Case Study Teaching Method Improves Student Performance and Perceptions of Learning Gains

Directory of Open Access Journals (Sweden)

Kevin M. Bonney

2015-02-01

Full Text Available Following years of widespread use in business and medical education, the case study teaching method is becoming an increasingly common teaching strategy in science education. However, the current body of research provides limited evidence that the use of published case studies effectively promotes the fulfillment of specific learning objectives integral to many biology courses. This study tested the hypothesis that case studies are more effective than classroom discussions and textbook reading at promoting learning of key biological concepts, development of written and oral communication skills, and comprehension of the relevance of biological concepts to everyday life. This study also tested the hypothesis that case studies produced by the instructor of a course are more effective at promoting learning than those produced by unaffiliated instructors. Additionally, performance on quantitative learning assessments and student perceptions of learning gains were analyzed to determine whether reported perceptions of learning gains accurately reflect academic performance. The results reported here suggest that case studies, regardless of the source, are significantly more effective than other methods of content delivery at increasing performance on examination questions related to chemical bonds, osmosis and diffusion, mitosis and meiosis, and DNA structure and replication. This finding was positively correlated to increased student perceptions of learning gains associated with oral and written communication skills and the ability to recognize connections between biological concepts and other aspects of life. Based on these findings, case studies should be considered as a preferred method for teaching about a variety of concepts in science courses.

On the performance of the noise power spectrum from the gain-corrected radiography images.

Science.gov (United States)

Kim, Dong Sik; Lee, Eunae

2018-01-01

Fixed pattern noise due to nonuniform amplifier gains and scintillator sensitivity should be alleviated in radiography imaging to acquire low-noise x-ray images from detectors. Here, the noise property of the detector is usually evaluated observing the noise power spectrum (NPS). A gain-correction scheme, in which uniformly illuminated images are averaged to design a gain map, can be applied to alleviate the fixed pattern noise problem. The normalized NPS (NNPS) of the gain-corrected image decreases as the number of images for the average increases and converges to an infimum, which can be achieved if the fixed pattern noise is completely removed. If we know the NNPS infimum of the detector, then we can determine the performance of the gain-corrected images compared with the achievable lower bound. We first construct an image-formation model considering the nonuniform gain and then consider two measurement methods based on subtraction and division to estimate the NNPS infimum of the detector. In order to obtain a high-precision NNPS infimum estimate, we consider a time-averaging method. For several flat-panel radiography detectors, we constructed the NNPS infimum measurements and compared them with NNPS values of the gain-corrected images. We observed that the NNPS values of the gain-corrected images approached the NNPS infimum as the number of images for the average increased.

Depressive symptoms and poorer performance on the Stroop Task are associated with weight gain.

Science.gov (United States)

Stinson, Emma J; Krakoff, Jonathan; Gluck, Marci E

2018-03-15

Executive function impairments and depression are associated with obesity but whether they predict weight gain is unclear. Forty-six individuals (35m, 37±10y) completed the Stroop Task, Iowa Gambling Task (IGT), Wisconsin Card Sorting Task (WCST), Inventory for Depressive Symptomatology (IDS-SR), Physical Anhedonia Scale (PAS), and Perceived Stress Scale (PSS). Body composition (DXA) and fasting glucose were also measured. Data from return visits were used to assess changes in weight. Poorer Stroop and WCST performance associated with higher BMI whereas poorer IGT and WCST performance associated with higher body fat (%; all p's≤0.05). Stroop interference (p=0.04; p=0.05) and IDS-SR (p=0.06; p=0.02) associated with increased BMI and weight gain (%/yr). In a multivariate linear model Stroop interference (β=0.40, p<0.01; β=0.35, p<0.01) and IDS-SR (β=0.38, p<0.01; β=0.37, p<0.01) independently predicted increased BMI and weight gain (%/yr) even after controlling for baseline weight and glucose levels. Poorer response inhibition and depressive symptoms, but not glucose levels, predicted weight gain. Evaluating neurocognitive and mood deficits could improve current treatment strategies for weight loss. Clinical Trial Registration Numbers NCT00523627, NCT00342732, NCT01224704. clinicaltrials.gov. Published by Elsevier Inc.

A high voltage gain quasi Z-source isolated DC/DC converter

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Blaabjerg, Frede; Loh, Poh Chiang

2014-01-01

A compact quasi-Z-source DC/DC converter is presented with high voltage gain, isolated output, and improved efficiency. The improvements in size and performance were achieved by using a square wave inverter with only two output switches driving an isolating transformer in push-pull mode, followed...... by a voltage doubling output rectifier. The converter is well-suited to applications requiring a high voltage gain, especially renewable energy sources such as photovoltaic and fuel-cell power supplies. To demonstrate the converter's performance a prototype designed to output 400 V at 500 W was constructed...

Gain uniformity experimental study performed on triple-GEM gas detector

International Nuclear Information System (INIS)

Dong Liyuan; Qi Huirong; Lu Xinyu; Ouyang Qun; Chen Yuanbo; Li Yuhong

2012-01-01

With the application of the two-dimensional GEM gaseous detector in X-ray imaging, the correction method of gain uniformity caused by triple-GEM avalanche structures and electric field uniformity should be studied. The paper reported the study of the triple-GEM detector with effective area 100 mm × 100 mm used the Pad's size of 9.5 mm × 9.5 mm. In the test, 100 readout channels were designed. Results showed that gain remained stable over time; at air flow increases, gain from increases obviously to changes very little. Particularly, triple-GEM's gain uniformity was very good (more than 80%) and the range of energy resolution was from 0.18 to 0.2. To improve gain consistency of results, the difference value revised was obtained to be about 0.1 by the least square method. It provided a better method to improve gain uniformity of GEM detector. (authors)

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.

Engine Torque Control of Spark Ignition Engine using Fuzzy Gain Scheduling

OpenAIRE

Aris Triwiyatno

2012-01-01

In the spark ignition engine system, driver convenience is very dependent on satisfying engine torque appropriate with the throttle position given by the driver. Unfortunately, sometimes the fulfillment of engine torque is not in line with fuel saving efforts. This requires the development of high performance and robust power train controllers. One way to potentially meet these performance requirements is to introduce a method of controlling engine torque using fuzzy gain scheduling. By using...

Detective quantum efficiency gains compared with speed gains for hypersensitized astronomical plates

International Nuclear Information System (INIS)

Kaye, A.L.

1977-01-01

It is reasonable to assume that gains in detective quantum efficiency (DQE) are far better criteria for assessing the performance of hypersensitizing techniques than gains in speed. It is shown here that gains in speed can be misleading, for some methods of hypersensitization give plates of increased speed but reduced detective quantum efficiency. (author)

Organizing Performance Requirements For Dynamical Systems

Science.gov (United States)

Malchow, Harvey L.; Croopnick, Steven R.

1990-01-01

Paper describes methodology for establishing performance requirements for complicated dynamical systems. Uses top-down approach. In series of steps, makes connections between high-level mission requirements and lower-level functional performance requirements. Provides systematic delineation of elements accommodating design compromises.

Incentive payments are not related to expected health gain in the pay for performance scheme for UK primary care: cross-sectional analysis

Directory of Open Access Journals (Sweden)

Fleetcroft Robert

2012-04-01

Full Text Available Abstract Background The General Medical Services primary care contract for the United Kingdom financially rewards performance in 19 clinical areas, through the Quality and Outcomes Framework. Little is known about how best to determine the size of financial incentives in pay for performance schemes. Our aim was to test the hypothesis that performance indicators with larger population health benefits receive larger financial incentives. Methods We performed cross sectional analyses to quantify associations between the size of financial incentives and expected health gain in the 2004 and 2006 versions of the Quality and Outcomes Framework. We used non-parametric two-sided Spearman rank correlation tests. Health gain was measured in expected lives saved in one year and in quality adjusted life years. For each quality indicator in an average sized general practice we tested for associations first, between the marginal increase in payment and the health gain resulting from a one percent point improvement in performance and second, between total payment and the health gain at the performance threshold for maximum payment. Results Evidence for lives saved or quality adjusted life years gained was found for 28 indicators accounting for 41% of the total incentive payments. No statistically significant associations were found between the expected health gain and incentive gained from a marginal 1% increase in performance in either the 2004 or 2006 version of the Quality and Outcomes Framework. In addition no associations were found between the size of financial payment for achievement of an indicator and the expected health gain at the performance threshold for maximum payment measured in lives saved or quality adjusted life years. Conclusions In this subgroup of indicators the financial incentives were not aligned to maximise health gain. This disconnection between incentive and expected health gain risks supporting clinical activities that are only

The effects of control-display gain on performance of race car drivers in an isometric braking task.

Science.gov (United States)

de Winter, J C F; de Groot, S

2012-12-01

To minimise lap times during car racing, it is important to build up brake forces rapidly and maintain precise control. We examined the effect of the amplification factor (gain) between brake pedal force and a visually represented output value on a driver's ability to track a target value. The test setup was a formula racing car cockpit fitted with an isometric brake pedal. Thirteen racing drivers performed tracking tasks with four control-display gains and two target functions: a step function (35 trials per gain) and a multisine function (15 trials per gain). The control-display gain had only minor effects on root mean-squared error between output value and target value, but it had large effects on build-up speed, overshoot, within-participants variability, and self-reported physical load. The results confirm the hypothesis that choosing an optimum gain involves balancing stability against physical effort.

Calculation Tool for Determining the Net Energy Gain

DEFF Research Database (Denmark)

Laustsen, Jacob Birck; Svendsen, Svend

2002-01-01

is dependent on both the U-values and the g-values. Beyond this it is dependent on the orientation of the windows and the climate and the actual period. This makes it difficult to choose the glazings and windows that are optimal with regard to energy performance in a given case. These facts have aroused a need...... for simple and accurate methods to determine and compare the energy performance of different window products. When choosing windows for new buildings or retrofitting a calculation tool that in a simple way determines the net energy gain from the specific windows in the actual building will ease the selection...... of the best window solution. Such a tool combined with a database with window products can make calculations of the heat loss or energy demand corresponding to the requirements in the new building code easier and more correct. In the paper, methods to determine energy performance data and the net energy gain...

Sinusoidal oscillators with lower gain requirements at higher frequencies based on an explicit tanh(x) nonlinearity

KAUST Repository

Elwakil, Ahmed S.

2009-04-28

Two novel sinusoidal oscillator structures with an explicit tanh(x) nonlinearity are proposed. The oscillators have the attractive feature: the higher the operating frequency, the lower the necessary gain required to start oscillations. A nonlinear model for the two oscillators is derived and verified numerically. Spice simulations using AMS BiCMOS 0.35 μ model parameters and experimental results are shown. Copyright © 2009 John Wiley & Sons, Ltd.

Cycle training induces muscle hypertrophy and strength gain: strategies and mechanisms.

Science.gov (United States)

Ozaki, Hayao; Loenneke, J P; Thiebaud, R S; Abe, T

2015-03-01

Cycle training is widely performed as a major part of any exercise program seeking to improve aerobic capacity and cardiovascular health. However, the effect of cycle training on muscle size and strength gain still requires further insight, even though it is known that professional cyclists display larger muscle size compared to controls. Therefore, the purpose of this review is to discuss the effects of cycle training on muscle size and strength of the lower extremity and the possible mechanisms for increasing muscle size with cycle training. It is plausible that cycle training requires a longer period to significantly increase muscle size compared to typical resistance training due to a much slower hypertrophy rate. Cycle training induces muscle hypertrophy similarly between young and older age groups, while strength gain seems to favor older adults, which suggests that the probability for improving in muscle quality appears to be higher in older adults compared to young adults. For young adults, higher-intensity intermittent cycling may be required to achieve strength gains. It also appears that muscle hypertrophy induced by cycle training results from the positive changes in muscle protein net balance.

Performance Analysis and Design Strategy for a Second-Order, Fixed-Gain, Position-Velocity-Measured (α-β-η-θ Tracking Filter

Directory of Open Access Journals (Sweden)

Kenshi Saho

2017-07-01

Full Text Available We present a strategy for designing an α - β - η - θ filter, a fixed-gain moving-object tracking filter using position and velocity measurements. First, performance indices and stability conditions for the filter are analytically derived. Then, an optimal gain design strategy using these results is proposed and its relationship to the position-velocity-measured (PVM Kalman filter is shown. Numerical analyses demonstrate the effectiveness of the proposed strategy, as well as a performance improvement over the traditional position-only-measured α - β filter. Moreover, we apply an α - β - η - θ filter designed using this strategy to ultra-wideband Doppler radar tracking in numerical simulations. We verify that the proposed strategy can easily design the gains for an α - β - η - θ filter based on the performance of the ultra-wideband Doppler radar and a rough approximation of the target’s acceleration. Moreover, its effectiveness in predicting the steady state performance in designing the position-velocity-measured Kalman filter is also demonstrated.

Performance analysis of selective cooperation with fixed gain relays in Nakagami-m channels

KAUST Repository

Hussain, Syed Imtiaz; Hasna, Mazen Omar; Alouini, Mohamed-Slim

2012-01-01

Selecting the best relay using the maximum signal to noise ratio (SNR) among all the relays ready to cooperate saves system resources and utilizes the available bandwidth more efficiently compared to the regular all-relay cooperation. In this paper, we analyze the performance of the best relay selection scheme with fixed gain relays operating in Nakagami-. m channels. We first derive the probability density function (PDF) of upper bounded end-to-end SNR of the relay link. Using this PDF, we derive some key performance parameters for the system including average bit error probability and average channel capacity. The analytical results are verified through Monte Carlo simulations. © 2012 Elsevier B.V.

Performance analysis of selective cooperation with fixed gain relays in Nakagami-m channels

KAUST Repository

Hussain, Syed Imtiaz

2012-09-01

Selecting the best relay using the maximum signal to noise ratio (SNR) among all the relays ready to cooperate saves system resources and utilizes the available bandwidth more efficiently compared to the regular all-relay cooperation. In this paper, we analyze the performance of the best relay selection scheme with fixed gain relays operating in Nakagami-. m channels. We first derive the probability density function (PDF) of upper bounded end-to-end SNR of the relay link. Using this PDF, we derive some key performance parameters for the system including average bit error probability and average channel capacity. The analytical results are verified through Monte Carlo simulations. © 2012 Elsevier B.V.

Priming Hand Motor Training with Repetitive Stimulation of the Fingertips; Performance Gain and Functional Imaging of Training Effects.

