WorldWideScience

Sample records for direct gain systems

  1. Directional amplifier in an optomechanical system with optical gain

    Science.gov (United States)

    Jiang, Cheng; Song, L. N.; Li, Yong

    2018-05-01

    Directional amplifiers are crucial nonreciprocal devices in both classical and quantum information processing. Here we propose a scheme for realizing a directional amplifier between optical and microwave fields based on an optomechanical system with optical gain, where an active optical cavity and two passive microwave cavities are coupled to a common mechanical resonator via radiation pressure. The two passive cavities are coupled via hopping interaction to facilitate the directional amplification between the active and passive cavities. We obtain the condition of achieving optical directional amplification and find that the direction of amplification can be controlled by the phase differences between the effective optomechanical couplings. The effects of the gain rate of the active cavity and the effective coupling strengths on the maximum gain of the amplifier are discussed. We show that the noise added to this amplifier can be greatly suppressed in the large cooperativity limit.

  2. Maximizing Lumen Gain With Directional Atherectomy.

    Science.gov (United States)

    Stanley, Gregory A; Winscott, John G

    2016-08-01

    To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success. The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements. With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization. © The Author(s) 2016.

  3. Commutated automatic gain control system

    Science.gov (United States)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  4. Direct ink write fabrication of transparent ceramic gain media

    Science.gov (United States)

    Jones, Ivy Krystal; Seeley, Zachary M.; Cherepy, Nerine J.; Duoss, Eric B.; Payne, Stephen A.

    2018-01-01

    Solid-state laser gain media based on the garnet structure with two spatially distinct but optically contiguous regions have been fabricated. Transparent gain media comprised of a central core of Y2.97Nd0.03Al5.00O12.00 (Nd:YAG) and an undoped cladding region of Y3Al5O12 (YAG) were fabricated by direct ink write and transparent ceramic processing. Direct ink write (DIW) was employed to form the green body, offering a general route to preparing functionally structured solid-state laser gain media. Fully-dense transparent optical ceramics in a "top hat" geometry with YAG/Nd:YAG have been fabricated by DIW methods with optical scatter at 1064 nm of <3%/cm.

  5. Approach to interior design for passive direct gain solar homes

    Energy Technology Data Exchange (ETDEWEB)

    Kachadorian, C.C.

    1980-01-01

    In response to requests from buyers and builders of direct gain passive solar homes interior design criteria either specific to, or emphasized by, passive solar buildings are investigated. Problems of high sunlight penetration, secondary illumination, material selection, sound control and psychology are approached. Material deterioration, fading, glare, noise, and a sense of spacial confinement can be minimized, contributing to the appeal and saleability of passive solar homes.

  6. Beyond Multiplexing Gain in Large MIMO Systems

    DEFF Research Database (Denmark)

    Cakmak, Burak; Müller, Ralf R.; Fleury, Bernard Henri

    growth (multiplexing gain). Even when the channel entries are i.i.d. the deviation from the linear growth is significant. We also find an additive property of the deviation for a concatenated MIMO system. Finally, we quantify the deviation of the large SNR capacity from the exact capacity and find...

  7. High Gain and High Directive of Antenna Arrays Utilizing Dielectric Layer on Bismuth Titanate Ceramics

    Directory of Open Access Journals (Sweden)

    F. H. Wee

    2012-01-01

    Full Text Available A high gain and high directive microstrip patch array antenna formed from dielectric layer stacked on bismuth titanate (BiT ceramics have been investigated, fabricated, and measured. The antennas are designed and constructed with a combination of two-, four-, and six-BiT elements in an array form application on microwave substrate. For gain and directivity enhancement, a layer of dielectric was stacked on the BiT antenna array. We measured the gain and directivity of BiT array antennas with and without the dielectric layer and found that the gain of BiT array antenna with the dielectric layer was enhanced by about 1.4 dBi of directivity and 1.3 dB of gain over the one without the dielectric layer at 2.3 GHz. The impedance bandwidth of the BiT array antenna both with and without the dielectric layer is about 500 MHz and 350 MHz, respectively, which is suitable for the application of the WiMAX 2.3 GHz system. The utilization of BiT ceramics that covers about 90% of antenna led to high radiation efficiency, and small-size antennas were produced. In order to validate the proposed design, theoretical and measured results are provided and discussed.

  8. FAA Directives System

    Science.gov (United States)

    1992-08-26

    Consistent with the Federal Aviation Administration's mission to foster a safe, : secure, and efficient aviation system is the need for an effective and efficient : process for communitcating policy and procedures. The FAA Directives System : provide...

  9. Nuclear plants gain integrated information systems

    International Nuclear Information System (INIS)

    Villavicencio-Ramirez, A.; Rodriquez-Alvarez, J.M.

    1994-01-01

    With the objective of simplifying the complex mesh of computing devices employed within nuclear power plants, modern technology and integration techniques are being used to form centralized (but backed up) databases and distributed processing and display networks. Benefits are immediate as a result of the integration and the use of standards. The use of a unique data acquisition and database subsystem optimizes the high costs of engineering, as this task is done only once for the life span of the system. This also contributes towards a uniform user interface and allows for graceful expansion and maintenance. This article features an integrated information system, Sistema Integral de Informacion de Proceso (SIIP). The development of this system enabled the Laguna Verde Nuclear Power plant to fully use the already existing universe of signals and its related engineering during all plant conditions, namely, start up, normal operation, transient analysis, and emergency operation. Integrated systems offer many advantages over segregated systems, and this experience should benefit similar development efforts in other electric power utilities, not only for nuclear but also for other types of generating plants

  10. Gain Enhanced LTCC System-on-Package for UMRR Applications

    KAUST Repository

    Shamim, Atif

    2014-10-14

    An apparatus, system, and method for Gain Enhanced LTCC System-on-Package radar sensor. The sensor includes a substrate and an integrated circuit coupled to the substrate, where the integrated circuit is configured to transmit and receive radio frequency (RF) signals. An antenna may be coupled to the integrated circuit and a lens may be coupled to the antenna. The lens may be configured to enhance the gain of the sensor.

  11. Gain Enhanced LTCC System-on-Package for UMRR Applications

    KAUST Repository

    Shamim, Atif; Ghaffar, Farhan Abdul; Khalid, Muhammad Umair; Salama, Khaled N.

    2014-01-01

    An apparatus, system, and method for Gain Enhanced LTCC System-on-Package radar sensor. The sensor includes a substrate and an integrated circuit coupled to the substrate, where the integrated circuit is configured to transmit and receive radio frequency (RF) signals. An antenna may be coupled to the integrated circuit and a lens may be coupled to the antenna. The lens may be configured to enhance the gain of the sensor.

  12. Analysis and Evaluation of Performance Gains and Tradeoffs for Massive MIMO Systems

    Directory of Open Access Journals (Sweden)

    Saba Qasim Jabbar

    2016-09-01

    Full Text Available Massive MIMO technique offers significant performance gains for the future of wireless communications via improving the spectral efficiency, energy efficiency and the channel quality with simple linear processing such as maximum-ratio transmission (MRT or zero-forcing (ZF by providing each user a large degree of freedom. In this paper, the system performance gains are studied in a multi-cell downlink massive MIMO system under the main considerations such as perfect channel estimation, imperfect channel estimation and the effect of interference among cells due to pilot sequences contamination. Then, mathematical expressions are derived for these gains i.e., spatial multiplexing gain, array gain and spatial diversity gain. After that, essential tradeoffs among these gains are considered under the effect of non-orthogonal interference, these tradeoffs are: spatial diversity gain vs. spatial multiplexing gain and array gain vs. spatial multiplexing gain. Simulation results show that the unbounded number of base station antennas boosts the array gain through concentrating the energy to spatial directions where users are sited, hence diminishing loss in array gain due to pilot contamination. The simulation results reveal also that massive MIMO strengthens the spatial multiplexing gain through increasing the number of served users via the same system resources in spite the effect of inter-cell interference. Finally, the spatial diversity gain is measured in term of outage probability and the simulation results show that raising the number of antennas will improve the outage probability. Meanwhile increasing the number of served users will lead to degrade the outage probability per user due to non-orthogonal interference from other cells.

  13. SALICYLATE INCREASES THE GAIN OF THE CENTRAL AUDITORY SYSTEM

    Science.gov (United States)

    Sun, W.; Lu, J.; Stolzberg, D.; Gray, L.; Deng, A.; Lobarinas, E.; Salvi, R. J.

    2009-01-01

    High doses of salicylate, the anti-inflammatory component of aspirin, induce transient tinnitus and hearing loss. Systemic injection of 250 mg/kg of salicylate, a dose that reliably induces tinnitus in rats, significantly reduced the sound evoked output of the rat cochlea. Paradoxically, salicylate significantly increased the amplitude of the sound-evoked field potential from the auditory cortex (AC) of conscious rats, but not the inferior colliculus (IC). When rats were anesthetized with isoflurane, which increases GABA-mediated inhibition, the salicylate-induced AC amplitude enhancement was abolished, whereas ketamine, which blocks N-methyl-d-aspartate receptors, further increased the salicylate-induced AC amplitude enhancement. Direct application of salicylate to the cochlea, however, reduced the response amplitude of the cochlea, IC and AC, suggesting the AC amplitude enhancement induced by systemic injection of salicylate does not originate from the cochlea. To identify a behavioral correlate of the salicylate-induced AC enhancement, the acoustic startle response was measured before and after salicylate treatment. Salicylate significantly increased the amplitude of the startle response. Collectively, these results suggest that high doses of salicylate increase the gain of the central auditory system, presumably by down-regulating GABA-mediated inhibition, leading to an exaggerated acoustic startle response. The enhanced startle response may be the behavioral correlate of hyperacusis that often accompanies tinnitus and hearing loss. Published by Elsevier Ltd on behalf of IBRO. PMID:19154777

  14. EBO feed water distribution system, experience gained from operation

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O. [Energovyzkum, Brno (Switzerland); Schmidt, S.; Mihalik, M. [Atomove Elektrarne Bohunice, Jaslovske Bohunice (Switzerland)

    1997-12-31

    Advanced feed water distribution systems of the EBO design have been installed into steam generators at Units 3 and 4 of the NPP Jaslovske Bohunice (VVER 440). Experiences gained from the operation of steam generators with the advanced feed water distribution systems are discussed in the paper. (orig.). 4 refs.

  15. EBO feed water distribution system, experience gained from operation

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O [Energovyzkum, Brno (Switzerland); Schmidt, S; Mihalik, M [Atomove Elektrarne Bohunice, Jaslovske Bohunice (Switzerland)

    1998-12-31

    Advanced feed water distribution systems of the EBO design have been installed into steam generators at Units 3 and 4 of the NPP Jaslovske Bohunice (VVER 440). Experiences gained from the operation of steam generators with the advanced feed water distribution systems are discussed in the paper. (orig.). 4 refs.

  16. Optimum gain and phase for stochastic cooling systems

    International Nuclear Information System (INIS)

    Meer, S. van der.

    1984-01-01

    A detailed analysis of optimum gain and phase adjustment in stochastic cooling systems reveals that the result is strongly influenced by the beam feedback effect and that for optimum performance the system phase should change appreciably across each Schottky band. It is shown that the performance is not greatly diminished if a constant phase is adopted instead. On the other hand, the effect of mixing between pick-up and kicker (which produces a phase change similar to the optimum one) is shown to be less perturbing than is usually assumed, provided that the absolute value of the gain is not too far from the optimum value. (orig.)

  17. Prediction of direct and indirect genetic gains and genotypic correlations in rubber tree progenies

    Directory of Open Access Journals (Sweden)

    Cecília Khusala Verardi

    2011-09-01

    Full Text Available The objective of this work was to estimate the genetic parameters, genotypic and phenotypic correlations, and direct and indirect genetic gains among and within rubber tree (Hevea brasiliensis progenies. The experiment was set up at the Municipality of Jaú, SP, Brazil. A randomized complete block design was used, with 22 treatments (progenies, 6 replicates, and 10 plants per plot at a spacing of 3x3 m. Three‑year‑old progenies were assessed for girth, rubber yield, and bark thickness by direct and indirect gains and genotypic correlations. The number of latex vessel rings showed the best correlations, correlating positively and significantly with girth and bark thickness. Selection gains among progenies were greater than within progeny for all the variables analyzed. Total gains obtained were high, especially for girth increase and rubber yield, which were 93.38 and 105.95%, respectively. Young progeny selection can maximize the expected genetic gains, reducing the rubber tree selection cycle.

  18. Liquid scintillation counting system with automatic gain correction

    International Nuclear Information System (INIS)

    Frank, R.B.

    1976-01-01

    An automatic liquid scintillation counting apparatus is described including a scintillating medium in the elevator ram of the sample changing apparatus. An appropriate source of radiation, which may be the external source for standardizing samples, produces reference scintillations in the scintillating medium which may be used for correction of the gain of the counting system

  19. Gain Scheduling Control based on Closed-Loop System Identification

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    the first and a second operating point is identified in closed-loop using system identification methods with open-loop properties. Next, a linear controller is designed for this linearised model, and gain scheduling control can subsequently be achieved by interpolating between each controller...

  20. Rate adaptive multilevel coded modulation with high coding gain in intensity modulation direct detection optical communication

    Science.gov (United States)

    Xiao, Fei; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Qi; Tian, Qinghua; Tian, Feng; Wang, Yongjun; Rao, Lan; Ullah, Rahat; Zhao, Feng; Li, Deng'ao

    2018-02-01

    A rate-adaptive multilevel coded modulation (RA-MLC) scheme based on fixed code length and a corresponding decoding scheme is proposed. RA-MLC scheme combines the multilevel coded and modulation technology with the binary linear block code at the transmitter. Bits division, coding, optional interleaving, and modulation are carried out by the preset rule, then transmitted through standard single mode fiber span equal to 100 km. The receiver improves the accuracy of decoding by means of soft information passing through different layers, which enhances the performance. Simulations are carried out in an intensity modulation-direct detection optical communication system using MATLAB®. Results show that the RA-MLC scheme can achieve bit error rate of 1E-5 when optical signal-to-noise ratio is 20.7 dB. It also reduced the number of decoders by 72% and realized 22 rate adaptation without significantly increasing the computing time. The coding gain is increased by 7.3 dB at BER=1E-3.

  1. Gain Scheduling of PID Controller Based on Fuzzy Systems

    Directory of Open Access Journals (Sweden)

    Singh Sandeep

    2016-01-01

    Full Text Available This paper aims to utilize fuzzy rules and reasoning to determine the controller parameters and the PID controller generates the control signal. The objective of this study is to simulate the proposed scheme on various processes and arrive at results providing better response of the system when compared with best industrial auto-tuning technique: Ziegler-Nichols. The proposed scheme is based upon the Ultimate Gain (Ku and the Period (Tu of the system. The error and rate of change in error gains are tuned manually to get the desired response using LabVIEW. This can also be done with various optimization techniques. A thumb rule for choosing the ranges for Kc, Kd and Ki has been obtained experimentally.

  2. Method and system for edge cladding of laser gain media

    Science.gov (United States)

    Bayramian, Andrew James; Caird, John Allyn; Schaffers, Kathleen Irene

    2014-03-25

    A gain medium operable to amplify light at a gain wavelength and having reduced transverse ASE includes an input surface and an output surface opposing the input surface. The gain medium also includes a central region including gain material and extending between the input surface and the output surface along a longitudinal optical axis of the gain medium. The gain medium further includes an edge cladding region surrounding the central region and extending between the input surface and the output surface along the longitudinal optical axis of the gain medium. The edge cladding region includes the gain material and a dopant operable to absorb light at the gain wavelength.

  3. Gain scheduling controller for pitch control of a TRMS system

    Science.gov (United States)

    Bhagyalakshmi, R.; Rashmi, GP; Jaganatha Pandian, B.

    2017-11-01

    Gain scheduling is a control technique which is applied for the control of non-linear systems by using a family of linear controllers at different operating points so as to increase the range of operation of the process. The dynamics of any nonlinear system changes with respect to operating points. These operating points are characterized by one or more variables known as scheduling variables. In such cases, we linearize the system at different equilibrium points. Due to the high amount of non-linearities and complexity in the aerodynamic design, modelling of other unmanned aerial vehicles have been replaced here with twin rotor system. The linearized system is then controlled by using PID controllers which are designed with respect to the obtained operating points. Linearizing of the non-linear system, designing and tuning of PID are being implemented using different MATLAB functions.

  4. Direct Communication Systems

    OpenAIRE

    Krajačić, Ivan

    2016-01-01

    Today we use numerous methods of direct communications, for which we use a technical term Unified Communications. It is almost impossible to imagine the business world today without Unified Communications, which are improving productivity and reducing costs. The goal of using Unified Communications is to ensure a consistent user experience at any location and any device. Skype for Business, a Microsoft product, is one of the solutions for Unified Communications and is described in this thesis...

  5. Optical gain in colloidal quantum dots achieved with direct-current electrical pumping

    Science.gov (United States)

    Lim, Jaehoon; Park, Young-Shin; Klimov, Victor I.

    2018-01-01

    Chemically synthesized semiconductor quantum dots (QDs) can potentially enable solution-processable laser diodes with a wide range of operational wavelengths, yet demonstrations of lasing from the QDs are still at the laboratory stage. An important challenge--realization of lasing with electrical injection--remains unresolved, largely due to fast nonradiative Auger recombination of multicarrier states that represent gain-active species in the QDs. Here we present population inversion and optical gain in colloidal nanocrystals realized with direct-current electrical pumping. Using continuously graded QDs, we achieve a considerable suppression of Auger decay such that it can be outpaced by electrical injection. Further, we apply a special current-focusing device architecture, which allows us to produce high current densities (j) up to ~18 A cm-2 without damaging either the QDs or the injection layers. The quantitative analysis of electroluminescence and current-modulated transmission spectra indicates that with j = 3-4 A cm-2 we achieve the population inversion of the band-edge states.

  6. Recruitment of young adults for weight gain prevention: randomized comparison of direct mail strategies.

    Science.gov (United States)

    Crane, Melissa M; LaRose, Jessica Gokee; Espeland, Mark A; Wing, Rena R; Tate, Deborah F

    2016-06-08

    Recruiting young adults (ages 18-35 years) into weight gain prevention intervention studies is challenging and men are particularly difficult to reach. This paper describes two studies designed to improve recruitment for a randomized trial of weight gain prevention interventions. Study 1 used a quasi-experimental design to test the effect of two types of direct mailings on their overall reach. Study 2 used a randomized design to test the effect of using targeted messages to increase recruitment of men into the trial. For Study 1, 60,000 male and female young-adult households were randomly assigned to receive either a recruitment brochure or postcard. Visits to recruitment websites during each mailing period were used to assess response to each mailing. Study 2 focused on postcard recruitment only. These households received either a targeted or generic recruitment postcard, where targeted postcards included the word "Men" in the headline text. Response rates to each type of card were categorized based on participant report of mailing received. The reach of the postcards and brochures were similar (421 and 386 website visits, respectively; P = 0.22). Individuals who received the brochure were more likely to initiate the online screener than those who received a postcard (P = 0.01). In Study 2, of those who completed the telephone screening, 60.9 % of men (n = 23) had received the targeted postcard as compared to the generic postcard (39.1 %, P = 0.30). The reverse was true for women (n = 62, 38.7 vs. 61.3 %, P = 0.08). These studies suggest there was little difference in the reach of postcards versus brochures. However, recipients of brochures were more likely to continue to the next stage of study participation. As expected, men's response to the weight gain prevention messages was lower than women's response; but using targeted messages appears to have modestly increased the proportion of male respondents. These studies add to the limited

  7. Experience gained with Euratom's nuclear materials accounting and reporting system

    International Nuclear Information System (INIS)

    Schmitt, M.; Kschwendt, H.; Maxwell, A.G.; Littlejohn, M.

    1979-01-01

    The entry into force of the Verification Agreement in early 1977, linked to the wish to update the old Euratom System created in 1959, required that a new Euratom system (Community Regulation) be established. The main aspects of this new system, together with the practical experience gained in one and a half years operation, are presented. Certain basic accounting principles incorporated in the Euratom system, which are somewhat different from IAEA principles, are discussed in detail. This includes the notion of accounting date, some correction procedure aspects as well as the continuous updating of the book inventory to the physical reality in form of inventory changes. The effect of these differences when comparing IAEA and Euratom data is also mentioned. Furthermore, certain of the verifications carried out routinely on the operator's reports as well as on the reports submitted by Euratom to IAEA, are described and quantifications are given. Some mention is also made of areas where Euratom's role goes beyond that of the IAEA, i.e. the reporting implications of accounting for material by origin and control of particular use of the materials as well as verification of ore production and processing activities. Finally, improvements and simplifications concerning reports to the IAEA are proposed. (author)

  8. LPV gain-scheduled control of SCR aftertreatment systems

    Science.gov (United States)

    Meisami-Azad, Mona; Mohammadpour, Javad; Grigoriadis, Karolos M.; Harold, Michael P.; Franchek, Matthew A.

    2012-01-01

    Hydrocarbons, carbon monoxide and some of other polluting emissions produced by diesel engines are usually lower than those produced by gasoline engines. While great strides have been made in the exhaust aftertreatment of vehicular pollutants, the elimination of nitrogen oxide (NO x ) from diesel vehicles is still a challenge. The primary reason is that diesel combustion is a fuel-lean process, and hence there is significant unreacted oxygen in the exhaust. Selective catalytic reduction (SCR) is a well-developed technology for power plants and has been recently employed for reducing NO x emissions from automotive sources and in particular, heavy-duty diesel engines. In this article, we develop a linear parameter-varying (LPV) feedforward/feedback control design method for the SCR aftertreatment system to decrease NO x emissions while keeping ammonia slippage to a desired low level downstream the catalyst. The performance of the closed-loop system obtained from the interconnection of the SCR system and the output feedback LPV control strategy is then compared with other control design methods including sliding mode, and observer-based static state-feedback parameter-varying control. To reduce the computational complexity involved in the control design process, the number of LPV parameters in the developed quasi-LPV (qLPV) model is reduced by applying the principal component analysis technique. An LPV feedback/feedforward controller is then designed for the qLPV model with reduced number of scheduling parameters. The designed full-order controller is further simplified to a first-order transfer function with a parameter-varying gain and pole. Finally, simulation results using both a low-order model and a high-fidelity and high-order model of SCR reactions in GT-POWER interfaced with MATLAB/SIMULINK illustrate the high NO x conversion efficiency of the closed-loop SCR system using the proposed parameter-varying control law.

  9. Postcessation weight gain concern as a barrier to smoking cessation: Assessment considerations and future directions.

    Science.gov (United States)

    Germeroth, Lisa J; Levine, Michele D

    2018-01-01

    Concern about postcessation weight gain may be one potential barrier to quitting smoking. In this 'mini-review' of recent literature, we summarize findings on the relationship between postcessation weight gain concern and smoking cessation, and evaluate varied use of postcessation weight gain concern assessments and potential moderators of the postcessation weight gain concern-cessation association. We conducted a search using the terms "smoking" OR "smoking cessation" AND "weight concern" for articles published between January 1, 2011 and December 31, 2016. We identified 17 studies assessing postcessation weight gain concern, seven of which evaluated the postcessation weight gain concern-cessation association. The relationship between postcessation weight gain concern and smoking cessation was mixed. Recent studies varied in their assessments of postcessation weight gain concern, many of which were not validated and assessed correlates of this construct. Studies varied in their adjustment of demographic (e.g., sex), smoking-specific (e.g., smoking level), and weight-specific (e.g., body mass index) variables. The use of non-validated assessments and variability in testing covariates/moderators may contribute to conflicting results regarding the postcessation weight gain concern-cessation relationship. We recommend validating an assessment of postcessation weight gain concern, maintaining vigilance in testing and reporting covariates/moderators, and investigating trajectories of this construct over time and by smoking status to inform future assessment and intervention efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. On the Performance Analysis of Dual-Hop FSO Fixed Gain Transmission Systems

    KAUST Repository

    Zedini, Emna

    2015-12-12

    Novel exact closed-form results for the end-to-end performance analysis of dual-hop free-space optical (FSO) fixed-gain relaying systems under heterodyne detection as well as intensity modulation with direct detection techniques in the presence of atmospheric turbulence as well as pointing errors are presented. By using dual-hop FSO relaying, we demonstrate a better system performance relative to the single FSO link. Numerical and Monte-Carlo simulation results are provided to verify the accuracy of the newly proposed results, and a perfect agreement is observed.

  11. An offset tone based gain stabilization technique for mixed-signal RF measurement systems

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Gopal, E-mail: gjos@barc.gov.in [BARC, Mumbai 400085 (India); Motiwala, Paresh D.; Randale, G.D.; Singh, Pitamber [BARC, Mumbai 400085 (India); Agarwal, Vivek; Kumar, Girish [IIT Bombay, Powai, Mumbai 400076 (India)

    2015-09-21

    This paper describes a gain stabilization technique for a RF signal measurement system. A sinusoidal signal of known amplitude, phase and close enough in frequency is added to the main, to be measured RF signal at the input of the analog section. The system stabilizes this offset tone in the digital domain, as it is sampled at the output of the analog section. This process generates a correction factor needed to stabilize the magnitude of the gain of the analog section for the main RF signal. With the help of a simple calibration procedure, the absolute amplitude of the main RF signal can be measured. The technique is especially suited for a system that processes signals around a single frequency, employs direct signal conversion into the digital domain, and processes subsequent steps in an FPGA. The inherent parallel signal processing in an FPGA-based implementation allows a real time stabilization of the gain. The effectiveness of the technique is derived from the fact, that the gain stabilization stamped to the main RF signal measurement branch requires only a few components in the system to be inherently stable. A test setup, along with experimental results is presented from the field of RF instrumentation for particle accelerators. Due to the availability of a phase synchronized RF reference signal in these systems, the measured phase difference between the main RF and the RF reference is also stabilized using this technique. A scheme of the signal processing is presented, where a moving average filter has been used to filter out not only the unwanted frequencies, but also to separate the main RF signal from the offset tone signal. This is achieved by a suitable choice of sampling and offset tone frequencies. The presented signal processing scheme is suitable to a variety of RF measurement applications.

  12. Frequency domain indirect identification of AMB rotor systems based on fictitious proportional feedback gain

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hyeong Joon [Dept. of Mechanical Engineering, Soongsil University, Seoul (Korea, Republic of); Kim, Chan Jung [Dept. of Mechanical Design Engineering, Pukyong National University, Busan(Korea, Republic of)

    2016-12-15

    It is very difficult to directly identify an unstable system with uncertain dynamics from frequency domain input-output data. Hence, in these cases, closed-loop frequency responses calculated using a fictitious feedback could be more identifiable than open-loop data. This paper presents a frequency domain indirect identification of AMB rotor systems based on a Fictitious proportional feedback gain (FPFG). The closed-loop effect due to the FPFG can enhance the detectability of the system by moving the system poles, and significantly weigh the target mode in the frequency domain. The effectiveness of the proposed identification method was verified through the frequency domain identification of active magnetic bearing rotor systems.

  13. An Improved Adaptive-Torque-Gain MPPT Control for Direct-Driven PMSG Wind Turbines Considering Wind Farm Turbulences

    Directory of Open Access Journals (Sweden)

    Xiaolian Zhang

    2016-11-01

    Full Text Available Maximum power point tracking (MPPT plays an important role in increasing the efficiency of a wind energy conversion system (WECS. In this paper, three conventional MPPT methods are reviewed: power signal feedback (PSF control, decreased torque gain (DTG control, and adaptive torque gain (ATG control, and their potential challenges are investigated. It is found out that the conventional MPPT method ignores the effect of wind turbine inertia and wind speed fluctuations, which lowers WECS efficiency. Accordingly, an improved adaptive torque gain (IATG method is proposed, which customizes adaptive torque gains and enhances MPPT performances. Specifically, the IATG control considers wind farm turbulences and works out the relationship between the optimal torque gains and the wind speed characteristics, which has not been reported in the literature. The IATG control is promising, especially under the ongoing trend of building wind farms with large-scale wind turbines and at low and medium wind speed sites.

  14. High gain direct drive target designs and supporting experiments with KrF

    International Nuclear Information System (INIS)

    Karasik, Max; Bates, Jason W.; Aglitskiy, Yefim

    2013-01-01

    Krypton-fluoride laser is an attractive inertial fusion energy driver from the standpoint of target physics. Target designs taking advantage of zooming, shock ignition, and favorable physics with KrF reach energy gains of 200 with sub-MJ laser energy. The designs are robust under 2D simulations. Experiments on the Nike KrF laser support the physics basis. (author)

  15. How does a specific learning and memory system in the mammalian brain gain control of behavior?

    Science.gov (United States)

    McDonald, Robert J; Hong, Nancy S

    2013-11-01

    This review addresses a fundamental, yet poorly understood set of issues in systems neuroscience. The issues revolve around conceptualizations of the organization of learning and memory in the mammalian brain. One intriguing, and somewhat popular, conceptualization is the idea that there are multiple learning and memory systems in the mammalian brain and they interact in different ways to influence and/or control behavior. This approach has generated interesting empirical and theoretical work supporting this view. One issue that needs to be addressed is how these systems influence or gain control of voluntary behavior. To address this issue, we clearly specify what we mean by a learning and memory system. We then review two types of processes that might influence which memory system gains control of behavior. One set of processes are external factors that can affect which system controls behavior in a given situation including task parameters like the kind of information available to the subject, types of training experience, and amount of training. The second set of processes are brain mechanisms that might influence what memory system controls behavior in a given situation including executive functions mediated by the prefrontal cortex; switching mechanisms mediated by ascending neurotransmitter systems, the unique role of the hippocampus during learning. The issue of trait differences in control of different learning and memory systems will also be considered in which trait differences in learning and memory function are thought to potentially emerge from differences in level of prefrontal influence, differences in plasticity processes, differences in ascending neurotransmitter control, differential access to effector systems like motivational and motor systems. Finally, we present scenarios in which different mechanisms might interact. This review was conceived to become a jumping off point for new work directed at understanding these issues. The outcome of

  16. Outage probability of dual-hop FSO fixed gain relay transmission systems

    KAUST Repository

    Zedini, Emna

    2016-12-24

    In this paper, we analyze the end-to-end performance of dual-hop free-space optical (FSO) fixed gain relaying systems in the presence of atmospheric turbulence as well as pointing errors. More specifically, an exact closed-form expression for the outage probability is presented in terms of the bivariate Fox\\'s H function that accounts for both heterodyne detection as well as intensity modulation with direct detection. At high signal-to-noise ratio (SNR) regime, we provide very tight asymptotic result for this performance metric in terms of simple elementary functions. By using dual-hop FSO relaying, we demonstrate a better system performance as compared to the single FSO link. Numerical and Monte-Carlo simulation results are provided to verify the accuracy of the newly proposed results, and a perfect agreement is observed.

  17. Omega experiments and preparation for moderate-gain direct-drive experiments on Nif

    International Nuclear Information System (INIS)

    Mr Crory, R.L.; Bahr, R.E.; Boehly, T.R.

    2000-01-01

    Direct-drive laser-fusion ignition experiments rely on detailed understanding and control of irradiation uniformity, Rayleigh-Taylor instability, and target fabrication. LLE is investigating various theoretical aspects of a direct-drive NIF ignition target based on an 'all-DT' design: a spherical target of ∼ 3.5 mm diameter, 1 to 2 μm if CH wall thickness, and a ∼ 350 μm DT-ice layer near the triple point of DT (μ19K). OMEGA experiments are designed to address the critical issues related to direct-drive laser fusion and to provide the necessary data to validate the predictive capability of LLE computer codes. The future cryogenic targets used on OMEGA are hydrodynamically equivalent to those planned for the NIF. The current experimental studies on OMEGA address all of the essential components of direct-drive laser fusion: irradiation uniformity and laser imprinting, Rayleigh-Taylor growth and saturation, compressed core performance and shell-fuel mixing, laser-plasma interactions and their effect on target performance, and cryogenic target fabrication and handling. (authors)

  18. Internal heat gain from different light sources in the building lighting systems

    Directory of Open Access Journals (Sweden)

    Suszanowicz Dariusz

    2017-01-01

    Full Text Available EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  19. Internal heat gain from different light sources in the building lighting systems

    Science.gov (United States)

    Suszanowicz, Dariusz

    2017-10-01

    EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output) were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  20. Performance Analysis of Spectral Amplitude Coding Based OCDMA System with Gain and Splitter Mismatch

    Science.gov (United States)

    Umrani, Fahim A.; Umrani, A. Waheed; Umrani, Naveed A.; Memon, Kehkashan A.; Kalwar, Imtiaz Hussain

    2013-09-01

    This paper presents the practical analysis of the optical code-division multiple-access (O-CDMA) systems based on perfect difference codes. The work carried out use SNR criterion to select the optimal value of avalanche photodiodes (APD) gain and shows how the mismatch in the splitters and gains of the APD used in the transmitters and receivers of network can degrade the BER performance of the system. The investigations also reveal that higher APD gains are not suitable for such systems even at higher powers. The system performance, with consideration of shot noise, thermal noise, bulk and surface leakage currents is also investigated.

  1. Optical gain in an optically driven three-level ? system in atomic Rb vapor

    Science.gov (United States)

    Ballmann, C. W.; Yakovlev, V. V.

    2018-06-01

    In this work, we report experimentally achieved optical gain of a weak probe beam in a three-level ? system in a low density Rubidium vapor cell driven by a single pump beam. The maximum measured gain of the probe beam was about 0.12%. This work could lead to new approaches for enhancing molecular spectroscopy applications.

  2. Factorization and the synthesis of optimal feedback gains for distributed parameter systems

    Science.gov (United States)

    Milman, Mark H.; Scheid, Robert E.

    1990-01-01

    An approach based on Volterra factorization leads to a new methodology for the analysis and synthesis of the optimal feedback gain in the finite-time linear quadratic control problem for distributed parameter systems. The approach circumvents the need for solving and analyzing Riccati equations and provides a more transparent connection between the system dynamics and the optimal gain. The general results are further extended and specialized for the case where the underlying state is characterized by autonomous differential-delay dynamics. Numerical examples are given to illustrate the second-order convergence rate that is derived for an approximation scheme for the optimal feedback gain in the differential-delay problem.

  3. Gain measurements of the Ca-Xe charge exchange system. [for UV lasers

    Science.gov (United States)

    Michels, C. J.; Chubb, D. L.

    1978-01-01

    Charge-exchange-pumped Ca(+) was studied for possible positive laser gain at 370.6 and 315.9 nm using an Xe MPD arc as the Xe(+) source. The present paper describes the MPD arc, the calcium injection system, the diagnostics for gain, and spontaneous emission measurements and results. No positive gain measurements were observed. A small Xe-Ca charge exchange cross section compared to He-metal laser systems charge exchange cross sections is the most probable reason why the result was negative.

  4. Asynchronous L1-gain control of uncertain switched positive linear systems with dwell time.

    Science.gov (United States)

    Li, Yang; Zhang, Hongbin

    2018-04-01

    In this paper, dwell time (DT) stability, L 1 -gain performance analysis and asynchronous L 1 -gain controller design problems of uncertain switched positive linear systems (SPLSs) are investigated. Via a time-scheduled multiple linear co-positive Lyapunov function (TSMLCLF) approach, convex sufficient conditions of DT stability and L 1 -gain performance of SPLSs with interval and polytopic uncertainties are presented. Furthermore, by utilizing the feature that the TSMLCLF keeps decreasing even if the controller is running asynchronously with the system, the asynchronous L 1 -gain controller design problem of SPLSs with interval and polytopic uncertainties is investigated. Convex sufficient conditions of the existence of time-varying asynchronous state-feedback controller which can ensure the closed-loop system's positivity, stability and L 1 -gain performance are established, and the controller gain matrices can be calculated instantaneously online. The obtained L 1 -gain in the paper is standard. All the results are presented in terms of linear programming. A practical example is provided to show the effectiveness of the results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Beam energy gain fluctuation in a linac caused by RF system noise

    International Nuclear Information System (INIS)

    Sakaki, H.; Yoshikawa, H.; Hori, T.; Yokomizo, H.

    2002-01-01

    In this paper, energy gain fluctuation caused by white noise in a linear accelerator is calculated. First, we formulate a computational procedure to determine the energy gain in the acceleration structure. Then, using this computational procedure, the size of the white noise of the gain is calculated. These noise sources are caused by various RF components, especially the thyratron. The calculated gain fluctuation per one RF system is ±0.054%∼±0.134%(±3σ). In general, it is difficult to control white noise. This gain fluctuation is composed only of the white noise. Therefore, this value has the same meaning as a 'Control threshold'. Thus, the control method can be evaluated based on this value

  6. Comparison of gradient methods for gain tuning of a PD controller applied on a quadrotor system

    Science.gov (United States)

    Kim, Jinho; Wilkerson, Stephen A.; Gadsden, S. Andrew

    2016-05-01

    Many mechanical and electrical systems have utilized the proportional-integral-derivative (PID) control strategy. The concept of PID control is a classical approach but it is easy to implement and yields a very good tracking performance. Unmanned aerial vehicles (UAVs) are currently experiencing a significant growth in popularity. Due to the advantages of PID controllers, UAVs are implementing PID controllers for improved stability and performance. An important consideration for the system is the selection of PID gain values in order to achieve a safe flight and successful mission. There are a number of different algorithms that can be used for real-time tuning of gains. This paper presents two algorithms for gain tuning, and are based on the method of steepest descent and Newton's minimization of an objective function. This paper compares the results of applying these two gain tuning algorithms in conjunction with a PD controller on a quadrotor system.

  7. Pulsed neutron logging system for inelastic scattering gamma rays with gain compensation

    International Nuclear Information System (INIS)

    Schultz, W.E.; Smith, H.D. Jr.

    1976-01-01

    An illustrative embodiment of the invention includes methods for linearizing the gain of borehole gamma ray energy measurement apparatus. A known energy peak (or peaks) which is prominent in the gamma ray energy spectra of borehole measurements is monitored and any drift in its apparent location in the energy spectrum is used to generate an error voltage. The error voltage is applied in an inverse feedback manner to control the gain of system amplifiers to cancel the drift

  8. OFDM AF Variable Gain Relay System for the Next Generation Mobile Cellular

    Directory of Open Access Journals (Sweden)

    E. Kocan

    2012-06-01

    Full Text Available In this paper we present analytical performance evaluation of a dual-hop OFDM amplify-andforward (AF variable gain (VG relay system implementing ordered subcarrier mapping (SCM at the relay station (R, considered to be a very interesting solution for the next generation mobile cellular networks. A scenario with no direct communication between the source of information (S and destination terminal (D, with the Rayleigh fading statistics on both hops is assumed. A closed form analytical expression for the bit error rate (BER performance of the considered system with DPSK modulation is derived, while for its ergodic capacity performance, a tight upper bound expression is obtained. The accuracy of the undertaken analytical approach is confirmed through comparison with simulation results. It is shown that significant capacity enhancement can be achieved through SCM implementation at R, for all the signal-to-noise ratio (SNR values on both hops, but especially in the region of small SNRs on hops. BER analysis reveals that in the region of small and medium average SNRs on both hops BER performance may also be improved with SCM at R station.

  9. Analyzing the effect of gain time on soft task scheduling policies in real-time systems

    OpenAIRE

    Búrdalo Rapa, Luis Antonio; Terrasa Barrena, Andrés Martín; Espinosa Minguet, Agustín Rafael; García Fornes, Ana María

    2012-01-01

    In hard real-time systems, gain time is defined as the difference between the Worst Case Execution Time (WCET) of a hard task and its actual processor consumption at runtime. This paper presents the results of an empirical study about how the presence of a significant amount of gain time in a hard real-time system questions the advantages of using the most representative scheduling algorithms or policies for aperiodic or soft tasks in fixed-priority preemptive systems. The work presented here...

  10. ℋ∞ constant gain state feedback stabilization of stochastic hybrid systems with Wiener process

    Directory of Open Access Journals (Sweden)

    E. K. Boukas

    2004-01-01

    Full Text Available This paper considers the stabilization problem of the class of continuous-time linear stochastic hybrid systems with Wiener process. The ℋ∞ state feedback stabilization problem is treated. A state feedback controller with constant gain that does not require access to the system mode is designed. LMI-based conditions are developed to design the state feedback controller with constant gain that stochastically stabilizes the studied class of systems and, at the same time, achieve the disturbance rejection of a desired level. The minimum disturbance rejection is also determined. Numerical examples are given to show the usefulness of the proposed results.

  11. Study on automatic tuning of ship`s PID regulators; Hakuyo seigyo system no gain jido chosei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Nakatani, T. [Toyama Mercantile Marine College, Toyama (Japan); Otsu, K.; Moriyoshi, N. [Tokyo Univ. of Mercantile Marine, Tokyo (Japan); Okazaki, T. [Nagoya Institute of Technology, Nagoya (Japan)

    1996-12-31

    Proportional, integral and derivative (PID) controls are used for a steering system and a main engine control unit installed in a vessel. Among them, this paper describes effectiveness of a PID gain tuning method using a limit cycle by means of relay control which is safer and simpler than conventional limit sensitivity methods. The present method was applied to an actual marine control system to conduct an actual vessel experiment. As a result of applying the method to a bow azimuth control system using a rudder, a new azimuth setting was set with an overshoot of 1.6 degrees in a ten-degree azimuth changing experiment. With respect to direction maintaining steering performance, the present method was capable of controlling the direction at a speed loss to about 80% of the ship`s autopilot. As a result of applying the method to a bow azimuth control system using a bow thruster, direction maintaining and changing control was realized in a low speed range in which rudder effect is lost. As a result of applying it to a main engine governor system and performing control of main engine rotation speed, it was found possible to derive control gains in a safe state without applying an excessive load to the main engine both under load and no load conditions. 14 refs., 8 figs., 11 tabs.

  12. Study on automatic tuning of ship`s PID regulators; Hakuyo seigyo system no gain jido chosei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Nakatani, T [Toyama Mercantile Marine College, Toyama (Japan); Otsu, K; Moriyoshi, N [Tokyo Univ. of Mercantile Marine, Tokyo (Japan); Okazaki, T [Nagoya Institute of Technology, Nagoya (Japan)

    1997-12-31

    Proportional, integral and derivative (PID) controls are used for a steering system and a main engine control unit installed in a vessel. Among them, this paper describes effectiveness of a PID gain tuning method using a limit cycle by means of relay control which is safer and simpler than conventional limit sensitivity methods. The present method was applied to an actual marine control system to conduct an actual vessel experiment. As a result of applying the method to a bow azimuth control system using a rudder, a new azimuth setting was set with an overshoot of 1.6 degrees in a ten-degree azimuth changing experiment. With respect to direction maintaining steering performance, the present method was capable of controlling the direction at a speed loss to about 80% of the ship`s autopilot. As a result of applying the method to a bow azimuth control system using a bow thruster, direction maintaining and changing control was realized in a low speed range in which rudder effect is lost. As a result of applying it to a main engine governor system and performing control of main engine rotation speed, it was found possible to derive control gains in a safe state without applying an excessive load to the main engine both under load and no load conditions. 14 refs., 8 figs., 11 tabs.

  13. Method and circuit for stabilizing conversion gain of radiation detectors of a radiation detection system

    International Nuclear Information System (INIS)

    Stoub, E.W.

    1986-01-01

    A method is described for calibrating the gain of an array of radiation detectors of a radiation detection system comprising the steps of: (a) measuring in parallel for each radiation detector using a predetermined calibration point the energy map status, thereby obtaining an energy response vector whose elements correspond to the individual output of each radiation detector, each predetermined calibration point being a prescribed location corresponding to one of the radiation detectors; (b) multiplying that energy response vector with a predetermined deconvolution matrix, the deconvolution matrix being the inversion of a contribution matrix containing matrix elements C/sub IJ/, each such matrix element C/sub IJ/ of the contribution matrix representing the relative contribution level of a radiation detector j of the detection system for a point radiation source placed at a location i, thereby obtaining a gain vector product for the radiation detectors; (c) adjusting the gains of the radiation detectors with respect to the gain vector product such that a unity gain vector is essentially obtained; (d) measuring again the energy map status according to step (a); and (e) if the energy map status fails to essentially produce a unity gain vector repeat steps (a) to (d) until the energy map status substantially corresponds to unity

  14. Analysis of nonlinear systems with time varying inputs and its application to gain scheduling

    Directory of Open Access Journals (Sweden)

    J.-T. Lim

    1996-01-01

    Full Text Available An analytical framework for analysis of a class of nonlinear systems with time varying inputs is presented. It is shown that the trajectories of the transformed nonlinear systems are uniformly bounded with an ultimate bound under certain conditions shown in this paper. The result obtained is useful for applications, in particular, analysis and design of gain scheduling.

  15. Sensitivity and environmental response of the CMS RPC gas gain monitoring system

    CERN Document Server

    Benussi, L.; Colafranceschi, S.; Fabbri, F.L.; Giardoni, M.; Ortenzi, B.; Paolozzi, A.; Passamonti, L.; Pierluigi, D.; Ponzio, B.; Russo, A.; Colaleo, A.; Loddo, F.; Maggi, M.; Ranieri, A.; Abbrescia, M.; Iaselli, G.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Romano, F.; Roselli, G.; Trentadue, R.; Tupputi, S.; Guida, R.; Polese, G.; Sharma, A.; Cimmino, A.; Lomidze, D.; Paolucci, D.; Piccolo, P.; Baesso, P.; Necchi, M.; Pagano, D.; Ratti, S.P.; Vitulo, P.; Viviani, C.

    Results from the gas gain monitoring (GGM) system for the muon detector using RPC in the CMS experiment at the LHC is presented. The system is designed to provide fast and accurate determination of any shift in the working point of the chambers due to gas mixture changes.

  16. Direct output feedback control of discrete-time systems

    International Nuclear Information System (INIS)

    Lin, C.C.; Chung, L.L.; Lu, K.H.

    1993-01-01

    An optimal direct output feedback control algorithm is developed for discrete-time systems with the consideration of time delay in control force action. Optimal constant output feedback gains are obtained through variational process such that certain prescribed quadratic performance index is minimized. Discrete-time control forces are then calculated from the multiplication of output measurements by these pre-calculated feedback gains. According to the proposed algorithm, structural system is assured to remain stable even in the presence of time delay. The number of sensors and controllers may be very small as compared with the dimension of states. Numerical results show that direct velocity feedback control is more sensitive to time delay than state feedback but, is still quite effective in reducing the dynamic responses under earthquake excitation. (author)

  17. Reliable gain-scheduled control of discrete-time systems and its application to CSTR model

    Science.gov (United States)

    Sakthivel, R.; Selvi, S.; Mathiyalagan, K.; Shi, Y.

    2016-10-01

    This paper is focused on reliable gain-scheduled controller design for a class of discrete-time systems with randomly occurring nonlinearities and actuator fault. Further, the nonlinearity in the system model is assumed to occur randomly according to a Bernoulli distribution with measurable time-varying probability in real time. The main purpose of this paper is to design a gain-scheduled controller by implementing a probability-dependent Lyapunov function and linear matrix inequality (LMI) approach such that the closed-loop discrete-time system is stochastically stable for all admissible randomly occurring nonlinearities. The existence conditions for the reliable controller is formulated in terms of LMI constraints. Finally, the proposed reliable gain-scheduled control scheme is applied on continuously stirred tank reactor model to demonstrate the effectiveness and applicability of the proposed design technique.

  18. Hamiltonian formulation of systems with balanced loss-gain and exactly solvable models

    Science.gov (United States)

    Ghosh, Pijush K.; Sinha, Debdeep

    2018-01-01

    A Hamiltonian formulation of generic many-body systems with balanced loss and gain is presented. It is shown that a Hamiltonian formulation is possible only if the balancing of loss and gain terms occurs in a pairwise fashion. It is also shown that with the choice of a suitable co-ordinate, the Hamiltonian can always be reformulated in the background of a pseudo-Euclidean metric. If the equations of motion of some of the well-known many-body systems like Calogero models are generalized to include balanced loss and gain, it appears that the same may not be amenable to a Hamiltonian formulation. A few exactly solvable systems with balanced loss and gain, along with a set of integrals of motion are constructed. The examples include a coupled chain of nonlinear oscillators and a many-particle Calogero-type model with four-body inverse square plus two-body pair-wise harmonic interactions. For the case of nonlinear oscillators, stable solution exists even if the loss and gain parameter has unbounded upper range. Further, the range of the parameter for which the stable solutions are obtained is independent of the total number of the oscillators. The set of coupled nonlinear equations are solved exactly for the case when the values of all the constants of motions except the Hamiltonian are equal to zero. Exact, analytical classical solutions are presented for all the examples considered.

  19. Resolved discrepancies between visible spontaneous Raman cross-section and direct near-infrared Raman gain measurements in TeO2-based glasses.

    Science.gov (United States)

    Rivero, Clara; Stegeman, Robert; Couzi, Michel; Talaga, David; Cardinal, Thierry; Richardson, Kathleen; Stegeman, George

    2005-06-13

    Disagreements on the Raman gain response of different tellurite-based glasses, measured at different wavelengths, have been recently reported in the literature. In order to resolve this controversy, a multi-wavelength Raman cross-section experiment was conducted on two different TeO2-based glass samples. The estimated Raman gain response of the material shows good agreement with the directly-measured Raman gain data at 1064 nm, after correction for the dispersion and wavelength-dependence of the Raman gain process.

  20. Measuremental analysis of thermal performance of direct gain houses in Kanto district. Effects of thermal mass and caves; Kanto chiho ni tatsu direct gain jutaku no netsuseino jissoku. Netsuyoryo to hisashi no koka

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, K; Sunaga, N; Muro, K [Tokyo Metropolitan University, Tokyo (Japan)

    1996-10-27

    The thermal performance of direct gain passive solar houses was measured. Mr. M`s two-storied RC residence with double glazing windows and thermal storage floors, walls and ceilings of brick or concrete was provided for measurement. Its double eaves of the south window and both SE and SW overhanging exterior walls play a role in sunshade. Mr. I`s two-storied wooden residence with thermal storage RC floors and brick walls, and no eaves of the south window and no overhanging exterior walls was also provided. The summer and winter measurement results were in complete contrast between the residences. In summer, large thermal mass and eaves of Mr. M`s residence were effective, while in winter, small thermal mass and no eaves of Mr. I`s residence were effective. The following ideas are important in design from the viewpoint of indoor thermal environment: a movable sunshade for taking in solar radiation as much as possible in winter, well-balanced arrangement of thermal storage parts with suitable thermal mass corresponding to movement of the sun, a large screen door for cross ventilation in summer, and a night insulation shutter for reducing heat loss in winter. 2 refs., 10 figs., 1 tab.

  1. Adaptive Fuzzy Robust Control for a Class of Nonlinear Systems via Small Gain Theorem

    Directory of Open Access Journals (Sweden)

    Xingjian Wang

    2013-01-01

    Full Text Available Practical nonlinear systems can usually be represented by partly linearizable models with unknown nonlinearities and external disturbances. Based on this consideration, we propose a novel adaptive fuzzy robust control (AFRC algorithm for such systems. The AFRC effectively combines techniques of adaptive control and fuzzy control, and it improves the performance by retaining the advantages of both methods. The linearizable part will be linearly parameterized with unknown but constant parameters, and the discontinuous-projection-based adaptive control law is used to compensate these parts. The Takagi-Sugeno fuzzy logic systems are used to approximate unknown nonlinearities. Robust control law ensures the robustness of closed-loop control system. A systematic design procedure of the AFRC algorithm by combining the backstepping technique and small-gain approach is presented. Then the closed-loop stability is studied by using small gain theorem, and the result indicates that the closed-loop system is semiglobally uniformly ultimately bounded.

  2. Low-Gain, Low-Noise Integrated Neuronal Amplifier for Implantable Artifact-Reduction Recording System

    OpenAIRE

    Zbrzeski, Adeline; Lewis, Noëlle; Rummens, Francois; Jung, Ranu; N'Kaoua, Gilles; Benazzouz, Abdelhamid; Renaud, Sylvie

    2013-01-01

    Brain neuroprostheses for neuromodulation are being designed to monitor the neural activity of the brain in the vicinity of the region being stimulated using a single macro-electrode. Using a single macro-electrode, recent neuromodulation studies show that recording systems with a low gain neuronal amplifier and successive amplifier stages can reduce or reject stimulation artifacts. These systems were made with off-the-shelf components that are not amendable for future implant design. A low-g...

  3. Longitudinal analysis of direct and indirect effects on average daily gain in rabbits using a structured antedependence model.

    Science.gov (United States)

    David, Ingrid; Sánchez, Juan-Pablo; Piles, Miriam

    2018-05-10

    Indirect genetic effects (IGE) are important components of various traits in several species. Although the intensity of social interactions between partners likely vary over time, very few genetic studies have investigated how IGE vary over time for traits under selection in livestock species. To overcome this issue, our aim was: (1) to analyze longitudinal records of average daily gain (ADG) in rabbits subjected to a 5-week period of feed restriction using a structured antedependence (SAD) model that includes IGE and (2) to evaluate, by simulation, the response to selection when IGE are present and genetic evaluation is based on a SAD model that includes IGE or not. The direct genetic variance for ADG (g/d) increased from week 1 to 3 [from 8.03 to 13.47 (g/d) 2 ] and then decreased [6.20 (g/d) 2 at week 5], while the indirect genetic variance decreased from week 1 to 4 [from 0.43 to 0.22 (g/d) 2 ]. The correlation between the direct genetic effects of different weeks was moderate to high (ranging from 0.46 to 0.86) and tended to decrease with time interval between measurements. The same trend was observed for IGE for weeks 2 to 5 (correlations ranging from 0.62 to 0.91). Estimates of the correlation between IGE of week 1 and IGE of the other weeks did not follow the same pattern and correlations were lower. Estimates of correlations between direct and indirect effects were negative at all times. After seven generations of simulated selection, the increase in ADG from selection on EBV from a SAD model that included IGE was higher (~ 30%) than when those effects were omitted. Indirect genetic effects are larger just after mixing animals at weaning than later in the fattening period, probably because of the establishment of social hierarchy that is generally observed at that time. Accounting for IGE in the selection criterion maximizes genetic progress.

  4. Information sensitivity functions to assess parameter information gain and identifiability of dynamical systems.

    Science.gov (United States)

    Pant, Sanjay

    2018-05-01

    A new class of functions, called the 'information sensitivity functions' (ISFs), which quantify the information gain about the parameters through the measurements/observables of a dynamical system are presented. These functions can be easily computed through classical sensitivity functions alone and are based on Bayesian and information-theoretic approaches. While marginal information gain is quantified by decrease in differential entropy, correlations between arbitrary sets of parameters are assessed through mutual information. For individual parameters, these information gains are also presented as marginal posterior variances, and, to assess the effect of correlations, as conditional variances when other parameters are given. The easy to interpret ISFs can be used to (a) identify time intervals or regions in dynamical system behaviour where information about the parameters is concentrated; (b) assess the effect of measurement noise on the information gain for the parameters; (c) assess whether sufficient information in an experimental protocol (input, measurements and their frequency) is available to identify the parameters; (d) assess correlation in the posterior distribution of the parameters to identify the sets of parameters that are likely to be indistinguishable; and (e) assess identifiability problems for particular sets of parameters. © 2018 The Authors.

