichols, Joseph W.; Jovanović, Mihailo R.

    2016-04-01

    We use input-output analysis to predict and understand the aeroacoustics of high-speed isothermal turbulent jets. We consider axisymmetric linear perturbations about Reynolds-averaged Navier-Stokes solutions of ideally expanded turbulent jets with jet Mach numbers 0.6 parabolized stability equations (PSE), and this mode dominates the response. For subsonic jets, however, the singular values indicate that the contributions of sub-optimal modes to noise generation are nearly equal to that of the optimal mode, explaining why the PSE do not fully capture the far-field sound in this case. Furthermore, high-fidelity large eddy simulation (LES) is used to assess the prevalence of sub-optimal modes in the unsteady data. By projecting LES source term data onto input modes and the LES acoustic far-field onto output modes, we demonstrate that sub-optimal modes of both types are physically relevant.

  8. Effects of practices and teaching methods on different measures of the educational output: the case of Spanish universities

    Directory of Open Access Journals (Sweden)

    Pedro José PÉREZ VÁZQUEZ

    2016-07-01

    Full Text Available This article analyses the relationships between the educational resources applied in higher education and two types of measures of educational output: average grade obtained by students and the contribution of studies to the development of diverse professional competencies. The relationships are modelled using multi-level production function equations, with the corresponding output measure as the dependent variable. The explanatory variables are the prevalence of various teaching/learning modes and a set of variables that control for the behaviour of students during their studies and for their personal attributes. Estimates, using data from European project Reflex, show significant relationships between the teaching and learning methods used and the alternative measures of educational output considered. The results show that attending lectures has the greatest impact on average grades; nonetheless, more proactive learning methods such as problem-based learning, internships and work provision, and practical knowledge are most influential for the development of professional competencies.

  9. GDP Growth, Potential Output, and Output Gaps in Mexico

    OpenAIRE

    Ebrima A Faal

    2005-01-01

    This paper analyzes the sources of Mexico's economic growth since the 1960s and compares various decompositions of historical growth into its trend and cyclical components. The role of the implied output gaps in the inflationary process is then assessed. Looking ahead, the paper presents medium-term paths for GDP based on alternative assumptions for productivity growth rates. The results indicate that the most important factor underlying the slowdown in output growth was a decline in trend to...

  10. Comparison of soft-input-soft-output detection methods for dual-polarized quadrature duobinary system

    Science.gov (United States)

    Chang, Chun; Huang, Benxiong; Xu, Zhengguang; Li, Bin; Zhao, Nan

    2018-02-01

    Three soft-input-soft-output (SISO) detection methods for dual-polarized quadrature duobinary (DP-QDB), including maximum-logarithmic-maximum-a-posteriori-probability-algorithm (Max-log-MAP)-based detection, soft-output-Viterbi-algorithm (SOVA)-based detection, and a proposed SISO detection, which can all be combined with SISO decoding, are presented. The three detection methods are investigated at 128 Gb/s in five-channel wavelength-division-multiplexing uncoded and low-density-parity-check (LDPC) coded DP-QDB systems by simulations. Max-log-MAP-based detection needs the returning-to-initial-states (RTIS) process despite having the best performance. When the LDPC code with a code rate of 0.83 is used, the detecting-and-decoding scheme with the SISO detection does not need RTIS and has better bit error rate (BER) performance than the scheme with SOVA-based detection. The former can reduce the optical signal-to-noise ratio (OSNR) requirement (at BER=10-5) by 2.56 dB relative to the latter. The application of the SISO iterative detection in LDPC-coded DP-QDB systems makes a good trade-off between requirements on transmission efficiency, OSNR requirement, and transmission distance, compared with the other two SISO methods.

  11. Structure and Output Characteristics of a TEM Array Fitted to a Fin Heat Exchanger

    Science.gov (United States)

    Zhang, Z.; Chen, L. N.; Chen, Z. J.; Xiao, G. Q.; Liu, Z. J.

    2015-06-01

    In the design of a thermoelectric generator, both the heat transfer area and the number of thermoelectric modules (TEMs) should be increased accordingly as the generator power increases; crucially, both aspects need to be coordinated. A kilowatt thermoelectric generator with a fin heat exchanger is proposed for use in a constant-speed diesel generator unit. Interior fins enhance convective heat transfer, whereas an exterior fin segment increases the heat transfer area. The heat transfer surface is double that of a plane heat exchanger, and the temperature field over the exterior fins is constrained to a one-dimensional distribution. Between adjoining exterior fins, there is a cooling water channel with trapezoid cross-section, enabling compact TEMs and cooling them. Hence, more TEMs are built as a series-parallel array of TEMs with lower resistance and more stable output current. Under nonuniform conditions, to prevent circulation and energy loss, bypass diodes and antidiodes are added. Experiments and numerical calculations show that, with matching and optimization of the heat exchanger and TEM array, a stable maximum output power is obtainable from the interior of the thermoelectric generator system, which can be connected to an external maximum power point tracking system.

  12. Independence, Odd Girth, and Average Degree

    DEFF Research Database (Denmark)

    Löwenstein, Christian; Pedersen, Anders Sune; Rautenbach, Dieter

    2011-01-01

      We prove several tight lower bounds in terms of the order and the average degree for the independence number of graphs that are connected and/or satisfy some odd girth condition. Our main result is the extension of a lower bound for the independence number of triangle-free graphs of maximum...... degree at most three due to Heckman and Thomas [Discrete Math 233 (2001), 233–237] to arbitrary triangle-free graphs. For connected triangle-free graphs of order n and size m, our result implies the existence of an independent set of order at least (4n−m−1) / 7.  ...

  13. Speaking Math--A Voice Input, Speech Output Calculator for Students with Visual Impairments

    Science.gov (United States)

    Bouck, Emily C.; Flanagan, Sara; Joshi, Gauri S.; Sheikh, Waseem; Schleppenbach, Dave

    2011-01-01

    This project explored a newly developed computer-based voice input, speech output (VISO) calculator. Three high school students with visual impairments educated at a state school for the blind and visually impaired participated in the study. The time they took to complete assessments and the average number of attempts per problem were recorded…

  14. The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training

    Science.gov (United States)

    Moya-Ramón, M.; Hernández-Davó, J. L.; Fernandez-Fernandez, J.; Sabido, R.

    2017-01-01

    Background It has been suggested that strength training effects (i.e. neural or structural) vary, depending on the total repetitions performed and velocity loss in each training set. Purpose The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training). Methods Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]). The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM]) and repetitions at maximum power (4 to 9 repetitions, or ‘reps’). Volume (sets x repetitions) was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%–66.6% of 1RM). The training programme ran over 11 weeks (2 sessions per week; 4–5 sets per session; 3-minute rests between sets), with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO) with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST) and cortisol (SC) concentrations. Rate of perceived exertion (RPE) and power output were recorded in all sessions. Results Following the intermediate test, PPO was increased in the OP group for each load (10.9%–13.2%). Following the post-test, both experimental groups had increased 1RM (11.8%–13.8%) and PPO for each load (14.1%–19.6%). Significant decreases in PPO were found for the TT group during all sets (4.9%–15.4%), along with significantly higher RPE (37%). Conclusion OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE. PMID:29053725

  15. Estimation of PV output power in moving and rocking hybrid energy marine ships

    International Nuclear Information System (INIS)

    Liu, Hongda; Zhang, Qing; Qi, Xiaoxia; Han, Yang; Lu, Fang

    2017-01-01

    Highlights: •A mathematical model for characterizing the ship PV output power is developed. •The impacts of the sea condition and ship type on the PV output power are analyzed. •The hybrid energy storage system is used to stabilize the PV fluctuation powers. •A SC configuration method based on maximum half period is applied. -- Abstract: In recent years, the application of solar energy and energy storage to ship power systems has shown promise as a method for both reducing annual carbon and nitrogen oxide emissions and improving ship energy efficiency in the maritime shipping industry. When a ship navigates at sea, it encounters a constant rocking motion that is affected by both the surrounding sea conditions and the ship’s navigation parameters. This motion increases the uncertainty involved in using solar energy and accelerates the aging of the ship’s energy storage battery to some extent. In this study, a universal mathematical model is established for the power generation by photovoltaic (PV) modules in which both the sea conditions and the ship’s integrated motion, including its basic movement along with the motion caused by rocking, are taken into account. Based on this model, the fluctuation characteristics of a ship’s PV output power are studied and determined using three different simulation scenarios. A binary energy storage scheme based on a decoupled PV output power is proposed in order to both stabilize the small-period PV power fluctuations and slow the aging of the actual battery caused by rocking. In addition, a super-capacitor (SC) configuration is constructed based on a maximum half cycle. Finally, the optimal energy storage capacities for this green ship are compared under both rocking and moving motion. In the case of rocking motion, the SCs are able to achieve an approximately 24.8–35.0% reduction in battery replacement. A shipping route between Shanghai, China and Sydney, Australia is considered to validate the practicality

  16. Design and characterization of a high-power ultrasound driver with ultralow-output impedance

    Science.gov (United States)

    Lewis, George K.; Olbricht, William L.

    2009-11-01

    We describe a pocket-sized ultrasound driver with an ultralow-output impedance amplifier circuit (less than 0.05 Ω) that can transfer more than 99% of the voltage from a power supply to the ultrasound transducer with minimal reflections. The device produces high-power acoustical energy waves while operating at lower voltages than conventional ultrasound driving systems because energy losses owing to mismatched impedance are minimized. The peak performance of the driver is measured experimentally with a PZT-4, 1.54 MHz, piezoelectric ceramic, and modeled using an adjusted Mason model over a range of transducer resonant frequencies. The ultrasound driver can deliver a 100 Vpp (peak to peak) square-wave signal across 0-8 MHz ultrasound transducers in 5 ms bursts through continuous wave operation, producing acoustic powers exceeding 130 W. Effects of frequency, output impedance of the driver, and input impedance of the transducer on the maximum acoustic output power of piezoelectric transducers are examined. The small size, high power, and efficiency of the ultrasound driver make this technology useful for research, medical, and industrial ultrasonic applications.

  17. Bias of averages in life-cycle footprinting of infrastructure: truck and bus case studies.

    Science.gov (United States)

    Taptich, Michael N; Horvath, Arpad

    2014-11-18

    The life-cycle output (e.g., level of service) of infrastructure systems heavily influences their normalized environmental footprint. Many studies and tools calculate emission factors based on average productivity; however, the performance of these systems varies over time and space. We evaluate the appropriate use of emission factors based on average levels of service by comparing them to those reflecting a distribution of system outputs. For the provision of truck and bus services where fuel economy is assumed constant over levels of service, emission factor estimation biases, described by Jensen's inequality, always result in larger-than-expected environmental impacts (3%-400%) and depend strongly on the variability and skew of truck payloads and bus ridership. Well-to-wheel greenhouse gas emission factors for diesel trucks in California range from 87 to 1,500 g of CO2 equivalents per ton-km, depending on the size and type of trucks and the services performed. Along a bus route in San Francisco, well-to-wheel emission factors ranged between 53 and 940 g of CO2 equivalents per passenger-km. The use of biased emission factors can have profound effects on various policy decisions. If average emission rates must be used, reflecting a distribution of productivity can reduce emission factor biases.

  18. Long-term energy output estimation for photovoltaic energy systems using synthetic solar irradiation data

    International Nuclear Information System (INIS)

    Celik, A.N.

    2003-01-01

    A general methodology is presented to estimate the monthly average daily energy output from photovoltaic energy systems. Energy output is estimated from synthetically generated solar radiation data. The synthetic solar radiation data are generated based on the cumulative frequency distribution of the daily clearness index, given as a function of the monthly clearness index. Two sets of synthetic solar irradiation data are generated: 3- and 4-day months. In the 3-day month, each month is represented by 3 days and in the 4-day month, by 4 days. The 3- and 4-day solar irradiation data are synthetically generated for each month and the corresponding energy outputs are calculated. A total of 8-year long measured hourly solar irradiation data, from five different locations in the world, is used to validate the new model. The monthly energy output values calculated from the synthetic solar irradiation data are compared to those calculated from the measured hour-by-hour data. It is shown that when the measured solar radiation data do not exist for a particular location or reduced data set is advantageous, the energy output from photovoltaic converters could be correctly calculated

  19. "Minimum input, maximum output, indeed!" Teaching Collocations ...

    African Journals Online (AJOL)

    Fifty-nine EFL college students participated in the study, and they received two 75-minute instructions between pre- and post-tests: one on the definition of colloca-tion and its importance, and the other on the skill of looking up collocational information in the Naver Dictionary — an English–Korean online dictionary. During ...

  20. Zipf's law, power laws and maximum entropy

    International Nuclear Information System (INIS)

    Visser, Matt

    2013-01-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified. (paper)

  1. Application of a Linear Input/Output Model to Tankless Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Butcher T.; Schoenbauer, B.

    2011-12-31

    In this study, the applicability of a linear input/output model to gas-fired, tankless water heaters has been evaluated. This simple model assumes that the relationship between input and output, averaged over both active draw and idle periods, is linear. This approach is being applied to boilers in other studies and offers the potential to make a small number of simple measurements to obtain the model parameters. These parameters can then be used to predict performance under complex load patterns. Both condensing and non-condensing water heaters have been tested under a very wide range of load conditions. It is shown that this approach can be used to reproduce performance metrics, such as the energy factor, and can be used to evaluate the impacts of alternative draw patterns and conditions.

  2. Book Trade Research and Statistics. Prices of U.S. and Foreign Published Materials; Book Title Output and Average Prices: 2000 Final and 2001 Preliminary Figures; Book Sales Statistics, 2001: AAP Preliminary Estimates; U.S. Book Exports and Imports: 2001; Number of Book Outlets in the United States and Canada; Review Media Statistics.

    Science.gov (United States)

    Sullivan, Sharon G.; Barr, Catherine; Grabois, Andrew

    2002-01-01

    Includes six articles that report on prices of U.S. and foreign published materials; book title output and average prices; book sales statistics; book exports and imports; book outlets in the U.S. and Canada; and review media statistics. (LRW)

  3. Multichannel display system with automatic sequential output of analog data

    International Nuclear Information System (INIS)

    Bykovskii, Yu.A.; Gruzinov, A.E.; Lagoda, V.B.

    1989-01-01

    The authors describe a device that, with maximum simplicity and autonomy, permits parallel data display from 16 measuring channels with automatic output to the screen of a storage oscilloscope in ∼ 50 μsec. The described device can be used to study the divergence characteristics of the ion component of plasma sources and in optical and x-ray spectroscopy of pulsed processes. Owing to its compactness and autonomy, the device can be located in the immediate vicinity of the detectors (for example, inside a vacuum chamber), which allows the number of vacuum electrical lead-ins and the induction level to be reduced

  4. Capacitive divider for output voltage measurement of intense electron beam accelerator

    International Nuclear Information System (INIS)

    Ding Desheng; Yi Lingzhi; Yu Binxiong; Hong Zhiqiang; Liu Jinliang

    2012-01-01

    A kind of simple-mechanism, easy-disassembly self-integrating capacitive divider used for measuring diode output voltage of intense electron beam accelerator (IEBA) is developed. The structure of the capacitive divider is described, and the capacitance value of the capacitive divider is calculated by theoretical analysis and electromagnetic simulation. The dependence of measurement voltage on electrical parameters such as stray capacitance, earth capacitance of front resistance is obtained by PSpice simulation. Measured waveforms appear overshoot phenomenon when stray capacitance of front resistance is larger, and the wavefront will be affected when earth capacitance of front resistance is larger. The diode output voltage waveforms of intense electron beam accelerator, are measured by capacitive divider and calibrated by water resistance divider, which is accordance with that measured by a resistive divider, the division ratio is about 563007. The designed capacitive divider can be used to measure high-voltage pulse with 100 ns full width at half maximum. (authors)

  5. Effect of tank geometry on its average performance

    Science.gov (United States)

    Orlov, Aleksey A.; Tsimbalyuk, Alexandr F.; Malyugin, Roman V.; Leontieva, Daria A.; Kotelnikova, Alexandra A.

    2018-03-01

    The mathematical model of non-stationary filling of vertical submerged tanks with gaseous uranium hexafluoride is presented in the paper. There are calculations of the average productivity, heat exchange area, and filling time of various volumes tanks with smooth inner walls depending on their "height : radius" ratio as well as the average productivity, degree, and filling time of horizontal ribbing tank with volume 6.10-2 m3 with change central hole diameter of the ribs. It has been shown that the growth of "height / radius" ratio in tanks with smooth inner walls up to the limiting values allows significantly increasing tank average productivity and reducing its filling time. Growth of H/R ratio of tank with volume 1.0 m3 to the limiting values (in comparison with the standard tank having H/R equal 3.49) augments tank productivity by 23.5 % and the heat exchange area by 20%. Besides, we have demonstrated that maximum average productivity and a minimum filling time are reached for the tank with volume 6.10-2 m3 having central hole diameter of horizontal ribs 6.4.10-2 m.

  6. System convergence in transport models: algorithms efficiency and output uncertainty

    DEFF Research Database (Denmark)

    Rich, Jeppe; Nielsen, Otto Anker

    2015-01-01

    of this paper is to analyse convergence performance for the external loop and to illustrate how an improper linkage between the converging parts can lead to substantial uncertainty in the final output. Although this loop is crucial for the performance of large-scale transport models it has not been analysed...... much in the literature. The paper first investigates several variants of the Method of Successive Averages (MSA) by simulation experiments on a toy-network. It is found that the simulation experiments produce support for a weighted MSA approach. The weighted MSA approach is then analysed on large......-scale in the Danish National Transport Model (DNTM). It is revealed that system convergence requires that either demand or supply is without random noise but not both. In that case, if MSA is applied to the model output with random noise, it will converge effectively as the random effects are gradually dampened...

  7. Early-Transition Output Decline Revisited

    Directory of Open Access Journals (Sweden)

    Crt Kostevc

    2016-05-01

    Full Text Available In this paper we revisit the issue of aggregate output decline that took place in the early transition period. We propose an alternative explanation of output decline that is applicable to Central- and Eastern-European countries. In the first part of the paper we develop a simple dynamic general equilibrium model that builds on work by Gomulka and Lane (2001. In particular, we consider price liberalization, interpreted as elimination of distortionary taxation, as a trigger of the output decline. We show that price liberalization in interaction with heterogeneous adjustment costs and non-employment benefits lead to aggregate output decline and surge in wage inequality. While these patterns are consistent with actual dynamics in CEE countries, this model cannot generate output decline in all sectors. Instead sectors that were initially taxed even exhibit output growth. Thus, in the second part we consider an alternative general equilibrium model with only one production sector and two types of labor and distortion in a form of wage compression during the socialist era. The trigger for labor mobility and consequently output decline is wage liberalization. Assuming heterogeneity of workers in terms of adjustment costs and non-employment benefits can explain output decline in all industries.

  8. Laser fiber cleaving techniques: effects on tip morphology and power output.

    Science.gov (United States)

    Vassantachart, Janna M; Lightfoot, Michelle; Yeo, Alexander; Maldonado, Jonathan; Li, Roger; Alsyouf, Muhannad; Martin, Jacob; Lee, Michael; Olgin, Gaudencio; Baldwin, D Duane

    2015-01-01

    Proper cleaving of reusable laser fibers is needed to maintain optimal functionality. This study quantifies the effect of different cleaving tools on power output of the holmium laser fiber and demonstrates morphologic changes using microscopy. The uncleaved tips of new 272 μm reusable laser fibers were used to obtain baseline power transmission values at 3 W (0.6 J, 5 Hz). Power output for each of four cleaving techniques-11-blade scalpel, scribe pen cleaving tool, diamond cleaving wheel, and suture scissors-was measured in a single-blinded fashion. Dispersion of light from the fibers was compared with manufacturer specifications and rated as "ideal," "acceptable," or "unacceptable" by blinded reviewers. The fiber tips were also imaged using confocal and scanning electron microscopy. Independent samples Kruskal-Wallis test and chi square were used for statistical analysis (αtrend that was highly significant (Ptrend as the power output results (P<0.001). Microscopy showed that the scribe pen produced small defects along the fiber cladding but maintained a smooth, flat core surface. The other cleaving techniques produced defects on both the core and cladding. Cleaving techniques produce a significant effect on the initial power transmitted by reusable laser fibers. The scribe pen cleaving tool produced the most consistent and highest average power output.

  9. High-power narrow-linewidth quasi-CW diode-pumped TEM00 1064 nm Nd:YAG ring laser.

    Science.gov (United States)

    Liu, Yuan; Wang, Bao-shan; Xie, Shi-yong; Bo, Yong; Wang, Peng-yuan; Zuo, Jun-wei; Xu, Yi-ting; Xu, Jia-lin; Peng, Qin-jun; Cui, Da-fu; Xu, Zu-yan

    2012-04-01

    We demonstrated a high average power, narrow-linewidth, quasi-CW diode-pumped Nd:YAG 1064 nm laser with near-diffraction-limited beam quality. A symmetrical three-mirror ring cavity with unidirectional operation elements and an etalon was employed to realize the narrow-linewidth laser output. Two highly efficient laser modules and a 90° quartz rotator for birefringence compensation were used for the high output power. The maximum average output power of 62.5 W with the beam quality factor M(2) of 1.15 was achieved under a pump power of 216 W at a repetition rate of 500 Hz, corresponding to the optical-to-optical conversion efficiency of 28.9%. The linewidth of the laser at the maximum output power was measured to be less than 0.2 GHz.

  10. Diode-pumped continuous-wave and passively Q-switched Nd:GdLuAG laser at 1443.9 nm

    Science.gov (United States)

    Wu, Qianwen; Liu, Zhaojun; Zhang, Sasa; Cong, Zhenghua; Guan, Chen; Xue, Feng; Chen, Hui; Huang, Qingjie; Xu, Xiaodong; Xu, Jun; Qin, Zengguang

    2017-12-01

    We investigated the 1443.9 nm laser characteristics of Nd:GdLuAG crystal. Diode-end-pumping configuration was employed under both continuous-wave (CW) and passively Q-switched operations. For CW operation, the maximum average output power was 1.36 W with a slope efficiency of 15%. By using a V3+:YAG crystal as the saturable absorber, we obtained the maximum average output power of 164 mW under Q-switched operation. The corresponding pulse energy was 29.3 μJ and pulse duration was 59 ns.

  11. An Experimental Observation of Axial Variation of Average Size of Methane Clusters in a Gas Jet

    International Nuclear Information System (INIS)

    Ji-Feng, Han; Chao-Wen, Yang; Jing-Wei, Miao; Jian-Feng, Lu; Meng, Liu; Xiao-Bing, Luo; Mian-Gong, Shi

    2010-01-01

    Axial variation of average size of methane clusters in a gas jet produced by supersonic expansion of methane through a cylindrical nozzle of 0.8 mm in diameter is observed using a Rayleigh scattering method. The scattered light intensity exhibits a power scaling on the backing pressure ranging from 16 to 50 bar, and the power is strongly Z dependent varying from 8.4 (Z = 3 mm) to 5.4 (Z = 11 mm), which is much larger than that of the argon cluster. The scattered light intensity versus axial position shows that the position of 5 mm has the maximum signal intensity. The estimation of the average cluster size on axial position Z indicates that the cluster growth process goes forward until the maximum average cluster size is reached at Z = 9 mm, and the average cluster size will decrease gradually for Z > 9 mm

  12. The impact of monetary policy on output and inflation in India: A frequency domain analysis

    Directory of Open Access Journals (Sweden)

    Salunkhe Bhavesh

    2017-01-01

    Full Text Available In the recent past, several attempts by the RBI to control inflation through tight monetary policy have ended up slowing the growth process, thereby provoking prolonged discussion among academics and policymakers about the efficacy of monetary policy in India. Against this backdrop, the present study attempts to estimate the causal relationship between monetary policy and its final objectives; i.e., growth, and controlling inflation in India. The methodological tool used is testing for Granger Causality in the frequency domain as developed by Lemmens et al. (2008, and monetary policy has been proxied by the weighted average call money rate. In view of the fact that output gap is one of the determinants of future inflation, an attempt has also been made to study the causal relationship between output gap and inflation. The results of empirical estimation show a bi-directional causality between policy rate and inflation and between policy rate and output, which implies that the monetary authorities in India were equally concerned about inflation and output growth when determining policy. Furthermore, any attempt to control inflation affects output with the same or even greater magnitude than inflation, thereby damaging the growth process. The relationship between output gap and inflation was found to be positive, as reported in earlier studies for India. Furthermore, the output gap causes inflation only in the short-tomediumrun.

  13. S-Band AlGaN/GaN power amplifier MMIC with over 20 Watt output power

    NARCIS (Netherlands)

    van Heijningen, M; Visser, G.C.; Wurfl, J.; van Vliet, Frank Edward

    2008-01-01

    Abstract This paper presents the design of an S-band HPA MMIC in AlGaN/GaN CPW technology for radar TR-module application. The trade-offs of using an MMIC solution versus discrete power devices are discussed. The MMIC shows a maximum output power of 38 Watt at 37% Power Added Efficiency at 3.1 GHz.

  14. Enhanced performance CCD output amplifier

    Science.gov (United States)

    Dunham, Mark E.; Morley, David W.

    1996-01-01

    A low-noise FET amplifier is connected to amplify output charge from a che coupled device (CCD). The FET has its gate connected to the CCD in common source configuration for receiving the output charge signal from the CCD and output an intermediate signal at a drain of the FET. An intermediate amplifier is connected to the drain of the FET for receiving the intermediate signal and outputting a low-noise signal functionally related to the output charge signal from the CCD. The amplifier is preferably connected as a virtual ground to the FET drain. The inherent shunt capacitance of the FET is selected to be at least equal to the sum of the remaining capacitances.

  15. Recent advances in the development of high average power induction accelerators for industrial and environmental applications

    International Nuclear Information System (INIS)

    Neau, E.L.

    1994-01-01

    Short-pulse accelerator technology developed during the early 1960's through the late 1980's is being extended to high average power systems capable of use in industrial and environmental applications. Processes requiring high dose levels and/or high volume throughput will require systems with beam power levels from several hundreds of kilowatts to megawatts. Beam accelerating potentials can range from less than 1 MeV to as much as 10 MeV depending on the type of beam, depth of penetration required, and the density of the product being treated. This paper addresses the present status of a family of high average power systems, with output beam power levels up to 200 kW, now in operation that use saturable core switches to achieve output pulse widths of 50 to 80 nanoseconds. Inductive adders and field emission cathodes are used to generate beams of electrons or x-rays at up to 2.5 MeV over areas of 1000 cm 2 . Similar high average power technology is being used at ≤ 1 MeV to drive repetitive ion beam sources for treatment of material surfaces over 100's of cm 2

  16. Multicore PSO Operation for Maximum Power Point Tracking of a Distributed Photovoltaic System under Partially Shading Condition

    Directory of Open Access Journals (Sweden)

    Ru-Min Chao

    2016-01-01

    Full Text Available This paper identifies the partial shading problem of a PV module using the one-diode model and simulating the characteristics exhibiting multiple-peak power output condition that is similar to a PV array. A modified particle swarm optimization (PSO algorithm based on the suggested search-agent deployment, retracking condition, and multicore operation is proposed in order to continuously locate the global maximum power point for the PV system. Partial shading simulation results for up to 16 modules in series/parallel formats are presented. A distributed PV system consisting of up to 8 a-silicon thin film PV panels and also having a dedicated DC/DC buck converter on each of the modules is tested. The converter reaches its steady state voltage output in 10 ms. However for MPPT operation, voltage, and current measurement interval is set to 20 ms to avoid unnecessary noise from the entire electric circuit. Based on the simulation and experiment results, each core of the proposed PSO operation should control no more than 4 PV modules in order to have the maximum tracking accuracy and minimum overall tracking time. Tracking for the global maximum power point of a distributed PV system under various partial shading conditions can be done within 1.3 seconds.

  17. Determination of the diagnostic x-ray tube practical peak voltage (PPV) from average or average peak voltage measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hourdakis, C J, E-mail: khour@gaec.gr [Ionizing Radiation Calibration Laboratory-Greek Atomic Energy Commission, PO Box 60092, 15310 Agia Paraskevi, Athens, Attiki (Greece)

    2011-04-07

    The practical peak voltage (PPV) has been adopted as the reference measuring quantity for the x-ray tube voltage. However, the majority of commercial kV-meter models measure the average peak, U-bar{sub P}, the average, U-bar, the effective, U{sub eff} or the maximum peak, U{sub P} tube voltage. This work proposed a method for determination of the PPV from measurements with a kV-meter that measures the average U-bar or the average peak, U-bar{sub p} voltage. The kV-meter reading can be converted to the PPV by applying appropriate calibration coefficients and conversion factors. The average peak k{sub PPV,kVp} and the average k{sub PPV,Uav} conversion factors were calculated from virtual voltage waveforms for conventional diagnostic radiology (50-150 kV) and mammography (22-35 kV) tube voltages and for voltage ripples from 0% to 100%. Regression equation and coefficients provide the appropriate conversion factors at any given tube voltage and ripple. The influence of voltage waveform irregularities, like 'spikes' and pulse amplitude variations, on the conversion factors was investigated and discussed. The proposed method and the conversion factors were tested using six commercial kV-meters at several x-ray units. The deviations between the reference and the calculated - according to the proposed method - PPV values were less than 2%. Practical aspects on the voltage ripple measurement were addressed and discussed. The proposed method provides a rigorous base to determine the PPV with kV-meters from U-bar{sub p} and U-bar measurement. Users can benefit, since all kV-meters, irrespective of their measuring quantity, can be used to determine the PPV, complying with the IEC standard requirements.

  18. Effects of countermovement depth on kinematic and kinetic patterns of maximum vertical jumps.

    Science.gov (United States)

    Mandic, Radivoj; Jakovljevic, Sasa; Jaric, Slobodan

    2015-04-01

    Although maximum height (H(max)), muscle force (F), and power output (P), have been routinely obtained from maximum vertical jumps for various purposes, a possible role of the countermovement depth (H(cmd)) on the same variables remains largely unexplored. Here we hypothesized that (1) the optimum H(cmd) for maximizing H(max) exists, while (2) an increase in H(cmd) would be associated with a decrease in both F and P. Professional male basketball players (N=11) preformed maximum countermovement jumps with and without arm swing while varying H(cmd)±25 cm from its preferred value. Although regression models revealed a presence of optimum H(cmd) for maximizing H(max), H(max) revealed only small changes within a wide range of H(cmd). The preferred H(cmd) was markedly below its optimum value (p vertical jumps should be taken with caution since both of them could be markedly confounded by H(cmd). Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Relation between Peak Power Output in Sprint Cycling and Maximum Voluntary Isometric Torque Production.

    Science.gov (United States)

    Kordi, Mehdi; Goodall, Stuart; Barratt, Paul; Rowley, Nicola; Leeder, Jonathan; Howatson, Glyn

    2017-08-01

    From a cycling paradigm, little has been done to understand the relationships between maximal isometric strength of different single joint lower body muscle groups and their relation with, and ability to predict PPO and how they compare to an isometric cycling specific task. The aim of this study was to establish relationships between maximal voluntary torque production from isometric single-joint and cycling specific tasks and assess their ability to predict PPO. Twenty male trained cyclists participated in this study. Peak torque was measured by performing maximum voluntary contractions (MVC) of knee extensors, knee flexors, dorsi flexors and hip extensors whilst instrumented cranks measured isometric peak torque from MVC when participants were in their cycling specific position (ISOCYC). A stepwise regression showed that peak torque of the knee extensors was the only significant predictor of PPO when using SJD and accounted for 47% of the variance. However, when compared to ISOCYC, the only significant predictor of PPO was ISOCYC, which accounted for 77% of the variance. This suggests that peak torque of the knee extensors was the best single-joint predictor of PPO in sprint cycling. Furthermore, a stronger prediction can be made from a task specific isometric task. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Evaluation of statistically downscaled GCM output as input for hydrological and stream temperature simulation in the Apalachicola–Chattahoochee–Flint River Basin (1961–99)

    Science.gov (United States)

    Hay, Lauren E.; LaFontaine, Jacob H.; Markstrom, Steven

    2014-01-01

    The accuracy of statistically downscaled general circulation model (GCM) simulations of daily surface climate for historical conditions (1961–99) and the implications when they are used to drive hydrologic and stream temperature models were assessed for the Apalachicola–Chattahoochee–Flint River basin (ACFB). The ACFB is a 50 000 km2 basin located in the southeastern United States. Three GCMs were statistically downscaled, using an asynchronous regional regression model (ARRM), to ⅛° grids of daily precipitation and minimum and maximum air temperature. These ARRM-based climate datasets were used as input to the Precipitation-Runoff Modeling System (PRMS), a deterministic, distributed-parameter, physical-process watershed model used to simulate and evaluate the effects of various combinations of climate and land use on watershed response. The ACFB was divided into 258 hydrologic response units (HRUs) in which the components of flow (groundwater, subsurface, and surface) are computed in response to climate, land surface, and subsurface characteristics of the basin. Daily simulations of flow components from PRMS were used with the climate to simulate in-stream water temperatures using the Stream Network Temperature (SNTemp) model, a mechanistic, one-dimensional heat transport model for branched stream networks.The climate, hydrology, and stream temperature for historical conditions were evaluated by comparing model outputs produced from historical climate forcings developed from gridded station data (GSD) versus those produced from the three statistically downscaled GCMs using the ARRM methodology. The PRMS and SNTemp models were forced with the GSD and the outputs produced were treated as “truth.” This allowed for a spatial comparison by HRU of the GSD-based output with ARRM-based output. Distributional similarities between GSD- and ARRM-based model outputs were compared using the two-sample Kolmogorov–Smirnov (KS) test in combination with descriptive

  1. Area/latency optimized early output asynchronous full adders and relative-timed ripple carry adders.

    Science.gov (United States)

    Balasubramanian, P; Yamashita, S

    2016-01-01

    This article presents two area/latency optimized gate level asynchronous full adder designs which correspond to early output logic. The proposed full adders are constructed using the delay-insensitive dual-rail code and adhere to the four-phase return-to-zero handshaking. For an asynchronous ripple carry adder (RCA) constructed using the proposed early output full adders, the relative-timing assumption becomes necessary and the inherent advantages of the relative-timed RCA are: (1) computation with valid inputs, i.e., forward latency is data-dependent, and (2) computation with spacer inputs involves a bare minimum constant reverse latency of just one full adder delay, thus resulting in the optimal cycle time. With respect to different 32-bit RCA implementations, and in comparison with the optimized strong-indication, weak-indication, and early output full adder designs, one of the proposed early output full adders achieves respective reductions in latency by 67.8, 12.3 and 6.1 %, while the other proposed early output full adder achieves corresponding reductions in area by 32.6, 24.6 and 6.9 %, with practically no power penalty. Further, the proposed early output full adders based asynchronous RCAs enable minimum reductions in cycle time by 83.4, 15, and 8.8 % when considering carry-propagation over the entire RCA width of 32-bits, and maximum reductions in cycle time by 97.5, 27.4, and 22.4 % for the consideration of a typical carry chain length of 4 full adder stages, when compared to the least of the cycle time estimates of various strong-indication, weak-indication, and early output asynchronous RCAs of similar size. All the asynchronous full adders and RCAs were realized using standard cells in a semi-custom design fashion based on a 32/28 nm CMOS process technology.

  2. The use of cardiac output monitoring to guide the administration of intravenous fluid during hyperthermic intraperitoneal chemotherapy.

    Science.gov (United States)

    Thanigaimani, K; Mohamed, F; Cecil, T; Moran, B J; Bell, J

    2013-12-01

    The optimal strategy for intravenous (IV) fluid management during administration of hyperthermic intraperitoneal chemotherapy (HIPEC) is unclear. In this prospective study we describe the use of a LiDCOrapid™ (LiDCO, Cambridge, UK) cardiac output monitor to guide IV fluid management during cytoreductive surgery (CRS) with HIPEC. The aim of this study was to determine whether cardiac output monitoring will allow close maintenance of physiological parameters during the HIPEC phase. Twenty-five patients who underwent CRS combined with HIPEC were included in the study. Intra-operative IV fluid boluses were titrated using parameters measured by the LiDCOrapid™ monitor. Stroke volume variation was maintained below 10% with fluid boluses and mean arterial pressure was maintained within 20% of the baseline figure with vasopressors. There was no significant change in heart rate and cardiac output. The systemic vascular resistance dropped from an average of 966 dyn.s/cm-5 to 797 dyn s/cm(5) at 60 min during the HIPEC phase (P = 0.62) despite an increase in the dose of phenylepherine. The average total volume of fluid given was 748 ml in the first 30 min and 630 ml in the second 30 min with an average urine output of 307 and 445 ml, respectively. The change in lactate levels was not statistically or clinically significant. LiDCOrapid™ is an effective noninvasive tool for guiding fluid management in this population. It allows the anaesthesiologist to maintain tight control of essential physiological parameters during a phase of the procedure in which there is a risk of renal injury. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland.

  3. Governmentally amplified output volatility

    Science.gov (United States)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  4. The effect of a transient thermal lens on the Nd:YVO4 laser output

    International Nuclear Information System (INIS)

    Yi, Jonghoon; Lee, Kangin; Kim, Youngjung; Kwon, Jinhyuk

    2010-01-01

    A Nd:YVO 4 laser was pumped by using a diode laser, which has maximum cw pump power of 1 W. The driving current of the diode laser was modulated to have a square waveform. The Nd:YVO 4 laser output power increased linearly and then saturated when the quasi-cw diode laser pulse was focused on the crystal. When the same diode laser pulse was applied on the crystal, transient thermal lensing in the Nd:YVO 4 crystal was monitored by using a probe beam in a non-lasing condition. The TEM 00 mode diameter of the laser was calculated as a function of the focal length of the thermal lens. The results indicated that transient thermal lensing in the crystal was the main cause of the temporally varying output.