Science.gov (United States)

Lotze, Martin; Ladda, Aija Marie; Roschka, Sybille; Platz, Thomas; Dinse, Hubert R

Application of repetitive electrical stimulation (rES) of the fingers has been shown to improve tactile perception and sensorimotor performance in healthy individuals. To increase motor performance by priming the effects of active motor training (arm ability training; AAT) using rES. We compared the performance gain for the training increase of the averaged AAT tasks of both hands in two groups of strongly right-handed healthy volunteers. Functional Magnetic Resonance Imaging (fMRI) before and after AAT was assessed using three tasks for each hand separately: finger sequence tapping, visually guided grip force modulation, and writing. Performance during fMRI was controlled for preciseness and frequency. A total of 30 participants underwent a two-week unilateral left hand AAT, 15 participants with 20 minutes of rES priming of all fingertips of the trained hand, and 15 participants without rES priming. rES-primed AAT improved the trained left-hand performance across all training tasks on average by 32.9%, non-primed AAT improved by 29.5%. This gain in AAT performance with rES priming was predominantly driven by an increased finger tapping velocity. Functional imaging showed comparable changes for both training groups over time. Across all participants, improved AAT performance was associated with a higher contralateral primary somatosensory cortex (S1) fMRI activation magnitude during the grip force modulation task. This study highlights the importance of S1 for hand motor training gain. In addition, it suggests the usage of rES of the fingertips for priming active hand motor training. Copyright © 2016 Elsevier Inc. All rights reserved.

Developmental gains in visuospatial memory predict gains in mathematics achievement.

Directory of Open Access Journals (Sweden)

Yaoran Li

Full Text Available Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4 were larger than gains in the capacity of the central executive (d = 1.6 that in turn were larger than gains in phonological memory span (d = 1.1. First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

Developmental gains in visuospatial memory predict gains in mathematics achievement.

Science.gov (United States)

Li, Yaoran; Geary, David C

2013-01-01

Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement

Science.gov (United States)

Li, Yaoran; Geary, David C.

2013-01-01

Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning. PMID:23936154

Influence of Maturation Stage on Agility Performance Gains After Plyometric Training: A Systematic Review and Meta-analysis.

Science.gov (United States)

Asadi, Abbas; Arazi, Hamid; Ramirez-Campillo, Rodrigo; Moran, Jason; Izquierdo, Mikel

2017-09-01

Asadi, A, Arazi, H, Ramirez-Campillo, R, Moran, J, and Izquierdo, M. Influence of maturation stage on agility performance gains after plyometric training: a systematic review and meta-analysis. J Strength Cond Res 31(9): 2609-2617, 2017-Although plyometric training (PT) improves change of direction (COD) ability, the influence of age on COD gains after PT is unclear. Therefore, the aim of this systematic review was to identify the age-related pattern of improvement in COD ability after PT in youths. A computerized search within 6 databases was performed, selecting studies based on specific inclusion criteria: experimental trials published in English-language journals, PT focused on the lower-body, COD ability measurements reported before and after training, and male participants aged 10 to 18 years. Sixteen articles with a total of 30 effect sizes (ESs) in the experimental groups and 13 ESs in the control groups were included. For the analyses, subjects were categorized into 3 age groups: 10-12.9 years of age (PRE), 13-15.9 years of age (MID), and 16-18 years of age (POST). Independent of age, PT improved COD ability in youths (ES = 0.86, time gains [TG = -0.61]). However, a tendency toward greater COD ability gains was observed in older subjects (MID, ES = 0.95; POST, ES = 0.99) compared with younger subjects (PRE, ES = 0.68). Pearson product-moment correlation (r) indicated that 2-weekly sessions of PT-induced meaningful COD ability gains (for ES, r = 0.436; for TG, r = -0.624). A positive relationship was found between training intensity and ES (r = 0.493). In conclusion, PT improves COD ability in youths, with meaningfully greater effects in older youths. Two PT sessions per week, with 1,400 moderate-intensity jumps for 7 weeks, seems to be an adequate dose.

Radiation hardness of thin Low Gain Avalanche Detectors

Science.gov (United States)

Kramberger, G.; Carulla, M.; Cavallaro, E.; Cindro, V.; Flores, D.; Galloway, Z.; Grinstein, S.; Hidalgo, S.; Fadeyev, V.; Lange, J.; Mandić, I.; Medin, G.; Merlos, A.; McKinney-Martinez, F.; Mikuž, M.; Quirion, D.; Pellegrini, G.; Petek, M.; Sadrozinski, H. F.-W.; Seiden, A.; Zavrtanik, M.

2018-05-01

Low Gain Avalanche Detectors (LGAD) are based on a n++-p+-p-p++ structure where an appropriate doping of the multiplication layer (p+) leads to high enough electric fields for impact ionization. Gain factors of few tens in charge significantly improve the resolution of timing measurements, particularly for thin detectors, where the timing performance was shown to be limited by Landau fluctuations. The main obstacle for their operation is the decrease of gain with irradiation, attributed to effective acceptor removal in the gain layer. Sets of thin sensors were produced by two different producers on different substrates, with different gain layer doping profiles and thicknesses (45, 50 and 80 μm). Their performance in terms of gain/collected charge and leakage current was compared before and after irradiation with neutrons and pions up to the equivalent fluences of 5 ṡ 1015 cm-2. Transient Current Technique and charge collection measurements with LHC speed electronics were employed to characterize the detectors. The thin LGAD sensors were shown to perform much better than sensors of standard thickness (∼300 μm) and offer larger charge collection with respect to detectors without gain layer for fluences gain prolongs the beneficial performance of LGADs. Pions were found to be more damaging than neutrons at the same equivalent fluence, while no significant difference was found between different producers. At very high fluences and bias voltages the gain appears due to deep acceptors in the bulk, hence also in thin standard detectors.

A 60-dB linear VGA with novel exponential gain approximation

International Nuclear Information System (INIS)

Zhou Jiaye; Tan Xi; Wang Junyu; Tang Zhangwen; Min Hao

2009-01-01

A CMOS variable gain amplifier (VGA) that adopts a novel exponential gain approximation is presented. No additional exponential gain control circuit is required in the proposed VGA used in a direct conversion receiver. A wide gain control voltage from 0.4 to 1.8 V and a high linearity performance are achieved. The three-stage VGA with automatic gain control (AGC) and DC offset cancellation (DCOC) is fabricated in a 0.18-μm CMOS technology and shows a linear gain range of more than 58-dB with a linearity error less than ±1 dB. The 3-dB bandwidth is over 8 MHz at all gain settings. The measured input-referred third intercept point (IIP3) of the proposed VGA varies from -18.1 to 13.5 dBm, and the measured noise figure varies from 27 to 65 dB at a frequency of 1 MHz. The dynamic range of the closed-loop AGC exceeds 56 dB, where the output signal-to-noise-and-distortion ratio (SNDR) reaches 20 dB. The whole circuit, occupying 0.3 mm 2 of chip area, dissipates less than 3.7 mA from a 1.8-V supply.

Design and fabrication of an optimum peripheral region for low gain avalanche detectors

International Nuclear Information System (INIS)

Fernández-Martínez, Pablo; Flores, D.; Hidalgo, S.; Greco, V.; Merlos, A.; Pellegrini, G.; Quirion, D.

2016-01-01

Low Gain Avalanche Detectors (LGAD) represent a remarkable advance in high energy particle detection, since they provide a moderate increase (gain ~10) of the collected charge, thus leading to a notable improvement of the signal-to-noise ratio, which largely extends the possible application of Silicon detectors beyond their present working field. The optimum detection performance requires a careful implementation of the multiplication junction, in order to obtain the desired gain on the read out signal, but also a proper design of the edge termination and the peripheral region, which prevents the LGAD detectors from premature breakdown and large leakage current. This work deals with the critical technological aspects required to optimize the LGAD structure. The impact of several design strategies for the device periphery is evaluated with the aid of TCAD simulations, and compared with the experimental results obtained from the first LGAD prototypes fabricated at the IMB-CNM clean room. Solutions for the peripheral region improvement are also provided.

Design and fabrication of an optimum peripheral region for low gain avalanche detectors

Energy Technology Data Exchange (ETDEWEB)

Fernández-Martínez, Pablo; Flores, D., E-mail: david.flores@imb-cnm.csic.es; Hidalgo, S.; Greco, V.; Merlos, A.; Pellegrini, G.; Quirion, D.

2016-06-11

Low Gain Avalanche Detectors (LGAD) represent a remarkable advance in high energy particle detection, since they provide a moderate increase (gain ~10) of the collected charge, thus leading to a notable improvement of the signal-to-noise ratio, which largely extends the possible application of Silicon detectors beyond their present working field. The optimum detection performance requires a careful implementation of the multiplication junction, in order to obtain the desired gain on the read out signal, but also a proper design of the edge termination and the peripheral region, which prevents the LGAD detectors from premature breakdown and large leakage current. This work deals with the critical technological aspects required to optimize the LGAD structure. The impact of several design strategies for the device periphery is evaluated with the aid of TCAD simulations, and compared with the experimental results obtained from the first LGAD prototypes fabricated at the IMB-CNM clean room. Solutions for the peripheral region improvement are also provided.

Neutron gain for converging guide tubes

International Nuclear Information System (INIS)

Mildner, D.F.R.

1982-01-01

The method of acceptance diagrams is used to obtain analytical expressions for the neutron gain of a one-dimensional converging guide tube. It is found that the results are more easily expressed by analyzing the acceptance diagram at the exit of the funnel. The results are compared with those for the straight guide. When both guides have the same dimensions at the guide exit, the converging guide has higher transmitted intensity but with greater divergence of the beam. This analytical method is useful to assess the performance of a converging guide, though numerical computations may be required for detailed analysis of a guide system. (orig.)

High-gain capsule design for the HIDIF project

International Nuclear Information System (INIS)

Honrubia, J.J.; Cerrada, J.A.; Gomez, R.

2000-01-01

A high-gain capsule has been designed for the HIDIF project. The goal has been to relax the accelerator requirements by using a radiation pulse with lower peak temperature (220 eV) than previous designs (260 eV). The ablator material is beryllium doped with a very low concentration (0.2 atom %) of copper. The capsule absorbs 1.3 MJ and yields, approximately, 450 MJ in I-D simulations. The effect of the opacity of the ablator on capsule performance has been studied in detail. (authors)

Low-Gain Circularly Polarized Antenna with Torus-Shaped Pattern

Science.gov (United States)

Amaro, Luis R.; Kruid, Ronald C.; Vacchione, Joseph D.; Prata, Aluizio

2012-01-01

The Juno mission to Jupiter requires an antenna with a torus-shaped antenna pattern with approximately 6 dBic gain and circular polarization over the Deep Space Network (DSN) 7-GHz transmit frequency and the 8-GHz receive frequency. Given the large distances that accumulate en-route to Jupiter and the limited power afforded by the solar-powered vehicle, this toroidal low-gain antenna requires as much gain as possible while maintaining a beam width that could facilitate a +/-10deg edge of coverage. The natural antenna that produces a toroidal antenna pattern is the dipole, but the limited approx. = 2.2 dB peak gain would be insufficient. Here a shaped variation of the standard bicone antenna is proposed that could achieve the required gains and bandwidths while maintaining a size that was not excessive. The final geometry that was settled on consisted of a corrugated, shaped bicone, which is fed by a WR112 waveguide-to-coaxial- waveguide transition. This toroidal low-gain antenna (TLGA) geometry produced the requisite gain, moderate sidelobes, and the torus-shaped antenna pattern while maintaining a very good match over the entire required frequency range. Its "horn" geometry is also low-loss and capable of handling higher powers with large margins against multipactor breakdown. The final requirement for the antenna was to link with the DSN with circular polarization. A four-layer meander-line array polarizer was implemented; an approach that was fairly well suited to the TLGA geometry. The principal development of this work was to adapt the standard linear bicone such that its aperture could be increased in order to increase the available gain of the antenna. As one increases the aperture of a standard bicone, the phase variation across the aperture begins to increase, so the larger the aperture becomes, the greater the phase variation. In order to maximize the gain from any aperture antenna, the phase should be kept as uniform as possible. Thus, as the standard

Cost-optimal levels for energy performance requirements

DEFF Research Database (Denmark)

Thomsen, Kirsten Engelund; Aggerholm, Søren; Kluttig-Erhorn, Heike

2011-01-01

The CA conducted a study on experiences and challenges for setting cost optimal levels for energy performance requirements. The results were used as input by the EU Commission in their work of establishing the Regulation on a comparative methodology framework for calculating cost optimal levels...... of minimum energy performance requirements. In addition to the summary report released in August 2011, the full detailed report on this study is now also made available, just as the EC is about to publish its proposed Regulation for MS to apply in their process to update national building requirements....

Residential building envelope heat gain and cooling energy requirements

International Nuclear Information System (INIS)

Lam, Joseph C.; Tsang, C.L.; Li, Danny H.W.; Cheung, S.O.

2005-01-01

We present the energy use situation in Hong Kong from 1979 to 2001. The primary energy requirement (PER) nearly tripled during the 23-year period, rising from 195,405 TJ to 572,684 TJ. Most of the PER was used for electricity generation, and the electricity use in residential buildings rose from 7556 TJ (2099 GWh) to 32,799 TJ (9111 GWh), an increase of 334%. Air-conditioning accounted for about 40% of the total residential sector electricity consumption. A total of 144 buildings completed in the month of June during 1992-2001 were surveyed. Energy performance of the building envelopes was investigated in terms of the overall thermal transfer value (OTTV). To develop the appropriated parameters used in OTTV calculation, long-term measured weather data such as ambient temperature (1960-2001), horizontal global solar radiation (1992-2001) and global solar radiation on vertical surfaces (1996-2001) were examined. The OTTV found varied from 27 to 44 W/m 2 with a mean value of 37.7 W/m 2 . Building energy simulation technique using DOE-2.1E was employed to determine the cooling requirements and hence electricity use for building envelope designs with different OTTVs. It was found that cooling loads and electricity use could be expressed in terms of a simple two-parameter linear regression equation involving OTTV

Performance of equal gain combining with quantized phases in rayleigh fading channels

KAUST Repository

Rizvi, Umar H.

2011-01-01

In this paper, we analyze the error probability of equal gain combining with quantized channel phase compensation for binary phase shift keying signalling over Rayleigh fading channels. The probability density and characteristic functions of the combined signal amplitude are derived and used to compute the analytic expressions for the bit error probability in dependance of the number of quantization levels L, the number of diversity branches N-R and the average received signal-to-noise ratio. The analysis is utilized to outline the trade-off between N-R and L and to compare the performance with non-coherent binary frequency shift keying and differential binary phase shift keying schemes under diversity reception. © 2011 IEEE.