  5. A temperature-dependent gain control system for improving the stability of Si-PM-based PET systems

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Satomi, Junkichi; Watabe, Tadashi; Imaizumi, Masao; Shimosegawa, Eku; Hatazawa, Jun; Watabe, Hiroshi; Kanai, Yasukazu

    2011-01-01

    The silicon-photomultiplier (Si-PM) is a promising photodetector for the development of new PET systems due to its small size, high gain and relatively low sensitivity to the static magnetic field. One drawback of the Si-PM is that it has significant temperature-dependent gain that poses a problem for the stability of the Si-PM-based PET system. To reduce this problem, we developed and tested a temperature-dependent gain control system for the Si-PM-based PET system. The system consists of a thermometer, analog-to-digital converter, personal computer, digital-to-analog converter and variable gain amplifiers in the weight summing board of the PET system. Temperature characteristics of the Si-PM array are measured and the calculated correction factor is sent to the variable gain amplifier. Without this correction, the temperature-dependent peak channel shifts of the block detector were -55% from 20 deg. C to 35 deg.C. With the correction, the peak channel variations were corrected within ±8%. The coincidence count rate of the Si-PM-based PET system was measured using a Na-22 point source while monitoring the room temperature. Without the correction, the count rate inversely changed with the room temperature by 10% for 1.5 deg. C temperature changes. With the correction, the count rate variation was reduced to within 3.7%. These results indicate that the developed temperature-dependent gain control system can contribute to improving the stability of Si-PM-based PET systems.

  6. Synchronization and secure communication of chaotic systems via robust adaptive high-gain fuzzy observer

    International Nuclear Information System (INIS)

    Hyun, Chang-Ho; Park, Chang-Woo; Kim, Jae-Hun; Park, Mignon

    2009-01-01

    This paper proposes an alternative robust adaptive high-gain fuzzy observer design scheme and its application to synchronization and secure communication of chaotic systems. It is assumed that their states are immeasurable and their parameters are unknown. The structure of the proposed observer is represented by Takagi-Sugeno fuzzy model and has the integrator of the estimation error. It improves the performance of high-gain observer and makes the proposed observer robust against noisy measurements, uncertainties and parameter perturbations as well. Using Lyapunov stability theory, an adaptive law is derived to estimate the unknown parameters and the stability of the proposed observer is analyzed. Some simulation result of synchronization and secure communication of chaotic systems is given to present the validity of theoretical derivations and the performance of the proposed observer as an application.

  7. Absolute gain calibration system for the 349-pixel imaging element of the tactic telescope array

    International Nuclear Information System (INIS)

    Tickoo, A.K.; Dhar, V.K.; Venugopal, K.; Kaul, S.K.; Koul, R.; Bhatt, N.; Goyal, H.C.; Bhat, C.L.

    2001-01-01

    The imaging Element of the 4-element TACTIC telescope array has been in operation at Mt. Abu since 1997, for carrying detailed investigations of gamma-ray sources in the TeV energy range. In order to characterize the progenitor particle (Gamma-ray/cosmic-ray), a relative gain calibration system, based on a high intensity LED, has been in operation. However, for calorimetric purposes, an absolute gain calibration system is necessary and has been developed for an on-line calibration of 4 out of 349-pixels of its imaging camera, using 241 Am based light pulsers. The details of the experimental set-up and the results obtained so far are presented in this paper. (author)

  8. Some new directions in system transient simulation

    International Nuclear Information System (INIS)

    Ransom, V.H.

    1986-01-01

    The current research in system transient simulation at the Idaho National Engineering Laboratory (INEL) is summarized in this paper and three new directions that are emerging from this work are discussed. The new directions are: development of an Advanced Thermal Hydraulic Energy Network Analyzer (ATHENA) having new modeling capability, use of expert systems for enhancing simulation methods, and the trend to individual workstations for simulation

  9. Initial experience gained with the balance-group system of the Swiss power supply legislation

    International Nuclear Information System (INIS)

    Waldner, M.; Rechsteiner, S.

    2010-01-01

    This article takes a look at the initial experience gained with the Swiss balance-group system. This system was introduced within the framework of Swiss power supply legislation (StromVG - Stromversorgungsgesetz). The balance-group system was considered to be an essential precondition for the implementation of an energy trading business in a liberalised power market. The associated rights and responsibilities and the economic risks involved are discussed in detail. The partners and structures involved in such a balance-group are looked at and basic models for the associated contracts are examined. The relationship between balance-groups and the national power grid Swissgrid are discussed

  10. Low-Gain, Low-Noise Integrated Neuronal Amplifier for Implantable Artifact-Reduction Recording System

    Directory of Open Access Journals (Sweden)

    Abdelhamid Benazzouz

    2013-09-01

    Full Text Available Brain neuroprostheses for neuromodulation are being designed to monitor the neural activity of the brain in the vicinity of the region being stimulated using a single macro-electrode. Using a single macro-electrode, recent neuromodulation studies show that recording systems with a low gain neuronal amplifier and successive amplifier stages can reduce or reject stimulation artifacts. These systems were made with off-the-shelf components that are not amendable for future implant design. A low-gain, low-noise integrated neuronal amplifier (NA with the capability of recording local field potentials (LFP and spike activity is presented. In vitro and in vivo characterizations of the tissue/electrode interface, with equivalent impedance as an electrical model for recording in the LFP band using macro-electrodes for rodents, contribute to the NA design constraints. The NA occupies 0.15 mm2 and dissipates 6.73 µW, and was fabricated using a 0.35 µm CMOS process. Test-bench validation indicates that the NA provides a mid-band gain of 20 dB and achieves a low input-referred noise of 4 µVRMS. Ability of the NA to perform spike recording in test-bench experiments is presented. Additionally, an awake and freely moving rodent setup was used to illustrate the integrated NA ability to record LFPs, paving the pathway for future implantable systems for neuromodulation.

  11. A Vehicle Haptic Steering by Wire System Based on High Gain GPI Observers

    Directory of Open Access Journals (Sweden)

    A. Rodriguez-Angeles

    2014-01-01

    Full Text Available A vehicle steering by wire (SBW haptic system based on high gain generalized proportional integral (GPI observers is introduced. The observers are considered for the estimation of dynamic perturbations that are present at the tire and steering wheel. To ensure efficient tracking between the commanded steering wheel angle and the tire orientation angle, the estimated perturbations are on line canceled. As to provide a haptic interface with the driver, the estimated dynamic effects at the steering rack are fed back to the steering wheel, yielding a master-slave haptic system with bilateral communication. For implementation purposes few sensors and minimum knowledge of the dynamic model are required, which is a major advantage compared to other approaches. Only position tracking errors are fed back, while all other signals are estimated by the high gain GPI observers. The scheme is robust to uncertainty on the input gain and cancels dynamic perturbation effects such as friction and aligning forces on the tire. Experimental results are presented on a prototype platform.

  12. Robust control for spacecraft rendezvous system with actuator unsymmetrical saturation: a gain scheduling approach

    Science.gov (United States)

    Wang, Qian; Xue, Anke

    2018-06-01

    This paper has proposed a robust control for the spacecraft rendezvous system by considering the parameter uncertainties and actuator unsymmetrical saturation based on the discrete gain scheduling approach. By changing of variables, we transform the actuator unsymmetrical saturation control problem into a symmetrical one. The main advantage of the proposed method is improving the dynamic performance of the closed-loop system with a region of attraction as large as possible. By the Lyapunov approach and the scheduling technology, the existence conditions for the admissible controller are formulated in the form of linear matrix inequalities. The numerical simulation illustrates the effectiveness of the proposed method.

  13. High Gain Antenna System Deployment Mechanism Integration, Characterization, and Lessons Learned

    Science.gov (United States)

    Parong, Fil; Russell, Blair; Garcen, Walter; Rose, Chris; Johnson, Chris; Huber, Craig

    2014-01-01

    The integration and deployment testing of the High Gain Antenna System for the Global Precipitation Measurement mission is summarized. The HGAS deployment mechanism is described. The gravity negation system configuration and its influence on vertical, ground-based, deployment tests are presented with test data and model predictions. A focus is made on the late discovery and resolution of a potentially mission degrading deployment interference condition. The interaction of the flight deployment mechanism, gravity negation mechanism, and use of dynamic modeling is described and lessons learned presented.

  14. Experience Gained on Direct Use of Low Enthalpy Energy in Hotel do Parque, S. Pedro do Sul, Portugal

    Science.gov (United States)

    Ferreira Gomes, L. M.; Neves Trota, A. P.; Reis Afonso de Albuquerque, F. J.

    2017-12-01

    Despite the high number of thermal flowing springs in Portugal mainland (up to 52 hot springs), ranging temperatures from 20 °C to 77 °C, and with significant water flow rate, few district heating system were implemented in Portugal. Here we present the São Pedro do Sul district heating system, located northern of Portugal. The thermal power plant was designed, completed, and commissioned in 2001 allowing the utilization of the geothermal heat by local users, as Hotel do Parque. The district heating system sums about 15 years of utilization without interruption and with minor drawbacks. On this paper we present the project overview along with thermal power plant specifications and data numbers. Heat comes from a 16.9 L/s of thermal water supplied by a natural spring and a nearby well. Heat from the spring and well sources is transferred to a secondary low mineralized water system by a plate heat exchanger, allowing the heating of space and domestic waters of hotel areas. Based on a theoretically cascade direct use of heat from a 67 °C to a 20 °C water temperature range, available heat totals 29.1*106 kWh yearly. However, past and actual use of heat only reaches around 1.6% of that figure. By comparing with fossil heat sources, actual use of a natural heat source reduces a theoretically amount of 117.9 ton of CO2 emissions by year. The successful use of this district heating system can promote local expansion of new users and other possible heat uses of this renewable energy, giving chance for the district heating system saturation.

  15. Adaptive resource allocation scheme using sliding window subchannel gain computation: context of OFDMA wireless mobiles systems

    International Nuclear Information System (INIS)

    Khelifa, F.; Samet, A.; Ben Hassen, W.; Afif, M.

    2011-01-01

    Multiuser diversity combined with Orthogonal Frequency Division Multiple Access (OFDMA) are a promising technique for achieving high downlink capacities in new generation of cellular and wireless network systems. The total capacity of OFDMA based-system is maximized when each subchannel is assigned to the mobile station with the best channel to noise ratio for that subchannel with power is uniformly distributed between all subchannels. A contiguous method for subchannel construction is adopted in IEEE 802.16 m standard in order to reduce OFDMA system complexity. In this context, new subchannel gain computation method, can contribute, jointly with optimal assignment subchannel to maximize total system capacity. In this paper, two new methods have been proposed in order to achieve a better trade-off between fairness and efficiency use of resources. Numerical results show that proposed algorithms provide low complexity, higher total system capacity and fairness among users compared to others recent methods.

  16. Herdable Systems Over Signed, Directed Graphs

    KAUST Repository

    Ruf, Sebastian F.

    2018-04-11

    This paper considers the notion of herdability, a set-based reachability condition, which asks whether the state of a system can be controlled to be element-wise larger than a non-negative threshold. The basic theory of herdable systems is presented, including a necessary and sufficient condition for herdability. This paper then considers the impact of the underlying graph structure of a linear system on the herdability of the system, for the case where the graph is represented as signed and directed. By classifying nodes based on the length and sign of walks from an input, we find a class of completely herdable systems as well as provide a complete characterization of nodes that can be herded in systems with an underlying graph that is a directed out-branching rooted at a single input.

  17. Herdable Systems Over Signed, Directed Graphs

    KAUST Repository

    Ruf, Sebastian F.; Egerstedt, Magnus; Shamma, Jeff S.

    2018-01-01

    This paper considers the notion of herdability, a set-based reachability condition, which asks whether the state of a system can be controlled to be element-wise larger than a non-negative threshold. The basic theory of herdable systems is presented, including a necessary and sufficient condition for herdability. This paper then considers the impact of the underlying graph structure of a linear system on the herdability of the system, for the case where the graph is represented as signed and directed. By classifying nodes based on the length and sign of walks from an input, we find a class of completely herdable systems as well as provide a complete characterization of nodes that can be herded in systems with an underlying graph that is a directed out-branching rooted at a single input.

  18. Novel robotic systems and future directions

    Directory of Open Access Journals (Sweden)

    Ki Don Chang

    2018-01-01

    Full Text Available Robot-assistance is increasingly used in surgical practice. We performed a nonsystematic literature review using PubMed/MEDLINE and Google for robotic surgical systems and compiled information on their current status. We also used this information to predict future about the direction of robotic systems based on various robotic systems currently being developed. Currently, various modifications are being made in the consoles, robotic arms, cameras, handles and instruments, and other specific functions (haptic feedback and eye tracking that make up the robotic surgery system. In addition, research for automated surgery is actively being carried out. The development of future robots will be directed to decrease the number of incisions and improve precision. With the advent of artificial intelligence, a more practical form of robotic surgery system can be introduced and will ultimately lead to the development of automated robotic surgery system.

  19. Operational experience gained with the failed fuel rod detection system in nuclear power plants

    International Nuclear Information System (INIS)

    Boehm, H.H.; Forch, H.

    1985-01-01

    Brown Boveri Reaktor GmbH together with Krautkramer Company developed such a FAILED FUEL ROD DETECTION SYSTEM (FFRDS) which allows to located defective fuel rods without dismantling the fuel assembly or pulling of individual rods. Since 1979 the FFRDS is employed successfully in various nuclear power plants in Europe, USA, Japan, and Korea. The short inspection time and the high reliability of the method make the FFRDS a true competitor to the sipping method. In this paper the authors discuss the method and the design of the system, the equipment set-up, its features and the experience gained so far. The system has been performed and automated to such an extent that within a short installation period series of fuel assemblies can be tested with relatively short intervals of time (5 minutes for BWR and 7 minutes for PWR fuel assemblies per side). The ability of the system for deployment under various conditions and the experience gained during the past six years have made this system universally applicable and highly sensitive to the requirements of NDT during outages and for transport of FAs to intermediate storage facilities. Comparison of FFRDS to conventional sipping has indicated in several instances that the FFRDS is superior to the latter technique

  20. Method of steering the gain of a multiple antenna global positioning system receiver

    Science.gov (United States)

    Evans, Alan G.; Hermann, Bruce R.

    1992-06-01

    A method for steering the gain of a multiple antenna Global Positioning System (GPS) receiver toward a plurality of a GPS satellites simultaneously is provided. The GPS signals of a known wavelength are processed digitally for a particular instant in time. A range difference or propagation delay between each antenna for GPS signals received from each satellite is first resolved. The range difference consists of a fractional wavelength difference and an integer wavelength difference. The fractional wavelength difference is determined by each antenna's tracking loop. The integer wavelength difference is based upon the known wavelength and separation between each antenna with respect to each satellite position. The range difference is then used to digitally delay the GPS signals at each antenna with respect to a reference antenna. The signal at the reference antenna is then summed with the digitally delayed signals to generate a composite antenna gain. The method searches for the correct number of integer wavelengths to maximize the composite gain. The range differences are also used to determine the attitude of the array.

  1. A programmable gain amplifier with a DC offset calibration loop for a direct-conversion WLAN transceiver

    Energy Technology Data Exchange (ETDEWEB)

    Lei Qianqian; Chen Zhiming [Department of Applied Electronics, Xi' an University of Technology, Xi' an 710048 (China); Lin Min; Shi Yin, E-mail: leiqianqian@163.com [Suzhou-CAS Semiconductors Integrated Technology Research Center, Suzhou 215021 (China)

    2011-04-15

    A high-linearity PGA (programmable gain amplifier) with a DC offset calibration loop is proposed. The PGA adopts a differential degeneration structure to vary voltage gain and uses the closed-loop structure including the input op-amps to enhance the linearity. A continuous time feedback based DC offset calibration loop is also designed to solve the DC offset problem. This PGA is fabricated by TSMC 0.13 {mu}m CMOS technology. The measurements show that the receiver PGA (RXPGA) provides a 64 dB gain range with a step of 1 dB, and the transmitter PGA (TXPGA) covers a 16 dB gain. The RXPGA consumes 18 mA and the TXPGA consumes 7 mA (I and Q path) under a 3.3 V supply. The bandwidth of the multi-stage PGA is higher than 20 MHz. In addition, the DCOC (DC offset cancellation) circuit shows 10 kHz of HPCF (high pass cutoff frequency) and the DCOC settling time is less than 0.45 {mu}s. (semiconductor integrated circuits)

  2. Coaxial direct-detection lidar-system

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to a coaxial direct-detection LIDAR system for measuring velocity, temperature and/or particulate density. The system comprises a laser source for emitting a laser light beam having a lasing center frequency along an emission path. The system further comprises an optical....... Finally, the system comprises a detector system arranged to receive the return signal from the optical delivery system, the detector system comprising a narrowband optical filter and a detector, the narrowband optical filter having a filter center frequency of a pass-band, wherein the center lasing...... frequency and/or the center filter frequency may be scanned. The invention further relates to an aircraft airspeed measurement device, and a wind turbine airspeed measurement device comprising the LIDAR system....

  3. Switched-Observer-Based Adaptive Neural Control of MIMO Switched Nonlinear Systems With Unknown Control Gains.

    Science.gov (United States)

    Long, Lijun; Zhao, Jun

    2017-07-01

    In this paper, the problem of adaptive neural output-feedback control is addressed for a class of multi-input multioutput (MIMO) switched uncertain nonlinear systems with unknown control gains. Neural networks (NNs) are used to approximate unknown nonlinear functions. In order to avoid the conservativeness caused by adoption of a common observer for all subsystems, an MIMO NN switched observer is designed to estimate unmeasurable states. A new switched observer-based adaptive neural control technique for the problem studied is then provided by exploiting the classical average dwell time (ADT) method and the backstepping method and the Nussbaum gain technique. It effectively handles the obstacle about the coexistence of multiple Nussbaum-type function terms, and improves the classical ADT method, since the exponential decline property of Lyapunov functions for individual subsystems is no longer satisfied. It is shown that the technique proposed is able to guarantee semiglobal uniformly ultimately boundedness of all the signals in the closed-loop system under a class of switching signals with ADT, and the tracking errors converge to a small neighborhood of the origin. The effectiveness of the approach proposed is illustrated by its application to a two inverted pendulum system.

  4. New Directions in Modeling the Lighting Systems

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2004-12-01

    Full Text Available This paper presents information about new directions in the modelingof lighting systems, and an overview of methods for the modeling oflighting systems. The new R-FEM method is described, which is acombination of the Radiosity method and the Finite Elements Method. Thepaper contains modeling results and their verification by experimentalmeasurements and by the Matlab simulation for this R-FEM method.

  5. Study on the drive laser system of the photocathode-injector used in high gain FEL

    CERN Document Server

    Lu Xiang Yang; Zhao Kui; Wang Li; Quan Sheng Wen; Hao Jian Kui; Zhang Bao Cheng; Chen J

    2002-01-01

    High gain FEL requires high quality electron beam which can be provided only by the RF photocathode gun. The drive laser for electron source plays the key role. In Institute of Heavy Ion Physics of Beijing University, the laser system is required to deliver a 500 mu J, 6-8 ps pulse of UV photons (260 nm) to the cathode. This system mainly consists of a CW, frequency-doubled, diode-pumped Nd:YAG laser, which provides energy to pump a CW mode-locked Ti:sapphire oscillator, Q-switched Nd:YaG pump lasers, a regenerative amplifier and harmonics crystals. To meet the low jitters of pulses (1.0 ps), cavity length of the oscillator should be adjustable to lock the pulse frequency with external RF reference, and a phase stability feedback system is also used

  6. Gain factors with the new supermirror guide system at the Budapest Neutron Centre

    International Nuclear Information System (INIS)

    Rosta, L.; Cser, L.; Revay, Z.

    2002-01-01

    In parallel with the installation of a cold-neutron source (CNS) at the 10-MW Budapest Research Reactor, the neutron-guide system has been redesigned and replaced by state of art neutron optical elements. Monte Carlo calculations have been used to determine the optimal conditions for the guide parameters. For the three cold-neutron beams nearly 100 m of new guides were installed; a great part is made of supermirrors. The new in-pile guide system and the individual shutters enable minimal losses at the starting sections. The out-of-pile part was optimized for the experimental stations. The neutron-flux measurements were compared with the simulated values. The combined effect of the CNS and the guide system yields a gain factor in the flux as high as 30-60. (orig.)

  7. Experience gained at the NEA Data Bank with a commercial data base management system

    International Nuclear Information System (INIS)

    Johnson, D.; Pellegrino, L.; Schuler, W.; Tubbs, N.

    1981-01-01

    The Nuclear Energy Agency Data Bank of the OECD has recently converted the computer storage of large numerical and bibliographic files to a commecial data base management system (DBMS). Such systems are relatively new in scientific use, but they are well-developed and are widely applied in commercial and industrial environments. This application is of particular interest in that it involves scientific information and the size of the data approaches what is feasible with a DBMS on a small computer. In this paper, the experience gained throughout the project is documented for the benefit of others who way be contemplating a similar application. Some of the points considered with be specific to this actual base and to the system used, but the paper also contains much information of general interest. Our viewpoint is that of applications software developers with limited previous DBMS experience and the emphasis is on the practical details of establishing a CODASYL-type data base

  8. Multiple Drosophila Tracking System with Heading Direction

    Directory of Open Access Journals (Sweden)

    Pudith Sirigrivatanawong

    2017-01-01

    Full Text Available Machine vision systems have been widely used for image analysis, especially that which is beyond human ability. In biology, studies of behavior help scientists to understand the relationship between sensory stimuli and animal responses. This typically requires the analysis and quantification of animal locomotion. In our work, we focus on the analysis of the locomotion of the fruit fly D r o s o p h i l a m e l a n o g a s t e r , a widely used model organism in biological research. Our system consists of two components: fly detection and tracking. Our system provides the ability to extract a group of flies as the objects of concern and furthermore determines the heading direction of each fly. As each fly moves, the system states are refined with a Kalman filter to obtain the optimal estimation. For the tracking step, combining information such as position and heading direction with assignment algorithms gives a successful tracking result. The use of heading direction increases the system efficiency when dealing with identity loss and flies swapping situations. The system can also operate with a variety of videos with different light intensities.

  9. Robust Model Predictive Control of a Nonlinear System with Known Scheduling Variable and Uncertain Gain

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

    2012-01-01

    Robust model predictive control (RMPC) of a class of nonlinear systems is considered in this paper. We will use Linear Parameter Varying (LPV) model of the nonlinear system. By taking the advantage of having future values of the scheduling variable, we will simplify state prediction. Because...... of the special structure of the problem, uncertainty is only in the B matrix (gain) of the state space model. Therefore by taking advantage of this structure, we formulate a tractable minimax optimization problem to solve robust model predictive control problem. Wind turbine is chosen as the case study and we...... choose wind speed as the scheduling variable. Wind speed is measurable ahead of the turbine, therefore the scheduling variable is known for the entire prediction horizon....

  10. Almost output regulation of LFT systems via gain-scheduling control

    Science.gov (United States)

    Yuan, Chengzhi; Duan, Chang; Wu, Fen

    2018-05-01

    Output regulation of general uncertain systems is a meaningful yet challenging problem. In spite of the rich literature in the field, the problem has not yet been addressed adequately due to the lack of an effective design mechanism. In this paper, we propose a new design framework for almost output regulation of uncertain systems described in the general form of linear fractional transformation (LFT) with time-varying parametric uncertainties and unknown external perturbations. A novel semi-LFT gain-scheduling output regulator structure is proposed, such that the associated control synthesis conditions guaranteeing both output regulation and ? disturbance attenuation performance are formulated as a set of linear matrix inequalities (LMIs) plus parameter-dependent linear matrix equations, which can be solved separately. A numerical example has been used to demonstrate the effectiveness of the proposed approach.

  11. Direct current power delivery system and method

    Science.gov (United States)

    Zhang, Di; Garces, Luis Jose; Dai, Jian; Lai, Rixin

    2016-09-06

    A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component.

  12. Frequency domain design of gain scheduling control for large wind systems in full-load region

    International Nuclear Information System (INIS)

    Burlibaşa, A.; Ceangă, E.

    2014-01-01

    Highlights: • A large wind energy system, operating under full-load regime, is considered. • According to its particularities in frequency domain, control law design is provided. • These particularities are influenced by the interactions of wind–tower–blade ensemble. • Control low, within gain scheduling strategy, is achieved imposing stability reserve. • Supplementary a criterion, aimed at reducing mechanical loads, is imposed. - Abstract: The paper presents the issue of power control law synthesis, in the case of a large wind system that operates under full-load regime, based on dynamic properties details in frequency domain. Solving this problem involves two phases: the establishment of a linearized model as faithfully as possible in various operating points of the full-load region, and synthesis of the power controller, considered with classic structure, taking into account frequency particularities of the obtained linearized model. Obtained linear model of the controlled process is of order 16 and encloses subsystems for tower fore-aft oscillations damping, and for drive-train torsion oscillations damping. The designed controller contains a PI component and a lag compensator for dynamic correction at high frequencies. It is known that the main features of wind system dynamics generated by the interaction of wind–tower–blade ensemble cause a gap in the gain characteristic of the model and complex conjugate zeros, which can move between right and left half-planes, depending on the average wind speed value. Consequently, for control law synthesis an interactive frequency solution is adopted. This is “transparent” in relation to particularities induced by wind–tower–blade interaction. This solution allows evaluation of the extent to which control law is affected by the subsystem for tower oscillations damping. Given the strong dependence between the model and the mean wind speed value, a gain scheduling control law is designed. At

  13. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m-1 was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain ratio

  14. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions.

    Science.gov (United States)

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m(-1) was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain

  15. Maximum Wind Power Tracking of Doubly Fed Wind Turbine System Based on Adaptive Gain Second-Order Sliding Mode

    Directory of Open Access Journals (Sweden)

    Hongchang Sun

    2018-01-01

    Full Text Available This paper proposes an adaptive gain second-order sliding mode control strategy to track optimal electromagnetic torque and regulate reactive power of doubly fed wind turbine system. Firstly, wind turbine aerodynamic characteristics and doubly fed induction generator (DFIG modeling are presented. Then, electromagnetic torque error and reactive power error are chosen as sliding variables, and fixed gain super-twisting sliding mode control scheme is designed. Considering that uncertainty upper bound is unknown and is hard to be estimated in actual doubly fed wind turbine system, a gain scheduled law is proposed to compel control parameters variation according to uncertainty upper bound real-time. Adaptive gain second-order sliding mode rotor voltage control method is constructed in detail and finite time stability of doubly fed wind turbine control system is strictly proved. The superiority and robustness of the proposed control scheme are finally evaluated on a 1.5 MW DFIG wind turbine system.

  16. Detection Thresholds for Rotation and Translation Gains in 360° Video-Based Telepresence Systems.

    Science.gov (United States)

    Zhang, Jingxin; Langbehn, Eike; Krupke, Dennis; Katzakis, Nicholas; Steinicke, Frank

    2018-04-01

    Telepresence systems have the potential to overcome limits and distance constraints of the real-world by enabling people to remotely visit and interact with each other. However, current telepresence systems usually lack natural ways of supporting interaction and exploration of remote environments (REs). In particular, single webcams for capturing the RE provide only a limited illusion of spatial presence, and movement control of mobile platforms in today's telepresence systems are often restricted to simple interaction devices. One of the main challenges of telepresence systems is to allow users to explore a RE in an immersive, intuitive and natural way, e.g., by real walking in the user's local environment (LE), and thus controlling motions of the robot platform in the RE. However, the LE in which the user's motions are tracked usually provides a much smaller interaction space than the RE. In this context, redirected walking (RDW) is a very suitable approach to solve this problem. However, so far there is no previous work, which explored if and how RDW can be used in video-based 360° telepresence systems. In this article, we conducted two psychophysical experiments in which we have quantified how much humans can be unknowingly redirected on virtual paths in the RE, which are different from the physical paths that they actually walk in the LE. Experiment 1 introduces a discrimination task between local and remote translations, and in Experiment 2 we analyzed the discrimination between local and remote rotations. In Experiment 1 participants performed straightforward translations in the LE that were mapped to straightforward translations in the RE shown as 360° videos, which were manipulated by different gains. Then, participants had to estimate if the remotely perceived translation was faster or slower than the actual physically performed translation. Similarly, in Experiment 2 participants performed rotations in the LE that were mapped to the virtual rotations

  17. Genomics of Systemic Lupus Erythematosus: Insights Gained by Studying Monogenic Young-Onset Systemic Lupus Erythematosus.

    Science.gov (United States)

    Hiraki, Linda T; Silverman, Earl D

    2017-08-01

    Systemic lupus erythematosus (SLE) is a systemic, autoimmune, multisystem disease with a heterogeneous clinical phenotype. Genome-wide association studies have identified multiple susceptibility loci, but these explain a fraction of the estimated heritability. This is partly because within the broad spectrum of SLE are monogenic diseases that tend to cluster in patients with young age of onset, and in families. This article highlights insights into the pathogenesis of SLE provided by these monogenic diseases. It examines genetic causes of complement deficiency, abnormal interferon production, and abnormalities of tolerance, resulting in monogenic SLE with overlapping clinical features, autoantibodies, and shared inflammatory pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Targeting the maximum heat recovery for systems with heat losses and heat gains

    International Nuclear Information System (INIS)

    Wan Alwi, Sharifah Rafidah; Lee, Carmen Kar Mun; Lee, Kim Yau; Abd Manan, Zainuddin; Fraser, Duncan M.

    2014-01-01

    Graphical abstract: Illustration of heat gains and losses from process streams. - Highlights: • Maximising energy savings through heat losses or gains. • Identifying location where insulation can be avoided. • Heuristics to maximise heat losses or gains. • Targeting heat losses or gains using the extended STEP technique and HEAT diagram. - Abstract: Process Integration using the Pinch Analysis technique has been widely used as a tool for the optimal design of heat exchanger networks (HENs). The Composite Curves and the Stream Temperature versus Enthalpy Plot (STEP) are among the graphical tools used to target the maximum heat recovery for a HEN. However, these tools assume that heat losses and heat gains are negligible. This work presents an approach that considers heat losses and heat gains during the establishment of the minimum utility targets. The STEP method, which is plotted based on the individual, as opposed to the composite streams, has been extended to consider the effect of heat losses and heat gains during stream matching. Several rules to guide the proper location of pipe insulation, and the appropriate procedure for stream shifting have been introduced in order to minimise the heat losses and maximise the heat gains. Application of the method on two case studies shows that considering heat losses and heat gains yield more realistic utility targets and help reduce both the insulation capital cost and utility cost of a HEN

  19. A new reactor core monitoring system. First experience gained at the Dukovany NPP

    International Nuclear Information System (INIS)

    Pecka, M.; Svarny, J.; Kment, J.

    2001-01-01

    The article deals with methods of interpretation of in-core measurements that are based on the determination of the three-dimensional (3D) power distribution within the reactor core, discusses on-line mode calculations, and describes the results obtained during the trial operation of the new SCORPIO-VVER reactor core monitoring system. The principles of the method of determination of the fuel assembly subchannel parameters are outlined. Alternative methods of self-powered detector signal conversion to local power are given, and some results of their testing are presented. Emphasis is put on self-powered detectors supplied by the US firm IST, which were first deployed at the Dukovany NPP in 1998. The predictive function of the SCORPIO-VVER system, whose implementation was inspired by favourable experience gained on some PWR reactors (such as the products of the Halden reactor project at Ringhals and Sizewell B) were adapted to the specific needs of WWER-440 reactors. The main results of validation of the functions are described and presented in detail. (author)

  20. Halo scraper/direct converter system study

    International Nuclear Information System (INIS)

    Luzzi, T.; Clarkson, I.; Barr, W.; Neef, W.

    1985-01-01

    During the first year of the LLNL Minimars program, a system study was undertaken to determine the most efficient method for recovery of the end cell thermal energy. The goal of the study was to recovery energy at the highest possible coolant temperature and therefore at the highest thermal efficiency. Two types of coolant were considered, water and gaseous helium. In a system study where the goal is to recover maximum thermal power in an economically designed device, it is necessary to place constraints on the design. The four constraints for the direct converter are somewhat conflicting in that a particularly design solution satisfying one may lead to an unacceptable solution for another. The final design choice must be a compromise that satisfies all the constraints

  1. A Dynamical System Exhibits High Signal-to-noise Ratio Gain by Stochastic Resonance

    Science.gov (United States)

    Makra, Peter; Gingl, Zoltan

    2003-05-01

    On the basis of mixed-signal simulations, we demonstrate that signal-to-noise ratio (SNR) gains much greater than unity can be obtained in the double-well potential through stochastic resonance (SR) with a symmetric periodic pulse train as deterministic and Gaussian white noise as random excitation. We also show that significant SNR improvement is possible in this system even for a sub-threshold sinusoid input if, instead of the commonly used narrow-band SNR, we apply an equally simple but much more realistic wide-band SNR definition. Using the latter result as an argument, we draw attention to the fact that the choice of the measure to reflect signal quality is critical with regard to the extent of signal improvement observed, and urge reconsideration of the practice prevalent in SR studies that most often the narrow-band SNR is used to characterise SR. Finally, we pose some questions concerning the possibilities of applying SNR improvement in practical set-ups.

  2. Respiratory system loop gain in normal men and women measured with proportional-assist ventilation.

    Science.gov (United States)

    Wellman, Andrew; Malhotra, Atul; Fogel, Robert B; Edwards, Jill K; Schory, Karen; White, David P

    2003-01-01

    We hypothesized that increased chemical control instability (CCI) in men could partially explain the male predominance in obstructive sleep apnea (OSA). CCI was assessed by sequentially increasing respiratory control system loop gain (LG) with proportional-assist ventilation (PAV) in 10 men (age 24-48 yr) and 9 women (age 22-36 yr) until periodic breathing or awakening occurred. Women were studied in both the follicular and luteal phases of the menstrual cycle. The amount by which PAV amplified LG was quantified from the tidal volume amplification factor [(VtAF) assisted tidal volume/unassisted tidal volume]. LG was calculated as the inverse of the VtAF occurring at the assist level immediately preceding the emergence of periodic breathing (when LG x VtAF = 1). Only 1 of 10 men and 2 of 9 women developed periodic breathing with PAV. The rest were resistant to periodic breathing despite moderately high levels of PAV amplification. We conclude that LG is low in the majority of normal men and women and that higher volume amplification factors are needed to determine whether gender differences exist in this low range.

  3. Unified Performance Analysis of Mixed Line of Sight RF-FSO Fixed Gain Dual-Hop Transmission Systems

    KAUST Repository

    Zedini, Emna

    2014-04-03

    In the work, we carry out a unified performance analysis of a dual-hop fixed gain relay system over asymmetric links composed of both radio-frequency (RF) and unified free- space optics (FSO) under the effect of pointing errors. The RF link is modeled by the Nakagami-m fading channel and the FSO link by the Gamma-Gamma fading channel subject to both types of detection techniques (i.e. heterodyne detection and intensity modulation with direct detection (IM/DD)). In particular, we derive new unified closed-form expressions for the cumulative distribution function, the probability density function, the moment generation function, and the moments of the end-to-end signal-to-noise ratio of these systems in terms of the Meijer’s G function. Based on these formulas, we offer exact closed-form expressions for the outage probability, the higher-order amount of fading, and the average bit-error rate of a variety of binary modulations in terms of the Meijer’s G function. Further, an exact closed-form expression for the end-to-end ergodic capacity for the Nakagami-m-unified FSO relay links is derived in terms of the bivariate G function. All the given results are verified via Computer-based Monte-Carlo simulations.

  4. A high speed dual-gain preamplifier system with multiple channels

    International Nuclear Information System (INIS)

    Zhao Lei; Liu Shubin; Xian Ze; An Qi

    2008-01-01

    In this paper, a multiple-channel high speed preamplifier module with dual-gain is presented, together with its design principle, test methods and performance parameter. By proper choice of the chips and careful circuit design, the preamplifier accomplishes a fine performance in high speed analog signal processing. The 3 dB bandwidth is above 440 MHz for gain factor of 2 and 280 MHz for gain factor of 8, with the leading edge time of less than 2 ns. The preamplifier module has been used in the research project of β-delayed neutron emission of radionuclides in neutron-rich region. (authors)

  5. Comparison of vertical hydraulic conductivity in a streambed-point bar system of a gaining stream

    Science.gov (United States)

    Dong, Weihong; Chen, Xunhong; Wang, Zhaowei; Ou, Gengxin; Liu, Can

    2012-07-01

    SummaryVertical hydraulic conductivities (Kv) of both streambed and point bars can influence water and solute exchange between streams and surrounding groundwater systems. The sediments in point bars are relatively young compared to the older sediments in the adjacent aquifers but slightly older compared to submerged streambeds. Thus, the permeability in point bar sediments can be different not only from regional aquifer but also from modern streambed. However, there is a lack of detailed studies that document spatial variability of vertical hydraulic conductivity in point bars of meandering streams. In this study, the authors proposed an in situ permeameter test method to measure vertical hydraulic conductivity of the two point bars in Clear Creek, Nebraska, USA. We compared the Kv values in streambed and adjacent point bars through 45 test locations in the two point bars and 51 test locations in the streambed. The Kv values in the point bars were lower than those in the streambed. Kruskal-Wallis test confirmed that the Kv values from the point bars and from the channel came from two statistically different populations. Within a point bar, the Kv values were higher along the point bar edges than those from inner point bars. Grain size analysis indicated that slightly more silt and clay particles existed in sediments from inner point bars, compared to that from streambed and from locations near the point bar edges. While point bars are the deposits of the adjacent channel, the comparison of two groups of Kv values suggests that post-depositional processes had an effect on the evolution of Kv from channel to point bars in fluvial deposits. We believed that the transport of fine particles and the gas ebullition in this gaining stream had significant effects on the distribution of Kv values in a streambed-point bar system. With the ageing of deposition in a floodplain, the permeability of point bar sediments can likely decrease due to reduced effects of the upward

  6. On the performance of hybrid line of sight RF and RF-FSO fixed gain dual-hop transmission systems

    KAUST Repository

    Zedini, Emna

    2014-12-01

    In this work, we carry out a unified performance analysis of a dual-branch transmission system composed of a direct radio-frequency (RF) link and a dual-hop fixed gain relay over the asymmetric links composed of both RF and unified free-space optics (FSO) under the effect of pointing errors. RF links are modeled by the Nakagami-m fading channel and the FSO link by the Gamma-Gamma fading channel subject to both types of detection techniques (i.e. heterodyne detection and intensity modulation with direct detection (IM/DD)). Selection combining (SC) and maximum ratio combining (MRC) diversity schemes are investigated. More specifically, for the SC method, we derive new unified closed-form expressions for the cumulative distribution function (CDF), the probability density function (PDF), the moment generating function (MGF), the moments, the outage probability (OP), the average bit-error rate (BER) of a variety of binary modulations, and the ergodic capacity for end-to-end signal-to-noise ratio (SNR). Additionally, using the MGF-based approach, the evaluation of the OP, the average BER, and the ergodic capacity for the MRC diversity technique can be performed based entirely on the knowledge of the MGF of the output SNR without ever having to compute its statistics (i.e. PDF and CDF). By implementing SC or MRC diversity techniques, we demonstrate a better performance of our system relative to the traditional RF path only. Also, our analysis illustrates MRC as the optimum combing method. All the analytical results are verified via computer-based Monte-Carlo simulations.

  7. Modulating activity in the prefrontal cortex changes decision-making for risky gains and losses: a transcranial direct current stimulation study.

    Science.gov (United States)

    Ye, Hang; Chen, Shu; Huang, Daqiang; Wang, Siqi; Luo, Jun

    2015-06-01

    When making choices under uncertainty, people usually consider both the risks and benefits of each option. Previous studies have found that weighing of risks and benefits during decision-making involves a complex neural network that includes the dorsolateral prefrontal cortex (DLPFC), but the causal effect of this network on risk decision-making has remained unclear. This experiment was based on a risk-measurement table designed to provide a direct measure of risk preference, with a weighted value of the choices (denoted as weighted risk aversion, WRA) as an index of the participant's degree of risk aversion. We studied whether bifrontal transcranial direct current stimulation (tDCS) applied over the right and left prefrontal cortex can change the balance of risky vs. safe responses under both gain frame and loss frame. A total of 60 volunteers performed risk tasks while receiving either anodal over the right with cathodal over the left DLPFC, anodal over the left with cathodal over the right DLPFC, or sham stimulation. The participants tended to choose more risky options in the gain frame and more safe options in the loss frame after the right anodal/left cathodal tDCS. We also found that right anodal/left cathodal tDCS significantly decreased the WRA values compared with those associated with sham stimulation. These findings extend the notion that DLPFC activity is critical for risk decision-making, indicating an asymmetric role of the right DLPFC in the gain frame vs. the loss frame of risk decision-making. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Coordinated Direct and Relay Transmission with Interference Cancelation in Wireless Systems

    DEFF Research Database (Denmark)

    Thai, Chan; Popovski, Petar

    2011-01-01

    Two-way relaying schemes in wireless systems obtain throughput gain by utilizing two features (1) jointly serve two communication flows, thus implementing network coding and (2) use of information that is a priori known to cancel interference and obtain the desired signal. Based on these principles......, we propose other schemes that bring throughput gains in wireless cellular systems, where relayed and direct transmissions are carried out in coordinated way. The results show that the coordinated transmission exhibit throughput improvement similar to the two–way relaying schemes....

  9. ESDIS DOI System, Approach, and Future Direction

    Science.gov (United States)

    Wanchoo, L.; James, N.

    2013-12-01

    that has the data product description. Even though the development and maintenance of DOI landing pages would be the responsibility of the DAACs, ESDIS in consultation with the data providers is currently developing the landing page guidelines that specifies the key data product descriptive elements to be included on each data product's landing page. This poster will describe in detail the unique process and system currently implemented by ESDIS for registering DOIs. In addition, the paper will summarize some of the early implementation shortcomings and how they were addressed, as well as the future directions of the ESDIS DOI system/process.

  10. High Voltage Gain Dual Active Bridge Converter with an Extended Operation Range for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Tomas Manez, Kevin; Yudi, Xiao

    2018-01-01

    Bridge (P2DAB) converter, i.e. low-voltage (LV) side parallel and high-voltage (HV) side series, is proposed to achieve high voltage gain and low current stress over switching devices and transformer windings. Given the unmodified P2DAB power stage, by regulating the phase-shift angle between......Developing bidirectional dc-dc converters has become a critical research topic and gains more and more attention in recent years due to the extensive applications of smart grids with energy storages, hybrid and electrical vehicles and dc microgrids. In this paper, a Partial Parallel Dual Active...... the paralleled active bridges, the power equations and voltage gain are then modified, and therefore the operation range can be extended effectively. The operating principles of the proposed converter and its power characteristics under various operation modes are studied, and the design constraints...

  11. High Voltage Gain Dual Active Bridge Converter with an Extended Operation Range for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Tomas Manez, Kevin; Yudi, Xiao

    2018-01-01

    Developing bidirectional dc-dc converters has become a critical research topic and gains more and more attention in recent years due to the extensive applications of smart grids with energy storages, hybrid and electrical vehicles and dc microgrids. In this paper, a Partial Parallel Dual Active...

  12. Coordinated Transmissions to Direct and Relayed Users in Wireless Cellular Systems

    DEFF Research Database (Denmark)

    Thai, Chan; Popovski, Petar; Kaneko, Megumi

    2011-01-01

    The ideas of wireless network coding at the physical layer promise high throughput gains in wireless systems with relays and multi–way traffic flows. This gain can be ascribed to two principles: (1) joint transmission of multiple communication flows and (2) usage of a priori information to cancel...... the interference. In this paper we use these principles to devise new transmission schemes in wireless cellular systems that feature both users served directly by the base stations (direct users) and users served through relays (relayed users). We present four different schemes for coordinated transmission...... of uplink and downlink traffic in which one direct and one relayed user are served. These schemes are then used as building blocks in multi–user scenarios, where we present several schemes for scheduling pairs of users for coordinated transmissions. The optimal scheme involves exhaustive search of the best...

  13. Noticeable positive Doppler effect on optical bistability in an N-type active Raman gain atomic system

    International Nuclear Information System (INIS)

    Chang Zeng-Guang; Zhang Jing-Tao; Niu Yue-Ping; Gong Shang-Qing

    2012-01-01

    We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion and thus create the bistable behaviour or greatly increase the bistable region, which has been known as the positive Doppler effect on optical bistability. In addition, we find that a positive Doppler effect can change optical bistability from the hybrid dispersion-gain type to a dispersive type

  14. Superluminal propagation in a poly-chromatically driven gain assisted four-level N-type atomic system

    International Nuclear Information System (INIS)

    Bacha, Bakht Amin; Ahmad, Iftikhar; Ullah, Arif; Ali, Hazrat

    2013-01-01

    We investigate the behavior of light propagation in an N-type four-level gain assisted model (Agarwal and Dasgupta 2004 Phys. Rev. A 70 023802) under poly-chromatic pump fields. The system exhibits interesting results of multiple controllable pairs of the gain doublet profile with changes in the intensity of the control field. We observe multiple anomalous dispersive regions for superluminal propagation in the medium. A negative group velocity of −37.50 m s −1 with a negative time delay of −8 ms is observed between each gain doublet in anomalous dispersive regions. This generalized model and its predictions can be tested with existing experimental setups. (paper)

  15. Prediction of the mass gain during high temperature oxidation of aluminized nanostructured nickel using adaptive neuro-fuzzy inference system

    Science.gov (United States)

    Hayati, M.; Rashidi, A. M.; Rezaei, A.

    2012-10-01

    In this paper, the applicability of ANFIS as an accurate model for the prediction of the mass gain during high temperature oxidation using experimental data obtained for aluminized nanostructured (NS) nickel is presented. For developing the model, exposure time and temperature are taken as input and the mass gain as output. A hybrid learning algorithm consists of back-propagation and least-squares estimation is used for training the network. We have compared the proposed ANFIS model with experimental data. The predicted data are found to be in good agreement with the experimental data with mean relative error less than 1.1%. Therefore, we can use ANFIS model to predict the performances of thermal systems in engineering applications, such as modeling the mass gain for NS materials.

  16. [Acupuncture Intervention Reduced Weight Gain Induced by Hypoglycemic Agents through Food Intake-related Targets in Central Nervous System].

    Science.gov (United States)

    Jing, Xin-yue; Ou, Chen; Lu, Sheng-feng; Zhu, Bing-mei

    2015-12-01

    Clinical practice shows that thiazolidinediones (TZDs) induce weight gain in patients with type-II diabetes mellitus during treatment, which restrains its application and generalization clinically. It has been demonstrated that acupuncture therapy is useful in easing obesity in clinical trials. In the present paper, we summarize the underlying mechanism of weight gain induced by TZDs through food intake-related targets in the central nervous system and analyze the possible effects of acupuncture therapy. Acupuncture therapy is expected to reduce weight gain side effect of TZDs through 1) lowering permeability of blood brain barrier to reduce TZDs concentration in the brain, 2) upregulating the expression of hypothalamic leptin and inhibiting hypothalamic neuropiptide Y expression, and 3) down-regulating activities of peroxisome proliferator-activated receptor to reduce energy intake and fat syntheses.

  17. An inverse method for calculation of thermal inertia and heat gain in air conditioning and refrigeration systems

    International Nuclear Information System (INIS)

    Fayazbakhsh, M.A.; Bagheri, F.; Bahrami, M.

    2015-01-01

    Highlights: • An inverse method is proposed to calculate thermal inertia in HVAC-R systems. • Real-time thermal loads are estimated using the proposed intelligent algorithm. • Calculation algorithm is validated with on-site measurements. • Freezer duty cycle data are extracted only based on temperature measurements. - Abstract: A new inverse method is proposed for estimation of thermal inertia and heat gain in air conditioning and refrigeration systems using on-site temperature measurements. The method is applied on a walk-in freezer room of a restaurant in Surrey, British Columbia, Canada during one week of its regular operation. The thermal inertia and instantaneous heat gain are calculated and the results are validated using actual information of the materials inside the freezer room. The proposed method can be implemented in intelligent control systems designed for new and existing HVAC-R systems to improve their overall energy efficiency and reduce their environmental impacts

  18. A current mode feed-forward gain control system for a 0.8 V CMOS hearing aid

    Energy Technology Data Exchange (ETDEWEB)

    Li Fanyang; Yang Haigang; Liu Fei; Yin Tao, E-mail: yanghg@mail.ie.ac.cn [Institute of Electronics, Chinese Academy of Sciences, Beijing 100080 (China)

    2011-06-15

    A current mode feed-forward gain control (CMFGC) technique is presented, which is applied in the front-end system of a hearing aid chip. Compared with conventional automatic gain control (AGC), CMFGC significantly improves the total harmonic distortion (THD) by digital gain control. To attain the digital gain control codes according to the extremely weak output signal from the microphone, a rectifier and a state controller implemented in current mode are proposed. A prototype chip has been designed based on a 0.13 {mu}m standard CMOS process. The measurement results show that the supply voltage can be as low as 0.6 V. And with the 0.8 V supply voltage, the THD is improved and below 0.06% (-64 dB) at the output level of 500 mV{sub p-p}, yet the power consumption is limited to 40 {mu}W. In addition, the input referred noise is only 4 {mu}V{sub rms} and the maximum gain is maintained at 33 dB. (semiconductor integrated circuits)

  19. A current mode feed-forward gain control system for a 0.8 V CMOS hearing aid

    International Nuclear Information System (INIS)

    Li Fanyang; Yang Haigang; Liu Fei; Yin Tao

    2011-01-01

    A current mode feed-forward gain control (CMFGC) technique is presented, which is applied in the front-end system of a hearing aid chip. Compared with conventional automatic gain control (AGC), CMFGC significantly improves the total harmonic distortion (THD) by digital gain control. To attain the digital gain control codes according to the extremely weak output signal from the microphone, a rectifier and a state controller implemented in current mode are proposed. A prototype chip has been designed based on a 0.13 μm standard CMOS process. The measurement results show that the supply voltage can be as low as 0.6 V. And with the 0.8 V supply voltage, the THD is improved and below 0.06% (-64 dB) at the output level of 500 mV p-p , yet the power consumption is limited to 40 μW. In addition, the input referred noise is only 4 μV rms and the maximum gain is maintained at 33 dB. (semiconductor integrated circuits)

  20. Spatially resolved x-ray laser spectra and demonstration of gain in nickel-like systems

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, D.A.; Keane, C.J.; MacGowan, B.J.; Matthews, D.L.; Trebes, J.E.; Eckart, M.J.

    1987-09-25

    A recent series of experiments have provided spatially resolved near field images of several candidate x-ray lasing transition in neon-like, nickel-like, and hydrogen-like ions from laser-produced plasmas. From these time-gated, spatially, and spectrally resolved measurements the source size for the J = 0 - 1 and the J = 2 - 1 transitions in Ne-like selenium have been determined. Source regions as small as 50 ..mu..m have been observed on transitions with gain-length products >9. In addition, we have obtained the first experimental evidence for the amplification of spontaneous emission in the nickel-like ions of europium and ytterbium. Gains of order 1 cm/sup -1/ and gain-length products of up to 3.8 are observed on the J = 0 - 1, 4d-4p transitions in Eu + 35 at 65.26 and 71.00 A. Analogous transitions in Yb = +42 have been identified and some evidence for ASE has been observed. 7 refs., 11 figs.

  1. Spatially resolved X-ray laser spectra and demonstration of gain in nickel-like systems

    International Nuclear Information System (INIS)

    Whelan, D.A.; Keane, C.J.; MacGowan, B.J.; Matthews, D.L.; Trebes, J.E.; Eckart, M.J.

    1987-01-01

    A recent series of experiments have provided spatially resolved near field images of several candidate x-ray lasing transition in neon-like, nickel-like, and hydrogen-like ions from laser-produced plasmas. From these time-gated, spatially, and spectrally resolved measurements the source size for the J=0-1 and the J=2-1 transitions in Ne-like selenium have been determined. Source regions as small as 50 μm have been observed on transitions with gain-length products >9. In addition, the authors have obtained the first experimental evidence for the amplification of spontaneous emission in the nickel-like ions of europium and ytterbium. Gains of order 1 cm/sup -1/ and gain-length products of up to 3.8 are observed on the J=0-1,4d-4p transitions in Eu/sup +35/ at 65.83 and 71.00A. Analogous transitions in Yb/sup +42/ have been identified and some evidence for ASE has been observed

  2. Mechanism of lumen gain with a novel rotational aspiration atherectomy system for peripheral arterial disease: examination by intravascular ultrasound.

    Science.gov (United States)

    Hassan, Ali H M; Ako, Junya; Waseda, Katsuhisa; Honda, Yasuhiro; Zeller, Thomas; Leon, Martin B; Fitzgerald, Peter J

    2010-01-01

    The purpose of this study was to evaluate the mechanism of luminal gain with a novel atheroablation system (Pathway PV) for the treatment of peripheral artery disease using intravascular ultrasound (IVUS). The atherectomy system is a rotational atherectomy device, which employs expandable rotating blades with ports that allow flushing and aspiration of the plaque material or thrombus. In this first-in-man clinical study, IVUS analysis was available in 6 patients with lower limb ischemia treated with this device. The treatment results were assessed using IVUS at pre and post atherectomy. Lumen beyond burr size (LBB) was defined as lumen gain divided by the estimated burr area determined by the burr-size. IVUS analysis was available in six patients (superficial femoral artery n=3, popliteal artery n=2, posterior tibial artery n=1). Atheroablation achieved a significant increase in lumen area (LA) (preintervention 3.9+/-0.4, postatheroablation 8.0+/-1.7 mm(2), Patherectomy device achieved significant luminal gain by debulking in the absence of vessel stretching. The LA was greater than burr-sized lumen expectancy at cross-sections along the treated segments, suggesting a complimentary role of aspiration in luminal gain in atherosclerotic peripheral artery lesions.

  3. Career Directions--Renewable Energy Systems Integrator

    Science.gov (United States)

    Fleeman, Stephen R.

    2012-01-01

    Renewable energy systems are beginning to appear everywhere. Solar modules are creating "blue roofs" that convert the energy from the sun into household electricity. Solar thermal systems on roofs can generate hot water. Wind turbines catch breezes to provide even more electricity. Recommendations for saving energy, specifying systems for…

  4. Research Directions in Real-Time Systems.

    Science.gov (United States)

    1996-09-01

    This report summarizes a survey of published research in real time systems . Material is presented that provides an overview of the topic, focusing on...communications protocols and scheduling techniques. It is noted that real - time systems deserve special attention separate from other areas because of...formal tools for design and analysis of real - time systems . The early work on applications as well as notable theoretical advances are summarized

  5. Water hammers in direct contact heater systems

    International Nuclear Information System (INIS)

    Uffer, R.

    1983-01-01

    This paper discusses the causes and mitigation or prevention of water hammers occurring in direct contact heaters and their attached lines. These water hammers are generally caused by rapid pressure reductions in the heaters or by water lines not flowing full. Proper design and operating measures can prevent or mitigate water hammer occurrence. Water hammers often do not originate at the areas where damage is noted

  6. Power electronic converter systems for direct drive renewable energy applications

    DEFF Research Database (Denmark)

    Chen, Zhe

    2013-01-01

    This chapter presents power electronic conversion systems for wind and marine energy generation applications, in particular, direct drive generator energy conversion systems. Various topologies are presented and system design optimization and reliability are briefly discussed....

  7. Gain in computational efficiency by vectorization in the dynamic simulation of multi-body systems

    Science.gov (United States)

    Amirouche, F. M. L.; Shareef, N. H.

    1991-01-01

    An improved technique for the identification and extraction of the exact quantities associated with the degrees of freedom at the element as well as the flexible body level is presented. It is implemented in the dynamic equations of motions based on the recursive formulation of Kane et al. (1987) and presented in a matrix form, integrating the concepts of strain energy, the finite-element approach, modal analysis, and reduction of equations. This technique eliminates the CPU intensive matrix multiplication operations in the code's hot spots for the dynamic simulation of the interconnected rigid and flexible bodies. A study of a simple robot with flexible links is presented by comparing the execution times on a scalar machine and a vector-processor with and without vector options. Performance figures demonstrating the substantial gains achieved by the technique are plotted.