  5. Fungal infection intensity and zoospore output of Atelopus zeteki, a potential acute chytrid supershedder.

    Directory of Open Access Journals (Sweden)

    Graziella V Direnzo

    Full Text Available Amphibians vary in their response to infection by the amphibian-killing chytrid fungus, Batrachochytrium dendrobatidis (Bd. Highly susceptible species are the first to decline and/or disappear once Bd arrives at a site. These competent hosts likely facilitate Bd proliferation because of ineffective innate and/or acquired immune defenses. We show that Atelopus zeteki, a highly susceptible species that has undergone substantial population declines throughout its range, rapidly and exponentially increases skin Bd infection intensity, achieving intensities that are several orders of magnitude greater than most other species reported. We experimentally infected individuals that were never exposed to Bd (n = 5 or previously exposed to an attenuated Bd strain (JEL427-P39; n = 3. Within seven days post-inoculation, the average Bd infection intensity was 18,213 zoospores (SE: 9,010; range: 0 to 66,928. Both average Bd infection intensity and zoospore output (i.e., the number of zoospores released per minute by an infected individual increased exponentially until time of death (t50 = 7.018, p<0.001, t46 = 3.164, p = 0.001, respectively. Mean Bd infection intensity and zoospore output at death were 4,334,422 zoospores (SE: 1,236,431 and 23.55 zoospores per minute (SE: 22.78, respectively, with as many as 9,584,158 zoospores on a single individual. The daily percent increases in Bd infection intensity and zoospore output were 35.4% (SE: 0.05 and 13.1% (SE: 0.04, respectively. We also found that Bd infection intensity and zoospore output were positively correlated (t43 = 3.926, p<0.001. All animals died between 22 and 33 days post-inoculation (mean: 28.88; SE: 1.58. Prior Bd infection had no effect on survival, Bd infection intensity, or zoospore output. We conclude that A. zeteki, a highly susceptible amphibian species, may be an acute supershedder. Our results can inform epidemiological models to estimate Bd outbreak probability, especially as they relate

  6. Entanglement in random pure states: spectral density and average von Neumann entropy

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Santosh; Pandey, Akhilesh, E-mail: skumar.physics@gmail.com, E-mail: ap0700@mail.jnu.ac.in [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)

    2011-11-04

    Quantum entanglement plays a crucial role in quantum information, quantum teleportation and quantum computation. The information about the entanglement content between subsystems of the composite system is encoded in the Schmidt eigenvalues. We derive here closed expressions for the spectral density of Schmidt eigenvalues for all three invariant classes of random matrix ensembles. We also obtain exact results for average von Neumann entropy. We find that maximum average entanglement is achieved if the system belongs to the symplectic invariant class. (paper)

  7. Compact and accurate linear and nonlinear autoregressive moving average model parameter estimation using laguerre functions

    DEFF Research Database (Denmark)

    Chon, K H; Cohen, R J; Holstein-Rathlou, N H

    1997-01-01

    A linear and nonlinear autoregressive moving average (ARMA) identification algorithm is developed for modeling time series data. The algorithm uses Laguerre expansion of kernals (LEK) to estimate Volterra-Wiener kernals. However, instead of estimating linear and nonlinear system dynamics via moving...... average models, as is the case for the Volterra-Wiener analysis, we propose an ARMA model-based approach. The proposed algorithm is essentially the same as LEK, but this algorithm is extended to include past values of the output as well. Thus, all of the advantages associated with using the Laguerre...

  8. Controlling output pulse and prepulse in a resonant microwave pulse compressor

    International Nuclear Information System (INIS)

    Shlapakovski, A.; Artemenko, S.; Chumerin, P.; Yushkov, Yu.

    2013-01-01

    A resonant microwave pulse compressor with a waveguide H-plane-tee-based energy extraction unit was studied in terms of its capability to produce output pulses that comprise a low-power long-duration (prepulse) and a high-power short-duration part. The application of such combined pulses with widely variable prepulse and high-power pulse power and energy ratios is of interest in the research area of electronic hardware vulnerability. The characteristics of output radiation pulses are controlled by the variation of the H-plane tee transition attenuation at the stage of microwave energy storage in the compressor cavity. Results of theoretical estimations of the parameters tuning range and experimental investigations of the prototype S-band compressor (1.5 MW, 12 ns output pulse; ∼13.2 dB gain) are presented. The achievable maximum in the prepulse power is found to be about half the power of the primary microwave source. It has been shown that the energy of the prepulse becomes comparable with that of the short-duration (nanosecond) pulse, while the power of the latter decreases insignificantly. The possible range of variation of the prepulse power and energy can be as wide as 40 dB. In the experiments, the prepulse level control within the range of ∼10 dB was demonstrated.

  9. Trajectory averaging for stochastic approximation MCMC algorithms

    KAUST Repository

    Liang, Faming

    2010-10-01

    The subject of stochastic approximation was founded by Robbins and Monro [Ann. Math. Statist. 22 (1951) 400-407]. After five decades of continual development, it has developed into an important area in systems control and optimization, and it has also served as a prototype for the development of adaptive algorithms for on-line estimation and control of stochastic systems. Recently, it has been used in statistics with Markov chain Monte Carlo for solving maximum likelihood estimation problems and for general simulation and optimizations. In this paper, we first show that the trajectory averaging estimator is asymptotically efficient for the stochastic approximation MCMC (SAMCMC) algorithm under mild conditions, and then apply this result to the stochastic approximation Monte Carlo algorithm [Liang, Liu and Carroll J. Amer. Statist. Assoc. 102 (2007) 305-320]. The application of the trajectory averaging estimator to other stochastic approximationMCMC algorithms, for example, a stochastic approximation MLE algorithm for missing data problems, is also considered in the paper. © Institute of Mathematical Statistics, 2010.

  10. Classic maximum entropy recovery of the average joint distribution of apparent FRET efficiency and fluorescence photons for single-molecule burst measurements.

    Science.gov (United States)

    DeVore, Matthew S; Gull, Stephen F; Johnson, Carey K

    2012-04-05

    We describe a method for analysis of single-molecule Förster resonance energy transfer (FRET) burst measurements using classic maximum entropy. Classic maximum entropy determines the Bayesian inference for the joint probability describing the total fluorescence photons and the apparent FRET efficiency. The method was tested with simulated data and then with DNA labeled with fluorescent dyes. The most probable joint distribution can be marginalized to obtain both the overall distribution of fluorescence photons and the apparent FRET efficiency distribution. This method proves to be ideal for determining the distance distribution of FRET-labeled biomolecules, and it successfully predicts the shape of the recovered distributions.

  11. Maximum attainable power density and wall load in tokamaks underlying reactor relevant constraints

    International Nuclear Information System (INIS)

    Borrass, K.; Buende, R.

    1979-09-01

    The characteristic data of tokamaks optimized with respect to their power density or wall load are determined. Reactor relevant constraints are imposed, such as a fixed plant net power output, a fixed blanket thickness and the dependence of the maximum toroidal field on the geometry and conductor material. The impact of finite burn times is considered. Various scaling laws of the toroidal beta with the aspect ratio are discussed. (orig.) 891 GG/orig. 892 RDG [de

  12. Contribution of population growth to per capita income and sectoral output growth in Japan, 1880-1970.

    Science.gov (United States)

    Yamaguchi, M; Kennedy, G

    1984-09-01

    The authors measured the positive and negative contributions of population and labor force growth to the growth of per capita income and sectoral output in Japan in the 1880-1970 period. A 2-sector growth accounting model that treats population and labor growth as separate variables was used. 3 alternative methods were used: the Residual method, the Verdoorn method, and the factor augmenting rate method. The total contribution of population cum labor growth to per capita income growth tended to be negative in the 1880-1930 period and positive in the 1930-40 and 1950-70. Over the 1880-1970 period as a whole, population cum labor growth made a positive contribution to per capita income growth under the Residual method (0.35%/year), the factor augmenting rate method (0.29%/year), and the Verdoorn method (0.01%/year). In addition, population cum labor growth contributed positively to sectoral output growth. The average contribution to agricultural output growth ranged from 1.03% (Verdoorn) - 1.46%/year (factor augmenting rate), while the average contribution to nonagricultural output growth ranged from 1.22% (Verdoorn) - 1.60%/year (Residual). Although these results are dependent on the model used, the fact that all 3 methods yielded consistent results suggests that population cum labor growth did make a positive contribution to per capita income and sectoral output growth in Japan. These findings imply that in economies where the rate of technical change in agricultural and nonagricultural sectors exceeds population growth, policies that reduce agricultural elasticities may be preferable; on the other hand, policies that reduce agricultural elasticities are to be avoided in economies with low rates of technical change. Moreover, in the early stages of economic development, policies that increase agricultural income and price elasticities should be considered.

  13. Determination of the 4 mm Gamma Knife helmet relative output factor using a variety of detectors

    International Nuclear Information System (INIS)

    Tsai, J.-S.; Rivard, Mark J.; Engler, Mark J.; Mignano, John E.; Wazer, David E.; Shucart, William A.

    2003-01-01

    Though the 4 mm Gamma Knife helmet is used routinely, there is disagreement in the Gamma Knife users community on the value of the 4 mm helmet relative output factor. A range of relative output factors is used, and this variation may impair observations of dose response and optimization of prescribed dose. To study this variation, measurements were performed using the following radiation detectors: silicon diode, diamond detector, radiographic film, radiochromic film, and TLD cubes. To facilitate positioning of the silicon diode and diamond detector, a three-dimensional translation micrometer was used to iteratively determine the position of maximum detector response. Positioning of the films and TLDs was accomplished by manufacturing custom holders for each technique. Results from all five measurement techniques indicate that the 4 mm helmet relative output factor is 0.868±0.014. Within the experimental uncertainties, this value is in good agreement with results obtained by other investigators using diverse techniques

  14. Performance characteristics and parametric choices of a solar thermophotovoltaic cell at the maximum efficiency

    International Nuclear Information System (INIS)

    Dong, Qingchun; Liao, Tianjun; Yang, Zhimin; Chen, Xiaohang; Chen, Jincan

    2017-01-01

    Graphical abstract: The overall model of the solar thermophotovoltaic cell (STPVC) composed of an optical lens, an absorber, an emitter, and a photovoltaic (PV) cell with an integrated back-side reflector is updated to include various irreversible losses. - Highlights: • A new model of the irreversible solar thermophotovoltaic system is proposed. • The material and structure parameters of the system are considered. • The performance characteristics at the maximum efficiency are revealed. • The optimal values of key parameters are determined. • The system can obtain a large efficiency under a relative low concentration ratio. - Abstract: The overall model of the solar thermophotovoltaic cell (STPVC) composed of an optical lens, an absorber, an emitter, and a photovoltaic (PV) cell with an integrated back-side reflector is updated to include various irreversible losses. The power output and efficiency of the cell are analytically derived. The performance characteristics of the STPVC at the maximum efficiency are revealed. The optimum values of several important parameters, such as the voltage output of the PV cell, the area ratio of the absorber to the emitter, and the band-gap of the semiconductor material, are determined. It is found that under the condition of a relative low concentration ratio, the optimally designed STPVC can obtain a relative large efficiency.

  15. Muscle force output and electromyographic activity in squats with various unstable surfaces.

    Science.gov (United States)

    Saeterbakken, Atle H; Fimland, Marius S

    2013-01-01

    The purpose of the study was to compare force output and muscle activity of leg and trunk muscles in isometric squats executed on stable surface (i.e., floor), power board, BOSU ball, and balance cone. Fifteen healthy men (23.3 ± 2.7 years, mass: 80.5 ± 8.5 kg, height: 1.81 ± 0.09 m) volunteered. The force output and electromyographic (EMG) activities of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, soleus, rectus abdominis, oblique external, and erector spinae were assessed. The order of the surfaces was randomized. One familiarization session was executed before the experimental test. Compared with stable surface (749 ± 222 N), the force output using power board was similar (-7%, p = 0.320) but lower for BOSU ball (-19%, p = 0.003) and balance cone (-24%, p ≤ 0.001). The force output using BOSU ball and balance cone was approximately 13% (p = 0.037) and approximately 18% (p = 0.001) less than the power board. There were similar EMG activities between the surfaces in all muscles except for rectus femoris, in which stable squat provided greater EMG activity than did the other exercises (p = 0.004-0.030). Lower EMG activity was observed in the rectus femoris using balance cone compared with the BOSU ball (p = 0.030). In conclusion, increasing the instability of the surface during maximum effort isometric squats usually maintains the muscle activity of lower-limb and superficial trunk muscles although the force output is reduced. This suggests that unstable surfaces in the squat may be beneficial in rehabilitation and as a part of periodized training programs, because similar muscle activity can be achieved with reduced loads.

  16. [h Index and scientific output of researchers in medicine from the University of Guadalajara, Mexico].

    Science.gov (United States)

    Panduro, Arturo; Ojeda-Granados, Claudia; Rivera, Horacio; Roman, Sonia

    2015-01-01

    To evaluate by the h index the scientific output of researchers from the University of Guadalajara who belong to the Sistema Nacional de Investigadores in the field of Medicine and Health Sciences. Researchers from the University of Guadalajara were selected from the Active SNI Researchers 2013 file. The scientific output of researchers in the fields of Medicine/Health Sciences and Biology/Chemistry was evaluated using the h index estimated by the Scopus website. A sample of capital researchers and Emeritus scientists was taken to perform the same procedure and compare data. The total number of researchers in the University of Guadalajara who are members of the SNI was 711, of which 67.2 % were level I and in less proportion were level II and III. Only 24.2 % of them were classified in the fields of Medicine/Health Sciences and Biology/Chemistry. The average h index value of researchers level I, II and III in Medicine/Health Sciences field was 5.4, 10.5 and 14.5, respectively. Capital and Emeritus scientists had an average h index of 23.4 and 19.8, respectively. The h index measures the quantity and quality of the scientific output and it also avoids bias in the evaluation process. It should be useful for future evaluations of the SNI members and for medical doctors who sign up for the National Academy of Medicine.

  17. SU-E-T-136: Assessment of Seasonal Linear Accelerator Output Variations and Associated Impacts

    International Nuclear Information System (INIS)

    Bartolac, S; Letourneau, D

    2015-01-01

    Purpose: Application of process control theory in quality assurance programs promises to allow earlier identification of problems and potentially better quality in delivery than traditional paradigms based primarily on tolerances and action levels. The purpose of this project was to characterize underlying seasonal variations in linear accelerator output that can be used to improve performance or trigger preemptive maintenance. Methods: Review of runtime plots of daily (6 MV) output data acquired using in house ion chamber based devices over three years and for fifteen linear accelerators of varying make and model were evaluated. Shifts in output due to known interventions with the machines were subtracted from the data to model an uncorrected scenario for each linear accelerator. Observable linear trends were also removed from the data prior to evaluation of periodic variations. Results: Runtime plots of output revealed sinusoidal, seasonal variations that were consistent across all units, irrespective of manufacturer, model or age of machine. The average amplitude of the variation was on the order of 1%. Peak and minimum variations were found to correspond to early April and September, respectively. Approximately 48% of output adjustments made over the period examined were potentially avoidable if baseline levels had corresponded to the mean output, rather than to points near a peak or valley. Linear trends were observed for three of the fifteen units, with annual increases in output ranging from 2–3%. Conclusion: Characterization of cyclical seasonal trends allows for better separation of potentially innate accelerator behaviour from other behaviours (e.g. linear trends) that may be better described as true out of control states (i.e. non-stochastic deviations from otherwise expected behavior) and could indicate service requirements. Results also pointed to an optimal setpoint for accelerators such that output of machines is maintained within set tolerances

  18. SU-E-T-136: Assessment of Seasonal Linear Accelerator Output Variations and Associated Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Bartolac, S; Letourneau, D [Princess Margaret Cancer Centre, Toronto, Ontario (Canada); University of Toronto, Toronto, Ontario (Canada)

    2015-06-15

    Purpose: Application of process control theory in quality assurance programs promises to allow earlier identification of problems and potentially better quality in delivery than traditional paradigms based primarily on tolerances and action levels. The purpose of this project was to characterize underlying seasonal variations in linear accelerator output that can be used to improve performance or trigger preemptive maintenance. Methods: Review of runtime plots of daily (6 MV) output data acquired using in house ion chamber based devices over three years and for fifteen linear accelerators of varying make and model were evaluated. Shifts in output due to known interventions with the machines were subtracted from the data to model an uncorrected scenario for each linear accelerator. Observable linear trends were also removed from the data prior to evaluation of periodic variations. Results: Runtime plots of output revealed sinusoidal, seasonal variations that were consistent across all units, irrespective of manufacturer, model or age of machine. The average amplitude of the variation was on the order of 1%. Peak and minimum variations were found to correspond to early April and September, respectively. Approximately 48% of output adjustments made over the period examined were potentially avoidable if baseline levels had corresponded to the mean output, rather than to points near a peak or valley. Linear trends were observed for three of the fifteen units, with annual increases in output ranging from 2–3%. Conclusion: Characterization of cyclical seasonal trends allows for better separation of potentially innate accelerator behaviour from other behaviours (e.g. linear trends) that may be better described as true out of control states (i.e. non-stochastic deviations from otherwise expected behavior) and could indicate service requirements. Results also pointed to an optimal setpoint for accelerators such that output of machines is maintained within set tolerances

  19. Performance Comparison between ĆUK and SEPIC Converters for Maximum Power Point Tracking Using Incremental Conductance Technique in Solar Power Applications

    OpenAIRE

    James Dunia; Bakari M. M. Mwinyiwiwa

    2013-01-01

    Photovoltaic (PV) energy is one of the most important energy resources since it is clean, pollution free, and endless. Maximum Power Point Tracking (MPPT) is used in photovoltaic (PV) systems to maximize the photovoltaic output power, irrespective the variations of temperature and radiation conditions. This paper presents a comparison between Ćuk and SEPIC converter in maximum power point tracking (MPPT) of photovoltaic (PV) system. In the paper, advantages and disadvantages of both converter...

  20. Book Trade Research and Statistics. Prices of U.S. and Foreign Published Materials; Book Title Output and Average Prices: 2001 Final and 2002 Preliminary Figures; Book Sales Statistics, 2002: AAP Preliminary Estimates; U.S. Book Exports and Imports:2002; Number of Book Outlets in the United States and Canada; Review Media Statistics.

    Science.gov (United States)

    Sullivan, Sharon G.; Grabois, Andrew; Greco, Albert N.

    2003-01-01

    Includes six reports related to book trade statistics, including prices of U.S. and foreign materials; book title output and average prices; book sales statistics; book exports and imports; book outlets in the U.S. and Canada; and numbers of books and other media reviewed by major reviewing publications. (LRW)

  1. The concept of the average stress in the fracture process zone for the search of the crack path

    Directory of Open Access Journals (Sweden)

    Yu.G. Matvienko

    2015-10-01

    Full Text Available The concept of the average stress has been employed to propose the maximum average tangential stress (MATS criterion for predicting the direction of fracture angle. This criterion states that a crack grows when the maximum average tangential stress in the fracture process zone ahead of the crack tip reaches its critical value and the crack growth direction coincides with the direction of the maximum average tangential stress along a constant radius around the crack tip. The tangential stress is described by the singular and nonsingular (T-stress terms in the Williams series solution. To demonstrate the validity of the proposed MATS criterion, this criterion is directly applied to experiments reported in the literature for the mixed mode I/II crack growth behavior of Guiting limestone. The predicted directions of fracture angle are consistent with the experimental data. The concept of the average stress has been also employed to predict the surface crack path under rolling-sliding contact loading. The proposed model considers the size and orientation of the initial crack, normal and tangential loading due to rolling–sliding contact as well as the influence of fluid trapped inside the crack by a hydraulic pressure mechanism. The MATS criterion is directly applied to equivalent contact model for surface crack growth on a gear tooth flank.

  2. 915 MHz microwave ablation with high output power in in vivo porcine spleens

    International Nuclear Information System (INIS)

    Gao Yongyan; Wang Yang; Duan Yaqi; Li Chunling; Sun Yuanyuan; Zhang Dakun; Lu Tong; Liang Ping

    2010-01-01

    Objective: The purpose of this study was to evaluate the efficacy of 915 MHz microwave (MW) ablation with high output power in in vivo porcine spleens. Materials and methods: MW ablations were performed in 9 porcine spleens with an internally cooled 915 MHz antenna. Thermocouples were placed at 5, 10, 15, 20 mm away from the antenna to measure temperatures in real-time during MW emission. The energy was applied for 10 min at high output power of 60 W, 70 W or 80 W. Gross specimens were sectioned and measured to determine ablation size. Representative areas were examined by light microscopy and electron microscopy. Coagulation sizes and temperatures were compared among the three power groups. Results: Hematoxylin-eosin staining showed irreversible necrosis in the splenic coagulation area after MW ablation. As the power was increased, long-axis diameter enlarged significantly (p .05). The coagulation size of long-axis and short-axis diameter with 80 W in vivo spleen ablation was 6.43 ± 0.52 and 4.95 ± 0.30 cm, respectively. With the increase of output power, maximum temperatures at 5, 10, 15, 20 mm from the antenna were increased accordingly (p o C respectively. Conclusion: With internally cooled antenna and high output power, 915 MHz MW ablation in the spleen could produce irreversible tissue necrosis of clinical significance. MW ablation may be used as a promising minimally invasive method for the treatment of splenic diseases.

  3. Weakest solar wind of the space age and the current 'MINI' solar maximum

    International Nuclear Information System (INIS)

    McComas, D. J.; Angold, N.; Elliott, H. A.; Livadiotis, G.; Schwadron, N. A.; Smith, C. W.; Skoug, R. M.

    2013-01-01

    The last solar minimum, which extended into 2009, was especially deep and prolonged. Since then, sunspot activity has gone through a very small peak while the heliospheric current sheet achieved large tilt angles similar to prior solar maxima. The solar wind fluid properties and interplanetary magnetic field (IMF) have declined through the prolonged solar minimum and continued to be low through the current mini solar maximum. Compared to values typically observed from the mid-1970s through the mid-1990s, the following proton parameters are lower on average from 2009 through day 79 of 2013: solar wind speed and beta (∼11%), temperature (∼40%), thermal pressure (∼55%), mass flux (∼34%), momentum flux or dynamic pressure (∼41%), energy flux (∼48%), IMF magnitude (∼31%), and radial component of the IMF (∼38%). These results have important implications for the solar wind's interaction with planetary magnetospheres and the heliosphere's interaction with the local interstellar medium, with the proton dynamic pressure remaining near the lowest values observed in the space age: ∼1.4 nPa, compared to ∼2.4 nPa typically observed from the mid-1970s through the mid-1990s. The combination of lower magnetic flux emergence from the Sun (carried out in the solar wind as the IMF) and associated low power in the solar wind points to the causal relationship between them. Our results indicate that the low solar wind output is driven by an internal trend in the Sun that is longer than the ∼11 yr solar cycle, and they suggest that this current weak solar maximum is driven by the same trend.

  4. Energy and output dynamics in Bangladesh

    International Nuclear Information System (INIS)

    Paul, Biru Paksha; Uddin, Gazi Salah

    2011-01-01

    The relationship between energy consumption and output is still ambiguous in the existing literature. The economy of Bangladesh, having spectacular output growth and rising energy demand as well as energy efficiency in recent decades, can be an ideal case for examining energy-output dynamics. We find that while fluctuations in energy consumption do not affect output fluctuations, movements in output inversely affect movements in energy use. The results of Granger causality tests in this respect are consistent with those of innovative accounting that includes variance decompositions and impulse responses. Autoregressive distributed lag models also suggest a role of output in Bangladesh's energy use. Hence, the findings of this study have policy implications for other developing nations where measures for energy conservation and efficiency can be relevant in policymaking.

  5. Phantom and Clinical Study of Differences in Cone Beam Computed Tomographic Registration When Aligned to Maximum and Average Intensity Projection

    Energy Technology Data Exchange (ETDEWEB)

    Shirai, Kiyonori [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Nishiyama, Kinji, E-mail: sirai-ki@mc.pref.osaka.jp [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Katsuda, Toshizo [Department of Radiology, National Cerebral and Cardiovascular Center, Osaka (Japan); Teshima, Teruki; Ueda, Yoshihiro; Miyazaki, Masayoshi; Tsujii, Katsutomo [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan)

    2014-01-01

    Purpose: To determine whether maximum or average intensity projection (MIP or AIP, respectively) reconstructed from 4-dimensional computed tomography (4DCT) is preferred for alignment to cone beam CT (CBCT) images in lung stereotactic body radiation therapy. Methods and Materials: Stationary CT and 4DCT images were acquired with a target phantom at the center of motion and moving along the superior–inferior (SI) direction, respectively. Motion profiles were asymmetrical waveforms with amplitudes of 10, 15, and 20 mm and a 4-second cycle. Stationary CBCT and dynamic CBCT images were acquired in the same manner as stationary CT and 4DCT images. Stationary CBCT was aligned to stationary CT, and the couch position was used as the baseline. Dynamic CBCT was aligned to the MIP and AIP of corresponding amplitudes. Registration error was defined as the SI deviation of the couch position from the baseline. In 16 patients with isolated lung lesions, free-breathing CBCT (FBCBCT) was registered to AIP and MIP (64 sessions in total), and the difference in couch shifts was calculated. Results: In the phantom study, registration errors were within 0.1 mm for AIP and 1.5 to 1.8 mm toward the inferior direction for MIP. In the patient study, the difference in the couch shifts (mean, range) was insignificant in the right-left (0.0 mm, ≤1.0 mm) and anterior–posterior (0.0 mm, ≤2.1 mm) directions. In the SI direction, however, the couch position significantly shifted in the inferior direction after MIP registration compared with after AIP registration (mean, −0.6 mm; ranging 1.7 mm to the superior side and 3.5 mm to the inferior side, P=.02). Conclusions: AIP is recommended as the reference image for registration to FBCBCT when target alignment is performed in the presence of asymmetrical respiratory motion, whereas MIP causes systematic target positioning error.

  6. Phantom and Clinical Study of Differences in Cone Beam Computed Tomographic Registration When Aligned to Maximum and Average Intensity Projection

    International Nuclear Information System (INIS)

    Shirai, Kiyonori; Nishiyama, Kinji; Katsuda, Toshizo; Teshima, Teruki; Ueda, Yoshihiro; Miyazaki, Masayoshi; Tsujii, Katsutomo

    2014-01-01

    Purpose: To determine whether maximum or average intensity projection (MIP or AIP, respectively) reconstructed from 4-dimensional computed tomography (4DCT) is preferred for alignment to cone beam CT (CBCT) images in lung stereotactic body radiation therapy. Methods and Materials: Stationary CT and 4DCT images were acquired with a target phantom at the center of motion and moving along the superior–inferior (SI) direction, respectively. Motion profiles were asymmetrical waveforms with amplitudes of 10, 15, and 20 mm and a 4-second cycle. Stationary CBCT and dynamic CBCT images were acquired in the same manner as stationary CT and 4DCT images. Stationary CBCT was aligned to stationary CT, and the couch position was used as the baseline. Dynamic CBCT was aligned to the MIP and AIP of corresponding amplitudes. Registration error was defined as the SI deviation of the couch position from the baseline. In 16 patients with isolated lung lesions, free-breathing CBCT (FBCBCT) was registered to AIP and MIP (64 sessions in total), and the difference in couch shifts was calculated. Results: In the phantom study, registration errors were within 0.1 mm for AIP and 1.5 to 1.8 mm toward the inferior direction for MIP. In the patient study, the difference in the couch shifts (mean, range) was insignificant in the right-left (0.0 mm, ≤1.0 mm) and anterior–posterior (0.0 mm, ≤2.1 mm) directions. In the SI direction, however, the couch position significantly shifted in the inferior direction after MIP registration compared with after AIP registration (mean, −0.6 mm; ranging 1.7 mm to the superior side and 3.5 mm to the inferior side, P=.02). Conclusions: AIP is recommended as the reference image for registration to FBCBCT when target alignment is performed in the presence of asymmetrical respiratory motion, whereas MIP causes systematic target positioning error

  7. Maximum power point tracking for PV systems under partial shading conditions using current sweeping

    International Nuclear Information System (INIS)

    Tsang, K.M.; Chan, W.L.

    2015-01-01

    Highlights: • A novel approach for tracking the maximum power point of photovoltaic systems. • Able to handle both the uniform insolation and partial shading conditions. • Maximum power point tracking based on current sweeping. - Abstract: Partial shading on photovoltaic (PV) arrays causes multiple peaks on the output power–voltage characteristic curve and local searching technique such as perturb and observe (P&O) method could easily fail in searching for the global maximum. Moreover, existing global searching techniques are still not very satisfactory in terms of speed and implementation complexity. In this paper, a fast global maximum power point (MPPT) tracking method which is using current sweeping for photovoltaic arrays under partial shading conditions is proposed. Unlike conventional approach, the proposed method is current based rather than voltage based. The initial maximum power point will be derived based on a current sweeping test and the maximum power point can be enhanced by a finer local search. The speed of the global search is mainly governed by the apparent time constant of the PV array and the generation of a fast current sweeping test. The fast current sweeping test can easily be realized by a DC/DC boost converter with a very fast current control loop. Experimental results are included to demonstrate the effectiveness of the proposed global searching scheme

  8. Generation and Applications of High Average Power Mid-IR Supercontinuum in Chalcogenide Fibers

    OpenAIRE

    Petersen, Christian Rosenberg

    2016-01-01

    Mid-infrared supercontinuum with up to 54.8 mW average power, and maximum bandwidth of 1.77-8.66 μm is demonstrated as a result of pumping tapered chalcogenide photonic crystal fibers with a MHz parametric source at 4 μm

  9. Using Bayes Model Averaging for Wind Power Forecasts

    Science.gov (United States)

    Preede Revheim, Pål; Beyer, Hans Georg

    2014-05-01

    For operational purposes predictions of the forecasts of the lumped output of groups of wind farms spread over larger geographic areas will often be of interest. A naive approach is to make forecasts for each individual site and sum them up to get the group forecast. It is however well documented that a better choice is to use a model that also takes advantage of spatial smoothing effects. It might however be the case that some sites tends to more accurately reflect the total output of the region, either in general or for certain wind directions. It will then be of interest giving these a greater influence over the group forecast. Bayesian model averaging (BMA) is a statistical post-processing method for producing probabilistic forecasts from ensembles. Raftery et al. [1] show how BMA can be used for statistical post processing of forecast ensembles, producing PDFs of future weather quantities. The BMA predictive PDF of a future weather quantity is a weighted average of the ensemble members' PDFs, where the weights can be interpreted as posterior probabilities and reflect the ensemble members' contribution to overall forecasting skill over a training period. In Revheim and Beyer [2] the BMA procedure used in Sloughter, Gneiting and Raftery [3] were found to produce fairly accurate PDFs for the future mean wind speed of a group of sites from the single sites wind speeds. However, when the procedure was attempted applied to wind power it resulted in either problems with the estimation of the parameters (mainly caused by longer consecutive periods of no power production) or severe underestimation (mainly caused by problems with reflecting the power curve). In this paper the problems that arose when applying BMA to wind power forecasting is met through two strategies. First, the BMA procedure is run with a combination of single site wind speeds and single site wind power production as input. This solves the problem with longer consecutive periods where the input data

  10. Decomposing variation in dairy profitability: the impact of output, inputs, prices, labour and management.

    Science.gov (United States)

    Wilson, P

    2011-08-01

    The UK dairy sector has undergone considerable structural change in recent years, with a decrease in the number of producers accompanied by an increased average herd size and increased concentrate use and milk yields. One of the key drivers to producers remaining in the industry is the profitability of their herds. The current paper adopts a holistic approach to decomposing the variation in dairy profitability through an analysis of net margin data explained by physical input-output measures, milk price variation, labour utilization and managerial behaviours and characteristics. Data are drawn from the Farm Business Survey (FBS) for England in 2007/08 for 228 dairy enterprises. Average yields are 7100 litres/cow/yr, from a herd size of 110 cows that use 0·56 forage ha/cow/yr and 43·2 labour h/cow/yr. An average milk price of 22·57 pence per litre (ppl) produced milk output of £1602/cow/yr, which after accounting for calf sales, herd replacements and quota leasing costs, gave an average dairy output of £1516/cow/yr. After total costs of £1464/cow/yr this left an economic return of £52/cow/yr (0·73 ppl) net margin profit. There is wide variation in performance, with the most profitable (as measured by net margin per cow) quartile of producers achieving 2000 litres/cow/yr more than the least profitable quartile, returning a net margin of £335/cow/yr compared to a loss of £361/cow/yr for the least profitable. The most profitable producers operate larger, higher yielding herds and achieve a greater milk price for their output. In addition, a significantly greater number of the most profitable producers undertake financial benchmarking within their businesses and operate specialist dairy farms. When examining the full data set, the most profitable enterprises included significantly greater numbers of organic producers. The most profitable tend to have a greater reliance on independent technical advice, but this finding is not statistically significant

  11. Emf, maximum power and efficiency of fuel cells

    International Nuclear Information System (INIS)

    Gaggioli, R.A.; Dunbar, W.R.

    1990-01-01

    This paper discusses the ideal voltage of steady-flow fuel cells usually expressed by Emf = -ΔG/nF where ΔG is the Gibbs free energy of reaction for the oxidation of the fuel at the supposed temperature of operation of the cell. Furthermore, the ideal power of the cell is expressed as the product of the fuel flow rate with this emf, and the efficiency of a real fuel cell, sometimes called the Gibbs efficiency, is defined as the ratio of the actual power output to this ideal power. Such viewpoints are flawed in several respects. While it is true that if a cell operates isothermally the maximum conceivable work output is equal to the difference between the Gibbs free energy of the incoming reactants and that of the leaving products, nevertheless, even if the cell operates isothermally, the use of the conventional ΔG of reaction assumes that the products of reaction leave separately from one another (and from any unused fuel), and when ΔS of reaction is positive it assumes that a free heat source exists at the operating temperature, whereas if ΔS is negative it neglects the potential power which theoretically could be obtained form the heat released during oxidation. Moreover, the usual cell does not operate isothermally but (virtually) adiabatically

  12. Surface morphology and surface energy of anode materials influence power outputs in a multi-channel mediatorless bio-photovoltaic (BPV) system.

    Science.gov (United States)

    Bombelli, Paolo; Zarrouati, Marie; Thorne, Rebecca J; Schneider, Kenneth; Rowden, Stephen J L; Ali, Akin; Yunus, Kamran; Cameron, Petra J; Fisher, Adrian C; Ian Wilson, D; Howe, Christopher J; McCormick, Alistair J

    2012-09-21

    Bio-photovoltaic cells (BPVs) are a new photo-bio-electrochemical technology for harnessing solar energy using the photosynthetic activity of autotrophic organisms. Currently power outputs from BPVs are generally low and suffer from low efficiencies. However, a better understanding of the electrochemical interactions between the microbes and conductive materials will be likely to lead to increased power yields. In the current study, the fresh-water, filamentous cyanobacterium Pseudanabaena limnetica (also known as Oscillatoria limnetica) was investigated for exoelectrogenic activity. Biofilms of P. limnetica showed a significant photo response during light-dark cycling in BPVs under mediatorless conditions. A multi-channel BPV device was developed to compare quantitatively the performance of photosynthetic biofilms of this species using a variety of different anodic conductive materials: indium tin oxide-coated polyethylene terephthalate (ITO), stainless steel (SS), glass coated with a conductive polymer (PANI), and carbon paper (CP). Although biofilm growth rates were generally comparable on all materials tested, the amplitude of the photo response and achievable maximum power outputs were significantly different. ITO and SS demonstrated the largest photo responses, whereas CP showed the lowest power outputs under both light and dark conditions. Furthermore, differences in the ratios of light : dark power outputs indicated that the electrochemical interactions between photosynthetic microbes and the anode may differ under light and dark conditions depending on the anodic material used. Comparisons between BPV performances and material characteristics revealed that surface roughness and surface energy, particularly the ratio of non-polar to polar interactions (the CQ ratio), may be more important than available surface area in determining biocompatibility and maximum power outputs in microbial electrochemical systems. Notably, CP was readily outperformed by all

  13. Use of medium-range numerical weather prediction model output to produce forecasts of streamflow

    Science.gov (United States)

    Clark, M.P.; Hay, L.E.

    2004-01-01

    This paper examines an archive containing over 40 years of 8-day atmospheric forecasts over the contiguous United States from the NCEP reanalysis project to assess the possibilities for using medium-range numerical weather prediction model output for predictions of streamflow. This analysis shows the biases in the NCEP forecasts to be quite extreme. In many regions, systematic precipitation biases exceed 100% of the mean, with temperature biases exceeding 3??C. In some locations, biases are even higher. The accuracy of NCEP precipitation and 2-m maximum temperature forecasts is computed by interpolating the NCEP model output for each forecast day to the location of each station in the NWS cooperative network and computing the correlation with station observations. Results show that the accuracy of the NCEP forecasts is rather low in many areas of the country. Most apparent is the generally low skill in precipitation forecasts (particularly in July) and low skill in temperature forecasts in the western United States, the eastern seaboard, and the southern tier of states. These results outline a clear need for additional processing of the NCEP Medium-Range Forecast Model (MRF) output before it is used for hydrologic predictions. Techniques of model output statistics (MOS) are used in this paper to downscale the NCEP forecasts to station locations. Forecasted atmospheric variables (e.g., total column precipitable water, 2-m air temperature) are used as predictors in a forward screening multiple linear regression model to improve forecasts of precipitation and temperature for stations in the National Weather Service cooperative network. This procedure effectively removes all systematic biases in the raw NCEP precipitation and temperature forecasts. MOS guidance also results in substantial improvements in the accuracy of maximum and minimum temperature forecasts throughout the country. For precipitation, forecast improvements were less impressive. MOS guidance increases

  14. Implementation of Maximum Power Point Tracking (MPPT) Solar Charge Controller using Arduino

    Science.gov (United States)

    Abdelilah, B.; Mouna, A.; KouiderM’Sirdi, N.; El Hossain, A.

    2018-05-01

    the platform Arduino with a number of sensors standard can be used as components of an electronic system for acquiring measures and controls. This paper presents the design of a low-cost and effective solar charge controller. This system includes several elements such as the solar panel converter DC/DC, battery, circuit MPPT using Microcontroller, sensors, and the MPPT algorithm. The MPPT (Maximum Power Point Tracker) algorithm has been implemented using an Arduino Nano with the preferred program. The voltage and current of the Panel are taken where the program implemented will work and using this algorithm that MPP will be reached. This paper provides details on the solar charge control device at the maximum power point. The results include the change of the duty cycle with the change in load and thus mean the variation of the buck converter output voltage and current controlled by the MPPT algorithm.

  15. Effects of bruxism on the maximum bite force

    Directory of Open Access Journals (Sweden)

    Todić Jelena T.

    2017-01-01

    Full Text Available Background/Aim. Bruxism is a parafunctional activity of the masticatory system, which is characterized by clenching or grinding of teeth. The purpose of this study was to determine whether the presence of bruxism has impact on maximum bite force, with particular reference to the potential impact of gender on bite force values. Methods. This study included two groups of subjects: without and with bruxism. The presence of bruxism in the subjects was registered using a specific clinical questionnaire on bruxism and physical examination. The subjects from both groups were submitted to the procedure of measuring the maximum bite pressure and occlusal contact area using a single-sheet pressure-sensitive films (Fuji Prescale MS and HS Film. Maximal bite force was obtained by multiplying maximal bite pressure and occlusal contact area values. Results. The average values of maximal bite force were significantly higher in the subjects with bruxism compared to those without bruxism (p 0.01. Maximal bite force was significantly higher in the males compared to the females in all segments of the research. Conclusion. The presence of bruxism influences the increase in the maximum bite force as shown in this study. Gender is a significant determinant of bite force. Registration of maximum bite force can be used in diagnosing and analysing pathophysiological events during bruxism.

  16. Cardiac output measurement

    Directory of Open Access Journals (Sweden)

    Andreja Möller Petrun

    2014-02-01

    Full Text Available In recent years, developments in the measuring of cardiac output and other haemodynamic variables are focused on the so-called minimally invasive methods. The aim of these methods is to simplify the management of high-risk and haemodynamically unstable patients. Due to the need of invasive approach and the possibility of serious complications the use of pulmonary artery catheter has decreased. This article describes the methods for measuring cardiac output, which are based on volume measurement (Fick method, indicator dilution method, pulse wave analysis, Doppler effect, and electrical bioimpedance.