Comparative performance of various smart aggregates during strength gain and damage states of concrete

International Nuclear Information System (INIS)

Saravanan, T Jothi; Balamonica, K; Priya, C Bharathi; Gopalakrishnan, N; Reddy, A Likhith

2015-01-01

Information regarding the early strength gain of fresh concrete determines the time for the removal of form work and the transfer of pre-stressing forces for pre-stressed concrete. An ultrasonic based non-destructive evaluation of early strength gain may not work for concrete in fluid and semi-solid phases. A possible alternative is a lead zirconate titanate (PZT)-based smart aggregate embedded in concrete, which can evaluate the micro-structural and rheological properties right from the fluid phase. A set of five smart aggregates embedded in a concrete cube were investigated for their suitability to evaluate electromechanical impedance (EMI) signatures. Cubes were loaded to failure and the EMI during progressive strength loss under compressive loads was studied. To show the generalized applicability of this, experimental results for the performance of typical smart aggregates on a larger specimen, namely a concrete beam, are also discussed. Different statistical metrics were examined computationally on a three peak admittance curve with a parametric variation of stiffness, damping and simple scaling. The root mean square deviation (RMSD), mean absolute percentage deviation (MAPD), cross correlation (CC) and modified cross correlation (MCC) were investigated, in addition to the rate of change of the RMSD. Variations between the reference and modified states were studied. Both stiffness and mass gains occur for the smart aggregates, resulting in an increase or decrease of frequency and amplitude peaks due to progressive C-S-H gel formation. The trend of increasing stiffness and the consequent rightward shift of the resonant peaks and decrease of damping, with the consequent upward shift of amplitudes that happens during curing and strength gain, was observed to be reversed during the application of damaging loads. (paper)

Enhancing genetic gain in the era of molecular breeding.

Science.gov (United States)

Xu, Yunbi; Li, Ping; Zou, Cheng; Lu, Yanli; Xie, Chuanxiao; Zhang, Xuecai; Prasanna, Boddupalli M; Olsen, Michael S

2017-05-17

As one of the important concepts in conventional quantitative genetics and breeding, genetic gain can be defined as the amount of increase in performance that is achieved annually through artificial selection. To develop pro ducts that meet the increasing demand of mankind, especially for food and feed, in addition to various industrial uses, breeders are challenged to enhance the potential of genetic gain continuously, at ever higher rates, while they close the gaps that remain between the yield potential in breeders' demonstration trials and the actual yield in farmers' fields. Factors affecting genetic gain include genetic variation available in breeding materials, heritability for traits of interest, selection intensity, and the time required to complete a breeding cycle. Genetic gain can be improved through enhancing the potential and closing the gaps, which has been evolving and complemented with modern breeding techniques and platforms, mainly driven by molecular and genomic tools, combined with improved agronomic practice. Several key strategies are reviewed in this article. Favorable genetic variation can be unlocked and created through molecular and genomic approaches including mutation, gene mapping and discovery, and transgene and genome editing. Estimation of heritability can be improved by refining field experiments through well-controlled and precisely assayed environmental factors or envirotyping, particularly for understanding and controlling spatial heterogeneity at the field level. Selection intensity can be significantly heightened through improvements in the scale and precision of genotyping and phenotyping. The breeding cycle time can be shortened by accelerating breeding procedures through integrated breeding approaches such as marker-assisted selection and doubled haploid development. All the strategies can be integrated with other widely used conventional approaches in breeding programs to enhance genetic gain. More transdisciplinary

EGRET Unidentified Source Radio Observations and Performance of Receiver Gain Calibration

International Nuclear Information System (INIS)

Niinuma, Kotaro; Asuma, Kuniyuki; Kuniyoshi, Masaya; Matsumura, Nobuo; Takefuji, Kazuhiro; Kida, Sumiko; Takeuchi, Akihiko; Ichikawa, Hajime; Sawano, Akihiro; Yoshimura, Naoya; Suzuki, Shigehiro; Nakamura, Ryosuke; Nakayama, Yu; Daishido, Tsuneaki

2006-01-01

Last year, we have developed the receiver gain calibration system by using Johnson-Nyquist noise, for accuracy flux measurement, because we have been starting radio identification program of transient radio sources, blazars and radio counterpart of The Energetic Gamma Ray Experiment Telescope (EGRET) unidentified γ-ray sources in Waseda Nasu Pulsar Observatory. It is shown that there are a few low correlation data between receiver gain and ambient temperature around receiver for anything troubles of receiver, because we can detect gain and ambient temperature through a day by developed system. Estimated fluctuations of daily data of steady sources decrease by removing low correlation data before analysing. As the result of our analysis by using above system, radio counterpart of EGRET identified source showed fading light-curve for a week

Development and testing of the methodology for performance requirements

International Nuclear Information System (INIS)

Rivers, J.D.

1989-01-01

The U.S. Department of Energy (DOE) is in the process of implementing a set of materials control and accountability (MC ampersand A) performance requirements. These graded requirements set a uniform level of performance for similar materials at various facilities against the threat of an insider adversary stealing special nuclear material (SNM). These requirements are phrased in terms of detecting the theft of a goal quantity of SNM within a specified time period and with a probability greater than or equal to a special value and include defense-in-depth requirements. The DOE has conducted an extensive effort over the last 2 1/2 yr to develop a practical methodology to be used in evaluating facility performance against the performance requirements specified in DOE order 5633.3. The major participants in the development process have been the Office of Safeguards and Security (OSS), Brookhaven National Laboratory, and Los Alamos National Laboratory. The process has included careful reviews of related evaluation systems, a review of the intent of the requirements in the order, and site visits to most of the major facilities in the DOE complex. As a result of this extensive effort to develop guidance for the MC ampersand A performance requirements, OSS was able to provide a practical method that will allow facilities to evaluate the performance of their safeguards systems against the performance requirements. In addition, the evaluations can be validated by the cognizant operations offices in a systematic manner

14 CFR 171.269 - Marker beacon performance requirements.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Marker beacon performance requirements. 171.269 Section 171.269 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Landing System (ISMLS) § 171.269 Marker beacon performance requirements. ISMLS marker beacon equipment...

Study of gain-coupled distributed feedback laser based on high order surface gain-coupled gratings

Science.gov (United States)

Gao, Feng; Qin, Li; Chen, Yongyi; Jia, Peng; Chen, Chao; Cheng, LiWen; Chen, Hong; Liang, Lei; Zeng, Yugang; Zhang, Xing; Wu, Hao; Ning, Yongqiang; Wang, Lijun

2018-03-01

Single-longitudinal-mode, gain-coupled distributed feedback (DFB) lasers based on high order surface gain-coupled gratings are achieved. Periodic surface metal p-contacts with insulated grooves realize gain-coupled mechanism. To enhance gain contrast in the quantum wells without the introduction of effective index-coupled effect, groove length and depth were well designed. Our devices provided a single longitudinal mode with the maximum CW output power up to 48.8 mW/facet at 971.31 nm at 250 mA without facet coating, 3dB linewidth (39 dB). Optical bistable characteristic was observed with a threshold current difference. Experimentally, devices with different cavity lengths were contrasted on power-current and spectrum characteristics. Due to easy fabrication technique and stable performance, it provides a method of fabricating practical gain-coupled distributed feedback lasers for commercial applications.

46 CFR 287.12 - Election as to nonrecognition of gain.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Election as to nonrecognition of gain. 287.12 Section... of gain. (a) Election requirements. As a prerequisite to the nonrecognition of gain on the sale or... partnership, in the partnership return of income) for the taxable year in which the gain with respect to the...

Verbal Final Exam in Introductory Biology Yields Gains in Student Content Knowledge and Longitudinal Performance

Science.gov (United States)

Luckie, Douglas B.; Rivkin, Aaron M.; Aubry, Jacob R.; Marengo, Benjamin J.; Creech, Leah R.; Sweeder, Ryan D.

2013-01-01

We studied gains in student learning over eight semesters in which an introductory biology course curriculum was changed to include optional verbal final exams (VFs). Students could opt to demonstrate their mastery of course material via structured oral exams with the professor. In a quantitative assessment of cell biology content knowledge, students who passed the VF outscored their peers on the medical assessment test (MAT), an exam built with 40 Medical College Admissions Test (MCAT) questions (66.4% [n = 160] and 62% [n = 285], respectively; p students performed better on MCAT questions in all topic categories tested; the greatest gain occurred on the topic of cellular respiration. Because the VF focused on a conceptually parallel topic, photosynthesis, there may have been authentic knowledge transfer. In longitudinal tracking studies, passing the VF also correlated with higher performance in a range of upper-level science courses, with greatest significance in physiology, biochemistry, and organic chemistry. Participation had a wide range but not equal representation in academic standing, gender, and ethnicity. Yet students nearly unanimously (92%) valued the option. Our findings suggest oral exams at the introductory level may allow instructors to assess and aid students striving to achieve higher-level learning. PMID:24006399

Scaling of neck performance requirements in side impacts

NARCIS (Netherlands)

Wismans, J.S.H.M.; Meijer, R.; Rodarius, C.; Been, B.W.

2008-01-01

Neck biofidelity performance requirements for different sized crash dummies and human body computer models are usually based on scaling of performance requirements derived for a 50th percentile body size. The objective of this study is to investigate the validity of the currently used scaling laws

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...

4D Dynamic Required Navigation Performance Final Report

Science.gov (United States)

Finkelsztein, Daniel M.; Sturdy, James L.; Alaverdi, Omeed; Hochwarth, Joachim K.

2011-01-01

New advanced four dimensional trajectory (4DT) procedures under consideration for the Next Generation Air Transportation System (NextGen) require an aircraft to precisely navigate relative to a moving reference such as another aircraft. Examples are Self-Separation for enroute operations and Interval Management for in-trail and merging operations. The current construct of Required Navigation Performance (RNP), defined for fixed-reference-frame navigation, is not sufficiently specified to be applicable to defining performance levels of such air-to-air procedures. An extension of RNP to air-to-air navigation would enable these advanced procedures to be implemented with a specified level of performance. The objective of this research effort was to propose new 4D Dynamic RNP constructs that account for the dynamic spatial and temporal nature of Interval Management and Self-Separation, develop mathematical models of the Dynamic RNP constructs, "Required Self-Separation Performance" and "Required Interval Management Performance," and to analyze the performance characteristics of these air-to-air procedures using the newly developed models. This final report summarizes the activities led by Raytheon, in collaboration with GE Aviation and SAIC, and presents the results from this research effort to expand the RNP concept to a dynamic 4D frame of reference.

Performance requirements for the single-shell tank

International Nuclear Information System (INIS)

GRENARD, C.E.

1999-01-01

This document provides performance requirements for the waste storage and waste feed delivery functions of the Single-Shell Tank (SST) System. The requirements presented here in will be used as a basis for evaluating the ability of the system to complete the single-shell tank waste feed delivery mission. They will also be used to select the technology or technologies for retrieving waste from the tanks selected for the single-shell tank waste feed delivery mission, assumed to be 241-C-102 and 241-C-104. This revision of the Performance Requirements for the SST is based on the findings of the SST Functional Analysis, and are reflected in the current System Specification for the SST System

Amalgamation of Marginal Gains (AMG) as a potential system to deliver high-quality fundamental nursing care: A qualitative analysis of interviews from high-performance AMG sports and healthcare practitioners.

Science.gov (United States)

Pentecost, Claire; Richards, David A; Frost, Julia

2017-11-28

To investigate the components of the Amalgamation of Marginal Gains (AMG) performance system to identify a set of principles that can be built into an innovative fundamental nursing care protocol. Nursing is urged to refocus on its fundamental care activities, but little evidence exists to guide practising nurses. Fundamental care is a combination of many small behaviours aimed at meeting a person's care needs. AMG is a successful system of performance management that focusses on small (or marginal) gains, and might provide a new delivery framework for fundamental nursing care. Qualitative interview study. We undertook in-depth interviews with healthcare and sports professionals experienced in AMG. We analysed data using open coding in a framework analysis, and then interrogated the data using Normalisation Process Theory (NPT). We triangulated findings with AMG literature to develop an intervention logic model. We interviewed 20 AMG practitioners. AMG processes were as follows: focusing on many details to optimise performance, identification of marginal gains using different sources, understanding current versus optimum performance, monitoring at micro and macro level and strong leadership. Elements of normalisation were as follows: whole team belief in AMG to improve performance, a collective desire for excellence using evidence-based actions, whole team engagement to identify choose and implement changes, and individual and group responsibility for monitoring performance. We have elicited the processes described by AMG innovators in health care and sport and have mapped the normalisation potential and work required to embed such a system into nursing practice. The development of our logic model based on AMG and NPT may provide a practical framework for improving fundamental nursing care and is ripe for further development and testing in clinical trials. © 2017 The Authors Journal of Clinical Nursing Published by John Wiley & Sons Ltd.

Humanoid Walking Robot: Modeling, Inverse Dynamics, and Gain Scheduling Control

Directory of Open Access Journals (Sweden)

Elvedin Kljuno

2010-01-01

Full Text Available This article presents reference-model-based control design for a 10 degree-of-freedom bipedal walking robot, using nonlinear gain scheduling. The main goal is to show concentrated mass models can be used for prediction of the required joint torques for a bipedal walking robot. Relatively complicated architecture, high DOF, and balancing requirements make the control task of these robots difficult. Although linear control techniques can be used to control bipedal robots, nonlinear control is necessary for better performance. The emphasis of this work is to show that the reference model can be a bipedal walking model with concentrated mass at the center of gravity, which removes the problems related to design of a pseudo-inverse system. Another significance of this approach is the reduced calculation requirements due to the simplified procedure of nominal joint torques calculation. Kinematic and dynamic analysis is discussed including results for joint torques and ground force necessary to implement a prescribed walking motion. This analysis is accompanied by a comparison with experimental data. An inverse plant and a tracking error linearization-based controller design approach is described. We propose a novel combination of a nonlinear gain scheduling with a concentrated mass model for the MIMO bipedal robot system.

Engineered Barrier System performance requirements systems study report. Revision 02

International Nuclear Information System (INIS)

Balady, M.A.

1997-01-01

This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken

Engineered Barrier System performance requirements systems study report. Revision 02

Energy Technology Data Exchange (ETDEWEB)

Balady, M.A.

1997-01-14

This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken.

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.''

Coherence and interlimb force control: Effects of visual gain.