  8. Nuclear plant data systems - some emerging directions

    International Nuclear Information System (INIS)

    Johnson, R.D.; Humphress, G.B.; McCullough, L.D.; Tashjian, B.M.

    1983-01-01

    Significant changes have occurred in recent years in the nuclear power industry to accentuate the need for data systems to support information flow and decision making. Economic conditions resulting in rapid inflation and larger investments in new and existing plants and the need to plan further ahead are primary factors. Government policies concerning environmental control, as well as minimizing risk to the public through increased nuclear safety regulations on operating plants are additional factors. The impact of computer technology on plant data systems, evolution of corporate and plant infrastructures, future plant data, system designs and benefits, and decision making capabilities and data usage support are discussed. (U.K.)

  9. Medical Robots: Current Systems and Research Directions

    Directory of Open Access Journals (Sweden)

    Ryan A. Beasley

    2012-01-01

    Full Text Available First used medically in 1985, robots now make an impact in laparoscopy, neurosurgery, orthopedic surgery, emergency response, and various other medical disciplines. This paper provides a review of medical robot history and surveys the capabilities of current medical robot systems, primarily focusing on commercially available systems while covering a few prominent research projects. By examining robotic systems across time and disciplines, trends are discernible that imply future capabilities of medical robots, for example, increased usage of intraoperative images, improved robot arm design, and haptic feedback to guide the surgeon.

  10. Robust stabilization of nonlinear systems via stable kernel representations with L2-gain bounded uncertainty

    NARCIS (Netherlands)

    van der Schaft, Arjan

    1995-01-01

    The approach to robust stabilization of linear systems using normalized left coprime factorizations with H∞ bounded uncertainty is generalized to nonlinear systems. A nonlinear perturbation model is derived, based on the concept of a stable kernel representation of nonlinear systems. The robust

  11. Free and Licensed Operating Systems: Direct Comparison

    Directory of Open Access Journals (Sweden)

    Samy Hagman

    2015-06-01

    Full Text Available When developers comparing open with proprietary code, which should be a civilized debate often degenerates into a flame war. This paper presents a report on code quality metrics that have been collected from four major operating systems on an industrial scale is as follows: FreeBSD, Linux, OpenSolaris and Windows Research Kernel (WRK. This article is not a mysterious crime and it can be concluded as the main finding no significant differences in the quality of the code of these systems.

  12. Portable direct methanol fuel cell systems

    Science.gov (United States)

    Narayanan, S. R.; Valdez, T. I.

    2002-01-01

    This article includes discussion of the specific power and power density requirements for various portable system applications, the status of stack technology, progress in the implementation of balance-of-plant designs, and a summary of the characteristics of various DMFC portable power source demonstrations.

  13. Electrical drives for direct drive renewable energy systems

    CERN Document Server

    Mueller, Markus

    2013-01-01

    Wind turbine gearboxes present major reliability issues, leading to great interest in the current development of gearless direct-drive wind energy systems. Offering high reliability, high efficiency and low maintenance, developments in these direct-drive systems point the way to the next generation of wind power, and Electrical drives for direct drive renewable energy systems is an authoritative guide to their design, development and operation. Part one outlines electrical drive technology, beginning with an overview of electrical generators for direct drive systems. Principles of electrical design for permanent magnet generators are discussed, followed by electrical, thermal and structural generator design and systems integration. A review of power electronic converter technology and power electronic converter systems for direct drive renewable energy applications is then conducted. Part two then focuses on wind and marine applications, beginning with a commercial overview of wind turbine drive systems and a...

  14. Gain-enhanced LTCC system-on-package for automotive UMRR applications

    KAUST Repository

    Ghaffar, Farhan A.

    2012-07-28

    A novel Low Temperature Co-fired Ceramic (LTCC) based SoP for automotive radar applications is presented. For the first time a combination of a relatively low dielectric constant LTCC substrate and a high dielectric constant LTCC superstrate has been incorporated to enhance the overall gain of the module. The superstrate can provide additional protection to the integrated circuits (IC) in the harsh automotive environment. A custom cavity in the LTCC substrate can accommodate the IC, which feeds an aperture coupled patch antenna array. The cavity is embedded below the ground plane that acts as a shield for the IC from antenna radiation. It is estimated that with mere 10 dBm of transmitted RF power the miniature SoP module (sized 2.0 cm × 2.0 cm × 0.22 cm) can communicate up to 67 m. The design\\'s compactness, robustness, transmission power and resultant communication range are highly suitable for Universal Medium Range Radar (UMRR) applications. © 2010 IEEE.

  15. Direct Fuel Injector Power Drive System Optimization

    Science.gov (United States)

    2014-04-01

    solenoid coil to create magnetic field in the stator. Then, the stator pulls the pintle to open the injector nozzle . This pintle movement occurs when the...that typically deal with power strategies to the injector solenoid coil. Numerical simulation codes for diesel injection systems were developed by...Laboratory) for providing the JP-8 test fuel. REFERENCES 1. Digesu, P. and Laforgia D., “ Diesel electro- injector : A numerical simulation code”. Journal of

  16. Direct methanol feed fuel cell and system

    Science.gov (United States)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2009-01-01

    Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous. The fuel cell system also comprises a fuel supplying part including a meter which meters an amount of fuel which is used by the fuel cell, and controls the supply of fuel based on said metering.

  17. Defining Strong State Accountability Systems: How Can Better Standards Gain Greater Traction? A First Look

    Science.gov (United States)

    Reed, Eileen; Scull, Janie; Slicker, Gerilyn; Winkler, Amber M.

    2012-01-01

    Rigorous standards and aligned assessments are vital tools for boosting education outcomes but they have little traction without strong accountability systems that attach consequences to performance. In this pilot study, Eileen Reed, Janie Scull, Gerilyn Slicker, and Amber Winkler lay out the essential features of such accountability systems,…

  18. LMI-based gain scheduled controller synthesis for a class of linear parameter varying systems

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Anderson, Brian; Lanzon, Alexander

    2006-01-01

    This paper presents a novel method for constructing controllers for a class of single-input multiple-output (SIMO) linear parameter varying (LPV) systems. This class of systems encompasses many physical systems, in particular systems where individual components vary with time, and is therefore...... of significant practical relevance to control designers. The control design presented in this paper has the properties that the system matrix of the closed loop is multi-affine in the various scalar parameters, and that the resulting controller ensures a certain degree of stability for the closed loop even when...... as a standard linear time-invariant (LTI) design combined with a set of linear matrix inequalities, which can be solved efficiently with software tools. The design procedure is illustrated by a numerical example....

  19. The impact of a Classroom Performance System on learning gains in a biology course for science majors

    Science.gov (United States)

    Marin, Nilo Eric

    This study was conducted to determine if the use of the technology known as Classroom Performance System (CPS), specifically referred to as "Clickers", improves the learning gains of students enrolled in a biology course for science majors. CPS is one of a group of developing technologies adapted for providing feedback in the classroom using a learner-centered approach. It supports and facilitates discussion among students and between them and teachers, and provides for participation by passive students. Advocates, influenced by constructivist theories, claim increased academic achievement. In science teaching, the results have been mixed, but there is some evidence of improvements in conceptual understanding. The study employed a pretest-posttest, non-equivalent groups experimental design. The sample consisted of 226 participants in six sections of a college biology course at a large community college in South Florida with two instructors trained in the use of clickers. Each instructor randomly selected their sections into CPS (treatment) and non-CPS (control) groups. All participants filled out a survey that included demographic data at the beginning of the semester. The treatment group used clicker questions throughout, with discussions as necessary, whereas the control groups answered the same questions as quizzes, similarly engaging in discussion where necessary. The learning gains were assessed on a pre/post-test basis. The average learning gains, defined as the actual gain divided by the possible gain, were slightly better in the treatment group than in the control group, but the difference was statistically non-significant. An Analysis of Covariance (ANCOVA) statistic with pretest scores as the covariate was conducted to test for significant differences between the treatment and control groups on the posttest. A second ANCOVA was used to determine the significance of differences between the treatment and control groups on the posttest scores, after

  20. Monte Carlo analysis of accelerator-driven systems studies on spallation neutron yield and energy gain

    CERN Document Server

    Hashemi-Nezhad, S R; Westmeier, W; Bamblevski, V P; Krivopustov, M I; Kulakov, B A; Sosnin, A N; Wan, J S; Odoj, R

    2001-01-01

    The neutron yield in the interaction of protons with lead and uranium targets has been studied using the LAHET code system. The dependence of the neutron multiplicity on target dimensions and proton energy has been calculated and the dependence of the energy amplification on the proton energy has been investigated in an accelerator-driven system of a given effective multiplication coefficient. Some of the results are compared with experimental findings and with similar calculations by the DCM/CEM code of Dubna and the FLUKA code system used in CERN. (14 refs).

  1. Stochastic resonance in a gain-noise model of a single-mode laser driven by pump noise and quantum noise with cross-correlation between real and imaginary parts under direct signal modulation

    Institute of Scientific and Technical Information of China (English)

    Chen Li-Mei; Cao Li; Wu Da-Jin

    2007-01-01

    Stochastic resonance (SR) is studied in a gain-noise model of a single-mode laser driven by a coloured pump noise and a quantum noise with cross-correlation between real and imaginary parts under a direct signal modulation. By using a linear approximation method, we find that the SR appears during the variation of signal-to-noise ratio (SNR)separately with the pump noise self-correlation time τ, the noise correlation coefficient between the real part and the imaginary part of the quantum noise λq, the attenuation coefficient γ and the deterministic steady-state intensity I0.In addition, it is found that the SR can be characterized not only by the dependence of SNR on the noise variables of τand λq, but also by the dependence of SNR on the laser system variables of γ and I0. Thus our investigation extends the characteristic quantity of SR proposed before.

  2. Mid-IR Lasers: Challenges Imposed by the Population Dynamics of the Gain System

    Science.gov (United States)

    2010-09-01

    MicroSystems (IOMS) Central-Field Approximation: Perturbations 1. a) Non-centrosymmetric splitting (Coulomb interaction) ⇒ total orbital angular momentum b...Accordingly: ⇒ total electron-spin momentum 2. Spin-orbit coupling (“LS” coupling) ⇒ total angular momentum lanthanides: intermediate coupling (LS / jj) 3...MicroSystems (IOMS) Luminescence Decay Curves Rate-equation for decay: Solution ( Bernoulli -Eq.): Linearized solution: T. Jensen, Ph.D. Thesis, Univ. Hamburg

  3. Transportable Vitrification System: Operational experience gained during vitrification of simulated mixed waste

    International Nuclear Information System (INIS)

    Whitehouse, J.C.; Burket, P.R.; Crowley, D.A.; Hansen, E.K.; Jantzen, C.M.; Smith, M.E.; Singer, R.P.; Young, S.R.; Zamecnik, J.R.; Overcamp, T.J.; Pence, I.W. Jr.

    1996-01-01

    The Transportable Vitrification System (TVS) is a large-scale, fully-integrated, transportable, vitrification system for the treatment of low-level nuclear and mixed wastes in the form of sludges, soils, incinerator ash, and similar waste streams. The TVS was built to demonstrate the vitrification of actual mixed waste at U. S. Department of Energy (DOE) sites. Currently, Westinghouse Savannah River Company (WSRC) is working with Lockheed Martin Energy Systems (LMES) to apply field scale vitrification to actual mixed waste at Oak Ridge Reservation's (ORR) K-25 Site. Prior to the application of the TVS to actual mixed waste it was tested on simulated K-25 B and C Pond waste at Clemson University. This paper describes the results of that testing and preparations for the demonstration on actual mixed waste

  4. Gain scheduling for non-linear time-delay systems using approximated model

    NARCIS (Netherlands)

    Pham, H.T.; Lim, J.T

    2012-01-01

    The authors investigate a regulation problem of non-linear systems driven by an exogenous signal and time-delay in the input. In order to compensate for the input delay, they propose a reduction transformation containing the past information of the control input. Then, by utilising the Euler

  5. Deliberation in the Motor System: Reflex Gains Track Evolving Evidence Leading to a Decision

    NARCIS (Netherlands)

    Selen, L.P.J.; Shadlen, M.N.; Wolpert, D.M.

    2012-01-01

    Both decision making and sensorimotor control require real-time processing of noisy information streams. Historically these processes were thought to operate sequentially: cognitive processing leads to a decision, and the outcome is passed to the motor system to be converted into action. Recently,

  6. Efficiency gains of photovoltaic system using latent heat thermal energy storage

    NARCIS (Netherlands)

    Tan, Lippong; Date, Abhijit; Fernandes, Gabriel; Singh, Baljit; Ganguly, Sayantan

    This paper presents experimental assessments of the thermal and electrical performance of photovoltaic (PV) system by comparing the latent heat-cooled PV panel with the naturally-cooled equivalent. It is commonly known that the energy conversion efficiency of the PV cells declines with the increment

  7. BER analysis of multi-hop heterodyne FSO systems with fixed gain relays over general Malaga turbulence channels

    KAUST Repository

    Alheadary, Wael Ghazy

    2017-07-20

    This work investigates the end-to-end performance of a free space optical amplify-and-forward (AF) fixed-gain relaying system using heterodyne detection over misaligned general Malaga turbulence channels. More specifically, we present exact closed-form expressions for average bit-error rate achievable spectral efficiency non-adaptive/adaptive modulation schemes by employing generalized power series identity of Meijer\\'s G-function. Moreover, asymptotic closed-form expressions are derived to validate our results at high signal-to-noise ratio. In addition, the analytical results have been presented with compare to range of numerical values.

  8. BER analysis of multi-hop heterodyne FSO systems with fixed gain relays over general Malaga turbulence channels

    KAUST Repository

    Alheadary, Wael Ghazy; Park, Kihong; Alouini, Mohamed-Slim

    2017-01-01

    This work investigates the end-to-end performance of a free space optical amplify-and-forward (AF) fixed-gain relaying system using heterodyne detection over misaligned general Malaga turbulence channels. More specifically, we present exact closed-form expressions for average bit-error rate achievable spectral efficiency non-adaptive/adaptive modulation schemes by employing generalized power series identity of Meijer's G-function. Moreover, asymptotic closed-form expressions are derived to validate our results at high signal-to-noise ratio. In addition, the analytical results have been presented with compare to range of numerical values.

  9. Gain and offset calibration reduces variation in exposure-dependent SNR among systems with identical digital flat-panel detectors.

    Science.gov (United States)

    Willis, Charles E; Vinogradskiy, Yevgeniy Y; Lofton, Brad K; White, R Allen

    2011-07-01

    The conditions under which vendor performance criteria for digital radiography systems are obtained do not adequately simulate the conditions of actual clinical imaging with respect to radiographic technique factors, scatter production, and scatter control. Therefore, the relationship between performance under ideal conditions and performance in clinical practice remains unclear. Using data from a large complement of systems in clinical use, the authors sought to develop a method to establish expected performance criteria for digital flat-panel radiography systems with respect to signal-to-noise ratio (SNR) versus detector exposure under clinical conditions for thoracic imaging. The authors made radiographic exposures of a patient-equivalent chest phantom at 125 kVp and 180 cm source-to-image distance. The mAs value was modified to produce exposures above and below the mAs delivered by automatic exposure control. Exposures measured free-in-air were corrected to the imaging plane by the inverse square law, by the attenuation factor of the phantom, and by the Bucky factor of the grid for the phantom, geometry, and kilovolt peak. SNR was evaluated as the ratio of the mean to the standard deviation (SD) of a region of interest automatically selected in the center of each unprocessed image. Data were acquired from 18 systems, 14 of which were tested both before and after gain and offset calibration. SNR as a function of detector exposure was interpolated using a double logarithmic function to stratify the data into groups of 0.2, 0.5, 1.0, 2.0, and 5.0 mR exposure (1.8, 4.5, 9.0, 18, and 45 microGy air KERMA) to the detector. The mean SNR at each exposure interval after calibration exhibited linear dependence on the mean SNR before calibration (r2=0.9999). The dependence was greater than unity (m = 1.101 +/- 0.006), and the difference from unity was statistically significant (p grid replacement. The nonconformant behavior of the other system was corrected by replacing

  10. Realization of a gain with electromagnetically induced transparency system using non-degenerate Zeeman sublevels in 87 Rb

    Science.gov (United States)

    Zhou, Minchuan; Zhou, Zifan; Shahriar, Selim M.

    2017-11-01

    Previously, we had proposed an optically-pumped five-level Gain EIT (GEIT) system, which has a transparency dip superimposed on a gain profile and exhibits a negative dispersion suitable for the white-light-cavity signal-recycling (WLC-SR) scheme of the interferometric gravitational wave detector (Zhou et al., 2015). Using this system as the negative dispersion medium (NDM) in the WLC-SR, we get an enhancement in the quantum noise (QN) limited sensitivity-bandwidth product by a factor of ∼ 18. Here, we show how to realize this GEIT system in a realistic platform, using non-degenerate Zeeman sublevels in cold Rb atoms, employing anomalous dispersion at 795 nm. Using the Caves model for a phase insensitive linear amplifier, we show that an enhancement of the sensitivity-bandwidth product by a factor of ∼ 17 is possible for potentially realizable experimental parameters. While the current LIGO apparatus uses light at 1064 nm, a future embodiment thereof may operate at a wavelength that is consistent with the wavelength considered here.

  11. Challenges in Gaining Large Scale Carbon Reductions through Wireless Home Automation Systems

    DEFF Research Database (Denmark)

    Larsen, Peter Gorm; Rovsing, Poul Ejnar; Toftegaard, Thomas Skjødeberg

    2010-01-01

    Buildings account for more than a 35 % of the energy consumption in Europe. Therefore a step towards more sustainable lifestile is to use home automation to optimize the energy consumption “automatically”. This paper reports about the usage and some of the remaining challenges of especially...... wireless but also powerline communication in a home automation setting. For many years, home automation has been visible to many, but accessible to only a few, because of inadequate integration of systems. A vast number of both standard and proprietary communication protocols are used, and systems...... are often difficult to install and configure so professional assistance is needed. In this paper we report about our experience in constructing an open universal home automation framework enabling interoperability of multiple communication protocols. The framework can easily be expanded in order to support...

  12. Experience gained in using a computer-aided teaching system in Azov maritime institute

    Directory of Open Access Journals (Sweden)

    Олександр Миколайович Зиновченко

    2017-06-01

    Full Text Available Brief analysis of the known teaching methods through the use of computer has been given. Computer-aided teaching system includes an interactive lecture, laboratory works, an application for online testing and evaluation of the new knowledge assimilation and the software used by the teacher. The virtual lecture presents information as sound tracked dynamic pictures accompanied by permanent practical work that fixes the acquired knowledge in the student’s mind. Each teaching step in the virtual lecture is followed with practical work evaluated by the computer. Virtual labs make it possible to consolidate the new knowledge by practice. They provide for the individual activity of the student, monitor his progress and automatically evaluate his knowledge. These applications are installed in the student's computer. The computer applications of the teacher include a generator of the tests for testing and evaluation of the new knowledge, a typical problems base, personal information files generator for each student and a computer application forming the final mark of the student. The results of the testing of this teaching system show that it is efficient, making it possible to organize a flexible schedule of the educational process,cutting down the working hours of the teacher

  13. Direct and Indirect Effects of PM on the Cardiovascular System

    Science.gov (United States)

    Nelin, Timothy D.; Joseph, Allan M.; Gorr, Matthew W.; Wold, Loren E.

    2011-01-01

    Human exposure to particulate matter (PM) elicits a variety of responses on the cardiovascular system through both direct and indirect pathways. Indirect effects of PM on the cardiovascular system are mediated through the autonomic nervous system, which controls heart rate variability, and inflammatory responses, which augment acute cardiovascular events and atherosclerosis. Recent research demonstrates that PM also affects the cardiovascular system directly by entry into the systemic circulation. This process causes myocardial dysfunction through mechanisms of reactive oxygen species production, calcium ion interference, and vascular dysfunction. In this review, we will present key evidence in both the direct and indirect pathways, suggest clinical applications of the current literature, and recommend directions for future research. PMID:22119171

  14. High Temperature 300°C Directional Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Kamalesh [Baker Hughes Oilfield Operations, Houston, TX (United States); Aaron, Dick [Baker Hughes Oilfield Operations, Houston, TX (United States); Macpherson, John [Baker Hughes Oilfield Operations, Houston, TX (United States)

    2015-07-31

    Many countries around the world, including the USA, have untapped geothermal energy potential. Enhanced Geothermal Systems (EGS) technology is needed to economically utilize this resource. Temperatures in some EGS reservoirs can exceed 300°C. To effectively utilize EGS resources, an array of injector and production wells must be accurately placed in the formation fracture network. This requires a high temperature directional drilling system. Most commercial services for directional drilling systems are rated for 175°C while geothermal wells require operation at much higher temperatures. Two U.S. Department of Energy (DOE) Geothermal Technologies Program (GTP) projects have been initiated to develop a 300°C capable directional drilling system, the first developing a drill bit, directional motor, and drilling fluid, and the second adding navigation and telemetry systems. This report is for the first project, “High Temperature 300°C Directional Drilling System, including drill bit, directional motor and drilling fluid, for enhanced geothermal systems,” award number DE-EE0002782. The drilling system consists of a drill bit, a directional motor, and drilling fluid. The DOE deliverables are three prototype drilling systems. We have developed three drilling motors; we have developed four roller-cone and five Kymera® bits; and finally, we have developed a 300°C stable drilling fluid, along with a lubricant additive for the metal-to-metal motor. Metal-to-metal directional motors require coatings to the rotor and stator for wear and corrosion resistance, and this coating research has been a significant part of the project. The drill bits performed well in the drill bit simulator test, and the complete drilling system has been tested drilling granite at Baker Hughes’ Experimental Test Facility in Oklahoma. The metal-to-metal motor was additionally subjected to a flow loop test in Baker Hughes’ Celle Technology Center in Germany, where it ran for more than 100

  15. Direct evidence for T violation in the neutral kaon system

    CERN Document Server

    Adler, R; Angelopoulos, Angelos; Aspostolakis, A; Aslanides, Elie; Backenstoss, Gerhard; Bee, C P; Behnke, O; Benelli, A; Bertin, V; Blanc, F; Bloch, P; Bula, C; Carlson, P J; Carroll, M; Carvalho, J; Cawley, E; Charalambous, S; Chardalas, M; Chardin, G; Chertok, M B; Cody, A; Danielsson, M; Dedoussis, S; Dejardin, M; Derré, J; Duclos, J; Ealet, A; Eckart, B; Eleftheriadis, C; Evangelou, I; Faravel, L; Fassnacht, P; Faure, J L; Felder, C; Ferreira-Marques, R; Fetscher, W; Fidecaro, Maria; Filipcic, A; Francis, D; Fry, J; Gabathuler, Erwin; Gamet, R; Garreta, D; Gerber, H J; Go, A; Guyot, C; Haselden, A; Hayman, P J; Henry-Coüannier, F; Hollander, R W; Hubert, E; Jon-And, K; Kettle, P R; Kochowski, Claude; Kokkas, P; Kreuger, R; Le Gac, R; Leimgruber, F; Liolios, A; Machado, E; Mandic, I; Manthos, N; Marel, Gérard; Mikuz, M; Miller, J; Montanet, François; Nakada, Tatsuya; Onofre, A; Pagels, B; Papadopoulos, I M; Pavlopoulos, P; Pinto da Cunha, J; Policarpo, Armando; Polivka, G; Rickenbach, R; Roberts, B L; Rozaki, E; Ruf, T; Sakelliou, L; Sanders, P; Santoni, C; Sarigiannis, K; Schäfer, M; Schaller, L A; Schopper, A; Schune, P; Soares, A; Tauscher, Ludwig; Thibault, C; Touchard, F; Touramanis, C; Triantis, F A; Van Beveren, E; van Eijk, C W E; Varner, G S; Vlachos, S; Weber, P; Wigger, O; Wolter, M; Yéche, C; Zavrtanik, D; Zimmerman, D

    1995-01-01

    We present the first direct observation of T violation in the neutral kaon system, showing a positive signal with a significance of more than two standard deviations. The result does not rely on the validity of the CPT theorem.

  16. Direct evidence for T violation in the neutral kaon system

    International Nuclear Information System (INIS)

    Dejardin, M.; Angelopoulos, A.; Apostolakis, A.; Aslanides, E.; Bertin, V.; Behnke, O.; Benelli, A.

    1995-01-01

    The first direct observation of T violation in the neutral kaon system, is presented showing a positive signal with a significance of more than two standard deviations. The results does not rely on the validity of the CPT theorem. (author)

  17. Performance of a Combined System Using an X-Ray FEL Oscillator and a High-Gain FEL Amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, L.; Lindberg, R.; Kim, K. -J.

    2017-06-01

    The LCLS-II at SLAC will feature a 4 GeV CW superconducting (SC) RF linac [1] that can potentially drive a 5th harmonic X-Ray FEL Oscillator (XFELO) to produce fully coherent, 1 MW photon pulses with a 5 meV bandwidth at 14.4 keV [2]. The XFELO output can serve as the input seed signal for a high-gain FEL amplifier employing fs electron beams from the normal conducting SLAC linac, thereby generating coherent, fs x-ray pulses with TW peak powers using a tapered undulator after saturation [3]. Coherent, intense output at several tens of keV will also be feasible if one considers a harmonic generation scheme. Thus, one can potentially reach the 42 keV photon energy required for the MaRIE project [4] by beginning with an XFELO operating at the 3rd harmonic to produce 14.0 keV photons using a 12 GeV SCRF linac, and then subsequently using the high-gain harmonic generation scheme to generate and amplify the 3th harmonic at 42 keV [5]. We report extensive GINGER simulations that determine an optimized parameter set for the combined system.

  18. Modifying Directionality through Auditory System Scaling in a Robotic Lizard

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    2010-01-01

    The peripheral auditory system of a lizard is strongly directional. This directionality is created by acoustical coupling of the two eardrums and is strongly dependent on characteristics of the middle ear, such as interaural distance, resonance frequency of the middle ear cavity and of the tympanum....... Therefore, directionality should be strongly influenced by their scaling. In the present study, we have exploited an FPGA–based mobile robot based on a model of the lizard ear to investigate the influence of scaling on the directional response, in terms of the robot’s performance in a phonotaxis task...

  19. Office of Storage and Transportation Systems quality assurance directive

    International Nuclear Information System (INIS)

    1986-10-01

    This Directive provides policy guidance, defines organizational authorities and responsibilities for quality assurance (QA) and establishes minimum acceptable requirements for assuring the quality of all programs under the overall direction of the OSTS. This directive provides guidance for preparation of subordinate QA documents (e.g., QA plans, procedures) for the major Office of Storage and Transportation Systems programs that support DOE licensing and/or certification objectives. In turn, those highly specific QA documents will amplify the general guidance presented in this Directive

  20. Performance of a directly-coupled PV water pumping system

    International Nuclear Information System (INIS)

    Mokeddem, Abdelmalek; Midoun, Abdelhamid; Kadri, D.; Hiadsi, Said; Raja, Iftikhar A.

    2011-01-01

    Highlights: → Directly coupled PV water pumping system installed and performance studied. → Configured for two static heads, operate without electronic control and auxiliary power. → The system attains steady state soon after any abrupt change. → Cost effective and useful for low head communicating wells system. - Abstract: This paper describes the experimental study carried out to investigate the performance of a simple, directly coupled dc photovoltaic (PV) powered water pumping system. The system comprises of a 1.5 kWp PV array, dc motor and a centrifugal pump. The experiment was conducted over a period of 4 months and the system performance was monitored under different climatic conditions and varying solar irradiance with two static head configurations. Although the motor-pump efficiency did not exceed 30%, which is typical for directly-coupled photovoltaic pumping systems, such a system is clearly suitable for low head irrigation in the remote areas, not connected to the national grid and where access to water comes as first priority issue than access to technology. The system operates without battery and complex electronic control, therefore not only the initial cost is low but also maintenance, repairing and replacement cost can be saved. The study showed that directly coupled system attains steady state soon after any abrupt change.

  1. An AC modulated near infrared gain calibration system for a “Violin-Mode” transimpedance amplifier, intended for advanced LIGO suspensions

    International Nuclear Information System (INIS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a “tall-thin” rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse “Violin-Mode” vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor’s DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor’s more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz–300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m"−"1 was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC

  2. An AC modulated near infrared gain calibration system for a “Violin-Mode” transimpedance amplifier, intended for advanced LIGO suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance) Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2016-07-15

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a “tall-thin” rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse “Violin-Mode” vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor’s DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor’s more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz–300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m{sup −1} was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC

  3. Design and simulation of the direct drive servo system

    Science.gov (United States)

    Ren, Changzhi; Liu, Zhao; Song, Libin; Yi, Qiang; Chen, Ken; Zhang, Zhenchao

    2010-07-01

    As direct drive technology is finding their way into telescope drive designs for its many advantages, it would push to more reliable and cheaper solutions for future telescope complex motion system. However, the telescope drive system based on the direct drive technology is one high integrated electromechanical system, which one complex electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. The telescope is one ultra-exact, ultra-speed, high precision and huge inertial instrument, which the direct torque motor adopted by the telescope drive system is different from traditional motor. This paper explores the design process and some simulation results are discussed.

  4. Adaptive Jamming Suppression in Coherent FFH System Using Weighted Equal Gain Combining Receiver over Fading Channels with Imperfect CSI

    Directory of Open Access Journals (Sweden)

    Yishan He

    2015-01-01

    Full Text Available Fast frequency hopping (FFH is commonly used as an antijamming communication method. In this paper, we propose efficient adaptive jamming suppression schemes for binary phase shift keying (BPSK based coherent FFH system, namely, weighted equal gain combining (W-EGC with the optimum and suboptimum weighting coefficient. We analyze the bit error ratio (BER of EGC and W-EGC receivers with partial band noise jamming (PBNJ, frequency selective Rayleigh fading, and channel estimation errors. Particularly, closed-form BER expressions are presented with diversity order two. Our analysis is verified by simulations. It is shown that W-EGC receivers significantly outperform EGC. As compared to the maximum likelihood (ML receiver in conventional noncoherent frequency shift keying (FSK based FFH, coherent FFH/BPSK W-EGC receivers also show significant advantages in terms of BER. Moreover, W-EGC receivers greatly reduce the hostile jammers’ jamming efficiency.

  5. Comparison between iterative wavefront control algorithm and direct gradient wavefront control algorithm for adaptive optics system

    International Nuclear Information System (INIS)

    Cheng Sheng-Yi; Liu Wen-Jin; Chen Shan-Qiu; Dong Li-Zhi; Yang Ping; Xu Bing

    2015-01-01

    Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltages directly from wavefront slopes through pre-measuring the relational matrix between deformable mirror actuators and Hartmann wavefront sensor with perfect real-time characteristic and stability. However, with increasing the number of sub-apertures in wavefront sensor and deformable mirror actuators of adaptive optics systems, the matrix operation in direct gradient algorithm takes too much time, which becomes a major factor influencing control effect of adaptive optics systems. In this paper we apply an iterative wavefront control algorithm to high-resolution adaptive optics systems, in which the voltages of each actuator are obtained through iteration arithmetic, which gains great advantage in calculation and storage. For AO system with thousands of actuators, the computational complexity estimate is about O(n 2 ) ∼ O(n 3 ) in direct gradient wavefront control algorithm, while the computational complexity estimate in iterative wavefront control algorithm is about O(n) ∼ (O(n) 3/2 ), in which n is the number of actuators of AO system. And the more the numbers of sub-apertures and deformable mirror actuators, the more significant advantage the iterative wavefront control algorithm exhibits. (paper)

  6. Critical coupling and coherent perfect absorption for ranges of energies due to a complex gain and loss symmetric system

    International Nuclear Information System (INIS)

    Hasan, Mohammad; Ghatak, Ananya; Mandal, Bhabani Prasad

    2014-01-01

    We consider a non-Hermitian medium with a gain and loss symmetric, exponentially damped potential distribution to demonstrate different scattering features analytically. The condition for critical coupling (CC) for unidirectional wave and coherent perfect absorption (CPA) for bidirectional waves are obtained analytically for this system. The energy points at which total absorption occurs are shown to be the spectral singular points for the time reversed system. The possible energies at which CC occurs for left and right incidence are different. We further obtain periodic intervals with increasing periodicity of energy for CC and CPA to occur in this system. -- Highlights: •Energy ranges for CC and CPA are obtained explicitly for complex WS potential. •Analytical conditions for CC and CPA for PT symmetric WS potential are obtained. •Conditions for left and right CC are shown to be different. •Conditions for CC and CPA are shown to be that of SS for the time reversed system. •Our model shows the great flexibility of frequencies for CC and CPA

  7. Direct electromechanical driving systems: diversity, constraints and solutions; Les entrainements electromecaniques directs: diversite, contraintes et solutions

    Energy Technology Data Exchange (ETDEWEB)

    Multon, B. [Ecole Normale Superieure, 94 - Cachan (France); Bonal, J. [Promethee Groupe Schneider Electric S.A., 92 - Boulogne-Billancourt (France)

    1999-11-01

    Direct electromechanical drives are the simplest possible transmission systems requiring no additional mechanical components such as gearboxes or rotary to linear converters. This simplicity leads a number of advantages including greater reliability, less maintenance, improved dynamic characteristics and reduced weight and volume. However, the performance specification of direct drives is usually high, with a correspondingly high cost, and often this cannot be justified in complete systems where the other components limit the overall performance. This factor alone has been sufficient to restrict the market penetration of direct drives. The majority of applications are in linear actuators, and in motors operating at very high or very low speeds. New developments are constantly being introduced, especially in relation to structures.

  8. Over 10 dB Net Coding Gain Based on 20% Overhead Hard Decision Forward Error Correction in 100G Optical Communication Systems

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Zibar, Darko

    2011-01-01

    We propose a product code with shortened BCH component codes for 100G optical communication systems. Simulation result shows that 10 dB net coding gain is promising at post- FEC BER of 1E-15.......We propose a product code with shortened BCH component codes for 100G optical communication systems. Simulation result shows that 10 dB net coding gain is promising at post- FEC BER of 1E-15....

  9. DIAGNOSTICS OF GASOLINE FUEL SYSTEMS WITH DIRECT INJECTION

    Directory of Open Access Journals (Sweden)

    M. Bulgakov

    2017-11-01

    Full Text Available A method of diagnosing fuel systems with direct injection by means of producing a pressure oscillation in a hydraulic accumulator is presented. Having obtained a signal from pressure sensor it is possible to register a pressure drop at the moment of injection. If the system has a malfunction, then the pressure drop will be higher.

  10. Gaining Access.

    Science.gov (United States)

    Wand, Sean; Thermos, Adam C.

    1998-01-01

    Explains the issues to consider before a college decides to purchase a card-access system. The benefits of automation, questions involving implementation, the criteria for technology selection, what typical card technology involves, privacy concerns, and the placement of card readers are discussed. (GR)

  11. Net Gain

    International Development Research Centre (IDRC) Digital Library (Canada)

    Describing the effect of tax incentives for import, production, and sale of nets and insecticides; and ..... So far, China is the only country where a system for the routine treatment of ...... 1993), and the trials in Ecuador and Peru (Kroeger et al.

  12. Systems modeling for a laser-driven IFE power plant using direct conversion

    International Nuclear Information System (INIS)

    Meier, W R

    2008-01-01

    A variety of systems analyses have been conducted for laser driver IFE power plants being developed as part of the High Average Power Laser (HAPL) program. A key factor determining the economics attractiveness of the power plant is the net power conversion efficiency which increases with increasing laser efficiency, target gain and fusion-to-electric power conversion efficiency. A possible approach to increasing the power conversion efficiency is direct conversion of ionized target emissions to electricity. This study examines the potential benefits of increased efficiency when the expanding plasma is inductively coupled to an external circuit allowing some of the ion energy to be directly converted to electricity. For base case direct-drive targets with approximately 24% of the target yield in ions, the benefits are modest, especially for chamber designs that operate at high temperature and thus already have relatively high thermal conversion efficiencies. The reduction in the projected cost of electricity is ∼5-10%

  13. Performance comparison of direct and indirect lighting systems

    International Nuclear Information System (INIS)

    Rubinstein, F.; Morse, O.; Clark, T.

    1993-01-01

    The performance of a retrofitted indirect lighting system was compared to the performance of a typical de-lamped direct lighting system in a partitioned office space. Power, illuminance and luminance measurements were made for the de-lamped direct lighting system and after installation of the indirect lighting system with various lamp and ballast combinations. Using the same lamps and ballasts, average workplace illuminance was slightly higher with indirect lighting than with direct lighting. With indirect lighting, workplace lumen efficacy was 4.5% lower due to the higher power draw of the lamps in the more open and cooler indirect fixtures. Indirect lighting with 36 watt T-8 lamps and electronic ballasts achieved an initial average workplace illuminance of 45 foot-candles in the partitioned office space at only 1.1 w/ft 2

  14. Delphi's new direct acting common rail injection system; Das neue Direct Acting Common Rail System von Delphi

    Energy Technology Data Exchange (ETDEWEB)

    Schoeppe, Detlev; Zuelch, Stefan; Geurts, Derk; Gris, Christian; Jorach, Rainer W. [Delphi Diesel Systems, Europe (United Kingdom)

    2009-07-01

    With the serial start of the Direct Acting Common Rail injection system with 2.000 bar Delphi Diesel Systems could supplement its product portfolio with a valuable component. In Delphi's directly propelled Common Rail injector, the Injection needle directly is set in operation with the help of a piezo-ceramic actuator instead of only controlling this with a conventional servo-hydraulic circuit indirectly. This enables a fast opening and closing of the nozzle needle possible independently from the rail pressure. The process of injection is controllable accurately at any time with the again developed two-stage needle movement amplifier. The additionally in the injector integrated fuel storage works as a 'Rail in the Injector' and improves the quality particularly during multiple injection. The injector completely works leakage-free and thereby helps to reach the future CO{sub 2} targets. The use of piezo-actuators as driving force behind the directly working injector leads to a set of requirements to the electronics. A control electronics was developed in order to head optimally the Direct Acting Injector. The sum of all advantages of the Direct Acting of CR systems enables lowest emissions with simultaneously small fuel consumption while new dimensions are reached with power density and engine torque. The authors of the contribution under consideration report on the construction, on the work principle of the Direct Acting CR system and on its performance characteristics as a basis for the premium diesel engine.

  15. Intrinsic gain modulation and adaptive neural coding.

    Directory of Open Access Journals (Sweden)

    Sungho Hong

    2008-07-01

    Full Text Available In many cases, the computation of a neural system can be reduced to a receptive field, or a set of linear filters, and a thresholding function, or gain curve, which determines the firing probability; this is known as a linear/nonlinear model. In some forms of sensory adaptation, these linear filters and gain curve adjust very rapidly to changes in the variance of a randomly varying driving input. An apparently similar but previously unrelated issue is the observation of gain control by background noise in cortical neurons: the slope of the firing rate versus current (f-I curve changes with the variance of background random input. Here, we show a direct correspondence between these two observations by relating variance-dependent changes in the gain of f-I curves to characteristics of the changing empirical linear/nonlinear model obtained by sampling. In the case that the underlying system is fixed, we derive relationships relating the change of the gain with respect to both mean and variance with the receptive fields derived from reverse correlation on a white noise stimulus. Using two conductance-based model neurons that display distinct gain modulation properties through a simple change in parameters, we show that coding properties of both these models quantitatively satisfy the predicted relationships. Our results describe how both variance-dependent gain modulation and adaptive neural computation result from intrinsic nonlinearity.

  16. Comparison of dual-time-constant and fast-acting automatic gain control (AGC) systems in cochlear implants.

    Science.gov (United States)

    Boyle, Patrick J; Büchner, Andreas; Stone, Michael A; Lenarz, Thomas; Moore, Brian C J

    2009-04-01

    Cochlear implants usually employ an automatic gain control (AGC) system as a first stage of processing. AGC1 was a fast-acting (syllabic) compressor. AGC2 was a dual-time-constant system; it usually performed as a slow-acting compressor, but incorporated an additional fast-acting system to provide protection from sudden increases in sound level. Six experienced cochlear-implant users were tested in a counterbalanced order, receiving one-month of experience with a given AGC type before switching to the other type. Performance was evaluated shortly after provision of a given AGC type and after one-month of experience with that AGC type. Questionnaires, mainly relating to listening in quiet situations, did not reveal significant differences between the two AGC types. However, fixed-level and roving-level tests of sentence identification in noise both revealed significantly better performance for AGC2. It is suggested that the poorer performance for AGC1 occurred because AGC1 introduced cross-modulation between the target speech and background noise, which made perceptual separation of the target and background more difficult.

  17. Direct hydrogen fuel cell systems for hybrid vehicles

    Science.gov (United States)

    Ahluwalia, Rajesh K.; Wang, X.

    Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system.

  18. Adjustable Parameter-Based Distributed Fault Estimation Observer Design for Multiagent Systems With Directed Graphs.

    Science.gov (United States)

    Zhang, Ke; Jiang, Bin; Shi, Peng

    2017-02-01

    In this paper, a novel adjustable parameter (AP)-based distributed fault estimation observer (DFEO) is proposed for multiagent systems (MASs) with the directed communication topology. First, a relative output estimation error is defined based on the communication topology of MASs. Then a DFEO with AP is constructed with the purpose of improving the accuracy of fault estimation. Based on H ∞ and H 2 with pole placement, multiconstrained design is given to calculate the gain of DFEO. Finally, simulation results are presented to illustrate the feasibility and effectiveness of the proposed DFEO design with AP.

  19. Chaotification of Quasi-zero Stiffness System Via Direct Time-delay Feedback

    Directory of Open Access Journals (Sweden)

    Shuyong Liu

    2013-03-01

    Full Text Available This paper presents a chaotification method based on direct time-delay feedback control for a quasi-zero-stiffness isolation system. An analytical function of time-delay feedback control is derived based on differential-geometry control theory. Furthermore, the feasibility and effectiveness of this method was verified by numerical simulations. Numerical simulations show that this method holds the favorable aspects including the advantage of using tiny control gain, the capability of chaotifying across a large range of parametric domain and the high feasibility of the control implement.

  20. A model-based gain scheduling approach for controlling the common-rail system for GDI engines

    Science.gov (United States)

    di Gaeta, Alessandro; Montanaro, Umberto; Fiengo, Giovanni; Palladino, Angelo; Giglio, Veniero

    2012-04-01

    The progressive reduction in vehicle emission requirements have forced the automotive industry to invest in research for developing alternative and more efficient control strategies. All control features and resources are permanently active in an electronic control unit (ECU), ensuring the best performance with respect to emissions, fuel economy, driveability and diagnostics, independently from engine working point. In this article, a considerable step forward has been achieved by the common-rail technology which has made possible to vary the injection pressure over the entire engine speed range. As a consequence, the injection of a fixed amount of fuel is more precise and multiple injections in a combustion cycle can be made. In this article, a novel gain scheduling pressure controller for gasoline direct injection (GDI) engine is designed to stabilise the mean fuel pressure into the rail and to track demanded pressure trajectories. By exploiting a simple control-oriented model describing the mean pressure dynamics in the rail, the control structure turns to be simple enough to be effectively implemented in commercial ECUs. Experimental results in a wide range of operating points confirm the effectiveness of the proposed control method to tame efficiently the mean value pressure dynamics of the plant showing a good accuracy and robustness with respect to unavoidable parameters uncertainties, unmodelled dynamics, and hidden coupling terms.

  1. Direct Problems and Inverse Problems in Biometric Systems

    OpenAIRE

    Mihailescu Marius Iulian

    2013-01-01

    The article purpose is to describe the two sides of biometrics technologies, direct problems and inverse problems. The advance that we face today in field of Information Technology makes Information Security an inseparable part. The authentication has a huge role when we deal about security. The problems that can appear in implementing and developing biometrics systems is raising many problems, and one of the goal of this article is to focus on direct and inverse problems which is a new and c...

  2. Bi-directional power control system for voltage converter

    Science.gov (United States)

    Garrigan, Neil Richard; King, Robert Dean; Schwartz, James Edward

    1999-01-01

    A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.

  3. On the performance of hybrid RF and RF/FSO fixed gain dual-hop transmission systems

    KAUST Repository

    Ansari, Imran Shafique

    2013-04-01

    In this work, we present the performance analysis of a dual-branch transmission system composed of a direct radio frequency (RF) link and a dual-hop relay composed of asymmetric RF and free-space optical (FSO) links and compare it without having a direct RF path to see the effects of diversity on our system. The FSO link accounts for pointing errors and both types of detection techniques (i.e. indirect modulation/direct detection (IM/DD) as well as heterodyne detection). The performance is evaluated under the assumption of selection combining diversity scheme. RF links are modeled by Rayleigh fading distribution whereas the FSO link is modeled by a unified Gamma-Gamma fading distribution. Specifically, we derive new exact closed-form expressions for the cumulative distribution function, probability density function, moment generating function, and moments of the end-to-end signal-to-noise ratio of these systems in terms of the Meijer\\'s G function. We then capitalize on these results to offer new exact closed-form expressions for the outage probability, higher-order amount of fading, average error rate for binary and M-ary modulation schemes, and ergodic capacity, all in terms of Meijer\\'s G functions. All our new analytical results are also verified via computer-based Monte-Carlo simulations. © 2013 IEEE.

  4. Photoelectrochemical based direct conversion systems for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Kocha, S.; Peterson, M.; Arent, D. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-10-01

    Photon driven, direct conversion systems consist of a light absorber and a water splitting catalyst as a monolithic system; water is split directly upon illumination. This one-step process eliminates the need to generate electricity externally and subsequently feed it to an electrolyzer. These configurations require only the piping necessary for transport of hydrogen to an external storage system or gas pipeline. This work is focused on multiphoton photoelectrochemical devices for production of hydrogen directly using sunlight and water. Two types of multijunction cells, one consisting of a-Si triple junctions and the other GaInP{sub 2}/GaAs homojunctions, were studied for the photoelectrochemical decomposition of water into hydrogen and oxygen from an aqueous electrolyte solution. To catalyze the water decomposition process, the illuminated surface of the device was modified either by addition of platinum colloids or by coating with ruthenium dioxide. These colloids have been characterized by gel electrophoresis.

  5. Using directed information for influence discovery in interconnected dynamical systems

    Science.gov (United States)

    Rao, Arvind; Hero, Alfred O.; States, David J.; Engel, James Douglas

    2008-08-01

    Structure discovery in non-linear dynamical systems is an important and challenging problem that arises in various applications such as computational neuroscience, econometrics, and biological network discovery. Each of these systems have multiple interacting variables and the key problem is the inference of the underlying structure of the systems (which variables are connected to which others) based on the output observations (such as multiple time trajectories of the variables). Since such applications demand the inference of directed relationships among variables in these non-linear systems, current methods that have a linear assumption on structure or yield undirected variable dependencies are insufficient. Hence, in this work, we present a methodology for structure discovery using an information-theoretic metric called directed time information (DTI). Using both synthetic dynamical systems as well as true biological datasets (kidney development and T-cell data), we demonstrate the utility of DTI in such problems.

  6. Integrated Three-Voltage-Booster DC-DC Converter to Achieve High Voltage Gain with Leakage-Energy Recycling for PV or Fuel-Cell Power Systems

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2015-09-01

    Full Text Available In this paper, an integrated three-voltage-booster DC-DC (direct current to direct current converter is proposed to achieve high voltage gain for renewable-energy generation systems. The proposed converter integrates three voltage-boosters into one power stage, which is composed of an active switch, a coupled-inductor, five diodes, and five capacitors. As compared with conventional high step-up converters, it has a lower component count. In addition, the features of leakage-energy recycling and switching loss reduction can be accomplished for conversion efficiency improvement. While the active switch is turned off, the converter can inherently clamp the voltage across power switch and suppress voltage spikes. Moreover, the reverse-recovery currents of all diodes can be alleviated by leakage inductance. A 200 W prototype operating at 100 kHz switching frequency with 36 V input and 400 V output is implemented to verify the theoretical analysis and to demonstrate the feasibility of the proposed high step-up DC-DC converter.

  7. Directing orbits of chaotic systems by particle swarm optimization

    International Nuclear Information System (INIS)

    Liu Bo; Wang Ling; Jin Yihui; Tang Fang; Huang Dexian

    2006-01-01

    This paper applies a novel evolutionary computation algorithm named particle swarm optimization (PSO) to direct the orbits of discrete chaotic dynamical systems towards desired target region within a short time by adding only small bounded perturbations, which could be formulated as a multi-modal numerical optimization problem with high dimension. Moreover, the synchronization of chaotic systems is also studied, which can be dealt with as an online problem of directing orbits. Numerical simulations based on Henon Map demonstrate the effectiveness and efficiency of PSO, and the effects of some parameters are also investigated

  8. Application of GIS in foreign direct investment decision support system

    Science.gov (United States)

    Zhou, Jianlan; Sun, Koumei

    2007-06-01

    It is important to make decisions on how to attract foreign direct investment (FDI) to China and know how the inequality of FDI introduction by locational different provinces. Following background descriptions on China's FDI economic environments and FDI-related policies, this paper demonstrates the uses of geographical information system (GIS) and multi-criterion decision-making (MCDM) framework in solving a spatial multi-objective problem of evaluating and ranking China's provinces for FDI introduction. It implements a foreign direct investment decision support system, which reveals the main determinants of FDI in China and gives some results of regional geographical analysis over spatial data.

  9. Experimental investigation of a directionally enhanced DHX concept for high temperature Direct Reactor Auxiliary Cooling Systems

    International Nuclear Information System (INIS)

    Hughes, Joel T.; Blandford, Edward D.

    2016-01-01

    Highlights: • A novel directional heat exchanger design has been developed. • Hydrodynamic tests have been performed on the proposed design. • Heat transfer performance is inferred by hydrodynamic results. • Results are discussed and future work is suggested. - Abstract: The use of Direct Reactor Auxiliary Cooling Systems (DRACSs) as a safety-related decay heat removal system for advanced reactors has developed historically through the Sodium Fast Reactor (SFR) community. Beginning with the EBR-II, DRACSs have been utilized in a large number of past and current SFR designs. More recently, the DRACS has been adopted for Fluoride Salt-Cooled High-Temperature Reactors (FHRs) for similar decay heat removal functions. In this paper we introduce a novel directionally enhanced DRACS Heat Exchanger (DHX) concept. We present design options for optimizing such a heat exchanger so that shell-side heat transfer is enhanced in one primary coolant flow direction and degraded in the opposite coolant flow direction. A reduced-scale experiment investigating the hydrodynamics of a directionally enhanced DHX was built and the data collected is presented. The concept of thermal diodicity is expanded to heat exchanger technologies and used as performance criteria for evaluating design options. A heat exchanger that can perform as such would be advantageous for use in advanced reactor concepts where primary coolant flow reversal is expected during Loss-of-Forced-Circulation (LOFC) accidents where the ability to circulate coolant is compromised. The design could also find potential use in certain advanced Sodium Fast Reactor (SFR) designs utilizing fluidic diode concepts.

  10. Experimental investigation of a directionally enhanced DHX concept for high temperature Direct Reactor Auxiliary Cooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Joel T.; Blandford, Edward D., E-mail: edb@unm.edu

    2016-07-15

    Highlights: • A novel directional heat exchanger design has been developed. • Hydrodynamic tests have been performed on the proposed design. • Heat transfer performance is inferred by hydrodynamic results. • Results are discussed and future work is suggested. - Abstract: The use of Direct Reactor Auxiliary Cooling Systems (DRACSs) as a safety-related decay heat removal system for advanced reactors has developed historically through the Sodium Fast Reactor (SFR) community. Beginning with the EBR-II, DRACSs have been utilized in a large number of past and current SFR designs. More recently, the DRACS has been adopted for Fluoride Salt-Cooled High-Temperature Reactors (FHRs) for similar decay heat removal functions. In this paper we introduce a novel directionally enhanced DRACS Heat Exchanger (DHX) concept. We present design options for optimizing such a heat exchanger so that shell-side heat transfer is enhanced in one primary coolant flow direction and degraded in the opposite coolant flow direction. A reduced-scale experiment investigating the hydrodynamics of a directionally enhanced DHX was built and the data collected is presented. The concept of thermal diodicity is expanded to heat exchanger technologies and used as performance criteria for evaluating design options. A heat exchanger that can perform as such would be advantageous for use in advanced reactor concepts where primary coolant flow reversal is expected during Loss-of-Forced-Circulation (LOFC) accidents where the ability to circulate coolant is compromised. The design could also find potential use in certain advanced Sodium Fast Reactor (SFR) designs utilizing fluidic diode concepts.

  11. Direct vessel inclined injection system for reduction of emergency core coolant direct bypass in advanced reactors

    International Nuclear Information System (INIS)

    Yoon, Sang H.; Lee, Jong G.; Suh, Kune Y.

    2006-01-01

    Multidimensional thermal hydraulics in the APR1400 (Advanced Power Reactor 1400 MWe) downcomer during a large-break loss-of-coolant accident (LBLOCA) plays a pivotal role in determining the capability of the safety injection system. APR1400 adopts the direct vessel injection (DVI) method for more effective core penetration of the emergency core cooling (ECC) water than the cold leg injection (CLI) method in the OPR1000 (Optimized Power Reactor 1000 MWe). The DVI method turned out to be prone to occasionally lack in efficacious delivery of ECC to the reactor core during the reflood phase of a LBLOCA, however. This study intends to demonstrate a direct vessel inclined injection (DVII) method, one of various ideas with which to maximize the ECC core penetration and to minimize the direct bypass through the break during the reflood phase of a LBLOCA. The 1/7 scaled down THETA (Transient Hydrodynamics Engineering Test Apparatus) tests show that a vertical inclined nozzle angle of the DVII system increases the downward momentum of the injected ECC water by reducing the degree of impingement on the reactor downcomer, whereby lessening the extent of the direct bypass through the break. The proposed method may be combined with other innovative measures with which to ensure an enough thermal margin in the core during the course of a LBLOCA in APR1400

  12. Directivity measurements in aluminum using a laser ultrasonics system

    International Nuclear Information System (INIS)

    Sakamoto, J M S; Pacheco, G M; Tittmann, B R; Baba, A

    2011-01-01

    A laser ultrasonics system was setup to measure the directivity (angular dependence pattern) of the amplitude of ultrasonic waves generated in aluminum samples. A pulsed Nd:YAG laser operating at 1064 nm optical wavelength, with typical pulse width (FWHM) of 8 ns, and energy per pulse of 450 mJ, was used to generate the ultrasound waves in the samples. The laser detection system was a Mach-Zehnder interferometer with typical noise-limited resolution of 0.25 nm (rms), frequency range from 50 kHz to 20 MHz, and measurement range from -75 nm/V to +75 nm/V. Two different optical spot sizes of the Nd:YAG laser were used to generate waves in the ablation regime: one was focused and the other was unfocused. Using the obtained data, the directivity graphics were drawn and compared with the theoretical curves, showing a good agreement. The experiments showed the directivity as a function of the optical spot size. For a point ultrasonic source (or focused optical spot), the directivity shows that the longitudinal waves present considerable amplitude in all directions. For a larger ultrasonic source (or an unfocused optical spot) the directivity shows that the longitudinal waves are generated with the higher amplitudes inside angles around ±10 0 .