  17. Non-linear control of the output stage of a solar microinverter

    Science.gov (United States)

    Lopez-Santos, Oswaldo; Garcia, Germain; Martinez-Salamero, Luis; Avila-Martinez, Juan C.; Seguier, Lionel

    2017-01-01

    This paper presents a proposal to control the output stage of a two-stage solar microinverter to inject real power into the grid. The input stage of the microinverter is used to extract the maximum available power of a photovoltaic module enforcing a power source behavior in the DC-link to feed the output stage. The work here reported is devoted to control a grid-connected power source inverter with a high power quality level at the grid side ensuring the power balance of the microinverter regulating the voltage of the DC-link. The proposed control is composed of a sinusoidal current reference generator and a cascade type controller composed by a current tracking loop and a voltage regulation loop. The current reference is obtained using a synchronized generator based on phase locked loop (PLL) which gives the shape, the frequency and phase of the current signal. The amplitude of the reference is obtained from a simple controller regulating the DC-link voltage. The tracking of the current reference is accomplished by means of a first-order sliding mode control law. The solution takes advantage of the rapidity and inherent robustness of the sliding mode current controller allowing a robust behavior in the regulation of the DC-link using a simple linear controller. The analytical expression to determine the power quality indicators of the micro-inverter's output is theoretically solved giving expressions relating the converter parameters. The theoretical approach is validated using simulation and experimental results.

  18. Electron emission of cathode holder of vacuum diode of an intense electron-beam accelerator and its effect on the output voltage

    OpenAIRE

    Xin-Bing Cheng; Jin-Liang Liu; Hong-Bo Zhang; Zhi-Qiang Hong; Bao-Liang Qian

    2011-01-01

    The vacuum diode which is used to generate relativistic electron beams is one of the most important parts of a pulsed-power modulator. In this paper, the electron emission of cathode holder of a vacuum diode and its effect on the output voltage is investigated by experiments on an intense electron-beam accelerator with 180 ns full width at half maximum and 200–500 kV output voltage. First, the field emission is analyzed and the electric field of the vacuum chamber is calculated. Then, the fla...

  19. Probabilistic Output Analysis by Program Manipulation

    DEFF Research Database (Denmark)

    Rosendahl, Mads; Kirkeby, Maja Hanne

    2015-01-01

    The aim of a probabilistic output analysis is to derive a probability distribution of possible output values for a program from a probability distribution of its input. We present a method for performing static output analysis, based on program transformation techniques. It generates a probability...

  20. Development of an optical resonator with high-efficient output coupler for the JAERI far-infrared free-electron laser

    International Nuclear Information System (INIS)

    Nagai, Ryoji; Hajima, Ryoichi; Nishimori, Nobuyuki; Sawamura, Masaru; Kikuzawa, Nobuhiro; Shizuma, Toshiyuki; Minehara, Eisuke

    2001-01-01

    An optical resonator with a high-efficient output coupler was developed for the JAERI far-infrared free-electron laser. The optical resonator is symmetrical near-concentric geometry with an insertable scraper output coupler. As a result of the development of the optical resonator, the JAERI-FEL has been successfully, lased with averaged power over 1 kW. Performance of the optical resonator with the output coupler was evaluated at optical wavelength of 22 μm by using an optical mode calculation code. The output coupling and diffractive loss with a dominant eigen-mode of the resonator were calculated using an iterative computation called Fox-Li procedure. An efficiency factor of the optical resonator was introduced for the evaluation of the optical resonator performance. The efficiency factor was derived by the amount of the output coupling and diffractive loss of the optical resonator. It was found that the optical resonator with the insertable scraper coupler was the most suitable to a high-power and high-efficient far-infrared free-electron laser. (author)

  1. Bistability, non-ergodicity, and inhibition in pairwise maximum-entropy models.

    Science.gov (United States)

    Rostami, Vahid; Porta Mana, PierGianLuca; Grün, Sonja; Helias, Moritz

    2017-10-01

    Pairwise maximum-entropy models have been used in neuroscience to predict the activity of neuronal populations, given only the time-averaged correlations of the neuron activities. This paper provides evidence that the pairwise model, applied to experimental recordings, would produce a bimodal distribution for the population-averaged activity, and for some population sizes the second mode would peak at high activities, that experimentally would be equivalent to 90% of the neuron population active within time-windows of few milliseconds. Several problems are connected with this bimodality: 1. The presence of the high-activity mode is unrealistic in view of observed neuronal activity and on neurobiological grounds. 2. Boltzmann learning becomes non-ergodic, hence the pairwise maximum-entropy distribution cannot be found: in fact, Boltzmann learning would produce an incorrect distribution; similarly, common variants of mean-field approximations also produce an incorrect distribution. 3. The Glauber dynamics associated with the model is unrealistically bistable and cannot be used to generate realistic surrogate data. This bimodality problem is first demonstrated for an experimental dataset from 159 neurons in the motor cortex of macaque monkey. Evidence is then provided that this problem affects typical neural recordings of population sizes of a couple of hundreds or more neurons. The cause of the bimodality problem is identified as the inability of standard maximum-entropy distributions with a uniform reference measure to model neuronal inhibition. To eliminate this problem a modified maximum-entropy model is presented, which reflects a basic effect of inhibition in the form of a simple but non-uniform reference measure. This model does not lead to unrealistic bimodalities, can be found with Boltzmann learning, and has an associated Glauber dynamics which incorporates a minimal asymmetric inhibition.

  2. DFT based spatial multiplexing and maximum ratio transmission for mm-wawe large MIMO

    DEFF Research Database (Denmark)

    Phan-Huy, D.-T.; Tölli, A.; Rajatheva, N.

    2014-01-01

    -SM-MRT). When the DFT-SM scheme alone is used, the data streams are either mapped onto different angles of departures in the case of aligned linear arrays, or mapped onto different orbital angular momentums in the case of aligned circular arrays. Maximum ratio transmission pre-equalizes the channel......By using large point-to-point multiple input multiple output (MIMO), spatial multiplexing of a large number of data streams in wireless communications using millimeter-waves (mm-waves) can be achieved. However, according to the antenna spacing and transmitter-receiver distance, the MIMO channel...... is likely to be ill-conditioned. In such conditions, highly complex schemes such as the singular value decomposition (SVD) are necessary. In this paper, we propose a new low complexity system called discrete Fourier transform based spatial multiplexing (DFT-SM) with maximum ratio transmission (DFT...

  3. Inverter communications using output signal

    Science.gov (United States)

    Chapman, Patrick L.

    2017-02-07

    Technologies for communicating information from an inverter configured for the conversion of direct current (DC) power generated from an alternative source to alternating current (AC) power are disclosed. The technologies include determining information to be transmitted from the inverter over a power line cable connected to the inverter and controlling the operation of an output converter of the inverter as a function of the information to be transmitted to cause the output converter to generate an output waveform having the information modulated thereon.

  4. Integration of TMVA Output into Jupyter notebooks

    CERN Document Server

    Saliji, Albulena

    2016-01-01

    The purpose of this report is to describe the work that I have been doing during these past eight weeks as a Summer Student at CERN. The task which was assigned to me had to do with the integration of TMVA Output into Jupyter notebooks. In order to integrate the TMVA Output into the Jupyter notebook, first, improvement of the TMVA Output in the terminal was required. Once the output was improved, it needed to be transformed into HTML output and at the end it would be possible to integrate that output into the Jupyter notebook.

  5. Correlation between maximum isometric strength variables and specific performance of Brazilian military judokas

    Directory of Open Access Journals (Sweden)

    Michel Moraes Gonçalves

    2017-06-01

    Full Text Available It was our objective to correlate specific performance in the Special Judo Fitness Test (SJFT and the maximum isometric handgrip (HGSMax, scapular traction (STSMax and lumbar traction (LTSMax strength tests in military judo athletes. Twenty-two military athletes from the judo team of the Brazilian Navy Almirante Alexandrino Instruction Centre, with average age of 26.14 ± 3.31 years old, and average body mass of 83.23 ± 14.14 kg participated in the study. Electronic dynamometry tests for HGSMax, STSMax and LTSMax were conducted. Then, after approximately 1 hour-interval, the SJFT protocol was applied. All variables were adjusted to the body mass of the athletes. Pearson correlation coefficient for statistical analysis was used. The results showed moderate negative correlation between the SJFT index and STSMax (r= -0.550, p= 0.008, strong negative correlations between the SJFT index and HGSMax (r= -0.706, p< 0.001, SJFT index and LTSMax (r= -0.721; p= 0.001, besides the correlation between the sum of the three maximum isometric strength tests and the SJFT index (r= -0.786, p< 0.001. This study concludes that negative correlations occur between the SJFT index and maximum isometric handgrip, shoulder and lumbar traction strength and the sum of the three maximum isometric strength tests in military judokas.

  6. Spectroscopic output of {sup 125}I and {sup 103}Pd low dose rate brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Usher-Moga, Jacqueline; Beach, Stephen M.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin--Madison, Madison, Wisconsin 53705 (United States); Global Physics Solutions, St. Joseph, Michigan 49085 (United States); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2009-01-15

    The spectroscopic output of low dose rate (LDR) brachytherapy sources is dependent on the physical design and construction of the source. Characterization of the emitted photons from 12 {sup 125}I and 3 {sup 103}Pd LDR brachytherapy source models is presented. Photon spectra, both along the transverse bisector and at several polar angles, were measured in air with a high-purity reverse electrode germanium (REGe) detector. Measured spectra were corrected to in vacuo conditions via Monte Carlo and analytical methods. The tabulated and plotted spectroscopic data provide a more complete understanding of each source model's output characteristics than can be obtained with other measurement techniques. The variation in fluorescence yield of the {sup 125}I sources containing silver caused greater differences in the emitted spectra and average energies among these seed models than was observed for the {sup 103}Pd sources or the {sup 125}I sources that do not contain silver. Angular spectroscopic data further highlighted the effects of source construction unique to each model, as well as the asymmetric output of many seeds. These data demonstrate the need for the incorporation of such physically measured output characteristics in the Monte Carlo modeling process.

  7. Dependence of US hurricane economic loss on maximum wind speed and storm size

    International Nuclear Information System (INIS)

    Zhai, Alice R; Jiang, Jonathan H

    2014-01-01

    Many empirical hurricane economic loss models consider only wind speed and neglect storm size. These models may be inadequate in accurately predicting the losses of super-sized storms, such as Hurricane Sandy in 2012. In this study, we examined the dependences of normalized US hurricane loss on both wind speed and storm size for 73 tropical cyclones that made landfall in the US from 1988 through 2012. A multi-variate least squares regression is used to construct a hurricane loss model using both wind speed and size as predictors. Using maximum wind speed and size together captures more variance of losses than using wind speed or size alone. It is found that normalized hurricane loss (L) approximately follows a power law relation with maximum wind speed (V max ) and size (R), L = 10 c V max a R b , with c determining an overall scaling factor and the exponents a and b generally ranging between 4–12 and 2–4 respectively. Both a and b tend to increase with stronger wind speed. Hurricane Sandy’s size was about three times of the average size of all hurricanes analyzed. Based on the bi-variate regression model that explains the most variance for hurricanes, Hurricane Sandy’s loss would be approximately 20 times smaller if its size were of the average size with maximum wind speed unchanged. It is important to revise conventional empirical hurricane loss models that are only dependent on maximum wind speed to include both maximum wind speed and size as predictors. (letters)

  8. World Input-Output Network.

    Directory of Open Access Journals (Sweden)

    Federica Cerina

    Full Text Available Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD is one of the first efforts to construct the global multi-regional input-output (GMRIO tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries.

  9. A Study on Porosity Distribution in Nanoporous TiO2 Photoelectrodes for Output Performance of Dye-Sensitized Solar Cells

    International Nuclear Information System (INIS)

    Wei-Wei, Xu; Xiang-Dong, Luo; Wei-Ping, Jing; Lin-Hua, Hu; Song-Yuan, Dai; Chang-Neng, Zhang

    2010-01-01

    Porosity as one of the crucial factors to film morphology affects the overall electrical current-voltage characteristics of dye-sensitized solar cell (DSC). We search for the short-circuit current density, the open-circuit voltage and the maximum power output as the main functional parameters of DSC closely related to porosity under different film thickness. The theoretical analyses show some exciting results. As porosity changes from 0.41 to 0.75, the short-circuit current density shows the optimal value when the film thickness is 8–10 μm. The open-circuit voltage presents different variation tendencies for the film thicknesses within 1–8 μm and within 10–30 μm. The porosity is near 0.41 and the film thickness is about 10 μm, DSC will have the maximum power output. The theoretical studies also illustrate that given a good porosity distribution, DSC can obtain an excellent short-circuit current characteristic, which agrees well with the experimental results reported in previous literature. (cross-disciplinary physics and related areas of science and technology)

  10. Control Strategies for Smoothing of Output Power of Wind Energy Conversion Systems

    Science.gov (United States)

    Pratap, Alok; Urasaki, Naomitsu; Senju, Tomonobu

    2013-10-01

    This article presents a control method for output power smoothing of a wind energy conversion system (WECS) with a permanent magnet synchronous generator (PMSG) using the inertia of wind turbine and the pitch control. The WECS used in this article adopts an AC-DC-AC converter system. The generator-side converter controls the torque of the PMSG, while the grid-side inverter controls the DC-link and grid voltages. For the generator-side converter, the torque command is determined by using the fuzzy logic. The inputs of the fuzzy logic are the operating point of the rotational speed of the PMSG and the difference between the wind turbine torque and the generator torque. By means of the proposed method, the generator torque is smoothed, and the kinetic energy stored by the inertia of the wind turbine can be utilized to smooth the output power fluctuations of the PMSG. In addition, the wind turbines shaft stress is mitigated compared to a conventional maximum power point tracking control. Effectiveness of the proposed method is verified by the numerical simulations.

  11. Smoothing Control of Wind Farm Output by Using Kinetic Energy of Variable Speed Wind Power Generators

    Science.gov (United States)

    Sato, Daiki; Saitoh, Hiroumi

    This paper proposes a new control method for reducing fluctuation of power system frequency through smoothing active power output of wind farm. The proposal is based on the modulation of rotaional kinetic energy of variable speed wind power generators through power converters between permanent magnet synchronous generators (PMSG) and transmission lines. In this paper, the proposed control is called Fluctuation Absorption by Flywheel Characteristics control (FAFC). The FAFC can be easily implemented by adding wind farm output signal to Maximum Power Point Tracking control signal through a feedback control loop. In order to verify the effectiveness of the FAFC control, a simulation study was carried out. In the study, it was assumed that the wind farm consisting of PMSG type wind power generator and induction machine type wind power generaotors is connected with a power sysem. The results of the study show that the FAFC control is a useful method for reducing the impacts of wind farm output fluctuation on system frequency without additional devices such as secondary battery.

  12. ANALISIS CURAH HUJAN DAN DEBIT MODEL SWAT DENGAN METODE MOVING AVERAGE DI DAS CILIWUNG HULU

    Directory of Open Access Journals (Sweden)

    Defri Satiya Zuma

    2017-09-01

    Full Text Available Watershed can be regarded as a hydrological system that has a function in transforming rainwater as an input into outputs such as flow and sediment. The transformation of inputs into outputs has specific forms and properties. The transformation involves many processes, including processes occurred on the surface of the land, river basins, in soil and aquifer. This study aimed to apply the SWAT model  in  Ciliwung Hulu Watershed, asses the effect of average rainfall  on 3 days, 5 days, 7 days and 10 days of the hydrological characteristics in Ciliwung Hulu Watershed. The correlation coefficient (r between rainfall and discharge was positive, it indicated that there was an unidirectional relationship between rainfall and discharge in the upstream, midstream and downstream of the watershed. The upper limit ratio of discharge had a downward trend from upstream to downstream, while the lower limit ratio of  discharge had an upward trend from upstream to downstream. It showed that the discharge peak in Ciliwung  Hulu Watershed from upstream to downstream had a downward trend while the baseflow from upstream to downstream had an upward trend. It showed that the upstream of Ciliwung Hulu Watershed had the highest ratio of discharge peak  and baseflow so it needs the soil and water conservations and technical civil measures. The discussion concluded that the SWAT model could be well applied in Ciliwung Hulu Watershed, the most affecting average rainfall on the hydrological characteristics was the average rainfall of 10 days. On average  rainfall of 10 days, all components had contributed maximally for river discharge.

  13. Compact Source of Electron Beam with Energy of 200 kEv and Average Power of 2 kW

    CERN Document Server

    Kazarezov, Ivan; Balakin, Vladimir E; Bryazgin, Alex; Bulatov, Alexandre; Glazkov, Ivan; Kokin, Evgeny; Krainov, Gennady; Kuznetsov, Gennady I; Molokoedov, Andrey; Tuvik, Alfred

    2005-01-01

    The paper describes a compact electron beam source with average electron energy of 200 keV. The source operates with pulse power up to 2 MW under average power not higher than 2 kW, pulsed beam current up to 10 A, pulse duration up to 2 mks, and repetition rate up to 5 kHz. The electron beam is extracted through aluminium-beryllium alloy foil. The pulse duration and repetition rate can be changed from control desk. High-voltage generator for the source with output voltage up to 220 kV is realized using the voltage-doubling circuit which consists of 30 sections. The insulation type - gas, SF6 under pressure of 8 atm. The cooling of the foil supporting tubes is provided by a water-alcohol mixture from an independent source. The beam output window dimensions are 180?75 mm, the energy spread in the beam +10/-30%, the source weight is 80 kg.

  14. Elastic Cube Actuator with Six Degrees of Freedom Output

    Directory of Open Access Journals (Sweden)

    Pengchuan Wang

    2015-09-01

    Full Text Available Unlike conventional rigid actuators, soft robotic technologies possess inherent compliance, so they can stretch and twist along every axis without the need for articulated joints. This compliance is exploited here using dielectric elastomer membranes to develop a novel six degrees of freedom (6-DOF polymer actuator that unifies ordinarily separate components into a simple cubic structure. This cube actuator design incorporates elastic dielectric elastomer membranes on four faces which are coupled by a cross-shaped end effector. The inherent elasticity of each membrane greatly reduces kinematic constraint and enables a 6-DOF actuation output to be produced via the end effector. An electro-mechanical model of the cube actuator is presented that captures the non-linear hyperelastic behaviour of the active membranes. It is demonstrated that the model accurately predicts actuator displacement and blocking moment for a range of input voltages. Experimental testing of a prototype 60 mm device demonstrates 6-DOF operation. The prototype produces maximum linear and rotational displacements of ±2.6 mm (±4.3% and ±4.8° respectively and a maximum blocking moment of ±76 mNm. The capacity for full 6-DOF actuation from a compact, readily scalable and easily fabricated polymeric package enables implementation in a range of mechatronics and robotics applications.

  15. New solid laser: Ceramic laser. From ultra stable laser to ultra high output laser

    International Nuclear Information System (INIS)

    Ueda, Kenichi

    2006-01-01

    An epoch-making solid laser is developed. It is ceramic laser, polycrystal, which is produced as same as glass and shows ultra high output. Ti 3+ :Al 2 O 3 laser crystal and the CPA (chirped pulse amplification) technique realized new ultra high output lasers. Japan has developed various kinds of ceramic lasers, from 10 -2 to 67 x 10 3 w average output, since 1995. These ceramic lasers were studied by gravitational radiation astronomy. The scattering coefficient of ceramic laser is smaller than single crystals. The new fast ignition method is proposed by Institute of Laser Engineering of Osaka University, Japan. Ultra-intense short pulse laser can inject the required energy to the high-density imploded core plasma within the core disassembling time. Ti 3+ :Al 2 O 3 crystal for laser, ceramic YAG of large caliber for 100 kW, transparent laser ceramic from nano-crystals, crystal grain and boundary layer between grains, the scattering coefficient of single crystal and ceramic, and the derived release cross section of Yb:YAG ceramic are described. (S.Y.)

  16. Methodological concerns for determining power output in the jump squat.

    Science.gov (United States)

    Cormie, Prue; Deane, Russell; McBride, Jeffrey M

    2007-05-01

    The purpose of this study was to investigate the validity of power measurement techniques during the jump squat (JS) utilizing various combinations of a force plate and linear position transducer (LPT) devices. Nine men with at least 6 months of prior resistance training experience participated in this acute investigation. One repetition maximums (1RM) in the squat were determined, followed by JS testing under 2 loading conditions (30% of 1RM [JS30] and 90% of 1RM [JS90]). Three different techniques were used simultaneously in data collection: (a) 1 linear position transducer (1-LPT); (b) 1 linear position transducer and a force plate (1-LPT + FP); and (c) 2 linear position transducers and a force place (2-LPT + FP). Vertical velocity-, force-, and power-time curves were calculated for each lift using these methodologies and were compared. Peak force and peak power were overestimated by 1-LPT in both JS30 and JS90 compared with 2-LPT + FP and 1-LPT + FP (p squat varies according to the measurement technique utilized. The 1-LPT methodology is not a valid means of determining power output in the jump squat. Furthermore, the 1-LPT + FP method may not accurately represent power output in free weight movements that involve a significant amount of horizontal motion.

  17. Multi-decadal Variability of the Wind Power Output

    Science.gov (United States)

    Kirchner Bossi, Nicolas; García-Herrera, Ricardo; Prieto, Luis; Trigo, Ricardo M.

    2014-05-01

    The knowledge of the long-term wind power variability is essential to provide a realistic outlook on the power output during the lifetime of a planned wind power project. In this work, the Power Output (Po) of a market wind turbine is simulated with a daily resolution for the period 1871-2009 at two different locations in Spain, one at the Central Iberian Plateau and another at the Gibraltar Strait Area. This is attained through a statistical downscaling of the daily wind conditions. It implements a Greedy Algorithm as classificator of a geostrophic-based wind predictor, which is derived by considering the SLP daily field from the 56 ensemble members of the longest homogeneous reanalysis available (20CR, 1871-2009). For calibration and validation purposes we use 10 years of wind observations (the predictand) at both sites. As a result, a series of 139 annual wind speed Probability Density Functions (PDF) are obtained, with a good performance in terms of wind speed uncertainty reduction (average daily wind speed MAE=1.48 m/s). The obtained centennial series allow to investigate the multi-decadal variability of wind power from different points of view. Significant periodicities around the 25-yr frequency band, as well as long-term linear trends are detected at both locations. In addition, a negative correlation is found between annual Po at both locations, evidencing the differences in the dynamical mechanisms ruling them (and possible complementary behavior). Furthermore, the impact that the three leading large-scale circulation patterns over Iberia (NAO, EA and SCAND) exert over wind power output is evaluated. Results show distinct (and non-stationary) couplings to these forcings depending on the geographical position and season or month. Moreover, significant non-stationary correlations are observed with the slow varying Atlantic Multidecadal Oscillation (AMO) index for both case studies. Finally, an empirical relationship is explored between the annual Po and the

  18. An automotive thermoelectric-photovoltaic hybrid energy system using maximum power point tracking

    International Nuclear Information System (INIS)

    Zhang Xiaodong; Chau, K.T.

    2011-01-01

    In recent years, there has been active research on exhaust gas waste heat energy recovery for automobiles. Meanwhile, the use of solar energy is also proposed to promote on-board renewable energy and hence to improve their fuel economy. In this paper, a new thermoelectric-photovoltaic (TE-PV) hybrid energy system is proposed and implemented for automobiles. The key is to newly develop the power conditioning circuit using maximum power point tracking so that the output power of the proposed TE-PV hybrid energy system can be maximized. An experimental system is prototyped and tested to verify the validity of the proposed system.

  19. Robust optimization of the output voltage of nanogenerators by statistical design of experiments

    KAUST Repository

    Song, Jinhui

    2010-09-01

    Nanogenerators were first demonstrated by deflecting aligned ZnO nanowires using a conductive atomic force microscopy (AFM) tip. The output of a nanogenerator is affected by three parameters: tip normal force, tip scanning speed, and tip abrasion. In this work, systematic experimental studies have been carried out to examine the combined effects of these three parameters on the output, using statistical design of experiments. A statistical model has been built to analyze the data and predict the optimal parameter settings. For an AFM tip of cone angle 70° coated with Pt, and ZnO nanowires with a diameter of 50 nm and lengths of 600 nm to 1 μm, the optimized parameters for the nanogenerator were found to be a normal force of 137 nN and scanning speed of 40 μm/s, rather than the conventional settings of 120 nN for the normal force and 30 μm/s for the scanning speed. A nanogenerator with the optimized settings has three times the average output voltage of one with the conventional settings. © 2010 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

  20. Robust optimization of the output voltage of nanogenerators by statistical design of experiments

    KAUST Repository

    Song, Jinhui; Xie, Huizhi; Wu, Wenzhuo; Roshan Joseph, V.; Jeff Wu, C. F.; Wang, Zhong Lin

    2010-01-01

    Nanogenerators were first demonstrated by deflecting aligned ZnO nanowires using a conductive atomic force microscopy (AFM) tip. The output of a nanogenerator is affected by three parameters: tip normal force, tip scanning speed, and tip abrasion. In this work, systematic experimental studies have been carried out to examine the combined effects of these three parameters on the output, using statistical design of experiments. A statistical model has been built to analyze the data and predict the optimal parameter settings. For an AFM tip of cone angle 70° coated with Pt, and ZnO nanowires with a diameter of 50 nm and lengths of 600 nm to 1 μm, the optimized parameters for the nanogenerator were found to be a normal force of 137 nN and scanning speed of 40 μm/s, rather than the conventional settings of 120 nN for the normal force and 30 μm/s for the scanning speed. A nanogenerator with the optimized settings has three times the average output voltage of one with the conventional settings. © 2010 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

  1. Output Power Smoothing Control for a Wind Farm Based on the Allocation of Wind Turbines

    Directory of Open Access Journals (Sweden)

    Ying Zhu

    2018-06-01

    Full Text Available This paper presents a new output power smoothing control strategy for a wind farm based on the allocation of wind turbines. The wind turbines in the wind farm are divided into control wind turbines (CWT and power wind turbines (PWT, separately. The PWTs are expected to output as much power as possible and a maximum power point tracking (MPPT control strategy combining the rotor inertia based power smoothing method is adopted. The CWTs are in charge of the output power smoothing for the whole wind farm by giving the calculated appropriate power. The battery energy storage system (BESS with small capacity is installed to be the support and its charge and discharge times are greatly reduced comparing with the traditional ESSs based power smoothing strategies. The simulation model of the permanent magnet synchronous generators (PMSG based wind farm by considering the wake effect is built in Matlab/Simulink to test the proposed power smoothing method. Three different working modes of the wind farm are given in the simulation and the simulation results verify the effectiveness of the proposed power smoothing control strategy.

  2. Simulation model of ANN based maximum power point tracking controller for solar PV system

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Anil K.; Singh, Bhupal [Department of Electrical and Electronics Engineering, Ajay Kumar Garg Engineering College, Ghaziabad 201009 (India); Kaushika, N.D.; Agarwal, Niti [School of Research and Development, Bharati Vidyapeeth College of Engineering, A-4 Paschim Vihar, New Delhi 110063 (India)

    2011-02-15

    In this paper the simulation model of an artificial neural network (ANN) based maximum power point tracking controller has been developed. The controller consists of an ANN tracker and the optimal control unit. The ANN tracker estimates the voltages and currents corresponding to a maximum power delivered by solar PV (photovoltaic) array for variable cell temperature and solar radiation. The cell temperature is considered as a function of ambient air temperature, wind speed and solar radiation. The tracker is trained employing a set of 124 patterns using the back propagation algorithm. The mean square error of tracker output and target values is set to be of the order of 10{sup -5} and the successful convergent of learning process takes 1281 epochs. The accuracy of the ANN tracker has been validated by employing different test data sets. The control unit uses the estimates of the ANN tracker to adjust the duty cycle of the chopper to optimum value needed for maximum power transfer to the specified load. (author)

  3. An investigation of accelerator head scatter and output factor in air

    International Nuclear Information System (INIS)

    Ding, George X.

    2004-01-01

    Our purpose in this study was to investigate whether the Monte Carlo simulation can accurately predict output factors in air. Secondary goals were to study the head scatter components and investigate the collimator exchange effect. The Monte Carlo code, BEAMnrc, was used in the study. Photon beams of 6 and 18 MV were from a Varian Clinac 2100EX accelerator and the measurements were performed using an ionization chamber in a mini-phantom. The Monte Carlo calculated in air output factors was within 1% of measured values. The simulation provided information of the origin and the magnitude of the collimator exchange effect. It was shown that the collimator backscatter to the beam monitor chamber played a significant role in the beam output factors. However the magnitude of the scattered dose contributions from the collimator at the isocenter is negligible. The maximum scattered dose contribution from the collimators was about 0.15% and 0.4% of the total dose at the isocenter for a 6 and 18 MV beam, respectively. The scattered dose contributions from the flattening filter at the isocenter were about 0.9-3% and 0.2-6% of the total dose for field sizes of 4x4 cm 2 -40x40 cm 2 for the 6 and 18 MV beam, respectively. The study suggests that measurements of head scatter factors be done at large depth well beyond the depth of electron contamination. The insight information may have some implications for developing generalized empirical models to calculate the head scatter

  4. Performance Analysis of a Maximum Power Point Tracking Technique using Silver Mean Method

    Directory of Open Access Journals (Sweden)

    Shobha Rani Depuru

    2018-01-01

    Full Text Available The proposed paper presents a simple and particularly efficacious Maximum Power Point Tracking (MPPT algorithm based on Silver Mean Method (SMM. This method operates by choosing a search interval from the P-V characteristics of the given solar array and converges to MPP of the Solar Photo-Voltaic (SPV system by shrinking its interval. After achieving the maximum power, the algorithm stops shrinking and maintains constant voltage until the next interval is decided. The tracking capability efficiency and performance analysis of the proposed algorithm are validated by the simulation and experimental results with a 100W solar panel for variable temperature and irradiance conditions. The results obtained confirm that even without any perturbation and observation process, the proposed method still outperforms the traditional perturb and observe (P&O method by demonstrating far better steady state output, more accuracy and higher efficiency.

  5. MAXIMUM CORONAL MASS EJECTION SPEED AS AN INDICATOR OF SOLAR AND GEOMAGNETIC ACTIVITIES

    International Nuclear Information System (INIS)

    Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Gopalswamy, N.; Ozguc, A.; Rozelot, J. P.

    2011-01-01

    We investigate the relationship between the monthly averaged maximal speeds of coronal mass ejections (CMEs), international sunspot number (ISSN), and the geomagnetic Dst and Ap indices covering the 1996-2008 time interval (solar cycle 23). Our new findings are as follows. (1) There is a noteworthy relationship between monthly averaged maximum CME speeds and sunspot numbers, Ap and Dst indices. Various peculiarities in the monthly Dst index are correlated better with the fine structures in the CME speed profile than that in the ISSN data. (2) Unlike the sunspot numbers, the CME speed index does not exhibit a double peak maximum. Instead, the CME speed profile peaks during the declining phase of solar cycle 23. Similar to the Ap index, both CME speed and the Dst indices lag behind the sunspot numbers by several months. (3) The CME number shows a double peak similar to that seen in the sunspot numbers. The CME occurrence rate remained very high even near the minimum of the solar cycle 23, when both the sunspot number and the CME average maximum speed were reaching their minimum values. (4) A well-defined peak of the Ap index between 2002 May and 2004 August was co-temporal with the excess of the mid-latitude coronal holes during solar cycle 23. The above findings suggest that the CME speed index may be a useful indicator of both solar and geomagnetic activities. It may have advantages over the sunspot numbers, because it better reflects the intensity of Earth-directed solar eruptions.

  6. Accessing National Water Model Output for Research and Application: An R package

    Science.gov (United States)

    Johnson, M.; Coll, J.

    2017-12-01

    With the National Water Model becoming operational in August of 2016, the need for a open source way to translate a huge amount of data into actionable intelligence and innovative research is apparent. The first step in doing this is to provide a package for accessing, managing, and writing data in a way that is both interpretable, portable, and useful to the end user in both the R environment, and other applications. This can be as simple as subsetting the outputs and writing to a CSV, but can also include converting discharge output to more meaningful statistics and measurements, and methods to visualize data in ways that are meaningful to a wider audience. The NWM R package presented here aims to serve this need through a suite of functions fit for researchers, first responders, and average citizens. A vignette of how this package can be applied to real-time flood mapping will be demonstrated.

  7. Jarzynski equality in the context of maximum path entropy

    Science.gov (United States)

    González, Diego; Davis, Sergio

    2017-06-01

    In the global framework of finding an axiomatic derivation of nonequilibrium Statistical Mechanics from fundamental principles, such as the maximum path entropy - also known as Maximum Caliber principle -, this work proposes an alternative derivation of the well-known Jarzynski equality, a nonequilibrium identity of great importance today due to its applications to irreversible processes: biological systems (protein folding), mechanical systems, among others. This equality relates the free energy differences between two equilibrium thermodynamic states with the work performed when going between those states, through an average over a path ensemble. In this work the analysis of Jarzynski's equality will be performed using the formalism of inference over path space. This derivation highlights the wide generality of Jarzynski's original result, which could even be used in non-thermodynamical settings such as social systems, financial and ecological systems.

  8. Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

    Science.gov (United States)

    Othman, Ahmed M.; El-arini, Mahdi M. M.; Ghitas, Ahmed; Fathy, Ahmed

    2012-12-01

    In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV) systems. Maximum power point tracking (MPPT) plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT) using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O) algorithm and is compared to a designed fuzzy logic controller (FLC). The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

  9. Improved performance of high average power semiconductor arrays for applications in diode pumped solid state lasers

    International Nuclear Information System (INIS)

    Beach, R.; Emanuel, M.; Benett, W.; Freitas, B.; Ciarlo, D.; Carlson, N.; Sutton, S.; Skidmore, J.; Solarz, R.

    1994-01-01

    The average power performance capability of semiconductor diode laser arrays has improved dramatically over the past several years. These performance improvements, combined with cost reductions pursued by LLNL and others in the fabrication and packaging of diode lasers, have continued to reduce the price per average watt of laser diode radiation. Presently, we are at the point where the manufacturers of commercial high average power solid state laser systems used in material processing applications can now seriously consider the replacement of their flashlamp pumps with laser diode pump sources. Additionally, a low cost technique developed and demonstrated at LLNL for optically conditioning the output radiation of diode laser arrays has enabled a new and scalable average power diode-end-pumping architecture that can be simply implemented in diode pumped solid state laser systems (DPSSL's). This development allows the high average power DPSSL designer to look beyond the Nd ion for the first time. Along with high average power DPSSL's which are appropriate for material processing applications, low and intermediate average power DPSSL's are now realizable at low enough costs to be attractive for use in many medical, electronic, and lithographic applications

  10. Direct torque and flux regulation of synchronous reluctance motor drives based on input-output feedback linearization

    International Nuclear Information System (INIS)

    Abootorabi Zarchi, H.; Arab Markadeh, Gh.R.; Soltani, J.

    2010-01-01

    In this paper, a nonlinear speed tracking controller is introduced for three-phase synchronous reluctance motor (SynRM) on the basis of input-output feedback linearization (IOFL), considering the different control strategies (maximum torque per Ampere, high efficiency and minimum KVA rating for the inverter) related to this motor. The proposed control approach is capable of decoupling control of stator flux and motor generated torque. The validity and effectiveness of the method is verified by simulation and experimental results.

  11. Preliminary design of the BPM electronics memory scanner/dual boxcar averager for the Advanced Photon Source

    International Nuclear Information System (INIS)

    Votaw, A.J.

    1992-01-01

    The memory scanner/dual boxcar averager are VXI modules that are part of the Advanced Photon Source (APS) beam position monitor (BPM) data acquisition system. Each pair of modules is designed to gather and process digital data from up to nine digital channels transmitting the BPM data from the storage ring (360 locations) and the synchrotron (80 locations). They store beam history in a buffer, store the latest scan of all channels, and provide boxcar averaged X and Y position data for the global orbit feedback system, provide boxcar average X and Y position data for beam diagnostics, and a buffered output of SCDU data as it is scanned for the beam abort interlock system. The system's capability to support single pass, closed orbit and tune measurement functions will also be briefly described

  12. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  13. Power output of microbial fuel cell emphasizing interaction of anodic binder with bacteria

    Science.gov (United States)

    Li, Hongying; Liao, Bo; Xiong, Juan; Zhou, Xingwang; Zhi, Huozhen; Liu, Xiang; Li, Xiaoping; Li, Weishan

    2018-03-01

    Electrochemically active biofilm is necessary for the electron transfer between bacteria and anodic electrode in microbial fuel cells and selecting the type of anodic electrode material that favours formation of electrochemically active biofilm is crucial for the microbial fuel cell operation. We report a new finding that the interaction of anodic binder with bacteria plays more important role than its hydrophilicity for forming an electrochemically active biofilm, which is emphasized by applying poly(bisphenol A-co-epichorohydrin) as an anodic binder of the microbial fuel cell based on carbon nanotubes as anodic electrode and Escherichia coli as bacterium. The physical characterizations and electrochemical measurements demonstrate that poly(bisphenol A-co-epichorohydrin) exhibits a strong interaction with bacteria and thus provides the microbial fuel cell with excellent power density output. The MFC using poly(bisphenol A-co-epichorohydrin) reaches a maximum power density output of 3.8 W m-2. This value is larger than that of the MFCs using polytetrafluoroethylene that has poorer hydrophilicity, or polyvinyl alcohol that has better hydrophilicity but exhibits weaker interaction with bacteria than poly(bisphenol A-co-epichorohydrin).

  14. Oil output's changing fortunes

    International Nuclear Information System (INIS)

    Eldridge, D.

    1994-01-01

    The Petroleum Economist, previously the Petroleum Press Service, has been making annual surveys of output levels of petroleum in all the oil-producing countries since its founding in 1934. This article documents trends and changes in the major oil-producing countries output from 1934 until the present. This analysis is linked with the political and historical events accompanying these changes, notably the growth of Middle Eastern oil production, the North Sea finds and most recently, Iraq's invasion of Kuwait in 1990. (UK)

  15. Efficacy of spatial averaging of infrasonic pressure in varying wind speeds

    International Nuclear Information System (INIS)

    DeWolf, Scott; Walker, Kristoffer T.; Zumberge, Mark A.; Denis, Stephane

    2013-01-01

    Wind noise reduction (WNR) is important in the measurement of infra-sound. Spatial averaging theory led to the development of rosette pipe arrays. The efficacy of rosettes decreases with increasing wind speed and only provides a maximum of 20 dB WNR due to a maximum size limitation. An Optical Fiber Infra-sound Sensor (OFIS) reduces wind noise by instantaneously averaging infra-sound along the sensor's length. In this study two experiments quantify the WNR achieved by rosettes and OFISs of various sizes and configurations. Specifically, it is shown that the WNR for a circular OFIS 18 m in diameter is the same as a collocated 32-inlet pipe array of the same diameter. However, linear OFISs ranging in length from 30 to 270 m provide a WNR of up to 30 dB in winds up to 5 m/s. The measured WNR is a logarithmic function of the OFIS length and depends on the orientation of the OFIS with respect to wind direction. OFISs oriented parallel to the wind direction achieve 4 dB greater WNR than those oriented perpendicular to the wind. Analytical models for the rosette and OFIS are developed that predict the general observed relationships between wind noise reduction, frequency, and wind speed. (authors)

  16. SU-E-J-208: Feasibility Study On Using Small Plastic Phantoms for Auditing Radiation Output of MR-Linac Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Z; Alvarez, P; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To study feasibility of using small plastic phantoms designed for conventional linac output auditing to measure the output of MR-Linac systems. Methods: For simulations, the CT scan of an IROC(formerly RPC) acrylic block phantom designed for 8 MV beams was imported in a research version of the treatment planning system (Monaco). Dose delivered to three TLDs in the block was calculated with a Monte Carlo algorithm and a beam model based on an MR-linac prototype with and without a magnetic field (B=1.5T). In a large mathematical water phantom, the same beam was used to calculate dose in full scatter conditions. The block factor (F) was calculated as the ratio of the average dose to the block TLDs to the dose at the reference point in the mathematical phantom. For experimental measurement, four IROC blocks were irradiated with the MR-linac prototype, and data were analyzed by IROC. Results: The F factor without a B field was 1.053. When a B field was applied, it changed the dose distribution in the block, especially on the edges. With a B field parallel to the long axes of the TLD, F was 1.038. However, with a perpendicular B field, F factor increased slightly to 1.075. In the IROC report, the output determined with two blocks parallel to the B field was 2.3% higher than the output by the two blocks perpendicular to the B field. The average of all four blocks was within 2% of machine output measured with an ion chamber. Conclusion: It may be feasible to expand the utility of the acrylic block phantoms for radiation output auditing from conventional linacs to MR-linacs. However, the scatter correction factor can change due to the B field and its orientation to the block. More symmetric phantom designs may be less prone to mistakes. We acknowledge research support from Elekta.