Science.gov (United States)

Kang, Nyeonju; Cauraugh, James H

2018-03-06

Neural coupling across hemispheres and homologous muscles often appears during bimanual motor control. Force coupling in a specific frequency domain may indicate specific bimanual force coordination patterns. This study investigated coherence on pairs of bimanual isometric index finger force while manipulating visual gain and task asymmetry conditions. We used two visual gain conditions (low and high gain = 8 and 512 pixels/N), and created task asymmetry by manipulating coefficient ratios imposed on the left and right index finger forces (0.4:1.6; 1:1; 1.6:0.4, respectively). Unequal coefficient ratios required different contributions from each hand to the bimanual force task resulting in force asymmetry. Fourteen healthy young adults performed bimanual isometric force control at 20% of their maximal level of the summed force of both fingers. We quantified peak coherence and relative phase angle between hands at 0-4, 4-8, and 8-12 Hz, and estimated a signal-to-noise ratio of bimanual forces. The findings revealed higher peak coherence and relative phase angle at 0-4 Hz than at 4-8 and 8-12 Hz for both visual gain conditions. Further, peak coherence and relative phase angle values at 0-4 Hz were larger at the high gain than at the low gain. At the high gain, higher peak coherence at 0-4 Hz collapsed across task asymmetry conditions significantly predicted greater signal-to-noise ratio. These findings indicate that a greater level of visual information facilitates bimanual force coupling at a specific frequency range related to sensorimotor processing. Copyright © 2018 Elsevier B.V. All rights reserved.

Input data required for specific performance assessment codes

International Nuclear Information System (INIS)

Seitz, R.R.; Garcia, R.S.; Starmer, R.J.; Dicke, C.A.; Leonard, P.R.; Maheras, S.J.; Rood, A.S.; Smith, R.W.

1992-02-01

The Department of Energy's National Low-Level Waste Management Program at the Idaho National Engineering Laboratory generated this report on input data requirements for computer codes to assist States and compacts in their performance assessments. This report gives generators, developers, operators, and users some guidelines on what input data is required to satisfy 22 common performance assessment codes. Each of the codes is summarized and a matrix table is provided to allow comparison of the various input required by the codes. This report does not determine or recommend which codes are preferable

Brief periods of NREM sleep do not promote early offline gains but subsequent on-task performance in motor skill learning.

Science.gov (United States)

Maier, Jonathan G; Piosczyk, Hannah; Holz, Johannes; Landmann, Nina; Deschler, Christoph; Frase, Lukas; Kuhn, Marion; Klöppel, Stefan; Spiegelhalder, Kai; Sterr, Annette; Riemann, Dieter; Feige, Bernd; Voderholzer, Ulrich; Nissen, Christoph

2017-11-01

Sleep modulates motor learning, but its detailed impact on performance curves remains to be fully characterized. This study aimed to further determine the impact of brief daytime periods of NREM sleep on 'offline' (task discontinuation after initial training) and 'on-task' (performance within the test session) changes in motor skill performance (finger tapping task). In a mixed design (combined parallel group and repeated measures) sleep laboratory study (n=17 'active' wake vs. sleep, n=19 'passive' wake vs. sleep), performance curves were assessed prior to and after a 90min period containing either sleep, active or passive wakefulness. We observed a highly significant, but state- (that is, sleep/wake)-independent early offline gain and improved on-task performance after sleep in comparison to wakefulness. Exploratory curve fitting suggested that the observed sleep effect most likely emerged from an interaction of training-induced improvement and detrimental 'time-on-task' processes, such as fatigue. Our results indicate that brief periods of NREM sleep do not promote early offline gains but subsequent on-task performance in motor skill learning. Copyright © 2017 Elsevier Inc. All rights reserved.

Receiver Gain Modulation Circuit

Science.gov (United States)

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

2011-01-01

modulating the receiver gain using an external signal. Without the RGMC, samples of calibrated references from radiometers form an ensemble data set of the natural occurring fluctuations within a receiver. By driving the gain of an otherwise stable receiver with an external signal, the conceptual framework and generalization of the mathematics of EDA can be tested. A series of measurements was conducted to evaluate and characterize the performance of the RGMC. Test signals stepped the RGMC across its dynamic range of performance using a radiometer that sampled four noise references; analysis indicates that the RGMC successfully modulated the receiver gain with an external signal. Calibration algorithms applied to four noise references demonstrate the RGMC produced ensemble data sets of the external signal.

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.

Fuzzy gain scheduling of velocity PI controller with intelligent learning algorithm for reactor control

International Nuclear Information System (INIS)

Kim, Dong Yun

1997-02-01

In this research, we propose a fuzzy gain scheduler (FGS) with an intelligent learning algorithm for a reactor control. In the proposed algorithm, the gradient descent method is used in order to generate the rule bases of a fuzzy algorithm by learning. These rule bases are obtained by minimizing an objective function, which is called a performance cost function. The objective of the FGS with an intelligent learning algorithm is to generate adequate gains, which minimize the error of system. The proposed algorithm can reduce the time and efforts required for obtaining the fuzzy rules through the intelligent learning function. The evolutionary programming algorithm is modified and adopted as the method in order to find the optimal gains which are used as the initial gains of FGS with learning function. It is applied to reactor control of nuclear power plant (NPP), and the results are compared with those of a conventional PI controller with fixed gains. As a result, it is shown that the proposed algorithm is superior to the conventional PI controller

Thermoregulation of water foraging honeybees--balancing of endothermic activity with radiative heat gain and functional requirements.

Science.gov (United States)

Kovac, Helmut; Stabentheiner, Anton; Schmaranzer, Sigurd

2010-12-01

Foraging honeybees are subjected to considerable variations of microclimatic conditions challenging their thermoregulatory ability. Solar heat is a gain in the cold but may be a burden in the heat. We investigated the balancing of endothermic activity with radiative heat gain and physiological functions of water foraging Apis mellifera carnica honeybees in the whole range of ambient temperatures (T(a)) and solar radiation they are likely to be exposed in their natural environment in Middle Europe. The mean thorax temperature (T(th)) during foraging stays was regulated at a constantly high level (37.0-38.5 °C) in a broad range of T(a) (3-30 °C). At warmer conditions (T(a)=30-39 °C) T(th) increased to a maximal level of 45.3 °C. The endothermic temperature excess (difference of T(body)-T(a) of living and dead bees) was used to assess the endogenously generated temperature elevation as a correlate of energy turnover. Up to a T(a) of ∼30 °C bees used solar heat gain for a double purpose: to reduce energetic expenditure and to increase T(th) by about 1-3 °C to improve force production of flight muscles. At higher T(a) they exhibited cooling efforts to get rid of excess heat. A high T(th) also allowed regulation of the head temperature high enough to guarantee proper function of the bees' suction pump even at low T(a). This shortened the foraging stays and this way reduced energetic costs. With decreasing T(a) bees also reduced arrival body weight and crop loading to do both minimize costs and optimize flight performance. Copyright © 2010 Elsevier Ltd. All rights reserved.

DNA gains at 8q23.2

DEFF Research Database (Denmark)

da Silva Veiga, Luciana Caricati; Bérgamo, Nádia Aparecida; dos Reis, Patrícia Pintor

2003-01-01

Gains or amplifications involving chromosome arm 8q are one of the most recurrent chromosomal alterations in head and neck tumors. To characterize previously reported gains, we performed fluorescence in situ hybridization (FISH) using the sequences BAC RP1179E1 and 8-centromere PMJ 128 as probes....

The contribution of material control to meeting performance requirements

International Nuclear Information System (INIS)

Rivers, J.D.

1989-01-01

The U.S. Dept. of Energy (DOE) is in the process of implementing a set of performance requirements for material control and accountability (MC ampersand A). These graded requirements set a uniform level of performance for similar materials at various facilities with respect to the threat of an insider adversary stealing special nuclear material (SNM). These requirements are phrased in terms of detecting the theft of a goal quantity of SNM within a specified time period and with a probability greater than or equal to a specified value and include defense in-depth requirements

Characterization of transient gain x-ray lasers

International Nuclear Information System (INIS)

Dunn, J.; Osterheld, A.; Shlyaptsev, V.

1999-01-01

We have performed numerical simulations of the transient collisional excitation Ni-like Pd 4d → 4p J = 0 → 1 147 angstrom laser transition recently observed at Lawrence Livermore National Laboratory (LLNL). The high gain ∼35 cm results from the experiment are compared with detailed modeling simulations from the 1-D RADEX code in order to better understand the main physics issues affecting the measured gain and x-ray laser propagation along the plasma column. Simulations indicate that the transient gain lifetime associated with the short pulse pumping and refraction of the x-ray laser beam out of the gain region are the main detrimental effects. Gain lifetimes of ∼7 ps(1/e decay) are inferred from the smoothly changing gain experimental observations and are in good agreement with the simulations. Furthermore, the modeling results indicate the presence of a longer-lived but lower gain later in time associated with the transition from transient to quasi-steady state excitation

A performance requirements analysis of the SSC control system

International Nuclear Information System (INIS)

Hunt, S.M.; Low, K.

1992-01-01

This paper presents the results of analysis of the performance requirements of the Superconducting Super Collider Control System. We quantify the performance requirements of the system in terms of response time, throughput and reliability. We then examine the effect of distance and traffic patterns on control system performance and examine how these factors influence the implementation of the control network architecture and compare the proposed system against those criteria. (author)

Comparison of energy performance requirements levels

DEFF Research Database (Denmark)

Spiekman, Marleen; Thomsen, Kirsten Engelund; Rose, Jørgen

This summary report provides a synthesis of the work within the EU SAVE project ASIEPI on developing a method to compare the energy performance (EP) requirement levels among the countries of Europe. Comparing EP requirement levels constitutes a major challenge. From the comparison of for instance...... the present Dutch requirement level (EPC) of 0,8 with the present Flemish level of E80, it can easily be seen that direct comparison is not possible. The conclusions and recommendations of the study are presented in part A. These constitute the most important result of the project. Part B gives an overview...... of all other project material related to that topic, which allows to easily identify the most pertinent information. Part C lists the project partners and sponsors....

Fuzzy gain scheduling of velocity PI controller with intelligent learning algorithm for reactor control

International Nuclear Information System (INIS)

Dong Yun Kim; Poong Hyun Seong; .

1997-01-01

In this research, we propose a fuzzy gain scheduler (FGS) with an intelligent learning algorithm for a reactor control. In the proposed algorithm, the gradient descent method is used in order to generate the rule bases of a fuzzy algorithm by learning. These rule bases are obtained by minimizing an objective function, which is called a performance cost function. The objective of the FGS with an intelligent learning algorithm is to generate gains, which minimize the error of system. The proposed algorithm can reduce the time and effort required for obtaining the fuzzy rules through the intelligent learning function. It is applied to reactor control of nuclear power plant (NPP), and the results are compared with those of a conventional PI controller with fixed gains. As a result, it is shown that the proposed algorithm is superior to the conventional PI controller. (author)

14 CFR 171.321 - DME and marker beacon performance requirements.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false DME and marker beacon performance... (MLS) § 171.321 DME and marker beacon performance requirements. (a) The DME equipment must meet the..._regulations/ibr_locations.html. (b) MLS marker beacon equipment must meet the performance requirements...

14 CFR 151.53 - Performance of construction work: Labor requirements.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Performance of construction work: Labor... § 151.53 Performance of construction work: Labor requirements. A sponsor who is required to include in a... during the performance of work under the contract, to the extent necessary to determine whether the...

Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement

OpenAIRE

Li, Yaoran; Geary, David C.

2013-01-01

Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusiv...

Comparison of Video Head Impulse Test (vHIT) Gains Between Two Commercially Available Devices and by Different Gain Analytical Methods.

Science.gov (United States)

Lee, Sang Hun; Yoo, Myung Hoon; Park, Jun Woo; Kang, Byung Chul; Yang, Chan Joo; Kang, Woo Suk; Ahn, Joong Ho; Chung, Jong Woo; Park, Hong Ju

2018-06-01

To evaluate whether video head impulse test (vHIT) gains are dependent on the measuring device and method of analysis. Prospective study. vHIT was performed in 25 healthy subjects using two devices simultaneously. vHIT gains were compared between these instruments and using five different methods of comparing position and velocity gains during head movement intervals. The two devices produced different vHIT gain results with the same method of analysis. There were also significant differences in the vHIT gains measured using different analytical methods. The gain analytic method that compares the areas under the velocity curve (AUC) of the head and eye movements during head movements showed lower vHIT gains than a method that compared the peak velocities of the head and eye movements. The former method produced the vHIT gain with the smallest standard deviation among the five procedures tested in this study. vHIT gains differ in normal subjects depending on the device and method of analysis used, suggesting that it is advisable for each device to have its own normal values. Gain calculations that compare the AUC of the head and eye movements during the head movements show the smallest variance.

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

Prediction of the metabolizable energy requirements of free-range laying hens.

Science.gov (United States)

Brainer, M M A; Rabello, C B V; Santos, M J B; Lopes, C C; Ludke, J V; Silva, J H V; Lima, R A

2016-01-01

This experiment was conducted with the aim of estimating the ME requirements of free-range laying hens for maintenance, weight gain, and egg production. These experiments were performed to develop an energy requirement prediction equation by using the comparative slaughter technique and the total excreta collection method. Regression equations were used to relate the energy intake, the energy retained in the body and eggs, and the heat production of the hens. These relationships were used to determine the daily ME requirement for maintenance, the efficiency energy utilization above the requirements for maintenance, and the NE requirement for maintenance. The requirement for weight gain was estimated from the energy content of the carcass, and the diet's efficiency energy utilization was determined from the weight gain, which was measured during weekly slaughter. The requirement for egg production was estimated by considering the energy content of the eggs and the efficiency of energy deposition in the eggs. The requirement and efficiency energy utilization for maintenance were 121.8 kcal ME/(kg∙d)and 0.68, respectively. Similarly, the NE requirement for maintenance was 82.4 kcal ME/(kg∙d), and the efficiency energy utilization above maintenance was 0.61. Because the carcass body weight and energy did not increase during the trial, the weight gain could not be estimated. The requirements for egg production requirement and efficiency energy utilization for egg production were 2.48 kcal/g and 0.61, respectively. The following energy prediction equation for free-range laying hens (without weight gain) was developed: ME /(hen ∙ d) = 121.8 × W + 2.48 × EM, in which W = body weight (kg) and EM = egg mass (g/[hen ∙ d]).

26 CFR 2.1-12 - Election as to nonrecognition of gain.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Election as to nonrecognition of gain. 2.1-12... TAX (CONTINUED) MARITIME CONSTRUCTION RESERVE FUND § 2.1-12 Election as to nonrecognition of gain. (a) Election requirements. As a prerequisite to the nonrecognition of gain on the sale or loss of a vessel (or...

Maximal intended velocity training induces greater gains in bench press performance than deliberately slower half-velocity training.

Science.gov (United States)

González-Badillo, Juan José; Rodríguez-Rosell, David; Sánchez-Medina, Luis; Gorostiaga, Esteban M; Pareja-Blanco, Fernando

2014-01-01

The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m · s(-1) (∼ 60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤ 0.80 m · s(-1)). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.

Working group 4B - human intrusion: Design/performance requirements

International Nuclear Information System (INIS)

Channell, J.