  13. Direct Energy Centre underground parking integrated light control system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    LightSavers is a project undertaken by the Toronto Atmospheric Fund to accelerate the use of lighting technologies. As part of the project a pilot test has been carried out in the Direct Energy Center in Toronto. The aim of this report is to present the study and its results. The Direct Energy Center is a large event facility with an large underground parking facility. A lighting energy management system, the energy control system (ECS), capable of adjusting lighting levels based on occupancy was implemented in the centre and data was collected during over one year. Results showed that the ECS permitted a reduction in energy consumption and thus greenhouse gas emissions by 47% and the payback will take less than 6 years. This project demonstrated that the energy control system provides better energy, environmental and economic performance than a traditional automation system.

  14. DIRECTION OF MODERNIZATION OF THE ARCTIC MARINE TRANSPORTATION SYSTEM

    Directory of Open Access Journals (Sweden)

    N. I. Komkov

    2014-01-01

    Full Text Available The article deals with the modern processes of formation and development of the marine transportation system in the Russian Arctic, analyzes its problem areas and reserves growth. Shows the status and prospects of development of cargo specialized fl eet of ice-class and icebreakers. Particular attention is paid to infrastructure, port management, port The possibility of creating special economic zones. Systematized direction of modernization of the Arctic marine transportation system.

  15. A Tactical Database for the Low Cost Combat Direction System

    Science.gov (United States)

    1990-12-01

    A Tactical Database for the Low Cost Combat Direction System by Everton G. de Paula Captain, Brazilian Air Force B.S., Instituto Tecnologico de...objects as a unit. The AVANCE object management system [Ref. 29] uses the timestamp 156 model (pessimistic approach) for concurrency control. The Vbase...are no longer used). In AVANCE [Ref. 291, garbage collection is performed on user request. In GemStone [Ref. 25], garbage collection is executed in

  16. Analysis of Non-Uniform Gain for Control of a Deformable Mirror in an Adaptive-Optics System

    National Research Council Canada - National Science Library

    Vitayaudom, Kevin P

    2008-01-01

    The objective of this research was to develop and experimentally verify the use of spatially varying gain maps on the servo-loop controller of a deformable mirror for improvements in the performance...

  17. Solar radiation and cooling load calculation for radiant systems: Definition and evaluation of the Direct Solar Load

    DEFF Research Database (Denmark)

    Causone, Francesco; Corgnati, Stefano P.; Filippi, Marco

    2010-01-01

    The study of the influence of solar radiation on the built environment is a basic issue in building physics and currently it is extremely important because glazed envelopes are widely used in contemporary architecture. In the present study, the removal of solar heat gains by radiant cooling systems...... is investigated. Particular attention is given to the portion of solar radiation converted to cooling load, without taking part in thermal absorption phenomena due to the thermal mass of the room. This specific component of the cooling load is defined as the Direct Solar Load. A simplified procedure to correctly...... calculate the magnitude of the Direct Solar Load in cooling load calculations is proposed and it is implemented with the Heat Balance method and the Radiant Time Series method. The F ratio of the solar heat gains directly converted to cooling load, in the case of a low thermal mass radiant ceiling...

  18. Experiences Gained from Independent Assessment in Licensing of Advanced I and C Systems in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Lindner, Arndt B.; Wach, Dieter H.

    2003-01-01

    Operational benefits and enlarged functionality of modern technology, but also the physical and the technological aging of conventional instrumentation and control (I and C) systems, are motivations for modernization of I and C systems in nuclear power plants (NPPs). In case of safety-relevant I and C systems, the licensing authorities require the demonstration of sufficient safety of the systems.In several countries ongoing research and development projects are directed to provide a scientific basis and engineering solutions for cost-effective assessment of software-based I and C systems important to safety in NPPs. International initiatives have been started to develop a harmonized safety assessment methodology. The Institute for Safety Technology (ISTec) has been engaged in national and international programs as well as in establishing a two-phase qualification approach, which comprises a generic plant-independent qualification of hardware and software components and a plant-specific system qualification phase.In both generic qualification and plant-specific system qualification, ISTec has been involved as an independent third-party assessor for the relevant state authority. This paper reports experiences from the ISTec involvement in the assessment projects, e.g., in the assessment of the I and C important to safety in the new German High-Flux Research Reactor (FRM-2) in Munich and in the assessments of I and C modernization in NPPs of foreign countries (Bohunice, Slovak Republic; Paks, Hungary; and others). Conclusions are drawn from the experiences with respect to the practicability of the two-phase qualification concept and from the major findings in the plant-specific I and C assessments

  19. A Tiered Approach to Retinopathy of Prematurity Screening (TARP) Using a Weight Gain Predictive Model and a Telemedicine System.

    Science.gov (United States)

    Gurwin, Jaclyn; Tomlinson, Lauren A; Quinn, Graham E; Ying, Gui-Shuang; Baumritter, Agnieshka; Binenbaum, Gil

    2017-01-05

    The Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) Study telemedicine system of remote fundus image grading and The Children's Hospital of Philadelphia Retinopathy of Prematurity (CHOP-ROP) postnatal weight gain predictive model are 2 approaches for improving ROP screening efficiency. Current screening has low specificity for severe ROP. To describe a tiered approach to ROP screening (TARP) for identifying children who develop severe ROP using telemedicine and a predictive model synergistically. This investigation was a post hoc analysis of a cohort in the e-ROP Study (a multicenter prospective telemedicine study) and the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study (a multicenter retrospective cohort study). The setting was neonatal intensive care units at The Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania. Participants in the e-ROP Study were premature infants with a birth weight less than 1251 g and a known ROP outcome enrolled between May 25, 2011, and October 31, 2013. The G-ROP Study enrolled all infants undergoing ROP examinations with a known ROP outcome who were born between January 1, 2006, and December 31, 2011. The mean outcomes were the sensitivity for type 1 ROP, reductions in infants requiring imaging or examinations, numbers of imaging sessions and examinations, and total clinical encounters (imaging sessions and examinations combined). The following 4 screening approaches were evaluated: ROUTINE (only diagnostic examinations by an ophthalmologist), CHOP-ROP (birth weight and gestational age, with weekly weight gain initiating examinations when the risk cut point is surpassed), e-ROP IMAGING (trained reader grading of type 1 or 2 ROP initiates diagnostic examinations), and TARP (CHOP-ROP alarm initiates imaging, and imaging finding of severe ROP initiates diagnostic examinations). A total of 242 infants were included in the study, with a median birth

  20. Direct fed microbial supplementation repartitions host energy to the immune system.

    Science.gov (United States)

    Qiu, R; Croom, J; Ali, R A; Ballou, A L; Smith, C D; Ashwell, C M; Hassan, H M; Chiang, C-C; Koci, M D

    2012-08-01

    Direct fed microbials and probiotics are used to promote health in livestock and poultry; however, their mechanism of action is still poorly understood. We previously reported that direct fed microbial supplementation in young broilers reduced ileal respiration without changing whole-body energy expenditure. The current studies were conducted to further investigate the effects of a direct fed microbial on energy metabolism in different tissues of broilers. One hundred ninety-two 1-d-old broiler chicks (16 chicks/pen) were randomly assigned to 2 dietary groups: standard control starter diet (CSD) and CSD plus direct fed microbial (DFMD; 0.3%) with 6 pens/treatment. Body weight, feed consumption, whole-body energy expenditure, organ mass, tissue respiration rates, and peripheral blood mononuclear cell (PBMC) ATP concentrations were measured to estimate changes in energy metabolism. No differences in whole body energy expenditure or BW gain were observed; however, decreased ileal O(2) respiration (P energy consumption by PBMC corresponded with an altered immune response, broilers were immunized with sheep red blood cells (SRBC) and assayed for differences in their humoral response. The DFMD-fed broilers had a faster rate of antigen specific IgG production (P direct fed microbial used in this study resulted in energy re-partitioning to the immune system and an increase in antibody production independent of changes in whole body metabolism or growth performance.

  1. Direct energy conversion system for D-3He fusion

    International Nuclear Information System (INIS)

    Tomita, Y.; Shu, L.Y.; Momota, H.

    1993-11-01

    A novel and highly efficient direct energy conversion system is proposed for utilizing D- 3 He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to 'LINAC.' The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DECs bring about the high efficient fusion plant. (author)

  2. Future directions and emerging techniques for ISOL systems

    International Nuclear Information System (INIS)

    Talbert, W.L. Jr.; Bunker, M.E.

    1986-01-01

    The current status and future promise of ISOL systems are discussed, with emphasis on newly conceived experimental capabilities and interests. In addition to studies of nuclear structure using traditional or new on-line approaches, such as on-line nuclear orientation, the possibilities for studies with accelerated radioactive beams that have direct application to basic problems in materials science and astrophysics as well as to nuclear theory are pointed out. 43 refs., 3 figs., 1 tab

  3. Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

    OpenAIRE

    Jakub Ehrenberger; Jan Švec

    2017-01-01

    This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordinat...

  4. Thermodynamic analysis of a directly heated oxyfuel supercritical power system

    International Nuclear Information System (INIS)

    Chowdhury, A.S.M. Arifur; Bugarin, Luz; Badhan, Antara; Choudhuri, Ahsan; Love, Norman

    2016-01-01

    Highlights: • A thermodynamic analysis of a supercritical power cycle is presented. • The supercritical power cycle is modeled using ASPEN HYSYS®. • A liquid methane and oxygen feed system is more efficient than a gaseous system. • CO_2 recirculated in gas form is 10.6% more efficient than when in liquid form. • Commercially available technologies permit liquid feed system delivery. - Abstract: Directly heated supercritical oxy-fuel gas turbines have potential to provide a higher thermal efficiency and lower pollutant emissions compared to current gas turbine systems. Motivated by the advantages of an oxyfuel-based directly heated supercritical power system, this paper presents an analysis of different operating conditions using ASPEN HYSYS®. This study first investigates the efficiency of gaseous or liquid methane and oxygen feed systems. T-s and P-v diagrams are generated and compared to each other to determine which is more efficient. The analysis revealed that the entropy generated during the combustion process for a liquid feed system is approximately three times higher than when methane and oxygen are compressed in gaseous form and delivered to the combustor and burned. To mitigate the high temperatures (3300 K) of the methane and oxygen combustion reaction, carbon dioxide is recirculated. For this portion of the system, the use of gaseous and liquid carbon dioxide recirculation loops and their corresponding efficiencies are determined. The investigation shows that the system yielded a higher net efficiency of 55.1% when gaseous carbon dioxide is recirculated as a diluent with liquid methane and oxygen delivery to the combustor.

  5. Comparison between iterative wavefront control algorithm and direct gradient wavefront control algorithm for adaptive optics system

    Science.gov (United States)

    Cheng, Sheng-Yi; Liu, Wen-Jin; Chen, Shan-Qiu; Dong, Li-Zhi; Yang, Ping; Xu, Bing

    2015-08-01

    Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltages directly from wavefront slopes through pre-measuring the relational matrix between deformable mirror actuators and Hartmann wavefront sensor with perfect real-time characteristic and stability. However, with increasing the number of sub-apertures in wavefront sensor and deformable mirror actuators of adaptive optics systems, the matrix operation in direct gradient algorithm takes too much time, which becomes a major factor influencing control effect of adaptive optics systems. In this paper we apply an iterative wavefront control algorithm to high-resolution adaptive optics systems, in which the voltages of each actuator are obtained through iteration arithmetic, which gains great advantage in calculation and storage. For AO system with thousands of actuators, the computational complexity estimate is about O(n2) ˜ O(n3) in direct gradient wavefront control algorithm, while the computational complexity estimate in iterative wavefront control algorithm is about O(n) ˜ (O(n)3/2), in which n is the number of actuators of AO system. And the more the numbers of sub-apertures and deformable mirror actuators, the more significant advantage the iterative wavefront control algorithm exhibits. Project supported by the National Key Scientific and Research Equipment Development Project of China (Grant No. ZDYZ2013-2), the National Natural Science Foundation of China (Grant No. 11173008), and the Sichuan Provincial Outstanding Youth Academic Technology Leaders Program, China (Grant No. 2012JQ0012).

  6. Motion Planning for a Direct Metal Deposition Rapid Prototyping System

    Energy Technology Data Exchange (ETDEWEB)

    AMES,ARLO L.; HENSINGER,DAVID M.; KUHLMANN,JOEL L.

    1999-10-18

    A motion planning strategy was developed and implemented to generate motion control instructions from solid model data for controlling a robotically driven solid free-form fabrication process. The planning strategy was tested using a PUMA type robot arm integrated into a LENS{trademark} (Laser Engineered Net Shape) system. Previous systems relied on a series of x, y, and z stages, to provide a minimal coordinated motion control capability. This limited the complexity of geometries that could be constructed. With the coordinated motion provided by a robotic arm, the system can produce three dimensional parts by ''writing'' material onto any face of existing material. The motion planning strategy relied on solid model geometry evaluation and exploited robotic positioning flexibility to allow the construction of geometrically complex parts. The integration of the robotic manipulator into the LENS{trademark} system was tested by producing metal parts directly from CAD models.

  7. Slag processing system for direct coal-fired gas turbines

    Science.gov (United States)

    Pillsbury, Paul W.

    1990-01-01

    Direct coal-fired gas turbine systems and methods for their operation are provided by this invention. The gas turbine system includes a primary zone for burning coal in the presence of compressed air to produce hot combustion gases and debris, such as molten slag. The turbine system further includes a secondary combustion zone for the lean combustion of the hot combustion gases. The operation of the system is improved by the addition of a cyclone separator for removing debris from the hot combustion gases. The cyclone separator is disposed between the primary and secondary combustion zones and is in pressurized communication with these zones. In a novel aspect of the invention, the cyclone separator includes an integrally disposed impact separator for at least separating a portion of the molten slag from the hot combustion gases.

  8. Development of Blue Laser Direct-Write Lithography System

    Directory of Open Access Journals (Sweden)

    Hao-Wen Chang

    2012-01-01

    Full Text Available The optical lithography system researched in this study adopted the laser direct-write lithography technology with nano-positioning stage by using retailing blue ray optical pickup head contained 405nm wavelength and 0.85 numerical aperture of focus lens as the system lighting source. The system employed a photodiode received the focusing error signal reflected by the glass substrate to identify specimen position and automatic focused control with voice coil motor. The pattern substrate was loaded on a nano-positioning stage; input pattern path automatically and collocate with inner program at the same time. This research has successfully developed a blue laser lithography process system. The single spot size can be narrowed down to 3.07 μm and the linewidth is 3.3μm, time of laser control can reach to 450 ns and the exposure pattern can be controlled by program as well.

  9. Dynamic Sliding Mode Evolution PWM Controller for a Novel High-Gain Interleaved DC-DC Converter in PV System

    Directory of Open Access Journals (Sweden)

    Taizhou Bei

    2014-01-01

    Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.

  10. Parameter Improved Particle Swarm Optimization Based Direct-Current Vector Control Strategy for Solar PV System

    Directory of Open Access Journals (Sweden)

    NAMMALVAR, P.

    2018-02-01

    Full Text Available This paper projects Parameter Improved Particle Swarm Optimization (PIPSO based direct current vector control technology for the integration of photovoltaic array in an AC micro-grid to enhance the system performance and stability. A photovoltaic system incorporated with AC micro-grid is taken as the pursuit of research study. The test system features two power converters namely, PV side converter which consists of DC-DC boost converter with Perturbation and Observe (P&O MPPT control to reap most extreme power from the PV array, and grid side converter which consists of Grid Side-Voltage Source Converter (GS-VSC with proposed direct current vector control strategy. The gain of the proposed controller is chosen from a set of three values obtained using apriori test and tuned through the PIPSO algorithm so that the Integral of Time multiplied Absolute Error (ITAE between the actual and the desired DC link capacitor voltage reaches a minimum and allows the system to extract maximum power from PV system, whereas the existing d-q control strategy is found to perform slowly to control the DC link voltage under varying solar insolation and load fluctuations. From simulation results, it is evident that the proposed optimal control technique provides robust control and improved efficiency.

  11. Studies on energy gain of muon catalyzed hybrid D-D Reactor and it comparison to D-T system

    International Nuclear Information System (INIS)

    Eskandari, M.R.; Hoseine-Motlagh, S.N.; Faghihi, F.

    1998-01-01

    Regarding the advantages of hybrid fusion reactors, in most recent studies, the energy gain of muon catalyzed D-T hybrid reactors are studied. Knowing advantages of D-D fuel such as availability, not being radio-active, no tritium inventory requirement and transport problems, the muon catalyzed hybrid D-D reactor (μCHDDR) gain is calculated here for a given net reaction by solving its dynamical equations for various deuterium densities. It is shown theμCHDDR has advantages even for previously suggested similar D-T reactor

  12. Voltage Gain Derivation Based on Energy-Balanced Criterion for a Novel Hybrid-Input PV-Wind Power Conversion System

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2015-01-01

    Full Text Available This paper applies energy-balanced criterion to a novel hybrid-input PV-wind power conversion system (HPWPCS for voltage gain derivation. With the energy-balanced concept, complicated mathematical problems related to voltage gain derivation can be readily resolved. Based on the derived results, it is proven that the proposed HPWPCS is able to process two different kinds of renewable energy resources simultaneously. Even though the HPWPCS includes seven capacitors and three magnetic components, its voltage gain still can be found by the mathematical analysis. In the theoretical derivation, only the energy status of output inductor is dealt with such that complicated derivation procedure is avoided. This analysis method can also be applied to other hybrid green-energy conversion systems. In this paper, a 200 W 50 kHz prototype of HPWPCS is built and examined to verify the mathematical results.

  13. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  14. Development and deployment of the Collimated Directional Radiation Detection System

    Science.gov (United States)

    Guckes, Amber L.; Barzilov, Alexander

    2017-09-01

    The Collimated Directional Radiation Detection System (CDRDS) is capable of imaging radioactive sources in two dimensions (as a directional detector). The detection medium of the CDRDS is a single Cs2LiYCl6:Ce3+ scintillator cell enriched in 7Li (CLYC-7). The CLYC-7 is surrounded by a heterogeneous high-density polyethylene (HDPE) and lead (Pb) collimator. These materials make-up a coded aperture inlaid in the collimator. The collimator is rotated 360° by a stepper motor which enables time-encoded imaging of a radioactive source. The CDRDS is capable of spectroscopy and pulse shape discrimination (PSD) of photons and fast neutrons. The measurements of a radioactive source are carried out in discrete time steps that correlate to the angular rotation of the collimator. The measurement results are processed using a maximum likelihood expectation (MLEM) algorithm to create an image of the measured radiation. This collimator design allows for the directional detection of photons and fast neutrons simultaneously by utilizing only one CLYC-7 scintillator. Directional detection of thermal neutrons can also be performed by utilizing another suitable scintillator. Moreover, the CDRDS is portable, robust, and user friendly. This unit is capable of utilizing wireless data transfer for possible radiation mapping and network-centric applications. The CDRDS was tested by performing laboratory measurements with various gamma-ray and neutron sources.

  15. Direct encoding of orientation variance in the visual system.

    Science.gov (United States)

    Norman, Liam J; Heywood, Charles A; Kentridge, Robert W

    2015-01-01

    Our perception of regional irregularity, an example of which is orientation variance, seems effortless when we view two patches of texture that differ in this attribute. Little is understood, however, of how the visual system encodes a regional statistic like orientation variance, but there is some evidence to suggest that it is directly encoded by populations of neurons tuned broadly to high or low levels. The present study shows that selective adaptation to low or high levels of variance results in a perceptual aftereffect that shifts the perceived level of variance of a subsequently viewed texture in the direction away from that of the adapting stimulus (Experiments 1 and 2). Importantly, the effect is durable across changes in mean orientation, suggesting that the encoding of orientation variance is independent of global first moment orientation statistics (i.e., mean orientation). In Experiment 3 it was shown that the variance-specific aftereffect did not show signs of being encoded in a spatiotopic reference frame, similar to the equivalent aftereffect of adaptation to the first moment orientation statistic (the tilt aftereffect), which is represented in the primary visual cortex and exists only in retinotopic coordinates. Experiment 4 shows that a neuropsychological patient with damage to ventral areas of the cortex but spared intact early areas retains sensitivity to orientation variance. Together these results suggest that orientation variance is encoded directly by the visual system and possibly at an early cortical stage.

  16. Accelerating Genetic Gains in Legumes for the Development of Prosperous Smallholder Agriculture: Integrating Genomics, Phenotyping, Systems Modelling and Agronomy.

    Science.gov (United States)

    Varshney, Rajeev K; Thudi, Mahendar; Pandey, Manish K; Tardieu, Francois; Ojiewo, Chris; Vadez, Vincent; Whitbread, Anthony M; Siddique, Kadambot H M; Nguyen, Henry T; Carberry, Peter S; Bergvinson, David

    2018-03-05

    Grain legumes form an important component of the human diet, feed for livestock and replenish soil fertility through biological nitrogen fixation. Globally, the demand for food legumes is increasing as they complement cereals in protein requirements and possess a high percentage of digestible protein. Climate change has enhanced the frequency and intensity of drought stress that is posing serious production constraints, especially in rainfed regions where most legumes are produced. Genetic improvement of legumes, like other crops, is mostly based on pedigree and performance-based selection over the last half century. For achieving faster genetic gains in legumes in rainfed conditions, this review article proposes the integration of modern genomics approaches, high throughput phenomics and simulation modelling as support for crop improvement that leads to improved varieties that perform with appropriate agronomy. Selection intensity, generation interval and improved operational efficiencies in breeding are expected to further enhance the genetic gain in experiment plots. Improved seed access to farmers, combined with appropriate agronomic packages in farmers' fields, will deliver higher genetic gains. Enhanced genetic gains including not only productivity but also nutritional and market traits will increase the profitability of farmers and the availability of affordable nutritious food especially in developing countries.

  17. On the performance of mixed RF/FSO variable gain dual-hop transmission systems with pointing errors

    KAUST Repository

    Ansari, Imran Shafique

    2013-09-01

    In this work, the performance analysis of a dualhop relay transmission system composed of asymmetric radiofrequency (RF) and unified free-space optical (FSO) links subject to pointing errors is presented. These unified FSO links account for both types of detection techniques (i.e. indirect modulation/ direct detection (IM/DD) as well as heterodyne detection). More specifically, we derive new exact closed-form expressions for the cumulative distribution function, probability density function, moment generating function, and moments of the end-to-end signal-to-noise ratio of these systems in terms of the Meijer\\'s G function. We then capitalize on these results to offer new exact closed-form expressions for the outage probability, higherorder amount of fading, average error rate for binary and Mary modulation schemes, and ergodic capacity, all in terms of Meijer\\'s G functions. All our new analytical results are verified via computer-based Monte-Carlo simulations. Copyright © 2013 by the Institute of Electrical and Electronic Engineers, Inc.

  18. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

  19. Framework for Assessing Dynamic Nuclear Energy Systems for Sustainability: Final Report of the INPRO Collaborative Project GAINS

    International Nuclear Information System (INIS)

    2013-01-01

    One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world.' One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property'. The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. As an integral part of Phase 2 of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO), several collaborative projects (CPs) were established by INPRO members. The CP, 'Global Architecture of Innovative Nuclear Energy Systems Based on Thermal and Fast Reactors Including a Closed Fuel Cycle (GAINS)', was one of them. This CP was jointly implemented in 2008-2011 by Belgium, Canada, China, the Czech Republic, France, India, Italy, Japan, the Republic of Korea, the Russian Federation, Slovakia, Ukraine, the United States of America and the European Commission

  20. A change of direction in the Dutch health care system?

    Science.gov (United States)

    Lapré, R M

    1988-08-01

    The Dutch health care system seems to be undergoing a clear change of direction. The publication of the Report of the Committee of the Structure and Financing of the Health Care System is a prominent document which marks the emergence of a new trend. After an analysis of the characteristics of the Dutch health care system in the periods 1960-1975 and 1975-1985, an account is given of the most important proposals of the committee. The proposals clearly alter the trend towards more governmental involvement. They envisage a more market-oriented approach and freedom of operation while at the same time paying attention to aspects such as solidarity and social justice. The Committee's suggestions include the introduction of a basic insurance scheme for every citizen with a coverage determined by law, and in addition a voluntary supplementary insurance scheme in which the insured can decide what coverage he requires and that the insurer is obliged to accept him. The fact that there is a certain amount of agreement, at least over the direction that the strategy for change should take, justifies the expectation that many of the committee's proposals will be implemented.

  1. Direct coupling of a solar-hydrogen system in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arriaga, L.G. [Gerencia de Energias No Convencionales, Instituto de Investigaciones Electricas (IIE), Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico); Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S.C., Parque tecnologico Queretaro Sanfandila, Pedro Escobedo, C.P. 76703 Queretaro (Mexico); Martinez, W. [Departamento de Materiales Solares, CIE-UNAM, Av. Xochicalco s/n, Col. Centro, 62580 Temixco, Morelos (Mexico); Cano, U.; Blud, H. [Gerencia de Energias No Convencionales, Instituto de Investigaciones Electricas (IIE), Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)

    2007-09-15

    The scope of this article is to show the initial results obtained in the interconnection of a 2.7 kW solar panel system with a solid polymer electrolyte (SPE) electrolyzer. The Non-Conventional Energies Department (ENC) at the Electrical Research Institute (IIE) considers that the storage of this intermittent energy by a chemical element such as hydrogen can be advantageous for certain applications. One of the arguments is that unlike traditional battery systems, hydrogen presents the great advantage of not discharging its energy content as long as it is not used. The solar-hydrogen (S-H) system proposed consists of a commercial electrolyzer stack by Proton Energy Systems and a photovoltaic (PV) solar system of 36 panels (75 W each) of monocrystalline silicon (Siemens) interconnected in a configuration for 2.7 kW power at 48V{sub DC}. The complete electrolyzer (stack plus auxiliaries) has a maximum capacity of 1000lN/h of hydrogen with a power energy consumption of 8 kVA (220V{sub AC}, 32 A) and uses a stack of 25 cells of SPE with an energy consumption of 5.6 kW. We present voltage, current and energy consumption of the electrolyzer as a whole system and of the stack alone, as well as hydrogen quantification for the Hogen 40 operating in laboratory. These results allowed us to estimate the possibilities of coupling the electrolyzer stack alone, i.e. no auxiliaries nor power conditioning, with the solar PV system. Results such as I-E curves of the solar PV system obtained at different irradiances and temperatures, as well as I-E curve of SPE electrolyzer stack, gave direction for confirming that PV system configuration was sufficiently good to have the electrolyzer stack working near the maximum power point at a good range of irradiances ({proportional_to}600-800W/m{sup 2}). (author)

  2. Estimation of the Ideal Binary Mask using Directional Systems

    DEFF Research Database (Denmark)

    Boldt, Jesper; Kjems, Ulrik; Pedersen, Michael Syskind

    2008-01-01

    The ideal binary mask is often seen as a goal for time-frequency masking algorithms trying to increase speech intelligibility, but the required availability of the unmixed signals makes it difficult to calculate the ideal binary mask in any real-life applications. In this paper we derive the theory...... and the requirements to enable calculations of the ideal binary mask using a directional system without the availability of the unmixed signals. The proposed method has a low complexity and is verified using computer simulation in both ideal and non-ideal setups showing promising results....

  3. An analytical fuzzy-based approach to ?-gain optimal control of input-affine nonlinear systems using Newton-type algorithm

    Science.gov (United States)

    Milic, Vladimir; Kasac, Josip; Novakovic, Branko

    2015-10-01

    This paper is concerned with ?-gain optimisation of input-affine nonlinear systems controlled by analytic fuzzy logic system. Unlike the conventional fuzzy-based strategies, the non-conventional analytic fuzzy control method does not require an explicit fuzzy rule base. As the first contribution of this paper, we prove, by using the Stone-Weierstrass theorem, that the proposed fuzzy system without rule base is universal approximator. The second contribution of this paper is an algorithm for solving a finite-horizon minimax problem for ?-gain optimisation. The proposed algorithm consists of recursive chain rule for first- and second-order derivatives, Newton's method, multi-step Adams method and automatic differentiation. Finally, the results of this paper are evaluated on a second-order nonlinear system.

  4. Systemic Immunotherapy for Urothelial Cancer: Current Trends and Future Directions

    Directory of Open Access Journals (Sweden)

    Shilpa Gupta

    2017-01-01

    Full Text Available Urothelial cancer of the bladder, renal pelvis, ureter, and other urinary organs is the fifth most common cancer in the United States, and systemic platinum-based chemotherapy remains the standard of care for first-line treatment of advanced/metastatic urothelial carcinoma (UC. Until recently, there were very limited options for patients who are refractory to chemotherapy, or do not tolerate chemotherapy due to toxicities and overall outcomes have remained very poor. While the role of immunotherapy was first established in non-muscle invasive bladder cancer in the 1970s, no systemic immunotherapy was approved for advanced disease until the recent approval of a programmed death ligand-1 (PD-L1 inhibitor, atezolizumab, in patients with advanced/metastatic UC who have progressed on platinum-containing regimens. This represents a significant milestone in this disease after a void of over 30 years. In addition to atezolizumab, a variety of checkpoint inhibitors have shown a significant activity in advanced/metastatic urothelial carcinoma and are expected to gain Food and Drug Administration (FDA approval in the near future. The introduction of novel immunotherapy agents has led to rapid changes in the field of urothelial carcinoma. Numerous checkpoint inhibitors are being tested alone or in combination in the first and subsequent-line therapies of metastatic disease, as well as neoadjuvant and adjuvant settings. They are also being studied in combination with radiation therapy and for non-muscle invasive bladder cancer refractory to BCG. Furthermore, immunotherapy is being utilized for those ineligible for firstline platinum-based chemotherapy. This review outlines the novel immunotherapy agents which have either been approved, or are currently being investigated in clinical trials in UC.

  5. Direct process estimation from tomographic data using artificial neural systems

    Science.gov (United States)

    Mohamad-Saleh, Junita; Hoyle, Brian S.; Podd, Frank J.; Spink, D. M.

    2001-07-01

    The paper deals with the goal of component fraction estimation in multicomponent flows, a critical measurement in many processes. Electrical capacitance tomography (ECT) is a well-researched sensing technique for this task, due to its low-cost, non-intrusion, and fast response. However, typical systems, which include practicable real-time reconstruction algorithms, give inaccurate results, and existing approaches to direct component fraction measurement are flow-regime dependent. In the investigation described, an artificial neural network approach is used to directly estimate the component fractions in gas-oil, gas-water, and gas-oil-water flows from ECT measurements. A 2D finite- element electric field model of a 12-electrode ECT sensor is used to simulate ECT measurements of various flow conditions. The raw measurements are reduced to a mutually independent set using principal components analysis and used with their corresponding component fractions to train multilayer feed-forward neural networks (MLFFNNs). The trained MLFFNNs are tested with patterns consisting of unlearned ECT simulated and plant measurements. Results included in the paper have a mean absolute error of less than 1% for the estimation of various multicomponent fractions of the permittivity distribution. They are also shown to give improved component fraction estimation compared to a well known direct ECT method.

  6. Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Kathyayani

    2011-10-04

    Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

  7. Should I Gain Weight?

    Science.gov (United States)

    ... Videos for Educators Search English Español Should I Gain Weight? KidsHealth / For Teens / Should I Gain Weight? ... something about it. Why Do People Want to Gain Weight? Some of the reasons people give for ...

  8. Data-Driven Predictive Direct Load Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Knudsen, Torben; Wisniewski, Rafal

    2015-01-01

    A predictive control using subspace identification is applied for the smart grid integration of refrigeration systems under a direct load control scheme. A realistic demand response scenario based on regulation of the electrical power consumption is considered. A receding horizon optimal control...... is proposed to fulfil two important objectives: to secure high coefficient of performance and to participate in power consumption management. Moreover, a new method for design of input signals for system identification is put forward. The control method is fully data driven without an explicit use of model...... against real data. The performance improvement results in a 22% reduction in the energy consumption. A comparative simulation is accomplished showing the superiority of the method over the existing approaches in terms of the load following performance....

  9. Sum-Rate Maximization of Coordinated Direct and Relay Systems

    DEFF Research Database (Denmark)

    Sun, Fan; Popovski, Petar; Thai, Chan

    2012-01-01

    Joint processing of multiple communication flows in wireless systems has given rise to a number of novel transmission techniques, notably the two-way relaying based on wireless network coding. Recently, a related set of techniques has emerged, termed coordinated direct and relay (CDR) transmissions......, where the constellation of traffic flows is more general than the two-way. Regardless of the actual traffic flows, in a CDR scheme the relay has a central role in managing the interference and boosting the overall system performance. In this paper we investigate the novel transmission modes, based...... on amplify-and-forward, that arise when the relay is equipped with multiple antennas and can use beamforming. We focus on one representative traffic type, with one uplink and one downlink users and consider the achievable sum-rate maximization relay beamforming. The beamforming criterion leads to a non...

  10. Active Learning for Directed Exploration of Complex Systems

    Science.gov (United States)

    Burl, Michael C.; Wang, Esther

    2009-01-01

    Physics-based simulation codes are widely used in science and engineering to model complex systems that would be infeasible to study otherwise. Such codes provide the highest-fidelity representation of system behavior, but are often so slow to run that insight into the system is limited. For example, conducting an exhaustive sweep over a d-dimensional input parameter space with k-steps along each dimension requires k(sup d) simulation trials (translating into k(sup d) CPU-days for one of our current simulations). An alternative is directed exploration in which the next simulation trials are cleverly chosen at each step. Given the results of previous trials, supervised learning techniques (SVM, KDE, GP) are applied to build up simplified predictive models of system behavior. These models are then used within an active learning framework to identify the most valuable trials to run next. Several active learning strategies are examined including a recently-proposed information-theoretic approach. Performance is evaluated on a set of thirteen synthetic oracles, which serve as surrogates for the more expensive simulations and enable the experiments to be replicated by other researchers.

  11. 21 CFR 862.1110 - Bilirubin (total or direct) test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bilirubin (total or direct) test system. 862.1110... Systems § 862.1110 Bilirubin (total or direct) test system. (a) Identification. A bilirubin (total or direct) test system is a device intended to measure the levels of bilirubin (total or direct) in plasma...

  12. Efficiency of metabolizable energy utilization for maintenance and gain and evaluation of Small Ruminant Nutrition System model in Santa Ines sheep

    Directory of Open Access Journals (Sweden)

    José Gilson Louzada Regadas Filho

    2011-11-01

    Full Text Available This study was carried out to estimate efficiencies of the utilization of metabolizable energy for maintenance (k m and weight gain (k g and to evaluate the Small Ruminant Nutrition System (SRNS model in predicting dry matter intake and average daily gain of growing Santa Ines sheep. Twenty-four non-castrated Santa Ines sheep, at 50 days of age and with average body weight of 13.00 ± 0.56 kg, respectively, were used. After a 10-day adaptation period, four animals were slaughtered to be used as reference for estimating initial empty body weight and body composition of the other animals. The remaining animals were distributed in a random block design, with the treatments consisting of diets containing different levels of metabolizable energy (2.08, 2.28, 2.47 and 2.69 Mcal/kg of DM, with five replicates. The metabolizable energy use efficiencies for maintenance and for weight gain were calculated from the relationship between the dietary net energy for maintenance and gain and ME concentration in the diets. Evaluation of the SRNS model was performed by adjustment of simple linear regression model between the predicted (independent variable and observed (dependent variable values. The estimated energy use efficiency for maintenance (k m was 0.70; and for gain weight (kg it showed to be inversely proportional to the increase of metabolizable energy concentration in the diet. The dry matter intake predicted by the SRNS model did not statistically differ from that observed, but the model overestimated the average daily gain by 5.18%. Those results can contribute to the construction of a database, which could be condensed into several others in a predictive model of performance and feed planning for sheep reared in Brazil.

  13. WE-E-18A-07: MAGIC: Multi-Acquisition Gain Image Correction for Mobile X-Ray Systems with Intrinsic Localization Crosshairs

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y; Sharp, G [Massachusetts General Hospital, Boston, MA (United States)

    2014-06-15

    Purpose: Gain calibration for X-ray imaging systems with movable flat panel detectors (FPD) and intrinsic crosshairs is a challenge due to the geometry dependence of the heel effect and crosshair artifact. This study aims to develop a gain correction method for such systems by implementing the multi-acquisition gain image correction (MAGIC) technique. Methods: Raw flat-field images containing crosshair shadows and heel effect were acquired in 4 different FPD positions with fixed exposure parameters. The crosshair region was automatically detected and substituted with interpolated values from nearby exposed regions, generating a conventional single-image gain-map for each FPD position. Large kernel-based correction was applied to these images to correct the heel effect. A mask filter was used to invalidate the original cross-hair regions previously filled with the interpolated values. A final, seamless gain-map was created from the processed images by either the sequential filling (SF) or selective averaging (SA) techniques developed in this study. Quantitative evaluation was performed based on detective quantum efficiency improvement factor (DQEIF) for gain-corrected images using the conventional and proposed techniques. Results: Qualitatively, the MAGIC technique was found to be more effective in eliminating crosshair artifacts compared to the conventional single-image method. The mean DQEIF over the range of frequencies from 0.5 to 3.5 mm-1 were 1.09±0.06, 2.46±0.32, and 3.34±0.36 in the crosshair-artifact region and 2.35±0.31, 2.33±0.31, and 3.09±0.34 in the normal region, for the conventional, MAGIC-SF, and MAGIC-SA techniques, respectively. Conclusion: The introduced MAGIC technique is appropriate for gain calibration of an imaging system associated with a moving FPD and an intrinsic crosshair. The technique showed advantages over a conventional single image-based technique by successfully reducing residual crosshair artifacts, and higher image quality

  14. Development of seismic isolation system in vertical direction

    International Nuclear Information System (INIS)

    Ohoka, Makoto; Horikiri, Morito

    1999-04-01

    A structure concept of vertical seismic isolation system which uses a common deck and a set of large dish springs was created in past studies. In this report, a series of dynamic tests on a small scale model of a common deck isolation structure were performed. The model was excited by random and seismic waves in the horizontal direction and 2-D excitation, horizontal and vertical, in order to identify the characteristics of isolation effect. The tests results are summarized as below. 1) This structure has three vibration mode. The second mode is rocking. 2) Rocking frequency depends on the excitation, for this structure has dish spring which contact with cylinders. Rocking damping varies from 2 to 8%, 3) Each mode's response peak frequency to 2-D(horizontal and vertical) excitation is almost the same the some to horizontal excitation. Vertical mode damping to 2-D excitation is about three times to horizontal excitation. 4) Isolation effect depends on a characteristics of frequency of input motion. The minimum response is to the Monju design seismic wave, soil shear wave:Vs=2000 m/sec, natural frequency of horizontal isolation in vertical direction:fv=20 Hz. A relative displacement is controlled. 5) A rocking angular displacement to 2-D excitation is about 2 times to 1-D excitation(vertical). However, it is about 1.2 E-4(rad), sufficiently small for a practical plant. (author)

  15. Beamforming Design for Coordinated Direct and Relay Systems

    DEFF Research Database (Denmark)

    Sun, Fan; De Carvalho, Elisabeth; Thai, Chan

    2012-01-01

    Joint processing of multiple communication flows in wireless systems has given rise to a number of novel transmission techniques, notably the two-way relaying based on wireless network coding. Recently, a related set of techniques has emerged, termed coordinated direct and relay (CDR) transmissions......, where the constellation of traffic flows is more general than the two-way. Regardless of the actual traffic flows, in a CDR scheme the relay has a central role in managing the interference. In this paper we investigate the novel transmission modes, based on amplify-and-forward, that arise when the relay...... an iterative solution, as well as derive an upper performance bound. The numerical results demonstrate a clear benefit from usage of multiple antennas at the relay node....

  16. Dosimetry and image quality assessment in a direct radiography system

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Bruno Beraldo; Paixao, Lucas; Nogueira, Maria do Socorro, E-mail: boliveira.mg@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Marcio Alves de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina. Dept. de Anatomia e Imagem; Teixeira, Maria Helena Araujo [Clinica Dra. Maria Helena Araujo Teixeira, Belo Horizonte, MG (Brazil)

    2014-11-15

    Objective: to evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms. Materials and methods: Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms. Results: considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values. Conclusion: the present study contributes to verify the equipment conformity as regards dose values and image quality. (author)

  17. Optical filtering in directly modulated/detected OOFDM systems.

    Science.gov (United States)

    Sánchez, C; Ortega, B; Wei, J L; Capmany, J

    2013-12-16

    This work presents a theoretical investigation on the performance of directly modulated/detected (DM/DD) optical orthogonal frequency division multiplexed (OOFDM) systems subject to optical filtering. The impact of both linear and nonlinear distortion effects are taken into account to calculate the effective signal-to-noise ratio of each subcarrier. These results are then employed to optimize the design parameters of two simple optical filtering structures: a Mach Zehnder interferometer and a uniform fiber Bragg grating, leading to a significant optical power budget improvement given by 3.3 and 3dB, respectively. These can be further increased to 5.5 and 4.2dB respectively when balanced detection configurations are employed. We find as well that this improvement is highly dependent on the clipping ratio.

  18. A Validation System for the Complex Event Processing Directives of the ATLAS Shifter Assistant Tool

    CERN Document Server

    Anders, Gabriel; The ATLAS collaboration; Kazarov, Andrei; Lehmann Miotto, Giovanna; Santos, Alejandro; Soloviev, Igor

    2015-01-01

    Complex Event Processing (CEP) is a methodology that combines data from different sources in order to identify events or patterns that need particular attention. It has gained a lot of momentum in the computing world in the past few years and is used in ATLAS to continuously monitor the behaviour of the data acquisition system, to trigger corrective actions and to guide the experiment’s operators. This technology is very powerful, if experts regularly insert and update their knowledge about the system’s behaviour into the CEP engine. Nevertheless, writing or modifying CEP directives is not trivial since the used programming paradigm is quite different with respect to what developers are normally familiar with. In order to help experts verify that the directives work as expected, we have thus developed a complete testing and validation environment. This system consists of three main parts: the first is the persistent storage of all relevant data streams that are produced during data taking, the second is a...

  19. On the performance of hybrid line of sight RF and RF-FSO fixed gain dual-hop transmission systems

    KAUST Repository

    Zedini, Emna; Ansari, Imran Shafique; Alouini, Mohamed-Slim

    2014-01-01

    with direct detection (IM/DD)). Selection combining (SC) and maximum ratio combining (MRC) diversity schemes are investigated. More specifically, for the SC method, we derive new unified closed-form expressions for the cumulative distribution function (CDF

  20. Application of matrix singular value properties for evaluating gain and phase margins of multiloop systems. [stability margins for wing flutter suppression and drone lateral attitude control

    Science.gov (United States)

    Mukhopadhyay, V.; Newsom, J. R.

    1982-01-01

    A stability margin evaluation method in terms of simultaneous gain and phase changes in all loops of a multiloop system is presented. A universal gain-phase margin evaluation diagram is constructed by generalizing an existing method using matrix singular value properties. Using this diagram and computing the minimum singular value of the system return difference matrix over the operating frequency range, regions of guaranteed stability margins can be obtained. Singular values are computed for a wing flutter suppression and a drone lateral attitude control problem. The numerical results indicate that this method predicts quite conservative stability margins. In the second example if the eigenvalue magnitude is used instead of the singular value, as a measure of nearness to singularity, more realistic stability margins are obtained. However, this relaxed measure generally cannot guarantee global stability.

  1. Gain scheduling using the Youla parameterization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    1999-01-01

    Gain scheduling controllers are considered in this paper. The gain scheduling problem where the scheduling parameter vector cannot be measured directly, but needs to be estimated is considered. An estimation of the scheduling vector has been derived by using the Youla parameterization. The use...... in connection with H_inf gain scheduling controllers....

  2. Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

    Directory of Open Access Journals (Sweden)

    Jakub Ehrenberger

    2017-09-01

    Full Text Available This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordination is designed, in which not only some, but all the required types of short-circuit contributions are taken into account. In radial systems, if the pickup currents are correctly chosen, protection coordination for maximum contributions is enough to ensure selectivity times for all the required short-circuit types. In distributed generation systems, due to different contributions flowing through the primary and selective protections, coordination for maximum contributions is not enough, but all the short-circuit types must be taken into account, and the protection coordination becomes a complex problem. A possible solution to the problem, based on an appropriately designed optimization, has been proposed in the paper. By repeating a simple optimization considering only one short-circuit type, the protection coordination considering all the required short-circuit types has been achieved. To show the importance of considering all the types of short-circuit contributions, setting optimizations with one (the highest and all the types of short-circuit contributions have been performed. Finally, selectivity time values are explored throughout the entire protected section, and both the settings are compared.

  3. Genetic gain and economic values of selection strategies including semen traits in three- and four-way crossbreeding systems for swine production.

    Science.gov (United States)

    González-Peña, D; Knox, R V; MacNeil, M D; Rodriguez-Zas, S L

    2015-03-01

    Four semen traits: volume (VOL), concentration (CON), progressive motility of spermatozoa (MOT), and abnormal spermatozoa (ABN) provide complementary information on boar fertility. Assessment of the impact of selection for semen traits is hindered by limited information on economic parameters. Objectives of this study were to estimate economic values for semen traits and to evaluate the genetic gain when these traits are incorporated into traditional selection strategies in a 3-tier system of swine production. Three-way (maternal nucleus lines A and B and paternal nucleus line C) and 4-way (additional paternal nucleus line D) crossbreeding schemes were compared. A novel population structure that accommodated selection for semen traits was developed. Three selection strategies were simulated. Selection Strategy I (baseline) encompassed selection for maternal traits: number of pigs born alive (NBA), litter birth weight (LBW), adjusted 21-d litter weight (A21), and number of pigs at 21 d (N21); and paternal traits: number of days to 113.5 kg (D113), backfat (BF), ADG, feed efficiency (FE), and carcass lean % (LEAN). Selection Strategy II included Strategy I and the number of usable semen doses per collection (DOSES), a function of the 4 semen traits. Selection Strategy III included Strategy I and the 4 semen traits individually. The estimated economic values of VOL, CON, MOT, ABN, and DOSES for 7 to 1 collections/wk ranged from $0.21 to $1.44/mL, $0.12 to $0.83/10 spermatozoa/mm, $0.61 to $12.66/%, -$0.53 to -$10.88/%, and $2.01 to $41.43/%, respectively. The decrease in the relative economic values of semen traits and DOSES with higher number of collections per wk was sharper between 1 and 2.33 collections/wk than between 2.33 and 7 collections/wk. The higher economic value of MOT and ABN relative to VOL and CON could be linked to the genetic variances and covariances of these traits. Average genetic gains for the maternal traits were comparable across strategies

  4. Absolute stability results for well-posed infinite-dimensional systems with applications to low-gain integral control

    NARCIS (Netherlands)

    Logemann, H; Curtain, RF

    2000-01-01

    We derive absolute stability results for well-posed infinite-dimensional systems which, in a sense, extend the well-known circle criterion to the case that the underlying linear system is the series interconnection of an exponentially stable well-posed infinite-dimensional system and an integrator

  5. Is a Multi-Hop Relay Scheme Gainful in an IEEE 802.22-Based Cognitive Radio System?

    Science.gov (United States)

    Shin, Jungchae; Lee, Dong-Kyu; Cho, Ho-Shin

    In this paper, we formulate a plan to operate multi-hop relays in IEEE 802.22-based cognitive radio (CR) systems and evaluate system performance to consider the propriety of a multi-hop relay scheme in CR systems. A centralized radio resource management and a simple deployment of relay stations (RSs) are assessed to make relay operations feasible under CR conditions. Simulation results show that the proposed multi-hop relay scheme significantly increases system throughput compared to a no-relay CR system as the incumbent user (IU) traffic gets heavier. Furthermore, the optimal number of hops can be determined given the traffic conditions.

  6. Gain calibration of n-XYTER 1.0 - a prototype readout ASIC for the silicon tracking system of the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sorokin, Iurii [Goethe Univ. Frankfurt am Main (Germany); Kiev Institute for Nuclear Research (Ukraine); Collaboration: CBM-Collaboration

    2013-07-01

    n-XYTER is a 128-channel readout ASIC which measures both the integral signal charge and the time of occurance. Due to its self-triggering design, high gain, high rate capability and bipolar front-end, the chip has found a use as a prototype readout for the Silicon Tracking System, Muon and Cherenkov detectors of the CBM experiment. It is also going to be applied in other projects in Darmstadt, Heidelberg and Dubna. To perform gain calibration of n-XYTER, reference charge pulses of a very small (down to 3000 e{sup -}), yet precisely known amplitude had to be generated. This was achieved by attenuating a voltage step to a sub-millivolt level and passing it through a tiny (1 pF) capacitor. Special care had to be taken to check for possible systematic errors in the measurements of the attenuation factor and of the coupling capacitance. In addition, the system had to be well shielded against RF pickup, the parasitic capacitances had to be minimized and ensured to stay invariable. Correct estimate of the systematic error was confirmed by performing a measurement with a different signal source - a planar silicon detector, exposed to γ-radiation of {sup 241}Am. Finally, the dominating error came from the channel-to-channel gain variation.

  7. Transformation of CLF to ISS-CLF for Nonlinear Systems with Disturbance and Construction of Nonlinear Robust Controller with L2 Gain Performance

    Directory of Open Access Journals (Sweden)

    Keizo Okano

    2014-01-01

    Full Text Available A new nonlinear control law for a class of nonlinear systems with disturbance is proposed. A control law is designed by transforming control Lyapunov function (CLF to input-to-state stability control Lyapunov function (ISS-CLF. The transformed CLF satisfies a Hamilton-Jacobi-Isaacs (HJI equation. The feedback system by the proposed control law has characteristics of L2 gain. Finally, it is shown by a numerical example that the proposed control law makes a controller by feedback linearization robust against disturbance.

  8. Weight Gain during Pregnancy

    Science.gov (United States)

    ... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... fitness > Weight gain during pregnancy Weight gain during pregnancy E-mail to a friend Please fill in ...

  9. Preventing Weight Gain

    Science.gov (United States)

    ... Local Programs Related Topics Diabetes Nutrition Preventing Weight Gain Language: English (US) Español (Spanish) Recommend on Facebook ... cancer. Choosing an Eating Plan to Prevent Weight Gain So, how do you choose a healthful eating ...

  10. Effect of simvastatin in the autonomic system is dependent on the increased gain/sensitivity of the baroreceptors

    Science.gov (United States)

    Moreira, Edson D; Mostarda, Cristiano T; Moraes-Silva, Ivana C; Ferreira, Janaina B; dos Santos, Fernando; Lacchini, Silvia; De Angelis, Kátia; Rodrigues, Bruno; Irigoyen, Maria Cláudia

    2013-01-01

    A number of mechanisms have been proposed to explain the pleiotropic effect of statin therapy to reduce sympathetic outflow in cardiovascular disease. We tested the hypothesis that statin treatment could improve baroreflex gain-sensitivity triggered by morphological adaptations in the mechanoreceptor site, thus reducing sympathetic activity, regardless of arterial pressure (AP) level reduction. Male spontaneously hypertensive rats (SHR) were divided into control (SHR, n = 8) and SHR-simvastatin (5 mg/kg/day, for 7 days) (SHR-S, n = 8). After treatment, AP, baroreflex sensitivity (BRS) in response to AP-induced changes, aortic depressor nerve activity, and spectral analyses of pulse interval (PI) and AP variabilities were performed. Internal and external carotids were prepared for morphoquantitative evaluation. Although AP was similar between groups, sympathetic modulation, represented by the low frequency band of PI (SHR: 6.84 ± 3.19 vs. SHR-S: 2.41 ± 0.96 msec2) and from systolic AP variability (SHR: 3.95 ± 0.36 vs. SHR-S: 2.86 ± 0.18 mmHg2), were reduced in treated animals. In parallel, simvastatin induced an increase of 26% and 21% in the number of elastic lamellae as well as a decrease of 9% and 25% in the carotid thickness in both, external and internal carotid, respectively. Moreover, improved baroreceptor function (SHR: 0.78 ± 0.03 vs. SHR-S: 1.06 ± 0.04% mv/mmHg) was observed in addition to a 115% increase in aortic depressor nerve activity in SHR-S rats. Therefore, our data suggest that the reduction of sympathetic outflow in hypertension by simvastatin treatment may be triggered by structural changes in the carotid arteries and increased BRS in response to an improvement of the baroreceptors discharge and consequently of the afferent pathway of the baroreflex arch. PMID:24303130

  11. On the performance of mixed RF/FSO variable gain dual-hop transmission systems with pointing errors

    KAUST Repository

    Ansari, Imran Shafique; Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2013-01-01

    In this work, the performance analysis of a dualhop relay transmission system composed of asymmetric radiofrequency (RF) and unified free-space optical (FSO) links subject to pointing errors is presented. These unified FSO links account for both

  12. 77 FR 52264 - Airworthiness Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems...

    Science.gov (United States)

    2012-08-29

    ... Airworthiness Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems (Type Certificate... Airworthiness Directive (AD): Hughes Helicopters Inc., and McDonnel Douglas Helicopter Systems (Type Certificate...

  13. 78 FR 18226 - Airworthiness Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems...

    Science.gov (United States)

    2013-03-26

    ... Airworthiness Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems (Type Certificate... directive (AD): 2013-05-16 Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems (Type...

  14. Efficiency gain of solid oxide fuel cell systems by using anode offgas recycle - Results for a small scale propane driven unit

    Science.gov (United States)

    Dietrich, Ralph-Uwe; Oelze, Jana; Lindermeir, Andreas; Spitta, Christian; Steffen, Michael; Küster, Torben; Chen, Shaofei; Schlitzberger, Christian; Leithner, Reinhard

    The transfer of high electrical efficiencies of solid oxide fuel cells (SOFC) into praxis requires appropriate system concepts. One option is the anode-offgas recycling (AOGR) approach, which is based on the integration of waste heat using the principle of a chemical heat pump. The AOGR concept allows a combined steam- and dry-reforming of hydrocarbon fuel using the fuel cell products steam and carbon dioxide. SOFC fuel gas of higher quantity and quality results. In combination with internal reuse of waste heat the system efficiency increases compared to the usual path of partial oxidation (POX). The demonstration of the AOGR concept with a 300 Wel-SOFC stack running on propane required: a combined reformer/burner-reactor operating in POX (start-up) and AOGR modus; a hotgas-injector for anode-offgas recycling to the reformer; a dynamic process model; a multi-variable process controller; full system operation for experimental proof of the efficiency gain. Experimental results proof an efficiency gain of 18 percentage points (η·POX = 23%, η·AOGR = 41%) under idealized lab conditions. Nevertheless, further improvements of injector performance, stack fuel utilization and additional reduction of reformer reformer O/C ratio and system pressure drop are required to bring this approach into self-sustaining operation.

  15. Ferritin nanocontainers that self-direct in synthetic polymer systems

    Science.gov (United States)

    Sengonul, Merih C.