  17. DIST/AVC Out-Put Definition.

    Science.gov (United States)

    Wilkinson, Gene L.

    The first stage of development of a management information system for DIST/AVC (Division of Instructional Technology/Audio-Visual Center) is the definition of out-put units. Some constraints on the definition of output units are: 1) they should reflect goals of the organization, 2) they should reflect organizational structure and procedures, and…

  18. Efficiency of Photovoltaic Maximum Power Point Tracking Controller Based on a Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Ammar Al-Gizi

    2017-07-01

    Full Text Available This paper examines the efficiency of a fuzzy logic control (FLC based maximum power point tracking (MPPT of a photovoltaic (PV system under variable climate conditions and connected load requirements. The PV system including a PV module BP SX150S, buck-boost DC-DC converter, MPPT, and a resistive load is modeled and simulated using Matlab/Simulink package. In order to compare the performance of FLC-based MPPT controller with the conventional perturb and observe (P&O method at different irradiation (G, temperature (T and connected load (RL variations – rising time (tr, recovering time, total average power and MPPT efficiency topics are calculated. The simulation results show that the FLC-based MPPT method can quickly track the maximum power point (MPP of the PV module at the transient state and effectively eliminates the power oscillation around the MPP of the PV module at steady state, hence more average power can be extracted, in comparison with the conventional P&O method.

  19. On application of a new hybrid maximum power point tracking (MPPT) based photovoltaic system to the closed plant factory

    International Nuclear Information System (INIS)

    Jiang, Joe-Air; Su, Yu-Li; Shieh, Jyh-Cherng; Kuo, Kun-Chang; Lin, Tzu-Shiang; Lin, Ta-Te; Fang, Wei; Chou, Jui-Jen; Wang, Jen-Cheng

    2014-01-01

    Highlights: • Hybrid MPPT method was developed and utilized in a PV system of closed plant factory. • The tracking of the maximum power output of PV system can be achieved in real time. • Hybrid MPPT method not only decreases energy loss but increases power utilization. • The feasibility of applying PV system to the closed plant factory has been examined. • The PV system significantly reduced CO 2 emissions and curtailed the fossil fuels. - Abstract: Photovoltaic (PV) generation systems have been shown to have a promising role for use in high electric-load buildings, such as the closed plant factory which is dependent upon artificial lighting. The power generated by the PV systems can be either directly supplied to the buildings or fed back into the electrical grid to reduce the high economic costs and environmental impact associated with the traditional energy sources such as nuclear power and fossil fuels. However, PV systems usually suffer from low energy-conversion efficiency, and it is therefore necessary to improve their performance by tackling the energy loss issues. The maximum power point tracking (MPPT) control technique is essential to the PV-assisted generation systems in order to achieve the maximum power output in real time. In this study, we integrate the previously proposed direct-prediction MPP method with a perturbation and observation (P and O) method to develop a new hybrid MPPT method. The proposed MPPT method is further utilized in the PV inverters in a PV system installed on the roof of a closed plant factory at National Taiwan University. The tested PV system is constructed as a two-stage grid-connected photovoltaic power conditioning (PVPC) system with a boost-buck full bridge design configuration. A control scheme based on the hybrid MPPT method is also developed and implemented in the PV inverters of the PVPC system to achieve tracking of the maximum power output of the PV system in real time. Based on experimental results

  20. Theoretical analysis of magnetic sensor output voltage

    International Nuclear Information System (INIS)

    Liu Haishun; Dun Chaochao; Dou Linming; Yang Weiming

    2011-01-01

    The output voltage is an important parameter to determine the stress state in magnetic stress measurement, the relationship between the output voltage and the difference in the principal stresses was investigated by a comprehensive application of magnetic circuit theory, magnetization theory, stress analysis as well as the law of electromagnetic induction, and a corresponding quantitative equation was derived. It is drawn that the output voltage is proportional to the difference in the principal stresses, and related to the angle between the principal stress and the direction of the sensor. This investigation provides a theoretical basis for the principle stresses measurement by output voltage. - Research highlights: → A comprehensive investigation of magnetic stress signal. → Derived a quantitative equation about output voltage and the principal stresses. → The output voltage is proportional to the difference of the principal stresses. → Provide a theoretical basis for the principle stresses measurement.

  1. Output Error Analysis of Planar 2-DOF Five-bar Mechanism

    Science.gov (United States)

    Niu, Kejia; Wang, Jun; Ting, Kwun-Lon; Tao, Fen; Cheng, Qunchao; Wang, Quan; Zhang, Kaiyang

    2018-03-01

    Aiming at the mechanism error caused by clearance of planar 2-DOF Five-bar motion pair, the method of equivalent joint clearance of kinematic pair to virtual link is applied. The structural error model of revolute joint clearance is established based on the N-bar rotation laws and the concept of joint rotation space, The influence of the clearance of the moving pair is studied on the output error of the mechanis. and the calculation method and basis of the maximum error are given. The error rotation space of the mechanism under the influence of joint clearance is obtained. The results show that this method can accurately calculate the joint space error rotation space, which provides a new way to analyze the planar parallel mechanism error caused by joint space.

  2. Long-term WWER-440 dynamics in cyclic power output changes

    International Nuclear Information System (INIS)

    Petruzela, I.

    1989-01-01

    Xenon poisoning is one of the main factors limiting the operation of a nuclear power plant with a WWER-440 reactor in the variable load mode, when long-term dynamics applies to cyclic power output changes. An analysis of the xenon poisoning linearized transfer shows that a phase shift of 180deg takes place between the summed-up reactivity change due to a power change and the reactivity change due to xenon poisoning, this for a sine-wave power change with a period of 24 hours. Thus, the requirements are minimized for the change in reactivity of the control elements, and the maximum value can be achieved of released reactivity that can be utilized before the end of the campaign. (B.S.). 6 figs., 4 tabs., 9 refs

  3. Enhancement of anodic biofilm formation and current output in microbial fuel cells by composite modification of stainless steel electrodes

    Science.gov (United States)

    Liang, Yuxiang; Feng, Huajun; Shen, Dongsheng; Li, Na; Guo, Kun; Zhou, Yuyang; Xu, Jing; Chen, Wei; Jia, Yufeng; Huang, Bin

    2017-02-01

    In this paper, we first systematically investigate the current output performance of stainless steel electrodes (SS) modified by carbon coating (CC), polyaniline coating (PANI), neutral red grafting (NR), surface hydrophilization (SDBS), and heat treatment (HEAT). The maximum current density of 13.0 A m-2 is obtained on CC electrode (3.0 A m-2 of the untreated anode). Such high performance should be attributed to its large effective surface area, which is 2.3 times that of the unmodified electrode. Compared with SS electrode, about 3-fold increase in current output is achieved with PANI. Functionalization with hydrophilic group and electron medium result in the current output rising to 1.5-2 fold, through enhancing bioadhesive and electron transport rate, respectively. CC modification is the best choice of single modification for SS electrode in this study. However, this modification is not perfect because of its poor hydrophilicity. So CC electrode is modified by SDBS for further enhancing the current output to 16 A m-2. These results could provide guidance for the choice of suitable single modification on SS electrodes and a new method for the perfection of electrode performance through composite modification.

  4. Output, renewable energy consumption and trade in Africa

    International Nuclear Information System (INIS)

    Ben Aïssa, Mohamed Safouane; Ben Jebli, Mehdi; Ben Youssef, Slim

    2014-01-01

    We use panel cointegration techniques to examine the relationship between renewable energy consumption, trade and output in a sample of 11 African countries covering the period 1980–2008. The results from panel error correction model reveal that there is evidence of a bidirectional causality between output and exports and between output and imports in both the short and long-run. However, in the short-run, there is no evidence of causality between output and renewable energy consumption and between trade (exports or imports) and renewable energy consumption. Also, in the long-run, there is no causality running from output or trade to renewable energy. In the long-run, our estimations show that renewable energy consumption and trade have a statistically significant and positive impact on output. Our energy policy recommendations are that national authorities should design appropriate fiscal incentives to encourage the use of renewable energies, create more regional economic integration for renewable energy technologies, and encourage trade openness because of its positive impact on technology transfer and on output. - Highlights: • We examine the relationship between renewable energy consumption, trade and output in African countries. • There is a bidirectional causality between output and trade in both the short and long-run. • In the short-run, there is no causality between renewable energy consumption and trade or output. • In the long-run, renewable energy consumption and trade have a statistically significant positive impact on output. • African authorities should encourage trade openness because of its positive impact on technology transfer and on output

  5. Experimental and theoretical analysis of cell module output performance for a thermophotovoltaic system

    International Nuclear Information System (INIS)

    Xu, Xiaojie; Ye, Hong; Xu, Yexin; Shen, Mingrong; Zhang, Xiaojing; Wu, Xi

    2014-01-01

    Highlights: • An accurate theoretical model for thermophotovoltaic system is constructed. • Parallel connected module is superior if radiator temperature is uneven. • Series connected module is superior if cell temperature is uneven. • Short circuit current of series module rises when the shunt resistance decreases. • Fill factor is not always accurate to evaluate the module performance. - Abstract: An experimental thermophotovoltaic (TPV) system with a cylindrical-geometry radiator was established to test the output performances of modules under different conditions. The results demonstrate that the output performance of a cell module decreases when the combustion power increases because of the uneven temperature of the radiator or cells. On this basis, a theoretical model for a TPV system was constructed to compare the performance under different conditions of the series-connected (SC) module and the parallel-connected (PC) module, and was verified by the experimental results. The influences of the temperature gradient of the radiator or the cell module, and the series and shunt resistance of the TPV cell on the module performance were analyzed in detail. The results demonstrate that the PC module can effectively reduce the mismatch loss of output power caused by the uneven radiator temperature. The PC module, for instance, has a maximum output power of 2.54 times higher than that of the SC module when the radiator temperature difference is 500 K. However, the output performance of the module connected in series is superior to the PC module while the cell temperature is non-uniform. The output power of the SC module is 9.93% higher than that of the PC module at the cell temperature difference of 125 K. The short circuit current of the SC module is sensitive to the series and shunt resistance if the radiator temperature distribution is non-uniform. As the shunt resistance falls from ∞ to 0.5 Ω, the current varies from 1.757 A to 4.488 A when the

  6. Maximum-power-point tracking control of solar heating system

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

    The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

  7. Scintillation camera with improved output means

    International Nuclear Information System (INIS)

    Lange, K.; Wiesen, E.J.; Woronowicz, E.M.

    1978-01-01

    In a scintillation camera system, the output pulse signals from an array of photomultiplier tubes are coupled to the inputs of individual preamplifiers. The preamplifier output signals are coupled to circuitry for computing the x and y coordinates of the scintillations. A cathode ray oscilloscope is used to form an image corresponding with the pattern in which radiation is emitted by a body. Means for improving the uniformity and resolution of the scintillations are provided. The means comprise biasing means coupled to the outputs of selected preamplifiers so that output signals below a predetermined amplitude are not suppressed and signals falling within increasing ranges of amplitudes are increasingly suppressed. In effect, the biasing means make the preamplifiers non-linear for selected signal levels

  8. Input-output analysis of high-speed turbulent jet noise

    Science.gov (United States)

    Jeun, Jinah; Nichols, Joseph W.

    2015-11-01

    We apply input-output analysis to predict and understand the aeroacoustics of high-speed isothermal turbulent jets. We consider axisymmetric linear perturbations about Reynolds-averaged Navier-Stokes solutions of ideally expanded turbulent jets with Mach numbers 0 . 6 parabolized stability equations (PSE), and this mode dominates the response. For subsonic jets, however, the singular values indicate that the contributions of suboptimal modes to noise generation are nearly equal to that of the optimal mode, explaining why PSE misses some of the farfield sound in this case. Finally, high-fidelity large eddy simulation (LES) is used to assess the prevalence of suboptimal modes in the unsteady data. By projecting LES data onto the corresponding input modes, the weighted gain of each mode is examined.

  9. Adaptive double-integral-sliding-mode-maximum-power-point tracker for a photovoltaic system

    Directory of Open Access Journals (Sweden)

    Bidyadhar Subudhi

    2015-10-01

    Full Text Available This study proposed an adaptive double-integral-sliding-mode-controller-maximum-power-point tracker (DISMC-MPPT for maximum-power-point (MPP tracking of a photovoltaic (PV system. The objective of this study is to design a DISMC-MPPT with a new adaptive double-integral-sliding surface in order that MPP tracking is achieved with reduced chattering and steady-state error in the output voltage or current. The proposed adaptive DISMC-MPPT possesses a very simple and efficient PWM-based control structure that keeps switching frequency constant. The controller is designed considering the reaching and stability conditions to provide robustness and stability. The performance of the proposed adaptive DISMC-MPPT is verified through both MATLAB/Simulink simulation and experiment using a 0.2 kW prototype PV system. From the obtained results, it is found out that this DISMC-MPPT is found to be more efficient compared with that of Tan's and Jiao's DISMC-MPPTs.

  10. 1018 nm Yb-doped high-power fiber laser pumped by broadband pump sources around 915 nm with output power above 100 W

    DEFF Research Database (Denmark)

    Midilli, Yakup; Efunbajo, Oyewole Benjamin; Şimşek, Bartu

    2017-01-01

    laser were also addressed in this study. Finally, we have tested this system for high power experimentation and obtained 67% maximum optical-to-optical efficiency at an approximately 110 W output power level. To the best of our knowledge, this is the first 1018 nm ytterbium-doped all-fiber laser pumped...

  11. Analysis of Output Levels of an MP3 Player: Effects of Earphone Type, Music Genre, and Listening Duration.

    Science.gov (United States)

    Shim, Hyunyong; Lee, Seungwan; Koo, Miseung; Kim, Jinsook

    2018-02-26

    To prevent noise induced hearing losses caused by listening to music with personal listening devices for young adults, this study was aimed to measure output levels of an MP3 and to identify preferred listening levels (PLLs) depending on earphone types, music genres, and listening durations. Twenty-two normal hearing young adults (mean=18.82, standard deviation=0.57) participated. Each participant was asked to select his or her most PLLs when listened to Korean ballade or dance music with an earbud or an over-the-ear earphone for 30 or 60 minutes. One side of earphone was connected to the participant's better ear and the other side was connected to a sound level meter via a 2 or 6 cc-couplers. Depending on earphone types, music genres, and listening durations, loudness A-weighted equivalent (LAeq) and loudness maximum time-weighted with A-frequency sound levels in dBA were measured. Neither main nor interaction effects of the PLLs among the three factors were significant. Overall output levels of earbuds were about 10-12 dBA greater than those of over-the-ear earphones. The PLLs were 1.73 dBA greater for earbuds than over-the-ear earphones. The average PLL for ballad was higher than for dance music. The PLLs at LAeq for both music genres were the greatest at 0.5 kHz followed by 1, 0.25, 2, 4, 0.125, 8 kHz in the order. The PLLs were not different significantly when listening to Korean ballad or dance music as functions of earphone types, music genres, and listening durations. However, over-the-ear earphones seemed to be more suitable to prevent noise induce hearing loss when listening to music, showing lower PLLs, possibly due to isolation from the background noise by covering ears.

  12. Comparison of P&O and INC Methods in Maximum Power Point Tracker for PV Systems

    Science.gov (United States)

    Chen, Hesheng; Cui, Yuanhui; Zhao, Yue; Wang, Zhisen

    2018-03-01

    In the context of renewable energy, the maximum power point tracker (MPPT) is often used to increase the solar power efficiency, taking into account the randomness and volatility of solar energy due to changes in temperature and photovoltaic. In all MPPT techniques, perturb & observe and incremental conductance are widely used in MPPT controllers, because of their simplicity and ease of operation. According to the internal structure of the photovoltaic cell and the output volt-ampere characteristic, this paper established the circuit model and establishes the dynamic simulation model in Matlab/Simulink with the preparation of the s function. The perturb & observe MPPT method and the incremental conductance MPPT method were analyzed and compared by the theoretical analysis and digital simulation. The simulation results have shown that the system with INC MPPT method has better dynamic performance and improves the output power of photovoltaic power generation.

  13. Sizing and control of trailing edge flaps on a smart rotor for maximum power generation in low fatigue wind regimes

    DEFF Research Database (Denmark)

    Smit, Jeroen; Bernhammer, Lars O.; Navalkar, Sachin T.

    2016-01-01

    to fatigue damage have been identified. In these regions, the turbine energy output can be increased by deflecting the trailing edge (TE) flap in order to track the maximum power coefficient as a function of local, instantaneous speed ratios. For this purpose, the TE flap configuration for maximum power...... generation has been using blade element momentum theory. As a first step, the operation in non-uniform wind field conditions was analysed. Firstly, the deterministic fluctuation in local tip speed ratio due to wind shear was evaluated. The second effect is associated with time delays in adapting the rotor...

  14. Maximum likelihood convolutional decoding (MCD) performance due to system losses

    Science.gov (United States)

    Webster, L.

    1976-01-01

    A model for predicting the computational performance of a maximum likelihood convolutional decoder (MCD) operating in a noisy carrier reference environment is described. This model is used to develop a subroutine that will be utilized by the Telemetry Analysis Program to compute the MCD bit error rate. When this computational model is averaged over noisy reference phase errors using a high-rate interpolation scheme, the results are found to agree quite favorably with experimental measurements.

  15. Kumaraswamy autoregressive moving average models for double bounded environmental data

    Science.gov (United States)

    Bayer, Fábio Mariano; Bayer, Débora Missio; Pumi, Guilherme

    2017-12-01

    In this paper we introduce the Kumaraswamy autoregressive moving average models (KARMA), which is a dynamic class of models for time series taking values in the double bounded interval (a,b) following the Kumaraswamy distribution. The Kumaraswamy family of distribution is widely applied in many areas, especially hydrology and related fields. Classical examples are time series representing rates and proportions observed over time. In the proposed KARMA model, the median is modeled by a dynamic structure containing autoregressive and moving average terms, time-varying regressors, unknown parameters and a link function. We introduce the new class of models and discuss conditional maximum likelihood estimation, hypothesis testing inference, diagnostic analysis and forecasting. In particular, we provide closed-form expressions for the conditional score vector and conditional Fisher information matrix. An application to environmental real data is presented and discussed.

  16. Monetary Policy and Industrial Output in the BRICS Countries: A Markov-Switching Model

    Directory of Open Access Journals (Sweden)

    Kutu Adebayo Augustine

    2017-12-01

    Full Text Available This paper examines whether the five BRICS countries share similar business cycles and determines the probability of any of the countries moving from a contractionary regime to an expansionary regime. The study further examines the extent to which changes in monetary policy affect industrial output in expansions relative to contractions. Employing the Peersman and Smets (2001 Markov-Switching Model (MSM and monthly data from 1994.01–2013.12, the study reveals that the five BRICS countries have similar business cycles. The results further demonstrate that the BRICS countries’ business cycles are characterized by two distinct growth rate phases: a contractionary regime and an expansionary regime. It can also be observed that the area-wide monetary policy has significantly large effects on industrial output in recessions as well as in booms. It has also been established that there is a high probability of moving from state one (recession to state two (expansion and that on average, the probabilities of staying in state 2 (expansion are high for each of the five countries. It is, therefore, recommended that the BRICS countries should sustain uniform policy consistency (monetary policy, especially as they formulate and implement economic policies to stimulate industrial output.

  17. Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

    Directory of Open Access Journals (Sweden)

    Ahmed M. Othman

    2012-12-01

    Full Text Available In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV systems. Maximum power point tracking (MPPT plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O algorithm and is compared to a designed fuzzy logic controller (FLC. The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

  18. Relationships among peak power output, peak bar velocity, and mechanomyographic amplitude during the free-weight bench press exercise.

    Science.gov (United States)

    Stock, Matt S; Beck, Travis W; Defreitas, Jason M; Dillon, Michael A

    2010-10-01

    The purpose of this study was to examine the relationships among mechanomyographic (MMG) amplitude, power output, and bar velocity during the free-weight bench press exercise. Twenty-one resistance-trained men [one-repetition maximum (1-RM) bench press = 125.4+18.4 kg] performed bench press muscle actions as explosively as possible from 10% to 90% of the 1-RM while peak power output and peak bar velocity were assessed with a TENDO Weightlifting Analyzer. During each muscle action, surface MMG signals were detected from the right and left pectoralis major and triceps brachii, and the concentric portion of the range of motion was selected for analysis. Results indicated that power output increased from 10% to 50% 1-RM, followed by decreases from 50% to 90% 1-RM, but MMG amplitude for each of the muscles increased from 10 to 80% 1-RM. The results of this study indicate that during the free-weight bench press exercise, MMG amplitude was not related to power output, but was inversely related to bar velocity and directly related to the external load being lifted. In future research, coaches and sport scientists may be able to estimate force/torque production from individual muscles during multi-joint, dynamic constant external resistance muscle actions.

  19. WRF Model Output

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains WRF model output. There are three months of data: July 2012, July 2013, and January 2013. For each month, several simulations were made: A...

  20. The input and output management of solid waste using DEA models: A case study at Jengka, Pahang

    Science.gov (United States)

    Mohamed, Siti Rosiah; Ghazali, Nur Fadzrina Mohd; Mohd, Ainun Hafizah

    2017-08-01

    Data Envelopment Analysis (DEA) as a tool for obtaining performance indices has been used extensively in several of organizations sector. The ways to improve the efficiency of Decision Making Units (DMUs) is impractical because some of inputs and outputs are uncontrollable and in certain situation its produce weak efficiency which often reflect the impact for operating environment. Based on the data from Alam Flora Sdn. Bhd Jengka, the researcher wants to determine the efficiency of solid waste management (SWM) in town Jengka Pahang using CCRI and CCRO model of DEA and duality formulation with vector average input and output. Three input variables (length collection in meter, frequency time per week in hour and number of garbage truck) and 2 outputs variables (frequency collection and the total solid waste collection in kilogram) are analyzed. As a conclusion, it shows only three roads from 23 roads are efficient that achieve efficiency score 1. Meanwhile, 20 other roads are in an inefficient management.

  1. Redesign lifts prep output 288%

    Energy Technology Data Exchange (ETDEWEB)

    Hamric, J

    1987-02-01

    This paper outlines the application of engineering creativity and how it brought output at an Ohio coal preparation plant up from 12,500 tpd to nearly four times that figure, 48,610 tpd. By streamlining the conveyor systems, removing surplus belt length and repositioning subplants the whole operation was able to run far more efficiently with a greater output. Various other alterations including the raw material supply and management and operating practices were also undertaken to provide a test for the achievements possible with such reorganization. The new developments have been in the following fields: fine coal cleaning, heavy media cyclones, feeders, bins, filter presses, dewatering equipment and settling tanks. Output is now limited only by the reduced demand by the Gavin power station nearby.

  2. Output Information Based Fault-Tolerant Iterative Learning Control for Dual-Rate Sampling Process with Disturbances and Output Delay

    Directory of Open Access Journals (Sweden)

    Hongfeng Tao

    2018-01-01

    Full Text Available For a class of single-input single-output (SISO dual-rate sampling processes with disturbances and output delay, this paper presents a robust fault-tolerant iterative learning control algorithm based on output information. Firstly, the dual-rate sampling process with output delay is transformed into discrete system in state-space model form with slow sampling rate without time delay by using lifting technology; then output information based fault-tolerant iterative learning control scheme is designed and the control process is turned into an equivalent two-dimensional (2D repetitive process. Moreover, based on the repetitive process stability theory, the sufficient conditions for the stability of system and the design method of robust controller are given in terms of linear matrix inequalities (LMIs technique. Finally, the flow control simulations of two flow tanks in series demonstrate the feasibility and effectiveness of the proposed method.

  3. Study of nominal daily output of urine from workers

    International Nuclear Information System (INIS)

    Lima, Marina F.; Carneiro, Janete C.G. Gaburo; Todo, Alberto S.

    2007-01-01

    A retrospective study of the 24-hour urine volumes from workers selected for the internal individual monitoring compares the average volume collected by sample and the average volume per individual with the nominal daily output of urine from 'Reference Man'. This work considers 134 registers of urine samples from 18 male workers, with semester routine sampling, between the years of 2000 and 2005. For this group, the average volume per collection was (971±371)mL and (962±376)mL per individual. In a cohort group of 9 male workers, which supplied at least 10 samples in this period, it was observed that the average volume per collection decreased to (955±308)mL and the average volume per individual increased to (1027±400)mL. For the female group, composed by 11 individuals, the 29 urine samples supplied between 1999 and 2005 were considered. The average volume per sampling and for worker was, respectively, (1122±337)mL and (1105±337)mL. Another cohort group of only 4 female workers with at least one annual collection during five years, of the seven years considered, the values decreased to (1112±336)mL per collection and the average volume per individual was maintained. The major variability of the volume among all the individuals was 927%, and for the same individual was 562%. This difference can be indicative of the individual differences of retention and excretion, alimentary diet interferences and for lack of awareness by the individual to collect urine during a period of 24-hour. The radionuclides clearance does not occur in constant rates and for the purpose of assessing intakes, in our routine analysis, the total volume of urine from worker is corrected for 1,4 L. Based in the results obtained over the years, and to minimize the errors of the nominal daily excretion rate in urine, actions about the aware of the individual in carrying out an accurately sampling and/or the implementation of the measurements of creatinine levels in urine are suggested

  4. Space-Time Chip Equalization for Maximum Diversity Space-Time Block Coded DS-CDMA Downlink Transmission

    Directory of Open Access Journals (Sweden)

    Petré Frederik

    2004-01-01

    Full Text Available In the downlink of DS-CDMA, frequency-selectivity destroys the orthogonality of the user signals and introduces multiuser interference (MUI. Space-time chip equalization is an efficient tool to restore the orthogonality of the user signals and suppress the MUI. Furthermore, multiple-input multiple-output (MIMO communication techniques can result in a significant increase in capacity. This paper focuses on space-time block coding (STBC techniques, and aims at combining STBC techniques with the original single-antenna DS-CDMA downlink scheme. This results into the so-called space-time block coded DS-CDMA downlink schemes, many of which have been presented in the past. We focus on a new scheme that enables both the maximum multiantenna diversity and the maximum multipath diversity. Although this maximum diversity can only be collected by maximum likelihood (ML detection, we pursue suboptimal detection by means of space-time chip equalization, which lowers the computational complexity significantly. To design the space-time chip equalizers, we also propose efficient pilot-based methods. Simulation results show improved performance over the space-time RAKE receiver for the space-time block coded DS-CDMA downlink schemes that have been proposed for the UMTS and IS-2000 W-CDMA standards.

  5. CMAQ Model Output

    Data.gov (United States)

    U.S. Environmental Protection Agency — CMAQ and CMAQ-VBS model output. This dataset is not publicly accessible because: Files too large. It can be accessed through the following means: via EPA's NCC tape...

  6. An Improvement of a Fuzzy Logic-Controlled Maximum Power Point Tracking Algorithm for Photovoltic Applications

    Directory of Open Access Journals (Sweden)

    Woonki Na

    2017-03-01

    Full Text Available This paper presents an improved maximum power point tracking (MPPT algorithm using a fuzzy logic controller (FLC in order to extract potential maximum power from photovoltaic cells. The objectives of the proposed algorithm are to improve the tracking speed, and to simultaneously solve the inherent drawbacks such as slow tracking in the conventional perturb and observe (P and O algorithm. The performances of the conventional P and O algorithm and the proposed algorithm are compared by using MATLAB/Simulink in terms of the tracking speed and steady-state oscillations. Additionally, both algorithms were experimentally validated through a digital signal processor (DSP-based controlled-boost DC-DC converter. The experimental results show that the proposed algorithm performs with a shorter tracking time, smaller output power oscillation, and higher efficiency, compared with the conventional P and O algorithm.

  7. Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

    Directory of Open Access Journals (Sweden)

    Jairo Vázquez-Guerrero

    Full Text Available The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P < 0.010 and peak force output differed between all loads for each condition (P < 0.045. Mean force outputs were greater in the concentric than in the eccentric phase under both conditions and with all loads (P < 0.001. There were no significant differences in peak force between concentric and eccentric phases at any load in either stable or unstable conditions. In conclusion, squatting with a rotational inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

  8. Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

    Science.gov (United States)

    Vázquez-Guerrero, Jairo; Moras, Gerard; Baeza, Jennifer; Rodríguez-Jiménez, Sergio

    2016-01-01

    The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg) were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

  9. Output controllability of nonlinear systems with bounded control

    International Nuclear Information System (INIS)

    Garcia, Rafael; D'Attellis, Carlos

    1990-01-01

    The control problem treated in this paper is the output controllability of a nonlinear system in the form: x = f(x) + g(x)u(t); y = h(x), using bounded controls. The approach to the problem consists of a modification in the system using dynamic feedback in such a way that the input/output behaviour of the closed loop matches the input/output behaviour of a completely output-controllable system with bounded controls. Sufficient conditions are also put forward on the system so that a compact set in the output space may be reached in finite time using uniformally bounded controls, and a result on output regulation in finite time with asymptotic state stabilization is obtained. (Author)

  10. Hierarchical Load Tracking Control of a Grid-connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

    DEFF Research Database (Denmark)

    Li, Yonghui; Wu, Qiuwei; Zhu, Haiyu

    2015-01-01

    efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active...... power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model......Based on the benchmark solid oxide fuel cell (SOFC) dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP) optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject...

  11. A Monte Carlo Study on Multiple Output Stochastic Frontiers

    DEFF Research Database (Denmark)

    Henningsen, Géraldine; Henningsen, Arne; Jensen, Uwe

    , dividing all other output quantities by the selected output quantity, and using these ratios as regressors (OD). Another approach is the stochastic ray production frontier (SR) which transforms the output quantities into their Euclidean distance as the dependent variable and their polar coordinates......In the estimation of multiple output technologies in a primal approach, the main question is how to handle the multiple outputs. Often an output distance function is used, where the classical approach is to exploit its homogeneity property by selecting one output quantity as the dependent variable...... of both specifications for the case of a Translog output distance function with respect to different common statistical problems as well as problems arising as a consequence of zero values in the output quantities. Although, our results partly show clear reactions to statistical misspecifications...

  12. Half-Watt average power femtosecond source spanning 3-8 µm based on subharmonic generation in GaAs

    Science.gov (United States)

    Smolski, Viktor; Vasilyev, Sergey; Moskalev, Igor; Mirov, Mike; Ru, Qitian; Muraviev, Andrey; Schunemann, Peter; Mirov, Sergey; Gapontsev, Valentin; Vodopyanov, Konstantin

    2018-06-01

    Frequency combs with a wide instantaneous spectral span covering the 3-20 µm molecular fingerprint region are highly desirable for broadband and high-resolution frequency comb spectroscopy, trace molecular detection, and remote sensing. We demonstrate a novel approach for generating high-average-power middle-infrared (MIR) output suitable for producing frequency combs with an instantaneous spectral coverage close to 1.5 octaves. Our method is based on utilizing a highly-efficient and compact Kerr-lens mode-locked Cr2+:ZnS laser operating at 2.35-µm central wavelength with 6-W average power, 77-fs pulse duration, and high 0.9-GHz repetition rate; to pump a degenerate (subharmonic) optical parametric oscillator (OPO) based on a quasi-phase-matched GaAs crystal. Such subharmonic OPO is a nearly ideal frequency converter capable of extending the benefits of frequency combs based on well-established mode-locked pump lasers to the MIR region through rigorous, phase- and frequency-locked down conversion. We report a 0.5-W output in the form of an ultra-broadband spectrum spanning 3-8 µm measured at 50-dB level.

  13. Step Test: a method for evaluating maximum oxygen consumption to determine the ability kind of work among students of medical emergencies.

    Science.gov (United States)

    Heydari, Payam; Varmazyar, Sakineh; Nikpey, Ahmad; Variani, Ali Safari; Jafarvand, Mojtaba

    2017-03-01

    Maximum oxygen consumption shows the maximum oxygen rate of muscle oxygenation that is acceptable in many cases, to measure the fitness between person and the desired job. Given that medical emergencies are important, and difficult jobs in emergency situations require people with high physical ability and readiness for the job, the aim of this study was to evaluate the maximum oxygen consumption, to determine the ability of work type among students of medical emergencies in Qazvin in 2016. This study was a descriptive - analytical, and in cross-sectional type conducted among 36 volunteer students of medical emergencies in Qazvin in 2016. After necessary coordination for the implementation of the study, participants completed health questionnaires and demographic characteristics and then the participants were evaluated with step tests of American College of Sport Medicine (ACSM). Data analysis was done by SPSS version 18 and U-Mann-Whitney tests, Kruskal-Wallis and Pearson correlation coefficient. Average of maximum oxygen consumption of the participants was estimated 3.15±0.50 liters per minute. 91.7% of medical emergencies students were selected as appropriate in terms of maximum oxygen consumption and thus had the ability to do heavy and too heavy work. Average of maximum oxygen consumption evaluated by the U-Mann-Whitney test and Kruskal-Wallis, had significant relationship with age (p<0.05) and weight groups (p<0.001). There was a significant positive correlation between maximum oxygen consumption with weight and body mass index (p<0.001). The results of this study showed that demographic variables of weight and body mass index are the factors influencing the determination of maximum oxygen consumption, as most of the students had the ability to do heavy, and too heavy work. Therefore, people with ability to do average work are not suitable for medical emergency tasks.

  14. Tracking the global maximum power point of PV arrays under partial shading conditions

    Science.gov (United States)

    Fennich, Meryem

    This thesis presents the theoretical and simulation studies of the global maximum power point tracking (MPPT) for photovoltaic systems under partial shading. The main goal is to track the maximum power point of the photovoltaic module so that the maximum possible power can be extracted from the photovoltaic panels. When several panels are connected in series with some of them shaded partially either due to clouds or shadows from neighboring buildings, several local maxima appear in the power vs. voltage curve. A power increment based MPPT algorithm is effective in identifying the global maximum from the several local maxima. Several existing MPPT algorithms are explored and the state-of-the-art power increment method is simulated and tested for various partial shading conditions. The current-voltage and power-voltage characteristics of the PV model are studied under different partial shading conditions, along with five different cases demonstrating how the MPPT algorithm performs when shading switches from one state to another. Each case is supplemented with simulation results. The method of tracking the Global MPP is based on controlling the DC-DC converter connected to the output of the PV array. A complete system simulation including the PV array, the direct current to direct current (DC-DC) converter and the MPPT is presented and tested using MATLAB software. The simulation results show that the MPPT algorithm works very well with the buck converter, while the boost converter needs further changes and implementation.

  15. A simple maximum power point tracker for thermoelectric generators

    International Nuclear Information System (INIS)

    Paraskevas, Alexandros; Koutroulis, Eftichios

    2016-01-01

    Highlights: • A Maximum Power Point Tracking (MPPT) method for thermoelectric generators is proposed. • A power converter is controlled to operate on a pre-programmed locus. • The proposed MPPT technique has the advantage of operational and design simplicity. • The experimental average deviation from the MPP power of the TEG source is 1.87%. - Abstract: ThermoElectric Generators (TEGs) are capable to harvest the ambient thermal energy for power-supplying sensors, actuators, biomedical devices etc. in the μW up to several hundreds of Watts range. In this paper, a Maximum Power Point Tracking (MPPT) method for TEG elements is proposed, which is based on controlling a power converter such that it operates on a pre-programmed locus of operating points close to the MPPs of the power–voltage curves of the TEG power source. Compared to the past-proposed MPPT methods for TEGs, the technique presented in this paper has the advantage of operational and design simplicity. Thus, its implementation using off-the-shelf microelectronic components with low-power consumption characteristics is enabled, without being required to employ specialized integrated circuits or signal processing units of high development cost. Experimental results are presented, which demonstrate that for MPP power levels of the TEG source in the range of 1–17 mW, the average deviation of the power produced by the proposed system from the MPP power of the TEG source is 1.87%.

  16. 53 W average power few-cycle fiber laser system generating soft x rays up to the water window.

    Science.gov (United States)

    Rothhardt, Jan; Hädrich, Steffen; Klenke, Arno; Demmler, Stefan; Hoffmann, Armin; Gotschall, Thomas; Eidam, Tino; Krebs, Manuel; Limpert, Jens; Tünnermann, Andreas

    2014-09-01

    We report on a few-cycle laser system delivering sub-8-fs pulses with 353 μJ pulse energy and 25 GW of peak power at up to 150 kHz repetition rate. The corresponding average output power is as high as 53 W, which represents the highest average power obtained from any few-cycle laser architecture so far. The combination of both high average and high peak power provides unique opportunities for applications. We demonstrate high harmonic generation up to the water window and record-high photon flux in the soft x-ray spectral region. This tabletop source of high-photon flux soft x rays will, for example, enable coherent diffractive imaging with sub-10-nm resolution in the near future.

  17. State Averages

    Data.gov (United States)

    U.S. Department of Health & Human Services — A list of a variety of averages for each state or territory as well as the national average, including each quality measure, staffing, fine amount and number of...

  18. A Markovian model of evolving world input-output network.

    Directory of Open Access Journals (Sweden)

    Vahid Moosavi

    Full Text Available The initial theoretical connections between Leontief input-output models and Markov chains were established back in 1950s. However, considering the wide variety of mathematical properties of Markov chains, so far there has not been a full investigation of evolving world economic networks with Markov chain formalism. In this work, using the recently available world input-output database, we investigated the evolution of the world economic network from 1995 to 2011 through analysis of a time series of finite Markov chains. We assessed different aspects of this evolving system via different known properties of the Markov chains such as mixing time, Kemeny constant, steady state probabilities and perturbation analysis of the transition matrices. First, we showed how the time series of mixing times and Kemeny constants could be used as an aggregate index of globalization. Next, we focused on the steady state probabilities as a measure of structural power of the economies that are comparable to GDP shares of economies as the traditional index of economies welfare. Further, we introduced two measures of systemic risk, called systemic influence and systemic fragility, where the former is the ratio of number of influenced nodes to the total number of nodes, caused by a shock in the activity of a node, and the latter is based on the number of times a specific economic node is affected by a shock in the activity of any of the other nodes. Finally, focusing on Kemeny constant as a global indicator of monetary flow across the network, we showed that there is a paradoxical effect of a change in activity levels of economic nodes on the overall flow of the world economic network. While the economic slowdown of the majority of nodes with high structural power results to a slower average monetary flow over the network, there are some nodes, where their slowdowns improve the overall quality of the network in terms of connectivity and the average flow of the money.