1993-01-01

There is no summary of the progress made by working group 4B (Human Intrusion: Design/performance Requirements) during the Electric Power Research Institute's EPRI Workshop on the technical basis of EPA HLW Disposal Criteria, March 1993. This group was to discuss the waste disposal standard, 40 CFR Part 191, in terms of the design and performance requirements of human intrusion. Instead, because there were so few members, they combined with working group 4A and studied the three-tier approach to evaluating postclosure performance

Performance Requirements for the Double Shell Tank (DST) System

International Nuclear Information System (INIS)

SMITH, D.F.

2001-01-01

This document identifies the upper-level Double-Shell Tank (DST) System functions and bounds the associated performance requirements. The functions and requirements are provided along with supporting bases. These functions and requirements, in turn, will be incorporated into specifications for the DST System

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) ; Guidance on the scientific requirements for health claims related to physical performance

DEFF Research Database (Denmark)

Tetens, Inge

The Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked by the European Food Safety Authority (EFSA) to draft guidance on scientific requirements for health claims related to physical performance. This guidance has been drawn from scientific opinions of the NDA Panel on such health...... claims. Thus, this guidance document represents the views of the NDA Panel based on the experience gained to date with the evaluation of health claims in this area. It is not intended that the document should include an exhaustive list of beneficial effects and studies/outcome measures which...

40 CFR 158.2160 - Microbial pesticides product performance data requirements.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Microbial pesticides product... AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2160 Microbial pesticides product performance data requirements. Product performance data must be developed for...

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.

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.

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.

Triple-Notched Band CPW fed UWB Antenna with Metallic Reflector for High Gain Performance

Directory of Open Access Journals (Sweden)

K. G. Jangid

2017-10-01

Full Text Available This paper exhibits the design and performance of a coplanar waveguide (CPW fed triple notched band ultra-wide band (UWB antenna. Proposed prototype has two U-shaped slots on the patch and an inverted U slot in feed line with a metal reflector beneath the radiating element. Proposed structure renders wider impedance bandwidth extended between frequencies 2.71GHz to 12.92 GHz for VSWR 2. The utmost simulated gain of proposed antenna with reflector is close to 9.9dBi at 7.4GHz. A sharp reduction observed in the efficiency values of the proposed structure at stop bands. Perhaps, this structure proved as a useful tool for various applications in modern communication systems including UWB.

Design for logistics to gain competitive advantage

DEFF Research Database (Denmark)

Chaudhuri, Atanu; Biskoptsø, Rogvi

2015-01-01

. Considering logistical requirements in design of a product which is heavy and bulky and involves significant logistics costs enabled to firm to gain competitiveness. The exercise underscored the importance of understanding logistical requirements, freight costs and dimensional constraints early in the design...... phase which is usually neglected by start-up firms focused on the engineering driven innovativeness of the products. The processes developed along with guidelines facilitate future use which can help such firms to proactively consider logistics requirements at the design stage....

Sleeve Push Technique: A Novel Method of Space Gaining.

Science.gov (United States)

Verma, Sanjeev; Bhupali, Nameksh Raj; Gupta, Deepak Kumar; Singh, Sombir; Singh, Satinder Pal

2018-01-01

Space gaining is frequently required in orthodontics. Multiple loops were initially used for space gaining and alignment. The most common used mechanics for space gaining is the use of nickel-titanium open coil springs. The disadvantage of nickel-titanium coil spring is that they cannot be used until the arches are well aligned to receive the stiffer stainless steel wires. Therefore, a new method of gaining space during initial alignment and leveling has been developed and named as sleeve push technique (SPT). The nickel-titanium wires, i.e. 0.012 inches and 0.014 inches along with archwire sleeve (protective tubing) can be used in a modified way to gain space along with alignment. This method helps in gaining space right from day 1 of treatment. The archwire sleeve and nickel-titanium wire in this new SPT act as a mutually synergistic combination and provide the orthodontist with a completely new technique for space opening.

Sleeve push technique: A novel method of space gaining

Directory of Open Access Journals (Sweden)

Sanjeev Verma

2018-01-01

Full Text Available Space gaining is frequently required in orthodontics. Multiple loops were initially used for space gaining and alignment. The most common used mechanics for space gaining is the use of nickel–titanium open coil springs. The disadvantage of nickel–titanium coil spring is that they cannot be used until the arches are well aligned to receive the stiffer stainless steel wires. Therefore, a new method of gaining space during initial alignment and leveling has been developed and named as sleeve push technique (SPT. The nickel–titanium wires, i.e. 0.012 inches and 0.014 inches along with archwire sleeve (protective tubing can be used in a modified way to gain space along with alignment. This method helps in gaining space right from day 1 of treatment. The archwire sleeve and nickel–titanium wire in this new SPT act as a mutually synergistic combination and provide the orthodontist with a completely new technique for space opening.

Assessing students' performance in software requirements engineering education using scoring rubrics

Science.gov (United States)

Mkpojiogu, Emmanuel O. C.; Hussain, Azham

2017-10-01

The study investigates how helpful the use of scoring rubrics is, in the performance assessment of software requirements engineering students and whether its use can lead to students' performance improvement in the development of software requirements artifacts and models. Scoring rubrics were used by two instructors to assess the cognitive performance of a student in the design and development of software requirements artifacts. The study results indicate that the use of scoring rubrics is very helpful in objectively assessing the performance of software requirements or software engineering students. Furthermore, the results revealed that the use of scoring rubrics can also produce a good achievement assessments direction showing whether a student is either improving or not in a repeated or iterative assessment. In a nutshell, its use leads to the performance improvement of students. The results provided some insights for further investigation and will be beneficial to researchers, requirements engineers, system designers, developers and project managers.

Improved performance of photoconductive gain hybrid UV detector by trap state engineering of ZnO nanoparticles

Science.gov (United States)

Azadinia, M.; Fathollahi, M. R.; Mosadegh, M.; Boroumand, F. A.; Mohajerani, E.

2017-10-01

With the purpose of examining the impact of donor polymer on the performance of nanocomposite photodetectors (PDs) and to better understand the underlying physics, different wide-bandgap semiconducting polymers, poly(N-vinylcarbazole), poly(9, 9-di-n-octylfluorenyl-2, 7-diyl) , and [9,9'-dioctyl-fluorene-2,7-diyl]-copoly[diphenyl-p-tolyl-amine-4,4'-diyl] (BFE), are mixed with ZnO nanoparticles (NPs) to fabricate hybrid UV PDs. Three different polymer matrix nanocomposites were investigated that differ in the electron-trap depth in the nanocomposite and also the carrier tunneling energy at the interface. All the fabricated PDs exhibit strong photoconductive gain characteristics which can be attributed to trapped electron accumulation and band bending at the cathode interface. Experimental results show that the manipulation of the photoactive nanocomposite improves the PD properties simultaneously, namely, the external quantum efficiency (EQE, ˜104%), the maximum detectivity (D*, ˜1013 Jones), and the linear dynamic range (LDR, ˜85 dB). In addition, the gain bandwidth product of the device improves more than 50 times. Furthermore, the effect of the photogenerated carrier profile within the active layer is investigated experimentally by changing the direction of the incident light using a transparent cathode. Interestingly, under illumination through the Al cathode, faster photocurrent response, wider spectral range toward the deep UV region, and higher EQE in relatively low voltages are observed. These considerations might provide a general strategy to fabricate low-cost photoconductive PDs with a reasonably good combination of gain, response speed, LDR, and selectivity.

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.

A microprocessor-based gamma-ray spectrometer with gain stabilized single-channel analyzers

International Nuclear Information System (INIS)

Borg, P.J.; Huppert, P.; Phillips, P.L.; Waddington, P.J.

1985-01-01

The design and performance of a self-contained microprocessor-based gamma-ray spectrometer for use in geophysical measurements using nuclear techniques is described. The instrument uses single-channel analyzers which are inherently simpler and faster than the Wilkinson or successive approximation ADC. A novel technique of gain stabilization together with a simple means of energy calibration has been developed. The modular design of the equipment makes it suitable for multidetector usage, required in a number of nucleonic gauges for the quantitative measurement of chemical constituents. (orig.)

Mobile Handset Performance Evaluation Using Radiation Pattern Measurements

DEFF Research Database (Denmark)

Nielsen, Jesper Ødum; Pedersen, Gert Frølund

2006-01-01

The mean effective gain is an attractive performance measure of mobile handsets, since it incorporates both directional and polarization properties of the handset and environment. In this work the mean effective gain is computed from measured spherical radiation patterns of five different mobile...... pattern is reduced. Furthermore, the frequency dependence of the mean effective gain is investigated, and a method is proposed for reducing the required number of measurements on different frequencies....

On the Fielding of a High Gain, Shock-Ignited Target on the National Ignitiion Facility in the Near Term

International Nuclear Information System (INIS)

Perkins, L.J.; Betti, R.; Schurtz, G.P.; Craxton, R.S.; Dunne, A.M.; LaFortune, K.N.; Schmitt, A.J.; McKenty, P.W.; Bailey, D.S.; Lambert, M.A.; Ribeyre, X.; Theobald, W.R.; Strozzi, D.J.; Harding, D.R.; Casner, A.; Atzemi, S.; Erbert, G.V.; Andersen, K.S.; Murakami, M.; Comley, A.J.; Cook, R.C.; Stephens, R.B.

2010-01-01

Shock ignition, a new concept for igniting thermonuclear fuel, offers the possibility for a near-term (∼3-4 years) test of high gain inertial confinement fusion on the National Ignition Facility at less than 1MJ drive energy and without the need for new laser hardware. In shock ignition, compressed fusion fuel is separately ignited by a strong spherically converging shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, fusion energy gains of ∼60 may be achievable on NIF at laser drive energies around ∼0.5MJ. Because of the simple all-DT target design, its in-flight robustness, the potential need for only 1D SSD beam smoothing, minimal early time LPI preheat, and use of present (indirect drive) laser hardware, this target may be easier to field on NIF than a conventional (polar) direct drive hotspot ignition target. Like fast ignition, shock ignition has the potential for high fusion yields at low drive energy, but requires only a single laser with less demanding timing and spatial focusing requirements. Of course, conventional symmetry and stability constraints still apply. In this paper we present initial target performance simulations, delineate the critical issues and describe the immediate-term R and D program that must be performed in order to test the potential of a high gain shock ignition target on NIF in the near term.

29 CFR 1620.15 - Jobs requiring equal skill in performance.

Science.gov (United States)

2010-07-01

... EQUAL PAY ACT § 1620.15 Jobs requiring equal skill in performance. (a) In general. The jobs to which the equal pay standard is applicable are jobs requiring equal skill in their performance. Where the amount... another job, the equal pay standard cannot apply even though the jobs may be equal in all other respects...

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)

29 CFR 1620.16 - Jobs requiring equal effort in performance.

Science.gov (United States)

2010-07-01

..., however, that men and women are working side by side on a line assembling parts. Suppose further that one... 29 Labor 4 2010-07-01 2010-07-01 false Jobs requiring equal effort in performance. 1620.16 Section... EQUAL PAY ACT § 1620.16 Jobs requiring equal effort in performance. (a) In general. The jobs to which...

Stacked Transformer for Driver Gain and Receive Signal Splitting

Science.gov (United States)

Driscoll, Kevin R.

2013-01-01

In a high-speed signal transmission system that uses transformer coupling, there is a need to provide increased transmitted signal strength without adding active components. This invention uses additional transformers to achieve the needed gain. The prior art uses stronger drivers (which require an IC redesign and a higher power supply voltage), or the addition of another active component (which can decrease reliability, increase power consumption, reduce the beneficial effect of serializer/deserializer preemphasis or deemphasis, and/or interfere with fault containment mechanisms), or uses a different transformer winding ratio (which requires redesign of the transformer and may not be feasible with high-speed signals that require a 1:1 winding ratio). This invention achieves the required gain by connecting the secondaries of multiple transformers in series. The primaries of these transformers are currently either connected in parallel or are connected to multiple drivers. There is also a need to split a receive signal to multiple destinations with minimal signal loss. Additional transformers can achieve the split. The prior art uses impedance-matching series resistors that cause a loss of signal. Instead of causing a loss, most instantiations of this invention would actually provide gain. Multiple transformers are used instead of multiple windings on a single transformer because multiple windings on the same transformer would require a redesign of the transformer, and may not be feasible with high-speed transformers that usually require a bifilar winding with a 1:1 ratio. This invention creates the split by connecting the primaries of multiple transformers in series. The secondary of each transformer is connected to one of the intended destinations without the use of impedance-matching series resistors.

Frequency Control Performance Measurement and Requirements

Energy Technology Data Exchange (ETDEWEB)

Illian, Howard F.

2010-12-20

Frequency control is an essential requirement of reliable electric power system operations. Determination of frequency control depends on frequency measurement and the practices based on these measurements that dictate acceptable frequency management. This report chronicles the evolution of these measurements and practices. As technology progresses from analog to digital for calculation, communication, and control, the technical basis for frequency control measurement and practices to determine acceptable performance continues to improve. Before the introduction of digital computing, practices were determined largely by prior experience. In anticipation of mandatory reliability rules, practices evolved from a focus primarily on commercial and equity issues to an increased focus on reliability. This evolution is expected to continue and place increased requirements for more precise measurements and a stronger scientific basis for future frequency management practices in support of reliability.

High performance sealing - meeting nuclear and aerospace requirements

International Nuclear Information System (INIS)

Wensel, R.; Metcalfe, R.

1994-11-01

Although high performance sealing is required in many places, two industries lead all others in terms of their demand-nuclear and aerospace. The factors that govern the high reliability and integrity of seals, particularly elastomer seals, for both industries are discussed. Aerospace requirements include low structural weight and a broad range of conditions, from the cold vacuum of space to the hot, high pressures of rocket motors. It is shown, by example, how a seal can be made an integral part of a structure in order to improve performance, rather than using a conventional handbook design. Typical processes are then described for selection, specification and procurement of suitable elastomers, functional and accelerated performance testing, database development and service-life prediction. Methods for quality assurance of elastomer seals are summarized. Potentially catastrophic internal dejects are a particular problem for conventional non-destructive inspection techniques. A new method of elastodynamic testing for these is described. (author)

19 CFR 143.5 - System performance requirements.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false System performance requirements. 143.5 Section 143.5 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF... must demonstrate that his system can interface directly with the Customs computer and ensure accurate...

Evaluation of the Trade Space Between UAS Maneuver Performance and SAA System Performance Requirements

Science.gov (United States)

Jack, Devin P.; Hoffler, Keith D.; Johnson, Sally C.