    Currently, there are many approaches to introduce functionality into synthetic polymers. Among these, for example, are copolymerization, grafting, and blending methods. However, modifications made by such methods also change the thermodynamics and rheological properties of the polymer system of interest, and each new modification often requires a costly reoptimization of polymer processing. Such a reoptimalization would not be necessary if new functionality could be introduced via a container whose external surface is chemically and physically tuned to interact with the parent polymer. The contents of the container could then be changed without changing other important properties of the parent polymer. In this context this thesis project explores an innovative nanocontainer platform which can be introduced into phase-separating homopolymer blends. Ferritin is a naturally existing nanocontainer that can be used synthetically to package and selectively transport functional moieties to a particular phase that is either in the bulk or on the surface of a homopolymer blend system. The principal focus of this work centers on modifying the surface of wild ferritin to: (1) render modified ferritin soluble in a non-aqueous solvent; and (2) impart it with self-directing properties when exposed to a homopolymer blend surface or incorporated into the bulk of a homopolymer blend. Wild ferritin is water soluble, and this research project successfully modified wild ferritin by grafting either amine-functional poly(ethylene glycol) (PEG) or short-chain alkanes to carbodiimide activated carboxylate groups on ferritin's surface. Such modified ferritin is soluble in dichloromethane (DCM). Modification was confirmed by ion-exchange chromatography, zeta-potential measurements, and electrospray mass spectroscopy. FT-IR was used to quantify the extent of PEGylation of the reaction products through area ratios of the -C-O-C asymmetric stretching vibration of the grafted PEG chains to the

  16. Comprehending emergent systems phenomena through direct-manipulation animation

    Science.gov (United States)

    Aguirre, Priscilla Abel

    This study seeks to understand the type of interaction mode that best supports learning and comprehension of emergent systems phenomena. Given that the literature has established that students hold robust misconceptions of such phenomena, this study investigates the influence of using three types of interaction; speed-manipulation animation (SMN), post-manipulation animation (PMA) and direct-manipulation animation (DMA) for increasing comprehension and testing transfer of the phenomena, by looking at the effect of simultaneous interaction of haptic and visual channels on long term and working memories when seeking to comprehend emergent phenomena. The questions asked were: (1) Does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool (i.e., SMA, PMA or DMA), improve students' mental model construction of systems, thus increasing comprehension of this scientific concept? And (2) does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool, give the students the necessary complex cognitive skill which can then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios? In an empirical study undergraduate and graduate students were asked to participate in one of three experimental conditions: SMA, PMA, or DMA. The results of the study found that it was the participants of the SMA treatment condition that had the most improvement in post-test scores. Students' understanding of the phenomena increased most when they used a dynamic model with few interactive elements (i.e., start, stop, and speed) that allowed for real time visualization of one's interaction on the phenomena. Furthermore, no indication was found that the learning of emergent phenomena, with the aid of a dynamic interactive modeling tool, gave the students the necessary complex cognitive skill which could then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios

  17. A Validation System for the Complex Event Processing Directives of the ATLAS Shifter Assistant Tool

    CERN Document Server

    Santos, Alejandro; The ATLAS collaboration; Avolio, Giuseppe; Kazarov, Andrei; Lehmann Miotto, Giovanna; Soloviev, Igor

    2015-01-01

    Complex Event Processing (CEP) is a methodology that combines data from many sources in order to identify events or patterns that need particular attention. It has gained a lot of momentum in the computing world in the past few years and is used in ATLAS to continuously monitor the behaviour of the data acquisition system, to trigger corrective actions and to guide the experiment’s operators. This technology is very powerful, if experts regularly insert and update their knowledge about the system’s behaviour into the CEP engine. Nevertheless, writing or modifying CEP rules is not trivial since the used programming paradigm is quite different with respect to what developers are normally familiar with. In order to help experts verify that the directives work as expected, we have thus developed a complete testing and validation environment. This system consists of three main parts: the first is the data reader from existing storage of all relevant data streams that are produced during data taking, the second...

  18. 31 CFR 363.0 - What is the TreasuryDirect ® system?

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What is the TreasuryDirect ® system? 363.0 Section 363.0 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... HELD IN TREASURYDIRECT General § 363.0 What is the TreasuryDirect ® system? The TreasuryDirect system...

  19. Restraining Sodium Volatilization in the Ferric Bauxite Direct Reduction System

    Directory of Open Access Journals (Sweden)

    Wentao Hu

    2016-03-01

    Full Text Available Direct reduction is an emerging utilization technology of ferric bauxite. However, it requires much more sodium carbonate than ordinary bauxite does. The volatilization is one of the most significant parts of sodium carbonate consumption, as reported in previous studies. Based on the new direct reduction method for utilization of ferric bauxite, this paper has systematically investigated factors including heating temperature, heating time, and sodium carbonate dosage influencing sodium volatilization. For the purpose of reducing sodium volatilization, the Box–Benhken design was employed, and the possibility of separating iron and sodium after direct reduction was also investigated.

  20. On the performance of hybrid RF and RF/FSO fixed gain dual-hop transmission systems

    KAUST Repository

    Ansari, Imran Shafique; Alouini, Mohamed-Slim; Yilmaz, Ferkan

    2013-01-01

    -form expressions for the cumulative distribution function, probability density function, moment generating function, and moments of the end-to-end signal-to-noise ratio of these systems in terms of the Meijer's G function. We then capitalize on these results

  1. Performance evaluation of directly photovoltaic powered DC PM (direct current permanent magnet) motor – propeller thrust system

    International Nuclear Information System (INIS)

    Atlam, Ozcan; Kolhe, Mohan

    2013-01-01

    Photovoltaic (PV) powered directly coupled electro-mechanical system has wide applications (e.g. PV powered cooling fans in green houses, PV water pumping system, solar vehicles). The objective of this work is to analyse the operation of directly PV powered DC PM (direct current permanent magnet) motor – propeller system for selection of motor parameters. The performance of such system mainly depends on the incident solar radiation, operating cell temperature, DC motor and propeller load parameters. It is observed that the operating points of the PV DC PM motor – propeller system matches very closely with the maximum power points (MPPs) of the PV array, if the DC PM motor – propeller parameters have been properly selected. It is found that for a specific application of such type of system, matching of torque–speed operating points with respect to the maximum power points of PV array are very important. It is ascertained through results that the DC PM motor's armature resistance, magnetic field constant, starting current to overcome the starting torque and torque coefficient are the main parameters. In designing a PV powered DC PM motor for a specific application, selection of these parameters are important for maximum utilization of the PV array output. The results of this system are useful for designing of directly PV powered DC PM motor's for aerodynamic applications. - Highlights: • We analyse the performance of directly PV powered DC PM motor – propeller system. • We examine PV electro-mechanical system for selection of DC motor parameters. • Matching of torque–speed curve to maximum power points of PV array is important

  2. Experience gained in the process of the variable mass heat flow control implemented in the district heat supply system of the city of Gyor

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, F.; Milanovich, L.; Lelek, J.; Kekk, I. [District Heating LTD. of Gyor (Hungary)

    1996-11-01

    The district heating system of the city of Gyor is fed from a hot water boiler plant. The total heat demand for 23,000 residential homes and several public facilities is 260 MW. The variable mass flow control was implemented in 1991 through 1992. Design, preparatory job and the majority of implementation was carried out without external involvement. The paper presents historical background and brief project presentation which is followed by comparative presentation of the variable mass flow control and constant mass flow control. This comparative survey has been conducted on the basis of operating data for 1993 and those for 1988. In the conclusion the gained experience is summarized.

  3. Effect of treatment with natalizumab on ability to work in people with multiple sclerosis: productivity gain based on direct measurement of work capacity before and after 1 year of treatment.

    Science.gov (United States)

    Olofsson, Sara; Wickström, Anne; Häger Glenngård, Anna; Persson, Ulf; Svenningsson, Anders

    2011-10-01

    Sweden is a high endemic region for multiple sclerosis (MS), a neurologic disorder characterized by repeated inflammatory episodes affecting the CNS. The disease has its peak age of onset at approximately 30 years and affects women twice as often as men. The young age of onset makes MS one of the major causes of reduced capacity to work due to neurologic disease in Western society. Natalizumab (Tysabri®) is among the new generation of biologic drugs for the treatment of MS. Clinical studies have demonstrated that natalizumab is an effective treatment for preventing relapses and inflammatory activity. The aim of the study was to estimate the monetary value of treatment with natalizumab on the ability to work in patients with MS in Sweden, based on a direct measurement of weekly hours worked before and after 1 year of treatment with natalizumab. A sample of patients, consisting of all patients who had started treatment with natalizumab during the period June 2007-May 2008, was identified through the Swedish Multiple Sclerosis Register (SMSreg). Data about sex, age, disease severity, and disease duration were collected from the register. Data about type of work and work capacity (number of hours worked per week) were collected retrospectively through a postal questionnaire. The average hours worked per week was estimated at baseline (2 weeks before treatment started) and at follow-up (50 weeks after treatment started), and the change was assigned an economic value using the human capital approach. This study showed that after 50 weeks of treatment with natalizumab, people with MS increased their productivity by 3.3 hours per week on average (p productivity gain (p = 0.025 and p = 0.002, respectively). A shorter duration of illness and a lower age at the start of treatment were significantly associated with a greater productivity gain after 50 weeks of treatment with natalizumab, which indicates that it is more beneficial to initiate efficient therapy early

  4. Implementing Information Security Management System as a part of business processes : Where to gain competitive advantage for ISMS?

    OpenAIRE

    Flyktman, Jari

    2016-01-01

    The Idea and background to the study subject lies in the interest in security, leadership and organizational development. The research question was how to provide best practices to fit these all together in harmony. The objective was to help small and medium sized organizations to understand the multifaceted nature of cybersecurity and requirements for successful implementation of information security management system (ISMS). ISMS help companies to form the needed security structures in pra...

  5. Design of High Precise Focusing System in Laser Direct Writer

    International Nuclear Information System (INIS)

    Liang, Y Y; Tian, F; Luo, J B; Yang, G G

    2006-01-01

    In order to improve the accuracy and efficiency of fabricating lines with laser pattern generator, a novel focusing system was designed. Focusing system is based on optical off-axis detection principle. The detector is a two-quadrant photocell and the defocus signal is constructed by division. Focusing system has the character of second-order system with overdamp. The new embedded PID controller improves the performance of focusing system and upgrades the closed-loop precision to 0.2 μm. Furthermore focusing system has the fabrication capabilities for alterable-width lines under various defocus amount

  6. Application of multi-objective controller to optimal tuning of PID gains for a hydraulic turbine regulating system using adaptive grid particle swam optimization.

    Science.gov (United States)

    Chen, Zhihuan; Yuan, Yanbin; Yuan, Xiaohui; Huang, Yuehua; Li, Xianshan; Li, Wenwu

    2015-05-01

    A hydraulic turbine regulating system (HTRS) is one of the most important components of hydropower plant, which plays a key role in maintaining safety, stability and economical operation of hydro-electrical installations. At present, the conventional PID controller is widely applied in the HTRS system for its practicability and robustness, and the primary problem with respect to this control law is how to optimally tune the parameters, i.e. the determination of PID controller gains for satisfactory performance. In this paper, a kind of multi-objective evolutionary algorithms, named adaptive grid particle swarm optimization (AGPSO) is applied to solve the PID gains tuning problem of the HTRS system. This newly AGPSO optimized method, which differs from a traditional one-single objective optimization method, is designed to take care of settling time and overshoot level simultaneously, in which a set of non-inferior alternatives solutions (i.e. Pareto solution) is generated. Furthermore, a fuzzy-based membership value assignment method is employed to choose the best compromise solution from the obtained Pareto set. An illustrative example associated with the best compromise solution for parameter tuning of the nonlinear HTRS system is introduced to verify the feasibility and the effectiveness of the proposed AGPSO-based optimization approach, as compared with two another prominent multi-objective algorithms, i.e. Non-dominated Sorting Genetic Algorithm II (NSGAII) and Strength Pareto Evolutionary Algorithm II (SPEAII), for the quality and diversity of obtained Pareto solutions set. Consequently, simulation results show that this AGPSO optimized approach outperforms than compared methods with higher efficiency and better quality no matter whether the HTRS system works under unload or load conditions. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Gestational weight gain.

    Science.gov (United States)

    Kominiarek, Michelle A; Peaceman, Alan M

    2017-12-01

    Prenatal care providers are advised to evaluate maternal weight at each regularly scheduled prenatal visit, monitor progress toward meeting weight gain goals, and provide individualized counseling if significant deviations from a woman's goals occur. Today, nearly 50% of women exceed their weight gain goals with overweight and obese women having the highest prevalence of excessive weight gain. Risks of inadequate weight gain include low birthweight and failure to initiate breast-feeding whereas the risks of excessive weight gain include cesarean deliveries and postpartum weight retention for the mother and large-for-gestational-age infants, macrosomia, and childhood overweight or obesity for the offspring. Prenatal care providers have many resources and tools to incorporate weight and other health behavior counseling into routine prenatal practices. Because many women are motivated to improve health behaviors, pregnancy is often considered the optimal time to intervene for issues related to eating habits and physical activity to prevent excessive weight gain. Gestational weight gain is a potentially modifiable risk factor for a number of adverse maternal and neonatal outcomes and meta-analyses of randomized controlled trials report that diet or exercise interventions during pregnancy can help reduce excessive weight gain. However, health behavior interventions for gestational weight gain have not significantly improved other maternal and neonatal outcomes and have limited effectiveness in overweight and obese women. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. NASA's Earth Science Data Systems - Lessons Learned and Future Directions

    Science.gov (United States)

    Ramapriyan, Hampapuram K.

    2010-01-01

    In order to meet the increasing demand for Earth Science data, NASA has significantly improved the Earth Science Data Systems over the last two decades. This improvement is reviewed in this slide presentation. Many Earth Science disciplines have been able to access the data that is held in the Earth Observing System (EOS) Data and Information System (EOSDIS) at the Distributed Active Archive Centers (DAACs) that forms the core of the data system.

  9. The Gain-of-Function Integrin β3 Pro33 Variant Alters the Serotonin System in the Mouse Brain.

    Science.gov (United States)

    Dohn, Michael R; Kooker, Christopher G; Bastarache, Lisa; Jessen, Tammy; Rinaldi, Capria; Varney, Seth; Mazalouskas, Matthew D; Pan, Hope; Oliver, Kendra H; Velez Edwards, Digna R; Sutcliffe, James S; Denny, Joshua C; Carneiro, Ana M D

    2017-11-15

    Engagement of integrins by the extracellular matrix initiates signaling cascades that drive a variety of cellular functions, including neuronal migration and axonal pathfinding in the brain. Multiple lines of evidence link the ITGB3 gene encoding the integrin β3 subunit with the serotonin (5-HT) system, likely via its modulation of the 5-HT transporter (SERT). The ITGB3 coding polymorphism Leu33Pro (rs5918, Pl A2 ) produces hyperactive αvβ3 receptors that influence whole-blood 5-HT levels and may influence the risk for autism spectrum disorder (ASD). Using a phenome-wide scan of psychiatric diagnoses, we found significant, male-specific associations between the Pro33 allele and attention-deficit hyperactivity disorder and ASDs. Here, we used knock-in (KI) mice expressing an Itgb3 variant that phenocopies the human Pro33 variant to elucidate the consequences of constitutively enhanced αvβ3 signaling to the 5-HT system in the brain. KI mice displayed deficits in multiple behaviors, including anxiety, repetitive, and social behaviors. Anatomical studies revealed a significant decrease in 5-HT synapses in the midbrain, accompanied by decreases in SERT activity and reduced localization of SERTs to integrin adhesion complexes in synapses of KI mice. Inhibition of focal adhesion kinase (FAK) rescued SERT function in synapses of KI mice, demonstrating that constitutive active FAK signaling downstream of the Pro32Pro33 integrin αvβ3 suppresses SERT activity. Our studies identify a complex regulation of 5-HT homeostasis and behaviors by integrin αvβ3, revealing an important role for integrins in modulating risk for neuropsychiatric disorders. SIGNIFICANCE STATEMENT The integrin β3 Leu33Pro coding polymorphism has been associated with autism spectrum disorders (ASDs) within a subgroup of patients with elevated blood 5-HT levels, linking integrin β3, 5-HT, and ASD risk. We capitalized on these interactions to demonstrate that the Pro33 coding variation in the murine

  10. mathematical model for direct evaporative space cooling systems

    African Journals Online (AJOL)

    eobe

    of the sensible heat of the air is transferred to the water and becomes latent heat by evaporating some of the water. The latent heat follows the water vapour and diffuses into the air. In a DEC (direct evaporative cooling), the heat and mass transferred between air and water decreases the air dry bulb temperature (DBT) and ...

  11. Direct unavailability computation of a maintained highly reliable system

    Czech Academy of Sciences Publication Activity Database

    Briš, R.; Byczanski, Petr

    2010-01-01

    Roč. 224, č. 3 (2010), s. 159-170 ISSN 1748-0078 Grant - others:GA Mšk(CZ) MSM6198910007 Institutional research plan: CEZ:AV0Z30860518 Keywords : high reliability * availability * directed acyclic graph Subject RIV: BA - General Mathematics http:// journals .pepublishing.com/content/rtp3178l17923m46/

  12. 48 CFR 702.170-17 - Automated Directives System.

    Science.gov (United States)

    2010-10-01

    .... “Automated Directives System” (“ADS”) sets forth the Agency's policies and essential procedures, as well as supplementary informational references. It contains six functional series, interim policy updates, valid USAID handbook chapters, a resource library, and a glossary. References to “ADS” throughout this chapter 7 are...

  13. Distributed adaptive asymptotically consensus tracking control of uncertain Euler-Lagrange systems under directed graph condition.

    Science.gov (United States)

    Wang, Wei; Wen, Changyun; Huang, Jiangshuai; Fan, Huijin

    2017-11-01

    In this paper, a backstepping based distributed adaptive control scheme is proposed for multiple uncertain Euler-Lagrange systems under directed graph condition. The common desired trajectory is allowed totally unknown by part of the subsystems and the linearly parameterized trajectory model assumed in currently available results is no longer needed. To compensate the effects due to unknown trajectory information, a smooth function of consensus errors and certain positive integrable functions are introduced in designing virtual control inputs. Besides, to overcome the difficulty of completely counteracting the coupling terms of distributed consensus errors and parameter estimation errors in the presence of asymmetric Laplacian matrix, extra information transmission of local parameter estimates are introduced among linked subsystem and adaptive gain technique is adopted to generate distributed torque inputs. It is shown that with the proposed distributed adaptive control scheme, global uniform boundedness of all the closed-loop signals and asymptotically output consensus tracking can be achieved. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Development of prostate cancer research database with the clinical data warehouse technology for direct linkage with electronic medical record system.

    Science.gov (United States)

    Choi, In Young; Park, Seungho; Park, Bumjoon; Chung, Byung Ha; Kim, Choung-Soo; Lee, Hyun Moo; Byun, Seok-Soo; Lee, Ji Youl

    2013-01-01

    In spite of increased prostate cancer patients, little is known about the impact of treatments for prostate cancer patients and outcome of different treatments based on nationwide data. In order to obtain more comprehensive information for Korean prostate cancer patients, many professionals urged to have national system to monitor the quality of prostate cancer care. To gain its objective, the prostate cancer database system was planned and cautiously accommodated different views from various professions. This prostate cancer research database system incorporates information about a prostate cancer research including demographics, medical history, operation information, laboratory, and quality of life surveys. And, this system includes three different ways of clinical data collection to produce a comprehensive data base; direct data extraction from electronic medical record (EMR) system, manual data entry after linking EMR documents like magnetic resonance imaging findings and paper-based data collection for survey from patients. We implemented clinical data warehouse technology to test direct EMR link method with St. Mary's Hospital system. Using this method, total number of eligible patients were 2,300 from 1997 until 2012. Among them, 538 patients conducted surgery and others have different treatments. Our database system could provide the infrastructure for collecting error free data to support various retrospective and prospective studies.

  15. Novel Directional Protection Scheme for the FREEDM Smart Grid System

    Science.gov (United States)

    Sharma, Nitish

    This research primarily deals with the design and validation of the protection system for a large scale meshed distribution system. The large scale system simulation (LSSS) is a system level PSCAD model which is used to validate component models for different time-scale platforms, to provide a virtual testing platform for the Future Renewable Electric Energy Delivery and Management (FREEDM) system. It is also used to validate the cases of power system protection, renewable energy integration and storage, and load profiles. The protection of the FREEDM system against any abnormal condition is one of the important tasks. The addition of distributed generation and power electronic based solid state transformer adds to the complexity of the protection. The FREEDM loop system has a fault current limiter and in addition, the Solid State Transformer (SST) limits the fault current at 2.0 per unit. Former students at ASU have developed the protection scheme using fiber-optic cable. However, during the NSF-FREEDM site visit, the National Science Foundation (NSF) team regarded the system incompatible for the long distances. Hence, a new protection scheme with a wireless scheme is presented in this thesis. The use of wireless communication is extended to protect the large scale meshed distributed generation from any fault. The trip signal generated by the pilot protection system is used to trigger the FID (fault isolation device) which is an electronic circuit breaker operation (switched off/opening the FIDs). The trip signal must be received and accepted by the SST, and it must block the SST operation immediately. A comprehensive protection system for the large scale meshed distribution system has been developed in PSCAD with the ability to quickly detect the faults. The validation of the protection system is performed by building a hardware model using commercial relays at the ASU power laboratory.

  16. Development of a Waste Vault Directional Assay System (VDAS)

    Energy Technology Data Exchange (ETDEWEB)

    LaFleur, Adrienne Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-08

    We are developing a portable neutron and gamma detector called VDAS with sufficient sensitivity and directional capability such that it could operate in high gamma dose rate environments. This detector will be designed such that it can be remotely deployed and adaptable to a broad range of possible facility infrastructure to record a 3D array of gross neutron and gamma measurements, including axial and radial rotation, for identifying potential SNM material locations.

  17. A Single-Point Mooring System for Direct Pumpout of Hopper Dredges

    National Research Council Canada - National Science Library

    1992-01-01

    This technical note describes a direct pumpout (DPO) system for use with hopper dredges, operating and design criteria for the DPO, initial mooring system designs, and the final DPO and mooring system selected...

  18. System Views on Entrepreneurship – Going in the Right Direction?

    DEFF Research Database (Denmark)

    Christensen, Jesper Lindgaard

    2016-01-01

    The literature on National Systems of Entrepreneurship (NSE) (Acs et al., 2014, 2016) has been claimed to be an important strand of entrepreneurship literature. This paper takes stock of system perspectives on entrepreneurship including recent re-vitalizations of the concept. Based on literature ...

  19. Multiple criteria decision-making process to derive consensus desired genetic gains for a dairy cattle breeding objective for diverse production systems.

    Science.gov (United States)

    Kariuki, C M; van Arendonk, J A M; Kahi, A K; Komen, H

    2017-06-01

    Dairy cattle industries contribute to food and nutrition security and are a source of income for numerous households in many developing countries. Selective breeding can enhance efficiency in these industries. Developing dairy industries are characterized by diverse production and marketing systems. In this paper, we use weighted goal aggregating procedure to derive consensus trait preferences for different producer categories and processors. We based the study on the dairy industry in Kenya. The analytic hierarchy process was used to derive individual preferences for milk yield (MY), calving interval (CIN), production lifetime (PLT), mature body weight (MBW), and fat yield (FY). Results show that classical classification of production systems into large-scale and smallholder systems does not capture all differences in trait preferences. These differences became apparent when classification was based on productivity at the individual animal level, with high and low intensity producers and processors as the most important groups. High intensity producers had highest preferences for PLT and MY, whereas low intensity producers had highest preference for CIN and PLT; processors preferred MY and FY the most. The highest disagreements between the groups were observed for FY, PLT, and MY. Individual and group preferences were aggregated into consensus preferences using weighted goal programming. Desired gains were obtained as a product of consensus preferences and percentage genetic gains (G%). These were 2.42, 0.22, 2.51, 0.15, and 0.87 for MY, CIN, PLT, MBW, and FY, respectively. Consensus preferences can be used to derive a single compromise breeding objective for situations where the same genetic resources are used in diverse production and marketing circumstances. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license

  20. Direction of Radio Finding via MUSIC (Multiple Signal Classification) Algorithm for Hardware Design System

    Science.gov (United States)

    Zhang, Zheng

    2017-10-01

    Concept of radio direction finding systems, which use radio direction finding is based on digital signal processing algorithms. Thus, the radio direction finding system becomes capable to locate and track signals by the both. Performance of radio direction finding significantly depends on effectiveness of digital signal processing algorithms. The algorithm uses the Direction of Arrival (DOA) algorithms to estimate the number of incidents plane waves on the antenna array and their angle of incidence. This manuscript investigates implementation of the DOA algorithms (MUSIC) on the uniform linear array in the presence of white noise. The experiment results exhibit that MUSIC algorithm changed well with the radio direction.

  1. Coating system to permit direct brazing of ceramics

    Science.gov (United States)

    Cadden, Charles H.; Hosking, F. Michael

    2003-01-01

    This invention relates to a method for preparing the surface of a ceramic component that enables direct brazing using a non-active braze alloy. The present invention also relates to a method for directly brazing a ceramic component to a ceramic or metal member using this method of surface preparation, and to articles produced by using this brazing method. The ceramic can be high purity alumina. The method comprises applying a first coating of a silicon-bearing oxide material (e.g. silicon dioxide or mullite (3Al.sub.2 O.sub.3.2SiO.sub.2) to the ceramic. Next, a thin coating of active metal (e.g. Ti or V) is applied. Finally, a thicker coating of a non-active metal (e.g. Au or Cu) is applied. The coatings can be applied by physical vapor deposition (PVD). Alternatively, the active and non-active metals can be co-deposited (e.g. by sputtering a target made of mullite). After all of the coatings have been applied, the ceramic can be fired at a high temperature in a non-oxidizing environment to promote diffusion, and to enhance bonding of the coatings to the substrate. After firing, the metallized ceramic component can be brazed to other components using a conventional non-active braze alloy. Alternatively, the firing and brazing steps can be combined into a single step. This process can replace the need to perform a "moly-manganese" metallization step.

  2. Directive Nanophysical Cues for Regenerative Neural Cell Systems

    Science.gov (United States)

    Ayres, Virginia; Tiryaki, Volkan Mujdat; Ahmed, Ijaz; Shreiber, David

    Until recently, implantables such as stents, probes, wafers and scaffolds have been viewed as passive vehicles for the delivery of physical, pharmacological and cellular interventions. Recent research, however, indicates that the physical environments that implantables present supply directive cues in their own right that work in conjunction with biochemical cues and produce a jointly-directed outcome. We will present our research in CNS repairs using advanced scanning probe microscopy, electron microscopies and contact angle measurements to quantitatively describe the nanoscale elasticity, surface roughness, work of adhesion and surface polarity for investigation of scaffold environments. We will also present our research using super-resolution immunocytochemistry and atomic force microscopy to evaluate neural cell morphological responses with associated micro filament, microtubule and intermediate filament expressions, along with results on how and which integrin-family receptors are possibly involved. Finally, we will present our novel application of k-means cluster analysis applied across multiple experimental modalities for quantification of synergistic scaffold properties and cell responses.

  3. Mimicking directed binary networks for exploring systemic sensitivity: Is NCAA FBS a fragile competition system?

    Directory of Open Access Journals (Sweden)

    Fushing Hsieh

    2016-07-01

    Full Text Available Can a popular real-world competition system indeed be fragile? To address this question, we represent such a system by a directed binary network. Upon observed network data, typically in a form of win-and-loss matrix, our computational developments begin with collectively extracting network's information flows. And then we compute and discover network's macrostate. This computable macrostate is further shown to contain deterministic structures embedded with randomness mechanisms. Such coupled deterministic and stochastic components becomes the basis for generating the microstate ensemble. Specifically a network mimicking algorithm is proposed to generate a microstate ensemble by subject to the statistical mechanics principle: All generated microscopic states have to conform to its macrostate of the target system. We demonstrate that such a microstate ensemble is an effective platform for exploring systemic sensitivity. Throughout our computational developments, we employ the NCAA Football Bowl Subdivision (FBS as an illustrating example system. Upon this system, its macrostate is discovered by having a nonlinear global ranking hierarchy as its deterministic component, while its constrained randomness component is embraced within the nearly completely recovered conference schedule . Based on the computed microstate ensemble, we are able to conclude that the NCAA FBS is overall a fragile competition system because it retains highly heterogeneous degrees of sensitivity with its ranking hierarchy.

  4. Uncertain rule-based fuzzy systems introduction and new directions

    CERN Document Server

    Mendel, Jerry M

    2017-01-01

    The second edition of this textbook provides a fully updated approach to fuzzy sets and systems that can model uncertainty — i.e., “type-2” fuzzy sets and systems. The author demonstrates how to overcome the limitations of classical fuzzy sets and systems, enabling a wide range of applications from time-series forecasting to knowledge mining to control. In this new edition, a bottom-up approach is presented that begins by introducing classical (type-1) fuzzy sets and systems, and then explains how they can be modified to handle uncertainty. The author covers fuzzy rule-based systems – from type-1 to interval type-2 to general type-2 – in one volume. For hands-on experience, the book provides information on accessing MatLab and Java software to complement the content. The book features a full suite of classroom material. Presents fully updated material on new breakthroughs in human-inspired rule-based techniques for handling real-world uncertainties; Allows those already familiar with type-1 fuzzy se...

  5. AGRICULTURAL TAX SYSTEM IN POLAND AND DIRECTIONS OF THE CHANGES

    Directory of Open Access Journals (Sweden)

    Marzena Malewska

    2014-03-01

    Full Text Available A research problem taken in the article is a question, whether legal solutions applied in the Polish system of the taxation of agriculture have an appropriate shape and whether this system is optimal? If not, what are possible options of changes and whether the in-come tax is good for agricultural activities. A method of analysis of secondary sources was used in order to solve the research problem. Required data was taken from the base of the Główny Urząd Statystyczny and scientific publications of the publishing universi-ty. In the article were formulated the following hypotheses: 1.\tThe system of the taxation of agriculture is different than other existing Polish law and it is regarded as unfair in relation to other social groups. 2.\tChanging the tax system in agriculture is necessary and would lead to positive chang-es in the structure of agriculture. 3.\tThe reform of the taxation system of agricultural production is in many aspects neces-sary and beneficial, but it should nevertheless take into account the specificities of the agricultural activity. 4.\tThe introduction of the income tax has its bad side and carries the disadvantages for both farmers and municipalities.

  6. Global Positioning System: Political Support, Directions of Development, and Expectations

    Directory of Open Access Journals (Sweden)

    Krzysztof Czaplewski

    2015-06-01

    Full Text Available Over the last decade the Global Positioning System has become a global, multifunctional tool which provides services that are an integral part of U.S. national security as well as the security of other highly developed countries. Economic development, transport security as well as homeland security are important elements of the global economic infrastructure. In 2000 the United States acknowledged the growing significance of GPS for civilian users and stopped intentionally degrading accuracy for non-military signals that are known as “Selective Availability”. Since then, commercial applications of satellite systems have been proliferating even more rapidly, and therefore, their importance in everyday life has greatly increased. Currently, services that depend on information obtained from the Global Positioning System are the driving force behind economic growth, economic development and the improvement in life safety. This economic development would not be possible without the financial and political support of the US government to maintain the operation of the GPS system. Therefore it is important to have knowledge about the intentions of the US government how system GPS will be developed in the future. Decisions taken in the last 3 months are the subject of this article.

  7. New Directions in the NOAO Observing Proposal System

    Science.gov (United States)

    Gasson, David; Bell, Dave

    For the past eight years NOAO has been refining its on-line observing proposal system. Virtually all related processes are now handled electronically. Members of the astronomical community can submit proposals through email, web form, or via the Gemini Phase I Tool. NOAO staff can use the system to do administrative tasks, scheduling, and compilation of various statistics. In addition, all information relevant to the TAC process is made available on-line, including the proposals themselves (in HTML, PDF and PostScript) and technical comments. Grades and TAC comments are entered and edited through web forms, and can be sorted and filtered according to specified criteria. Current developments include a move away from proprietary solutions, toward open standards such as SQL (in the form of the MySQL relational database system), Perl, PHP and XML.

  8. Classical stability of direct products of spheres in gravitational systems

    International Nuclear Information System (INIS)

    Yasuda, O.

    1984-01-01

    Classical stability of Einstein spaces Ssup(d1) x x x x x Ssup(dn) (dsub(j) >= 2) against all fluctuations is investigated in euclidean gravity with a cosmological constant. It is shown that Ssup(d) is classically stable, while Ssup(d1) x x x x x Ssup(dn) (n >= 2) is classically unstable. As a generalization of this analysis it is proved that a compact Einstein space B 1 x x x x x Bsub(n) (n >= 2) which is a direct product of each Einstein space is classically unstable. Non-Einstein spaces M 2 x S 4 (M 2 x S 2 x S 2 ) are also considered in six-dimensional Einstein-Maxwell theory and are shown to be classically stable (unstable). (orig.)

  9. Passive-solar directional-radiating cooling system

    Science.gov (United States)

    Hull, J.R.; Schertz, W.W.

    1985-06-27

    A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.

  10. Stokes Space in Direct-Detection Data Transmission Systems

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel; Lu, Xiaofeng; Zibar, Darko

    2015-01-01

    Stokes-based processing permits complete and phase-insensitive characterization of the field’s SOP, readily unlocking polarization diversity in transmission systems where DD is desired. We present an overview on Stokes notions and most recent achievements in this context.......Stokes-based processing permits complete and phase-insensitive characterization of the field’s SOP, readily unlocking polarization diversity in transmission systems where DD is desired. We present an overview on Stokes notions and most recent achievements in this context....

  11. Antidepressants and Weight Gain

    Science.gov (United States)

    ... 2015;37:46. Blumenthal SR, et al. An electronic health records study of long-term weight gain following antidepressant ... your agreement to the Terms and Conditions and Privacy Policy linked below. Terms and Conditions Privacy Policy ...

  12. Weight gain - unintentional

    Science.gov (United States)

    ... diabetes Hormone changes or medical problems can also cause unintentional weight gain. This may be due to: Cushing syndrome Underactive thyroid, or low thyroid (hypothyroidism) Polycystic ovary syndrome Menopause Pregnancy Bloating, or swelling ...

  13. Mathematical Model for Direct Evaporative Space Cooling Systems ...

    African Journals Online (AJOL)

    This paper deals with the development of a simple mathematical model for experimental validation of the performance of a small evaporative cooling system in a tropical climate. It also presents the coefficient of convective heat transfer of wide range of temperatures based on existing model. Extensive experiments have ...

  14. Steps towards the universal direct current distribution system

    NARCIS (Netherlands)

    Mackay, L.J.

    2018-01-01

    The traditional ac power system is challenged by emerging distributed renewable energy sources and an increase in installed load capacity, e.g., electric vehicles. Most of these new resources use inherently dc as do more and more appliances. This poses the question, if they should still be connected

  15. Direct nitrous oxide emissions in Mediterranean climate cropping systems

    NARCIS (Netherlands)

    Cayuela, Maria L.; Aguilera, Eduardo; Sanz-Cobena, Alberto; Adams, Dean C.; Abalos Rodriguez, Diego; Barton, Louise; Ryals, Rebecca; Silver, Whendee L.; Alfaro, Marta A.; Pappa, Valentini A.; Bouwman, Lex; Lassaletta, Luis

    2017-01-01

    Many recent reviews and meta-analyses of N2O emissions do not include data from Mediterranean studies. In this paper we present a meta-analysis of the N2O emissions from Mediterranean cropping systems, and propose a more robust and reliable regional emission factor (EF) for

  16. CRISPR technologies for bacterial systems: Current achievements and future directions

    DEFF Research Database (Denmark)

    Choi, Kyeong Rok; Lee, Sang Yup

    2016-01-01

    Throughout the decades of its history, the advances in bacteria-based bio-industries have coincided with great leaps in strain engineering technologies. Recently unveiled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems are now revolution......Throughout the decades of its history, the advances in bacteria-based bio-industries have coincided with great leaps in strain engineering technologies. Recently unveiled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems are now...... revolutionizing biotechnology as well as biology. Diverse technologies have been derived from CRISPR/Cas systems in bacteria, yet the applications unfortunately have not been actively employed in bacteria as extensively as in eukaryotic organisms. A recent trend of engineering less explored strains in industrial...... microbiology-metabolic engineering, synthetic biology, and other related disciplines-is demanding facile yet robust tools, and various CRISPR technologies have potential to cater to the demands. Here, we briefly review the science in CRISPR/Cas systems and the milestone inventions that enabled numerous CRISPR...

  17. Method of operating a direct dme fuel cell system

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a method of operating a fuel cell system comprising one or more fuel cells with a proton exchange membrane, wherein the membrane is composed of a polymeric material comprising acid-doped polybenzimidazole (PBI). The method comprises adjusting the operating...

  18. CRISPR technologies for bacterial systems: Current achievements and future directions.

    Science.gov (United States)

    Choi, Kyeong Rok; Lee, Sang Yup

    2016-11-15

    Throughout the decades of its history, the advances in bacteria-based bio-industries have coincided with great leaps in strain engineering technologies. Recently unveiled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems are now revolutionizing biotechnology as well as biology. Diverse technologies have been derived from CRISPR/Cas systems in bacteria, yet the applications unfortunately have not been actively employed in bacteria as extensively as in eukaryotic organisms. A recent trend of engineering less explored strains in industrial microbiology-metabolic engineering, synthetic biology, and other related disciplines-is demanding facile yet robust tools, and various CRISPR technologies have potential to cater to the demands. Here, we briefly review the science in CRISPR/Cas systems and the milestone inventions that enabled numerous CRISPR technologies. Next, we describe CRISPR/Cas-derived technologies for bacterial strain development, including genome editing and gene expression regulation applications. Then, other CRISPR technologies possessing great potential for industrial applications are described, including typing and tracking of bacterial strains, virome identification, vaccination of bacteria, and advanced antimicrobial approaches. For each application, we note our suggestions for additional improvements as well. In the same context, replication of CRISPR/Cas-based chromosome imaging technologies developed originally in eukaryotic systems is introduced with its potential impact on studying bacterial chromosomal dynamics. Also, the current patent status of CRISPR technologies is reviewed. Finally, we provide some insights to the future of CRISPR technologies for bacterial systems by proposing complementary techniques to be developed for the use of CRISPR technologies in even wider range of applications. Copyright © 2016. Published by Elsevier Inc.

  19. Directions of improving information system of insurance company

    Science.gov (United States)

    Kaigorodova, G. N.; Mustafina, A. A.; Alyakina, D. P.

    2018-05-01

    The article presents a study of the information technologies impact on the insurance industry development. At present, any business, especially business in the field of financial intermediation, can count on maintaining its positions only as a technology company. For the insurance business it is now especially important. Other segments of the financial market - the stock and credit market - are actively developing and applying IT-technologies. The insurance business at present is getting opportunities for a technological breakthrough. There is a growing demand for traditional insurance products - property insurance, motor insurance, health insurance. There is a rapidly growing demand for life insurance and insurance against cyber risks. To implement insurance protection in new conditions, the insurance company should actively use information systems. The article presents a possible variant of systematization of the insurer's business processes within the information system of the insurance company.

  20. Computer Directed Training System (CDTS), User’s Manual

    Science.gov (United States)

    1983-07-01

    lessons, together with an estimate of the time required for completion. a. BSCOl0. This lesson in BASIC ( Beginners All Purpose Symbolic Instruction Code...A2-8 FIGURESj Figure A2-1. Training Systems Manager and Training Monitors Responsibility Flowchart ...training at the site. Therefore, the TSM must be knowledgeable in the various tasks required. Figure A2-1 illustrates the position in the flowchart . These

  1. Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Turgut Gur

    2010-04-30

    This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

  2. Terrestrial Background Reduction in RPM Systems by Direct Internal Shielding

    International Nuclear Information System (INIS)

    Robinson, Sean M.; Ashbaker, Eric D.; Schweppe, John E.

    2008-01-01

    Gamma-ray detection systems that are close to the earth or other sources of background radiation often require shielding, especially when trying to detect a relatively weak source. One particular case of interest that we address in this paper is that encountered by the Radiation Portal Monitors (RPMs) systems placed at border-crossing Ports of Entry (POE). These RPM systems are used to screen for illicit radiological materials, and they are often placed in situations where terrestrial background is large. In such environments, it is desirable to consider simple physical modifications that could be implemented to reduce the effects from background radiation without affecting the flow of traffic and the normal operation of the portal. Simple modifications include adding additional shielding to the environment, either inside or outside the apparatus. Previous work (2) has shown the utility of some of these shielding configurations for increasing the Signal to Noise Ratio (SNR) of gross-counting RPMs. Because the total cost for purchasing and installing RPM systems can be quite expensive, in the range of hundreds of thousands of dollars for each cargo-screening installation, these shielding variations may offer increases in detection capability for relatively small cost. Several modifications are considered here in regard to their real-world applicability, and are meant to give a general idea of the effectiveness of the schemes used to reduce background for both gross-counting and spectroscopic detectors. These scenarios are modeled via the Monte-Carlo N-Particle (MCNP) code package (1) for ease of altering shielding configurations, as well as enacting unusual scenarios prior to prototyping in the field. The objective of this paper is to provide results representative of real modifications that could enhance the sensitivity of this, as well as the next generation of radiation detectors. The models used in this work were designed to provide the most general results for

  3. The MDSplus data acquisition system, current status and future directions

    International Nuclear Information System (INIS)

    Stillerman, J.; Fredian, T.W.

    1999-01-01

    The MDSplus data acquisition system was developed in collaboration with the ZTH group at Los Alamos National Laboratory and the RFX group at CNR in Padua, Italy and is currently in use at MIT, RFX in Padua, and TCV at EPFL in Lausanne. MDSplus is based on a hierarchical experiment description which completely describes the data acquisition and analysis tasks and contains the results from these operations. It also includes a set of X/motif based tools for data acquisition and display, as well as diagnostic configuration and management. These tools were designed to operate in a distributed, client/server environment with multiple concurrent readers and writers to the data store. An interface to a relational database is provided for storage and management of processed data. A commercially available package called IDL is used as the primary data analysis and visualization tool. The current projects include a new interface to the electronic logbook, tools for remote collaborators and WWW access, and a port of the system to UNIX and Windows-NT/95. (orig.)

  4. Bidirectional communication using delay coupled chaotic directly ...

    Indian Academy of Sciences (India)

    Corresponding author. ... 30 September 2009. Abstract. Chaotic synchronization of two directly modulated semiconductor lasers with ... For InGaAsP lasers used in optical communication systems, the nonlinear gain re- duction is very strong and its ...

  5. Changing HIV treatment eligibility under health system constraints in sub-Saharan Africa: investment needs, population health gains, and cost-effectiveness.

    Science.gov (United States)

    Hontelez, Jan A C; Chang, Angela Y; Ogbuoji, Osondu; de Vlas, Sake J; Bärnighausen, Till; Atun, Rifat

    2016-09-24

    We estimated the investment needs, population health gains, and cost-effectiveness of different policy options for scaling-up prevention and treatment of HIV in the 10 countries that currently comprise 80% of all people living with HIV in sub-Saharan Africa (Ethiopia, Kenya, Malawi, Mozambique, Nigeria, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe). We adapted the established STDSIM model to capture the health system dynamics: demand-side and supply-side constraints in the delivery of antiretroviral treatment (ART). We compared different scenarios of supply-side (i.e. health system capacity) and demand-side (i.e. health seeking behavior) constraints, and determined the impact of changing guidelines to ART eligibility at any CD4 cell count within these constraints. Continuing current scale-up would require US$178 billion by 2050. Changing guidelines to ART at any CD4 cell count is cost-effective under all constraints tested in the model, especially in demand-side constrained health systems because earlier initiation prevents loss-to-follow-up of patients not yet eligible. Changing guidelines under current demand-side constraints would avert 1.8 million infections at US$208 per life-year saved. Treatment eligibility at any CD4 cell count would be cost-effective, even under health system constraints. Excessive loss-to-follow-up and mortality in patients not eligible for treatment can be avoided by changing guidelines in demand-side constrained systems. The financial obligation for sustaining the AIDS response in sub-Saharan Africa over the next 35 years is substantial and requires strong, long-term commitment of policy-makers and donors to continue to allocate substantial parts of their budgets.

  6. High voltage direct current transmission converters, systems and DC grids

    CERN Document Server

    Jovcic, Dragan

    2015-01-01

    This comprehensive reference guides the reader through all HVDC technologies, including LCC (Line Commutated Converter), 2-level VSC and VSC HVDC based on modular multilevel converters (MMC) for an in-depth understanding of converters, system level design, operating principles and modeling. Written in a tutorial style, the book also describes the key principles of design, control, protection and operation of DC transmission grids, which will be substantially different from the practice with AC transmission grids. The first dedicated reference to the latest HVDC technologies and DC grid developments; this is an essential resource for graduate students and researchers as well as engineers and professionals working on the design, modeling and operation of DC grids and HVDC.

  7. Unidirectional high gain brake stop

    Science.gov (United States)

    Lang, David J. (Inventor)

    1987-01-01

    This invention relates to a unidirectional high gain brake arrangement that includes in combination a shaft mounted for rotation within a housing. The shaft is rotatable in either direction. A brake is selectively releasably coupled to the housing and to the shaft. The brake has a first member. An intermittent motion device is respectively coupled through the first member to the housing and through a one-way clutch to the shaft. The brake also has a second member that is mechanically coupled to the first brake member and to the housing. The intermittent motion device causes the brake to be activated by movement imparted to the first brake member after a preset number of revolutions of the shaft in one direction. The brake is released by rotation of the shaft in an opposite direction whereby torque transmitted through the one-way clutch to the first brake member is removed.

  8. Design and Operation of an Electrochemical Methanol Concentration Sensor for Direct Methanol Fuel Cell Systems

    Science.gov (United States)

    Narayanan, S. R.; Valdez, T. I.; Chun, W.

    2000-01-01

    The development of a 150-Watt packaged power source based on liquid feed direct methanol fuel cells is being pursued currently at the Jet propulsion Laboratory for defense applications. In our studies we find that the concentration of methanol in the fuel circulation loop affects the electrical performance and efficiency the direct methanol fuel cell systems significantly. The practical operation of direct methanol fuel cell systems, therefore, requires accurate monitoring and control of methanol concentration. The present paper reports on the principle and demonstration of an in-house developed electrochemical sensor suitable for direct methanol fuel cell systems.

  9. Receiver gain function: the actual NMR receiver gain

    OpenAIRE

    Mo, Huaping; Harwood, John S.; Raftery, Daniel

    2010-01-01

    The observed NMR signal size depends on the receiver gain parameter. We propose a receiver gain function to characterize how much the raw FID is amplified by the receiver as a function of the receiver gain setting. Although the receiver is linear for a fixed gain setting, the actual gain of the receiver may differ from what the gain setting suggests. Nevertheless, for a given receiver, we demonstrate that the receiver gain function can be calibrated. Such a calibration enables accurate compar...

  10. Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle

    Science.gov (United States)

    Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

    2013-12-17

    A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

  11. Turbine Engine Clearance Control Systems: Current Practices and Future Directions

    Science.gov (United States)

    Lattime, Scott B.; Steinetz, Bruce M.

    2002-01-01

    Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

  12. Directional radiation pattern in structural-acoustic coupled system

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-07-01

    In this paper we demonstrate the possibility of designing a radiator using structural-acoustic interaction by predicting the pressure distribution and radiation pattern of a structural-acoustic coupling system that is composed by a wall and two spaces. If a wall separates spaces, then the wall's role in transporting the acoustic characteristics of the spaces is important. The spaces can be categorized as bounded finite space and unbounded infinite space. The wall considered in this study composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. This rather hypothetical circumstance is selected to study the general coupling problem between the finite and infinite acoustic domains. We developed an equation that predicts the energy distribution and energy flow in the two spaces separated by a wall, and its computational examples are presented. Three typical radiation patterns that include steered, focused, and omnidirected are presented. A designed radiation pattern is also presented by using the optimal design algorithm.

  13. Optomechanical transistor with mechanical gain

    Science.gov (United States)

    Zhang, X. Z.; Tian, Lin; Li, Yong

    2018-04-01

    We study an optomechanical transistor, where an input field can be transferred and amplified unidirectionally in a cyclic three-mode optomechanical system. In this system, the mechanical resonator is coupled simultaneously to two cavity modes. We show that it only requires a finite mechanical gain to achieve the nonreciprocal amplification. Here the nonreciprocity is caused by the phase difference between the linearized optomechanical couplings that breaks the time-reversal symmetry of this system. The amplification arises from the mechanical gain, which provides an effective phonon bath that pumps the mechanical mode coherently. This effect is analogous to the stimulated emission of atoms, where the probe field can be amplified when its frequency is in resonance with that of the anti-Stokes transition. We show that by choosing optimal parameters, this optomechanical transistor can reach perfect unidirectionality accompanied with strong amplification. In addition, the presence of the mechanical gain can result in ultralong delay in the phase of the probe field, which provides an alternative to controlling light transport in optomechanical systems.

  14. Experimental Comparison of Gains in Achievable Information Rates from Probabilistic Shaping and Digital Backpropagation for DP-256QAM/1024QAM WDM Systems

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Yankov, Metodi Plamenov; Da Ros, Francesco

    2016-01-01

    Gains in achievable information rates from probabilistic shaping and digital backpropagation are compared for WDM transmission of 5 × 10 GBd DP-256QAM/1024QAM up to 1700 km of reach. The combination of both techniques its shown to provide gains of up to ∼0.5 bits/QAM symbol...

  15. Analysis of Direct Samples of Early Solar System Aqueous Fluids

    Science.gov (United States)

    Zolensky, Michael E.; Bodnar, R J.; Fedele, L.; Yurimoto,H.; Itoh, S.; Fries, M.; Steele, A.

    2012-01-01

    Over the past three decades we have become increasingly aware of the fundamental importance of water, and aqueous alteration, on primitive solar-system bodies. Some carbonaceous and ordinary chondrites have been altered by interactions with liquid water within the first 10 million years after formation of their parent asteroids. Millimeter to centimeter-sized aggregates of purple halite containing aqueous fluid inclusions were found in the matrix of two freshly-fallen brecciated H chondrite falls, Monahans (1998, hereafter simply "Monahans") (H5) and Zag (H3-6) (Zolensky et al., 1999; Whitby et al., 2000; Bogard et al., 2001) In order to understand origin and evolution of the aqueous fluids inside these inclusions we much measure the actual fluid composition, and also learn the O and H isotopic composition of the water. It has taken a decade for laboratory analytical techniques to catch up to these particular nanomole-sized aqueous samples. We have recently been successful in (1) measuring the isotopic composition of H and O in the water in a few fluid inclusions from the Zag and Monahans halite, (2) mineralogical characterization of the solid mineral phases associated with the aqueous fluids within the halite, and (3) the first minor element analyses of the fluid itself. A Cameca ims-1270 equipped with a cryo-sample-stage of Hokkaido University was specially prepared for the O and H isotopic measurements. The cryo-sample-stage (Techno. I. S. Corp.) was cooled down to c.a. -190 C using liquid nitrogen at which the aqueous fluid in inclusions was frozen. We excavated the salt crystal surfaces to expose the frozen fluids using a 15 keV Cs+ beam and measured negative secondary ions. The secondary ions from deep craters of approximately 10 m in depth emitted stably but the intensities changed gradually during measurement cycles because of shifting states of charge compensation, resulting in rather poor reproducibility of multiple measurements of standard fluid

  16. Practical considerations for a second-order directional hearing aid microphone system

    Science.gov (United States)

    Thompson, Stephen C.

    2003-04-01

    First-order directional microphone systems for hearing aids have been available for several years. Such a system uses two microphones and has a theoretical maximum free-field directivity index (DI) of 6.0 dB. A second-order microphone system using three microphones could provide a theoretical increase in free-field DI to 9.5 dB. These theoretical maximum DI values assume that the microphones have exactly matched sensitivities at all frequencies of interest. In practice, the individual microphones in the hearing aid always have slightly different sensitivities. For the small microphone separation necessary to fit in a hearing aid, these sensitivity matching errors degrade the directivity from the theoretical values, especially at low frequencies. This paper shows that, for first-order systems the directivity degradation due to sensitivity errors is relatively small. However, for second-order systems with practical microphone sensitivity matching specifications, the directivity degradation below 1 kHz is not tolerable. A hybrid order directive system is proposed that uses first-order processing at low frequencies and second-order directive processing at higher frequencies. This hybrid system is suggested as an alternative that could provide improved directivity index in the frequency regions that are important to speech intelligibility.

  17. Materials directed to implants for repairing Central Nervous System

    Directory of Open Access Journals (Sweden)

    Canillas, M.

    2014-12-01

    Full Text Available Central Nervous System (CNS can be damaged by a wide range of injuries and disorders which entail permanent disability in some cases. Moreover, CNS repairing process presents some complications. The natural repair mechanism, which consists on the glial scar formation, is triggered by the inflammatory process. Molecules delivered during these processes, inflammation and glial scar formation as well as oxygen and glucose deficiencies due to the injury, create an inhibitory environment for axon regeneration and remyelination which is known as “secondary injury”. Biomaterials are taking up an even more important role in repairing CNS. Physicochemical properties of some ceramic materials have inspired different applications to repair CNS as substrates, electrodes or molecule vehicles. Based on their biocompatibility, capability to neutralize reactive species involved in the inflammatory processes and their versatile processing to obtain scaffolds with different shapes and sizes, ceramics are a succulent offer in nervous tissue engineering. Furthermore, their possibilities have been increased with polymeric-ceramics composites development, which have given rise to new interesting horizon.Existen diferentes tipos de lesiones o desordenes del Sistema Nervioso Central (SNC que pueden provocar graves secuelas e incluso en algunos casos una discapacidad permanente. Además, el proceso de reparación del SNC tiene algunas complicaciones. El mecanismo natural de reacción a una lesión, el cual consiste en la formación de una cicatriz glial, es desencadenado por un proceso inflamatorio. Las moléculas liberadas durante estos procesos, la inflamación y formación de la cicatriz glial, así como la deficiencia en oxígeno y glucosa debidos a la lesión, crean un ambiente que inhibe la regeneración axonal creando la llamada “lesión secundaria”. Los biomateriales están adquiriendo un papel cada vez más importante en la reparación de SNC. Las

  18. Direct Current as an Integrating Platform for ZNE Buildings with EVs and Storage: DC Direct Systems – A Bridge to a Low Carbon Future?

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Karl [California Inst. for Energy and the Environment, Berkeley, CA (United States); Vossos, Vagelis [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kloss, Margarita [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Robinson, Gerald [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Rich [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-09-01

    Cost effective zero net energy (ZNE) schemes exist for many types of residential and commercial buildings. Yet, today’s alternating current (AC) based ZNE designs may be as much as 10% to 20% less efficient, more costly, and more complicated than a design based on direct current (DC) technologies. An increasing number of research organizations and manufacturers are just starting the process of developing products and conducting research and development (R&D) efforts. These early R&D efforts indicate that the use of DC technologies may deliver many energy and non-energy benefits relative to AC-based typologies. DC ZNE schemes may provide for an ideal integrating platform for natively DC-based onsite generation, storage, electric vehicle (EV) charging and end-use loads. Emerging empirical data suggest that DC end-use appliances are more efficient, simpler, more durable, and lower cost. DC technologies appear to provide ratepayers a lower cost pathway to achieve resilient ZNE buildings, and simultaneously yield a plethora of benefits. This paper draws from the current research effort entitled "Direct Current as an Integrating and Enabling Platform," co-led by the Lawrence Berkeley National Laboratory (LBNL), the California Institute for Energy and the Environment (CIEE), the Electric Power Research Institute (EPRI) and funded under the California Energy Commission’s Energy Program Investment Charge (CEC EPIC). The first phase of this EPIC research is focused on assembling and summarizing known global performance information on DC and DC-AC hybrid end-use appliances and power systems. This paper summarizes the information and insights gained from this research effort.

  19. Directions for reactor target design based on the US heavy ion fusion systems assessment

    International Nuclear Information System (INIS)

    Wilson, D.C.; Dudziak, D.; Magelssen, G.; Zuckerman, D.; Dreimeyer, D.