  19. A Markovian model of evolving world input-output network.

    Science.gov (United States)

    Moosavi, Vahid; Isacchini, Giulio

    2017-01-01

    The initial theoretical connections between Leontief input-output models and Markov chains were established back in 1950s. However, considering the wide variety of mathematical properties of Markov chains, so far there has not been a full investigation of evolving world economic networks with Markov chain formalism. In this work, using the recently available world input-output database, we investigated the evolution of the world economic network from 1995 to 2011 through analysis of a time series of finite Markov chains. We assessed different aspects of this evolving system via different known properties of the Markov chains such as mixing time, Kemeny constant, steady state probabilities and perturbation analysis of the transition matrices. First, we showed how the time series of mixing times and Kemeny constants could be used as an aggregate index of globalization. Next, we focused on the steady state probabilities as a measure of structural power of the economies that are comparable to GDP shares of economies as the traditional index of economies welfare. Further, we introduced two measures of systemic risk, called systemic influence and systemic fragility, where the former is the ratio of number of influenced nodes to the total number of nodes, caused by a shock in the activity of a node, and the latter is based on the number of times a specific economic node is affected by a shock in the activity of any of the other nodes. Finally, focusing on Kemeny constant as a global indicator of monetary flow across the network, we showed that there is a paradoxical effect of a change in activity levels of economic nodes on the overall flow of the world economic network. While the economic slowdown of the majority of nodes with high structural power results to a slower average monetary flow over the network, there are some nodes, where their slowdowns improve the overall quality of the network in terms of connectivity and the average flow of the money.

  20. Fast multi-output relevance vector regression

    OpenAIRE

    Ha, Youngmin

    2017-01-01

    This paper aims to decrease the time complexity of multi-output relevance vector regression from O(VM^3) to O(V^3+M^3), where V is the number of output dimensions, M is the number of basis functions, and V

  1. Flow Control in Wells Turbines for Harnessing Maximum Wave Power

    Science.gov (United States)

    Garrido, Aitor J.; Garrido, Izaskun; Otaola, Erlantz; Maseda, Javier

    2018-01-01

    Oceans, and particularly waves, offer a huge potential for energy harnessing all over the world. Nevertheless, the performance of current energy converters does not yet allow us to use the wave energy efficiently. However, new control techniques can improve the efficiency of energy converters. In this sense, the plant sensors play a key role within the control scheme, as necessary tools for parameter measuring and monitoring that are then used as control input variables to the feedback loop. Therefore, the aim of this work is to manage the rotational speed control loop in order to optimize the output power. With the help of outward looking sensors, a Maximum Power Point Tracking (MPPT) technique is employed to maximize the system efficiency. Then, the control decisions are based on the pressure drop measured by pressure sensors located along the turbine. A complete wave-to-wire model is developed so as to validate the performance of the proposed control method. For this purpose, a novel sensor-based flow controller is implemented based on the different measured signals. Thus, the performance of the proposed controller has been analyzed and compared with a case of uncontrolled plant. The simulations demonstrate that the flow control-based MPPT strategy is able to increase the output power, and they confirm both the viability and goodness. PMID:29439408

  2. Flow Control in Wells Turbines for Harnessing Maximum Wave Power.

    Science.gov (United States)

    Lekube, Jon; Garrido, Aitor J; Garrido, Izaskun; Otaola, Erlantz; Maseda, Javier

    2018-02-10

    Oceans, and particularly waves, offer a huge potential for energy harnessing all over the world. Nevertheless, the performance of current energy converters does not yet allow us to use the wave energy efficiently. However, new control techniques can improve the efficiency of energy converters. In this sense, the plant sensors play a key role within the control scheme, as necessary tools for parameter measuring and monitoring that are then used as control input variables to the feedback loop. Therefore, the aim of this work is to manage the rotational speed control loop in order to optimize the output power. With the help of outward looking sensors, a Maximum Power Point Tracking (MPPT) technique is employed to maximize the system efficiency. Then, the control decisions are based on the pressure drop measured by pressure sensors located along the turbine. A complete wave-to-wire model is developed so as to validate the performance of the proposed control method. For this purpose, a novel sensor-based flow controller is implemented based on the different measured signals. Thus, the performance of the proposed controller has been analyzed and compared with a case of uncontrolled plant. The simulations demonstrate that the flow control-based MPPT strategy is able to increase the output power, and they confirm both the viability and goodness.

  3. Chaotic Universe, Friedmannian on the average 2

    Energy Technology Data Exchange (ETDEWEB)

    Marochnik, L S [AN SSSR, Moscow. Inst. Kosmicheskikh Issledovanij

    1980-11-01

    The cosmological solutions are found for the equations for correlators, describing a statistically chaotic Universe, Friedmannian on the average in which delta-correlated fluctuations with amplitudes h >> 1 are excited. For the equation of state of matter p = n epsilon, the kind of solutions depends on the position of maximum of the spectrum of the metric disturbances. The expansion of the Universe, in which long-wave potential and vortical motions and gravitational waves (modes diverging at t ..-->.. 0) had been excited, tends asymptotically to the Friedmannian one at t ..-->.. identity and depends critically on n: at n < 0.26, the solution for the scalefactor is situated higher than the Friedmannian one, and lower at n > 0.26. The influence of finite at t ..-->.. 0 long-wave fluctuation modes leads to an averaged quasiisotropic solution. The contribution of quantum fluctuations and of short-wave parts of the spectrum of classical fluctuations to the expansion law is considered. Their influence is equivalent to the contribution from an ultrarelativistic gas with corresponding energy density and pressure. The restrictions are obtained for the degree of chaos (the spectrum characteristics) compatible with the observed helium abundance, which could have been retained by a completely chaotic Universe during its expansion up to the nucleosynthesis epoch.

  4. Commissioning of output factors for uniform scanning proton beams

    International Nuclear Information System (INIS)

    Zheng Yuanshui; Ramirez, Eric; Mascia, Anthony; Ding Xiaoning; Okoth, Benny; Zeidan, Omar; Hsi Wen; Harris, Ben; Schreuder, Andries N.; Keole, Sameer

    2011-01-01

    Purpose: Current commercial treatment planning systems are not able to accurately predict output factors and calculate monitor units for proton fields. Patient-specific field output factors are thus determined by either measurements or empirical modeling based on commissioning data. The objective of this study is to commission output factors for uniform scanning beams utilized at the ProCure proton therapy centers. Methods: Using water phantoms and a plane parallel ionization chamber, the authors first measured output factors with a fixed 10 cm diameter aperture as a function of proton range and modulation width for clinically available proton beams with ranges between 4 and 31.5 cm and modulation widths between 2 and 15 cm. The authors then measured the output factor as a function of collimated field size at various calibration depths for proton beams of various ranges and modulation widths. The authors further examined the dependence of the output factor on the scanning area (i.e., uncollimated proton field), snout position, and phantom material. An empirical model was developed to calculate the output factor for patient-specific fields and the model-predicted output factors were compared to measurements. Results: The output factor increased with proton range and field size, and decreased with modulation width. The scanning area and snout position have a small but non-negligible effect on the output factors. The predicted output factors based on the empirical modeling agreed within 2% of measurements for all prostate treatment fields and within 3% for 98.5% of all treatment fields. Conclusions: Comprehensive measurements at a large subset of available beam conditions are needed to commission output factors for proton therapy beams. The empirical modeling agrees well with the measured output factor data. This investigation indicates that it is possible to accurately predict output factors and thus eliminate or reduce time-consuming patient-specific output

  5. Experimental demonstration of multiple-inputs multiple-outputs OFDM/OQAM visible light communications

    Science.gov (United States)

    Lin, Bangjiang; Tang, Xuan; Ghassemlooy, Zabih; Lin, Chun; Zhang, Min

    2017-10-01

    We experimentally demonstrate a 2×2 optical multiple-inputs multiple-outputs (MIMO) visible light communications system based on the modified orthogonal frequency-division multiplexing/offset quadrature amplitude modulation scheme. The adjacent subcarrier frequency-domain averaging (ASFA) with the full-loaded (FL) and half-loaded (HL) preamble structures is proposed for demultiplexing and mitigating the intrinsic imaginary interference (IMI) effect. Compared with the conventional channel estimation (CE) method, ASFA offers improved transmission performance. With the FL method, we obtain more accurate MIMO CE to mitigate the IMI effect and the optical noise compared to the HL method.

  6. Evaluation of input output efficiency of oil field considering undesirable output —A case study of sandstone reservoir in Xinjiang oilfield

    Science.gov (United States)

    Zhang, Shuying; Wu, Xuquan; Li, Deshan; Xu, Yadong; Song, Shulin

    2017-06-01

    Based on the input and output data of sandstone reservoir in Xinjiang oilfield, the SBM-Undesirable model is used to study the technical efficiency of each block. Results show that: the model of SBM-undesirable to evaluate its efficiency and to avoid defects caused by traditional DEA model radial angle, improve the accuracy of the efficiency evaluation. by analyzing the projection of the oil blocks, we find that each block is in the negative external effects of input redundancy and output deficiency benefit and undesirable output, and there are greater differences in the production efficiency of each block; the way to improve the input-output efficiency of oilfield is to optimize the allocation of resources, reduce the undesirable output and increase the expected output.

  7. THESEUS: maximum likelihood superpositioning and analysis of macromolecular structures.

    Science.gov (United States)

    Theobald, Douglas L; Wuttke, Deborah S

    2006-09-01

    THESEUS is a command line program for performing maximum likelihood (ML) superpositions and analysis of macromolecular structures. While conventional superpositioning methods use ordinary least-squares (LS) as the optimization criterion, ML superpositions provide substantially improved accuracy by down-weighting variable structural regions and by correcting for correlations among atoms. ML superpositioning is robust and insensitive to the specific atoms included in the analysis, and thus it does not require subjective pruning of selected variable atomic coordinates. Output includes both likelihood-based and frequentist statistics for accurate evaluation of the adequacy of a superposition and for reliable analysis of structural similarities and differences. THESEUS performs principal components analysis for analyzing the complex correlations found among atoms within a structural ensemble. ANSI C source code and selected binaries for various computing platforms are available under the GNU open source license from http://monkshood.colorado.edu/theseus/ or http://www.theseus3d.org.

  8. Applications of the maximum entropy principle in nuclear physics

    International Nuclear Information System (INIS)

    Froehner, F.H.

    1990-01-01

    Soon after the advent of information theory the principle of maximum entropy was recognized as furnishing the missing rationale for the familiar rules of classical thermodynamics. More recently it has also been applied successfully in nuclear physics. As an elementary example we derive a physically meaningful macroscopic description of the spectrum of neutrons emitted in nuclear fission, and compare the well known result with accurate data on 252 Cf. A second example, derivation of an expression for resonance-averaged cross sections for nuclear reactions like scattering or fission, is less trivial. Entropy maximization, constrained by given transmission coefficients, yields probability distributions for the R- and S-matrix elements, from which average cross sections can be calculated. If constrained only by the range of the spectrum of compound-nuclear levels it produces the Gaussian Orthogonal Ensemble (GOE) of Hamiltonian matrices that again yields expressions for average cross sections. Both avenues give practically the same numbers in spite of the quite different cross section formulae. These results were employed in a new model-aided evaluation of the 238 U neutron cross sections in the unresolved resonance region. (orig.) [de

  9. Average subentropy, coherence and entanglement of random mixed quantum states

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lin, E-mail: godyalin@163.com [Institute of Mathematics, Hangzhou Dianzi University, Hangzhou 310018 (China); Singh, Uttam, E-mail: uttamsingh@hri.res.in [Harish-Chandra Research Institute, Allahabad, 211019 (India); Pati, Arun K., E-mail: akpati@hri.res.in [Harish-Chandra Research Institute, Allahabad, 211019 (India)

    2017-02-15

    Compact expressions for the average subentropy and coherence are obtained for random mixed states that are generated via various probability measures. Surprisingly, our results show that the average subentropy of random mixed states approaches the maximum value of the subentropy which is attained for the maximally mixed state as we increase the dimension. In the special case of the random mixed states sampled from the induced measure via partial tracing of random bipartite pure states, we establish the typicality of the relative entropy of coherence for random mixed states invoking the concentration of measure phenomenon. Our results also indicate that mixed quantum states are less useful compared to pure quantum states in higher dimension when we extract quantum coherence as a resource. This is because of the fact that average coherence of random mixed states is bounded uniformly, however, the average coherence of random pure states increases with the increasing dimension. As an important application, we establish the typicality of relative entropy of entanglement and distillable entanglement for a specific class of random bipartite mixed states. In particular, most of the random states in this specific class have relative entropy of entanglement and distillable entanglement equal to some fixed number (to within an arbitrary small error), thereby hugely reducing the complexity of computation of these entanglement measures for this specific class of mixed states.

  10. Allometries of Maximum Growth Rate versus Body Mass at Maximum Growth Indicate That Non-Avian Dinosaurs Had Growth Rates Typical of Fast Growing Ectothermic Sauropsids

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

    We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes) strongly differed from Case’s study (1978), which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles) to 20 (fishes) times (in comparison to mammals) or even 45 (reptiles) to 100 (fishes) times (in comparison to birds) lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule out either

  11. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

    We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes) strongly differed from Case's study (1978), which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles) to 20 (fishes) times (in comparison to mammals) or even 45 (reptiles) to 100 (fishes) times (in comparison to birds) lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule out either of

  12. Allometries of maximum growth rate versus body mass at maximum growth indicate that non-avian dinosaurs had growth rates typical of fast growing ectothermic sauropsids.

    Directory of Open Access Journals (Sweden)

    Jan Werner

    Full Text Available We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes strongly differed from Case's study (1978, which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles to 20 (fishes times (in comparison to mammals or even 45 (reptiles to 100 (fishes times (in comparison to birds lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule

  13. Statistical Downscaling and Bias Correction of Climate Model Outputs for Climate Change Impact Assessment in the U.S. Northeast

    Science.gov (United States)

    Ahmed, Kazi Farzan; Wang, Guiling; Silander, John; Wilson, Adam M.; Allen, Jenica M.; Horton, Radley; Anyah, Richard

    2013-01-01

    Statistical downscaling can be used to efficiently downscale a large number of General Circulation Model (GCM) outputs to a fine temporal and spatial scale. To facilitate regional impact assessments, this study statistically downscales (to 1/8deg spatial resolution) and corrects the bias of daily maximum and minimum temperature and daily precipitation data from six GCMs and four Regional Climate Models (RCMs) for the northeast United States (US) using the Statistical Downscaling and Bias Correction (SDBC) approach. Based on these downscaled data from multiple models, five extreme indices were analyzed for the future climate to quantify future changes of climate extremes. For a subset of models and indices, results based on raw and bias corrected model outputs for the present-day climate were compared with observations, which demonstrated that bias correction is important not only for GCM outputs, but also for RCM outputs. For future climate, bias correction led to a higher level of agreements among the models in predicting the magnitude and capturing the spatial pattern of the extreme climate indices. We found that the incorporation of dynamical downscaling as an intermediate step does not lead to considerable differences in the results of statistical downscaling for the study domain.

  14. Output Control Using Feedforward And Cascade Controllers

    Science.gov (United States)

    Seraji, Homayoun

    1990-01-01

    Report presents theoretical study of open-loop control elements in single-input, single-output linear system. Focus on output-control (servomechanism) problem, in which objective is to find control scheme that causes output to track certain command inputs and to reject certain disturbance inputs in steady state. Report closes with brief discussion of characteristics and relative merits of feedforward, cascade, and feedback controllers and combinations thereof.

  15. Proton transport properties of poly(aspartic acid) with different average molecular weights

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Yuki, E-mail: ynagao@kuchem.kyoto-u.ac.j [Department of Mechanical Systems and Design, Graduate School of Engineering, Tohoku University, 6-6-01 Aoba Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Imai, Yuzuru [Institute of Development, Aging and Cancer (IDAC), Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai 980-8575 (Japan); Matsui, Jun [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Sendai 980-8577 (Japan); Ogawa, Tomoyuki [Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Miyashita, Tokuji [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Sendai 980-8577 (Japan)

    2011-04-15

    Research highlights: Seven polymers with different average molecular weights were synthesized. The proton conductivity depended on the number-average degree of polymerization. The difference of the proton conductivities was more than one order of magnitude. The number-average molecular weight contributed to the stability of the polymer. - Abstract: We synthesized seven partially protonated poly(aspartic acids)/sodium polyaspartates (P-Asp) with different average molecular weights to study their proton transport properties. The number-average degree of polymerization (DP) for each P-Asp was 30 (P-Asp30), 115 (P-Asp115), 140 (P-Asp140), 160 (P-Asp160), 185 (P-Asp185), 205 (P-Asp205), and 250 (P-Asp250). The proton conductivity depended on the number-average DP. The maximum and minimum proton conductivities under a relative humidity of 70% and 298 K were 1.7 . 10{sup -3} S cm{sup -1} (P-Asp140) and 4.6 . 10{sup -4} S cm{sup -1} (P-Asp250), respectively. Differential thermogravimetric analysis (TG-DTA) was carried out for each P-Asp. The results were classified into two categories. One exhibited two endothermic peaks between t = (270 and 300) {sup o}C, the other exhibited only one peak. The P-Asp group with two endothermic peaks exhibited high proton conductivity. The high proton conductivity is related to the stability of the polymer. The number-average molecular weight also contributed to the stability of the polymer.

  16. Tracking 20 years of compound-to-target output from literature and patents.

    Directory of Open Access Journals (Sweden)

    Christopher Southan

    Full Text Available The statistics of drug development output and declining yield of approved medicines has been the subject of many recent reviews. However, assessing research productivity that feeds development is more difficult. Here we utilise an extensive database of structure-activity relationships extracted from papers and patents. We have used this database to analyse published compounds cumulatively linked to nearly 4000 protein target identifiers from multiple species over the last 20 years. The compound output increases up to 2005 followed by a decline that parallels a fall in pharmaceutical patenting. Counts of protein targets have plateaued but not fallen. We extended these results by exploring compounds and targets for one large pharmaceutical company. In addition, we examined collective time course data for six individual protease targets, including average molecular weight of the compounds. We also tracked the PubMed profile of these targets to detect signals related to changes in compound output. Our results show that research compound output had decreased 35% by 2012. The major causative factor is likely to be a contraction in the global research base due to mergers and acquisitions across the pharmaceutical industry. However, this does not rule out an increasing stringency of compound quality filtration and/or patenting cost control. The number of proteins mapped to compounds on a yearly basis shows less decline, indicating the cumulative published target capacity of global research is being sustained in the region of 300 proteins for large companies. The tracking of six individual targets shows uniquely detailed patterns not discernible from cumulative snapshots. These are interpretable in terms of events related to validation and de-risking of targets that produce detectable follow-on surges in patenting. Further analysis of the type we present here can provide unique insights into the process of drug discovery based on the data it actually

  17. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  18. Use of microinterrupts to provide an instrument oriented input/output structure

    International Nuclear Information System (INIS)

    Zaky, S.G.

    1981-01-01

    This paper describes the design of a bit-slice based computer, which has been developed for use in data acquisition and control applications. The main design goals have been to provide fast response to external events, and sufficient processing capability to perform data reduction in real time. The initial application of this computer has been in airborne, geophysical surveying, where such instruments as Gamma-ray spectrometers, magnetometers and navigation equipment are involved. In order to meet the response requirement mentioned above, a microinterrupt facility has been incorporated. Microinterrupts are serviced in microcodes routines which can be initiated within a maximum of two microinstruction cycle times from an external event. This facility makes it possible to implement powerful input/output control functions without the need for complex and specialized hardware interfaces for each instrument. (orig.)

  19. Spatiotemporal modeling of ozone levels in Quebec (Canada): a comparison of kriging, land-use regression (LUR), and combined Bayesian maximum entropy-LUR approaches.

    Science.gov (United States)

    Adam-Poupart, Ariane; Brand, Allan; Fournier, Michel; Jerrett, Michael; Smargiassi, Audrey

    2014-09-01

    Ambient air ozone (O3) is a pulmonary irritant that has been associated with respiratory health effects including increased lung inflammation and permeability, airway hyperreactivity, respiratory symptoms, and decreased lung function. Estimation of O3 exposure is a complex task because the pollutant exhibits complex spatiotemporal patterns. To refine the quality of exposure estimation, various spatiotemporal methods have been developed worldwide. We sought to compare the accuracy of three spatiotemporal models to predict summer ground-level O3 in Quebec, Canada. We developed a land-use mixed-effects regression (LUR) model based on readily available data (air quality and meteorological monitoring data, road networks information, latitude), a Bayesian maximum entropy (BME) model incorporating both O3 monitoring station data and the land-use mixed model outputs (BME-LUR), and a kriging method model based only on available O3 monitoring station data (BME kriging). We performed leave-one-station-out cross-validation and visually assessed the predictive capability of each model by examining the mean temporal and spatial distributions of the average estimated errors. The BME-LUR was the best predictive model (R2 = 0.653) with the lowest root mean-square error (RMSE ;7.06 ppb), followed by the LUR model (R2 = 0.466, RMSE = 8.747) and the BME kriging model (R2 = 0.414, RMSE = 9.164). Our findings suggest that errors of estimation in the interpolation of O3 concentrations with BME can be greatly reduced by incorporating outputs from a LUR model developed with readily available data.

  20. The effectiveness of a high output/short duration radiofrequency current application technique in segmental pulmonary vein isolation for atrial fibrillation

    DEFF Research Database (Denmark)

    Nilsson, Brian; Chen, Xu; Pehrson, Steen

    2006-01-01

    groups. In the conventional group (Group 1, 45 patients), the power output was limited to 30 W with a target temperature of 50 degrees C and an RF preset duration of 120 s. In the novel group (Group 2, 45 patients), the maximum power output was preset to 45 W, with a target temperature of 55 degrees C......AIMS: Segmental pulmonary vein (PV) isolation by radiofrequency (RF) catheter ablation has become a curative therapy for atrial fibrillation (AF). However, the long procedure time limits the wide application of this procedure. The aim of the current study was to compare a novel ablation technique...... and duration of 20 s. In Group 2, a significant reduction in the PV isolation time (127+/-57 vs. 94+/-33 min, P

  1. Using iMCFA to Perform the CFA, Multilevel CFA, and Maximum Model for Analyzing Complex Survey Data.

    Science.gov (United States)

    Wu, Jiun-Yu; Lee, Yuan-Hsuan; Lin, John J H

    2018-01-01

    To construct CFA, MCFA, and maximum MCFA with LISREL v.8 and below, we provide iMCFA (integrated Multilevel Confirmatory Analysis) to examine the potential multilevel factorial structure in the complex survey data. Modeling multilevel structure for complex survey data is complicated because building a multilevel model is not an infallible statistical strategy unless the hypothesized model is close to the real data structure. Methodologists have suggested using different modeling techniques to investigate potential multilevel structure of survey data. Using iMCFA, researchers can visually set the between- and within-level factorial structure to fit MCFA, CFA and/or MAX MCFA models for complex survey data. iMCFA can then yield between- and within-level variance-covariance matrices, calculate intraclass correlations, perform the analyses and generate the outputs for respective models. The summary of the analytical outputs from LISREL is gathered and tabulated for further model comparison and interpretation. iMCFA also provides LISREL syntax of different models for researchers' future use. An empirical and a simulated multilevel dataset with complex and simple structures in the within or between level was used to illustrate the usability and the effectiveness of the iMCFA procedure on analyzing complex survey data. The analytic results of iMCFA using Muthen's limited information estimator were compared with those of Mplus using Full Information Maximum Likelihood regarding the effectiveness of different estimation methods.

  2. Stationary average consensus protocol for a class of heterogeneous high-order multi-agent systems with application for aircraft

    Science.gov (United States)

    Rezaei, Mohammad Hadi; Menhaj, Mohammad Bagher

    2018-01-01

    This paper investigates the stationary average consensus problem for a class of heterogeneous-order multi-agent systems. The goal is to bring the positions of agents to the average of their initial positions while letting the other states converge to zero. To this end, three different consensus protocols are proposed. First, based on the auxiliary variables information among the agents under switching directed networks and state-feedback control, a protocol is proposed whereby all the agents achieve stationary average consensus. In the second and third protocols, by resorting to only measurements of relative positions of neighbouring agents under fixed balanced directed networks, two control frameworks are presented with two strategies based on state-feedback and output-feedback control. Finally, simulation results are given to illustrate the effectiveness of the proposed protocols.

  3. Electron emission of cathode holder of vacuum diode of an intense electron-beam accelerator and its effect on the output voltage

    Directory of Open Access Journals (Sweden)

    Xin-Bing Cheng

    2011-04-01

    Full Text Available The vacuum diode which is used to generate relativistic electron beams is one of the most important parts of a pulsed-power modulator. In this paper, the electron emission of cathode holder of a vacuum diode and its effect on the output voltage is investigated by experiments on an intense electron-beam accelerator with 180 ns full width at half maximum and 200–500 kV output voltage. First, the field emission is analyzed and the electric field of the vacuum chamber is calculated. Then, the flatness of the output voltage is discussed before and after adding an insulation plate when a water load is used. It is found that the electron emission at the edges of the cathode holder is the main reason to cause the change of the flatness. Last, a piece of polyester film is used as a target to further show the electron emission of the cathode holder. This analysis shows that decreasing the electron emission of the cathode holder in such a pulse power modulator could be a good way to improve the quality of the output voltage.

  4. Maximum Power Point Tracking for Cascaded PV-Converter Modules Using Two-Stage Particle Swarm Optimization.

    Science.gov (United States)

    Mao, Mingxuan; Duan, Qichang; Zhang, Li; Chen, Hao; Hu, Bei; Duan, Pan

    2017-08-24

    The paper presents a novel two-stage particle swarm optimization (PSO) for the maximum power point tracking (MPPT) control of a PV system consisting of cascaded PV-converter modules, under partial shading conditions (PSCs). In this scheme, the grouping method of the shuffled frog leaping algorithm (SFLA) is incorporated with the basic PSO algorithm, ensuring fast and accurate searching of the global extremum. An adaptive speed factor is also introduced to improve its convergence speed. A PWM algorithm enabling permuted switching of the PV sources is applied. The method enables this PV system to achieve the maximum power generation for any number of PV and converter modules. Simulation studies of the proposed MPPT scheme are performed on a system having two chained PV buck-converter modules and a dc-ac H-bridge connected at its terminals for supplying an AC load. The results show that this type of PV system allows each module to achieve the maximum power generation according its illumination level without affecting the others, and the proposed new control method gives significantly higher power output compared with the conventional P&O and PSO methods.

  5. A coupled piezoelectric–electromagnetic energy harvesting technique for achieving increased power output through damping matching

    International Nuclear Information System (INIS)

    Challa, Vinod R; Prasad, M G; Fisher, Frank T

    2009-01-01

    Vibration energy harvesting is being pursued as a means to power wireless sensors and ultra-low power autonomous devices. From a design standpoint, matching the electrical damping induced by the energy harvesting mechanism to the mechanical damping in the system is necessary for maximum efficiency. In this work two independent energy harvesting techniques are coupled to provide higher electrical damping within the system. Here the coupled energy harvesting device consists of a primary piezoelectric energy harvesting device to which an electromagnetic component is added to better match the total electrical damping to the mechanical damping in the system. The first coupled device has a resonance frequency of 21.6 Hz and generates a peak power output of ∼332 µW, compared to 257 and 244 µW obtained from the optimized, stand-alone piezoelectric and electromagnetic energy harvesting devices, respectively, resulting in a 30% increase in power output. A theoretical model has been developed which closely agrees with the experimental results. A second coupled device, which utilizes the d 33 piezoelectric mode, shows a 65% increase in power output in comparison to the corresponding stand-alone, single harvesting mode devices. This work illustrates the design considerations and limitations that one must consider to enhance device performance through the coupling of multiple harvesting mechanisms within a single energy harvesting device

  6. Input/Output linearizing control of a nuclear reactor

    International Nuclear Information System (INIS)

    Perez C, V.

    1994-01-01

    The feedback linearization technique is an approach to nonlinear control design. The basic idea is to transform, by means of algebraic methods, the dynamics of a nonlinear control system into a full or partial linear system. As a result of this linearization process, the well known basic linear control techniques can be used to obtain some desired dynamic characteristics. When full linearization is achieved, the method is referred to as input-state linearization, whereas when partial linearization is achieved, the method is referred to as input-output linearization. We will deal with the latter. By means of input-output linearization, the dynamics of a nonlinear system can be decomposed into an external part (input-output), and an internal part (unobservable). Since the external part consists of a linear relationship among the output of the plant and the auxiliary control input mentioned above, it is easy to design such an auxiliary control input so that we get the output to behave in a predetermined way. Since the internal dynamics of the system is known, we can check its dynamics behavior on order of to ensure that the internal states are bounded. The linearization method described here can be applied to systems with one-input/one-output, as well as to systems with multiple-inputs/multiple-outputs. Typical control problems such as stabilization and reference path tracking can be solved using this technique. In this work, the input/output linearization theory is presented, as well as the problem of getting the output variable to track some desired trayectories. Further, the design of an input/output control system applied to the nonlinear model of a research nuclear reactor is included, along with the results obtained by computer simulation. (Author)

  7. Optimized Adaptive Perturb and Observe Maximum Power Point Tracking Control for Photovoltaic Generation

    Directory of Open Access Journals (Sweden)

    Luigi Piegari

    2015-04-01

    Full Text Available The power extracted from PV arrays is usually maximized using maximum power point tracking algorithms. One of the most widely used techniques is the perturb & observe algorithm, which periodically perturbs the operating point of the PV array, sometime with an adaptive perturbation step, and compares the PV power before and after the perturbation. This paper analyses the most suitable perturbation step to optimize maximum power point tracking performance and suggests a design criterion to select the parameters of the controller. Using this proposed adaptive step, the MPPT perturb & observe algorithm achieves an excellent dynamic response by adapting the perturbation step to the actual operating conditions of the PV array. The proposed algorithm has been validated and tested in a laboratory using a dual input inductor push-pull converter. This particular converter topology is an efficient interface to boost the low voltage of PV arrays and effectively control the power flow when input or output voltages are variable. The experimental results have proved the superiority of the proposed algorithm in comparison of traditional perturb & observe and incremental conductance techniques.

  8. A hybrid method for forecasting the energy output of photovoltaic systems

    International Nuclear Information System (INIS)

    Ramsami, Pamela; Oree, Vishwamitra

    2015-01-01

    Highlights: • We propose a novel hybrid technique for predicting the daily PV energy output. • Multiple linear regression, FFNN and GRNN artificial neural networks are used. • Stepwise regression is used to select the most relevant meteorological parameters. • SR-FFNN reduces the average dispersion and overall bias in prediction errors. • Accuracy metrics of hybrid models are better than those of single-stage models. - Abstract: The intermittent nature of solar energy poses many challenges to renewable energy system operators in terms of operational planning and scheduling. Predicting the output of photovoltaic systems is therefore essential for managing the operation and assessing the economic performance of power systems. This paper presents a new technique for forecasting the 24-h ahead stochastic energy output of photovoltaic systems based on the daily weather forecasts. A comparison of the performances of the hybrid technique with conventional linear regression and artificial neural network models has also been reported. Initially, three single-stage models were designed, namely the generalized regression neural network, feedforward neural network and multiple linear regression. Subsequently, a hybrid-modeling approach was adopted by applying stepwise regression to select input variables of greater importance. These variables were then fed to the single-stage models resulting in three hybrid models. They were then validated by comparing the forecasts of the models with measured dataset from an operational photovoltaic system. The accuracy of the each model was evaluated based on the correlation coefficient, mean absolute error, mean bias error and root mean square error values. Simulation results revealed that the hybrid models perform better than their corresponding single-stage models. Stepwise regression-feedforward neural network hybrid model outperformed the other models with root mean square error, mean absolute error, mean bias error and

  9. Are output measurements always necessary after CT tube replacement?

    Directory of Open Access Journals (Sweden)

    Paul J Stauduhar

    2014-03-01

    Full Text Available Purpose: TX regulations and the ACR require that CT radiation output be measured within 30 days of major service. The most common major service is tube replacement. We hypothesized that historical QC data could be used instead to determine if output measurements are necessary, reducing the need for costly output measurements.Methods: We reviewed 66 records of tube replacements to determine with what frequency output falls outside specifications. We also conducted an experiment to verify that clinically significant output changes could be identified by comparing image noise in historical QC data with the same data after tube replacement. We used 30 days of historical QC data to establish a baseline noise level and 95% confidence interval (CI for individual noise measurements. To simulate output changes, we acquired phantom images with our QC protocol while manually changing output (mA. We acquired 10 images using the baseline output and 10 images at each different “output”. We evaluated individual images and subsets of images at each “output” to determine if the system was within the manufacturer’s specifications.Results: None of the 66 tube replacements resulted in an output change that exceeded specifications. Analysis of 30 days of historic QC data for our experimental system indicated a mean noise of 5.4 HU with 95% CI of 5.1 ‒ 5.7 HU. When using the mean noise of 10 images acquired at each of the varying outputs, we were able to identify, with 100% accuracy, images acquired at outputs outside manufacturer’s specifications.Conclusion: The results of our review of historical tube replacement data indicated the likelihood of output falling outside manufacturer’s specifications is low. Considering this, it is likely that by using QC data from programs required by regulation and the ACR physicists can reliably verify radiation output stability remotely instead of making physical measurements.--------------------Cite this article

  10. Maximum one-shot dissipated work from Rényi divergences

    Science.gov (United States)

    Yunger Halpern, Nicole; Garner, Andrew J. P.; Dahlsten, Oscar C. O.; Vedral, Vlatko

    2018-05-01

    Thermodynamics describes large-scale, slowly evolving systems. Two modern approaches generalize thermodynamics: fluctuation theorems, which concern finite-time nonequilibrium processes, and one-shot statistical mechanics, which concerns small scales and finite numbers of trials. Combining these approaches, we calculate a one-shot analog of the average dissipated work defined in fluctuation contexts: the cost of performing a protocol in finite time instead of quasistatically. The average dissipated work has been shown to be proportional to a relative entropy between phase-space densities, to a relative entropy between quantum states, and to a relative entropy between probability distributions over possible values of work. We derive one-shot analogs of all three equations, demonstrating that the order-infinity Rényi divergence is proportional to the maximum possible dissipated work in each case. These one-shot analogs of fluctuation-theorem results contribute to the unification of these two toolkits for small-scale, nonequilibrium statistical physics.

  11. Uninterrupted thermoelectric energy harvesting using temperature-sensor-based maximum power point tracking system

    International Nuclear Information System (INIS)

    Park, Jae-Do; Lee, Hohyun; Bond, Matthew

    2014-01-01

    Highlights: • Feedforward MPPT scheme for uninterrupted TEG energy harvesting is suggested. • Temperature sensors are used to avoid current measurement or source disconnection. • MPP voltage reference is generated based on OCV vs. temperature differential model. • Optimal operating condition is maintained using hysteresis controller. • Any type of power converter can be used in the proposed scheme. - Abstract: In this paper, a thermoelectric generator (TEG) energy harvesting system with a temperature-sensor-based maximum power point tracking (MPPT) method is presented. Conventional MPPT algorithms for photovoltaic cells may not be suitable for thermoelectric power generation because a significant amount of time is required for TEG systems to reach a steady state. Moreover, complexity and additional power consumption in conventional circuits and periodic disconnection of power source are not desirable for low-power energy harvesting applications. The proposed system can track the varying maximum power point (MPP) with a simple and inexpensive temperature-sensor-based circuit without instantaneous power measurement or TEG disconnection. This system uses TEG’s open circuit voltage (OCV) characteristic with respect to temperature gradient to generate a proper reference voltage signal, i.e., half of the TEG’s OCV. The power converter controller maintains the TEG output voltage at the reference level so that the maximum power can be extracted for the given temperature condition. This feedforward MPPT scheme is inherently stable and can be implemented without any complex microcontroller circuit. The proposed system has been validated analytically and experimentally, and shows a maximum power tracking error of 1.15%

  12. Influence of Special Weather on Output of PV System

    Science.gov (United States)

    Zhang, Zele

    2018-01-01

    The output of PV system is affected by different environmental factors, therefore, it is important to study the output of PV system under different environmental conditions. Through collecting data on the spot, collecting the output of photovoltaic panels under special weather conditions, and comparing the collected data, the output characteristics of the photovoltaic panels under different weather conditions are obtained. The influence of weather factors such as temperature, humidity and irradiance on the output of photovoltaic panels was investigated.

  13. Evaluation of two water-equivalent phantom materials for output calibration of photon and electron beams

    International Nuclear Information System (INIS)

    Liu Lizhong; Prasad, Satish C.; Bassano, Daniel A.

    2003-01-01

    Two commercially available water-equivalent solid phantom materials were evaluated for output calibration in both photon (6-15 MV) and electron (6-20 MeV) beams. The solid water 457 and virtual water materials have the same chemical composition but differ in manufacturing process and density. A Farmer-type ionization chamber was used for measuring the output of the photon beams at 5- and 10-cm depth and electron beams at maximum buildup depth in the solid phantoms and in natural water. The water-equivalency correction factor for the solid materials is defined as the ratio of the chamber reading in natural water to that in the solid at the same linear depth. For photon beams, the correction factor was found to be independent of depth and was 0.987 and 0.993 for 6- and 15-MV beams, respectively, for solid water. For virtual water, the corresponding correction factors were 0.993 and 0.998 for 6- and 15-MV beams, respectively. For electron beams, the correction factors ranged from 1.013 to 1.007 for energies of 6 to 20 MeV for both solid materials. This indicated that the water-equivalency of these materials is within ± 1.3%, making them suitable substitutes for natural water in both photon and electron beam output measurements over a wide energy range. These correction factors are slightly larger than the manufacturers' advertised values (± 1.0% for solid water and ± 0.5% for virtual water). We suggest that these corrections are large enough in most cases and should be applied in the calculation of beam outputs

  14. The size and spatial distribution of microchannel plate output electron clouds

    International Nuclear Information System (INIS)

    Lapington, J.S.; Edgar, M.L.

    1989-01-01

    An experimental technique for measuring the spatial distribution of the output charge cloud from a microchannel plate (MCP), using a planar, charge-division-type anode is discussed. The anode simultaneously measures, for each charge cloud, both the position of the charge centroid and the fractional charge falling to one side of the split in the pattern. The measurements from several thousand events have been combined to calculate the average spatial distribution of the electron cloud and the dominant factors influencing the charge cloud distribution have been found to be the MCP gain and the MCP-anode accelerating field and geometry. Experimental research on the two dominant factors with respect to ranges of distribution is presented. 10 refs

  15. Dense Output for Strong Stability Preserving Runge–Kutta Methods

    KAUST Repository

    Ketcheson, David I.

    2016-12-10

    We investigate dense output formulae (also known as continuous extensions) for strong stability preserving (SSP) Runge–Kutta methods. We require that the dense output formula also possess the SSP property, ideally under the same step-size restriction as the method itself. A general recipe for first-order SSP dense output formulae for SSP methods is given, and second-order dense output formulae for several optimal SSP methods are developed. It is shown that SSP dense output formulae of order three and higher do not exist, and that in any method possessing a second-order SSP dense output, the coefficient matrix A has a zero row.

  16. Observability of linear systems with saturated outputs

    NARCIS (Netherlands)

    Koplon, R.; Sontag, E.D.; Hautus, M.L.J.

    1994-01-01

    We present necessary and sufficient conditions for observability of the class of output-saturated systems. These are linear systems whose output passes through a saturation function before it can be measured.