2014-01-01

A need exists to safely integrate Unmanned Aircraft Systems (UAS) into the National Airspace System. Replacing manned aircraft's see-and-avoid capability in the absence of an onboard pilot is one of the key challenges associated with safe integration. Sense-and-avoid (SAA) systems will have to achieve yet-to-be-determined required separation distances for a wide range of encounters. They will also need to account for the maneuver performance of the UAS they are paired with. The work described in this paper is aimed at developing an understanding of the trade space between UAS maneuver performance and SAA system performance requirements. An assessment of current manned and unmanned aircraft performance was used to establish potential UAS performance test matrix bounds. Then, nearterm UAS integration work was used to narrow down the scope. A simulator was developed with sufficient fidelity to assess SAA system performance requirements for a wide range of encounters. The simulator generates closest-point-of-approach (CPA) data from the wide range of UAS performance models maneuvering against a single intruder with various encounter geometries. The simulator is described herein and has both a graphical user interface and batch interface to support detailed analysis of individual UAS encounters and macro analysis of a very large set of UAS and encounter models, respectively. Results from the simulator using approximate performance data from a well-known manned aircraft is presented to provide insight into the problem and as verification and validation of the simulator. Analysis of climb, descent, and level turn maneuvers to avoid a collision is presented. Noting the diversity of backgrounds in the UAS community, a description of the UAS aerodynamic and propulsive design and performance parameters is included. Initial attempts to model the results made it clear that developing maneuver performance groups is required. Discussion of the performance groups developed and how

Double-differential recording and AGC using microcontrolled variable gain ASIC.

Science.gov (United States)

Rieger, Robert; Deng, Shin-Liang

2013-01-01

Low-power wearable recording of biopotentials requires acquisition front-ends with high common-mode rejection for interference suppression and adjustable gain to provide an optimum signal range to a cascading analogue-to-digital stage. A microcontroller operated double-differential (DD) recording setup and automatic gain control circuit (AGC) are discussed which reject common-mode interference and provide tunable gain, thus compensating for imbalance and variation in electrode interface impedance. Custom-designed variable gain amplifiers (ASIC) are used as part of the recording setup. The circuit gain and balance is set by the timing of microcontroller generated clock signals. Measured results are presented which confirm that improved common-mode rejection is achieved compared to a single differential amplifier in the presence of input network imbalance. Practical measured examples further validate gain control suitable for biopotential recording and power-line rejection for wearable ECG and EMG recording. The prototype front-end consumes 318 μW including amplifiers and microcontroller.

Input data requirements for performance modelling and monitoring of photovoltaic plants

DEFF Research Database (Denmark)

Gavriluta, Anamaria Florina; Spataru, Sergiu; Sera, Dezso

2018-01-01

This work investigates the input data requirements in the context of performance modeling of thin-film photovoltaic (PV) systems. The analysis focuses on the PVWatts performance model, well suited for on-line performance monitoring of PV strings, due to its low number of parameters and high......, modelling the performance of the PV modules at high irradiances requires a dataset of only a few hundred samples in order to obtain a power estimation accuracy of ~1-2\\%....

Calculation of gas gain fluctuations in uniform fields

CERN Document Server

Schindler, H; Veenhof, R

2010-01-01

Fluctuations of the charge amplification factor (gain) are a key element for assessing the performance of gas-based particle detectors In this report we present Monte Carlo calculations of electron avalanches based on the Magboltz program In terms of a simple model extracted from the simulation an intuitive explanation for the impact of the gas mixture and the electric field on the gain spectrum is proposed.

Gains and losses in nonadditive expected utility

NARCIS (Netherlands)

Rakesh, S.; Wakker, P.P.; Machina, M.J.; Munier, B.R.

1995-01-01

This paper provides a simple approach for deriving cumulative prospect theory. The key axiom is a cumulative dominance axiom which requires that a prospect be judged more attractive if in it greater gains are more likely and greater losses are less likely. In the presence of this cumulative

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.

Design requirements and performance requirements for reactor fuel recycle manipulator systems

International Nuclear Information System (INIS)

Grundmann, J.G.

1975-01-01

The development of a new generation of remote handling devices for remote production work in support of reactor fuel recycle systems is discussed. These devices require greater mobility, speed and visual capability than remote handling systems used in research activities. An upgraded manipulator system proposed for a High-Temperature Gas-Cooled Reactor fuel refabrication facility is described. Design and performance criteria for the manipulators, cranes, and TV cameras in the proposed system are enumerated

Temporal Gain Correction for X-Ray Calorimeter Spectrometers

Science.gov (United States)

Porter, F. S.; Chiao, M. P.; Eckart, M. E.; Fujimoto, R.; Ishisaki, Y.; Kelley, R. L.; Kilbourne, C. A.; Leutenegger, M. A.; McCammon, D.; Mitsuda, K.

2016-01-01

Calorimetric X-ray detectors are very sensitive to their environment. The boundary conditions can have a profound effect on the gain including heat sink temperature, the local radiation temperature, bias, and the temperature of the readout electronics. Any variation in the boundary conditions can cause temporal variations in the gain of the detector and compromise both the energy scale and the resolving power of the spectrometer. Most production X-ray calorimeter spectrometers, both on the ground and in space, have some means of tracking the gain as a function of time, often using a calibration spectral line. For small gain changes, a linear stretch correction is often sufficient. However, the detectors are intrinsically non-linear and often the event analysis, i.e., shaping, optimal filters etc., add additional non-linearity. Thus for large gain variations or when the best possible precision is required, a linear stretch correction is not sufficient. Here, we discuss a new correction technique based on non-linear interpolation of the energy-scale functions. Using Astro-HSXS calibration data, we demonstrate that the correction can recover the X-ray energy to better than 1 part in 104 over the entire spectral band to above 12 keV even for large-scale gain variations. This method will be used to correct any temporal drift of the on-orbit per-pixel gain using on-board calibration sources for the SXS instrument on the Astro-H observatory.

Ultra-high gain diffusion-driven organic transistor

Science.gov (United States)

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-01-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal–semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics. PMID:26829567

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 ...

Competence with fractions predicts gains in mathematics achievement.

Science.gov (United States)

Bailey, Drew H; Hoard, Mary K; Nugent, Lara; Geary, David C

2012-11-01

Competence with fractions predicts later mathematics achievement, but the codevelopmental pattern between fractions knowledge and mathematics achievement is not well understood. We assessed this codevelopment through examination of the cross-lagged relation between a measure of conceptual knowledge of fractions and mathematics achievement in sixth and seventh grades (N=212). The cross-lagged effects indicated that performance on the sixth grade fractions concepts measure predicted 1-year gains in mathematics achievement (ß=.14, pmathematics achievement did not predict gains on the fractions concepts measure (ß=.03, p>.50). In a follow-up assessment, we demonstrated that measures of fluency with computational fractions significantly predicted seventh grade mathematics achievement above and beyond the influence of fluency in computational whole number arithmetic, performance on number fluency and number line tasks, central executive span, and intelligence. Results provide empirical support for the hypothesis that competence with fractions underlies, in part, subsequent gains in mathematics achievement. Copyright © 2012 Elsevier Inc. All rights reserved.

Cost optimal building performance requirements. Calculation methodology for reporting on national energy performance requirements on the basis of cost optimality within the framework of the EPBD

Energy Technology Data Exchange (ETDEWEB)

Boermans, T.; Bettgenhaeuser, K.; Hermelink, A.; Schimschar, S. [Ecofys, Utrecht (Netherlands)

2011-05-15

On the European level, the principles for the requirements for the energy performance of buildings are set by the Energy Performance of Buildings Directive (EPBD). Dating from December 2002, the EPBD has set a common framework from which the individual Member States in the EU developed or adapted their individual national regulations. The EPBD in 2008 and 2009 underwent a recast procedure, with final political agreement having been reached in November 2009. The new Directive was then formally adopted on May 19, 2010. Among other clarifications and new provisions, the EPBD recast introduces a benchmarking mechanism for national energy performance requirements for the purpose of determining cost-optimal levels to be used by Member States for comparing and setting these requirements. The previous EPBD set out a general framework to assess the energy performance of buildings and required Member States to define maximum values for energy delivered to meet the energy demand associated with the standardised use of the building. However it did not contain requirements or guidance related to the ambition level of such requirements. As a consequence, building regulations in the various Member States have been developed by the use of different approaches (influenced by different building traditions, political processes and individual market conditions) and resulted in different ambition levels where in many cases cost optimality principles could justify higher ambitions. The EPBD recast now requests that Member States shall ensure that minimum energy performance requirements for buildings are set 'with a view to achieving cost-optimal levels'. The cost optimum level shall be calculated in accordance with a comparative methodology. The objective of this report is to contribute to the ongoing discussion in Europe around the details of such a methodology by describing possible details on how to calculate cost optimal levels and pointing towards important factors and

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.)

42 CFR 456.245 - Number of studies required to be performed.

Science.gov (United States)

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Number of studies required to be performed. 456.245 Section 456.245 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... Ur Plan: Medical Care Evaluation Studies § 456.245 Number of studies required to be performed. The...

42 CFR 456.145 - Number of studies required to be performed.

Science.gov (United States)

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Number of studies required to be performed. 456.145 Section 456.145 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...: Medical Care Evaluation Studies § 456.145 Number of studies required to be performed. The hospital must...

Composição do ganho e exigências de energia e proteína para ganho de peso em bovinos Nelore puros e mestiços Gain composition and net energy and protein requirements for weight gain in Nellore and crossbred cattle

Directory of Open Access Journals (Sweden)

José Antônio de Freitas

2006-06-01

Full Text Available Objetivou-se estimar a composição do ganho e as exigências de energia e proteína para ganho de peso em bovinos Nelore puros e mestiços. Utilizaram-se 60 bovinos machos (Nelore, F1 Nelore x Angus, F1 Nelore x Pardo-Suíço e F1 Nelore x Simental não-castrados, com 10 a 11 meses de idade e peso médio inicial de 286, 309, 333 e 310 kg, respectivamente. O delineamento utilizado foi o inteiramente casualizado, com quatro grupos genéticos, submetidos a quatro níveis de concentrado na ração (30, 40, 60 e 70%. Três animais de cada grupo genético foram abatidos ao início do experimento e serviram como referência na determinação da composição corporal inicial. As exigências líquidas de proteína e energia para ganho de 1 kg de peso corporal vazio (PCV foram estimadas pela equação Y' = a. b. X (b-1, em que a e b são os coeficientes das equações de regressão dos conteúdos de energia e proteína e X, o PCV dos animais. O teste de identidade de modelos não-lineares indicou não haver diferenças entre grupos genéticos para as exigências de energia e proteína para ganho de peso. Verificou-se decréscimo de 10,6% nas exigências de proteína e elevação de 37,8% nas exigências de energia para ganho de peso entre 250 e 550 kg, o que está relacionado à elevação do teor de gordura e à redução no teor de proteína com o acréscimo no PCV. As exigências líquidas de proteína e energia para ganho de peso foram estimadas em 143,5 g e 4,7 Mcal para o peso vivo de 450 kg.The objectives of this trial were to estimate gain composition and energy and protein requirements for weight gain of purebred and crossbred Nellore. Sixty young bulls averaging 10 to 11 months of age from four genetic groups: Nellore, F1 Nellore x Angus, F1 Nellore x Brown Swiss and F1 Nellore x Simental and initial average body weights of 286, 309, 333 and 310 kg, respectively, were used in this study. A completely randomized design was adopted and bulls from

Design of Gain Scheduling Control Using State Derivative Feedback

Directory of Open Access Journals (Sweden)

Lázaro Ismael Hardy Llins

2017-01-01

Full Text Available In recent years, the study of systems subject to time-varying parameters has awakened the interest of many researchers. The gain scheduling control strategy guarantees a good performance for systems of this type and also is considered as the simplest to deal with problems of this nature. Moreover, the class of systems in which the state derivative signals are easier to obtain than the state signals, such as in the control for reducing vibrations in a mechanical system, has gained an important hole in control theory. Considering those ideas, we propose sufficient conditions via LMI for designing a gain scheduling controller using state derivative feedback. The D-stability methodology was used for improving the performance of the transitory response. Practical implementation in an active suspension system and comparison with other methods validates the efficiency of the proposed strategy.

Bariatric surgery insurance requirements independently predict surgery dropout.

Science.gov (United States)

Love, Kaitlin M; Mehaffey, J Hunter; Safavian, Dana; Schirmer, Bruce; Malin, Steven K; Hallowell, Peter T; Kirby, Jennifer L

2017-05-01

Many insurance companies have considerable prebariatric surgery requirements despite a lack of evidence for improved clinical outcomes. The hypothesis of this study is that insurance-specific requirements will be associated with a decreased progression to surgery and increased delay in time to surgery. Retrospective data collection was performed for patients undergoing bariatric surgery evaluation from 2010-2015. Patients who underwent surgery (SGY; n = 827; mean body mass index [BMI] 49.1) were compared with those who did not (no-SGY; n = 648; mean BMI: 49.4). Univariate and multivariate analysis were performed to identify specific co-morbidity and insurance specific predictors of surgical dropout and time to surgery. A total of 1475 patients using 12 major insurance payors were included. Univariate analysis found insurance requirements associated with surgical drop out included longer median diet duration (no-SGY = 6 mo; SGY = 3 mo; Psurgery dropout. Additionally, surgical patients had an average interval between initial visit and surgery of 5.8±4.6 months with significant weight gain (2.1 kg, Psurgery insurance requirements were associated with lack of patient progression to surgery in this study. In addition, delays in surgery were associated with preoperative weight gain. Although prospective and multicenter studies are needed, these findings have major policy implications suggesting insurance requirements may need to be reconsidered to improve medical care. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Application of systems engineering to determine performance requirements for repository waste packages

International Nuclear Information System (INIS)

Aitken, E.A.; Stimmell, G.L.

1987-01-01

The waste package for a nuclear waste repository in salt must contribute substantially to the performance objectives defined by the Salt Repository Project (SRP) general requirements document governing disposal of high-level waste. The waste package is one of the engineered barriers providing containment. In establishing the performance requirements for a project focused on design and fabrication of the waste package, the systems engineering methodology has been used to translate the hierarchy requirements for the repository system to specific performance requirements for design and fabrication of the waste package, a subsystem of the repository. This activity is ongoing and requires a methodology that provides traceability and is capable of iteration as baseline requirements are refined or changed. The purpose of this summary is to describe the methodology being used and the way it can be applied to similar activities in the nuclear industry

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.

Dynamic resource allocation using performance forecasting

NARCIS (Netherlands)

Moura, Paulo; Kon, Fabio; Voulgaris, Spyros; Van Steen, Maarten

2016-01-01

To benefit from the performance gains and cost savings enabled by elasticity in cloud IaaS environments, effective automated mechanisms for scaling are essential. This automation requires monitoring system status and defining criteria to trigger allocation and deallocation of resources. While these

Enhancing Diversity in Undergraduate Science: Self-Efficacy Drives Performance Gains with Active Learning.