    1986-01-01

    We studied areas of major uncertainty in target design using the cost of electricity as our figure of merit. Net electric power from the plant was fixed at 1000 MW to eliminate large effects due to economies of scale. The system is relatively insensitive to target gain. Factors of three changes in gain cause only 8 to 12% changes in electricity cost. An increase in the peak power needed to drive targets poses only a small cost risk, but requires many more beamlets be transported to the target. A shortening of the required ion range causes both cost and beamlet difficulties. A factor of 4 decrease in the required range at a fixed driver energy increases electricity cost by 44% and raises the number of beamlets to 240. Finally, the heavy ion fusion system can accommodate large increases in target costs. To address the major uncertainties, target design should concentrate on the understanding requirements for ion range and peak driver power

  20. Analysis of Bi-directional Effects on the Response of a Seismic Base Isolation System

    International Nuclear Information System (INIS)

    Park, Hyung-Kui; Kim, Jung-Han; Kim, Min Kyu; Choi, In-Kil

    2014-01-01

    The floor response spectrum depends on the height of the floor of the structure. Also FRS depends on the characteristics of the seismic base isolation system such as the natural frequency, damping ratio. In the previous study, the floor response spectrum of the base isolated structure was calculated for each axis without considering bi-directional effect. However, the shear behavior of the seismic base isolation system of two horizontal directions are correlated each other by the bi-directional effects. If the shear behavior of the seismic isolation system changes, it can influence the floor response spectrum and displacement response of isolators. In this study, the analysis of a bi-directional effect on the floor response spectrum was performed. In this study, the response of the seismic base isolation system based on the bi-directional effects was analyzed. By analyzing the time history result, while there is no alteration in the maximum shear force of seismic base isolation system, it is confirmed that the shear force is generally more decreased in a one-directional that in a two-directional in most parts. Due to the overall decreased shear force, the floor response spectrum is more reduced in a two-directional than in a one-directional

  1. Photomultiplier gain stabilisation

    International Nuclear Information System (INIS)

    Le Baud, P.; Sautiez, B.

    1958-07-01

    By the control and adjustment of magnetic deflection applied to the electron beam of a photomultiplier it has proved possible to flatten the gain curve, forming plateaux at levels dependent upon the voltage at intake. It should be possible to add this simple device to most photomultipliers on the market today. (author) [fr

  2. Systems Analysis of Human Visuo-Myoelectric Control Facilitated by Anodal Transcranial Direct Current Stimulation in Healthy Humans

    Directory of Open Access Journals (Sweden)

    Vinh Kha

    2018-04-01

    Full Text Available Induction of neuroplasticity by transcranial direct current stimulation (tDCS applied to the primary motor cortex facilitates motor learning of the upper extremities in healthy humans. The impact of tDCS on lower limb functions has not been studied extensively so far. In this study, we applied a system identification approach to investigate the impact of anodal transcranial direct current stimulation of the leg area of the motor cortex via the human visuo-myoelectric controller. The visuo-myoelectric reaching task (VMT involves ballistic muscle contraction after a visual cue. We applied a black box approach using a linear ARX (Auto-regressive with eXogenous input model for a visuomotor myoelectric reaching task. We found that a 20th order finite impulse response (FIR model captured the TARGET (single input—CURSOR (single output dynamics during a VMT. The 20th order FIR model was investigated based on gain/phase margin analysis, which showed a significant (p < 0.01 effect of anodal tDCS on the gain margin of the VMT system. Also, response latency and the corticomuscular coherence (CMC time delay were affected (p < 0.05 by anodal tDCS when compared to sham tDCS. Furthermore, gray box simulation results from a Simplified Spinal-Like Controller (SSLC model demonstrated that the input-output function for motor evoked potentials (MEP played an essential role in increasing muscle activation levels and response time improvement post-tDCS when compared to pre-tDCS baseline performance. This computational approach can be used to simulate the behavior of the neuromuscular controller during VMT to elucidate the effects of adjuvant treatment with tDCS.

  3. Direct heuristic dynamic programming for damping oscillations in a large power system.

    Science.gov (United States)

    Lu, Chao; Si, Jennie; Xie, Xiaorong

    2008-08-01

    This paper applies a neural-network-based approximate dynamic programming method, namely, the direct heuristic dynamic programming (direct HDP), to a large power system stability control problem. The direct HDP is a learning- and approximation-based approach to addressing nonlinear coordinated control under uncertainty. One of the major design parameters, the controller learning objective function, is formulated to directly account for network-wide low-frequency oscillation with the presence of nonlinearity, uncertainty, and coupling effect among system components. Results include a novel learning control structure based on the direct HDP with applications to two power system problems. The first case involves static var compensator supplementary damping control, which is used to provide a comprehensive evaluation of the learning control performance. The second case aims at addressing a difficult complex system challenge by providing a new solution to a large interconnected power network oscillation damping control problem that frequently occurs in the China Southern Power Grid.

  4. Frequency Properties Research of Elevator Drive System with Direct Torque Control-Pulse with Modulation

    Directory of Open Access Journals (Sweden)

    A. S. Koval

    2008-01-01

    Full Text Available In the article problems of frequency properties research for electric drive system with direct torque control and pulse width modulator are described. The mathematical description of elevator is present. Simplified mathematical description of direct torque control - pulse width modulator electric drive system is shown. Transfer functions for torque and speed loops are determined. Logarithmic frequency characteristics are computed. Damping properties of elevator drive system are estimated.

  5. Directional x-ray dark-field imaging of strongly ordered systems

    Science.gov (United States)

    Jensen, Torben Haugaard; Bech, Martin; Zanette, Irene; Weitkamp, Timm; David, Christian; Deyhle, Hans; Rutishauser, Simon; Reznikova, Elena; Mohr, Jürgen; Feidenhans'L, Robert; Pfeiffer, Franz

    2010-12-01

    Recently a novel grating based x-ray imaging approach called directional x-ray dark-field imaging was introduced. Directional x-ray dark-field imaging yields information about the local texture of structures smaller than the pixel size of the imaging system. In this work we extend the theoretical description and data processing schemes for directional dark-field imaging to strongly scattering systems, which could not be described previously. We develop a simple scattering model to account for these recent observations and subsequently demonstrate the model using experimental data. The experimental data includes directional dark-field images of polypropylene fibers and a human tooth slice.

  6. FIA-automated system used to electrochemically measure nitrite and its interfering chemicals through a 1-2 DAB / Au electrode: gain of sensitivity at upper potentials

    Science.gov (United States)

    Almeida, F. L.; dos Santos Filho, S. G.; Fontes, M. B. A.

    2013-03-01

    The measurement of nitrite and its interfering-chemicals (paracetamol, ascorbic acid and uric acid) was performed employing a Flow-injection Analysis (FIA) system, which was automated using solenoid valves and air-pump. It is very important to quantify nitrite from river water, food and biologic fluids due to its antibacterial capacity in moderated concentrations, or its toxicity for human health even at low concentrations (> 20 μmol L-1 in blood fluids). Electrodes of the electrochemical planar sensor were defined by silk-screen technology. The measuring electrode was made from gold paste covered with 1-2 cis Diaminobenzene (DAB), which allowed good selectivity, linearity, repeatability, stability and optimized gain of sensitivity at 0.5 VAg/AgCl Nafion®117 (6.93 μA mol-1 L mm-2) compared to 0.3 VAg/AgCl Nafion® 117. The reference electrode was obtained from silver/palladium paste modified with chloride and covered with Nafion® 117. The auxiliary electrode was made from platinum paste. It was noteworthy that nitrite response adds to the response of the studied interfering-chemicals and it is predominant for concentrations lower than 175 μmol L-1.

  7. SU-E-I-11: Cascaded Linear System Model for Columnar CsI Flat Panel Imagers with Depth Dependent Gain and Blur

    International Nuclear Information System (INIS)

    Peng, B; Lubinsky, A; Zheng, H; Zhao, W; Teymurazyan, A

    2014-01-01

    Purpose: To implement a depth dependent gain and blur cascaded linear system model (CLSM) for optimizing columnar structured CsI indirect conversion flat panel imager (FPI) for advanced imaging applications. Methods: For experimental validation, depth dependent escape efficiency, e(z), was extracted from PHS measurement of different CsI scintillators (thickness, substrate and light output). The inherent MTF and DQE of CsI was measured using high resolution CMOS sensor. For CLSM, e(z) and the depth dependent MTF(f,z), were estimated using Monte Carlo simulation (Geant4) of optical photon transport through columnar CsI. Previous work showed that Monte Carlo simulation for CsI was hindered by the non-ideality of its columnar structure. In the present work we allowed variation in columnar width with depth, and assumed diffusive reflective backing and columns. Monte Carlo simulation was performed using an optical point source placed at different depth of the CsI layer, from which MTF(z,f) and e(z) were computed. The resulting e(z) with excellent matching with experimental measurements were then applied to the CLSM, Monte Carlo simulation was repeated until the modeled MTF, DQE(f) also match experimental measurement. Results: For a 150 micron FOS HL type CsI, e(z) varies between 0.56 to 0.45, and the MTF at 14 cycles/mm varies between 62.1% to 3.9%, from the front to the back of the scintillator. The overall MTF and DQE(f) at all frequencies are in excellent agreement with experimental measurements at all frequencies. Conclusion: We have developed a CLSM for columnar CsI scintillators with depth dependent gain and MTF, which were estimated from Monte Carlo simulation with novel optical simulation settings. Preliminary results showed excellent agreement between simulation results and experimental measurements. Future work is aimed at extending this approach to optimize CsI screen optic design and sensor structure for achieving higher DQE(f) in cone-beam CT, which uses

  8. Gain Shift Corrections at Chi-Nu

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Tristan Brooks [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics and Applied Physics; Devlin, Matthew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-30

    Ambient conditions have the potential to cause changes in liquid scintillator detector gain that vary with time and temperature. These gain shifts can lead to poor resolution in both energy as well as pulse shape discrimination. In order to correct for these shifts in the Chi-Nu high energy array, a laser system has been developed for calibration of the pulse height signals.

  9. Learn and gain

    CERN Document Server

    Al-Alami, Suhair Eyad Jamal

    2013-01-01

    Initiating the slogan ""love it, live it"", Learn and Gain includes eight short stories, chosen to illustrate various modes of narration, as well as to provoke reflection and discussion on a range of issues. All texts utilized here illustrate how great writers can, with their insight and gift for words, help us to see the world we live in, in new probing and exciting ways. What characterises the book, the author believes, is the integration of the skills of literary competence, communicative c...

  10. 78 FR 28005 - System Energy Resources, Inc.; Grand Gulf Nuclear Station; Order Approving Direct and Indirect...

    Science.gov (United States)

    2013-05-13

    ... direct transfer of Grand Gulf ESP Site, to a new limited liability company, System Energy Resource, LLC..., LLC, a Delaware limited liability company, will be created, which will be the direct parent company of... Operations, Inc. (EOI), requested on behalf of itself, SERI, and their parent companies (together, the...

  11. Direct and semi-direct aerosol radiative effect on the Mediterranean climate variability using a coupled regional climate system model

    Science.gov (United States)

    Nabat, Pierre; Somot, Samuel; Mallet, Marc; Sevault, Florence; Chiacchio, Marc; Wild, Martin

    2015-02-01

    A fully coupled regional climate system model (CNRM-RCSM4) has been used over the Mediterranean region to investigate the direct and semi-direct effects of aerosols, but also their role in the radiation-atmosphere-ocean interactions through multi-annual ensemble simulations (2003-2009) with and without aerosols and ocean-atmosphere coupling. Aerosols have been taken into account in CNRM-RCSM4 through realistic interannual monthly AOD climatologies. An evaluation of the model has been achieved, against various observations for meteorological parameters, and has shown the ability of CNRM-RCSM4 to reproduce the main patterns of the Mediterranean climate despite some biases in sea surface temperature (SST), radiation and cloud cover. The results concerning the aerosol radiative effects show a negative surface forcing on average because of the absorption and scattering of the incident radiation. The SW surface direct effect is on average -20.9 Wm-2 over the Mediterranean Sea, -14.7 Wm-2 over Europe and -19.7 Wm-2 over northern Africa. The LW surface direct effect is weaker as only dust aerosols contribute (+4.8 Wm-2 over northern Africa). This direct effect is partly counterbalanced by a positive semi-direct radiative effect over the Mediterranean Sea (+5.7 Wm-2 on average) and Europe (+5.0 Wm-2) due to changes in cloud cover and atmospheric circulation. The total aerosol effect is consequently negative at the surface and responsible for a decrease in land (on average -0.4 °C over Europe, and -0.5 °C over northern Africa) and sea surface temperature (on average -0.5 °C for the Mediterranean SST). In addition, the latent heat loss is shown to be weaker (-11.0 Wm-2) in the presence of aerosols, resulting in a decrease in specific humidity in the lower troposphere, and a reduction in cloud cover and precipitation. Simulations also indicate that dust aerosols warm the troposphere by absorbing solar radiation, and prevent radiation from reaching the surface, thus

  12. Generalized direct Lyapunov method for the analysis of stability and attraction in general time systems

    International Nuclear Information System (INIS)

    Druzhinina, O V; Shestakov, A A

    2002-01-01

    A generalized direct Lyapunov method is put forward for the study of stability and attraction in general time systems of the following types: the classical dynamical system in the sense of Birkhoff, the general system in the sense of Zubov, the general system in the sense of Seibert, the general system with delay, and the general 'input-output' system. For such systems, with the help of generalized Lyapunov functions with respect to two filters, two quasifilters, or two filter bases, necessary and sufficient conditions for stability and attraction are obtained under minimal assumptions about the mathematical structure of the general system

  13. Digital tumor fluoroscopy (DTF)--a new direct imaging system in the therapy planning for brain tumors.

    Science.gov (United States)

    Herbst, M; Fröder, M

    1990-01-01

    Digital Tumor Fluoroscopy is an expanded x-ray video chain optimized to iodine contrast with an extended Gy scale up to 64000 Gy values. Series of pictures are taken before and after injection of contrast medium. With the most recent unit, up to ten images can be taken and stored. The microprogrammable processor allows the subtraction of images recorded at any moment of the examination. Dynamic views of the distribution of contrast medium in the intravasal and extravasal spaces of brain and tumor tissue are gained by the subtraction of stored images. Tumors can be differentiated by studying the storage and drainage behavior of the contrast medium during the period of examination. Meningiomas store contrast medium very intensively during the whole time of investigation, whereas astrocytomas grade 2-3 pick it up less strongly at the beginning and release it within 2 min. Glioblastomas show a massive but delayed accumulation of contrast medium and a decreased flow-off-rate. In comparison with radiography and MR-imaging the most important advantage of Digital Tumor Fluoroscopy is that direct information on tumor localization is gained in relation to the skull-cap. This enables the radiotherapist to mark the treatment field directly on the skull. Therefore it is no longer necessary to calculate the tumor volume from several CT scans for localization. In radiotherapy Digital Tumor Fluoroscopy a unit combined with a simulator can replace CT planning. This would help overcome the disadvantages arising from the lack of a collimating system, and the inaccuracies which result from completely different geometric relationships between a CT unit and a therapy machine.

  14. Consistency of direct integral estimator for partially observed systems of ordinary differential equations

    NARCIS (Netherlands)

    Vujačić, Ivan; Dattner, Itai

    In this paper we use the sieve framework to prove consistency of the ‘direct integral estimator’ of parameters for partially observed systems of ordinary differential equations, which are commonly used for modeling dynamic processes.

  15. A direct probe of dark energy interactions with a solar System laboratory

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a mission concept for direct detection of dark energy interactions with normal matter in a Solar System laboratory. Dark energy is the leading proposal to...

  16. NATIONAL SYSTEM OF CRISIS MANAGEMENT AS A TACTICAL AND STRATEGIC DIRECTION OF THE RUSSIAN ECONOMY

    Directory of Open Access Journals (Sweden)

    I. V. Gladkov

    2014-01-01

    Full Text Available Depending on the origin, nature and extent of the crisis, measures of state intervention and direction must be different. In this regard, it seems appropriate to talk about the need to form a national crisis management system.

  17. Gains from trans-boundary water quality management in linked catchment and coastal socio-ecological systems: a case study for the Minho region

    Science.gov (United States)

    Roebeling, P. C.; Brito, A. G.; Rocha, J.; Alves, H.; Mamede, J.

    2012-04-01

    Worldwide, aquatic and coastal ecosystems are affected by point and diffuse source water pollution originating from rural, urban and industrial land uses in catchments, even though these ecosystems are of vital importance from an environmental and economic perspective. Integrated Catchment and Coastal Zone Management (ICCZM) specifically takes into account this inherent relationship between terrestrial land use, surface and ground water pollution, aquatic and coastal ecosystem state, and associated environmental values. To warrant sustainable regional economic development, we need to balance the marginal costs from terrestrial water pollution abatement and the associated marginal benefits from aquatic and coastal resource appreciation. In doing so, however, we need to differentiate between intra- and trans-boundary catchments because benefactors and beneficiaries from water quality improvement are not one and the same. In trans-boundary catchments, private (national) welfare maximizing rates of water quality improvement differ across nations as benefits from water quality improvement generally accrue to one nation while the costs are paid by multiple nations. While approaches for water quality management in linked catchment and coastal socio-ecological systems are fairly recent though existent, water quality management in trans-boundary catchments poses additional challenges. The objective of this paper is to develop and apply a deterministic optimal control approach that allows us to explore private and social welfare maximizing rates of water pollution abatement in linked catchment and coastal socio-ecological systems. For a case study of the Minho region in the Iberian Peninsula, we estimate nation-specific water pollution abatement cost (based on management practice adoption) and benefit (based on aquatic and coastal environmental values) functions, to determine as well as compare private (national) and social (trans-national) welfare maximizing rates of water

  18. Source coherence impairments in a direct detection direct sequence optical code-division multiple-access system.

    Science.gov (United States)

    Fsaifes, Ihsan; Lepers, Catherine; Lourdiane, Mounia; Gallion, Philippe; Beugin, Vincent; Guignard, Philippe

    2007-02-01

    We demonstrate that direct sequence optical code- division multiple-access (DS-OCDMA) encoders and decoders using sampled fiber Bragg gratings (S-FBGs) behave as multipath interferometers. In that case, chip pulses of the prime sequence codes generated by spreading in time-coherent data pulses can result from multiple reflections in the interferometers that can superimpose within a chip time duration. We show that the autocorrelation function has to be considered as the sum of complex amplitudes of the combined chip as the laser source coherence time is much greater than the integration time of the photodetector. To reduce the sensitivity of the DS-OCDMA system to the coherence time of the laser source, we analyze the use of sparse and nonperiodic quadratic congruence and extended quadratic congruence codes.

  19. Source coherence impairments in a direct detection direct sequence optical code-division multiple-access system

    Science.gov (United States)

    Fsaifes, Ihsan; Lepers, Catherine; Lourdiane, Mounia; Gallion, Philippe; Beugin, Vincent; Guignard, Philippe

    2007-02-01

    We demonstrate that direct sequence optical code- division multiple-access (DS-OCDMA) encoders and decoders using sampled fiber Bragg gratings (S-FBGs) behave as multipath interferometers. In that case, chip pulses of the prime sequence codes generated by spreading in time-coherent data pulses can result from multiple reflections in the interferometers that can superimpose within a chip time duration. We show that the autocorrelation function has to be considered as the sum of complex amplitudes of the combined chip as the laser source coherence time is much greater than the integration time of the photodetector. To reduce the sensitivity of the DS-OCDMA system to the coherence time of the laser source, we analyze the use of sparse and nonperiodic quadratic congruence and extended quadratic congruence codes.

  20. A gain-loss framework based on ensemble flow forecasts to switch the urban drainage-wastewater system management towards energy optimization during dry periods

    Science.gov (United States)

    Courdent, Vianney; Grum, Morten; Munk-Nielsen, Thomas; Mikkelsen, Peter S.

    2017-05-01

    Precipitation is the cause of major perturbation to the flow in urban drainage and wastewater systems. Flow forecasts, generated by coupling rainfall predictions with a hydrologic runoff model, can potentially be used to optimize the operation of integrated urban drainage-wastewater systems (IUDWSs) during both wet and dry weather periods. Numerical weather prediction (NWP) models have significantly improved in recent years, having increased their spatial and temporal resolution. Finer resolution NWP are suitable for urban-catchment-scale applications, providing longer lead time than radar extrapolation. However, forecasts are inevitably uncertain, and fine resolution is especially challenging for NWP. This uncertainty is commonly addressed in meteorology with ensemble prediction systems (EPSs). Handling uncertainty is challenging for decision makers and hence tools are necessary to provide insight on ensemble forecast usage and to support the rationality of decisions (i.e. forecasts are uncertain and therefore errors will be made; decision makers need tools to justify their choices, demonstrating that these choices are beneficial in the long run). This study presents an economic framework to support the decision-making process by providing information on when acting on the forecast is beneficial and how to handle the EPS. The relative economic value (REV) approach associates economic values with the potential outcomes and determines the preferential use of the EPS forecast. The envelope curve of the REV diagram combines the results from each probability forecast to provide the highest relative economic value for a given gain-loss ratio. This approach is traditionally used at larger scales to assess mitigation measures for adverse events (i.e. the actions are taken when events are forecast). The specificity of this study is to optimize the energy consumption in IUDWS during low-flow periods by exploiting the electrical smart grid market (i.e. the actions are taken

  1. Comparing direct and iterative equation solvers in a large structural analysis software system

    Science.gov (United States)

    Poole, E. L.

    1991-01-01

    Two direct Choleski equation solvers and two iterative preconditioned conjugate gradient (PCG) equation solvers used in a large structural analysis software system are described. The two direct solvers are implementations of the Choleski method for variable-band matrix storage and sparse matrix storage. The two iterative PCG solvers include the Jacobi conjugate gradient method and an incomplete Choleski conjugate gradient method. The performance of the direct and iterative solvers is compared by solving several representative structural analysis problems. Some key factors affecting the performance of the iterative solvers relative to the direct solvers are identified.

  2. Predictive Variable Gain Iterative Learning Control for PMSM

    Directory of Open Access Journals (Sweden)

    Huimin Xu

    2015-01-01

    Full Text Available A predictive variable gain strategy in iterative learning control (ILC is introduced. Predictive variable gain iterative learning control is constructed to improve the performance of trajectory tracking. A scheme based on predictive variable gain iterative learning control for eliminating undesirable vibrations of PMSM system is proposed. The basic idea is that undesirable vibrations of PMSM system are eliminated from two aspects of iterative domain and time domain. The predictive method is utilized to determine the learning gain in the ILC algorithm. Compression mapping principle is used to prove the convergence of the algorithm. Simulation results demonstrate that the predictive variable gain is superior to constant gain and other variable gains.

  3. Gains from quota trade

    DEFF Research Database (Denmark)

    Andersen, Jesper Levring; Bogetoft, Peter

    2007-01-01

    We provide a framework for evaluating potential effects of introducing tradable quotas to a sector. The effects depend on the economies of scale and scope of the production technology, and on firms' ability and willingness to learn best practice methods (catching up) and to change their input...... and output composition (mix). To illustrate our approach, data from the Danish fishery are used to calculate the potential gains from introducing individually transferable fishing quotas. Data envelopment analysis is used to model the production technology. We find that pure reallocation is as important...

  4. Gaining Relational Competitive Advantages

    DEFF Research Database (Denmark)

    Hu, Yimei; Zhang, Si; Li, Jizhen

    2015-01-01

    Establishing strategic technological partnerships (STPs) with foreign partners is an increasingly studied topic within the innovation management literature. Partnering firms can jointly create sources of relational competitive advantage. Chinese firms often lack research and development (R......&D) capabilities but are increasingly becoming preferred technological partners for transnational corporations. We investigate an STP between a Scandinavian and a Chinese firm and try to explore how to gain relational competitive advantage by focusing on its two essential stages: relational rent generation...... and appropriation. Based on an explorative case study, we develop a conceptual framework that consists of process, organizational alliance factors, and coordination modes that we propose lead to relational competitive advantage....

  5. Gain control mechanisms in spinal motoneurons

    Directory of Open Access Journals (Sweden)

    Michael David Johnson

    2014-07-01

    Full Text Available Motoneurons provide the only conduit for motor commands to reach muscles. For many years, motoneurons were in fact considered to be little more than passive wires. Systematic studies in the past 25 years however have clearly demonstrated that the intrinsic electrical properties of motoneurons are under strong neuromodulatory control via multiple sources. The discovery of potent neuromodulation from the brainstem and its ability to change the gain of motoneurons shows that the passive view of the motor output stage is no longer tenable. A mechanism for gain control at the motor output stage makes good functional sense considering our capability of generating an enormous range of forces, from very delicate (e.g. putting in a contact lens to highly forceful (emergency reactions. Just as sensory systems need gain control to deal with a wide dynamic range of inputs, so to might motor output need gain control to deal with the wide dynamic range of the normal movement repertoire. Two problems emerge from the potential use of the brainstem monoaminergic projection to motoneurons for gain control. First, the projection is highly diffuse anatomically, so that independent control of the gains of different motor pools is not feasible. In fact, the system is so diffuse that gain for all the motor pools in a limb likely increases in concert. Second, if there is a system that increases gain, probably a system to reduce gain is also needed. In this review, we summarize recent studies that show local inhibitory circuits within the spinal cord, especially reciprocal and recurrent inhibition, have the potential to solve both of these problems as well as constitute another source of gain modulation.

  6. The role and behaviour of the experts and how to expose the experts' value system in order to gain stakeholder confidence

    International Nuclear Information System (INIS)

    Andersson, Kjell

    2006-01-01

    The author discussed the role and behaviour of experts in the context of gaining stakeholder confidence. The author underscored the many reasons to make explicit experts' values. Complex policy issues often involve many challenges, factual issues with uncertainties, values, emotions and vested interests. All of these factors should be exposed to policy makers and the public before decisions are made. Experts may set the agendas too narrowly, there may be mistrust in expertise and authorities, and there may be low awareness in the political system. Excessively narrow framing of the issues can result in frustration and inability to solve important societal problems. It was noted further, that in a democratic society decisions are based not on expert values, but on citizen values. Democracy implies accountability and requires awareness and transparency. Modern society is demanding higher levels of transparency and public participation dialogue and incorporation of public values. The author reviewed some of the models which have been advanced for awareness building with transparency and participation within frameworks of representative democracy. The RISKOM model was discussed, as was the VALDOC model, both of which invoke the practice of 'stretching' - inviting questions to be raised from new angles through challenges from society. Another key element of the RISKOM model is 'intelligence' - understanding future developments and outside forces, as well as studying and planning for the future. Crucial aspects of the VALDOC methodology include the authenticity of the approach itself, its identity in awareness and transparency, fairness in process setting and ensure neutral venues for hearings and transparency arenas. The presentation highlighted some applications of these models in a variety of industries in Sweden. The presentation reviewed a number of arenas in which experts' value systems may be exposed. Within the expert arena, it was

  7. Direct Load Control (DLC) Considering Nodal Interrupted Energy Assessment Rate (NIEAR) in Restructured Power Systems

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Wang, Peng; Goel, Lalit

    2010-01-01

    is used as the bids from the ACL customers, is utilized to determine the direct monetary compensation to the ACL customers. The proposed scheme was investigated for the PoolCo electricity market. The optimal DLC scheme is determined based on the minimum system operating cost which is comprised......A direct load control (DLC) scheme of air conditioning loads (ACL) considering direct monetary compensation to ACL customers for the service interruption caused by the DLC program is proposed in this paper for restructured power systems. The nodal interrupted energy assessment rate (NIEAR), which...... of the system energy cost, the system spinning reserve cost and the compensation cost to the ACL customers. Dynamic programming (DP) was used to obtain the optimal DLC scheme. The IEEE reliability test system (RTS) was studied to illustrate the proposed DLC scheme....

  8. Immune regulation in gut and cord : opportunities for directing the immune system

    NARCIS (Netherlands)

    de Roock, S.

    2012-01-01

    The gut is an important organ for the immune system. Microbes and immune cells interact directly or via epithelial cells. Both TH17 and Treg cells mature in this environment. The composition of the microbiota has an important influence on the immune homeostasis. Influencing the immune system via the

  9. Main Directions in Ensuring Business Continuity for Information and Telecommunication Systems of High Availability

    Directory of Open Access Journals (Sweden)

    Boris Mikhailovich Egorov

    2014-12-01

    Full Text Available Enterprise Continuity Program, Information and Telecommunication System of Bank of Russia The results of the analysis of the main directions to ensure business continuity for the information and telecommunication systems of high availability in relation to expansion of the problems range, their intellectualization and the modern IT implementation are given.

  10. Broken symmetries and directed collective energy transport in spatially extended systems

    DEFF Research Database (Denmark)

    Flach, S.; Zolotaryuk, Yaroslav; Miroshnichenko, A. E.

    2002-01-01

    We study the appearance of directed energy current in homogeneous spatially extended systems coupled to a heat bath in the presence of an external ac field E(t) . The systems are described by nonlinear field equations. By making use of a symmetry analysis, we predict the right choice of E(t) and ...

  11. Mirror System for Collecting Thomson-Scattered Light in a Tangential Direction

    NARCIS (Netherlands)

    Barth, C. J.; Grobben, B. J. J.; Verhaag, G. C. H. M.

    1994-01-01

    We describe an optical system for collecting Thomson-scattering light in the tangential direction of a tokamak. The key part of the optics is a set of mirrors arranged as a Venetian blind. This system makes it possible to look around the corner of the tokamak vessel. Design considerations and test

  12. Direct-drive electromagnetic active suspension system with integrated eddy current damping for automotive applications

    NARCIS (Netherlands)

    Gysen, B.L.J.; Paulides, J.J.H.; Lomonova, E.

    2011-01-01

    A direct-drive electromagnetic active suspension system is considered which consists of a tubular permanent magnet actuator in parallel with a coil spring. This system has the ability of improving the ride comfort while maintaining optimum handling and stability. Since safety is of major concern,

  13. Second-Order Consensus for Multiagent Systems With Directed Topologies and Nonlinear Dynamics

    NARCIS (Netherlands)

    Yu, Wenwu; Chen, Guanrong; Cao, Ming; Kurths, Juergen; Kurths, Jürgen

    This paper considers a second-order consensus problem for multiagent systems with nonlinear dynamics and directed topologies where each agent is governed by both position and velocity consensus terms with a time-varying asymptotic velocity. To describe the system's ability for reaching consensus, a

  14. Optimization Tool for Direct Water Cooling System of High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Blaabjerg, Frede

    2016-01-01

    important issue for thermal design engineers. This paper aims to present a user friendly optimization tool for direct water cooling system of a high power module which enables the cooling system designer to identify the optimized solution depending on customer load profiles and available pump power. CFD...

  15. Fuzzy-Logic-Based Gain-Scheduling Control for State-of-Charge Balance of Distributed Energy Storage Systems for DC Microgrids

    DEFF Research Database (Denmark)

    Aldana, Nelson Leonardo Diaz; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2014-01-01

    -charge or deep-discharge in one of the energy storage units. Primary control in a microgrid is responsible for power sharing among units; and droop control is typically used in this stage. This paper proposes a modular and decentralized gain-scheduling control strategy based on fuzzy logic that ensures balanced...

  16. Changing HIV treatment eligibility under health system constraints in sub-Saharan Africa: Investment needs, population health gains, and cost-effectiveness

    NARCIS (Netherlands)

    J.A.C. Hontelez (Jan); A.Y. Chang (Angela Y.); O. Ogbuoji (Osondu); S.J. de Vlas (Sake); T. Bärnighausen (Till); R. Atun (Rifat)

    2016-01-01

    markdownabstract__Objective:__ We estimated the investment needs, population health gains, and costeffectiveness of different policy options for scaling-up prevention and treatment of HIV in the 10 countries that currently comprise 80% of all people living with HIV in sub- Saharan Africa (Ethiopia,

  17. FEL gain optimisation and spontaneous radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

    1995-12-31

    Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

  18. Extended exergy concept to facilitate designing and optimization of frequency-dependent direct energy conversion systems

    International Nuclear Information System (INIS)

    Wijewardane, S.; Goswami, Yogi

    2014-01-01

    Highlights: • Proved exergy method is not adequate to optimize frequency-dependent energy conversion. • Exergy concept is modified to facilitate the thermoeconomic optimization of photocell. • The exergy of arbitrary radiation is used for a practical purpose. • The utility of the concept is illustrated using pragmatic examples. - Abstract: Providing the radiation within the acceptable (responsive) frequency range(s) is a common method to increase the efficiency of the frequency-dependent energy conversion systems, such as photovoltaic and nano-scale rectenna. Appropriately designed auxiliary items such as spectrally selective thermal emitters, optical filters, and lenses are used for this purpose. However any energy conversion method that utilizes auxiliary components to increase the efficiency of a system has to justify the potential cost incurred by those auxiliary components through the economic gain emerging from the increased system efficiency. Therefore much effort should be devoted to design innovative systems, effectively integrating the auxiliary items and to optimize the system with economic considerations. Exergy is the widely used method to design and optimize conventional energy conversion systems. Although the exergy concept is used to analyze photovoltaic systems, it has not been used effectively to design and optimize such systems. In this manuscript, we present a modified exergy method in order to effectively design and economically optimize frequency-dependent energy conversion systems. Also, we illustrate the utility of this concept using examples of thermophotovoltaic, Photovoltaic/Thermal and concentrated solar photovoltaic

  19. Design Optimization and Site Matching of Direct-Drive Permanent Magnet Wind Generator Systems

    DEFF Research Database (Denmark)

    Li, H.; Chen, Zhe

    2009-01-01

    This paper investigates the possible site matching of the direct-drive wind turbine concepts based on the electromagnetic design optimization of permanent magnet (PM) generator systems. Firstly, the analytical models of a three-phase radial-flux PM generator with a back-to-back power converter...... of the maximum wind energy capture, the rotor diameter and the rated wind speed of a direct-drive wind turbine with the optimum PM generator are determined. The annual energy output (AEO) is also presented using the Weibull density function. Finally, the maximum AEO per cost (AEOPC) of the optimized wind...... are presented. The optimum design models of direct-drive PM wind generation system are developed with an improved genetic algorithm, and a 500-kW direct-drive PM generator for the minimal generator active material cost is compared to demonstrate the effectiveness of the design optimization. Forty-five PM...

  20. Fast digital zooming system using directionally adaptive image interpolation and restoration.

    Science.gov (United States)

    Kang, Wonseok; Jeon, Jaehwan; Yu, Soohwan; Paik, Joonki

    2014-01-01

    This paper presents a fast digital zooming system for mobile consumer cameras using directionally adaptive image interpolation and restoration methods. The proposed interpolation algorithm performs edge refinement along the initially estimated edge orientation using directionally steerable filters. Either the directionally weighted linear or adaptive cubic-spline interpolation filter is then selectively used according to the refined edge orientation for removing jagged artifacts in the slanted edge region. A novel image restoration algorithm is also presented for removing blurring artifacts caused by the linear or cubic-spline interpolation using the directionally adaptive truncated constrained least squares (TCLS) filter. Both proposed steerable filter-based interpolation and the TCLS-based restoration filters have a finite impulse response (FIR) structure for real time processing in an image signal processing (ISP) chain. Experimental results show that the proposed digital zooming system provides high-quality magnified images with FIR filter-based fast computational structure.

  1. Directional sound beam emission from a configurable compact multi-source system

    KAUST Repository

    Zhao, Jiajun

    2018-01-12

    We propose to achieve efficient emission of highly directional sound beams from multiple monopole sources embedded in a subwavelength enclosure. Without the enclosure, the emitted sound fields have an indistinguishable or omnidirectional radiation directivity in far fields. The strong directivity formed in the presence of the enclosure is attributed to interference of sources under degenerate Mie resonances in the enclosure of anisotropic property. Our numerical simulations of sound emission from the sources demonstrate the radiation of a highly directed sound beam of unidirectional or bidirectional patterns, depending on how the sources are configured inside the enclosure. Our scheme, if achieved, can solve the challenging problem of poor directivity of a subwavelength sound system, and can guide beam forming and collimation by miniaturized devices.

  2. Practical Consideration Factors to Design Array Configuration of Direction Finding System for Airborne Signal Intelligence

    Directory of Open Access Journals (Sweden)

    Jong-Hwan Lee

    2018-01-01

    Full Text Available Airborne signal intelligence (SIGINT systems must be capable of locating radio signal sources. Direction finding (DF to support this capability is an important factor. There are some practical considerations to be taken when designing the array configuration of a DF system for airborne SIGINT systems. This paper summarizes the practical factors when designing the array configuration of the DF system for airborne SIGINT. In particular, it focuses on four areas: antenna consideration factors when installing the DF system for airborne SIGINT from a practical point of view, array configuration methods for airborne communications intelligence and electronic intelligence, and a numerical analysis to select the optimum antenna position for airborne SIGINT.

  3. A direct plasma injection system into an RFQ for clean and safe ion implantation

    International Nuclear Information System (INIS)

    Takeuchi, T.; Katayama, T.; Okamura, M.; Yano, K.; Sakumi, A.; Hattori, T.; Hayashizaki, N.; Jameson, R.A.

    2002-01-01

    A new injection system, direct plasma injection system, was tested and its principle was proved successfully. We found that one of advantages of this injection system was efficient consumption of source materials. Large portions of induced ions can be injected into a first stage accelerator. This feature is quite useful for ion implantation applications, because toxic exhaust gas can be eliminated. In order to utilize this system for industrial application, the feasibility of a boron injection scheme using a Nd:YAG laser system was investigated

  4. Hybrid PAPR reduction scheme with Huffman coding and DFT-spread technique for direct-detection optical OFDM systems

    Science.gov (United States)

    Peng, Miao; Chen, Ming; Zhou, Hui; Wan, Qiuzhen; Jiang, LeYong; Yang, Lin; Zheng, Zhiwei; Chen, Lin

    2018-01-01

    High peak-to-average power ratio (PAPR) of the transmit signal is a major drawback in optical orthogonal frequency division multiplexing (OOFDM) system. In this paper, we propose and experimentally demonstrate a novel hybrid scheme, combined the Huffman coding and Discrete Fourier Transmission-Spread (DFT-spread), in order to reduce high PAPR in a 16-QAM short-reach intensity-modulated and direct-detection OOFDM (IMDD-OOFDM) system. The experimental results demonstrated that the hybrid scheme can reduce the PAPR by about 1.5, 2, 3 and 6 dB, and achieve 1.5, 1, 2.5 and 3 dB receiver sensitivity improvement compared to clipping, DFT-spread and Huffman coding and original OFDM signals, respectively, at an error vector magnitude (EVM) of -10 dB after transmission over 20 km standard single-mode fiber (SSMF). Furthermore, the throughput gain can be of the order of 30% by using the hybrid scheme compared with the cases of without applying the Huffman coding.

  5. Seven-channel digital telemetry system for monitoring and direct computer capturing of biological data.

    Science.gov (United States)

    Drewes, A M; Andreasen, A; Assentoft, J E; Nagel, O

    1993-09-01

    A seven-channel telemetry system for collection and display of biological data is presented. The system can amplify bioelectrical signals in the range of 2 microV to 200 mV and has a bandwidth of 0.1-80 Hz. After multiplexing, the signals are digitized with a resolution of 8 bits. The data are frequency modulated directly on a VHF transmitter. After receiving the data on a VHF receiver, they are routed directly to the RS232 input connector on the PC. Thereby the advantage of direct communication between the transmitter and the PC can be utilized. Expensive analog equipment is avoided and display of the signals on the PC screen as well as signal analysis can be performed. The system has been tested and was found to be stable and highly reliable.

  6. Recommended Research Directions for Improving the Validation of Complex Systems Models.

    Energy Technology Data Exchange (ETDEWEB)

    Vugrin, Eric D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Trucano, Timothy G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Swiler, Laura Painton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Finley, Patrick D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flanagan, Tatiana Paz [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Naugle, Asmeret Bier [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tsao, Jeffrey Y. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Verzi, Stephen Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    Improved validation for models of complex systems has been a primary focus over the past year for the Resilience in Complex Systems Research Challenge. This document describes a set of research directions that are the result of distilling those ideas into three categories of research -- epistemic uncertainty, strong tests, and value of information. The content of this document can be used to transmit valuable information to future research activities, update the Resilience in Complex Systems Research Challenge's roadmap, inform the upcoming FY18 Laboratory Directed Research and Development (LDRD) call and research proposals, and facilitate collaborations between Sandia and external organizations. The recommended research directions can provide topics for collaborative research, development of proposals, workshops, and other opportunities.

  7. 31 CFR 306.23 - Securities eligible to be held in the TREASURY DIRECT Book-entry Securities System.

    Science.gov (United States)

    2010-07-01

    ... TREASURY DIRECT Book-entry Securities System. 306.23 Section 306.23 Money and Finance: Treasury Regulations... Securities eligible to be held in the TREASURY DIRECT Book-entry Securities System. (a) Eligible issues. The... conversion to the TREASURY DIRECT Book-entry Securities System. The notice shall specify the period during...

  8. Changes in direct and indirect taxation in the process of the EU tax system reform

    Directory of Open Access Journals (Sweden)

    Miletić Vesna

    2015-01-01

    Full Text Available Proceeding from the changes in direct and indirect taxation in the process of the EU tax system reform and the fact that new trends bring about vital social changes, the research in this area could add to the understanding of economic development of these countries. In the EU with its decentralized tax policy, changes in direct and indirect taxation are permanently implemented in the process of tax system reform. Harmonization of direct and indirect taxation in the EU is conducted by means of the adopted community law regulations. In the harmonization of direct taxation there is a tendency towards an increase of the level of fiscal coordination and elimination of barriers to the common market. Thus direct taxation reforms are limited to achieving higher level of coordination and preventing evasion and double taxation. The current policy is the result of the principle according to which fiscal competition has positive effects on reducing consumption and on the EU economic development. In the harmonization process the systems of indirect taxation are aligned particularly with excise duty and value added tax. Fiscal strategies in the reform process are mostly aimed at fiscal coordination, modernization, informative cooperation, evasion reduction and elimination of malpractices in fulfilling a VAT payment liability. Within the excise tax system minimal excise rates are determined and an environmentally-friendly policy is pursued. The main priorities of taxation changes within the harmonization process are in respect of evasion reduction and irrational fiscal competition on the EU market. A study of direct and indirect taxation changes in the process of the tax system reform is highly significant both from the aspect of efficient tax-system functioning, which results in achieving EU macroeconomic goals, and from the aspect of single states' interests in the process of transition and accession.

  9. GAIN Technology Workshops Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Braase, Lori Ann [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    National and global demand for nuclear energy is increasing and United States (U.S.) global leadership is eroding. There is a sense of urgency with respect to the deployment of the innovative nuclear energy technologies. The Gateway for Accelerated Innovation in Nuclear (GAIN) initiative is based on the simultaneous achievement of three strategic goals. The first is maintaining global technology leadership within the U.S. Department of Energy (DOE). The second is enabling global industrial leadership for nuclear vendors and suppliers. The third is focused on utility optimization of nuclear energy within the clean energy portfolio. An effective public-private partnership is required to achieve these goals. DOEs recognizes the recent sense of urgency new developers and investors have in getting their concepts to market. They know that time to market for nuclear technology takes too long and the facilities needed to conduct the necessary research, development and demonstration (RD&D) activities are very expensive to develop and maintain. Early technologies, in the lower technology readiness levels (TRL) need materials testing, analysis, modeling, code development, etc., most of which currently exists in the DOE national laboratory system. However, mature technologies typically need large component testing and demonstration facilities, which are expensive and long-lead efforts. By understanding the needs of advanced nuclear technology developers, GAIN will connect DOE national laboratory capabilities (e.g., facilities, expertise, materials, and data) with industry RD&D needs. In addition, GAIN is working with the Nuclear Regulatory Commission (NRC) to streamline processes and increase understanding of the licensing requirements for advanced reactors.

  10. GAIN Technology Workshops Summary Report

    International Nuclear Information System (INIS)

    Braase, Lori Ann

    2016-01-01

    National and global demand for nuclear energy is increasing and United States (U.S.) global leadership is eroding. There is a sense of urgency with respect to the deployment of the innovative nuclear energy technologies. The Gateway for Accelerated Innovation in Nuclear (GAIN) initiative is based on the simultaneous achievement of three strategic goals. The first is maintaining global technology leadership within the U.S. Department of Energy (DOE). The second is enabling global industrial leadership for nuclear vendors and suppliers. The third is focused on utility optimization of nuclear energy within the clean energy portfolio. An effective public-private partnership is required to achieve these goals. DOEs recognizes the recent sense of urgency new developers and investors have in getting their concepts to market. They know that time to market for nuclear technology takes too long and the facilities needed to conduct the necessary research, development and demonstration (RD&D) activities are very expensive to develop and maintain. Early technologies, in the lower technology readiness levels (TRL) need materials testing, analysis, modeling, code development, etc., most of which currently exists in the DOE national laboratory system. However, mature technologies typically need large component testing and demonstration facilities, which are expensive and long-lead efforts. By understanding the needs of advanced nuclear technology developers, GAIN will connect DOE national laboratory capabilities (e.g., facilities, expertise, materials, and data) with industry RD&D needs. In addition, GAIN is working with the Nuclear Regulatory Commission (NRC) to streamline processes and increase understanding of the licensing requirements for advanced reactors.

  11. Acting to gain information

    Science.gov (United States)

    Rosenchein, Stanley J.; Burns, J. Brian; Chapman, David; Kaelbling, Leslie P.; Kahn, Philip; Nishihara, H. Keith; Turk, Matthew

    1993-01-01

    This report is concerned with agents that act to gain information. In previous work, we developed agent models combining qualitative modeling with real-time control. That work, however, focused primarily on actions that affect physical states of the environment. The current study extends that work by explicitly considering problems of active information-gathering and by exploring specialized aspects of information-gathering in computational perception, learning, and language. In our theoretical investigations, we analyzed agents into their perceptual and action components and identified these with elements of a state-machine model of control. The mathematical properties of each was developed in isolation and interactions were then studied. We considered the complexity dimension and the uncertainty dimension and related these to intelligent-agent design issues. We also explored active information gathering in visual processing. Working within the active vision paradigm, we developed a concept of 'minimal meaningful measurements' suitable for demand-driven vision. We then developed and tested an architecture for ongoing recognition and interpretation of visual information. In the area of information gathering through learning, we explored techniques for coping with combinatorial complexity. We also explored information gathering through explicit linguistic action by considering the nature of conversational rules, coordination, and situated communication behavior.

  12. Direct costs of emergency medical care: a diagnosis-based case-mix classification system.

    Science.gov (United States)

    Baraff, L J; Cameron, J M; Sekhon, R

    1991-01-01

    To develop a diagnosis-based case mix classification system for emergency department patient visits based on direct costs of care designed for an outpatient setting. Prospective provider time study with collection of financial data from each hospital's accounts receivable system and medical information, including discharge diagnosis, from hospital medical records. Three community hospital EDs in Los Angeles County during selected times in 1984. Only direct costs of care were included: health care provider time, ED management and clerical personnel excluding registration, nonlabor ED expense including supplies, and ancillary hospital services. Indirect costs for hospitals and physicians, including depreciation and amortization, debt service, utilities, malpractice insurance, administration, billing, registration, and medical records were not included. Costs were derived by valuing provider time based on a formula using annual income or salary and fringe benefits, productivity and direct care factors, and using hospital direct cost to charge ratios. Physician costs were based on a national study of emergency physician income and excluded practice costs. Patients were classified into one of 216 emergency department groups (EDGs) on the basis of the discharge diagnosis, patient disposition, age, and the presence of a limited number of physician procedures. Total mean direct costs ranged from $23 for follow-up visit to $936 for trauma, admitted, with critical care procedure. The mean total direct costs for the 16,771 nonadmitted patients was $69. Of this, 34% was for ED costs, 45% was for ancillary service costs, and 21% was for physician costs. The mean total direct costs for the 1,955 admitted patients was $259. Of this, 23% was for ED costs, 63% was for ancillary service costs, and 14% was for physician costs. Laboratory and radiographic services accounted for approximately 85% of all ancillary service costs and 38% of total direct costs for nonadmitted patients

  13. Directed clustering coefficient as a measure of systemic risk in complex banking networks

    Science.gov (United States)

    Tabak, Benjamin M.; Takami, Marcelo; Rocha, Jadson M. C.; Cajueiro, Daniel O.; Souza, Sergio R. S.

    2014-01-01

    Recent literature has focused on the study of systemic risk in complex networks. It is clear now, after the crisis of 2008, that the aggregate behavior of the interaction among agents is not straightforward and it is very difficult to predict. Contributing to this debate, this paper shows that the directed clustering coefficient may be used as a measure of systemic risk in complex networks. Furthermore, using data from the Brazilian interbank network, we show that the directed clustering coefficient is negatively correlated with domestic interest rates.

  14. Geometric detection of coupling directions by means of inter-system recurrence networks

    International Nuclear Information System (INIS)

    Feldhoff, Jan H.; Donner, Reik V.; Donges, Jonathan F.; Marwan, Norbert; Kurths, Jürgen

    2012-01-01

    We introduce a geometric method for identifying the coupling direction between two dynamical systems based on a bivariate extension of recurrence network analysis. Global characteristics of the resulting inter-system recurrence networks provide a correct discrimination for weakly coupled Rössler oscillators not yet displaying generalised synchronisation. Investigating two real-world palaeoclimate time series representing the variability of the Asian monsoon over the last 10,000 years, we observe indications for a considerable influence of the Indian summer monsoon on climate in Eastern China rather than vice versa. The proposed approach can be directly extended to studying K>2 coupled subsystems.

  15. Directional solidification and characterization of the Al Nb2 - Al3 Nb eutectic system

    International Nuclear Information System (INIS)

    Trevisan, Eduardo A.O.; Andreotti, Fabio; Caram, Rubens

    1996-01-01

    The manufacturing of components to operate at high temperatures requires the use of metallic materials which can keep satisfactory mechanical and chemical properties, even at temperatures beyond 1000 deg C. An interesting alternative is the use of directionally solidified eutectic alloys. The eutectic alloy solidification makes possible the production of 'in situ' composite. A potentially useful system for manufacturing structural materials is the Al-Nb eutectic system. The aim of this work is to present the directional solidification of the Al-Nb eutectic alloy. (author)

  16. Decentralized adaptive control of interconnected nonlinear systems with unknown control directions.

    Science.gov (United States)

    Huang, Jiangshuai; Wang, Qing-Guo

    2018-03-01

    In this paper, we propose a decentralized adaptive control scheme for a class of interconnected strict-feedback nonlinear systems without a priori knowledge of subsystems' control directions. To address this problem, a novel Nussbaum-type function is proposed and a key theorem is drawn which involves quantifying the interconnections of multiple Nussbaum-type functions of the subsystems with different control directions in a single inequality. Global stability of the closed-loop system and asymptotic stabilization of subsystems' output are proved and a simulation example is given to illustrate the effectiveness of the proposed control scheme. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Design of a Solar Motor Drive System Fed by a Direct-Connected Photovoltaic Array

    Directory of Open Access Journals (Sweden)

    AYDOGMUS, O.

    2012-08-01

    Full Text Available A solar motor pump drive system is modeled and simulated. The proposed drive system does not require any kind of energy storage system and dc-dc converter. The system is connected directly to a photovoltaic (PV array. Thus, a low cost solar system can be achieved. A vector controlled Permanent Magnet Synchronous Motor (PMSM is used as a solar motor to increase the efficiency of system. The motor is designed for a low rated voltage level about 24V. The hill climbing MPPT method is used for balanced the motor power and PV power to obtain a high efficiency. The results are performed by using MATLAB/SimPowerSystem blocks. In addition, the PV array is modeled to allow for the possibility of running as on-line adjustable in simulation environment without using lookup table. The performances of motor, MPPT and drive system are analyzed in different conditions as temperature and irradiation of PV array.

  18. Direct Heat-Flux Measurement System (MDF) for Solar central Receiver Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ballestrin, J.

    2001-07-01

    A direct flux measurement system, MDF, has been designed, constructed and mounted on top of the SSPS-CRS tower at the Plataforma Solar de Almeria (PSA) in addition to an indirect flux measurement system based on a CCD camera. It's one of the main future objectives to compare systematically both measurements of the concentrated solar power, increasing in this way the confidence in the estimate of this quantity. Today everything is prepared to perform the direct flux measurement on the aperture of solar receivers: calorimeter array, data acquisition system and software. the geometry of the receiver determines the operation and analysis procedures to obtain the indecent power onto the defined area. The study of previous experiences with direct flux measurement systems ha been useful to define a new simpler and more accurate system. A description of each component of the MDF system is included, focusing on the heat-flux sensors or calorimeters, which enables these measurements to be done in a few seconds without water-cooling. The incident solar power and the spatial flux distribution on the aperture of the volumetric receiver Hitrec II are supplied by the above-mentioned MDF system. The first results obtained during the evaluation of this solar receiver are presented including a sunrise-sunset test. All these measurements have been concentrated in one coefficient that describes the global behavior of the Solar Power Plant. (Author) 18 refs.

  19. Leading Gainful Employment Metric Reporting

    Science.gov (United States)

    Powers, Kristina; MacPherson, Derek

    2016-01-01

    This chapter will address the importance of intercampus involvement in reporting of gainful employment student-level data that will be used in the calculation of gainful employment metrics by the U.S. Department of Education. The authors will discuss why building relationships within the institution is critical for effective gainful employment…

  20. Direct and indirect economics of wind energy systems relative to fuel based systems

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, B

    1977-01-01

    It is shown that the addition of an energy-storage system of modest capacity, to a wind energy generator, provides a total-wind-energy electricity-generating system as dependable as current alternative means of producing electricity. It is further shown, based on projections of the mass-production costs of wind-energy generators and energy-storage systems, that such combined systems, as well as fuel-saving generators without storage, appear economically competitive to the alternatives, provided the comparison is made over the entire life cycle of the systems.

  1. A Self-Supported Direct Borohydride-Hydrogen Peroxide Fuel Cell System

    Directory of Open Access Journals (Sweden)

    Ashok K. Shukla

    2009-04-01

    Full Text Available A self-supported direct borohydride-hydrogen peroxide fuel cell system with internal manifolds and an auxiliary control unit is reported. The system, while operating under ambient conditions, delivers a peak power of 40 W with about 2 W to run the auxiliary control unit. A critical cause and effect analysis, on the data for single cells and stack, suggests the optimum concentrations of fuel and oxidant to be 8 wt. % NaBH4 and 2 M H2O2, respectively in extending the operating time of the system. Such a fuel cell system is ideally suited for submersible and aerospace applications where anaerobic conditions prevail.

  2. A digital computer simulation and study of a direct-energy-transfer power-conditioning system

    Science.gov (United States)

    Burns, W. W., III; Owen, H. A., Jr.; Wilson, T. G.; Rodriguez, G. E.; Paulkovich, J.

    1975-01-01

    An investigation of the behavior of the power-conditioning system as a whole is a necessity to ensure the integrity of the aggregate system in the case of space applications. An approach for conducting such an investigation is considered. A description is given of the application of a general digital analog simulator program to the study of an aggregate power-conditioning system which is being developed for use on the International Ultraviolet Explorer spacecraft. The function of the direct energy transfer system studied involves a coupling of a solar array through a main distribution bus to the spacecraft electrical loads.

  3. Direct renin inhibition — a new way of targeting the renin system

    Directory of Open Access Journals (Sweden)

    Morris J Brown

    2006-06-01

    Full Text Available The renin system plays a key role in the pathology of hypertension and is influenced, both directly and indirectly, by most antihypertensive agents. The system is the target of several established classes of antihypertensive agents including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta-blockers. Of currently available drugs, only the beta-blockers suppress renin secretion, but these also reduce heart rate and cardiac output. Calcium channel blockers and diuretics cause a modest activation of the renin system secondary to the fall in renal afferent arteriolar pressure and reduction in filtered sodium load. Aliskiren is the first orally available direct inhibitor that blocks the renin system at its rate limiting step and is shown to reduce angiotensin I and II and plasma renin activity.