  17. Sugar beet for bioethanol production: An approach based on environmental agricultural outputs

    International Nuclear Information System (INIS)

    Salazar-Ordóñez, Melania; Pérez-Hernández, Pedro P.; Martín-Lozano, José M.

    2013-01-01

    The EU imports both bioethanol and the raw material needed to produce it. Thirty percent of bioethanol is produced from sugar beets in the EU. However, sugar beet cultivated area and yields have fallen due to the 2006 sugar regime reform. Given the potential uncertainty about the future for sugar beet farmers, biofuels may represent an alternative market. This paper analyses potential contribution to the efficiency, in terms of environmental output, of the sugar beet crop both when production is oriented toward bioethanol and regarding the use of input. An empirical application is performed in Spain by Data Envelopment Analysis (DEA). The results show that 4% of farms have full technical efficiency, while the rest have an average efficiency of 55.9%. The figures show that inputs can be reduced over 40%, and also show the low average level of input-use efficiency. In addition, it cannot be said that there is a relationship between efficiency and farm scale. The consideration of aspects such as the environmental advantages of using sugar beet production for bioethanol can open new lines of action to support this crop in the EU. In addition, boosting sugar beet production may reduce potential dependency on importation. - Highlights: ► Analysing environmental outputs from agricultural input use and production orientation to bioethanol. ► DEA is applied to model farms’ efficiency in GHG emission and nitrous oxides emissions. ► A very low level of efficiency is found in sugar beet farms. ► Efficiency increase should be supported to reduce fertilizers and pesticides. ► Environmental advantages of addressing sugar beet to bioethanol open new lines to support crops

  18. Vegetable output and cost savings of community gardens in San Jose, California.

    Science.gov (United States)

    Algert, Susan J; Baameur, Aziz; Renvall, Marian J

    2014-07-01

    Urban dwellers across the United States increasingly access a variety of fresh vegetables through participation in neighborhood-level community gardens. Here we document vegetable output and cost savings of community gardens in the city of San Jose, CA, to better understand the capacity of community gardens to affect food affordability in an urban setting. A convenience sample of 83 community gardeners in San Jose completed a background survey during spring and summer 2012. On average, gardeners were aged 57 years and had a monthly income of $4,900; 25% had completed college. A representative subset of 10 gardeners was recruited to weigh vegetable output of their plots using portable electronic scales at three separate garden sites. Accuracy of each portable scale was verified by comparing the weight of a sample vegetable to weights obtained using a lab scale precise to 0.2 oz. Garden yields and cost savings were tabulated overall for each plot. Results indicate that community garden practices are more similar to biointensive high-production farming, producing 0.75 lb vegetables/sq ft, rather than conventional agricultural practices, producing 0.60 lb/sq ft. Gardens produced on average 2.55 lb/plant and saved $435 per plot for the season. Results indicate that cost savings are greatest if vertical high value crops such as tomatoes and peppers are grown in community gardens, although yields depend on growing conditions, gardener's skill, availability of water, and other factors. Future research is needed to document cost savings and yields for specific crops grown in community gardens. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  19. Output gap uncertainty and real-time monetary policy

    Directory of Open Access Journals (Sweden)

    Francesco Grigoli

    2015-12-01

    Full Text Available Output gap estimates are subject to a wide range of uncertainty owing principally to the difficulty in distinguishing between cycle and trend in real time. We show that country desks tend to overestimate economic slack, especially during recessions, and that uncertainty in initial output gap estimates persists several years. Only a small share of output gap revisions is predictable based on output dynamics, data quality, and policy frameworks. We also show that for a group of Latin American inflation targeters the prescriptions from monetary policy rules are subject to large changes due to revised output gap estimates. These explain a sizable proportion of the deviation of inflation from target, suggesting this information is not accounted for in real-time policy decisions.

  20. Peripheral vasodilatation determines cardiac output in exercising humans

    DEFF Research Database (Denmark)

    Bada, A A; Svendsen, J H; Secher, N H

    2012-01-01

    In dogs, manipulation of heart rate has no effect on the exercise-induced increase in cardiac output. Whether these findings apply to humans remain uncertain, because of the large differences in cardiovascular anatomy and regulation. To investigate the role of heart rate and peripheral...... arterial ATP infusion at rest. Exercise and ATP infusion increased cardiac output, leg blood flow and vascular conductance (P heart rate by up to 54 beats min(−1), cardiac output did not change in any of the three...... demonstrate that the elevated cardiac output during steady-state exercise is regulated by the increase in skeletal muscle blood flow and venous return to the heart, whereas the increase in heart rate appears to be secondary to the regulation of cardiac output....

  1. SU-E-T-469: A Practical Approach for the Determination of Small Field Output Factors Using Published Monte Carlo Derived Correction Factors

    International Nuclear Information System (INIS)

    Calderon, E; Siergiej, D

    2014-01-01

    Purpose: Output factor determination for small fields (less than 20 mm) presents significant challenges due to ion chamber volume averaging and diode over-response. Measured output factor values between detectors are known to have large deviations as field sizes are decreased. No set standard to resolve this difference in measurement exists. We observed differences between measured output factors of up to 14% using two different detectors. Published Monte Carlo derived correction factors were used to address this challenge and decrease the output factor deviation between detectors. Methods: Output factors for Elekta's linac-based stereotactic cone system were measured using the EDGE detector (Sun Nuclear) and the A16 ion chamber (Standard Imaging). Measurements conditions were 100 cm SSD (source to surface distance) and 1.5 cm depth. Output factors were first normalized to a 10.4 cm × 10.4 cm field size using a daisy-chaining technique to minimize the dependence of field size on detector response. An equation expressing the relation between published Monte Carlo correction factors as a function of field size for each detector was derived. The measured output factors were then multiplied by the calculated correction factors. EBT3 gafchromic film dosimetry was used to independently validate the corrected output factors. Results: Without correction, the deviation in output factors between the EDGE and A16 detectors ranged from 1.3 to 14.8%, depending on cone size. After applying the calculated correction factors, this deviation fell to 0 to 3.4%. Output factors determined with film agree within 3.5% of the corrected output factors. Conclusion: We present a practical approach to applying published Monte Carlo derived correction factors to measured small field output factors for the EDGE and A16 detectors. Using this method, we were able to decrease the percent deviation between both detectors from 14.8% to 3.4% agreement

  2. The Association Between Urine Output, Creatinine Elevation, and Death.

    Science.gov (United States)

    Engoren, Milo; Maile, Michael D; Heung, Michael; Jewell, Elizabeth S; Vahabzadeh, Christie; Haft, Jonathan W; Kheterpal, Sachin

    2017-04-01

    Acute kidney injury can be defined by a fall in urine output, and urine output criteria may be more sensitive in identifying acute kidney injury than traditional serum creatinine criteria. However, as pointed out in the Kidney Disease Improving Global Outcome guidelines, the association of urine output with subsequent creatinine elevations and death is poorly characterized. The purpose of this study was to determine what degrees of reduced urine output are associated with subsequent creatinine elevation and death. This was a retrospective cohort study of adult patients (age ≥18 years) cared for in a cardiovascular intensive care unit after undergoing cardiac operations in a tertiary care university medical center. All adult patients who underwent cardiac operations and were not receiving dialysis preoperatively were studied. The development of acute kidney injury was defined as an increase in creatinine of more than 0.3 mg/dL or by more than 50% above baseline by postoperative day 3. Acute kidney injury developed in 1,061 of 4,195 patients (25%). Urine output had moderate discrimination in predicting subsequent acute kidney injury (C statistic = .637 ± .054). Lower urine output and longer duration of low urine output were associated with greater odds of developing acute kidney injury and death. We found that there is similar accuracy in using urine output corrected for actual, ideal, or adjusted weight to discriminate future acute kidney injury by creatinine elevation and recommend using actual weight for its simplicity. We also found that low urine output is associated with subsequent acute kidney injury and that the association is greater for lower urine output and for low urine output of longer durations. Low urine output (creatinine elevation, is independently associated with mortality. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Efficient Photovoltaic System Maximum Power Point Tracking Using a New Technique

    Directory of Open Access Journals (Sweden)

    Mehdi Seyedmahmoudian

    2016-03-01

    Full Text Available Partial shading is an unavoidable condition which significantly reduces the efficiency and stability of a photovoltaic (PV system. When partial shading occurs the system has multiple-peak output power characteristics. In order to track the global maximum power point (GMPP within an appropriate period a reliable technique is required. Conventional techniques such as hill climbing and perturbation and observation (P&O are inadequate in tracking the GMPP subject to this condition resulting in a dramatic reduction in the efficiency of the PV system. Recent artificial intelligence methods have been proposed, however they have a higher computational cost, slower processing time and increased oscillations which results in further instability at the output of the PV system. This paper proposes a fast and efficient technique based on Radial Movement Optimization (RMO for detecting the GMPP under partial shading conditions. The paper begins with a brief description of the behavior of PV systems under partial shading conditions followed by the introduction of the new RMO-based technique for GMPP tracking. Finally, results are presented to demonstration the performance of the proposed technique under different partial shading conditions. The results are compared with those of the PSO method, one of the most widely used methods in the literature. Four factors, namely convergence speed, efficiency (power loss reduction, stability (oscillation reduction and computational cost, are considered in the comparison with the PSO technique.

  4. Criticality evaluation of BWR MOX fuel transport packages using average Pu content

    International Nuclear Information System (INIS)

    Mattera, C.; Martinotti, B.

    2004-01-01

    Currently in France, criticality studies in transport configurations for Boiling Water Reactor Mixed Oxide fuel assemblies are based on conservative hypothesis assuming that all rods (Mixed Oxide (Uranium and Plutonium), Uranium Oxide, Uranium and Gadolinium Oxide rods) are Mixed Oxide rods with the same Plutonium-content, corresponding to the maximum value. In that way, the real heterogeneous mapping of the assembly is masked and covered by a homogeneous Plutonium-content assembly, enriched at the maximum value. As this calculation hypothesis is extremely conservative, COGEMA LOGISTICS has studied a new calculation method based on the average Plutonium-content in the criticality studies. The use of the average Plutonium-content instead of the real Plutonium-content profiles provides a highest reactivity value that makes it globally conservative. This method can be applied for all Boiling Water Reactor Mixed Oxide complete fuel assemblies of type 8 x 8, 9 x 9 and 10 x 10 which Plutonium-content in mass weight does not exceed 15%; it provides advantages which are discussed in our approach. With this new method, for the same package reactivity, the Pu-content allowed in the package design approval can be higher. The COGEMA LOGISTICS' new method allows, at the design stage, to optimise the basket, materials or geometry for higher payload, keeping the same reactivity

  5. Hydrogen preheating through waste heat recovery of an open-cathode PEM fuel cell leading to power output improvement

    International Nuclear Information System (INIS)

    Mohamed, W.A.N.W.; Kamikl, M. Haziq M.

    2016-01-01

    Highlights: • A study on the effect of hydrogen preheating using waste heat for low temperature PEM fuel cells. • Theoretical, experimental and analytical framework was established. • The maximum electrical power output increases by 8–10% under specific operating conditions. • Open loop hydrogen supply gives a better performance than closed loop. • The waste heat utilization is less than 10% due to heat capacity limitations. - Abstract: The electrochemical reaction kinetics in a Polymer Electrolyte Membrane (PEM) fuel cell is highly influenced by the reactants supply pressures and electrode temperatures. For an open cathode PEM fuel cell stack, the power output is constrained due to the use of air simultaneously as reactant and coolant. Optimal stack operation temperatures are not achieved especially at low to medium power outputs. Based on the ideal gas law, higher reactant temperatures would lead to higher pressures and subsequently improve the reaction kinetics. The hydrogen supply temperature and its pressure can be increased by preheating; thus, slightly offsetting the limitation of low operating stack temperatures. The exit air stream offers an internal source of waste heat for the hydrogen preheating purpose. In this study, a PEM open-cathode fuel cell was used to experimentally evaluate the performance of hydrogen preheating based on two waste heat recovery approaches: (1) open-loop and (2) closed loop hydrogen flow. The stack waste heat was channelled into a heat exchanger to preheat the hydrogen line before it is being supplied (open loop) or resupplied (closed loop) into the stack. At a constant 0.3 bar hydrogen supply pressure, the preheating increases the hydrogen temperature in the range of 2–13 °C which was dependant on the stack power output and cathode air flow rates. The achievable maximum stack power was increased by 8% for the closed loop and 10% for the open loop. Due to the small hydrogen flow rates, the waste heat utilization

  6. Geographic trends of scientific output and citation practices in psychiatry.

    Science.gov (United States)

    Igoumenou, Artemis; Ebmeier, Klaus; Roberts, Nia; Fazel, Seena

    2014-12-06

    Measures of research productivity are increasingly used to determine how research should be evaluated and funding decisions made. In psychiatry, citation patterns within and between countries are not known, and whether these differ by choice of citation metric. In this study, we examined publication characteristics and citation practices in articles published in 50 Web of Science indexed psychiatric and relevant clinical neurosciences journals, between January 2004 and December 2009 comprising 51,072 records that produced 375,962 citations. We compared citation patterns, including self-citations, between countries using standard x(2) tests. We found that most publications came from the USA, with Germany being second and UK third in productivity. USA articles received most citations and the highest citation rate with an average 11.5 citations per article. The UK received the second highest absolute number of citations, but came fourth by citation rate (9.7 citations/article), after the Netherlands (11.4 citations/article) and Canada (9.8 citations/article). Within the USA, Harvard University published most articles and these articles were the most cited, on average 20.0 citations per paper. In Europe, UK institutions published and were cited most often. The Institute of Psychiatry/Kings College London was the leading institution in terms of number of published records and overall citations, while Oxford University had the highest citation rate (18.5 citations/record). There were no differences between the self-citation practices of American and European researchers. Articles that examined some aspect of treatment in psychiatry were the most published. In terms of diagnosis, papers about schizophrenia-spectrum disorders were the most published and the most cited. We found large differences between and within countries in terms of their research productivity in psychiatry and clinical neuroscience. In addition, the ranking of countries and institutions differed widely

  7. W5″ Test: A simple method for measuring mean power output in the bench press exercise.

    Science.gov (United States)

    Tous-Fajardo, Julio; Moras, Gerard; Rodríguez-Jiménez, Sergio; Gonzalo-Skok, Oliver; Busquets, Albert; Mujika, Iñigo

    2016-11-01

    The aims of the present study were to assess the validity and reliability of a novel simple test [Five Seconds Power Test (W5″ Test)] for estimating the mean power output during the bench press exercise at different loads, and its sensitivity to detect training-induced changes. Thirty trained young men completed as many repetitions as possible in a time of ≈5 s at 25%, 45%, 65% and 85% of one-repetition maximum (1RM) in two test sessions separated by four days. The number of repetitions, linear displacement of the bar and time needed to complete the test were recorded by two independent testers, and a linear encoder was used as the criterion measure. For each load, the mean power output was calculated in the W5″ Test as mechanical work per time unit and compared with that obtained from the linear encoder. Subsequently, 20 additional subjects (10 training group vs. 10 control group) were assessed before and after completing a seven-week training programme designed to improve maximal power. Results showed that both assessment methods correlated highly in estimating mean power output at different loads (r range: 0.86-0.94; p bench press exercise in subjects who have previous resistance training experience.

  8. Extracting Credible Dependencies for Averaged One-Dependence Estimator Analysis

    Directory of Open Access Journals (Sweden)

    LiMin Wang

    2014-01-01

    Full Text Available Of the numerous proposals to improve the accuracy of naive Bayes (NB by weakening the conditional independence assumption, averaged one-dependence estimator (AODE demonstrates remarkable zero-one loss performance. However, indiscriminate superparent attributes will bring both considerable computational cost and negative effect on classification accuracy. In this paper, to extract the most credible dependencies we present a new type of seminaive Bayesian operation, which selects superparent attributes by building maximum weighted spanning tree and removes highly correlated children attributes by functional dependency and canonical cover analysis. Our extensive experimental comparison on UCI data sets shows that this operation efficiently identifies possible superparent attributes at training time and eliminates redundant children attributes at classification time.

  9. Influence of directionality and maximal power output on speech understanding with bone anchored hearing implants in single sided deafness

    OpenAIRE

    Krempaska, Silvia; Koval, Juraj; Schmid, Christoph; Pfiffner, Flurin; Kurz, Anja; Kompis, Martin

    2014-01-01

    Bone-anchored hearing implants (BAHI) are routinely used to alleviate the effects of the acoustic head shadow in single-sided sensorineural deafness (SSD). In this study, the influence of the directional microphone setting and the maximum power output of the BAHI sound processor on speech understanding in noise in a laboratory setting were investigated. Eight adult BAHI users with SSD participated in this pilot study. Speech understanding in noise was measured using a new Slovak speech-in-noi...

  10. Evaluation of the annual electric energy output of an a-Si:H solar cellin various regions of the CIS countries

    International Nuclear Information System (INIS)

    Kryuchenko, Yu.V.; Sachenko, A.V.; Bobyl, A.V.; Kostylyov, V.P.; Sokolovskyi, I.O.; Terukov, E.I.; Tokmoldin, N.; Tokmoldin, S. Zh.; Smirnov, A.V.

    2014-01-01

    We have calculated annual (i.e., for each day of the year) daytime dependences of the electric power output per unit area of an a-Si:H solar cell (SC) at latitudes 45°N, 50°N, 55°N, 60°N and at certain geographical points of Russia, Kazakhstan, Ukraine and Belarus. The calculations were based on a rigorous theoretical model, which allows to determine photoconversion efficiency, optimal electric power output and other photovoltaic electrical characteristics at arbitrary angles of solar irradiance incidence on an a-Si:H-based SC. Parameters of the a-Si:H SC under consideration provide photoconversion efficiency of 10% at 12:00 noon on equinox day at the 45°N latitude despite small total thickness of 0.7 µm of the a-Si:H SC structure up to the rear contact. Normalization of the obtained results by maximal values enables one to infer respective time dependencies for other types of SCs. In combination with the data on average numbers of sunny days per year (or average annual sunshine hours) for certain geographical regions, this provides a way for understanding the feasibility of solar electricity generation in these regions. Based on this study, we identify regions of Russia, Kazakhstan and Ukraine, for which electricity generation exceeds the average values by over 30%. - Highlights: • We model solar power generation from an amorphous silicon solar cell at moderate latitudes from 45°N to 60°N. • We model solar power generation from an amorphous silicon solar cell as applied to Belarus, Kazakhstan, Russia and Ukraine. • The calculations are based on our rigorous model taking into account atmospheric conditions at a given location. • Annual time-dependency of power output and optimal values of solar energy generated at the various locations are determined

  11. Numerical and experimental research on pentagonal cross-section of the averaging Pitot tube

    Science.gov (United States)

    Zhang, Jili; Li, Wei; Liang, Ruobing; Zhao, Tianyi; Liu, Yacheng; Liu, Mingsheng

    2017-07-01

    Averaging Pitot tubes have been widely used in many fields because of their simple structure and stable performance. This paper introduces a new shape of the cross-section of an averaging Pitot tube. Firstly, the structure of the averaging Pitot tube and the distribution of pressure taps are given. Then, a mathematical model of the airflow around it is formulated. After that, a series of numerical simulations are carried out to optimize the geometry of the tube. The distribution of the streamline and pressures around the tube are given. To test its performance, a test platform was constructed in accordance with the relevant national standards and is described in this paper. Curves are provided, linking the values of flow coefficient with the values of Reynolds number. With a maximum deviation of only  ±3%, the results of the flow coefficient obtained from the numerical simulations were in agreement with those obtained from experimental methods. The proposed tube has a stable flow coefficient and favorable metrological characteristics.

  12. Residual gravimetric method to measure nebulizer output.

    Science.gov (United States)

    Vecellio None, Laurent; Grimbert, Daniel; Bordenave, Joelle; Benoit, Guy; Furet, Yves; Fauroux, Brigitte; Boissinot, Eric; De Monte, Michele; Lemarié, Etienne; Diot, Patrice

    2004-01-01

    The aim of this study was to assess a residual gravimetric method based on weighing dry filters to measure the aerosol output of nebulizers. This residual gravimetric method was compared to assay methods based on spectrophotometric measurement of terbutaline (Bricanyl, Astra Zeneca, France), high-performance liquid chromatography (HPLC) measurement of tobramycin (Tobi, Chiron, U.S.A.), and electrochemical measurements of NaF (as defined by the European standard). Two breath-enhanced jet nebulizers, one standard jet nebulizer, and one ultrasonic nebulizer were tested. Output produced by the residual gravimetric method was calculated by weighing the filters both before and after aerosol collection and by filter drying corrected by the proportion of drug contained in total solute mass. Output produced by the electrochemical, spectrophotometric, and HPLC methods was determined after assaying the drug extraction filter. The results demonstrated a strong correlation between the residual gravimetric method (x axis) and assay methods (y axis) in terms of drug mass output (y = 1.00 x -0.02, r(2) = 0.99, n = 27). We conclude that a residual gravimetric method based on dry filters, when validated for a particular agent, is an accurate way of measuring aerosol output.

  13. Input-output interactions and optimal monetary policy

    DEFF Research Database (Denmark)

    Petrella, Ivan; Santoro, Emiliano

    2011-01-01

    This paper deals with the implications of factor demand linkages for monetary policy design in a two-sector dynamic general equilibrium model. Part of the output of each sector serves as a production input in both sectors, in accordance with a realistic input–output structure. Strategic...... complementarities induced by factor demand linkages significantly alter the transmission of shocks and amplify the loss of social welfare under optimal monetary policy, compared to what is observed in standard two-sector models. The distinction between value added and gross output that naturally arises...... in this context is of key importance to explore the welfare properties of the model economy. A flexible inflation targeting regime is close to optimal only if the central bank balances inflation and value added variability. Otherwise, targeting gross output variability entails a substantial increase in the loss...

  14. Averaging models: parameters estimation with the R-Average procedure

    Directory of Open Access Journals (Sweden)

    S. Noventa

    2010-01-01

    Full Text Available The Functional Measurement approach, proposed within the theoretical framework of Information Integration Theory (Anderson, 1981, 1982, can be a useful multi-attribute analysis tool. Compared to the majority of statistical models, the averaging model can account for interaction effects without adding complexity. The R-Average method (Vidotto & Vicentini, 2007 can be used to estimate the parameters of these models. By the use of multiple information criteria in the model selection procedure, R-Average allows for the identification of the best subset of parameters that account for the data. After a review of the general method, we present an implementation of the procedure in the framework of R-project, followed by some experiments using a Monte Carlo method.

  15. Rice growing farmers efficiency measurement using a slack based interval DEA model with undesirable outputs

    Science.gov (United States)

    Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

    2017-11-01

    In recent years eco-efficiency which considers the effect of production process on environment in determining the efficiency of firms have gained traction and a lot of attention. Rice farming is one of such production processes which typically produces two types of outputs which are economic desirable as well as environmentally undesirable. In efficiency analysis, these undesirable outputs cannot be ignored and need to be included in the model to obtain the actual estimation of firm's efficiency. There are numerous approaches that have been used in data envelopment analysis (DEA) literature to account for undesirable outputs of which directional distance function (DDF) approach is the most widely used as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, slack based DDF DEA approaches considers the output shortfalls and input excess in determining efficiency. In situations when data uncertainty is present, the deterministic DEA model is not suitable to be used as the effects of uncertain data will not be considered. In this case, it has been found that interval data approach is suitable to account for data uncertainty as it is much simpler to model and need less information regarding the underlying data distribution and membership function. The proposed model uses an enhanced DEA model which is based on DDF approach and incorporates slack based measure to determine efficiency in the presence of undesirable factors and data uncertainty. Interval data approach was used to estimate the values of inputs, undesirable outputs and desirable outputs. Two separate slack based interval DEA models were constructed for optimistic and pessimistic scenarios. The developed model was used to determine rice farmers efficiency from Kepala Batas, Kedah. The obtained results were later compared to the results obtained using a deterministic DDF DEA model. The study found that 15 out of 30 farmers are efficient in all cases. It

  16. A Tale of Two Hot Spots: Charting Thermal Output Variations at Prometheus and Amirani from Galileo NIMS Data

    Science.gov (United States)

    Davies, A. G.

    2002-12-01

    Galileo Near Infrared Mapping Spectrometer (NIMS) data show that the active ionian volcanoes Prometheus and Amirani have significant thermal emission in excess of non-volcanic background emission in every geometrically appropriate NIMS observation. The 5 μm brightness of these volcanoes shows considerable variation from orbit to orbit. Like the flank eruptions on Kilauea, Hawai'i, which began in 1983, these ionian volcanoes exhibit periods of elevated activity. A study of the 5 μm thermal emission in all low-spatial resolution NIMS observations (both night and day-time) from June 1996 (Orbit G1) to May 2001 (Orbit C30) shows that the Prometheus thermal output (uncorrected for emission angle, e) ranges from 4 to 21 GW/μm, and Amirani shows greater variations, from 4 to 31 GW/μm. Correcting all thermal outputs for observations where estandard deviation of 7.3 GW/μm) and a larger average Amirani thermal output of 44 GW/μm (standard deviation of 26 GW/μm). Prometheus showed its greatest e-corrected thermal emission during November 1997 (33 GW/μm), more than four times that seen in June 1996 (orbit G1; see Davies et al., 2000, Icarus, 148, 212-225) and Amirani showed its greatest thermal emission during May 1997 (orbit G8), nearly 100 GW/μm, nearly five times that seen during orbit G1. Prometheus and Amirani spectra obtained at night show that the overall spectral shape of the thermal emission from 2 to 5 μm does not greatly change. The style of eruption is not resulting in disproportionately large areas at very high temperatures in relation to cooler crustal areas, such as seen at Pillan in 1997 and at Pele, indicating that the style of eruption is not changing, just the areal extent of activity. Scaling magma eruption rates derived from G1 NIMS data yields maximum and average volumetric eruption rates of 337 and 154 m3 s-1 for Amirani, and 128 and 52 m3 s-1 for Prometheus. The style and behavior of eruptions at Prometheus and Amirani are apparently very like

  17. Study of Interdependence of Wind Generation Output and Potential PV Generation in the Area of ENERGA-OPERATOR SA

    Directory of Open Access Journals (Sweden)

    Michał Bajor

    2016-09-01

    Full Text Available This paper presents the results of an analysis of the interdependence of wind generation output and photovoltaic generation potential in the ENERGA-OPERATOR SA grid. The first study of the interdependence of these two types of renewable sources’ generation outputs was carried out by the Gdańsk Branch of the Institute of Power Engineering in cooperation with ENERGA-OPERATOR in 2012. An important conclusion of the study was the need to repeat the analysis for a larger set of input data as the study covered the period of one year only, and for obvious reasons a limited number of wind farms. The present study’s inputs included a period of four years and more wind farms, due to the continuous connecting of new facilities to the grid. Thus, the results are characterized by a much higher level of credibility, and allow drawing mor correct conclusions regarding the analysed interdependence. The research on the interdependence of the annual wind generation output and potential generation from photovoltaic sources indicates that both generation types are characterized by mutual spatio-temporal dependency. In the study the relationship was quantified by evaluation of the maximum actual wind generation output in specific areas in the case of high PV generation output in a given area and vice versa. The results may allow for appropriate (i.e. substantiating the modelled operating conditions of the system in relation to reality consideration of both types of sources in various types of system analyses of their impact on the grid performance, such as interconnection studies for new sources and distribution grid development planning.

  18. Output formatting in Apple-Soft Basic

    International Nuclear Information System (INIS)

    Navale, A.S.

    1987-01-01

    Personal computers are being used extensively in various fields. BASIC is a very popular and widely used language in personal computers. Apple computer is one of the popular machines used for scientific and engineering applications. Presenting output from computers in a neat and easy to read form is very important. Languages like FORTRAN have utility command 'FORMAT' which takes care of the formatting of the output in user-defined form. In some versions of BASIC a PRINT USING facility is available but it is not as powerful as the FORTRAN statement 'FORMAT'. Applesoft basic does not have even this PRINT USING command. Programmers have to write their own program segments to handle output formatting in Applesoft BASIC. Generally, such user written programs are of limited use as they cannot be used easily with other programs. A general purpose and easily transportable subroutine in Applesoft BASIC is presented here for handling output formatting in user-defined structure. The subroutine is nearly as powerful as the FORMAT statement in FORTRAN. It can also be used in other versions of BASIC with very little modifications. 3 tables, 4 refs. (author)

  19. INFLUENCE OF FISCAL POLICY DYNAMICS ON OUTPUT MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Predescu Antoniu

    2013-04-01

    Full Text Available Dynamics of fiscal policy, more specific rise in fiscal pressure, increase which can be obtained either through enforcing one or more taxes, or by augmenting at least a tax, has a powerful impact on output management – visible, in the first place, in the realm of output size. But, not only output size will vary, after an increase in fiscal pressure, at least because output management is dealing with more than issue of producing a certain quantity of products, material or not, goods and/or services. Products are made for selling, but selling is impossible but through price and with a price; price is an essential economic variable, both in microeconomic and macroeconomic spheres. Thus, on one side rise in fiscal pressure determines, at least in short term, and, of course, if producers pay, or even support, a tax, be it newly enforced or (newly augmented, a rise of prices for sold products, and, on the other side, this results in a variation in output size, e.g. a reduced output volume, but, though, not in a linear trend. The dynamics, in this case of economic mechanism whose yield is a reduced volume of goods and/or services, in not linear, because essential are, too, the characteristics of products, from which effects of demand price elasticity and offer price elasticity influence significantly, in this framework, output management.

  20. The possibility to increase the rated output as a result of index tests performed in Iron Gates II- Romania

    Energy Technology Data Exchange (ETDEWEB)

    Novac, D; Pantelimon, D [Hidroelectrica - SH Portile de Fier, Str. I.G. Bibicescu Nr.2, Drobeta Turnu Severin, RO - 220103 (Romania); Popescu, E, E-mail: dragos.novac@hidroelectrica.r [Hidroelectrica Bucuresti, Str. C-tin Nacu Nr.3, Bucuresti, RO - 020995 (Romania)

    2010-08-15

    The Index Tests have been used for many years to obtain the optimized cam correlation between wicket gates and runner blades for double regulated turbines (Kaplan, bulb). The cam is based on homologous model tests and is verified by site measurements, as model tests generally do not reproduce the exact intake configuration. Index Tests have also a considerable importance for checking of the relative efficiency curve of all type of turbines and can demonstrate if the prototype efficiency curve at plant condition has the shape expected from the test of the homologues model. During the Index Tests measurements the influence of all losses at multiple points of turbine operation can be proved. This publication deals with an overview on the Index Tests made after modernization of large bulb units in Iron Gates II - Romania. These field tests, together with the comparative, fully homologous tests for the new hydraulic shape of the runner blades have confirmed the smooth operational behavior and the guaranteed performance. Over the whole 'guaranteed operating range' for H = 8m, the characteristic of the Kaplan curve (enveloping curve to the propeller curves), agreed very well to the predicted efficiency curve from the hydraulic prototype hill chart. The new cam correlation have been determined for different head and realised in the governor, normally based on model tests. The guaranteed, maximum turbine output for H = 7,8m is specified with 32, 5 MW. The maximum measured turbine output during the Index Tests on cam operation was 35,704 MW at the net head of 7,836 m. This corresponds to 35,458 MW for the specified head H= 7, 8 m. All these important improvements ensure a significant increase of annual energy production without any change of the civil construction and without increasing the runner diameter. Also the possibility to increase the turbine rated output is evident.

  1. The possibility to increase the rated output as a result of index tests performed in Iron Gates II- Romania

    Science.gov (United States)

    Novac, D.; Pantelimon, D.; Popescu, E.

    2010-08-01

    The Index Tests have been used for many years to obtain the optimized cam corellation between wicket gates and runner blades for double regulated turbines (Kaplan, bulb). The cam is based on homologous model tests and is verified by site measurements, as model tests generally do not reproduce the exact intake configuration. Index Tests have also a considerable importance for checking of the relative efficiency curve of all type of turbines and can demonstrate if the prototype efficiency curve at plant condition has the shape expected from the test of the homologues model. During the Index Tests measurements the influence of all losses at multiple points of turbine operation can be proved. This publication deals with an overview on the Index Tests made after modernization of large bulb units in Iron Gates II - Romania. These field tests, together with the comparative, fully homologous tests for the new hydraulic shape of the runner blades have confirmed the smooth operational behavior and the guaranteed performance. Over the whole "guaranteed operating range" for H = 8m, the characteristic of the Kaplan curve (enveloping curve to the proppeler curves), agreed very well to the predicted efficiency curve from the hydraulic prototype hill chart. The new cam correlation have been determined for different head and realised in the governor, normally based on model tests. The guaranteed, maximum turbine output for H = 7,8m is specified with 32, 5 MW. The maximum measured turbine output during the Index Tests on cam operation was 35,704 MW at the net head of 7,836 m. This coresponds to 35,458 MW for the specified head H= 7, 8 m. All these important improvements ensure a significant increase of annual energy production without any change of the civil construction and without increasing the runner diameter. Also the possibility to increase the turbine rated output is evident.

  2. The possibility to increase the rated output as a result of index tests performed in Iron Gates II- Romania

    International Nuclear Information System (INIS)

    Novac, D; Pantelimon, D; Popescu, E

    2010-01-01

    The Index Tests have been used for many years to obtain the optimized cam correlation between wicket gates and runner blades for double regulated turbines (Kaplan, bulb). The cam is based on homologous model tests and is verified by site measurements, as model tests generally do not reproduce the exact intake configuration. Index Tests have also a considerable importance for checking of the relative efficiency curve of all type of turbines and can demonstrate if the prototype efficiency curve at plant condition has the shape expected from the test of the homologues model. During the Index Tests measurements the influence of all losses at multiple points of turbine operation can be proved. This publication deals with an overview on the Index Tests made after modernization of large bulb units in Iron Gates II - Romania. These field tests, together with the comparative, fully homologous tests for the new hydraulic shape of the runner blades have confirmed the smooth operational behavior and the guaranteed performance. Over the whole 'guaranteed operating range' for H = 8m, the characteristic of the Kaplan curve (enveloping curve to the propeller curves), agreed very well to the predicted efficiency curve from the hydraulic prototype hill chart. The new cam correlation have been determined for different head and realised in the governor, normally based on model tests. The guaranteed, maximum turbine output for H = 7,8m is specified with 32, 5 MW. The maximum measured turbine output during the Index Tests on cam operation was 35,704 MW at the net head of 7,836 m. This corresponds to 35,458 MW for the specified head H= 7, 8 m. All these important improvements ensure a significant increase of annual energy production without any change of the civil construction and without increasing the runner diameter. Also the possibility to increase the turbine rated output is evident.

  3. Diode-Pumped Quasi-Three-Level Passively Q-Switched Nd:GGG Laser with a Codoped Nd,Cr:YAG Saturable Absorber

    International Nuclear Information System (INIS)

    Kun-Na, He; Chun-Qing, Gao; Zhi-Yi, Wei; Qi-Nan, Li; Zhi-Guo, Zhang; Hai-He, Jiang; Shao-Tang, Yin; Qing-Li, Zhang

    2009-01-01

    We demonstrate the first quasi-three-level passively Q-switched Nd:GGG laser at 937 nm using a Nd,Cr:YAG crystal as the saturable absorber. The dependences of the average output power, the repetition rate and the pulse width on the incident pump power are obtained. A maximum average output power of 1.18 W with repetition rate of 35 kHz and pulse width of 45 ns is achieved at an incident pump power of 18.3 W. The corresponding optical-to-optical and slope efficiencies are 6% and 10%, respectively

  4. A REVIEW OF EXPERIMENTAL STUDY OF POWER QUALITY MEASUREMENT OF PHOTOVOLTAIC CELLS WITH MAXIMUM POWER POINT TRACKING SYSTEM

    OpenAIRE

    Smriti Dwivedi; Prof. Sunil Kumar Bhatt

    2016-01-01

    Maximum power point tracking (MPPT) is a technique that charge controllers use for wind turbines and PV solar systems to maximize power output. PV solar systems exist in several different configurations. The most basic version sends power from collector panels directly to the DC-AC inverter and from there directly to the electrical grid. A second version, called a hybrid inverter, might split the power at the inverter, where a percentage of the power goes to the grid and the remainder goes to...

  5. Growth and maximum size of tiger sharks (Galeocerdo cuvier) in Hawaii.

    Science.gov (United States)

    Meyer, Carl G; O'Malley, Joseph M; Papastamatiou, Yannis P; Dale, Jonathan J; Hutchinson, Melanie R; Anderson, James M; Royer, Mark A; Holland, Kim N

    2014-01-01

    Tiger sharks (Galecerdo cuvier) are apex predators characterized by their broad diet, large size and rapid growth. Tiger shark maximum size is typically between 380 & 450 cm Total Length (TL), with a few individuals reaching 550 cm TL, but the maximum size of tiger sharks in Hawaii waters remains uncertain. A previous study suggested tiger sharks grow rather slowly in Hawaii compared to other regions, but this may have been an artifact of the method used to estimate growth (unvalidated vertebral ring counts) compounded by small sample size and narrow size range. Since 1993, the University of Hawaii has conducted a research program aimed at elucidating tiger shark biology, and to date 420 tiger sharks have been tagged and 50 recaptured. All recaptures were from Hawaii except a single shark recaptured off Isla Jacques Cousteau (24°13'17″N 109°52'14″W), in the southern Gulf of California (minimum distance between tag and recapture sites  =  approximately 5,000 km), after 366 days at liberty (DAL). We used these empirical mark-recapture data to estimate growth rates and maximum size for tiger sharks in Hawaii. We found that tiger sharks in Hawaii grow twice as fast as previously thought, on average reaching 340 cm TL by age 5, and attaining a maximum size of 403 cm TL. Our model indicates the fastest growing individuals attain 400 cm TL by age 5, and the largest reach a maximum size of 444 cm TL. The largest shark captured during our study was 464 cm TL but individuals >450 cm TL were extremely rare (0.005% of sharks captured). We conclude that tiger shark growth rates and maximum sizes in Hawaii are generally consistent with those in other regions, and hypothesize that a broad diet may help them to achieve this rapid growth by maximizing prey consumption rates.