Science.gov (United States)

Ballen, Cissy J; Wieman, Carl; Salehi, Shima; Searle, Jeremy B; Zamudio, Kelly R

2017-01-01

Efforts to retain underrepresented minority (URM) students in science, technology, engineering, and mathematics (STEM) have shown only limited success in higher education, due in part to a persistent achievement gap between students from historically underrepresented and well-represented backgrounds. To test the hypothesis that active learning disproportionately benefits URM students, we quantified the effects of traditional versus active learning on student academic performance, science self-efficacy, and sense of social belonging in a large (more than 250 students) introductory STEM course. A transition to active learning closed the gap in learning gains between non-URM and URM students and led to an increase in science self-efficacy for all students. Sense of social belonging also increased significantly with active learning, but only for non-URM students. Through structural equation modeling, we demonstrate that, for URM students, the increase in self-efficacy mediated the positive effect of active-learning pedagogy on two metrics of student performance. Our results add to a growing body of research that supports varied and inclusive teaching as one pathway to a diversified STEM workforce. © 2017 C. J. Ballen et al. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

MOS current gain cells with electronically variable gain and constant bandwidth

NARCIS (Netherlands)

Klumperink, Eric A.M.; Seevinck, Evert

1989-01-01

Two MOS current gain cells are proposed that provide linear amplification of currents supplied by several linear MOS V-I converters. The gain is electronically variable by a voltage or a current and can be made insensitive to temperature and IC processing. The gain cells have a constant

Exploration of the Trade Space Between Unmanned Aircraft Systems Descent Maneuver Performance and Sense-and-Avoid System Performance Requirements

Science.gov (United States)

Jack, Devin P.; Hoffler, Keith D.; Johnson, Sally C.

2014-01-01

A need exists to safely integrate Unmanned Aircraft Systems (UAS) into the United States' National Airspace System. Replacing manned aircraft's see-and-avoid capability in the absence of an onboard pilot is one of the key challenges associated with safe integration. Sense-and-avoid (SAA) systems will have to achieve yet-to-be-determined required separation distances for a wide range of encounters. They will also need to account for the maneuver performance of the UAS they are paired with. The work described in this paper is aimed at developing an understanding of the trade space between UAS maneuver performance and SAA system performance requirements, focusing on a descent avoidance maneuver. An assessment of current manned and unmanned aircraft performance was used to establish potential UAS performance test matrix bounds. Then, near-term UAS integration work was used to narrow down the scope. A simulator was developed with sufficient fidelity to assess SAA system performance requirements. The simulator generates closest-point-of-approach (CPA) data from the wide range of UAS performance models maneuvering against a single intruder with various encounter geometries. Initial attempts to model the results made it clear that developing maneuver performance groups is required. Discussion of the performance groups developed and how to know in which group an aircraft belongs for a given flight condition and encounter is included. The groups are airplane, flight condition, and encounter specific, rather than airplane-only specific. Results and methodology for developing UAS maneuver performance requirements are presented for a descent avoidance maneuver. Results for the descent maneuver indicate that a minimum specific excess power magnitude can assure a minimum CPA for a given time-to-go prediction. However, smaller amounts of specific excess power may achieve or exceed the same CPA if the UAS has sufficient speed to trade for altitude. The results of this study will

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.

Gaining environmental resource consents: a New Zealand experience

International Nuclear Information System (INIS)

Hopkins, K.N.; Pritchard, N.E.

1995-01-01

In 1991 the Electricity Corporation of New Zealand was faced with the renewal of existing permits and rights under the requirements of the newly-passed Resource Management Act. Specifically for Huntly Power Station a strategy was required to ensure new Consents were gained to replace Water Rights and a Clean Air Act Licence due to expire in 1994. Key aspects of the Act are environmental protection, a requirement to consider Maori cultural concerns, and the need for a public participation stage in the Consents process. This paper documents aspects of the work completed to ensure Huntly gained its new Air and Water Resource Consents and indicates follow-up work in progress. Most attention in the water area focused on the discharge of condenser cooling water into the Waikato River with studies on fish health, migration and breeding habits being carried out. A novel solution involving the installation of 'Iowa Vanes' in the river has been decided on to optimize effective mixing of the cooling water with the river channel in front of the Station and thus minimize the effect of warm water entering the river. (author). 3 figs., 3 refs

Sound pressure gain produced by the human middle ear.

Science.gov (United States)

Kurokawa, H; Goode, R L

1995-10-01

The acoustic function of the middle ear is to match sound passing from the low impedance of air to the high impedance of cochlear fluid. Little information is available on the actual middle ear pressure gain in human beings. This article describes experiments on middle ear pressure gain in six fresh human temporal bones. Stapes footplate displacement and phase were measured with a laser Doppler vibrometer before and after removal of the tympanic membrane, malleus, and incus. Acoustic insulation of the round window with clay was performed. Umbo displacement was also measured before tympanic membrane removal to assess baseline tympanic membrane function. The middle ear has its major gain in the lower frequencies, with a peak near 0.9 kHz. The mean gain was 23.0 dB below 1.0 kHz, the resonant frequency of the middle ear; the mean peak gain was 26.6 dB. Above 1.0 kHz, the second pressure gain decreased at a rate of -8.6 dB/octave, with a mean gain of 6.5 dB at 4.0 kHz. Only a small amount of gain was present above 7.0 kHz. Significant individual differences in pressure gain were found between ears that appeared related to variations in tympanic membrane function and not to variations in cochlear impedance.

Technical Note: Modification of the standard gain correction algorithm to compensate for the number of used reference flat frames in detector performance studies

International Nuclear Information System (INIS)

Konstantinidis, Anastasios C.; Olivo, Alessandro; Speller, Robert D.

2011-01-01

Purpose: The x-ray performance evaluation of digital x-ray detectors is based on the calculation of the modulation transfer function (MTF), the noise power spectrum (NPS), and the resultant detective quantum efficiency (DQE). The flat images used for the extraction of the NPS should not contain any fixed pattern noise (FPN) to avoid contamination from nonstochastic processes. The ''gold standard'' method used for the reduction of the FPN (i.e., the different gain between pixels) in linear x-ray detectors is based on normalization with an average reference flat-field. However, the noise in the corrected image depends on the number of flat frames used for the average flat image. The aim of this study is to modify the standard gain correction algorithm to make it independent on the used reference flat frames. Methods: Many publications suggest the use of 10-16 reference flat frames, while other studies use higher numbers (e.g., 48 frames) to reduce the propagated noise from the average flat image. This study quantifies experimentally the effect of the number of used reference flat frames on the NPS and DQE values and appropriately modifies the gain correction algorithm to compensate for this effect. Results: It is shown that using the suggested gain correction algorithm a minimum number of reference flat frames (i.e., down to one frame) can be used to eliminate the FPN from the raw flat image. This saves computer memory and time during the x-ray performance evaluation. Conclusions: The authors show that the method presented in the study (a) leads to the maximum DQE value that one would have by using the conventional method and very large number of frames and (b) has been compared to an independent gain correction method based on the subtraction of flat-field images, leading to identical DQE values. They believe this provides robust validation of the proposed method.

Multimodal Pilot Behavior in Multi-Axis Tracking Tasks with Time-Varying Motion Cueing Gains

Science.gov (United States)

Zaal, P. M. T; Pool, D. M.

2014-01-01

In a large number of motion-base simulators, adaptive motion filters are utilized to maximize the use of the available motion envelope of the motion system. However, not much is known about how the time-varying characteristics of such adaptive filters affect pilots when performing manual aircraft control. This paper presents the results of a study investigating the effects of time-varying motion filter gains on pilot control behavior and performance. An experiment was performed in a motion-base simulator where participants performed a simultaneous roll and pitch tracking task, while the roll and/or pitch motion filter gains changed over time. Results indicate that performance increases over time with increasing motion gains. This increase is a result of a time-varying adaptation of pilots' equalization dynamics, characterized by increased visual and motion response gains and decreased visual lead time constants. Opposite trends are found for decreasing motion filter gains. Even though the trends in both controlled axes are found to be largely the same, effects are less significant in roll. In addition, results indicate minor cross-coupling effects between pitch and roll, where a cueing variation in one axis affects the behavior adopted in the other axis.

Optical gain and gain suppression of quantum-well lasers with valence band mixing

International Nuclear Information System (INIS)

Ahn, D.; Chuang, S.L.

1990-01-01

The effects of valence band mixing on the nonlinear gains of quantum-well lasers are studied theoretically. The authors' analysis is based on the multiband effective-mass theory and the density matrix formalism with intraband relaxation taken into account. The gain and the gain-suppression coefficient of a quantum-well laser are calculated from the complex optical susceptibility obtained by the density matrix formulation with the theoretical dipole moments obtained from the multiband effective-mass theory. The calculated gain spectrum shows that there are remarkable differences (both in peak amplitude and spectral shape) between our model with valence band mixing and the conventional parabolic band model. The shape of the gain spectrum calculated by the authors' model becomes more symmetric due to intraband relaxation together with nonparabolic energy dispersions and is closer to the experimental observations when compared with the conventional method using the parabolic band model and the multiband effective-mass calculation without intraband relaxation. Both give quite asymmetric gain spectra. Optical intensity in the GaAs active region is estimated by solving rate equations for the stationary states with nonlinear gain suppression. The authors calculate the mode gain for the resonant mode including the gain suppression, which results in spectral hole burning of the gain spectrum

Practical experience and lessons learned through implementation of Appendix VIII performance demonstration requirements

International Nuclear Information System (INIS)

Ashwin, P.J.; Becker, F.L.; Latiolais, C.L.; Spanner, J.C.

1996-01-01

To provide the US nuclear industry with a uniform implementation of the Performance Demonstration requirements within the 1989 edition of ASME Section XI, Appendix VIII, representatives from all US nuclear utilities formed the Performance Demonstration Initiative (PDI). The PDI recognized the potential benefits that Appendix VIII offered the nuclear industry and initiated a proactive approach to implement the requirements. In doing so it was expected that performance demonstration of ultrasonic examination procedures would allow for improvement in the efficiency and credibility of inservice inspection to be realized. Explicit within the performance demonstration requirements of Appendix VIII is the need for a Performance Demonstration Administrator, a difficult requirement to fulfill. Not only must the administrator exhibit the attributes of understanding the demonstration requirements, but also have solid technical knowledge, integrity and be able to interface with the industry at all levels, from operations to regulatory. For the nuclear industry, the EPRI NDE Center is an obvious choice to fulfill this position. This paper provides a brief background of the PDI, a nuclear industry-wide initiative to implement the performance demonstration requirements of Appendix VIII. Even though the consensus approach adopted by the PDI is discussed, the paper's primary objective is to provide examples of the lessons learned by the Center through the specific requirements of Appendix VIII

Review of health and productivity gains from better IEQ

Energy Technology Data Exchange (ETDEWEB)

Fisk, William J.

2000-08-01

The available scientific data suggest that existing technologies and procedures can improve indoor environmental quality (IEQ) in a manner that significantly increases productivity and health. While there is considerable uncertainty in the estimates of the magnitudes of productivity gains that may be obtained, the projected gains are very large. For the U.S., the estimated potential annual savings and productivity gains are $6 to $14 billion from reduced respiratory disease, $2 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance that are unrelated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment.

Performance requirements for the double-shell tank system: Phase 1

International Nuclear Information System (INIS)

Claghorn, R.D.

1998-01-01

This document establishes performance requirements for the double-shell tank system. These requirements, in turn, will be incorporated in the System Specification for the Double-Shell Tank System (Grenard and Claghorn 1998). This version of the document establishes requirements that are applicable to the first phase (Phase 1) of the Tank Waste Remediation System (TWRS) mission described in the TWRS Mission Analysis Report (Acree 1998). It does not specify requirements for either the Phase 2 mission or the double-shell tank system closure period

Capacity gains of buffer-aided moving relays

KAUST Repository

Zafar, Ammar

2017-03-14

This work investigates the gain due to reduction in path loss by deploying buffer-aided moving relaying. In particular, the increase in gain due to moving relays is studied for dual-hop broadcast channels and the bidirectional relay channel. It is shown that the exploited gains in these channels due to buffer-aided relaying can be enhanced by utilizing the fact that a moving relay can communicate with the terminal closest to it and store the data in the buffer and then forward the data to the intended destination when it comes in close proximity with the destination. Numerical results show that for both the considered channels the achievable rates are increased as compared to the case of stationary relays. Numerical results also show that more significant increase in performance is seen when the relay moves to-and-fro between the source and the relay.

Capacity gains of buffer-aided moving relays

KAUST Repository

Zafar, Ammar; Shaqfeh, Mohammad; Alnuweiri, Hussein; Alouini, Mohamed-Slim

2017-01-01

This work investigates the gain due to reduction in path loss by deploying buffer-aided moving relaying. In particular, the increase in gain due to moving relays is studied for dual-hop broadcast channels and the bidirectional relay channel. It is shown that the exploited gains in these channels due to buffer-aided relaying can be enhanced by utilizing the fact that a moving relay can communicate with the terminal closest to it and store the data in the buffer and then forward the data to the intended destination when it comes in close proximity with the destination. Numerical results show that for both the considered channels the achievable rates are increased as compared to the case of stationary relays. Numerical results also show that more significant increase in performance is seen when the relay moves to-and-fro between the source and the relay.

Image-converter streak cameras with very high gain

International Nuclear Information System (INIS)

1975-01-01

A new camera is described with slit scanning and very high photonic gain (G=5000). Development of the technology of tubes and microchannel plates has enabled integration of such an amplifying element in an image converter tube which does away with the couplings and the intermediary electron-photon-electron conversions of the classical converter systems having external amplification. It is thus possible to obtain equal or superior performance while retaining considerable gain for the camera, great compactness, great flexibility in use, and easy handling. (author)

Reactive relay selection in underlay cognitive networks with fixed gain relays

KAUST Repository

Hussain, Syed Imtiaz

2012-06-01

Best relay selection is a bandwidth efficient technique for multiple relay environments without compromising the system performance. The problem of relay selection is more challenging in underlay cognitive networks due to strict interference constraints to the primary users. Generally, relay selection is done on the basis of maximum end-to-end signal to noise ratio (SNR). However, it requires large amounts of channel state information (CSI) at different network nodes. In this paper, we present and analyze a reactive relay selection scheme in underlay cognitive networks where the relays are operating with fixed gains near a primary user. The system model minimizes the amount of CSI required at different nodes and the destination selects the best relay on the basis of maximum relay to destination SNR. We derive close form expressions for the received SNR statistics, outage probability, bit error probability and average channel capacity of the system. Simulation results are also presented to confirm the validity of the derived expressions. © 2012 IEEE.