  4. Influence of Functionality on Direct Arylation of Model Systems as a Route Toward Fluorinated Copolymers via Direct Arylation Polymerization (DArP)

    DEFF Research Database (Denmark)

    Livi, Francesco; Gobalasingham, Nemal S.; Bundgaard, Eva

    2015-01-01

    A screening of direct arylation conditions on amodel small molecule system is carried out to develop suitableconditions for the direct arylation polymerization (DArP) of fluorinatedcopolymers, which are incompatible with conditionspreviously utilized successfully for nonfluorinated systems. Themo......,4-phenylene)dithiophene. Polymers arefree of β-defects and significant homocoupling. This work furtherunderscores the attractive simplicity, relevance, and easeof DArP while reconfirming its broad compatibility withincreasingly popular fluorinated copolymers....

  5. Central gain control in tinnitus and hyperacusis

    Directory of Open Access Journals (Sweden)

    Benjamin D Auerbach

    2014-10-01

    Full Text Available Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders.

  6. Central Gain Control in Tinnitus and Hyperacusis

    Science.gov (United States)

    Auerbach, Benjamin D.; Rodrigues, Paulo V.; Salvi, Richard J.

    2014-01-01

    Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders. PMID:25386157

  7. System Efficiency Improvement for Electric Vehicles Adopting a Permanent Magnet Synchronous Motor Direct Drive System

    Directory of Open Access Journals (Sweden)

    Chengming Zhang

    2017-12-01

    Full Text Available To improve the endurance mileage of electric vehicles (EVs, it is important to decrease the energy consumption of the Permanent Magnet Synchronous Motor (PMSM drive system. This paper proposes a novel loss optimization control strategy named system efficiency improvement control which can optimize both inverter and motor losses. A nonlinear power converter loss model is built to fit the nonlinear characteristics of power devices. This paper uses double Fourier integral analysis to analytically calculate the fundamental and harmonic components of motor current by which the fundamental motor loss and harmonic motor loss can be accurately analyzed. From these loss models, a whole-frequency-domain system loss model is derived and presented. Based on the system loss model, the system efficiency improvement control method applies the genetic algorithm to adjust the motor current and PWM frequency together to optimize the inverter and motor losses by which the system efficiency can be significantly improved without seriously influence on the system stability over the whole operation range of EVs. The optimal effects of system efficiency is verified by the experimental results in both Si-IGBT-based PMSM system and SiC-MOSFET-based system.

  8. Gain saturation of nickel-like silver and tin x-ray lasers by use of a tabletop pumping laser system

    International Nuclear Information System (INIS)

    Kawachi, Tetsuya; Kado, Masataka; Tanaka, Momoko; Sasaki, Akira; Hasegawa, Noboru; Namba, Sinichi; Nagashima, Keisuke; Lu Peixiang; Takahashi, Kenjiro; Tai Renzhong; Kishimoto, Maki; Koike, Masato; Daido, Hiroyuki; Kato, Yoshiaki; Kilpio, Alexander V.; Tang Huajing

    2002-01-01

    Silver and tin slab targets were irradiated by line-focused chirped pulse amplification glass laser light. In this experiment, the laser pulses consisted of two pulses with 4 ps duration, separated by 1.2 ns. Strong amplification in the nickel-like silver and tin x-ray lasers at the wavelengths of 13.9 and 12.0 nm was demonstrated with pumping energy of 12 and 14 J, respectively, and gain-saturation behavior could be seen. A hydrodynamics simulation coupled with a collisional-radiative model was performed under the present experimental conditions, and the calculated result was compared with the experimental results

  9. 75 FR 60632 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Direct Final Rule

    Science.gov (United States)

    2010-10-01

    ... Waste Management System; Identification and Listing of Hazardous Waste; Direct Final Rule AGENCY... management and treatment of several F- and K-waste codes. These waste codes are F037, F038, K048, K049, K051... released from the waste, plausible and specific types of management of the petitioned waste, the quantities...

  10. 16-level differential phase shift keying (D16PSK) in direct detection optical communication systems

    DEFF Research Database (Denmark)

    Sambaraju, R.; Tokle, Torger; Jensen, J.B.

    2006-01-01

    Optical 16-level differential phase shift keying (D16PSK) carrying four bits for every symbol is proposed for direct detection optical communication systems. Transmitter and receiver schematics are presented, and the receiver sensitivity is discussed. We numerically investigate the impact...

  11. About direct CP violation in the system of K0 mesons

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    2012-01-01

    This work is devoted to computation of the parameter of direct CP violation by the weak interactions in the system of K 0 mesons at K 1 0 -, K 2 0 -meson mixings and oscillations via K S -, K L -meson states

  12. Direct Student Loans: Overpayments during the Department of Education's Conversion to a New Payment System.

    Science.gov (United States)

    Joyner, Carlotta C.

    This report addresses concerns that the Department of Education may have erroneously made overpayments of as much as $400 million to schools participating in the William D. Ford Federal Direct Loan Program (FDLP) during the Department's conversion to a new computerized payment system. The investigation found that because the transition to the new…

  13. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...

  14. Direct evaluation of free energy for large system through structure integration approach.

    Science.gov (United States)

    Takeuchi, Kazuhito; Tanaka, Ryohei; Yuge, Koretaka

    2015-09-30

    We propose a new approach, 'structure integration', enabling direct evaluation of configurational free energy for large systems. The present approach is based on the statistical information of lattice. Through first-principles-based simulation, we find that the present method evaluates configurational free energy accurately in disorder states above critical temperature.

  15. Direct Adaptive Control of a Class of Nonlinear Discrete-Time Systems

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon

    2004-01-01

    In this paper we deal with direct adaptive control of a specific class of discrete-time SISO systems, where the nonlinearities are convex and an upper bound is known. We use a control law based on a linear combination of a set of globally uniformly bounded basis functions with compact support, wh...

  16. Direct Sensor Orientation of a Land-Based Mobile Mapping System

    Directory of Open Access Journals (Sweden)

    Yu-Hua Li

    2011-07-01

    Full Text Available A land-based mobile mapping system (MMS is flexible and useful for the acquisition of road environment geospatial information. It integrates a set of imaging sensors and a position and orientation system (POS. The positioning quality of such systems is highly dependent on the accuracy of the utilized POS. This limitation is the major drawback due to the elevated cost associated with high-end GPS/INS units, particularly the inertial system. The potential accuracy of the direct sensor orientation depends on the architecture and quality of the GPS/INS integration process as well as the validity of the system calibration (i.e., calibration of the individual sensors as well as the system mounting parameters. In this paper, a novel single-step procedure using integrated sensor orientation with relative orientation constraint for the estimation of the mounting parameters is introduced. A comparative analysis between the proposed single-step and the traditional two-step procedure is carried out. Moreover, the estimated mounting parameters using the different methods are used in a direct geo-referencing procedure to evaluate their performance and the feasibility of the implemented system. Experimental results show that the proposed system using single-step system calibration method can achieve high 3D positioning accuracy.

  17. Direct sensor orientation of a land-based mobile mapping system.

    Science.gov (United States)

    Rau, Jiann-Yeou; Habib, Ayman F; Kersting, Ana P; Chiang, Kai-Wei; Bang, Ki-In; Tseng, Yi-Hsing; Li, Yu-Hua

    2011-01-01

    A land-based mobile mapping system (MMS) is flexible and useful for the acquisition of road environment geospatial information. It integrates a set of imaging sensors and a position and orientation system (POS). The positioning quality of such systems is highly dependent on the accuracy of the utilized POS. This limitation is the major drawback due to the elevated cost associated with high-end GPS/INS units, particularly the inertial system. The potential accuracy of the direct sensor orientation depends on the architecture and quality of the GPS/INS integration process as well as the validity of the system calibration (i.e., calibration of the individual sensors as well as the system mounting parameters). In this paper, a novel single-step procedure using integrated sensor orientation with relative orientation constraint for the estimation of the mounting parameters is introduced. A comparative analysis between the proposed single-step and the traditional two-step procedure is carried out. Moreover, the estimated mounting parameters using the different methods are used in a direct geo-referencing procedure to evaluate their performance and the feasibility of the implemented system. Experimental results show that the proposed system using single-step system calibration method can achieve high 3D positioning accuracy.

  18. Effect of direct eye contact in PTSD related to interpersonal trauma: an fMRI study of activation of an innate alarm system.

    Science.gov (United States)

    Steuwe, Carolin; Daniels, Judith K; Frewen, Paul A; Densmore, Maria; Pannasch, Sebastian; Beblo, Thomas; Reiss, Jeffrey; Lanius, Ruth A

    2014-01-01

    In healthy individuals, direct eye contact initially leads to activation of a fast subcortical pathway, which then modulates a cortical route eliciting social cognitive processes. The aim of this study was to gain insight into the neurobiological effects of direct eye-to-eye contact using a virtual reality paradigm in individuals with posttraumatic stress disorder (PTSD) related to prolonged childhood abuse. We examined 16 healthy comparison subjects and 16 patients with a primary diagnosis of PTSD using a virtual reality functional magnetic resonance imaging paradigm involving direct vs averted gaze (happy, sad, neutral) as developed by Schrammel et al. in 2009. Irrespective of the displayed emotion, controls exhibited an increased blood oxygenation level-dependent response during direct vs averted gaze within the dorsomedial prefrontal cortex, left temporoparietal junction and right temporal pole. Under the same conditions, individuals with PTSD showed increased activation within the superior colliculus (SC)/periaqueductal gray (PAG) and locus coeruleus. Our findings suggest that healthy controls react to the exposure of direct gaze with an activation of a cortical route that enhances evaluative 'top-down' processes underlying social interactions. In individuals with PTSD, however, direct gaze leads to sustained activation of a subcortical route of eye-contact processing, an innate alarm system involving the SC and the underlying circuits of the PAG.

  19. Transient Dynamics of Electric Power Systems: Direct Stability Assessment and Chaotic Motions

    Science.gov (United States)

    Chu, Chia-Chi

    A power system is continuously experiencing disturbances. Analyzing, predicting, and controlling transient dynamics, which describe transient behaviors of the power system following disturbances, is a major concern in the planning and operation of a power utility. Important conclusions and decisions are made based on the result of system transient behaviors. As today's power network becomes highly interconnected and much more complex, it has become essential to enhance the fundamental understanding of transient dynamics, and to develop fast and reliable computational algorithms. In this thesis, we emphasize mathematical rigor rather than physical insight. Nonlinear dynamical system theory is applied to study two fundamental topics: direct stability assessment and chaotic motions. Conventionally, power system stability is determined by calculating the time-domain transient behaviors for a given disturbance. In contrast, direct methods identify whether or not the system will remain stable once the disturbance is removed by comparing the corresponding energy value of the post-fault system to a calculated threshold value. Direct methods not only avoid the time-consuming numerical integration of the time domain approach, but also provide a quantitative measure of the degree of system stability. We present a general framework for the theoretical foundations of direct methods. Canonical representations of network-reduction models as well as network-preserving models are proposed to facilitate the analysis and the construction of energy functions of various power system models. An advanced and practical method, called the boundary of stability region based controlling unstable equilibrium point method (BCU method), of computing the controlling unstable equilibrium point is proposed along with its theoretical foundation. Numerical solution algorithms capable of supporting on-line applications of direct methods are provided. Further possible improvements and enhancements are

  20. Human-directed local autonomy for motion guidance and coordination in an intelligent manufacturing system

    Science.gov (United States)

    Alford, W. A.; Kawamura, Kazuhiko; Wilkes, Don M.

    1997-12-01

    This paper discusses the problem of integrating human intelligence and skills into an intelligent manufacturing system. Our center has jointed the Holonic Manufacturing Systems (HMS) Project, an international consortium dedicated to developing holonic systems technologies. One of our contributions to this effort is in Work Package 6: flexible human integration. This paper focuses on one activity, namely, human integration into motion guidance and coordination. Much research on intelligent systems focuses on creating totally autonomous agents. At the Center for Intelligent Systems (CIS), we design robots that interact directly with a human user. We focus on using the natural intelligence of the user to simplify the design of a robotic system. The problem is finding ways for the user to interact with the robot that are efficient and comfortable for the user. Manufacturing applications impose the additional constraint that the manufacturing process should not be disturbed; that is, frequent interacting with the user could degrade real-time performance. Our research in human-robot interaction is based on a concept called human directed local autonomy (HuDL). Under this paradigm, the intelligent agent selects and executes a behavior or skill, based upon directions from a human user. The user interacts with the robot via speech, gestures, or other media. Our control software is based on the intelligent machine architecture (IMA), an object-oriented architecture which facilitates cooperation and communication among intelligent agents. In this paper we describe our research testbed, a dual-arm humanoid robot and human user, and the use of this testbed for a human directed sorting task. We also discuss some proposed experiments for evaluating the integration of the human into the robot system. At the time of this writing, the experiments have not been completed.

  1. System and method of providing quick thermal comfort with reduced energy by using directed spot conditioning

    Science.gov (United States)

    Wang, Mingyu; Kadle, Prasad S.; Ghosh, Debashis; Zima, Mark J.; Wolfe, IV, Edward; Craig, Timothy D

    2016-10-04

    A heating, ventilation, and air conditioning (HVAC) system and a method of controlling a HVAC system that is configured to provide a perceived comfortable ambient environment to an occupant seated in a vehicle cabin. The system includes a nozzle configured to direct an air stream from the HVAC system to the location of a thermally sensitive portion of the body of the occupant. The system also includes a controller configured to determine an air stream temperature and an air stream flow rate necessary to establish the desired heat supply rate for the sensitive portion and provide a comfortable thermal environment by thermally isolating the occupant from the ambient vehicle cabin temperature. The system may include a sensor to determine the location of the sensitive portion. The nozzle may include a thermoelectric device to heat or cool the air stream.

  2. evelopment of a boiling water reactor fault diagnostic system with a signed directed graph method

    International Nuclear Information System (INIS)

    Chen, M.; Yu, C.C.; Liou, C.T.; Liao, L.Y.

    1990-01-01

    The fault diagnostic system for a nuclear power reactor is expected to be a useful decision support system for the operators during transients and accident conditions. A considerable research effort has been devoted to the development of automated fault diagnostic systems. One major approach, which has been widely used in chemical engineering, is to identify the possible causes of process disturbance using a logic-oriented method called signed directed graph (SDG). A knowledge based system was developed with the rules derived from the SDG representation. The SDG for the Chinshan nuclear power plant, which is a typical boiling water reactor, is established. The personal consultant system is used as the expert system development tool in this paper

  3. Reliability analysis of an LCL tuned track segmented bi-directional inductive power transfer system

    DEFF Research Database (Denmark)

    Asif Iqbal, S. M.; Madawala, U. K.; Thrimawithana, D. J.

    2013-01-01

    Bi-directional Inductive Power Transfer (BDIPT) technique is suitable for renewable energy based applications such as electric vehicles (EVs), for the implementation of vehicle-to-grid (V2G) systems. Recently, more efforts have been made by researchers to improve both efficiency and reliability...... of renewable energy systems to further enhance their economical sustainability. This paper presents a comparative reliability study between a typical BDIPT system and an individually controlled segmented BDIPT system. Steady state thermal simulation results are provided for different output power levels...... for a 1.5 kW BDIPT system in a MATLAB/Simulink environment. Reliability parameters such as failure rate and mean time between failures (MTBF) are compared between the two systems. A nonlinear programming (NP) model is developed for optimizing charging schedule for a stationery EV. A case study of EV...

  4. Biomass Power Generation through Direct Integration of Updraft Gasifier and Stirling Engine Combustion System

    Directory of Open Access Journals (Sweden)

    Jai-Houng Leu

    2010-01-01

    Full Text Available Biomass is the largest renewable energy source in the world. Its importance grows gradually in the future energy market. Since most biomass sources are low in energy density and are widespread in space, small-scale biomass conversion system is therefore more competitive than a large stand-alone conversion plant. The current study proposes a small-scale solid biomass power system to explore the viability of direct coupling of an updraft fixed bed gasifier with a Stirling engine. The modified updraft fixed bed gasifier employs an embedded combustor inside the gasifier to fully combust the synthetic gas generated by the gasifier. The flue gas produced by the synthetic gas combustion inside the combustion tube is piped directly to the heater head of the Stirling engine. The engine will then extract and convert the heat contained in the flue gas into electricity automatically. Output depends on heat input. And, the heat input is proportional to the flow rate and temperature of the flue gas. The preliminary study of the proposed direct coupling of an updraft gasifier with a 25 kW Stirling engine demonstrates that full power output could be produced by the current system. It could be found from the current investigation that no auxiliary fuel is required to operate the current system smoothly. The proposed technology and units could be considered as a viable solid biomass power system.

  5. Biological effects of direct and indirect manipulation of the fascial system. Narrative review.

    Science.gov (United States)

    Parravicini, Giovanni; Bergna, Andrea

    2017-04-01

    Osteopathic Manipulative Treatment (OMT) is effective in improving function, movement and restoring pain conditions. Despite clinical results, the mechanisms of how OMT achieves its' effects remain unclear. The fascial system is described as a tensional network that envelops the human body. Direct or indirect manipulations of the fascial system are a distinctive part of OMT. This review describes the biological effects of direct and indirect manipulation of the fascial system. Literature search was performed in February 2016 in the electronic databases: Cochrane, Medline, Scopus, Ostmed, Pedro and authors' publications relative to Fascia Research Congress Website. Manipulation of the fascial system seems to interfere with some cellular processes providing various pro-inflammatory and anti-inflammatory cells and molecules. Despite growing research in the osteopathic field, biological effects of direct or indirect manipulation of the fascial system are not conclusive. To elevate manual medicine as a primary intervention in clinical settings, it's necessary to clarify how OMT modalities work in order to underpin their clinical efficacies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Alternatives for blocking direct current in AC system neutrals at the Radisson/LG2 complex

    International Nuclear Information System (INIS)

    Eitzmann, M.A.; Walling, R.A.; Sublich, M.; Kah, A.; Huynh, H.; Granger, M.; Dutil, A.

    1992-01-01

    Severe offset saturation results from the passage of direct current through power transformers. Such direct current can arise from geomagnetic disturbances, or resistive coupling of the substation ground to HVDC earth electrodes. This paper documents the development of alternative approaches for the design and application of blocking devices placed between transformer neutrals and the substation ground. System constraints on the impedance and overvoltage limitation of the neutral blocking device (NBD) are covered. Three alternative NBD schemes are developed and optimized. System performance of the NBD is discussed, as are the practical implementation considerations for this unconventional equipment application. Although the paper focuses on the NBD requirements of Hydro-Quebec's Radisson/LG2 complex, the fundamental information is applicable to any situation where dc must be clocked from a power transformer neutral in a system designed for effectively-grounded operation

  7. Can LENR Energy Gains Exceed 1000?

    Science.gov (United States)

    Nagel, David J.

    2011-03-01

    Energy gain is defined as the energy realized from reactions divided by the energy required to produce those reactions. Low Energy Nuclear Reactions (LENR) have already been measured to significantly exceed the energy gain of 10 projected from ITER,possibly 15 years from now. Electrochemical experiments using the Pd-D system have shown energy gains exceeding 10. Gas phase experiments with the Ni-H system were reported to yield energy gains of over 100. Neither of these reports has been adequately verified or reproduced. However, the question in the title still deserves consideration. If, as thought by many, it is possible to trigger nuclear reactions that yield MeV energies with chemical energies of the order of eV, then the most optimistic expectation is that LENR gains could approach one million. Hence, the very tentative answer to the question above is yes. However, if LENR could be initiated with some energy cost, and then continue to ``burn,'' very high energy gains might be realized. Consider a match and a pile of dry logs. The phenomenon termed ``heat after death'' will be examined to see if it might be the initial evidence for nuclear ``burning.''

  8. Transient optical gain in germanium quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sangam; Lange, Christoph; Koester, Niko S.; Schaefer, Martin; Kira, Mackillo; Koch, Stephan W. [Faculty of Physics and Materials Sciences Center, Philipps-Universitaet Marburg (Germany); Chrastina, Daniel; Isella, Giovanni; Kaenel, Hans von [CNISM, Como (Italy); L-NESS, Dipartimento di Fisica del Politecnico di Milano, Como (Italy); Sigg, Hans [Laboratory for Micro and Nanotecnology, Paul Scherrer Institut, Villigen PSI (Switzerland)

    2010-07-01

    One of today's most-sought goals in semiconductor technology is the monolithic integration of microelectronics and photonics on Si. Optical gain is, in general, not expected for Si and Ge or its alloys due to the indirect nature of the band gap in this material system. Here, we show that Ge/SiGe QWs show transient optical gain and may thus be used as an optically-pumped amplifier at room temperature. Further, the nonequilibrium effects which govern the relaxation dynamics of the optically injected carrier distributions in this material were observed and analyzed using a microscopic many-body theory. Strong non-equilibrium gain was obtained on a sub-100 fs time scale. Long-lived gain arising from {gamma}-point transitions is overcompensated by a process bearing the character of free carrier absorption.

  9. Towards Small-Sized Long Tail Business with the Dual-Directed Recommendation System

    Science.gov (United States)

    Takahashi, Masakazu; Yamada, Takashi; Tsuda, Kazuhiko; Terano, Takao

    This paper describes a novel architecture to promote retail businesses using information recommendation systems. The main features of the architecture are 1) Dual-directed Recommendation system, 2) Portal site for three kinds of users: Producers, Retailers, and Consumers, which are considered to be Prosumers, and 3) Agent-based implementation. We have developed a web-based system DAIKOC (Dynamic Advisor for Information and Knowledge Oriented Communities) with the above architecture. In this paper, we focus on the recommendation functions to extract the items that will achieve the large sales in the future from the ID (IDentification)-POS (Point-Of-Sales) data.

  10. A portable inspection system to estimate direct glare of various LED modules

    Science.gov (United States)

    Chen, Po-Li; Liao, Chun-Hsiang; Li, Hung-Chung; Jou, Shyh-Jye; Chen, Han-Ting; Lin, Yu-Hsin; Tang, Yu-Hsiang; Peng, Wei-Jei; Kuo, Hui-Jean; Sun, Pei-Li; Lee, Tsung-Xian

    2015-07-01

    Glare is caused by both direct and indirect light sources and discomfort glare produces visual discomfort, annoyance, or loss in visual performance and visibility. Direct glare is caused by light sources in the field of view whereas reflected glare is caused by bright reflections from polished or glossy surfaces that are reflected toward an individual. To improve visual comfort of our living environment, a portable inspection system to estimate direct glare of various commercial LED modules with the range of color temperature from 3100 K to 5300 K was developed in this study. The system utilized HDR images to obtain the illumination distribution of LED modules and was first calibrated for brightness and chromaticity and corrected with flat field, dark-corner and curvature by the installed algorithm. The index of direct glare was then automatically estimated after image capturing, and the operator can recognize the performance of LED modules and the possible effects on human being once the index was out of expecting range. In the future, we expect that the quick-response smart inspection system can be applied in several new fields and market, such as home energy diagnostics, environmental lighting and UGR monitoring and popularize it in several new fields.

  11. Energy gains from lattice-enabled nuclear reactions

    International Nuclear Information System (INIS)

    Nagel, David J.

    2015-01-01

    The energy gain of a system is defined as the ratio of its output energy divided by the energy provided to operate the system. Most familiar systems have energy gains less than one due to various inefficiencies. By contrast, lattice-enabled nuclear reactions (LENR) offer high energy gains. Theoretical values in excess of 1000 are possible. Energy gains over 100 have already been reported. But, they have not yet been sustained for commercially significant durations. This article summarizes the current status of LENR energy gains. (author)

  12. Direct photon production and jet energy-loss in small systems

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Chun; Park, Chanwook [Department of Physics, McGill University, 3600 University Street, Montreal, QC, H3A 2T8 (Canada); Paquet, Jean-François [Department of Physics, McGill University, 3600 University Street, Montreal, QC, H3A 2T8 (Canada); Department of Physics & Astronomy, Stony Brook University, Stony Brook, NY 11733 (United States); Denicol, Gabriel S. [Department of Physics, McGill University, 3600 University Street, Montreal, QC, H3A 2T8 (Canada); Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Jeon, Sangyong; Gale, Charles [Department of Physics, McGill University, 3600 University Street, Montreal, QC, H3A 2T8 (Canada)

    2016-12-15

    Two types of penetrating probes, direct photon and QCD jets, are investigated in the background of a small and rapidly expanding droplet of quark-gluon plasma. The additional thermal electromagnetic radiation results in a ∼50% enhancement of the direct photons. In high multiplicity p+Pb collisions, jets can lose a sizeable fraction of their initial energy, leading to a charged hadron R{sub pA} of ∼0.8 at a transverse momentum around 10 GeV. Those two proposed measurements can help understand the apparent collective behaviour observed in small collision systems.

  13. Optimum concentric circular array antenna with high gain and side lobe reduction at 5.8 GHz

    Science.gov (United States)

    Zaid, Mohammed; Rafiqul Islam, Md; Habaebi, Mohamed H.; Zahirul Alam, AHM; Abdullah, Khaizuran

    2017-11-01

    The significance of high gain directional antennas stems from the need to cope up with the everyday progressing wireless communication systems. Due to low gain of the widely used microstrip antenna, combining multiple antennas in proper geometry increases the gain with good directive property. Over other array forms, this paper uses concentric circular array configuration for its compact structure and inherent symmetry in azimuth. This proposed array is composed of 9 elements on FR-4 substrate, which is designed for WLAN applications at 5.8GHz. Antenna Magus software is used for synthesis, while CST software is used for optimization. The proposed array is designed with optimum inter-element spacing and number of elements achieving a high directional gain of 15.7 dB compared to 14.2 dB of available literature, with a high reduction in side lobe level of -17.6 dB.

  14. Evolution of branched regulatory genetic pathways: directional selection on pleiotropic loci accelerates developmental system drift.

    Science.gov (United States)

    Johnson, Norman A; Porter, Adam H

    2007-01-01

    Developmental systems are regulated by a web of interacting loci. One common and useful approach in studying the evolution of development is to focus on classes of interacting elements within these systems. Here, we use individual-based simulations to study the evolution of traits controlled by branched developmental pathways involving three loci, where one locus regulates two different traits. We examined the system under a variety of selective regimes. In the case where one branch was under stabilizing selection and the other under directional selection, we observed "developmental system drift": the trait under stabilizing selection showed little phenotypic change even though the loci underlying that trait showed considerable evolutionary divergence. This occurs because the pleiotropic locus responds to directional selection and compensatory mutants are then favored in the pathway under stabilizing selection. Though developmental system drift may be caused by other mechanisms, it seems likely that it is accelerated by the same underlying genetic mechanism as that producing the Dobzhansky-Muller incompatibilities that lead to speciation in both linear and branched pathways. We also discuss predictions of our model for developmental system drift and how different selective regimes affect probabilities of speciation in the branched pathway system.

  15. Capital gains taxation under different tax regimes

    OpenAIRE

    Sureth, Caren; Langeleh, Dirk

    2005-01-01

    This paper investigates the influence of different systems of current income and capital gains taxation on investor's decision to either carry out an investment in corporate shares or to invest funds alternatively on the capital market. Three basic tax systems are analyzed, a classical corporate tax system with double taxation of profits on corporate and personal level, a shareholder relief system, that reduces double taxation completely. It can be shown that general analytical solutions for ...

  16. Radiation Resistance and Gain of Homogeneous Ring Quasi-Array

    DEFF Research Database (Denmark)

    Knudsen, H. L.

    1954-01-01

    In a previous paper homogeneous ring quasi-arrays of tangential or radial dipoles were introduced, i.e. systems of dipoles arranged equidistantly along a circle, the dipoles being oriented in tangential or radial directions and carrying currents with the same amplitude, but with a phase that incr......In a previous paper homogeneous ring quasi-arrays of tangential or radial dipoles were introduced, i.e. systems of dipoles arranged equidistantly along a circle, the dipoles being oriented in tangential or radial directions and carrying currents with the same amplitude, but with a phase...... that increases uniformly along the circle. Such quasi-arrays are azimuthally omnidirectional, and the radiated field will be mainly horizontally polarized and concentrated around the plane of the circle. In this paper expressions are obtained for the radiation resistance and the gain of homogeneous ring quasi...

  17. Contrast gain control in first- and second-order motion perception.

    Science.gov (United States)

    Lu, Z L; Sperling, G

    1996-12-01

    A novel pedestal-plus-test paradigm is used to determine the nonlinear gain-control properties of the first-order (luminance) and the second-order (texture-contrast) motion systems, that is, how these systems' responses to motion stimuli are reduced by pedestals and other masking stimuli. Motion-direction thresholds were measured for test stimuli consisting of drifting luminance and texture-contrast-modulation stimuli superimposed on pedestals of various amplitudes. (A pedestal is a static sine-wave grating of the same type and same spatial frequency as the moving test grating.) It was found that first-order motion-direction thresholds are unaffected by small pedestals, but at pedestal contrasts above 1-2% (5-10 x pedestal threshold), motion thresholds increase proportionally to pedestal amplitude (a Weber law). For first-order stimuli, pedestal masking is specific to the spatial frequency of the test. On the other hand, motion-direction thresholds for texture-contrast stimuli are independent of pedestal amplitude (no gain control whatever) throughout the accessible pedestal amplitude range (from 0 to 40%). However, when baseline carrier contrast increases (with constant pedestal modulation amplitude), motion thresholds increase, showing that gain control in second-order motion is determined not by the modulator (as in first-order motion) but by the carrier. Note that baseline contrast of the carrier is inherently independent of spatial frequency of the modulator. The drastically different gain-control properties of the two motion systems and prior observations of motion masking and motion saturation are all encompassed in a functional theory. The stimulus inputs to both first- and second-order motion process are normalized by feedforward, shunting gain control. The different properties arise because the modulator is used to control the first-order gain and the carrier is used to control the second-order gain.

  18. Experimental investigation of a multi-stage humidification-dehumidification desalination system heated directly by a cylindrical Fresnel lens solar concentrator

    International Nuclear Information System (INIS)

    Wu, Gang; Zheng, Hongfei; Ma, Xinglong; Kutlu, Cagri; Su, Yuehong

    2017-01-01

    Highlights: • A solar desalination system heated directly by curved Fresnel lens concentrator. • Desalination system is based on the humidification-dehumidification process. • Four-stage multi-effect desalination system is proposed. • Condensation latent heat and residual heat in the brine are recycled and reutilized. • The maximum yield and GOR of the unit can reach 3.4 kg/h and 2.1, respectively. - Abstract: This study demonstrates a multi-stage humidification-dehumidification (HDH) solar desalination system heated directly by a cylindrical Fresnel lens concentrator. In this novel system, the solar radiation is sent directly into desalination unit. That is to say, the solar receiver and the evaporator of the system are a whole in which the black fillers in seawater directly absorb the concentrated solar lights to heat the seawater film to produce the evaporation. The configuration and working processes of the proposed design are described in detail. In order to analyze its performance, a small solar desalination prototype unit incorporated with a cylindrical Fresnel lens concentrator was designed and built in our laboratory. Using three-stage isothermal tandem heating mode, the variation of the fresh water yield rate and the absorber temperature with time were measured experimentally and were compared with theoretical calculations. The experimental results show that the maximum yield of the unit is about 3.4 kg/h, the maximum gained output ratio (GOR) is about 2.1, when the average intensity of solar radiation is about 867 W/m"2. This study indicates that the proposed system has the characteristics of compact structure and GOR high. It still can be improved when the design and operation are optimized further.

  19. Review of High Gain FELs

    International Nuclear Information System (INIS)

    Shintake, Tsumoru

    2007-01-01

    For understanding on basic radiation mechanism of the high-gain FEL based on SASE, the author presents electron-crystal interpretation of FEL radiation. In the electron-crystal, electrons are localized at regularly spaced multi-layers, which represents micro-bunching, whose spacing is equal to the radiation wavelength, and the multi-layers are perpendicular to beam axis, thus, diffracted wave creates Bragg's spots in forward and backward directions. Due to the Doppler's effect, frequency of the back-scattered wave is up-converted, generates forwardly focused X-ray. The Bragg's effect contributes focusing the X-ray beam into a spot, thus peak power becomes extremely higher by factor of typically 107. This is the FEL radiation. As well known, the total numbers of scattered photons in Bragg's spots is equal to the total elastic scattering photons from the atoms contained in the crystal. Therefore, total power in the FEL laser is same as the spontaneous radiation power from the undulator for the same beam parameter. The FEL radiation phenomenon is simple interference effect. In today's presentations, we use the laser pointer, and we frequently experience difficulty in pointing precisely or steadily in one place on the screen, since the laser spot is very small and does not spread. Exactly same to this, X-ray FEL is a highly focused beam, and pointing stability dominates productivity of experiment, thus we need special care on beam stability from linear accelerator

  20. Develop Direct Geo-referencing System Based on Open Source Software and Hardware Platform

    Directory of Open Access Journals (Sweden)

    H. S. Liu

    2015-08-01

    Full Text Available Direct geo-referencing system uses the technology of remote sensing to quickly grasp images, GPS tracks, and camera position. These data allows the construction of large volumes of images with geographic coordinates. So that users can be measured directly on the images. In order to properly calculate positioning, all the sensor signals must be synchronized. Traditional aerial photography use Position and Orientation System (POS to integrate image, coordinates and camera position. However, it is very expensive. And users could not use the result immediately because the position information does not embed into image. To considerations of economy and efficiency, this study aims to develop a direct geo-referencing system based on open source software and hardware platform. After using Arduino microcontroller board to integrate the signals, we then can calculate positioning with open source software OpenCV. In the end, we use open source panorama browser, panini, and integrate all these to open source GIS software, Quantum GIS. A wholesome collection of data – a data processing system could be constructed.

  1. Develop Direct Geo-referencing System Based on Open Source Software and Hardware Platform

    Science.gov (United States)

    Liu, H. S.; Liao, H. M.

    2015-08-01

    Direct geo-referencing system uses the technology of remote sensing to quickly grasp images, GPS tracks, and camera position. These data allows the construction of large volumes of images with geographic coordinates. So that users can be measured directly on the images. In order to properly calculate positioning, all the sensor signals must be synchronized. Traditional aerial photography use Position and Orientation System (POS) to integrate image, coordinates and camera position. However, it is very expensive. And users could not use the result immediately because the position information does not embed into image. To considerations of economy and efficiency, this study aims to develop a direct geo-referencing system based on open source software and hardware platform. After using Arduino microcontroller board to integrate the signals, we then can calculate positioning with open source software OpenCV. In the end, we use open source panorama browser, panini, and integrate all these to open source GIS software, Quantum GIS. A wholesome collection of data - a data processing system could be constructed.

  2. Air conditioning system and component therefore distributing air flow from opposite directions

    Science.gov (United States)

    Obler, H. D.; Bauer, H. B. (Inventor)

    1974-01-01

    The air conditioning system comprises a plurality of separate air conditioning units coupled to a common supply duct such that air may be introduced into the supply duct in two opposite flow directions. A plurality of outlets such as registers or auxiliary or branch ducts communicate with the supply duct and valve means are disposed in the supply duct at at least some of the outlets for automatically channelling a controllable amount of air from the supply duct to the associated outlet regardless of the direction of air flow within the supply duct. The valve means comprises an automatic air volume control apparatus for distribution within the air supply duct into which air may be introduced from two opposite directions. The apparatus incorporates a freely swinging movable vane in the supply duct to automatically channel into the associated outlet only the deflected air flow which has the higher relative pressure.

  3. Functioning of the direct subsidies system in Poland and other European Union countries

    Directory of Open Access Journals (Sweden)

    Renata Marks-Bielska

    2010-01-01

    Full Text Available The aim of the paper was to present the functioning of the direct subsidies system in Poland. Given the profitable nature of this instrument the particular attention has been paid to the disposal of funds received by agricultural producers in the region of Warmia and Mazury in the form of subsidies. There is no doubt that the direct payments represent an important aid instrument supporting agriculture within the frameworks of the first pillar of the Common Agricultural Policy. The survey revealed that subsidies have significantly contributed to the improvement of financial condition of farms. Funds received in the form of direct payments have been mainly spent on financing current expenditures and to purchase means of production used in the farms (72.88%.

  4. Saving and gaining energy

    International Nuclear Information System (INIS)

    Lauritzen, T.

    2008-01-01

    In this interview with Dirk U. Hindrichs from the Schueco International KG company, differences between ecological and economical points of view in general are discussed, as is the world's energy consumption and the visions held by the Schueco company in this respect. The importance of building facades, windows and photovoltaics for his business is discussed, as are solar thermal systems for the production of heat and cold. Further, energy-efficiency and examples of buildings realised internationally are discussed and co-operation with important players in the climate protection area is noted. Hindrichs' opinion, that pro-active actions must be taken by entrepreneurs, is noted.

  5. Experimental analysis of direct-expansion ground-coupled heat pump systems

    Science.gov (United States)

    Mei, V. C.; Baxter, V. D.

    1991-09-01

    Direct-expansion ground-coil-coupled (DXGC) heat pump systems have certain energy efficiency advantages over conventional ground-coupled heat pump (GCHP) systems. Principal among these advantages are that the secondary heat transfer fluid heat exchanger and circulating pump are eliminated. While the DXGC concept can produce higher efficiencies, it also produces more system design and environmental problems (e.g., compressor starting, oil return, possible ground pollution, and more refrigerant charging). Furthermore, general design guidelines for DXGC systems are not well documented. A two-pronged approach was adopted for this study: (1) a literature survey, and (2) a laboratory study of a DXGC heat pump system with R-22 as the refrigerant, for both heating and cooling mode tests done in parallel and series tube connections. The results of each task are described in this paper. A set of general design guidelines was derived from the test results and is also presented.

  6. Carbon-Carbon Composites as Recuperator Materials for Direct Gas Brayton Systems

    International Nuclear Information System (INIS)

    RA Wolf

    2006-01-01

    Of the numerous energy conversion options available for a space nuclear power plant (SNPP), one that shows promise in attaining reliable operation and high efficiency is the direct gas Brayton (GB) system. In order to increase efficiency, the GB system incorporates a recuperator that accounts for nearly half the weight of the energy conversion system (ECS). Therefore, development of a recuperator that is lighter and provides better performance than current heat exchangers could prove to be advantageous. The feasibility of a carbon-carbon (C/C) composite recuperator core has been assessed and a mass savings of 60% and volume penalty of 20% were projected. The excellent thermal properties, high-temperature capabilities, and low density of carbon-carbon materials make them attractive in the GB system, but development issues such as material compatibility with other structural materials in the system, such as refractory metals and superalloys, permeability, corrosion, joining, and fabrication must be addressed

  7. Machine Directional Register System Modeling for Shaft-Less Drive Gravure Printing Machines

    Directory of Open Access Journals (Sweden)

    Shanhui Liu

    2013-01-01

    Full Text Available In the latest type of gravure printing machines referred to as the shaft-less drive system, each gravure printing roller is driven by an individual servo motor, and all motors are electrically synchronized. The register error is regulated by a speed difference between the adjacent printing rollers. In order to improve the control accuracy of register system, an accurate mathematical model of the register system should be investigated for the latest machines. Therefore, the mathematical model of the machine directional register (MDR system is studied for the multicolor gravure printing machines in this paper. According to the definition of the MDR error, the model is derived, and then it is validated by the numerical simulation and experiments carried out in the experimental setup of the four-color gravure printing machines. The results show that the established MDR system model is accurate and reliable.

  8. Carbon-Carbon Composites as Recuperator Material for Direct Gas Brayton Systems

    Energy Technology Data Exchange (ETDEWEB)

    RA Wolf

    2006-07-19

    Of the numerous energy conversion options available for a space nuclear power plant (SNPP), one that shows promise in attaining reliable operation and high efficiency is the direct gas Brayton (GB) system. In order to increase efficiency, the GB system incorporates a recuperator that accounts for nearly half the weight of the energy conversion system (ECS). Therefore, development of a recuperator that is lighter and provides better performance than current heat exchangers could prove to be advantageous. The feasibility of a carbon-carbon (C/C) composite recuperator core has been assessed and a mass savings of 60% and volume penalty of 20% were projected. The excellent thermal properties, high-temperature capabilities, and low density of carbon-carbon materials make them attractive in the GB system, but development issues such as material compatibility with other structural materials in the system, such as refractory metals and superalloys, permeability, corrosion, joining, and fabrication must be addressed.

  9. Feedback Loop Gains and Feedback Behavior (1996)

    DEFF Research Database (Denmark)

    Kampmann, Christian Erik

    2012-01-01

    Linking feedback loops and system behavior is part of the foundation of system dynamics, yet the lack of formal tools has so far prevented a systematic application of the concept, except for very simple systems. Having such tools at their disposal would be a great help to analysts in understanding...... large, complicated simulation models. The paper applies tools from graph theory formally linking individual feedback loop strengths to the system eigenvalues. The significance of a link or a loop gain and an eigenvalue can be expressed in the eigenvalue elasticity, i.e., the relative change...... of an eigenvalue resulting from a relative change in the gain. The elasticities of individual links and loops may be found through simple matrix operations on the linearized system. Even though the number of feedback loops can grow rapidly with system size, reaching astronomical proportions even for modest systems...

  10. Gaze direction effects on perceptions of upper limb kinesthetic coordinate system axes.

    Science.gov (United States)

    Darling, W G; Hondzinski, J M; Harper, J G

    2000-12-01

    The effects of varying gaze direction on perceptions of the upper limb kinesthetic coordinate system axes and of the median plane location were studied in nine subjects with no history of neuromuscular disorders. In two experiments, six subjects aligned the unseen forearm to the trunk-fixed anterior-posterior (a/p) axis and earth-fixed vertical while gazing at different visual targets using either head or eye motion to vary gaze direction in different conditions. Effects of support of the upper limb on perceptual errors were also tested in different conditions. Absolute constant errors and variable errors associated with forearm alignment to the trunk-fixed a/p axis and earth-fixed vertical were similar for different gaze directions whether the head or eyes were moved to control gaze direction. Such errors were decreased by support of the upper limb when aligning to the vertical but not when aligning to the a/p axis. Regression analysis showed that single trial errors in individual subjects were poorly correlated with gaze direction, but showed a dependence on shoulder angles for alignment to both axes. Thus, changes in position of the head and eyes do not influence perceptions of upper limb kinesthetic coordinate system axes. However, dependence of the errors on arm configuration suggests that such perceptions are generated from sensations of shoulder and elbow joint angle information. In a third experiment, perceptions of median plane location were tested by instructing four subjects to place the unseen right index fingertip directly in front of the sternum either by motion of the straight arm at the shoulder or by elbow flexion/extension with shoulder angle varied. Gaze angles were varied to the right and left by 0.5 radians to determine effects of gaze direction on such perceptions. These tasks were also carried out with subjects blind-folded and head orientation varied to test for effects of head orientation on perceptions of median plane location. Constant

  11. Direct correlation between potentiometric and impedance biosensing of antibody-antigen interactions using an integrated system

    Science.gov (United States)

    Tsai, Meng-Yen; Creedon, Niamh; Brightbill, Eleanor; Pavlidis, Spyridon; Brown, Billyde; Gray, Darren W.; Shields, Niall; Sayers, Ríona; Mooney, Mark H.; O'Riordan, Alan; Vogel, Eric M.

    2017-08-01

    A fully integrated system that combines extended gate field-effect transistor (EGFET)-based potentiometric biosensors and electrochemical impedance spectroscopy (EIS)-based biosensors has been demonstrated. This integrated configuration enables the sequential measurement of the same immunological binding event on the same sensing surface and consequently sheds light on the fundamental origins of sensing signals produced by FET and EIS biosensors, as well as the correlation between the two. Detection of both the bovine serum albumin (BSA)/anti-BSA model system in buffer solution and bovine parainfluenza antibodies in complex blood plasma samples was demonstrated using the integrated biosensors. Comparison of the EGFET and EIS sensor responses reveals similar dynamic ranges, while equivalent circuit modeling of the EIS response shows that the commonly reported total impedance change (ΔZtotal) is dominated by the change in charge transfer resistance (Rct) rather than surface capacitance (Csurface). Using electrochemical kinetics and the Butler-Volmer equation, we unveil that the surface potential and charge transfer resistance, measured by potentiometric and impedance biosensors, respectively, are, in fact, intrinsically linked. This observation suggests that there is no significant gain in using the FET/EIS integrated system and leads to the demonstration that low-cost EGFET biosensors are sufficient as a detection tool to resolve the charge information of biomolecules for practical sensing applications.

  12. Fundamental Limitations to Gain Enhancement in Periodic Media and Waveguides

    DEFF Research Database (Denmark)

    Grgic, Jure; Ott, Johan Raunkjær; Wang, Fengwen

    2012-01-01

    A common strategy to compensate for losses in optical nanostructures is to add gain material in the system. By exploiting slow-light effects it is expected that the gain may be enhanced beyond its bulk value. Here we show that this route cannot be followed uncritically: inclusion of gain inevitably...

  13. Future Direction of the Instrumentation and Control System for Security of Nuclear Facilities

    International Nuclear Information System (INIS)

    Kim, Woo Jin; Kim, Jae Kwang

    2014-01-01

    Instrumentation and control systems are pervasively used as a vital component in modern industries. Nuclear facilities, such as nuclear power plants (NPPs), originally use I and C systems for plant status monitoring, processes control, and many other purposes. After some events that raised security concerns, application areas of I and C systems have been expanded to physical protection of nuclear material and facilities. As nuclear policies over the world are strengthening security issues, the future direction of roles and technical requirements of security related I and C systems is described: An introduction of I and C systems, especially digitalized I and C systems, to security of nuclear facilities requires many careful considerations, such as system integration, verification and validation (V/V), etc. Institute of Nuclear Nonproliferation and Control (KINAC) established 'International Nuclear Nonproliferation and Security Academy, INSA' in 2014. One of the main achievements of INSA is test-bed implementation for technical criteria development of nuclear facilities' physical protection systems (PPSs) as well as for education and training of those systems. The test bed was modified and improved more suitably from the previous version to modern PPSs including state-of-the-art I and C technologies. KINAC is confident in the new test bed to become a fundamental technical basis of security related I and C systems in near future

  14. Operational gain : measuring the capture of genetic gain ...

    African Journals Online (AJOL)

    The concept of operational gain is more than the weighted average of the genetic quality of planted hectares, and encompasses tree breeding efficiencies, propagation efficiencies, matching of species and genotype to site, plant use efficiency and early measures of stand density and growth. To test the operational gain ...

  15. Neural systems analysis of decision making during goal-directed navigation.

    Science.gov (United States)

    Penner, Marsha R; Mizumori, Sheri J Y

    2012-01-01

    The ability to make adaptive decisions during goal-directed navigation is a fundamental and highly evolved behavior that requires continual coordination of perceptions, learning and memory processes, and the planning of behaviors. Here, a neurobiological account for such coordination is provided by integrating current literatures on spatial context analysis and decision-making. This integration includes discussions of our current understanding of the role of the hippocampal system in experience-dependent navigation, how hippocampal information comes to impact midbrain and striatal decision making systems, and finally the role of the striatum in the implementation of behaviors based on recent decisions. These discussions extend across cellular to neural systems levels of analysis. Not only are key findings described, but also fundamental organizing principles within and across neural systems, as well as between neural systems functions and behavior, are emphasized. It is suggested that studying decision making during goal-directed navigation is a powerful model for studying interactive brain systems and their mediation of complex behaviors. Copyright © 2011. Published by Elsevier Ltd.

  16. Induction machine Direct Torque Control system based on fuzzy adaptive control

    Science.gov (United States)

    Li, Shi-ping; Yu, Yan; Jiao, Zhen-gang; Gu, Shu-sheng

    2009-07-01

    Direct Torque Control technology is a high-performance communication control method, it uses the space voltage vector method, and then to the inverter switch state control, to obtain high torque dynamic performance. But none of the switching states is able to generate the exact voltage vector to produce the desired changes in torque and flux in most of the switching instances. This causes a high ripple in torque. To solve this problem, a fuzzy implementation of Direct Torque Control of Induction machine is presented here. Error of stator flux, error of motor electromagnetic torque and position of angle of flux are taken as fuzzy variables. In order to further solve nonlinear problem of variation parameters in direct torque control system, the paper proposes a fuzzy parameter PID adaptive control method which is suitable for the direct torque control of an asynchronous motor. The generation of its fuzzy control is obtained by analyzing and optimizing PID control step response and combining expert's experience. For this reason, it carries out fuzzy work to PID regulator of motor speed to achieve to regulate PID parameters. Therefore the control system gets swifter response velocity, stronger robustness and higher precision of velocity control. The computer simulated results verify the validity of this novel method.

  17. Hydrogen gains further momentum

    International Nuclear Information System (INIS)

    Anon.

    2017-01-01

    As first industrial production projects should become a reality in the next few years, hydrogen as a source of energy will find important applications with mobility, which momentum is rapid and irresistible. Next steps will be the (large capacity) storage of hydrogen associated to power-to-gas systems and the generalization of renewable energies. This document presents 5 articles, which themes are: Description and explanation of the process of hydrogen production; Presentation of the H2V project for the construction, in Normandy, of the first operational industrial hydrogen production plant using electric power 100 pc generated by renewable energies; The conversion of electric power from renewable energies through hydrogen storage and fuel cells for buildings applications (Sylfen project); The development of a reversible fuel cell at Mines-Paris Tech University, that will be adapted to the storage of renewable electric power; Hydrogen as a lever for the development of zero-emission vehicles, from trucks to cars and bicycles

  18. Analysis of Transient Phenomena Due to a Direct Lightning Strike on a Wind Energy System

    Directory of Open Access Journals (Sweden)

    João P. S. Catalão

    2012-07-01

    Full Text Available This paper is concerned with the protection of wind energy systems against the direct effects of lightning. As wind power generation undergoes rapid growth, lightning damages involving wind turbines have come to be regarded as a serious problem. Nevertheless, very few studies exist yet in Portugal regarding lightning protection of wind energy systems using numerical codes. A new case study is presented in this paper, based on a wind turbine with an interconnecting transformer, for the analysis of transient phenomena due to a direct lightning strike to the blade. Comprehensive simulation results are provided by using models of the Restructured Version of the Electro-Magnetic Transients Program (EMTP, and conclusions are duly drawn.

  19. Distributed Cooperative Optimal Control for Multiagent Systems on Directed Graphs: An Inverse Optimal Approach.

    Science.gov (United States)

    Zhang, Huaguang; Feng, Tao; Yang, Guang-Hong; Liang, Hongjing

    2015-07-01

    In this paper, the inverse optimal approach is employed to design distributed consensus protocols that guarantee consensus and global optimality with respect to some quadratic performance indexes for identical linear systems on a directed graph. The inverse optimal theory is developed by introducing the notion of partial stability. As a result, the necessary and sufficient conditions for inverse optimality are proposed. By means of the developed inverse optimal theory, the necessary and sufficient conditions are established for globally optimal cooperative control problems on directed graphs. Basic optimal cooperative design procedures are given based on asymptotic properties of the resulting optimal distributed consensus protocols, and the multiagent systems can reach desired consensus performance (convergence rate and damping rate) asymptotically. Finally, two examples are given to illustrate the effectiveness of the proposed methods.

  20. Analysis and hazard evaluation of heat-transfer fluids for the direct contact cooling system

    International Nuclear Information System (INIS)

    Hong, Joo Hi; Lee, Yeon Hee; Shin, You Hwan; Karng, Sarng Woo; Kim, Seo Young; Kim, Young Gil

    2006-01-01

    This paper discusses several low-temperature heat-transfer fluids, including water-based inorganic salt, organic salt, alcohol/glycol mixtures, silicones, and halogenated hydrocarbons in order to choose the best heat-transfer fluid for the newly designed direct contact refrigeration system. So, it contains a survey on commercial products such as propylene glycol and potassium formate as newly used in super market and food processing refrigeration. The stability of commercial fluids at the working temperature of -20 .deg. C was monitored as a function of time up to two months. And organic and inorganic compositions of candidate fluids were obtained by analytical instruments such as ES, XRF, AAS, ICP-AES, GC, and GC-MS. Analysis results indicate that commercial propylene glycol is very efficient and safe heat transfer fluids for the direct cooling system with liquid phase

  1. Efficiency calculations for the direct energy conversion system of the Cadarache neutral beam injectors

    International Nuclear Information System (INIS)

    White, R.C.

    1988-01-01

    A prototype energy conversion system is presently in operation at Cadarache, France. Such a device is planned for installation on each six neutral beam injectors for use in the Tore Supra experiment in 1989. We present calculations of beam performance that may influence design considerations. The calculations are performed with the DART charged particle beam code. We investigate the effects of cold plasma, direct energy conversion and neutral beam production. 4 refs., 6 figs., 4 tabs

  2. Health system tests CRM data base. Community Health Network uses direct mail to boost physicians.

    Science.gov (United States)

    Botvin, Judith D

    2003-01-01

    A six-month pilot patient retention project for Community Health Network (CHN), Indianapolis, ran from July 2002 to January 2003. It was a direct mail campaign on behalf of some members of the group practices owned by CHN, designed to test the use of the system's CRM database. Patients of the physicians received personal, dynamically-generated cards reminding them to schedule appointments and tests. Each mailing cost $1.76, including production and mailing.

  3. Energy Systems With Renewable Hydrogen Compared to Direct Use of Renewable Energy in Austria

    International Nuclear Information System (INIS)

    Gerfried Jungmeier; Kurt Konighofer; Josef Spitzer; R Haas; A Ajanovic

    2006-01-01

    The current Austrian energy system has a renewable energy share of 20% - 11% hydropower and 9 % biomass - of total primary energy consumption. Whereas a possible future introduction of renewable hydrogen must be seen in the context of current energy policies in Austria e.g. increase of energy efficiency and use of renewable energy, reduction of greenhouse gas emissions. The aim of the research project is a life cycle based comparison of energy systems with renewable hydrogen from hydropower, wind, photovoltaic and biomass compared to the direct use of renewable energy for combined heat and power applications and transportation services. In particular this paper focuses on the main question, if renewable energy should be used directly or indirectly via renewable hydrogen. The assessment is based on a life cycle approach to analyse the energy efficiency, the material demand, the greenhouse gas emissions and economic aspects e.g. energy costs and some qualitative aspects e.g. energy service. The overall comparison of the considered energy systems for transportation service and combined heat and electricity application shows, that renewable hydrogen might be beneficial mainly for transportation services, if the electric vehicle will not be further developed to a feasibly wide-spread application for transportation service in future. For combined heat and electricity production there is no advantage of renewable hydrogen versus the direct use of renewable energy. Conclusions for Austria are therefore: 1) renewable hydrogen is an interesting energy carrier and might play an important role in a future sustainable Austrian energy system; 2) renewable hydrogen applications look most promising in the transportation sector; 3) renewable hydrogen applications will be of low importance for combined heat and electricity applications, as existing technologies for direct use of renewable energy for heat and electricity are well developed and very efficient; 4) In a future '100

  4. Direct Linear System Identification Method for Multistory Three-dimensional Building Structure with General Eccentricity

    OpenAIRE

    Shintani, Kenichirou; Yoshitomi, Shinta; Takewaki, Izuru

    2017-01-01

    A method of physical parameter system identification (SI) is proposed here for three-dimensional (3D) building structures with in-plane rigid floors in which the stiffness and damping coefficients of each structural frame in the 3D building structure are identified from the measured floor horizontal accelerations. A batch processing least-squares estimation method for many discrete time domain measured data is proposed for the direct identification of the stiffness and damping coefficients of...

  5. Using Information Systems as Directions of the State Support for the Conditionally Depressive Regions

    OpenAIRE

    Morhachov Ilya V.