  6. Theoretical assessment of the maximum power point tracking efficiency of photovoltaic facilities with different converter topologies

    Energy Technology Data Exchange (ETDEWEB)

    Enrique, J.M.; Duran, E.; Andujar, J.M. [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva (Spain); Sidrach-de-Cardona, M. [Departamento de Fisica Aplicada, II, Universidad de Malaga (Spain)

    2007-01-15

    The operating point of a photovoltaic generator that is connected to a load is determined by the intersection point of its characteristic curves. In general, this point is not the same as the generator's maximum power point. This difference means losses in the system performance. DC/DC converters together with maximum power point tracking systems (MPPT) are used to avoid these losses. Different algorithms have been proposed for maximum power point tracking. Nevertheless, the choice of the configuration of the right converter has not been studied so widely, although this choice, as demonstrated in this work, has an important influence in the optimum performance of the photovoltaic system. In this article, we conduct a study of the three basic topologies of DC/DC converters with resistive load connected to photovoltaic modules. This article demonstrates that there is a limitation in the system's performance according to the type of converter used. Two fundamental conclusions are derived from this study: (1) the buck-boost DC/DC converter topology is the only one which allows the follow-up of the PV module maximum power point regardless of temperature, irradiance and connected load and (2) the connection of a buck-boost DC/DC converter in a photovoltaic facility to the panel output could be a good practice to improve performance. (author)

  7. MPBoot: fast phylogenetic maximum parsimony tree inference and bootstrap approximation.

    Science.gov (United States)

    Hoang, Diep Thi; Vinh, Le Sy; Flouri, Tomáš; Stamatakis, Alexandros; von Haeseler, Arndt; Minh, Bui Quang

    2018-02-02

    The nonparametric bootstrap is widely used to measure the branch support of phylogenetic trees. However, bootstrapping is computationally expensive and remains a bottleneck in phylogenetic analyses. Recently, an ultrafast bootstrap approximation (UFBoot) approach was proposed for maximum likelihood analyses. However, such an approach is still missing for maximum parsimony. To close this gap we present MPBoot, an adaptation and extension of UFBoot to compute branch supports under the maximum parsimony principle. MPBoot works for both uniform and non-uniform cost matrices. Our analyses on biological DNA and protein showed that under uniform cost matrices, MPBoot runs on average 4.7 (DNA) to 7 times (protein data) (range: 1.2-20.7) faster than the standard parsimony bootstrap implemented in PAUP*; but 1.6 (DNA) to 4.1 times (protein data) slower than the standard bootstrap with a fast search routine in TNT (fast-TNT). However, for non-uniform cost matrices MPBoot is 5 (DNA) to 13 times (protein data) (range:0.3-63.9) faster than fast-TNT. We note that MPBoot achieves better scores more frequently than PAUP* and fast-TNT. However, this effect is less pronounced if an intensive but slower search in TNT is invoked. Moreover, experiments on large-scale simulated data show that while both PAUP* and TNT bootstrap estimates are too conservative, MPBoot bootstrap estimates appear more unbiased. MPBoot provides an efficient alternative to the standard maximum parsimony bootstrap procedure. It shows favorable performance in terms of run time, the capability of finding a maximum parsimony tree, and high bootstrap accuracy on simulated as well as empirical data sets. MPBoot is easy-to-use, open-source and available at http://www.cibiv.at/software/mpboot .

  8. Assessing the psychological factors predicting workers' output ...

    African Journals Online (AJOL)

    The study investigated job security, communication skills, interpersonal relationship and emotional intelligence as correlates of workers' output among local government employees in Oyo State. The research adopted descriptive design of an expose facto type. The research instruments used includes Workers' output scale, ...

  9. Problems in Modelling Charge Output Accelerometers

    Directory of Open Access Journals (Sweden)

    Tomczyk Krzysztof

    2016-12-01

    Full Text Available The paper presents major issues associated with the problem of modelling change output accelerometers. The presented solutions are based on the weighted least squares (WLS method using transformation of the complex frequency response of the sensors. The main assumptions of the WLS method and a mathematical model of charge output accelerometers are presented in first two sections of this paper. In the next sections applying the WLS method to estimation of the accelerometer model parameters is discussed and the associated uncertainties are determined. Finally, the results of modelling a PCB357B73 charge output accelerometer are analysed in the last section of this paper. All calculations were executed using the MathCad software program. The main stages of these calculations are presented in Appendices A−E.

  10. Evaluation of probable maximum snow accumulation: Development of a methodology for climate change studies

    Science.gov (United States)

    Klein, Iris M.; Rousseau, Alain N.; Frigon, Anne; Freudiger, Daphné; Gagnon, Patrick

    2016-06-01

    Probable maximum snow accumulation (PMSA) is one of the key variables used to estimate the spring probable maximum flood (PMF). A robust methodology for evaluating the PMSA is imperative so the ensuing spring PMF is a reasonable estimation. This is of particular importance in times of climate change (CC) since it is known that solid precipitation in Nordic landscapes will in all likelihood change over the next century. In this paper, a PMSA methodology based on simulated data from regional climate models is developed. Moisture maximization represents the core concept of the proposed methodology; precipitable water being the key variable. Results of stationarity tests indicate that CC will affect the monthly maximum precipitable water and, thus, the ensuing ratio to maximize important snowfall events. Therefore, a non-stationary approach is used to describe the monthly maximum precipitable water. Outputs from three simulations produced by the Canadian Regional Climate Model were used to give first estimates of potential PMSA changes for southern Quebec, Canada. A sensitivity analysis of the computed PMSA was performed with respect to the number of time-steps used (so-called snowstorm duration) and the threshold for a snowstorm to be maximized or not. The developed methodology is robust and a powerful tool to estimate the relative change of the PMSA. Absolute results are in the same order of magnitude as those obtained with the traditional method and observed data; but are also found to depend strongly on the climate projection used and show spatial variability.

  11. An experimental extrapolation technique using the Gafchromic EBT3 film for relative output factor measurements in small x-ray fields

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Johnny E., E-mail: johnny.morales@lh.org.au [Department of Radiation Oncology, Chris O’Brien Lifehouse, 119-143 Missenden Road, Camperdown, NSW 2050, Australia and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Level 4 O Block, Garden’s Point, QLD 4001 (Australia); Butson, Martin; Hill, Robin [Department of Radiation Oncology, Chris O’Brien Lifehouse, 119-143 Missenden Road, Camperdown, NSW 2050, Australia and Institute of Medical Physics, University of Sydney, NSW 2006 (Australia); Crowe, Scott B. [School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Level 4 O Block, Garden’s Point, QLD 4001, Australia and Cancer Care Services, Royal Brisbane and Women’s Hospital, Butterfield Street, Herston, QLD 4029 (Australia); Trapp, J. V. [School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Level 4 O Block, Garden’s Point, QLD 4001 (Australia)

    2016-08-15

    Purpose: An experimental extrapolation technique is presented, which can be used to determine the relative output factors for very small x-ray fields using the Gafchromic EBT3 film. Methods: Relative output factors were measured for the Brainlab SRS cones ranging in diameters from 4 to 30 mm{sup 2} on a Novalis Trilogy linear accelerator with 6 MV SRS x-rays. The relative output factor was determined from an experimental reducing circular region of interest (ROI) extrapolation technique developed to remove the effects of volume averaging. This was achieved by scanning the EBT3 film measurements with a high scanning resolution of 1200 dpi. From the high resolution scans, the size of the circular regions of interest was varied to produce a plot of relative output factors versus area of analysis. The plot was then extrapolated to zero to determine the relative output factor corresponding to zero volume. Results: Results have shown that for a 4 mm field size, the extrapolated relative output factor was measured as a value of 0.651 ± 0.018 as compared to 0.639 ± 0.019 and 0.633 ± 0.021 for 0.5 and 1.0 mm diameter of analysis values, respectively. This showed a change in the relative output factors of 1.8% and 2.8% at these comparative regions of interest sizes. In comparison, the 25 mm cone had negligible differences in the measured output factor between zero extrapolation, 0.5 and 1.0 mm diameter ROIs, respectively. Conclusions: This work shows that for very small fields such as 4.0 mm cone sizes, a measureable difference can be seen in the relative output factor based on the circular ROI and the size of the area of analysis using radiochromic film dosimetry. The authors recommend to scan the Gafchromic EBT3 film at a resolution of 1200 dpi for cone sizes less than 7.5 mm and to utilize an extrapolation technique for the output factor measurements of very small field dosimetry.

  12. Simulation of Distributed PV Power Output in Oahu Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Lave, Matthew Samuel [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2016-08-01

    Distributed solar photovoltaic (PV) power generation in Oahu has grown rapidly since 2008. For applications such as determining the value of energy storage, it is important to have PV power output timeseries. Since these timeseries of not typically measured, here we produce simulated distributed PV power output for Oahu. Simulated power output is based on (a) satellite-derived solar irradiance, (b) PV permit data by neighborhood, and (c) population data by census block. Permit and population data was used to model locations of distributed PV, and irradiance data was then used to simulate power output. PV power output simulations are presented by sub-neighborhood polygons, neighborhoods, and for the whole island of Oahu. Summary plots of annual PV energy and a sample week timeseries of power output are shown, and a the files containing the entire timeseries are described.

  13. Exploiting maximum energy from variable speed wind power generation systems by using an adaptive Takagi-Sugeno-Kang fuzzy model

    International Nuclear Information System (INIS)

    Galdi, V.; Piccolo, A.; Siano, P.

    2009-01-01

    Nowadays, incentives and financing options for developing renewable energy facilities and the new development in variable speed wind technology make wind energy a competitive source if compared with conventional generation ones. In order to improve the effectiveness of variable speed wind systems, adaptive control systems able to cope with time variances of the system under control are necessary. On these basis, a data driven designing methodology for TSK fuzzy models design is presented in this paper. The methodology, on the basis of given input-output numerical data, generates the 'best' TSK fuzzy model able to estimate with high accuracy the maximum extractable power from a variable speed wind turbine. The design methodology is based on fuzzy clustering methods for partitioning the input-output space combined with genetic algorithms (GA), and recursive least-squares (LS) optimization methods for model parameter adaptation

  14. Complementary power output characteristics of electromagnetic generators and triboelectric generators.

    Science.gov (United States)

    Fan, Feng-Ru; Tang, Wei; Yao, Yan; Luo, Jianjun; Zhang, Chi; Wang, Zhong Lin

    2014-04-04

    Recently, a triboelectric generator (TEG) has been invented to convert mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction. Compared to the traditional electromagnetic generator (EMG) that produces a high output current but low voltage, the TEG has different output characteristics of low output current but high output voltage. In this paper, we present a comparative study regarding the fundamentals of TEGs and EMGs. The power output performances of the EMG and the TEG have a special complementary relationship, with the EMG being a voltage source and the TEG a current source. Utilizing a power transformed and managed (PTM) system, the current output of a TEG can reach as high as ∼3 mA, which can be coupled with the output signal of an EMG to enhance the output power. We also demonstrate a design to integrate a TEG and an EMG into a single device for simultaneously harvesting mechanical energy. In addition, the integrated NGs can independently output a high voltage and a high current to meet special needs.

  15. Fast metabolite identification with Input Output Kernel Regression

    Science.gov (United States)

    Brouard, Céline; Shen, Huibin; Dührkop, Kai; d'Alché-Buc, Florence; Böcker, Sebastian; Rousu, Juho

    2016-01-01

    Motivation: An important problematic of metabolomics is to identify metabolites using tandem mass spectrometry data. Machine learning methods have been proposed recently to solve this problem by predicting molecular fingerprint vectors and matching these fingerprints against existing molecular structure databases. In this work we propose to address the metabolite identification problem using a structured output prediction approach. This type of approach is not limited to vector output space and can handle structured output space such as the molecule space. Results: We use the Input Output Kernel Regression method to learn the mapping between tandem mass spectra and molecular structures. The principle of this method is to encode the similarities in the input (spectra) space and the similarities in the output (molecule) space using two kernel functions. This method approximates the spectra-molecule mapping in two phases. The first phase corresponds to a regression problem from the input space to the feature space associated to the output kernel. The second phase is a preimage problem, consisting in mapping back the predicted output feature vectors to the molecule space. We show that our approach achieves state-of-the-art accuracy in metabolite identification. Moreover, our method has the advantage of decreasing the running times for the training step and the test step by several orders of magnitude over the preceding methods. Availability and implementation: Contact: celine.brouard@aalto.fi Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27307628

  16. Novel high accurate sensorless dual-axis solar tracking system controlled by maximum power point tracking unit of photovoltaic systems

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2016-01-01

    Highlights: • Novel high accurate sensorless dual-axis solar tracker. • It has the advantages of both sensor based and sensorless solar trackers. • It does not have the disadvantages of sensor based and sensorless solar trackers. • Tracking error of only 0.11° that is less than the tracking errors of others. • An increase of 28.8–43.6% depending on the seasons in the energy efficiency. - Abstract: In this study, a novel high accurate sensorless dual-axis solar tracker controlled by the maximum power point tracking unit available in almost all photovoltaic systems is proposed. The maximum power point tracking controller continuously calculates the maximum output power of the photovoltaic module/panel/array, and uses the altitude and azimuth angles deviations to track the sun direction where the greatest value of the maximum output power is extracted. Unlike all other sensorless solar trackers, the proposed solar tracking system is a closed loop system which means it uses the actual direction of the sun at any time to track the sun direction, and this is the contribution of this work. The proposed solar tracker has the advantages of both sensor based and sensorless dual-axis solar trackers, but it does not have their disadvantages. Other sensorless solar trackers all are open loop, i.e., they use offline estimated data about the sun path in the sky obtained from solar map equations, so low exactness, cloudy sky, and requiring new data for new location are their problems. A photovoltaic system has been built, and it is experimentally verified that the proposed solar tracking system tracks the sun direction with the tracking error of 0.11° which is less than the tracking errors of other both sensor based and sensorless solar trackers. An increase of 28.8–43.6% depending on the seasons in the energy efficiency is the main advantage of utilizing the proposed solar tracking system.

  17. Method and apparatus for current-output peak detection

    Science.gov (United States)

    De Geronimo, Gianluigi

    2017-01-24

    A method and apparatus for a current-output peak detector. A current-output peak detector circuit is disclosed and works in two phases. The peak detector circuit includes switches to switch the peak detector circuit from the first phase to the second phase upon detection of the peak voltage of an input voltage signal. The peak detector generates a current output with a high degree of accuracy in the second phase.

  18. Industrial output restriction and the Kyoto protocol. An input-output approach with application to Canada

    International Nuclear Information System (INIS)

    Lixon, Benoit; Thomassin, Paul J.; Hamaide, Bertrand

    2008-01-01

    The objective of this paper is to assess the economic impacts of reducing greenhouse gas emissions by decreasing industrial output in Canada to a level that will meet the target set out in the Kyoto Protocol. The study uses an ecological-economic Input-Output model combining economic components valued in monetary terms with ecologic components - GHG emissions - expressed in physical terms. Economic and greenhouse gas emissions data for Canada are computed in the same sectoral disaggregation. Three policy scenarios are considered: the first one uses the direct emission coefficients to allocate the reduction in industrial output, while the other two use the direct plus indirect emission coefficients. In the first two scenarios, the reduction in industrial sector output is allocated uniformly across sectors while it is allocated to the 12 largest emitting industries in the last one. The estimated impacts indicate that the results vary with the different allocation methods. The third policy scenario, allocation to the 12 largest emitting sectors, is the most cost effective of the three as the impacts of the Kyoto Protocol reduces Gross Domestic Product by 3.1% compared to 24% and 8.1% in the first two scenarios. Computed economic costs should be considered as upper-bounds because the model assumes immediate adjustment to the Kyoto Protocol and because flexibility mechanisms are not incorporated. The resulting upper-bound impact of the third scenario may seem to contradict those who claim that the Kyoto Protocol would place an unbearable burden on the Canadian economy. (author)

  19. Highly efficient maximum power point tracking using DC-DC coupled inductor single-ended primary inductance converter for photovoltaic power systems

    Science.gov (United States)

    Quamruzzaman, M.; Mohammad, Nur; Matin, M. A.; Alam, M. R.

    2016-10-01

    Solar photovoltaics (PVs) have nonlinear voltage-current characteristics, with a distinct maximum power point (MPP) depending on factors such as solar irradiance and operating temperature. To extract maximum power from the PV array at any environmental condition, DC-DC converters are usually used as MPP trackers. This paper presents the performance analysis of a coupled inductor single-ended primary inductance converter for maximum power point tracking (MPPT) in a PV system. A detailed model of the system has been designed and developed in MATLAB/Simulink. The performance evaluation has been conducted on the basis of stability, current ripple reduction and efficiency at different operating conditions. Simulation results show considerable ripple reduction in the input and output currents of the converter. Both the MPPT and converter efficiencies are significantly improved. The obtained simulation results validate the effectiveness and suitability of the converter model in MPPT and show reasonable agreement with the theoretical analysis.

  20. Monetary policy and regional output in Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Rockenbach da Silva Guimarães

    2014-03-01

    Full Text Available This work presents an analysis of whether the effects of the Brazilian monetary policy on regional outputs are symmetric. The strategy developed combines the techniques of principal component analysis (PCA to decompose the variables that measure regional economic activity into common and region-specific components and vector autoregressions (VAR to observe the behavior of these variables in response to monetary policy shocks. The common component responds to monetary policy as expected. Additionally, the idiosyncratic components of the regions showed no impact of monetary policy. The main finding of this paper is that the monetary policy responses on regional output are symmetrical when the regional output decomposition is performed, and the responses are asymmetrical when this decomposition is not performed. Therefore, performing the regional output decomposition corroborates the economic intuition that monetary policy has no impact on region-specific issues. Once monetary policy affects the common component of the regional economic activity and does not impact its idiosyncratic components, it can be considered symmetrical.

  1. Comparing between predicted output temperature of flat-plate solar collector and experimental results: computational fluid dynamics and artificial neural network

    Directory of Open Access Journals (Sweden)

    F Nadi

    2017-05-01

    back propagation learning rule was used to simulate the output temperature of a solar collector. The number of neurons within the hidden layer varied from 1 to 20. The hyperbolic tan- sigmoid and pure-line were used as the transfer function in the hidden layer and output layer, respectively. Minimization of error was achieved using the Levenberg-Marquardt algorithm. To carry out the aforementioned steps, the dataset (105 observations was split into training (70 observations, and test (35 observations data. Training sets used to develop models included air velocity, solar radiation, time of the day, ambient moisture and temperature values as inputs with an associated temperature of the collector as outputs. The aim of every training algorithm is to reduce this global error by adjusting the weights and biases. Results and Discussion Compare experimental results with ANN The performance of the three-layer ANN for the prediction of output temperature of flat-plate solar collector by the Levenberg–Marquardt training algorithm was illustrated in Fig. 4. ANN predicted output temperatures with R2 and RMSE of 0.92 and 1.23, respectively. Furthermore, the maximum error in prediction of output temperature of solar collector was 3.3 K. These results are in agreement with Tripathy and Kumar, (2009 those who have predicted the output temperatures of food product in the solar drier using ANN with and RMSE of 0.95 and 0.77, respectively. Compare experimental results with CFD simulation Fig. 6 shows that over the starting length of the absorber plate, there is a variation of the velocity profile which is caused by sharp geometry and it leads to some recirculation of the air in this part of absorber plate. After this part of boundary layers, flow is fully developed and velocity profile becomes smoother and constant. Fig. 8 shows that the predicted temperature was within the experimentally measured temperature. The highest differences between simulated and experimental temperatures

  2. Deep brain stimulation changes basal ganglia output nuclei firing pattern in the dystonic hamster.

    Science.gov (United States)

    Leblois, Arthur; Reese, René; Labarre, David; Hamann, Melanie; Richter, Angelika; Boraud, Thomas; Meissner, Wassilios G

    2010-05-01

    Dystonia is a heterogeneous syndrome of movement disorders characterized by involuntary muscle contractions leading to abnormal movements and postures. While medical treatment is often ineffective, deep brain stimulation (DBS) of the internal pallidum improves dystonia. Here, we studied the impact of DBS in the entopeduncular nucleus (EP), the rodent equivalent of the human globus pallidus internus, on basal ganglia output in the dt(sz)-hamster, a well-characterized model of dystonia by extracellular recordings. Previous work has shown that EP-DBS improves dystonic symptoms in dt(sz)-hamsters. We report that EP-DBS changes firing pattern in the EP, most neurons switching to a less regular firing pattern during DBS. In contrast, EP-DBS did not change the average firing rate of EP neurons. EP neurons display multiphasic responses to each stimulation impulse, likely underlying the disruption of their firing rhythm. Finally, neurons in the substantia nigra pars reticulata display similar responses to EP-DBS, supporting the idea that EP-DBS affects basal ganglia output activity through the activation of common afferent fibers. Copyright 2010 Elsevier Inc. All rights reserved.

  3. VMS forms Output Tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These output tables contain parsed and format validated data from the various VMS forms that are sent from any given vessel, while at sea, from the VMS devices on...

  4. Output calculation of electron therapy at extended SSD using an improved LBR method

    Energy Technology Data Exchange (ETDEWEB)

    Alkhatib, Hassaan A.; Gebreamlak, Wondesen T., E-mail: wondtassew@gmail.com; Wright, Ben W.; Neglia, William J. [South Carolina Oncology Associates, Columbia, South Carolina 29210 (United States); Tedeschi, David J. [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States); Mihailidis, Dimitris [CAMC Cancer Center and Alliance Oncology, Charleston, West Virginia 25304 (United States); Sobash, Philip T. [The Medical University of South Carolina, Charleston, South Carolina 29425 (United States); Fontenot, Jonas D. [Department of Physics, Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana 70809 (United States)

    2015-02-15

    Purpose: To calculate the output factor (OPF) of any irregularly shaped electron beam at extended SSD. Methods: Circular cutouts were prepared from 2.0 cm diameter to the maximum possible size for 15 × 15 applicator cone. In addition, two irregular cutouts were prepared. For each cutout, percentage depth dose (PDD) at the standard SSD and doses at different SSD values were measured using 6, 9, 12, and 16 MeV electron beam energies on a Varian 2100C LINAC and the distance at which the central axis electron fluence becomes independent of cutout size was determined. The measurements were repeated with an ELEKTA Synergy LINAC using 14 × 14 applicator cone and electron beam energies of 6, 9, 12, and 15 MeV. The PDD measurements were performed using a scanning system and two diodes—one for the signal and the other a stationary reference outside the tank. The doses of the circular cutouts at different SSDs were measured using PTW 0.125 cm{sup 3} Semiflex ion-chamber and EDR2 films. The electron fluence was measured using EDR2 films. Results: For each circular cutout, the lateral buildup ratio (LBR) was calculated from the measured PDD curve using the open applicator cone as the reference field. The effective SSD (SSD{sub eff}) of each circular cutout was calculated from the measured doses at different SSD values. Using the LBR value and the radius of the circular cutout, the corresponding lateral spread parameter [σ{sub R}(z)] was calculated. Taking the cutout size dependence of σ{sub R}(z) into account, the PDD curves of the irregularly shaped cutouts at the standard SSD were calculated. Using the calculated PDD curve of the irregularly shaped cutout along with the LBR and SSD{sub eff} values of the circular cutouts, the output factor of the irregularly shaped cutout at extended SSD was calculated. Finally, both the calculated PDD curves and output factor values were compared with the measured values. Conclusions: The improved LBR method has been generalized to

  5. INPUT-OUTPUT ANALYSIS : THE NEXT 25 YEARS

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Lenzen, Manfred; Los, Bart; Guan, Dabo; Lahr, Michael L.; Sancho, Ferran; Suh, Sangwon; Yang, Cuihong; Sancho, S.

    2013-01-01

    This year marks the 25th anniversary of the International Input-Output Association and the 25th volume of Economic Systems Research. To celebrate this anniversary, a group of eight experts provide their views on the future of input-output. Looking forward, they foresee progress in terms of data

  6. Fiscal 1998 survey report. Assessment and analysis of collected data in wind power generation field test project; 1998 nendo furyoku hatsuden field test jigyo ni okeru shushu data hyoka kaiseki chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Examination was made on wind conditions, power generating characteristics, and the reliability of a system by analyzing the operation record of the wind power generation equipment which was installed at Hiraizumi-cho, Nishi-Iwai gun, Iwate prefecture and at Misaki-cho, Miura-shi, Kanagawa prefecture. The equipment at Hiraizumi had a rated output of 490 kW, and at Miura 400 kW. The period of the examination was from April, 1998 through February, 1999, the items for data collection being the generator output, generated energy, average wind velocity, record of abnormality occurrence, and maximum wind velocity. At Hiraizumi, annual average utilization rate was 12.9%; annual average operation rate, 49.9%; average wind velocity, 4.6 m/s; and maximum wind velocity of the period, 31 m/s. At Miura, annual average utilization rate was 16.5%; annual average operation rate, 77.0%; and average wind velocity, 5.0 m/s. The utilization rate is desirably 17%. The top three abnormalities were drop in AC control voltage, actuation of main shaft brake and eddy current/actuation of open phase relay, accounting for 83.3% of the total abnormalities at Hiraizumi, while they were unbalance in current, grid drop and automatic unwinding of cable, accounting for 74.5% at Miura. (NEDO)

  7. SU-F-T-143: Implementation of a Correction-Based Output Model for a Compact Passively Scattered Proton Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, S; Ahmad, S; Chen, Y; Ferreira, C; Islam, M; Lau, A; Jin, H [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Keeling, V [Carti, Inc., Little Rock, AR (United States)

    2016-06-15

    Purpose: To commission and investigate the accuracy of an output (cGy/MU) prediction model for a compact passively scattered proton therapy system. Methods: A previously published output prediction model (Sahoo et al, Med Phys, 35, 5088–5097, 2008) was commissioned for our Mevion S250 proton therapy system. This model is a correction-based model that multiplies correction factors (d/MUwnc=ROFxSOBPF xRSFxSOBPOCFxOCRxFSFxISF). These factors accounted for changes in output due to options (12 large, 5 deep, and 7 small), modulation width M, range R, off-center, off-axis, field-size, and off-isocenter. In this study, the model was modified to ROFxSOBPFxRSFxOCRxFSFxISF-OCFxGACF by merging SOBPOCF and ISF for simplicity and introducing a gantry angle correction factor (GACF). To commission the model, outputs over 1,000 data points were taken at the time of the system commissioning. The output was predicted by interpolation (1D for SOBPF, FSF, and GACF; 2D for RSF and OCR) with inverse-square calculation (ISF-OCR). The outputs of 273 combinations of R and M covering total 24 options were measured to test the model. To minimize fluence perturbation, scattered dose from range compensator and patient was not considered. The percent differences between the predicted (P) and measured (M) outputs were calculated to test the prediction accuracy ([P-M]/Mx100%). Results: GACF was required because of up to 3.5% output variation dependence on the gantry angle. A 2D interpolation was required for OCR because the dose distribution was not radially symmetric especially for the deep options. The average percent differences were −0.03±0.98% (mean±SD) and the differences of all the measurements fell within ±3%. Conclusion: It is concluded that the model can be clinically used for the compact passively scattered proton therapy system. However, great care should be taken when the field-size is less than 5×5 cm{sup 2} where a direct output measurement is required due to substantial

  8. Neutron resonance averaging

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1986-10-01

    The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs

  9. Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

    Science.gov (United States)

    Hall, Alex; Taylor, Andy

    2017-06-01

    We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

  10. Influence of epoxy resin as encapsulation material of silicon photovoltaic cells on maximum current

    Directory of Open Access Journals (Sweden)

    Acevedo-Gómez David

    2017-01-01

    Full Text Available This work presents an analysis about how the performance of silicon photovoltaic cells is influenced by the use of epoxy resin as encapsulation material with flat roughness. The effect of encapsulation on current at maximum power of mono-crystalline cell was tested indoor in a solar simulator bench at 1000 w/m² and AM1.5G. The results show that implementation of flat roughness layer onto cell surface reduces the maximum current inducing on average 2.7% less power with respect to a cell before any encapsulation. The losses of power and, in consequence, the less production of energy are explained by resin light absorption, reflection and partially neutralization of non-reflective coating.

  11. Scientific Output of Croatian Universities: Comparison with Neighbouring Countries

    Directory of Open Access Journals (Sweden)

    Boris Podobnik

    2008-06-01

    Full Text Available We compared the Croatian research output with the neighboring countries and the Croatian universities with the largest Slovenian, Hungarian, and Serbian universities. As far as papers listed by Social Science Citation Index are concerned, since 2000 the University of Zagreb exhibits best results in social sciences compared to the competing universities, that is not the case in “hard” sciences. For the last 12 years, only the University of Ljubljana has shown better results in total research output than the University of Zagreb. The difference in research output between the University of Zagreb and the rest of the Croatian universities has been constantly decreasing. As a case study we compare research output at Faculty of Civil Engeenering on different Croatian universities. By analyzing European countries, we show a functional dependence between the gross domestic product (GDP and the research output. From this fit we conclude that the Croatian science exhibits research output as expected for the given level of GDP.

  12. The average baboon brain: MRI templates and tissue probability maps from 89 individuals.

    Science.gov (United States)

    Love, Scott A; Marie, Damien; Roth, Muriel; Lacoste, Romain; Nazarian, Bruno; Bertello, Alice; Coulon, Olivier; Anton, Jean-Luc; Meguerditchian, Adrien

    2016-05-15

    The baboon (Papio) brain is a remarkable model for investigating the brain. The current work aimed at creating a population-average baboon (Papio anubis) brain template and its left/right hemisphere symmetric version from a large sample of T1-weighted magnetic resonance images collected from 89 individuals. Averaging the prior probability maps output during the segmentation of each individual also produced the first baboon brain tissue probability maps for gray matter, white matter and cerebrospinal fluid. The templates and the tissue probability maps were created using state-of-the-art, freely available software tools and are being made freely and publicly available: http://www.nitrc.org/projects/haiko89/ or http://lpc.univ-amu.fr/spip.php?article589. It is hoped that these images will aid neuroimaging research of the baboon by, for example, providing a modern, high quality normalization target and accompanying standardized coordinate system as well as probabilistic priors that can be used during tissue segmentation. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Changes in atmospheric circulation between solar maximum and minimum conditions in winter and summer

    Science.gov (United States)

    Lee, Jae Nyung

    2008-10-01

    convective region in solar maximum compared to solar minimum for January and July. The column integrated humidity in all the model experiments with different composition, different solar forcing, and different ocean module, increased with solar forcing in the tropical band over the Atlantic sector in both seasons. The model's humidity response pattern is generally consistent with the paleoclimate records indicating increased precipitation near the equator that decreases at subtropical to middle latitudes with increased solar output. The differences in the zonally averaged vertical velocities indicate that the ascending branch of the Hadley cell is enhanced and shifted northward, and that the descending branch is weakened and shifted northward in the solar MAX simulation in January. The downward branch of the Hadley cell is strengthened in MAX in July. A possible link of climate response in midlatitudes to solar forcing is also presented by showing changes in zonal mean wind, changes in temperature gradient, and changes in E-P flux.

  14. Chromospheric oscillations observed with OSO 8. III. Average phase spectra for Si II

    International Nuclear Information System (INIS)

    White, O.R.; Athay, R.G.

    1979-01-01

    Time series of intensity and Doppler-shift fluctuations in the Si II emission lines lambda816.93 and lambda817.45 are Fourier analyzed to determine the frequency variation of phase differences between intensity and velocity and between these two lines formed 300 km apart in the middle chromosphere. Average phase spectra show that oscillations between 2 and 9 mHz in the two lines have time delays from 35 to 40 s, which is consistent with the upward propagation of sound wave at 8.6-7.5 km s -1 . In this same frequency band near 3 mHz, maximum brightness leads maximum blueshift by 60 0 . At frequencies above 11 mHz where the power spectrum is flat, the phase differences are uncertain, but approximately 65% of the cases indicate upward propagation. At these higher frequencies, the phase lead between intensity and blue Doppler shift ranges from 0 0 to 180 0 with an average value of 90 0 . However, the phase estimates in this upper band are corrupted by both aliasing and randomness inherent to the measured signals. Phase differences in the two narrow spectral features seen at 10.5 and 27 mHz in the power spectra are shown to be consistent with properties expected for aliases of the wheel rotation rate of the spacecraft wheel section

  15. Maximum power point tracking controller for PV systems using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Bahgat, A.B.G. [Cairo Univ. (Egypt). Faculty of Engineering; Helwa, N.H.; Ahmad, G.E.; El Shenawy, E.T. [National Research Center, Dokki, Cairo (Egypt). Solar Energy Dept.

    2005-07-01

    This paper presents a development and implementation of a PC-based maximum power point tracker (MPPT) for PV system using neural networks (NN). The system consists of a PV module via a MPPT supplying a dc motor that drives an air fan. The control algorithm is developed to use the artificial NN for detecting the optimal operating point under different operating conditions, then the control action gives the driving signals to the MPPT. A PC is used for data acquisition, running the control algorithm, data storage, as well as data display and analysis. The system has been implemented and tested under various operating conditions. The experimental results showed that the PV system with MPPT always tracks the peak power point of the PV module under various operating conditions. The MPPT transmits about 97% of the actual maximum power generated by the PV module. The MPPT not only increases the power from the PV module to the load, but also maintains longer operating periods for the PV system. The air velocity and the air mass flow rate of the mechanical load are increased considerably, due to the increase of the PV system power. It is also found that the increase in the output energy due to using the MPPT is about 45.2% for a clear sunny day. (Author)

  16. Oral diosmectite reduces stool output and diarrhea duration in children with acute watery diarrhea.

    Science.gov (United States)

    Dupont, Christophe; Foo, Jimmy Lee Kok; Garnier, Philippe; Moore, Nicholas; Mathiex-Fortunet, Hèlène; Salazar-Lindo, Eduardo

    2009-04-01

    Diosmectite is a clay used to treat children with acute watery diarrhea. However, its effects on stool output reduction, the key outcome for pediatric antidiarrheal drugs, have not been shown. Two parallel, double-blind studies of diosmectite efficacy on stool reduction were conducted in children 1 to 36 months old in Peru (n = 300) and Malaysia (n = 302). Inclusion criteria included 3 or more watery stools per day for less than 72 hours and weight/height ratios of 0.8 or greater. Exclusion criteria were the need for intravenous rehydration, gross blood in stools, fever higher than 39 degrees C, or current treatment with antidiarrheal or antibiotic medications. Rotavirus status was determined. Diosmectite dosage was 6 g/day (children 1-12 months old) or 12 g/day (children 13-36 months old), given for at least 3 days, followed by half doses until complete recovery. Patients were assigned randomly to groups given diosmectite or placebo, in addition to oral rehydration solution (World Health Organization). Children in each study had comparable average ages and weights. The frequencies of rotavirus infection were 22% in Peru and 12% in Malaysia. Similar amounts of oral rehydration solution were given to children in the diosmectite and placebo groups. Stool output was decreased significantly by diosmectite in both studies, especially among rotavirus-positive children. In pooled data, children had a mean stool output of 94.5 +/- 74.4 g/kg of body weight in the diosmectite group versus 104.1 +/- 94.2 g/kg in the placebo group (P = .002). Diarrhea duration was reduced by diosmectite, which was well tolerated. These results show that diosmectite significantly decreased stool output in children with acute watery diarrhea, especially those who were rotavirus-positive.

  17. Stimulus-dependent maximum entropy models of neural population codes.

    Directory of Open Access Journals (Sweden)

    Einat Granot-Atedgi

    Full Text Available Neural populations encode information about their stimulus in a collective fashion, by joint activity patterns of spiking and silence. A full account of this mapping from stimulus to neural activity is given by the conditional probability distribution over neural codewords given the sensory input. For large populations, direct sampling of these distributions is impossible, and so we must rely on constructing appropriate models. We show here that in a population of 100 retinal ganglion cells in the salamander retina responding to temporal white-noise stimuli, dependencies between cells play an important encoding role. We introduce the stimulus-dependent maximum entropy (SDME model-a minimal extension of the canonical linear-nonlinear model of a single neuron, to a pairwise-coupled neural population. We find that the SDME model gives a more accurate account of single cell responses and in particular significantly outperforms uncoupled models in reproducing the distributions of population codewords emitted in response to a stimulus. We show how the SDME model, in conjunction with static maximum entropy models of population vocabulary, can be used to estimate information-theoretic quantities like average surprise and information transmission in a neural population.

  18. Does Black’s Hypothesis for Output Variability Hold for Mexico?

    OpenAIRE

    Macri, Joseph; Sinha, Dipendra

    2007-01-01

    Using two data series, namely GDP and the index of industrial production, we study the relationship between output variability and the growth rate of output. Ng-Perron unit root test shows that the growth rate of GDP is non-stationary but the growth rate of industrial output is stationary. Thus, we use the ARCH-M model for the monthly data of industrial output. A number of specifications (with and without a dummy variable) are used. In all cases, the results show that output variability has a...

  19. Evaluating lexical characteristics of verbal fluency output in schizophrenia.

    Science.gov (United States)

    Juhasz, Barbara J; Chambers, Destinee; Shesler, Leah W; Haber, Alix; Kurtz, Matthew M

    2012-12-30

    Standardized lexical analysis of verbal output has not been applied to verbal fluency tasks in schizophrenia. Performance of individuals with schizophrenia on both a letter (n=139) and semantic (n=137) fluency task was investigated. The lexical characteristics (word frequency, age-of-acquisition, word length, and semantic typicality) of words produced were evaluated and compared to those produced by a healthy control group matched on age, gender, and Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) vocabulary scores (n=20). Overall, individuals with schizophrenia produced fewer words than healthy controls, replicating past research (see Bokat and Goldberg, 2003). Words produced in the semantic fluency task by individuals with schizophrenia were, on average, earlier acquired and more typical of the category. In contrast, no differences in lexical characteristics emerged in the letter fluency task. The results are informative regarding how individuals with schizophrenia access their mental lexicons during the verbal fluency task. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  20. Global Sensitivity Analysis for multivariate output using Polynomial Chaos Expansion

    International Nuclear Information System (INIS)

    Garcia-Cabrejo, Oscar; Valocchi, Albert

    2014-01-01

    Many mathematical and computational models used in engineering produce multivariate output that shows some degree of correlation. However, conventional approaches to Global Sensitivity Analysis (GSA) assume that the output variable is scalar. These approaches are applied on each output variable leading to a large number of sensitivity indices that shows a high degree of redundancy making the interpretation of the results difficult. Two approaches have been proposed for GSA in the case of multivariate output: output decomposition approach [9] and covariance decomposition approach [14] but they are computationally intensive for most practical problems. In this paper, Polynomial Chaos Expansion (PCE) is used for an efficient GSA with multivariate output. The results indicate that PCE allows efficient estimation of the covariance matrix and GSA on the coefficients in the approach defined by Campbell et al. [9], and the development of analytical expressions for the multivariate sensitivity indices defined by Gamboa et al. [14]. - Highlights: • PCE increases computational efficiency in 2 approaches of GSA of multivariate output. • Efficient estimation of covariance matrix of output from coefficients of PCE. • Efficient GSA on coefficients of orthogonal decomposition of the output using PCE. • Analytical expressions of multivariate sensitivity indices from coefficients of PCE

  1. Maximum wind energy extraction strategies using power electronic converters

    Science.gov (United States)

    Wang, Quincy Qing

    2003-10-01

    This thesis focuses on maximum wind energy extraction strategies for achieving the highest energy output of variable speed wind turbine power generation systems. Power electronic converters and controls provide the basic platform to accomplish the research of this thesis in both hardware and software aspects. In order to send wind energy to a utility grid, a variable speed wind turbine requires a power electronic converter to convert a variable voltage variable frequency source into a fixed voltage fixed frequency supply. Generic single-phase and three-phase converter topologies, converter control methods for wind power generation, as well as the developed direct drive generator, are introduced in the thesis for establishing variable-speed wind energy conversion systems. Variable speed wind power generation system modeling and simulation are essential methods both for understanding the system behavior and for developing advanced system control strategies. Wind generation system components, including wind turbine, 1-phase IGBT inverter, 3-phase IGBT inverter, synchronous generator, and rectifier, are modeled in this thesis using MATLAB/SIMULINK. The simulation results have been verified by a commercial simulation software package, PSIM, and confirmed by field test results. Since the dynamic time constants for these individual models are much different, a creative approach has also been developed in this thesis to combine these models for entire wind power generation system simulation. An advanced maximum wind energy extraction strategy relies not only on proper system hardware design, but also on sophisticated software control algorithms. Based on literature review and computer simulation on wind turbine control algorithms, an intelligent maximum wind energy extraction control algorithm is proposed in this thesis. This algorithm has a unique on-line adaptation and optimization capability, which is able to achieve maximum wind energy conversion efficiency through

  2. LD-pumped actively Q-switched c-cut Nd:GdVO4 self-Raman laser operating at 1166 and 1176 nm

    Science.gov (United States)

    Sun, Xinzhi; Zhang, Xihe; Li, Shutao; Dong, Yuan

    2017-12-01

    A laser diode pumped actively Q-switched c-cut Nd:GdVO4 self-Raman laser is experimentally investigated. Simultaneous pulse outputs at 1166 nm and 1176 nm corresponding to the Raman shifts of 807 and 882 cm-1 are acquired. At the pulse repetition frequency (PRF) of 20 kHz, the maximum output power is 103 mW at 1166 nm with the incident pump power of 2.31 W, while 1176 nm output power reaches 530 mW with the incident pump power of 4.11 W. The maximum output power of Raman laser is 570 mW with the incident pump power of 4.11 W and the PRF of 30 kHz. With the incident pump power of 3.67 W and the PRF of 30 kHz, the highest diode-to-Stokes optical conversion efficiency of 14.9% is obtained with the corresponding average output power of 547 mW.

  3. A mesic maximum in biological water use demarcates biome sensitivity to aridity shifts.

    Science.gov (United States)

    Good, Stephen P; Moore, Georgianne W; Miralles, Diego G

    2017-12-01

    Biome function is largely governed by how efficiently available resources can be used and yet for water, the ratio of direct biological resource use (transpiration, E T ) to total supply (annual precipitation, P) at ecosystem scales remains poorly characterized. Here, we synthesize field, remote sensing and ecohydrological modelling estimates to show that the biological water use fraction (E T /P) reaches a maximum under mesic conditions; that is, when evaporative demand (potential evapotranspiration, E P ) slightly exceeds supplied precipitation. We estimate that this mesic maximum in E T /P occurs at an aridity index (defined as E P /P) between 1.3 and 1.9. The observed global average aridity of 1.8 falls within this range, suggesting that the biosphere is, on average, configured to transpire the largest possible fraction of global precipitation for the current climate. A unimodal E T /P distribution indicates that both dry regions subjected to increasing aridity and humid regions subjected to decreasing aridity will suffer declines in the fraction of precipitation that plants transpire for growth and metabolism. Given the uncertainties in the prediction of future biogeography, this framework provides a clear and concise determination of ecosystems' sensitivity to climatic shifts, as well as expected patterns in the amount of precipitation that ecosystems can effectively use.

  4. Watt-level ~2 μm laser output in Tm3+-doped tungsten tellurite glass double-cladding fiber.

    Science.gov (United States)

    Li, Kefeng; Zhang, Guang; Hu, Lili

    2010-12-15

    We report, for the first time to the best of our knowledge, a watt level cw fiber laser at ~2 μm from a piece of 40-cm-long newly developed highly thulium-doped (3.76 × 10(20) ions/cm(3)) tungsten tellurite glass double cladding fiber pumped by a commercial 800 nm laser diode. The maximum output power of the fiber laser reaches 1.12 W. The slope efficiency and the optical-optical efficiency with respect to the absorbed pump are 20% and 16%, respectively. The lasing threshold is 1.46 W, and the lasing wavelength is centered at 1937 nm.

  5. Nine Criteria for a Measure of Scientific Output

    Science.gov (United States)

    Kreiman, Gabriel; Maunsell, John H. R.

    2011-01-01

    Scientific research produces new knowledge, technologies, and clinical treatments that can lead to enormous returns. Often, the path from basic research to new paradigms and direct impact on society takes time. Precise quantification of scientific output in the short-term is not an easy task but is critical for evaluating scientists, laboratories, departments, and institutions. While there have been attempts to quantifying scientific output, we argue that current methods are not ideal and suffer from solvable difficulties. Here we propose criteria that a metric should have to be considered a good index of scientific output. Specifically, we argue that such an index should be quantitative, based on robust data, rapidly updated and retrospective, presented with confidence intervals, normalized by number of contributors, career stage and discipline, impractical to manipulate, and focused on quality over quantity. Such an index should be validated through empirical testing. The purpose of quantitatively evaluating scientific output is not to replace careful, rigorous review by experts but rather to complement those efforts. Because it has the potential to greatly influence the efficiency of scientific research, we have a duty to reflect upon and implement novel and rigorous ways of evaluating scientific output. The criteria proposed here provide initial steps toward the systematic development and validation of a metric to evaluate scientific output. PMID:22102840

  6. Multiple output timing and trigger generator

    Energy Technology Data Exchange (ETDEWEB)

    Wheat, Robert M. [Los Alamos National Laboratory; Dale, Gregory E [Los Alamos National Laboratory

    2009-01-01

    In support of the development of a multiple stage pulse modulator at the Los Alamos National Laboratory, we have developed a first generation, multiple output timing and trigger generator. Exploiting Commercial Off The Shelf (COTS) Micro Controller Units (MCU's), the timing and trigger generator provides 32 independent outputs with a timing resolution of about 500 ns. The timing and trigger generator system is comprised of two MCU boards and a single PC. One of the MCU boards performs the functions of the timing and signal generation (the timing controller) while the second MCU board accepts commands from the PC and provides the timing instructions to the timing controller. The PC provides the user interface for adjusting the on and off timing for each of the output signals. This system provides 32 output or timing signals which can be pre-programmed to be in an on or off state for each of 64 time steps. The width or duration of each of the 64 time steps is programmable from 2 {micro}s to 2.5 ms with a minimum time resolution of 500 ns. The repetition rate of the programmed pulse train is only limited by the time duration of the programmed event. This paper describes the design and function of the timing and trigger generator system and software including test results and measurements.

  7. The multi-factor energy input–output model

    International Nuclear Information System (INIS)

    Guevara, Zeus; Domingos, Tiago

    2017-01-01

    Energy input–output analysis (EIO analysis) is a noteworthy tool for the analysis of the role of energy in the economy. However, it has relied on models that provide a limited description of energy flows in the economic system and do not allow an adequate analysis of energy efficiency. This paper introduces a novel energy input–output model, the multi-factor energy input–output model (MF-EIO model), which is obtained from a partitioning of a hybrid-unit input–output system of the economy. This model improves on current models by describing the energy flows according to the processes of energy conversion and the levels of energy use in the economy. It characterizes the vector of total energy output as a function of seven factors: two energy efficiency indicators; two characteristics of end-use energy consumption; and three economic features of the rest of the economy. Moreover, it is consistent with the standard model for EIO analysis, i.e., the hybrid-unit model. This paper also introduces an approximate version of the MF-EIO model, which is equivalent to the former under equal energy prices for industries and final consumers, but requires less data processing. The latter is composed by two linked models: a model of the energy sector in physical units, and a model of the rest of the economy in monetary units. In conclusion, the proposed modelling framework improves EIO analysis and extends EIO applications to the accounting for energy efficiency of the economy. - Highlights: • A novel energy input–output model is introduced. • It allows a more adequate analysis of energy flows than current models. • It describes energy flows according to processes of energy conversion and use. • It can be used for other environmental applications (material use and emissions). • An approximate version of the model is introduced, simpler and less data intensive.

  8. Numerical and experimental research on pentagonal cross-section of the averaging Pitot tube

    International Nuclear Information System (INIS)

    Zhang, Jili; Li, Wei; Liang, Ruobing; Zhao, Tianyi; Liu, Yacheng; Liu, Mingsheng

    2017-01-01

    Averaging Pitot tubes have been widely used in many fields because of their simple structure and stable performance. This paper introduces a new shape of the cross-section of an averaging Pitot tube. Firstly, the structure of the averaging Pitot tube and the distribution of pressure taps are given. Then, a mathematical model of the airflow around it is formulated. After that, a series of numerical simulations are carried out to optimize the geometry of the tube. The distribution of the streamline and pressures around the tube are given. To test its performance, a test platform was constructed in accordance with the relevant national standards and is described in this paper. Curves are provided, linking the values of flow coefficient with the values of Reynolds number. With a maximum deviation of only  ±3%, the results of the flow coefficient obtained from the numerical simulations were in agreement with those obtained from experimental methods. The proposed tube has a stable flow coefficient and favorable metrological characteristics. (paper)

  9. Output blue light evaluation for phosphor based smart white LED wafer level packages.

    Science.gov (United States)

    Kolahdouz, Zahra; Rostamian, Ali; Kolahdouz, Mohammadreza; Ma, Teng; van Zeijl, Henk; Zhang, Kouchi

    2016-02-22

    This study presents a blue light detector for evaluating the output light of phosphor based white LED package. It is composed of a silicon stripe-shaped photodiode designed and implemented in a 2 μm BiCMOS process which can be used for wafer level integration of different passive and active devices all in just 5 lithography steps. The final device shows a high selectivity to blue light. The maximum responsivity at 480 nm is matched with the target blue LED illumination. The designed structure have better responsivity compared to simple photodiode structure due to reducing the effect of dead layer formation close to the surface because of implantation. It has also a two-fold increase in the responsivity and quantum efficiency compared to previously similar published sensors.

  10. A PPM-focused klystron at X-band with a traveling-wave output structure

    International Nuclear Information System (INIS)

    Eppley, K.R.

    1995-01-01

    We have developed algorithms for designing disk-loaded traveling-wave output structures for X-band klystrons to be used in the SLAC NLC. We use either a four- or five-cell structure in a π/2 mode. The disk radii are tapered to produce an approximately constant gradient. The matching calculation is not performed on the tapered structure, but rather on a coupler whose input and output cells are the same as the final cell of the tapered structure, and whose interior cells are the same as the penultimate cell in the tapered structure. 2-D calculations using CONDOR model the waveguide as a radial transmission line of adjustable impedance. 3-D calculations with MAFIA model the actual rectangular waveguide and coupling slot. A good match is obtained by adjusting the impedance of the final cell. In 3-D, this requires varying both the radius of the cell and the width of the aperture. When the output cell with the best match is inserted in the tapered structure, we obtain excellent cold-test agreement between the 2-D and 3-D models. We use hot-test simulations with CONDOR to design a structure with maximum efficiency and minimum surface fields. We have designed circuits at 11.424 Ghz for different perveances. At 440 kV, microperveance 1.2, we calculated 81 MW, 53 percent efficiency, with peak surface field 76 MV/m. A microperveance 0.6 design was done using a PPM stack for focusing. At 470 kV, 193 amps, we calculated 58.7 MW, 64.7 percent efficiency, peak surface field 62.3 MV/m. At 500 kV, 212 amps, we calculated 67.1 MW, 63.3 percent efficiency, peak surface field 66.0 MV/m. copyright 1995 American Institute of Physics

  11. Reducing variability in the output of pattern classifiers using histogram shaping

    International Nuclear Information System (INIS)

    Gupta, Shalini; Kan, Chih-Wen; Markey, Mia K.

    2010-01-01

    Purpose: The authors present a novel technique based on histogram shaping to reduce the variability in the output and (sensitivity, specificity) pairs of pattern classifiers with identical ROC curves, but differently distributed outputs. Methods: The authors identify different sources of variability in the output of linear pattern classifiers with identical ROC curves, which also result in classifiers with differently distributed outputs. They theoretically develop a novel technique based on the matching of the histograms of these differently distributed pattern classifier outputs to reduce the variability in their (sensitivity, specificity) pairs at fixed decision thresholds, and to reduce the variability in their actual output values. They empirically demonstrate the efficacy of the proposed technique by means of analyses on the simulated data and real world mammography data. Results: For the simulated data, with three different known sources of variability, and for the real world mammography data with unknown sources of variability, the proposed classifier output calibration technique significantly reduced the variability in the classifiers' (sensitivity, specificity) pairs at fixed decision thresholds. Furthermore, for classifiers with monotonically or approximately monotonically related output variables, the histogram shaping technique also significantly reduced the variability in their actual output values. Conclusions: Classifier output calibration based on histogram shaping can be successfully employed to reduce the variability in the output values and (sensitivity, specificity) pairs of pattern classifiers with identical ROC curves, but differently distributed outputs.

  12. Chronic resuscitation after trauma-hemorrhage and acute fluid replacement improves hepatocellular function and cardiac output.

    Science.gov (United States)

    Remmers, D E; Wang, P; Cioffi, W G; Bland, K I; Chaudry, I H

    1998-01-01

    To determine whether prolonged (chronic) resuscitation has any beneficial effects on cardiac output and hepatocellular function after trauma-hemorrhage and acute fluid replacement. Acute fluid resuscitation after trauma-hemorrhage restores but does not maintain the depressed hepatocellular function and cardiac output. Male Sprague-Dawley rats underwent a 5-cm laparotomy (i.e., trauma was induced) and were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of maximal bleed-out volume was returned in the form of Ringer's lactate (RL). The animals were acutely resuscitated with RL using 4 times the volume of maximum bleed-out over 60 minutes, followed by chronic resuscitation of 0, 5, or 10 mL/kg/hr RL for 20 hours. Hepatocellular function was determined by an in vivo indocyanine green clearance technique. Hepatic microvascular blood flow was assessed by laser Doppler flowmetry. Plasma levels of interleukin-6 (IL-6) were determined by bioassay. Chronic resuscitation with 5 mL/kg/hr RL, but not with 0 or 10 mL/kg/hr RL, restored cardiac output, hepatocellular function, and hepatic microvascular blood flow at 20 hours after hemorrhage. The regimen above also reduced plasma IL-6 levels. Because chronic resuscitation with 5 mL/kg/hr RL after trauma-hemorrhage and acute fluid replacement restored hepatocellular function and hepatic microvascular blood flow and decreased plasma levels of IL-6, we propose that chronic fluid resuscitation in addition to acute fluid replacement should be routinely used in experimental studies of trauma-hemorrhage.

  13. Using net energy output as the base to develop renewable energy

    International Nuclear Information System (INIS)

    Shaw Daigee; Hung Mingfeng; Lin Yihao

    2010-01-01

    In order to increase energy security, production of renewable energies has been highly promoted by governments around the world in recent years. The typical base of various policy instruments used for this purpose is gross energy output of renewable energy. However, we show that basing policy instruments on gross energy output will result in problems associated with energy waste, economic inefficiency, and negative environmental effects. We recommend using net energy output as the base to apply price or quantity measures because it is net energy output, not gross energy output, which contributes to energy security. The promotion of gross energy output does not guarantee a positive amount of net energy output. By basing policy instruments on net energy output, energy security can be enhanced and the above mentioned problems can be avoided.

  14. UFO - The Universal FEYNRULES Output

    Science.gov (United States)

    Degrande, Céline; Duhr, Claude; Fuks, Benjamin; Grellscheid, David; Mattelaer, Olivier; Reiter, Thomas

    2012-06-01

    We present a new model format for automatized matrix-element generators, the so-called Universal FEYNRULES Output (UFO). The format is universal in the sense that it features compatibility with more than one single generator and is designed to be flexible, modular and agnostic of any assumption such as the number of particles or the color and Lorentz structures appearing in the interaction vertices. Unlike other model formats where text files need to be parsed, the information on the model is encoded into a PYTHON module that can easily be linked to other computer codes. We then describe an interface for the MATHEMATICA package FEYNRULES that allows for an automatic output of models in the UFO format.

  15. A multi-centre analysis of radiotherapy beam output measurement

    Directory of Open Access Journals (Sweden)

    Matthew A. Bolt

    2017-10-01

    Conclusions: Machine beam output measurements were largely within ±2% of 1.00 cGy/MU. Clear trends in measured output over time were seen, with some machines having large drifts which would result in additional burden to maintain within acceptable tolerances. This work may act as a baseline for future comparison of beam output measurements.

  16. Cooled solar PV panels for output energy efficiency optimisation

    International Nuclear Information System (INIS)

    Peng, Zhijun; Herfatmanesh, Mohammad R.; Liu, Yiming

    2017-01-01

    Highlights: • Effects of cooling on solar PV performance have been experimentally investigated. • As a solar panel is cooled down, the electric output can have significant increase. • A cooled solar PV system has been proposed for resident application. • Life cycle assessment suggests the cost payback time of cooled PV can be reduced. - Abstract: As working temperature plays a critical role in influencing solar PV’s electrical output and efficacy, it is necessary to examine possible way for maintaining the appropriate temperature for solar panels. This research is aiming to investigate practical effects of solar PV surface temperature on output performance, in particular efficiency. Experimental works were carried out under different radiation condition for exploring the variation of the output voltage, current, output power and efficiency. After that, the cooling test was conducted to find how much efficiency improvement can be achieved with the cooling condition. As test results show the efficiency of solar PV can have an increasing rate of 47% with the cooled condition, a cooling system is proposed for possible system setup of residential solar PV application. The system performance and life cycle assessment suggest that the annual PV electric output efficiencies can increase up to 35%, and the annual total system energy efficiency including electric output and hot water energy output can increase up to 107%. The cost payback time can be reduced to 12.1 years, compared to 15 years of the baseline of a similar system without cooling sub-system.

  17. Development of measurement device for evaluation of solar cell module output. 2; Taiyo denchi module shutsuryoku hyokayo sokuteiki no kaihatsu. 2

    Energy Technology Data Exchange (ETDEWEB)

    Minoda, M.; Itsumi, J. [Kumamoto Institute of Technology, Kumamoto (Japan)

    1996-10-27

    Enhancement in design efficiency may be attained as well as utilization in maintenance if on-the-spot data is made available, for the purpose of flexibly dealing with changes in design or matching with a house structure, in calculating the power generation output of a solar cell (PV) module. Under the circumstances, a small-sized compound measuring device was produced as a prototype which, using an I-V curve tracer, measured output and condition of a roof at the time of installation, compared with the optimum operation and predicted the power generation. The device was structured with the main body consisting of a computing part, measurement controller and power supply and with various sensor modules. The electron load control method was employed in order to measure I-V characteristics of the PV module, since it was desirable to use a variable load and to cover the range from the release voltage of a solar cell to the short-circuit state through the maximum output point. The reference module method was used for the system evaluation. The device was presumably applicable to a PV system design by incorporating a sensor module for measuring design environment data, which was essential at the time of a system design, in addition to those for measuring output. 9 refs., 4 figs., 3 tabs.

  18. Hybrid optoelectronic device with multiple bistable outputs

    Energy Technology Data Exchange (ETDEWEB)

    Costazo-Caso, Pablo A; Jin Yiye; Gelh, Michael; Granieri, Sergio; Siahmakoun, Azad, E-mail: pcostanzo@ing.unlp.edu.are, E-mail: granieri@rose-hulma.edu, E-mail: siahmako@rose-hulma.edu [Department of Physics and Optical Engineering, Rose-Hulman Institute of Technology, 5500 Wabash Avenue, Terre Haute, IN 47803 (United States)

    2011-01-01

    Optoelectronic circuits which exhibit optical and electrical bistability with hysteresis behavior are proposed and experimentally demonstrated. The systems are based on semiconductor optical amplifiers (SOA), bipolar junction transistors (BJT), PIN photodiodes (PD) and laser diodes externally modulated with integrated electro-absorption modulators (LD-EAM). The device operates based on two independent phenomena leading to both electrical bistability and optical bistability. The electrical bistability is due to the series connection of two p-i-n structures (SOA, BJT, PD or LD) in reverse bias. The optical bistability is consequence of the quantum confined Stark effect (QCSE) in the multi-quantum well (MQW) structure in the intrinsic region of the device. This effect produces the optical modulation of the transmitted light through the SOA (or reflected from the PD). Finally, because the optical transmission of the SOA (in reverse bias) and the reflected light from the PD are so small, a LD-EAM modulated by the voltage across these devices are employed to obtain a higher output optical power. Experiments show that the maximum switching frequency is in MHz range and the rise/fall times lower than 1 us. The temporal response is mainly limited by the electrical capacitance of the devices and the parasitic inductances of the connecting wires. The effects of these components can be reduced in current integration technologies.

  19. Design of a high average-power FEL driven by an existing 20 MV electrostatic-accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kimel, I.; Elias, L.R. [Univ. of Central Florida, Orlando, FL (United States)

    1995-12-31

    There are some important applications where high average-power radiation is required. Two examples are industrial machining and space power-beaming. Unfortunately, up to date no FEL has been able to show more than 10 Watts of average power. To remedy this situation we started a program geared towards the development of high average-power FELs. As a first step we are building in our CREOL laboratory, a compact FEL which will generate close to 1 kW in CW operation. As the next step we are also engaged in the design of a much higher average-power system based on a 20 MV electrostatic accelerator. This FEL will be capable of operating CW with a power output of 60 kW. The idea is to perform a high power demonstration using the existing 20 MV electrostatic accelerator at the Tandar facility in Buenos Aires. This machine has been dedicated to accelerate heavy ions for experiments and applications in nuclear and atomic physics. The necessary adaptations required to utilize the machine to accelerate electrons will be described. An important aspect of the design of the 20 MV system, is the electron beam optics through almost 30 meters of accelerating and decelerating tubes as well as the undulator. Of equal importance is a careful design of the long resonator with mirrors able to withstand high power loading with proper heat dissipation features.

  20. Analysis of photosynthate translocation velocity and measurement of weighted average velocity in transporting pathway of crops

    International Nuclear Information System (INIS)

    Ge Cailin; Luo Shishi; Gong Jian; Zhang Hao; Ma Fei

    1996-08-01

    The translocation profile pattern of 14 C-photosynthate along the transporting pathway in crops were monitored by pulse-labelling a mature leaf with 14 CO 2 . The progressive spreading of translocation profile pattern along the sheath or stem indicates that the translocation of photosynthate along the sheath or stem proceed with a range of velocities rather than with just a single velocity. The method for measuring the weighted average velocity of photosynthate translocation along the sheath or stem was established in living crops. The weighted average velocity and the maximum velocity of photosynthate translocation along the sheath in rice and maize were measured actually. (4 figs., 3 tabs.)

  1. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  2. Remote input/output station

    CERN Multimedia

    1972-01-01

    A general view of the remote input/output station installed in building 112 (ISR) and used for submitting jobs to the CDC 6500 and 6600. The card reader on the left and the line printer on the right are operated by programmers on a self-service basis.

  3. NGA-West 2 GMPE average site coefficients for use in earthquake-resistant design

    Science.gov (United States)

    Borcherdt, Roger D.

    2015-01-01

    Site coefficients corresponding to those in tables 11.4–1 and 11.4–2 of Minimum Design Loads for Buildings and Other Structures published by the American Society of Civil Engineers (Standard ASCE/SEI 7-10) are derived from four of the Next Generation Attenuation West2 (NGA-W2) Ground-Motion Prediction Equations (GMPEs). The resulting coefficients are compared with those derived by other researchers and those derived from the NGA-West1 database. The derivation of the NGA-W2 average site coefficients provides a simple procedure to update site coefficients with each update in the Maximum Considered Earthquake Response MCER maps. The simple procedure yields average site coefficients consistent with those derived for site-specific design purposes. The NGA-W2 GMPEs provide simple scale factors to reduce conservatism in current simplified design procedures.

  4. Output-based allocation and investment in clean technologies

    Energy Technology Data Exchange (ETDEWEB)

    Rosendahl, Knut Einar; Storroesten, Halvor Briseid

    2011-07-01

    Allocation of emission allowances may affect firms' incentives to invest in clean technologies. In this paper we show that so-called output-based allocation tends to stimulate such investments as long as individual firms do not assume the regulator to tighten the allocation rule as a consequence of their investments. The explanation is that output-based allocation creates an implicit subsidy to the firms' output, which increases production, leads to a higher price of allowances, and thus increases the incentives to invest in clean technologies. On the other hand, if the firms expect the regulator to tighten the allocation rule after observing their clean technology investment, the firms' incentives to invest are moderated. If strong, this last effect may outweigh the enhanced investment incentives induced by increased output and higher allowance price. (Author)

  5. Finite-time output feedback stabilization of high-order uncertain nonlinear systems

    Science.gov (United States)

    Jiang, Meng-Meng; Xie, Xue-Jun; Zhang, Kemei

    2018-06-01

    This paper studies the problem of finite-time output feedback stabilization for a class of high-order nonlinear systems with the unknown output function and control coefficients. Under the weaker assumption that output function is only continuous, by using homogeneous domination method together with adding a power integrator method, introducing a new analysis method, the maximal open sector Ω of output function is given. As long as output function belongs to any closed sector included in Ω, an output feedback controller can be developed to guarantee global finite-time stability of the closed-loop system.

  6. Maximum photovoltaic power tracking for the PV array using the fractional-order incremental conductance method

    International Nuclear Information System (INIS)

    Lin, Chia-Hung; Huang, Cong-Hui; Du, Yi-Chun; Chen, Jian-Liung

    2011-01-01

    Highlights: → The FOICM can shorten the tracking time less than traditional methods. → The proposed method can work under lower solar radiation including thin and heavy clouds. → The FOICM algorithm can achieve MPPT for radiation and temperature changes. → It is easy to implement in a single-chip microcontroller or embedded system. -- Abstract: This paper proposes maximum photovoltaic power tracking (MPPT) for the photovoltaic (PV) array using the fractional-order incremental conductance method (FOICM). Since the PV array has low conversion efficiency, and the output power of PV array depends on the operation environments, such as various solar radiation, environment temperature, and weather conditions. Maximum charging power can be increased to a battery using a MPPT algorithm. The energy conversion of the absorbed solar light and cell temperature is directly transferred to the semiconductor, but electricity conduction has anomalous diffusion phenomena in inhomogeneous material. FOICM can provide a dynamic mathematical model to describe non-linear characteristics. The fractional-order incremental change as dynamic variable is used to adjust the PV array voltage toward the maximum power point. For a small-scale PV conversion system, the proposed method is validated by simulation with different operation environments. Compared with traditional methods, experimental results demonstrate the short tracking time and the practicality in MPPT of PV array.

  7. Mode-locked Ti:sapphire laser oscillators pumped by wavelength-multiplexed laser diodes

    Science.gov (United States)

    Sugiyama, Naoto; Tanaka, Hiroki; Kannari, Fumihiko

    2018-05-01

    We directly pumped a Ti:sapphire laser by combining 478 and 520 nm laser diodes to prevent the effect of absorption loss induced by the pump laser of shorter wavelengths (∼450 nm). We obtain a continuous-wave output power of 660 mW at a total incident pump power of 3.15 W. We demonstrate mode locking using a semiconductor saturable absorber mirror, and 126 fs pulses were obtained at a repetition rate of 192 MHz. At the maximum pump power, the average output power is 315 mW. Shorter mode-locked pulses of 42 and 48 fs were respectively achieved by Kerr-lens mode locking with average output powers of 280 and 360 mW at a repetition rate of 117 MHz.

  8. A 240W Monolithic Class-D Audio Amplifier Output Stage

    OpenAIRE

    Nyboe, Flemming; Kaya, Cetin; Risbo, Lars; Andreani, Pietro

    2006-01-01

    A single-channel class-D audio amplifier output stage outputs 240W undipped into 4Omega 0.1% open-loop THD+N allows using the device in a fully-digital audio signal path with no feedback. The output current capability is plusmn18A and the part is fabricated in a 0.4mum/1.8mum high-voltage BiCMOS process. Over-current sensing protects the output from short circuits.

  9. Maximum And Minimum Temperature Trends In Mexico For The Last 31 Years

    Science.gov (United States)

    Romero-Centeno, R.; Zavala-Hidalgo, J.; Allende Arandia, M. E.; Carrasco-Mijarez, N.; Calderon-Bustamante, O.

    2013-05-01

    Based on high-resolution (1') daily maps of the maximum and minimum temperatures in Mexico, an analysis of the last 31-year trends is performed. The maps were generated using all the available information from more than 5,000 stations of the Mexican Weather Service (Servicio Meteorológico Nacional, SMN) for the period 1979-2009, along with data from the North American Regional Reanalysis (NARR). The data processing procedure includes a quality control step, in order to eliminate erroneous daily data, and make use of a high-resolution digital elevation model (from GEBCO), the relationship between air temperature and elevation by means of the average environmental lapse rate, and interpolation algorithms (linear and inverse-distance weighting). Based on the monthly gridded maps for the mentioned period, the maximum and minimum temperature trends calculated by least-squares linear regression and their statistical significance are obtained and discussed.

  10. Five-way smoking status classification using text hot-spot identification and error-correcting output codes.

    Science.gov (United States)

    Cohen, Aaron M

    2008-01-01

    We participated in the i2b2 smoking status classification challenge task. The purpose of this task was to evaluate the ability of systems to automatically identify patient smoking status from discharge summaries. Our submission included several techniques that we compared and studied, including hot-spot identification, zero-vector filtering, inverse class frequency weighting, error-correcting output codes, and post-processing rules. We evaluated our approaches using the same methods as the i2b2 task organizers, using micro- and macro-averaged F1 as the primary performance metric. Our best performing system achieved a micro-F1 of 0.9000 on the test collection, equivalent to the best performing system submitted to the i2b2 challenge. Hot-spot identification, zero-vector filtering, classifier weighting, and error correcting output coding contributed additively to increased performance, with hot-spot identification having by far the largest positive effect. High performance on automatic identification of patient smoking status from discharge summaries is achievable with the efficient and straightforward machine learning techniques studied here.

  11. The light output of BGO crystals

    International Nuclear Information System (INIS)

    Gong Zhufang; Ma Wengan; Lin Zhirong; Wang Zhaomin; Xu Zhizong; Fan Yangmei

    1987-01-01

    The dependence of light output on the surface treatment of BGO crystals has been tested. The results of experiments and Monte Carlo calculation indicate that for a tapered BGO crystal the best way to improve the uniformity and the energy resolution and to obtain higher light output is roughing the surface coupled to photomultiplier tube. The authors also observed that different wrapping method can effect its uniformity and resolutoin. Monte Carlo calculation indicates that the higher one of the 'double peaks' is the photoelectron peak of γ rays

  12. Correction of measured Gamma-Knife output factors for angular dependence of diode detectors and PinPoint ionization chamber.

    Science.gov (United States)

    Hršak, Hrvoje; Majer, Marija; Grego, Timor; Bibić, Juraj; Heinrich, Zdravko

    2014-12-01

    Dosimetry for Gamma-Knife requires detectors with high spatial resolution and minimal angular dependence of response. Angular dependence and end effect time for p-type silicon detectors (PTW Diode P and Diode E) and PTW PinPoint ionization chamber were measured with Gamma-Knife beams. Weighted angular dependence correction factors were calculated for each detector. The Gamma-Knife output factors were corrected for angular dependence and end effect time. For Gamma-Knife beams angle range of 84°-54°. Diode P shows considerable angular dependence of 9% and 8% for the 18 mm and 14, 8, 4 mm collimator, respectively. For Diode E this dependence is about 4% for all collimators. PinPoint ionization chamber shows angular dependence of less than 3% for 18, 14 and 8 mm helmet and 10% for 4 mm collimator due to volumetric averaging effect in a small photon beam. Corrected output factors for 14 mm helmet are in very good agreement (within ±0.3%) with published data and values recommended by vendor (Elekta AB, Stockholm, Sweden). For the 8 mm collimator diodes are still in good agreement with recommended values (within ±0.6%), while PinPoint gives 3% less value. For the 4 mm helmet Diodes P and E show over-response of 2.8% and 1.8%, respectively. For PinPoint chamber output factor of 4 mm collimator is 25% lower than Elekta value which is generally not consequence of angular dependence, but of volumetric averaging effect and lack of lateral electronic equilibrium. Diodes P and E represent good choice for Gamma-Knife dosimetry. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. Inflation, inflation uncertainty and output growth in the USA

    Science.gov (United States)

    Bhar, Ramprasad; Mallik, Girijasankar

    2010-12-01

    Employing a multivariate EGARCH-M model, this study investigates the effects of inflation uncertainty and growth uncertainty on inflation and output growth in the United States. Our results show that inflation uncertainty has a positive and significant effect on the level of inflation and a negative and significant effect on the output growth. However, output uncertainty has no significant effect on output growth or inflation. The oil price also has a positive and significant effect on inflation. These findings are robust and have been corroborated by use of an impulse response function. These results have important implications for inflation-targeting monetary policy, and the aim of stabilization policy in general.

  14. Focused information criterion and model averaging based on weighted composite quantile regression

    KAUST Repository

    Xu, Ganggang

    2013-08-13

    We study the focused information criterion and frequentist model averaging and their application to post-model-selection inference for weighted composite quantile regression (WCQR) in the context of the additive partial linear models. With the non-parametric functions approximated by polynomial splines, we show that, under certain conditions, the asymptotic distribution of the frequentist model averaging WCQR-estimator of a focused parameter is a non-linear mixture of normal distributions. This asymptotic distribution is used to construct confidence intervals that achieve the nominal coverage probability. With properly chosen weights, the focused information criterion based WCQR estimators are not only robust to outliers and non-normal residuals but also can achieve efficiency close to the maximum likelihood estimator, without assuming the true error distribution. Simulation studies and a real data analysis are used to illustrate the effectiveness of the proposed procedure. © 2013 Board of the Foundation of the Scandinavian Journal of Statistics..

  15. Extending the input–output energy balance methodology in agriculture through cluster analysis

    International Nuclear Information System (INIS)

    Bojacá, Carlos Ricardo; Casilimas, Héctor Albeiro; Gil, Rodrigo; Schrevens, Eddie

    2012-01-01

    The input–output balance methodology has been applied to characterize the energy balance of agricultural systems. This study proposes to extend this methodology with the inclusion of multivariate analysis to reveal particular patterns in the energy use of a system. The objective was to demonstrate the usefulness of multivariate exploratory techniques to analyze the variability found in a farming system and, establish efficiency categories that can be used to improve the energy balance of the system. To this purpose an input–output analysis was applied to the major greenhouse tomato production area in Colombia. Individual energy profiles were built and the k-means clustering method was applied to the production factors. On average, the production system in the study zone consumes 141.8 GJ ha −1 to produce 96.4 GJ ha −1 , resulting in an energy efficiency of 0.68. With the k-means clustering analysis, three clusters of farmers were identified with energy efficiencies of 0.54, 0.67 and 0.78. The most energy efficient cluster grouped 56.3% of the farmers. It is possible to optimize the production system by improving the management practices of those with the lowest energy use efficiencies. Multivariate analysis techniques demonstrated to be a complementary pathway to improve the energy efficiency of a system. -- Highlights: ► An input–output energy balance was estimated for greenhouse tomatoes in Colombia. ► We used the k-means clustering method to classify growers based on their energy use. ► Three clusters of growers were found with energy efficiencies of 0.54, 0.67 and 0.78. ► Overall system optimization is possible by improving the energy use of the less efficient.

  16. Breast cancer research output, 1945-2008: a bibliometric and density-equalizing analysis.

    Science.gov (United States)

    Glynn, Ronan W; Scutaru, Cristian; Kerin, Michael J; Sweeney, Karl J

    2010-01-01

    Breast cancer is the most common form of cancer among women, with an estimated 194,280 new cases diagnosed in the United States in 2009 alone. The primary aim of this work was to provide an in-depth evaluation of research yield in breast cancer from 1945 to 2008, using large-scale data analysis, the employment of bibliometric indicators of production and quality, and density-equalizing mapping. Data were retrieved from the Web of Science (WOS) Science Citation Expanded database; this was searched using the Boolean operator, 'OR', with different terms related to breast cancer, including "breast cancer", "mammary ductal carcinoma" and "breast tumour". Data were then extracted from each file, transferred to Excel charts and visualised as diagrams. Mapping was performed as described by Groneberg-Kloft et al. in 2008. A total of 180,126 breast cancer-associated items were produced over the study period; these had been cited 4,136,224 times. The United States returned the greatest level of output (n = 77,101), followed by the UK (n = 18,357) and Germany (n = 12,529). International cooperation peaked in 2008, with 3,127 entries produced as a result; relationships between the United States and other countries formed the basis for the 10 most common forms of bilateral cooperation. Publications from nations with high levels of international cooperation were associated with greater average citation rates. A total of 4,096 journals published at least one item on breast cancer, although the top 50 most prolific titles together accounted for over 43% (77,517/180,126) of the total output. Breast cancer-associated research output continues to increase annually. In an era when bibliometric indicators are increasingly being employed in performance assessment, these findings should provide useful information for those tasked with improving that performance.

  17. ARMA-Based SEM When the Number of Time Points T Exceeds the Number of Cases N: Raw Data Maximum Likelihood.

    Science.gov (United States)

    Hamaker, Ellen L.; Dolan, Conor V.; Molenaar, Peter C. M.

    2003-01-01

    Demonstrated, through simulation, that stationary autoregressive moving average (ARMA) models may be fitted readily when T>N, using normal theory raw maximum likelihood structural equation modeling. Also provides some illustrations based on real data. (SLD)

  18. Study on the output factors of asymmetrical rectangular electron beam field

    International Nuclear Information System (INIS)

    Chen Yinghai; Yang Yueqin; Ma Yuhong; Zheng Jin; Zou Lijuan

    2009-01-01

    Objective: To evaluate the variant regularity of the output factors of asymmetrical rectangular electron beam field. Methods: The output factors of three special fields with different applicators and energies were measured by ionization chamber method at different off-axis distances. Then deviations of the output factors between asymmetrical and symmetric rectangular fields were calculated. Results: The changes of output factor with different off-axis distances in asymmetrical rectangular fields were basically consistent with those in standard square fields with the same applicator. It revealed that the output factor of asymmetrical rectangular field was related with the off-axis ratio of standard square field. Applicator and field size did not show obvious influence on the output factor. Conclusions: The output factor changes of asymmetrical rectangular field are mainly correlated with the off-axis ratio of standard square field. The correction of the output factor is determined by the off-axis ratio changes in standard square field. (authors)

  19. Effects of Measurement Error on the Output Gap in Japan

    OpenAIRE

    Koichiro Kamada; Kazuto Masuda

    2000-01-01

    Potential output is the largest amount of products that can be produced by fully utilizing available labor and capital stock; the output gap is defined as the discrepancy between actual and potential output. If data on production factors contain measurement errors, total factor productivity (TFP) cannot be estimated accurately from the Solow residual(i.e., the portion of output that is not attributable to labor and capital inputs). This may give rise to distortions in the estimation of potent...

  20. Minimal models of multidimensional computations.

    Directory of Open Access Journals (Sweden)

    Jeffrey D Fitzgerald

    2011-03-01

    Full Text Available The multidimensional computations performed by many biological systems are often characterized with limited information about the correlations between inputs and outputs. Given this limitation, our approach is to construct the maximum noise entropy response function of the system, leading to a closed-form and minimally biased model consistent with a given set of constraints on the input/output moments; the result is equivalent to conditional random field models from machine learning. For systems with binary outputs, such as neurons encoding sensory stimuli, the maximum noise entropy models are logistic functions whose arguments depend on the constraints. A constraint on the average output turns the binary maximum noise entropy models into minimum mutual information models, allowing for the calculation of the information content of the constraints and an information theoretic characterization of the system's computations. We use this approach to analyze the nonlinear input/output functions in macaque retina and thalamus; although these systems have been previously shown to be responsive to two input dimensions, the functional form of the response function in this reduced space had not been unambiguously identified. A second order model based on the logistic function is found to be both necessary and sufficient to accurately describe the neural responses to naturalistic stimuli, accounting for an average of 93% of the mutual information with a small number of parameters. Thus, despite the fact that the stimulus is highly non-Gaussian, the vast majority of the information in the neural responses is related to first and second order correlations. Our results suggest a principled and unbiased way to model multidimensional computations and determine the statistics of the inputs that are being encoded in the outputs.