    2017-01-01

    The article is aimed at substantiating the perspectivity of information systems and technologies as a direction of the State support for the conditionally depressive regions. The article clarifies the assumption that an increase in the number of freelancers in region (even evaders from taxation), causes the growth of both the regional enterprises’ revenues and the tax revenues to budgets. Such freelancers become customers of works, services and goods, and, accordingly, employers for other per...

  6. A new omni-directional multi-camera system for high resolution surveillance

    Science.gov (United States)

    Cogal, Omer; Akin, Abdulkadir; Seyid, Kerem; Popovic, Vladan; Schmid, Alexandre; Ott, Beat; Wellig, Peter; Leblebici, Yusuf

    2014-05-01

    Omni-directional high resolution surveillance has a wide application range in defense and security fields. Early systems used for this purpose are based on parabolic mirror or fisheye lens where distortion due to the nature of the optical elements cannot be avoided. Moreover, in such systems, the image resolution is limited to a single image sensor's image resolution. Recently, the Panoptic camera approach that mimics the eyes of flying insects using multiple imagers has been presented. This approach features a novel solution for constructing a spherically arranged wide FOV plenoptic imaging system where the omni-directional image quality is limited by low-end sensors. In this paper, an overview of current Panoptic camera designs is provided. New results for a very-high resolution visible spectrum imaging and recording system inspired from the Panoptic approach are presented. The GigaEye-1 system, with 44 single cameras and 22 FPGAs, is capable of recording omni-directional video in a 360°×100° FOV at 9.5 fps with a resolution over (17,700×4,650) pixels (82.3MP). Real-time video capturing capability is also verified at 30 fps for a resolution over (9,000×2,400) pixels (21.6MP). The next generation system with significantly higher resolution and real-time processing capacity, called GigaEye-2, is currently under development. The important capacity of GigaEye-1 opens the door to various post-processing techniques in surveillance domain such as large perimeter object tracking, very-high resolution depth map estimation and high dynamicrange imaging which are beyond standard stitching and panorama generation methods.

  7. Current state and future direction of computer systems at NASA Langley Research Center

    Science.gov (United States)

    Rogers, James L. (Editor); Tucker, Jerry H. (Editor)

    1992-01-01

    Computer systems have advanced at a rate unmatched by any other area of technology. As performance has dramatically increased there has been an equally dramatic reduction in cost. This constant cost performance improvement has precipitated the pervasiveness of computer systems into virtually all areas of technology. This improvement is due primarily to advances in microelectronics. Most people are now convinced that the new generation of supercomputers will be built using a large number (possibly thousands) of high performance microprocessors. Although the spectacular improvements in computer systems have come about because of these hardware advances, there has also been a steady improvement in software techniques. In an effort to understand how these hardware and software advances will effect research at NASA LaRC, the Computer Systems Technical Committee drafted this white paper to examine the current state and possible future directions of computer systems at the Center. This paper discusses selected important areas of computer systems including real-time systems, embedded systems, high performance computing, distributed computing networks, data acquisition systems, artificial intelligence, and visualization.

  8. Environmental Measurement-While-Drilling System and Horizontal Directional Drilling Technology Demonstration, Hanford Site

    International Nuclear Information System (INIS)

    Williams, C.V.; Lockwood, G.J.; Normann, R.A.; Myers, D.A.; Gardner, M.G.; Williamson, T.; Huffman, J.

    1999-01-01

    The Environmental Measurement-While-Drilling (EMWD) system and Horizontal Directional Drilling (HDD) were successfully demonstrated at the Mock Tank Leak Simulation Site and the Drilling Technology Test Site, Hanford, Washington. The use of directional drilling offers an alternative to vertical drilling site characterization. Directional drilling can develop a borehole under a structure, such as a waste tank, from an angled entry and leveling off to horizontal at the desired depth. The EMWD system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drill bit data during drilling operations. The technology demonstration consisted of the development of one borehole under a mock waste tank at a depth of approximately minus8 m (minus27 ft.), following a predetermined drill path, tracking the drill path to within a radius of approximately1.5 m (5 ft.), and monitoring for zones of radiological activity using the EMWD system. The purpose of the second borehole was to demonstrate the capability of drilling to a depth of ∼ -21 m (-70 ft.), the depth needed to obtain access under the Hanford waste tanks, and continue drilling horizontally. This report presents information on the HDD and EMWD technologies, demonstration design, results of the demonstrations, and lessons learned

  9. Influence of movement direction on levitation performance and energy dissipation in a superconducting maglev system

    Directory of Open Access Journals (Sweden)

    Chen-Guang Huang

    2017-11-01

    Full Text Available During the regular operation of a maglev system, the superconducting levitation body may move away from the working position due to the external disturbance and the curved part of the guideway. Based on the A − V formulation of magnetoquasistatic Maxwell’s equations, in this paper, a two-dimensional numerical model is applied to study the influence of movement direction on a typical maglev system consisting of an infinitely long high-temperature superconductor and a guideway of two infinitely long parallel permanent magnets with opposite horizontal magnetization. After the highly nonlinear current-voltage characteristic of the superconductor is taken into account, the levitation performance change and the energy dissipation induced by the relative movement of the superconductor and the guideway are discussed. The results show that the levitation force, guidance force and power loss are strongly dependent on the movement direction and speed of the superconductor when it moves away from the working position. If the superconductor moves periodically through the working position, these three physical quantities will change periodically with time. Interestingly, the power loss drastically increases during the first cycle, and after the first cycle it starts to decrease and finally tends to a dynamic steady state. Moreover, an increase in the tilt angle of movement direction will improve the maximum levitation force and, simultaneously, enhance the energy dissipation of the maglev system.

  10. Influence of movement direction on levitation performance and energy dissipation in a superconducting maglev system

    Science.gov (United States)

    Huang, Chen-Guang; Yong, Hua-Dong; Zhou, You-He

    2017-11-01

    During the regular operation of a maglev system, the superconducting levitation body may move away from the working position due to the external disturbance and the curved part of the guideway. Based on the A - V formulation of magnetoquasistatic Maxwell's equations, in this paper, a two-dimensional numerical model is applied to study the influence of movement direction on a typical maglev system consisting of an infinitely long high-temperature superconductor and a guideway of two infinitely long parallel permanent magnets with opposite horizontal magnetization. After the highly nonlinear current-voltage characteristic of the superconductor is taken into account, the levitation performance change and the energy dissipation induced by the relative movement of the superconductor and the guideway are discussed. The results show that the levitation force, guidance force and power loss are strongly dependent on the movement direction and speed of the superconductor when it moves away from the working position. If the superconductor moves periodically through the working position, these three physical quantities will change periodically with time. Interestingly, the power loss drastically increases during the first cycle, and after the first cycle it starts to decrease and finally tends to a dynamic steady state. Moreover, an increase in the tilt angle of movement direction will improve the maximum levitation force and, simultaneously, enhance the energy dissipation of the maglev system.

  11. Effect of Room Ventilation Rates in Rodent Rooms with Direct-Exhaust IVC Systems.

    Science.gov (United States)

    Geertsema, Roger S; Lindsell, Claire E

    2015-09-01

    When IVC are directly exhausted from a rodent housing room, the air quality of the room can become independent of the intracage air quality and may reduce the need for high room ventilation rates. This study assessed the effect of decreasing the ventilation rate in rodent rooms using direct-exhaust IVC systems. The study was conducted over 16 wk and compared conditions in 8 rodent rooms that had ventilation rates of 5 to 6 air changes per hour (ACH) with those in rooms at 10 to 12 ACH. At the low ventilation rate, rooms had higher CO₂ concentrations, higher dew point temperature, and lower particulate levels and spent a greater percentage of time above the temperature set point than did rooms at the high rate. The levels of allergens and endotoxins in room air were the same regardless of the ventilation rate. Differences seen in parameters within cages at the 2 ventilation rates were operationally irrelevant. We detected no total volatile organic compounds in the room that were attributable to ammonia, regardless of the ventilation rate. Clearing the air of ethanol after a spill took longer at the low compared with high rate. However, ethanol clearance was faster at the low rate when the demand-control system was activated than at the high ventilation rate alone. Air quality in the room and in the cages were acceptable with room ventilation rates of 5 to 6 ACH in rodent rooms that use direct-exhaust IVC systems.

  12. Biomass direct-fired power generation system in China: An integrated energy, GHG emissions, and economic evaluation for Salix

    International Nuclear Information System (INIS)

    Wang, Changbo; Zhang, Lixiao; Chang, Yuan; Pang, Mingyue

    2015-01-01

    To gain a better understanding of the options of biomass power generation in China, this study presented an integrated energy, environmental, and economic evaluation for Salix in China, and a typical Salix direct-fired power generation system (SDPGS) in Inner Mongolia was selected for case study. A tiered hybrid life cycle assessment (LCA) model was developed to calculate the “planting-to-wire” (PTW) energy consumption, greenhouse gas (GHG) emissions, and economic cost and profit of the SDPGS, including feedstock cultivation, power plant construction and operation, and on-grid price with/without government subsidies. The results show that the PTW energy consumption and GHG emissions of Salix are 0.8 MJ/kWh and 114 g CO 2 -eq/kWh, respectively, indicating an energy payback time (EPBT) of 3.2 years. The SDPGS is not economically feasible without government subsidies. The PTW costs are dominated by feedstock cultivation. The energy saving and GHG mitigation benefits are still robust, even when the power plant runs at only 60% design capacity. For future development of biomass power in China, scientific planning is necessary to guarantee a sufficient feedstock supply. In addition, technology progress, mature industrial chains, and reasonable price setting policy are required to enable potential energy and environmental advantages of biomass power moving forward. -- Highlights: •A hybrid LCA model was used to evaluate overall performance of the SDPGS. •On-site processes dominate the “planting-to-wire” footprints. •The energy saving and GHG mitigation benefits of the SDPGS are robust. •The economic profit of the SDPGS is feeble without government subsidies. •Generating efficiency promotion has a comprehensive positive effect on the system

  13. Modulation classification for MIMO systems: State of the art and research directions

    International Nuclear Information System (INIS)

    Bahloul, Mohammad Rida; Yusoff, Mohd Zuki; Abdel-Aty, Abdel-Haleem; Saad, M. Naufal M.; Al-Jemeli, Marwan

    2016-01-01

    Blind techniques and algorithms for Multiple-Input Multiple-Output (MIMO) signals interception have recently attracted a great deal of research efforts. This is due to their important applications in the military and civil telecommunications domains. One essential step in the signal interception process is to blindly recognize the modulation scheme of the MIMO signals. This process is formally called Modulation Classification (MC). This paper discusses the modulation classification for MIMO systems and presents a comprehensive and critical literature review of the existing MC algorithms for MIMO systems; where possible, gaps in the knowledge base are identified and future directions for the research work are suggested.

  14. An energy management system for a directly-driven electric scooter

    International Nuclear Information System (INIS)

    Yang, Yee-Pien; Liu, Jieng-Jang; Hu, Tsung-Hsien

    2011-01-01

    An energy management system with an electronic gearshift and regenerative braking is presented to improve the gross efficiency and driving range of an electric scooter, driven directly by a four-phase axial-flux DC brushless wheel motor. The integration of stator windings, batteries, ultracapacitors, and a digital controller constitutes an energy management system, which features smooth electronic gear shifting and regenerative braking. The gross efficiency of the experimental scooter is improved in the drivable range by 20% with respect to that without regenerative braking. The battery-to-wheel efficiency was also above 70% for both low- and high-speed gears.

  15. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi; N'Doye, Ibrahima; Laleg-Kirati, Taous-Meriem

    2015-01-01

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  16. PMD compensation in fiber-optic communication systems with direct detection using LDPC-coded OFDM.

    Science.gov (United States)

    Djordjevic, Ivan B

    2007-04-02

    The possibility of polarization-mode dispersion (PMD) compensation in fiber-optic communication systems with direct detection using a simple channel estimation technique and low-density parity-check (LDPC)-coded orthogonal frequency division multiplexing (OFDM) is demonstrated. It is shown that even for differential group delay (DGD) of 4/BW (BW is the OFDM signal bandwidth), the degradation due to the first-order PMD can be completely compensated for. Two classes of LDPC codes designed based on two different combinatorial objects (difference systems and product of combinatorial designs) suitable for use in PMD compensation are introduced.

  17. Magnetohydrodynamic pump with a system for promoting flow of fluid in one direction

    Science.gov (United States)

    Lemoff, Asuncion V [Union City, CA; Lee, Abraham P [Irvine, CA

    2010-07-13

    A magnetohydrodynamic pump for pumping a fluid. The pump includes a microfluidic channel for channeling the fluid, a MHD electrode/magnet system operatively connected to the microfluidic channel, and a system for promoting flow of the fluid in one direction in the microfluidic channel. The pump has uses in the medical and biotechnology industries for blood-cell-separation equipment, biochemical assays, chemical synthesis, genetic analysis, drug screening, an array of antigen-antibody reactions, combinatorial chemistry, drug testing, medical and biological diagnostics, and combinatorial chemistry. The pump also has uses in electrochromatography, surface micromachining, laser ablation, inkjet printers, and mechanical micromilling.

  18. Development of a direct push based in-situ thermal conductivity measurement system

    Science.gov (United States)

    Chirla, Marian Andrei; Vienken, Thomas; Dietrich, Peter; Bumberger, Jan

    2016-04-01

    Heat pump systems are commonly utilized in Europe, for the exploitation of the shallow geothermal potential. To guarantee a sustainable use of the geothermal heat pump systems by saving resources and minimizing potential negative impacts induced by temperature changes within soil and groundwater, new geothermal exploration methods and tools are required. The knowledge of the underground thermal properties is a necessity for a correct and optimum design of borehole heat exchangers. The most important parameter that indicates the performance of the systems is thermal conductivity of the ground. Mapping the spatial variability of thermal conductivity, with high resolution in the shallow subsurface for geothermal purposes, requires a high degree of technical effort to procure adequate samples for thermal analysis. A collection of such samples from the soil can disturb sample structure, so great care must be taken during collection to avoid this. Factors such as transportation and sample storage can also influence measurement results. The use of technologies like Thermal Response Test (TRT) require complex mechanical and electrical systems for convective heat transport in the subsurface and longer monitoring times, often three days. Finally, by using thermal response tests, often only one integral value is obtained for the entire coupled subsurface with the borehole heat exchanger. The common thermal conductivity measurement systems (thermal analyzers) can perform vertical thermal conductivity logs only with the aid of sample procurement, or by integration into a drilling system. However, thermal conductivity measurements using direct push with this type of probes are not possible, due to physical and mechanical limitations. Applying vertical forces using direct push technology, in order to penetrate the shallow subsurface, can damage the probe and the sensors systems. The aim of this study is to develop a new, robust thermal conductivity measurement probe, for direct

  19. An energy management system for a directly-driven electric scooter

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yee-Pien, E-mail: ypyang@ntu.edu.t [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei, Taiwan (China); Liu, Jieng-Jang, E-mail: jjliu@ntu.edu.t [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei, Taiwan (China); Hu, Tsung-Hsien, E-mail: elvishu@artc.org.t [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei, Taiwan (China)

    2011-01-15

    An energy management system with an electronic gearshift and regenerative braking is presented to improve the gross efficiency and driving range of an electric scooter, driven directly by a four-phase axial-flux DC brushless wheel motor. The integration of stator windings, batteries, ultracapacitors, and a digital controller constitutes an energy management system, which features smooth electronic gear shifting and regenerative braking. The gross efficiency of the experimental scooter is improved in the drivable range by 20% with respect to that without regenerative braking. The battery-to-wheel efficiency was also above 70% for both low- and high-speed gears.

  20. An energy management system for a directly-driven electric scooter

    Energy Technology Data Exchange (ETDEWEB)

    Yee-Pien Yang; Jieng-Jang Liu; Tsung-Hsien Hu [Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Road, Section 4, Taipei (China)

    2011-01-15

    An energy management system with an electronic gearshift and regenerative braking is presented to improve the gross efficiency and driving range of an electric scooter, driven directly by a four-phase axial-flux DC brushless wheel motor. The integration of stator windings, batteries, ultracapacitors, and a digital controller constitutes an energy management system, which features smooth electronic gear shifting and regenerative braking. The gross efficiency of the experimental scooter is improved in the drivable range by 20% with respect to that without regenerative braking. The battery-to-wheel efficiency was also above 70% for both low- and high-speed gears. (author)

  1. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi

    2015-09-21

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  2. Results of a directed graph and fault tree assessment of a MC and A system

    International Nuclear Information System (INIS)

    Gilman, F.M.; Lambert, H.E.; Lim, J.J.

    1978-01-01

    An assessment of the effectiveness of the Material Control and Accounting System (MC and A) in a hypothetical nuclear facility, the TEST BED is presented. The key in assessing the TEST BED is the generation of adversary event sets. The adversary event sets are generated and analyzed by a directed graph (digraph) and fault tree procedure. Although the TEST BED is a system hardened against SNM theft, the assessment of the TEST BED finds several major weaknesses, and also indicates possible modifications to correct these weaknesses

  3. Direct calculation of self-consistent π bond orders in conjugated systems and pairing relations

    International Nuclear Information System (INIS)

    Castro, A.F.

    1982-01-01

    Pairing relations in excited states of conjugated systems which satisfy to a given symmetry with a Pariser-Parr-Pople-like (PPP) calculation are studied. Six π - electron systems are considered having a symmetry axis which does not cross π centers following a treatment which permits the direct obtainment of the bond order matrix based on Hall's method. Pairing relations are looked for, too, using particular solutions when U(3) groups is applied. Pyridazine molecules are used in order to test the results. (L.C.) [pt

  4. An Optimal Control Method for Maximizing the Efficiency of Direct Drive Ocean Wave Energy Extraction System

    Science.gov (United States)

    Chen, Zhongxian; Yu, Haitao; Wen, Cheng

    2014-01-01

    The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability. PMID:25152913

  5. Surface EEG-Transcranial Direct Current Stimulation (tDCS) Closed-Loop System.

    Science.gov (United States)

    Leite, Jorge; Morales-Quezada, Leon; Carvalho, Sandra; Thibaut, Aurore; Doruk, Deniz; Chen, Chiun-Fan; Schachter, Steven C; Rotenberg, Alexander; Fregni, Felipe

    2017-09-01

    Conventional transcranial direct current stimulation (tDCS) protocols rely on applying electrical current at a fixed intensity and duration without using surrogate markers to direct the interventions. This has led to some mixed results; especially because tDCS induced effects may vary depending on the ongoing level of brain activity. Therefore, the objective of this preliminary study was to assess the feasibility of an EEG-triggered tDCS system based on EEG online analysis of its frequency bands. Six healthy volunteers were randomized to participate in a double-blind sham-controlled crossover design to receive a single session of 10[Formula: see text]min 2[Formula: see text]mA cathodal and sham tDCS. tDCS trigger controller was based upon an algorithm designed to detect an increase in the relative beta power of more than 200%, accompanied by a decrease of 50% or more in the relative alpha power, based on baseline EEG recordings. EEG-tDCS closed-loop-system was able to detect the predefined EEG magnitude deviation and successfully triggered the stimulation in all participants. This preliminary study represents a proof-of-concept for the development of an EEG-tDCS closed-loop system in humans. We discuss and review here different methods of closed loop system that can be considered and potential clinical applications of such system.

  6. A Chaos-Based Secure Direct-Sequence/Spread-Spectrum Communication System

    Directory of Open Access Journals (Sweden)

    Nguyen Xuan Quyen

    2013-01-01

    Full Text Available This paper proposes a chaos-based secure direct-sequence/spread-spectrum (DS/SS communication system which is based on a novel combination of the conventional DS/SS and chaos techniques. In the proposed system, bit duration is varied according to a chaotic behavior but is always equal to a multiple of the fixed chip duration in the communication process. Data bits with variable duration are spectrum-spread by multiplying directly with a pseudonoise (PN sequence and then modulated onto a sinusoidal carrier by means of binary phase-shift keying (BPSK. To recover exactly the data bits, the receiver needs an identical regeneration of not only the PN sequence but also the chaotic behavior, and hence data security is improved significantly. Structure and operation of the proposed system are analyzed in detail. Theoretical evaluation of bit-error rate (BER performance in presence of additive white Gaussian noise (AWGN is provided. Parameter choice for different cases of simulation is also considered. Simulation and theoretical results are shown to verify the reliability and feasibility of the proposed system. Security of the proposed system is also discussed.

  7. An optimal control method for maximizing the efficiency of direct drive ocean wave energy extraction system.

    Science.gov (United States)

    Chen, Zhongxian; Yu, Haitao; Wen, Cheng

    2014-01-01

    The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability.

  8. Detection system qualification for direct measurement of thyroid internal contamination by radioiodine

    International Nuclear Information System (INIS)

    Tiberi, V.; Battisti, P.; Gualdrini, G.

    1999-01-01

    The work deals with a detection system qualification for direct measurements of thyroid internal contamination by radioiodine. The isotopes 131 I and 125 I are the most frequently used in nuclear medicine. Because of their volatility they are very dangerous for thyroid contamination by inhalation. The system has been projected to be easily and fast used and above all transportable where the control is necessary. These characteristic make it able to realise supervision programs of internal contamination by radioiodine. In fact due the very high control frequencies (each 15 days for 131 I), these programs are usually very expensive and demanding when they are executed in external measurement laboratories. The following steps are described: devices presentation, calculation of energy and efficiency parameters, minimum detectable activity, time system reliability, best operative conditions in the measurements. At the end an application example of the system is reported [it

  9. Research on direct calibration method of eye-to-hand system of robot

    Science.gov (United States)

    Hu, Xiaoping; Xie, Ke; Peng, Tao

    2013-10-01

    In the position-based visual servoing control for robot, the hand-eye calibration is very important because it can affect the control precision of the system. According to the robot with eye-to-hand stereovision system, this paper proposes a direct method of hand-eye calibration. The method utilizes the triangle measuring principle to solve the coordinates in the camera coordinate system of scene point. It calculates the estimated coordinates by the hand-eye calibration equation set which indicates the transformational relation from the robot to the camera coordinate system, and then uses the error of actual and estimated coordinates to establish the objective function. Finally the method substitutes the parameters into the function repeatedly until it converged to optimize the result. The related experiment compared the measured coordinates with the actual coordinates, shows the efficiency and the precision of it.

  10. Fall Prediction and Prevention Systems: Recent Trends, Challenges, and Future Research Directions

    Directory of Open Access Journals (Sweden)

    Ramesh Rajagopalan

    2017-11-01

    Full Text Available Fall prediction is a multifaceted problem that involves complex interactions between physiological, behavioral, and environmental factors. Existing fall detection and prediction systems mainly focus on physiological factors such as gait, vision, and cognition, and do not address the multifactorial nature of falls. In addition, these systems lack efficient user interfaces and feedback for preventing future falls. Recent advances in internet of things (IoT and mobile technologies offer ample opportunities for integrating contextual information about patient behavior and environment along with physiological health data for predicting falls. This article reviews the state-of-the-art in fall detection and prediction systems. It also describes the challenges, limitations, and future directions in the design and implementation of effective fall prediction and prevention systems.

  11. Direct current hopping conductance in one-dimensional diagonal disordered systems

    Institute of Scientific and Technical Information of China (English)

    Ma Song-Shan; Xu Hui; Liu Xiao-Liang; Xiao Jian-Rong

    2006-01-01

    Based on a tight-binding disordered model describing a single electron band, we establish a direct current (dc) electronic hopping transport conductance model of one-dimensional diagonal disordered systems, and also derive a dc conductance formula. By calculating the dc conductivity, the relationships between electric field and conductivity and between temperature and conductivity are analysed, and the role played by the degree of disorder in electronic transport is studied. The results indicate the conductivity of systems decreasing with the increase of the degree of disorder, characteristics of negative differential dependence of resistance on temperature at low temperatures in diagonal disordered systems, and the conductivity of systems decreasing with the increase of electric field, featuring the non-Ohm's law conductivity.

  12. A direct methanol fuel cell system to power a humanoid robot

    Science.gov (United States)

    Joh, Han-Ik; Ha, Tae Jung; Hwang, Sang Youp; Kim, Jong-Ho; Chae, Seung-Hoon; Cho, Jae Hyung; Prabhuram, Joghee; Kim, Soo-Kil; Lim, Tae-Hoon; Cho, Baek-Kyu; Oh, Jun-Ho; Moon, Sang Heup; Ha, Heung Yong

    In this study, a direct methanol fuel cell (DMFC) system, which is the first of its kind, has been developed to power a humanoid robot. The DMFC system consists of a stack, a balance of plant (BOP), a power management unit (PMU), and a back-up battery. The stack has 42 unit cells and is able to produce about 400 W at 19.3 V. The robot is 125 cm tall, weighs 56 kg, and consumes 210 W during normal operation. The robot is integrated with the DMFC system that powers the robot in a stable manner for more than 2 h. The power consumption by the robot during various motions is studied, and load sharing between the fuel cell and the back-up battery is also observed. The loss of methanol feed due to crossover and evaporation amounts to 32.0% and the efficiency of the DMFC system in terms of net electric power is 22.0%.

  13. Increasing Fuel Efficiency of Direct Methanol Fuel Cell Systems with Feedforward Control of the Operating Concentration

    Directory of Open Access Journals (Sweden)

    Youngseung Na

    2015-09-01

    Full Text Available Most of the R&D on fuel cells for portable applications concentrates on increasing efficiencies and energy densities to compete with other energy storage devices, especially batteries. To improve the efficiency of direct methanol fuel cell (DMFC systems, several modifications to system layouts and operating strategies are considered in this paper, rather than modifications to the fuel cell itself. Two modified DMFC systems are presented, one with an additional inline mixer and a further modification of it with a separate tank to recover condensed water. The set point for methanol concentration control in the solution is determined by fuel efficiency and varies with the current and other process variables. Feedforward concentration control enables variable concentration for dynamic loads. Simulation results were validated experimentally with fuel cell systems.

  14. Fall Prediction and Prevention Systems: Recent Trends, Challenges, and Future Research Directions.

    Science.gov (United States)

    Rajagopalan, Ramesh; Litvan, Irene; Jung, Tzyy-Ping

    2017-11-01

    Fall prediction is a multifaceted problem that involves complex interactions between physiological, behavioral, and environmental factors. Existing fall detection and prediction systems mainly focus on physiological factors such as gait, vision, and cognition, and do not address the multifactorial nature of falls. In addition, these systems lack efficient user interfaces and feedback for preventing future falls. Recent advances in internet of things (IoT) and mobile technologies offer ample opportunities for integrating contextual information about patient behavior and environment along with physiological health data for predicting falls. This article reviews the state-of-the-art in fall detection and prediction systems. It also describes the challenges, limitations, and future directions in the design and implementation of effective fall prediction and prevention systems.

  15. Windfall gains, political economy and economic development

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Olsson, Ola

    2008-01-01

    Natural resource rents and foreign aid have the character of windfall gains that affect economic outcomes both directly and indirectly. Several studies have shown that the indirect effect typically works via institutions like corruption. In this article, we offer a theoretical framework for a joi...... in a large cross-section of countries. Our results suggest that whereas more aid means less corruption, natural resource rents is positively correlated with corruption, although both relationships are non-linear......Natural resource rents and foreign aid have the character of windfall gains that affect economic outcomes both directly and indirectly. Several studies have shown that the indirect effect typically works via institutions like corruption. In this article, we offer a theoretical framework for a joint...

  16. High Gain Advanced GPS Receiver

    National Research Council Canada - National Science Library

    Brown, Alison; Zhang, Gengsheng

    2006-01-01

    NAVSYS High Gain Advanced GPS Receiver (HAGR) uses a digital beam-steering antenna array to enable up to eight GPS satellites to be tracked, each with up to 10 dBi of additional antenna gain over a conventional receiver solution...

  17. Simulation of a method to directly image exoplanets around multiple stars systems

    Science.gov (United States)

    Thomas, Sandrine J.; Bendek, Eduardo; Belikov, Ruslan

    2014-08-01

    Direct imaging of extra-solar planets has now become a reality, especially with the deployment and commissioning of the first generation of specialized ground-based instruments such as the GPI, SPHERE, P1640 and SCExAO. These systems will allow detection of planets 107 times fainter than their host star. For space- based missions, such as EXCEDE, EXO-C, EXO-S, WFIRST/AFTA, different teams have shown in laboratories contrasts reaching 10-10 within a few diffraction limits from the star using a combination of a coronagraph to suppress light coming from the host star and a wavefront control system. These demonstrations use a de- formable mirror (DM) to remove residual starlight (speckles) created by the imperfections of telescope. However, all these current and future systems focus on detecting faint planets around a single host star or unresolved bi- naries/multiples, while several targets or planet candidates are located around nearby binary stars such as our neighbor star Alpha Centauri. Until now, it has been thought that removing the light of a companion star is impossible with current technology, excluding binary star systems from target lists of direct imaging missions. Direct imaging around binaries/multiple systems at a level of contrast allowing Earth-like planet detection is challenging because the region of interest, where a dark zone is essential, is contaminated by the light coming from the hosts star companion. We propose a method to simultaneously correct aberrations and diffraction of light coming from the target star as well as its companion star in order to reveal planets orbiting the target star. This method works even if the companion star is outside the control region of the DM (beyond its half-Nyquist frequency), by taking advantage of aliasing effects.

  18. Bearing compartment seal systems for turbomachinery in direct-cycle HTGR power plants

    International Nuclear Information System (INIS)

    Adams, R.G.; Boenig, F.H.; Pfeifer, G.D.

    1977-10-01

    The direct-cycle High-Temperature Gas-Cooled Reactor (HTGR) employs a closed gas-turbine cycle with the primary reactor coolant (helium) as the working fluid. Design studies on this type of plant, carried out since 1971, have demonstrated, among other points, the advantages of the integrated arrangement, in which power from the cycle is transmitted to the electric generators by turbomachines completely enclosed in the reactor pressure vessel. A result of this arrangement is that the bearings are entirely enclosed within the primary coolant system of the reactor. An important aspect of the design of the turbomachinery is its prevention or minimization of the ingress of lubricants into the primary coolant system and its prevention of ingress of primary coolant into the bearing compartments. The design studies, which included thorough conceptual designs of the turbomachinery with emphasis on bearings and seals and their support systems showed that total exclusion of lubricant requires extremely complex seals and seal support systems. The variation of system low-end pressure with control actuation and the requirement that the bearing cavity pressure follow these variations were proved to further complicate the service system. The tolerance of even relatively minute amounts of entering lubricant during control transients will allow considerable simplification. This paper discusses the above-mentioned problems and their solutions in tracing the design evolution of a satisfactory bearing-compartment seals and service system. The resulting system appears to be feasible on the basis of experience with industrial gas turbines

  19. Thermoelectric characterization of an intermediate temperature solid oxide fuel cell system directly fed by dry biogas

    International Nuclear Information System (INIS)

    De Lorenzo, G.; Corigliano, O.; Lo Faro, M.; Frontera, P.; Antonucci, P.; Zignani, S.C.; Trocino, S.; Mirandola, F.A.; Aricò, A.S.; Fragiacomo, P.

    2016-01-01

    Highlights: • Numerical Model (NM) of SOFC Cogenerative System (SCS) fed by dry biogas is set up. • NM simulates new Ni-Fe/CGO protective layer for direct CH_4 consumption at the anode. • NM simulates the anode carbonation phenomenon and is experimentally validated. • The performance parameters trends of SCS fed by three types of dry biogas are shown. • SEM images after 40 h of operation show that there is no anode carbon deposition. - Abstract: A properly manufactured intermediate temperature Solid Oxide Fuel Cell (SOFC) can be directly fed by dry biogas, considering also the electrochemical partial and total oxidation reactions of methane in the biogas at the anode. In this way the methane in the biogas is electrochemically consumed directly at the fuel cell without the need to mix the biogas with any reforming gas (steam, oxygen or carbon dioxide). In this article, a numerical model of an SOFC system with Ni-Fe/CGO electrocatalyst anode protective layer directly fed by dry biogas, in cogenerative arrangement and with anode exhaust gas recirculation is formulated. The influences of biogas composition, of fuel cell operating current density and of percentage of recirculated anode exhaust gas on the SOFC system performances were evaluated by calculation code. An SOFC test bench was set up to validate the calculation code results experimentally. Furthermore, the numerical model also considers the anode carbonation and evaluates the amount of carbon that can be formed in the anode at chemical equilibrium and quasi-equilibrium conditions associated with the specific anode protective layer used.

  20. Experience gained with the development of a performance test program for the monitoring and surveillance systems in the Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Arestin, M.L.

    1988-01-01

    The monitoring and surveillance system for Embalse nuclear power plant are presented. The reactor, the nuclear fuel management, the equipments from monitoring and surveillance system, the activities developed by the AIEA experts in each mission of this test program and the management of the components for this test program in Argentine are described. (E.G.) [pt

  1. Optimization of the combustion system of a medium duty direct injection diesel engine by combining CFD modeling with experimental validation

    International Nuclear Information System (INIS)

    Benajes, Jesus; Novella, Ricardo; Pastor, Jose Manuel; Hernández-López, Alberto; Hasegawa, Manabu; Tsuji, Naohide; Emi, Masahiko; Uehara, Isshoh; Martorell, Jordi; Alonso, Marcos

    2016-01-01

    Highlights: • A DOE-based optimization of the combustion system of a CI engine has been performed. • Improving efficiency controlling emissions needs optimizing bowl design and settings. • Swirl-supported with re-entrant bowl combustion system is required after optimizing. • Computationally optimized combustion system has been validated by engine tests. - Abstract: The research in the field of internal combustion engines is currently driven by the needs of decreasing fuel consumption and CO_2 emissions, while fulfilling the increasingly stringent pollutant emissions regulations. In this framework, this research work focuses on describing a methodology for optimizing the combustion system of Compression Ignition (CI) engines, by combining Computational Fluid Dynamics (CFD) modeling, and the statistical Design of Experiments (DOE) technique known as Response Surface Method (RSM). As a key aspect, in addition to the definition of the optimum set of values for the input parameters, this methodology is extremely useful to gain knowledge on the cause/effect relationships between the input and output parameters under investigation. This methodology is applied in two sequential studies to the optimization of the combustion system of a 4-cylinder 4-stroke Medium Duty Direct Injection (DI) CI engine, minimizing the fuel consumption while fulfilling the emission limits in terms of NO_x and soot. The first study targeted four optimization parameters related to the engine hardware including piston bowl geometry, injector nozzle configuration and mean swirl number (MSN) induced by the intake manifold design. After the analysis of the results, the second study extended to six parameters, limiting the optimization of the engine hardware to the bowl geometry, but including the key air management and injection settings. For both studies, the simulation plans were defined following a Central Composite Design (CCD), providing 25 and 77 simulations respectively. The results

  2. Comparison of Direct and Indirect Gas Reactor Brayton Systems for Nuclear Electric Space Propulsion

    International Nuclear Information System (INIS)

    M Postlehwait; P DiLorenzo; S Belanger; J Ashcroft

    2005-01-01

    Gas reactor systems are being considered as candidates for use in generating power for the Prometheus-1 spacecraft, along with other NASA missions as part of the Prometheus program. Gas reactors offer a benign coolant, which increases core and structural materials options. However, the gas coolant has inferior thermal transport properties, relative to other coolant candidates such as liquid metals. This leads to concerns for providing effective heat transfer and for minimizing pressure drop within the reactor core. In direct gas Brayton systems, i.e. those with one or more Brayton turbines in the reactor cooling loop, the ability to provide effective core cooling and low pressure drop is further constrained by the need for a low pressure, high molecular weight gas, typically a mixture of helium and xenon. Use of separate primary and secondary gas loops, one for the reactor and one or more for the Brayton system(s) separated by heat exchanger(s), allows for independent optimization of the pressure and gas composition of each loop. The reactor loop can use higher pressure pure helium, which provides improved heat transfer and heat transport properties, while the Brayton loop can utilize lower pressure He-Xe. However, this approach requires a separate primary gas circulator and also requires gas to gas heat exchangers. This paper focuses on the trade-offs between the direct gas reactor Brayton system and the indirect gas Brayton system. It discusses heat exchanger arrangement and materials options and projects heat exchanger mass based on heat transfer area and structural design needs. Analysis indicates that these heat exchangers add considerable mass, but result in reactor cooling and system resiliency improvements

  3. Spectrally efficient polarization multiplexed direct-detection OFDM system without frequency gap.

    Science.gov (United States)

    Wei, Chia-Chien; Zeng, Wei-Siang; Lin, Chun-Ting

    2016-01-25

    We experimentally demonstrate a spectrally efficient direct-detection orthogonal frequency-division multiplexing (DD-OFDM) system. In addition to polarization-division multiplexing, removing the frequency gap further improves the spectral efficiency of the OFDM system. The frequency gap between a reference carrier and OFDM subcarriers avoids subcarrier-to-subcarrier beating interference (SSBI) in traditional DD-OFDM systems. Without dynamic polarization control, the resulting interference after square-law direct detection in the proposed gap-less system is polarization-dependent and composed of linear inter-carrier interference (ICI) and nonlinear SSBI. Thus, this work proposes an iterative multiple-input multiple-output detection scheme to remove the mixed polarization-dependent interference. Compared to the previous scheme, which only removes ICI, the proposed scheme can further eliminate SSBI to achieve the improvement of ∼ 7 dB in signal-to-noise ratio. Without the need for polarization control, we successfully utilize 7-GHz bandwidth to transmit a 39.5-Gbps polarization multiplexed OFDM signal over 100 km.

  4. Performance evaluation of portable HPGe with in situ object counting system (ISOCS) in direct thyroid radiobioassay

    Energy Technology Data Exchange (ETDEWEB)

    Park, Min Seok; Kwon, Tae Eun; Pak, Min Jung; Park, Se Young; Ha, Wi Ho; Jin, Young Woo [National Radiation Emergency Medical Center (NREMC), Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2016-12-15

    To evaluate the internal radiation dose, various methods are required to identify and quantify radionuclides in human body. Internal contamination monitoring related with the radioiodine is generally performed by direct radiobioassay which used scintillator-based thyroid monitor. Recently, a semiconductor material such as high purity germanium (HPGe) has been used for in vivo radiobioassay. In this study, broad energy germanium (BEGe) which was a kind of HPGe was used for thyroid radiobioassay. BEGe shows good performance in the radiobioassay due to its high energy resolution. In Situ Object Counting System (ISOCS) was the efficiency calibration software developed by Canberra Industries. The efficiency calibration with this system was performed by the Monte Carlo method. It was useful method as alternative method of conventional calibration. The purpose of this study is to evaluate the performance of measuring radioiodine by means of ISOCS which is equipped with the portable HPG(Falcon 5000, Canberra Industries) in direct thyroid radiobioassay. The ISOCS software ensured compliance with the performance criteria in the radioiodine measurement. These results of participating in intercomparison program indicated the feasibility of applying ISOCS software to direct thyroid radiobioassay with more convenient procedure.

  5. Estimation of presampling MTF in CR systems by using direct fluorescence and its problems

    International Nuclear Information System (INIS)

    Ono, Kitahei; Inatsu, Hiroshi; Harao, Mototsugu; Itonaga, Haruo; Miyamoto, Hideyuki

    2001-01-01

    We proposed a method for practical estimation of the presampling modulation transfer function (MTF) of a computed radiography (CR) system by using the MTFs of an imaging plate and the sampling aperture. The MTFs of three imaging plates (GP-25, ST-VN, and RP-1S) with different photostimulable phosphors were measured by using direct fluorescence (the light emitted instantaneously by x-ray exposure), and the presampling MTFs were estimated from these imaging plate MTFs and the sampling aperture MTF. Our results indicated that for imaging plate RP-1S the measured presampling MTF was significantly superior to the estimated presampling MTF at any spatial frequency. This was because the estimated presampling MTF was degraded by the diffusion of direct fluorescence in the protective layer of the imaging plate's surface. Therefore, when the presampling MTF of the imaging plate with a thick protective layer is estimated, correction for the thickness of the protective layer should be carried out. However, the estimated presampling MTF of imaging plates with a thin protective layer were almost the same as the measured presampling MTF, except in the high spatial frequency range. Therefore, we consider this estimation method to be useful and practical, because the spatial resolution property of a CR system can be obtained simply from the imaging plate MTF measured with direct fluorescence. (author)

  6. Voltage Balancing Method on Expert System for 51-Level MMC in High Voltage Direct Current Transmission

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2016-01-01

    Full Text Available The Modular Multilevel Converters (MMC have been a spotlight for the high voltage and high power transmission systems. In the VSC-HVDC (High Voltage Direct Current based on Voltage Source Converter transmission system, the energy of DC link is stored in the distributed capacitors, and the difference of capacitors in parameters and charge rates causes capacitor voltage balance which affects the safety and stability of HVDC system. A method of MMC based on the expert system for reducing the frequency of the submodules (SMs of the IGBT switching frequency is proposed. Firstly, MMC with 51 levels for HVDC is designed. Secondly, the nearest level control (NLC for 51-level MMC is introduced. Thirdly, a modified capacitor voltage balancing method based on expert system for MMC-based HVDC transmission system is proposed. Finally, a simulation platform for 51-level Modular Multilevel Converter is constructed by using MATLAB/SIMULINK. The results indicate that the strategy proposed reduces the switching frequency on the premise of keeping submodule voltage basically identical, which greatly reduces the power losses for MMC-HVDC system.

  7. Simulation of the Direct Digital Synthesis module for Helium RFQ LLRF system

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae-Seong; Ahn, Tae-Sung; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Song, Young-Gi; Seol, Kyung-Tae; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

    2015-10-15

    In this paper, the DDS module in the FPGA simulated and the analysis result will be introduced. Using Xilinx ISE design suite which is tool for developing the FPGA logic module, DDS module simulated. KOMAC (Korea Multi-purpose Accelerator Complex) has a plan to develop the helium irradiation system. This system includes the Ion source, LEBT, RFQ, MEBT systems to transport helium particles to the target. Especially, the RFQ (Radio Frequency Quadrupole) system should receive the 200 MHz RF within 1% amplitude error stability. For supplying stable 200 MHz RF to the RFQ, the LLRF (low-level radio frequency) should be controlled by control system. This helium RFQ LLRF control system have a concept to track the cavity resonance frequency. For tracking the cavity resonance frequency, the FPGA (Field Programmable Gate Array) in the digital board will tune the frequency of the output sinusoidal signal. In order to implement this frequency tracking concept, the DDS (Direct Digital Synthesis) module should be implemented in the FPGA. In the future, frequency tracking system will be tested using test cavity.

  8. Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

    International Nuclear Information System (INIS)

    Llamas-Guillén, S.U.; Cuevas, R.; Best, R.; Gómez, V.H.

    2014-01-01

    Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

  9. Physician medical direction and clinical performance at an established emergency medical services system.

    Science.gov (United States)

    Munk, Marc-David; White, Shaun D; Perry, Malcolm L; Platt, Thomas E; Hardan, Mohammed S; Stoy, Walt A

    2009-01-01

    Few developed emergency medical services (EMS) systems operate without dedicated medical direction. We describe the experience of Hamad Medical Corporation (HMC) EMS, which in 2007 first engaged an EMS medical director to develop and implement medical direction and quality assurance programs. We report subsequent changes to system performance over time. Over one year, changes to the service's clinical infrastructure were made: Policies were revised, paramedic scopes of practice were adjusted, evidence-based clinical protocols were developed, and skills maintenance and education programs were implemented. Credentialing, physician chart auditing, clinical remediation, and online medical command/hospital notification systems were introduced. Following these interventions, we report associated improvements to key indicators: Chart reviews revealed significant improvements in clinical quality. A comparison of pre- and post-intervention audited charts reveals a decrease in cases requiring remediation (11% to 5%, odds ratio [OR] 0.43 [95% confidence interval (CI) 0.20-0.85], p = 0.01). The proportion of charts rated as clinically acceptable rose from 48% to 84% (OR 6 [95% CI 3.9-9.1], p < 0.001). The proportion of misplaced endotracheal tubes fell (3.8% baseline to 0.6%, OR 0.16 [95% CI 0.004-1.06], (exact) p = 0.05), corresponding to improved adherence to an airway placement policy mandating use of airway confirmation devices and securing devices (0.7% compliance to 98%, OR 714 [95% CI 64-29,334], (exact) p < 0.001). Intravenous catheter insertion in unstable cases increased from 67% of cases to 92% (OR 1.31 [95% CI 1.09-1.71], p = 0.004). EMS administration of aspirin to patients with suspected ischemic chest pain improved from 2% to 77% (OR 178 [95% CI 35-1,604], p < 0.001). We suggest that implementation of a physician medical direction is associated with improved clinical indicators and overall quality of care at an established EMS system.

  10. Archive Inventory Management System (AIMS) — A Fast, Metrics Gathering Framework for Validating and Gaining Insight from Large File-Based Data Archives

    Science.gov (United States)

    Verma, R. V.

    2018-04-01

    The Archive Inventory Management System (AIMS) is a software package for understanding the distribution, characteristics, integrity, and nuances of files and directories in large file-based data archives on a continuous basis.

  11. The search for and analysis of direct samples of early Solar System aqueous fluids.

    Science.gov (United States)

    Zolensky, Michael E; Bodnar, Robert J; Yurimoto, Hisayoshi; Itoh, Shoichi; Fries, Marc; Steele, Andrew; Chan, Queenie H-S; Tsuchiyama, Akira; Kebukawa, Yoko; Ito, Motoo

    2017-05-28

    We describe the current state of the search for direct, surviving samples of early, inner Solar System fluids-fluid inclusions in meteorites. Meteoritic aqueous fluid inclusions are not rare, but they are very tiny and their characterization is at the state of the art for most analytical techniques. Meteoritic fluid inclusions offer us a unique opportunity to study early Solar System brines in the laboratory. Inclusion-by-inclusion analyses of the trapped fluids in carefully selected samples will, in the immediate future, provide us detailed information on the evolution of fluids as they interacted with anhydrous solid materials. Thus, real data can replace calculated fluid compositions in thermochemical calculations of the evolution of water and aqueous reactions in comets, asteroids, moons and the terrestrial planets.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

  12. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...... constraints in both systems. An iterative method is proposed to deal with the nonlinearity in the proposed model. The models of the natural gas and power system are linearized in every iterative step. Simulation results demonstrate the effectiveness of the approach. Applicability of the proposed method...... is tested in the sample case. Finally, the effect of Power to Gas (P2G) on the daily economic dispatch is also investigated....

  13. Direct transition from a stable equilibrium to quasiperiodicity in non-smooth systems

    DEFF Research Database (Denmark)

    Zhusubaliyev, Z.T.; Mosekilde, Erik

    2008-01-01

    The purpose of this Letter is to show how a border-collision bifurcation in a piecewise-smooth dynamical system can produce a direct transition from a stable equilibrium point to a two-dimensional invariant torus. Considering a system of nonautonomous differential equations describing the behavior...... of a power electronic DC/DC converter, we first determine the chart of dynamical modes and show that there is a region of parameter space in which the system has a single stable equilibrium point. Under variation of the parameters, this equilibrium may collide with a discontinuity boundary between two smooth...... regions in phase space. When this happens, one can observe a number of different bifurcation scenarios. One scenario is the continuous transformation of the stable equilibrium into a stable period-1 cycle. Another is the transformation of the stable equilibrium into an unstable period-1 cycle with complex...

  14. A Review of Embedded Systems Education in the Arduino Age: Lessons Learned and Future Directions

    Directory of Open Access Journals (Sweden)

    Mohammed El-Abd

    2017-06-01

    Full Text Available In this paper, the subject of embedded systems education in the Arduino age is examined. Arduino is an open-source microcontroller platform that has been widely popular in the past decade among hobbyists and academics. Arduino is increasingly being adopted in courses that span different disciplines in schools and universities. As a result, numerous papers are being published every year in different engineering education conferences and journals reporting the integration of Arduino in teaching. In this work, the impact of Arduino on embedded systems education is investigated. First, challenges facing embedded systems education are identified from the literature. Second, different Arduino teaching integration methodologies reported in the literature are surveyed and analyzed. Third, the question whether Arduino successfully addresses embedded education challenges or not is discussed taking both surveyed findings and recent market trends into consideration. Finally, a number of open-ended research directions are proposed.

  15. 120-keV beam direct conversion system for TFTR injectors

    International Nuclear Information System (INIS)

    Hamilton, G.W.

    1976-01-01

    Several practical motivations exist for the development of beam direct conversion systems that are compatible with the injection systems of large experiments such as the Tokamak Fusion Test Reactor (TFTR). We present a preliminary design in which we analyze the most acute problems involved in scaling up existing designs and apparatus to fulfill TFTR requirements. Some of the questions addressed are the requirements for electron suppression, gas pumping, compactness, and power densities. A new idea is presented that allows for the handling of higher beam power. The gross savings in the capital cost of injector power supplies for the TFTR will be about $7.2 million, but the net savings will be somewhat less than this. This preliminary design has not yet revealed fundamental limitations with respect to the development of beam energy-recovery systems operating at high levels of current, voltage, and power densities

  16. Transitions of interaction outcomes in a uni-directional consumer-resource system

    Science.gov (United States)

    Wang, Y.; DeAngelis, D.L.

    2011-01-01

    A uni-directional consumer-resource system of two species is analyzed. Our aim is to understand the mechanisms that determine how the interaction outcomes depend on the context of the interaction; that is, on the model parameters. The dynamic behavior of the model is described and, in particular, it is demonstrated that no periodic orbits exist. Then the parameter (factor) space is shown to be divided into four regions, which correspond to the four forms of interaction outcomes; i.e. mutualism, commensalism, parasitism and amensalism. It is shown that the interaction outcomes of the system transition smoothly among these four forms when the parameters of the system are varied continuously. Varying each parameter individually or varying pairs of parameters can also lead to smooth transitions between the interaction outcomes. The analysis leads to both conditions for which each species achieves its maximal density, and situations in which periodic oscillations of the interaction outcomes emerge. ?? 2011 Elsevier Ltd.

  17. On the unlimited gain of a nonlinear parametric amplifier

    DEFF Research Database (Denmark)

    Sorokin, Vladislav

    2014-01-01

    The present paper is concerned with analysis of the response of a nonlinear parametric amplifier in abroad range of system parameters, particularly beyond resonance. Such analysis is of particular interestfor micro- and nanosystems, since many small-scale parametric amplifiers exhibit a distinctly...... nonlinearbehavior when amplitude of their response is sufficiently large. The modified method of direct separa-tion of motions is employed to study the considered system. As the result it is obtained that steady-stateamplitude of the nonlinear parametric amplifier response can reach large values in the case...... of arbitrarilysmall amplitude of external excitation, so that the amplifier gain tends to infinity. Very large amplifiergain can be achieved in a broad range of system parameters, in particular when the amplitude of para-metric excitation is comparatively small. The obtained results clearly demonstrate that very...

  18. Comparison of the thermal gain of the more commonly roofing systems used in Mexico`s social dwellings; Comparacion de la ganancia termica de los sistemas de techumbre mas comunmente utilizados en la vivienda social en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Alfredo [Division de Estudios de Posgrado de la Facultad de Arquitectura UNAM, Mexico, D. F. (Mexico); Morillon, David [Comision Nacional para el Ahorro de Energia (CONAE), Mexico, D. F. (Mexico)

    1996-12-31

    Under the frame of discussion of the Mexican Official Standard 008 (Integral Energy Efficiency in non-residential Buildings), and with the purpose of assessing its feasibility and possible extension to residential buildings, this paper, whose objective is to evaluate the roofing systems (opaque) more commonly utilized on the social dwellings in Mexico, is presented. To perform this evaluation the heat gains by conduction through the roofing in different cities were obtained. Later on these heat gains were compared against the energy consumption that would produce its removal in each one of the cases. Finally, thermal resistance values (R) that allow, in significant form diminishing such gains, are presented, producing in consequence, a thermally efficient building. [Espanol] Dentro del marco de discusion de la Norma Oficial Mexicana 008 (Eficiencia energetica integral en edificios no residenciales), y con el fin de evaluar su factibilidad y posible extension hacia las edificaciones residenciales, se presenta este trabajo que tiene como objetivo la evaluacion de los sistemas de techumbre (opacos) mas comunmente utilizados dentro de la vivienda social en Mexico. Para realizar esta evaluacion se obtuvieron las ganancias por conduccion a traves del techo para distintas ciudades. Posteriormente, se compararon dichas ganancias contra el consumo de energia que produciria la remocion de las mismas en cada uno de los casos. Finalmente, se proponen valores de Resistencia Termica (R) que permitan disminuir de manera importante dichas ganancias teniendo, en consecuencia, una edificacion energeticamente eficiente.

  19. Comparison of the thermal gain of the more commonly roofing systems used in Mexico`s social dwellings; Comparacion de la ganancia termica de los sistemas de techumbre mas comunmente utilizados en la vivienda social en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Alfredo [Division de Estudios de Posgrado de la Facultad de Arquitectura UNAM, Mexico, D. F. (Mexico); Morillon, David [Comision Nacional para el Ahorro de Energia (CONAE), Mexico, D. F. (Mexico)

    1997-12-31

    Under the frame of discussion of the Mexican Official Standard 008 (Integral Energy Efficiency in non-residential Buildings), and with the purpose of assessing its feasibility and possible extension to residential buildings, this paper, whose objective is to evaluate the roofing systems (opaque) more commonly utilized on the social dwellings in Mexico, is presented. To perform this evaluation the heat gains by conduction through the roofing in different cities were obtained. Later on these heat gains were compared against the energy consumption that would produce its removal in each one of the cases. Finally, thermal resistance values (R) that allow, in significant form diminishing such gains, are presented, producing in consequence, a thermally efficient building. [Espanol] Dentro del marco de discusion de la Norma Oficial Mexicana 008 (Eficiencia energetica integral en edificios no residenciales), y con el fin de evaluar su factibilidad y posible extension hacia las edificaciones residenciales, se presenta este trabajo que tiene como objetivo la evaluacion de los sistemas de techumbre (opacos) mas comunmente utilizados dentro de la vivienda social en Mexico. Para realizar esta evaluacion se obtuvieron las ganancias por conduccion a traves del techo para distintas ciudades. Posteriormente, se compararon dichas ganancias contra el consumo de energia que produciria la remocion de las mismas en cada uno de los casos. Finalmente, se proponen valores de Resistencia Termica (R) que permitan disminuir de manera importante dichas ganancias teniendo, en consecuencia, una edificacion energeticamente eficiente.

  20. Prospective directions of information and communication systems and technologies development in logistics

    Directory of Open Access Journals (Sweden)

    E. V. Pustynnikova

    2016-01-01

    Full Text Available At present time the high trade turnover is typical of the Russian economy, which in turn, activates a sufficient intensity of goods movement. Logistics, as a goods movement path in the context of a variety of delivery methods: road, air, water, pipeline, railroad transport, including across the customs border, is acutely affected by all kinds of economic transformation. Therefore, the creation of stable conditions for movement of goods under the terms of mutually beneficial cooperation is a priority for logistics. Trends of economic development are characterized by growth of integration processes which have expressed themselves positively and proven their economic suitability. Such transformations denote the necessity of the control mechanisms improvement, including logistics. The actual issue of business processes information support in circumstances of logistical integration is considered in this article. The basis of the information system consists of information and communication resources, tools and technologies, the use of which is aimed at solving specific problems for the shaping of information infrastructure, business process reengineering, supporting economic security of business. In process of this issue studying are becoming obvious undeniable advantages of information and communication technologies use in logistics operations, the gaining of which is possible as a result of an integrated system’s interests harmonization. The article provides evidence that the market has a certain influence on the improvement of information and communication systems and technologies for complex carrying out logistical operations, which, in turn, optimizes the duration of the movement of goods and related with this process costs, thereby determines the improvement of logistic conditions in terms of business growth and competitiveness development The article provides evidence that the market has a certain influence on the improvement of information