42 CFR 84.103 - Man tests; performance requirements.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Man tests; performance requirements. 84.103 Section 84.103 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.103 Man tests;...

Development of DSRC device and communication system performance measures recommendations for DSRC OBE performance and security requirements.

Science.gov (United States)

2016-05-22

This report presents recommendations for minimum DSRC device communication performance and security : requirements to ensure effective operation of the DSRC system. The team identified recommended DSRC : communications requirements aligned to use cas...

Gain-Scheduled Control of a Fossil-Fired Power Plant Boiler

DEFF Research Database (Denmark)

Hangstrup, M.; Stoustrup, Jakob; Andersen, Palle

1999-01-01

-scheduling which interpolates between unstable controllers is not allowed using traditional schemes. The results show that a considerable optimization of the conventional controlled system is obtainable. Also the gain-scheduled optimizing controller is seen to have a superior performance compared to the fixed LTI......In this paper the objective is to optimize the control of a coal fired 250 MW power plant boiler. The conventional control system is supplemented with a multivariable optimizing controller operating in parallel with the conventional control system. Due to the strong dependence of the gains...... and dynamics upon the load, it is beneficial to consider a gain-scheduling control approach. Optimization using complex mu synthesis results in unstable LTI controllers in some operating points of the boiler. A recent gain-scheduling approach allowing for unstable fixed LTI controllers is applied. Gain...

Section 3: Quality and Value-Based Requirements

Science.gov (United States)

Mylopoulos, John

Traditionally, research and practice in software engineering has focused its attention on specific software qualities, such as functionality and performance. According to this perspective, a system is deemed to be of good quality if it delivers all required functionality (“fitness-for-purpose”) and its performance is above required thresholds. Increasingly, primarily in research but also in practice, other qualities are attracting attention. To facilitate evolution, maintainability and adaptability are gaining popularity. Usability, universal accessibility, innovativeness, and enjoyability are being studied as novel types of non-functional requirements that we do not know how to define, let alone accommodate, but which we realize are critical under some contingencies. The growing importance of the business context in the design of software-intensive systems has also thrust economic value, legal compliance, and potential social and ethical implications into the forefront of requirements topics. A focus on the broader user environment and experience, as well as the organizational and societal implications of system use, thus has become more central to the requirements discourse. This section includes three contributions to this broad and increasingly important topic.

14 CFR 151.49 - Performance of construction work: Contract requirements.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Performance of construction work: Contract... § 151.49 Performance of construction work: Contract requirements. (a) Contract provisions. In addition to any other provisions necessary to ensure completion of the work in accordance with the grant...

Radioactive material package test standards and performance requirements - public perception

International Nuclear Information System (INIS)

Pope, R.B.; Shappert, L.B.; Rawl, R.R.

1992-01-01

This paper addresses issues related to the public perception of the regulatory test standards and performance requirements for packaging and transporting radioactive material. Specifically, it addresses the adequacy of the package performance standards and testing for Type B packages, which are those packages designed for transporting the most hazardous quantities and forms of radioactive material. Type B packages are designed to withstand accident conditions in transport. To improve public perception, the public needs to better understand: (a) the regulatory standards and requirements themselves, (b) the extensive history underlying their development, and (c) the soundness of the technical foundation. The public needs to be fully informed on studies, tests, and analyses that have been carried out worldwide and form the basis of the regulatory standards and requirements. This paper provides specific information aimed at improving the public perception of packages test standards

Association of Group Prenatal Care With Gestational Weight Gain.

Science.gov (United States)

Kominiarek, Michelle A; Crockett, Amy; Covington-Kolb, Sarah; Simon, Melissa; Grobman, William A

2017-04-01

To compare gestational weight gain among women in group prenatal care with that of women in individual prenatal care. In this retrospective cohort study, women who participated in group prenatal care from 2009 to 2015 and whose body mass indexes (BMIs) and gestational weight gain were recorded were matched with the next two women who had the same payer type, were within 2-kg/m prepregnancy BMI and 2-week gestational age at delivery, and had received individual prenatal care. Bivariate comparisons of demographics and antenatal complications were performed for women in group and individual prenatal care, and weight gain was categorized as "below," "met," or "exceeded" goals according to the 2009 Institute of Medicine guidelines. Logistic regression analysis estimated the association between excessive weight gain and model of care, with adjustment for confounders, stratified by BMI. Women in group prenatal care (n=2,117) were younger and more commonly non-Hispanic black, nulliparous, and without gestational diabetes (P≤.005 for all). Women in group prenatal care more commonly exceeded the weight gain goals (55% compared with 48%, Pprenatal care, compared with individual prenatal care, is associated with excessive gestational weight gain.

40 CFR Table 5 to Subpart Xxxx of... - Requirements for Performance Tests

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Requirements for Performance Tests 5 Table 5 to Subpart XXXX of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED.... XXXX, Table 5 Table 5 to Subpart XXXX of Part 63—Requirements for Performance Tests As stated in § 63...

Gaining the Edge: Connecting with the Millennials

Science.gov (United States)

2008-12-01

Cleaver’s and Partridge’s) entered Americans’ living rooms nightly. The Osmond’s and Beatles captivated music of the Boomer’s youth. Powerful...AIR WAR COLLEGE AIR UNIVERSITY GAINING THE EDGE: CONNECTING WITH THE MILLENNIALS by Kay A. Smith, Lt Col, USAF A Research Report Submitted to... the Faculty In Partial Fulfillment of the Graduation Requirements 1 December 2008 DISCLAIMER The views expressed in this academic research

40 CFR 63.344 - Performance test requirements and test methods.

Science.gov (United States)

2010-07-01

... electroplating tanks or chromium anodizing tanks. The sampling time and sample volume for each run of Methods 306... Chromium Anodizing Tanks § 63.344 Performance test requirements and test methods. (a) Performance test... Emissions From Decorative and Hard Chromium Electroplating and Anodizing Operations,” appendix A of this...

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 ...

34 CFR 462.41 - How must tests be administered in order to accurately measure educational gain?

Science.gov (United States)

2010-07-01

... measure educational gain? 462.41 Section 462.41 Education Regulations of the Offices of the Department of... EDUCATIONAL GAIN IN THE NATIONAL REPORTING SYSTEM FOR ADULT EDUCATION What Requirements Must States and Local Eligible Providers Follow When Measuring Educational Gain? § 462.41 How must tests be administered in order...

Study on high gain broadband optical parametric chirped pulse amplification

International Nuclear Information System (INIS)

Zhang, S.K.; Fujita, M.; Yamanaka, C.; Yoshida, H.; Kodama, R.; Fujita, H.; Nakatsuka, M.; Izawa, Y.

2000-01-01

Optical parametric chirped pulse amplification has apparent advantages over the current schemes for high energy ultrashort pulse amplification. High gain in a single pass amplification, small B-integral, low heat deposition, high contrast ratio and, especially the extremely broad gain bandwidth with large-size crystals available bring people new hope for over multi-PW level at which the existing Nd:glass systems suffered difficulties. In this paper we present simulation and experimental studies for a high gain optical parametric chirped pulse amplification system which may be used as a preamplifier to replace the current complicated regenerative system or multi-pass Ti:sapphire amplifiers. Investigations on the amplification bandwidth and gain with BBO are performed. Analysis and discussions are also given. (author)

14 CFR 151.45 - Performance of construction work: General requirements.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Performance of construction work: General... § 151.45 Performance of construction work: General requirements. (a) All construction work under a... work under a project until— (1) The sponsor has furnished three conformed copies of the contract to the...

Required performance to the concrete structure of the accelerator facilities

International Nuclear Information System (INIS)

Irie, Masaaki; Yoshioka, Masakazu; Miyahara, Masanobu

2006-01-01

As for the accelerator facility, there is many a thing which is constructed as underground concrete structure from viewpoint such as cover of radiation and stability of the structure. Required performance to the concrete structure of the accelerator facility is the same as the general social infrastructure, but it has been possessed the feature where target performance differs largely. As for the body sentence, expressing the difference of the performance which is required from the concrete structure of the social infrastructure and the accelerator facility, construction management of the concrete structure which it plans from order of the accelerator engineering works facility, reaches to the design, supervision and operation it is something which expresses the method of thinking. In addition, in the future of material structural analysis of the concrete which uses the neutron accelerator concerning view it showed. (author)

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 ...

Adaptive Gain Scheduled Semiactive Vibration Control Using a Neural Network

Directory of Open Access Journals (Sweden)

Kazuhiko Hiramoto

2018-01-01

Full Text Available We propose an adaptive gain scheduled semiactive control method using an artificial neural network for structural systems subject to earthquake disturbance. In order to design a semiactive control system with high control performance against earthquakes with different time and/or frequency properties, multiple semiactive control laws with high performance for each of multiple earthquake disturbances are scheduled with an adaptive manner. Each semiactive control law to be scheduled is designed based on the output emulation approach that has been proposed by the authors. As the adaptive gain scheduling mechanism, we introduce an artificial neural network (ANN. Input signals of the ANN are the measured earthquake disturbance itself, for example, the acceleration, velocity, and displacement. The output of the ANN is the parameter for the scheduling of multiple semiactive control laws each of which has been optimized for a single disturbance. Parameters such as weight and bias in the ANN are optimized by the genetic algorithm (GA. The proposed design method is applied to semiactive control design of a base-isolated building with a semiactive damper. With simulation study, the proposed adaptive gain scheduling method realizes control performance exceeding single semiactive control optimizing the average of the control performance subject to various earthquake disturbances.

Application of gain scheduling to the control of batch bioreactors

Science.gov (United States)

Cardello, Ralph; San, Ka-Yiu

1987-01-01

The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

Brightness and coherence of radiation from undulators and high-gain free electron lasers

International Nuclear Information System (INIS)

Kim, Kwang-Je.

1987-03-01

The purpose of this paper is to review the radiation characteristics of undulators and high-gain free electron lasers (FELs). The topics covered are: a phase-space method in wave optics and synchrotron radiation, coherence from the phase-space point of view, discussions of undulator performances in next-generation synchrotron radiation facility and the characteristics of the high-gain FELs and their performances

Correlations of circulating peptide YY and ghrelin with body weight, rate of weight gain, and time required to achieve the recommended daily intake in preterm infants.

Science.gov (United States)

Chen, XiaFang; Du, XueLiang; Zhu, JianXing; Xie, LiJuan; Zhang, YongJun; He, ZhenJuan

2012-07-01

The objective was to elucidate the relationships between serum concentrations of the gut hormone peptide YY (PYY) and ghrelin and growth development in infants for potential application to the clinical observation index. Serum concentrations of PYY and ghrelin were measured using radioimmunoassay from samples collected at the clinic. For each patient, gestational age, birth weight, time required to return to birth weight, rate of weight gain, time required to achieve recommended daily intake (RDI) standards, time required for full-gastric feeding, duration of hospitalization, and time of administration of total parenteral nutrition were recorded. Serum PYY and ghrelin concentrations were significantly higher in the preterm group (N = 20) than in the full-term group (N = 20; P weight, and the degree of correlation varied with age. Serum ghrelin concentration correlated negatively with birth weight and positively with the time required to achieve RDI (P newborns and to determine the usefulness of measuring these hormones in clinical practice.

The indication area of a diagnostic test. Part I--discounting gain and loss in diagnostic certainty

NARCIS (Netherlands)

Stalpers, Lukas J. A.; Nelemans, Patty J.; Geurts, Sandra M. E.; Jansen, Erik; de Boer, Peter; Verbeek, André L. M.

2015-01-01

Test performance is conventionally expressed by gain in diagnostic certainty. We propose net diagnostic gain and indication area as more appropriate measures of test performance; then, the loss in certainty due to misclassification and the information of "no test" would be performed are taken into

Contrast Gain Control Model Fits Masking Data

Science.gov (United States)

Watson, Andrew B.; Solomon, Joshua A.; Null, Cynthia H. (Technical Monitor)

1994-01-01

We studied the fit of a contrast gain control model to data of Foley (JOSA 1994), consisting of thresholds for a Gabor patch masked by gratings of various orientations, or by compounds of two orientations. Our general model includes models of Foley and Teo & Heeger (IEEE 1994). Our specific model used a bank of Gabor filters with octave bandwidths at 8 orientations. Excitatory and inhibitory nonlinearities were power functions with exponents of 2.4 and 2. Inhibitory pooling was broad in orientation, but narrow in spatial frequency and space. Minkowski pooling used an exponent of 4. All of the data for observer KMF were well fit by the model. We have developed a contrast gain control model that fits masking data. Unlike Foley's, our model accepts images as inputs. Unlike Teo & Heeger's, our model did not require multiple channels for different dynamic ranges.

The Role of Morphology and Electronic Chain Aggregation on the Optical Gain Properties of Semiconducting Conjugated Polymers

Science.gov (United States)

Lampert, Zachary Evan

thresholds and large net gains are highly desirable. In this thesis, we also discuss novel routes we developed for enhancement of ASE performance in MEH-PPV thin film planar waveguides. The first technique relied on improving the distribution of the TE0 guided mode in the CP gain layer through optimization of waveguide architecture. This was achieved by fabricating symmetric heterostructure waveguides formed from a core layer of MEH-PPV sandwiched between an SiO2 buffer and index matched poly(methyl methacrylate) (PMMA) cover layer. Relative to asymmetric waveguides of Si(100)/SiO2/MEH-PPV/Air, symmetric waveguides exhibited increased optical confinement and reduced propagation loss enabling lower ASE threshold (40%) and higher net gain (50%). Independent of device architecture and degree of aggregation in the films, we discovered that optical gain is also highly dependent on the excitation conditions, specifically the temporal width of the pump laser pulses. A 400% increase in net gain was achieved under transient (25 picosecond pulses), compared to quasi-steady state (8 nanosecond pulses), excitation conditions. This large difference is attributed to low pumping efficiency and increased non-radiative recombination under ns pumping, which reduces the emission cross-section resulting in a net decrease in gain. The gain values we achieved in the ps regime are to the best of our knowledge the largest gain values reported to date for thin conjugated polymer films measured using the variable stripe length (VSL) technique. Films pumped in the transient regime also required 30 times less pump energy density to reach threshold in comparison with films pumped in the quasi-steady state regime, although the excited state densities were essentially the same. These results demonstrate that the pumping efficiency, and hence generation rate of excited states in a gain medium, can be dramatically increased by using pump laser pulses that are shorter than the exciton luminescence lifetime

Characterizing gestational weight gain in a cohort of Indigenous Australian women.

Science.gov (United States)

Schumacher, Tracy L; Weatherall, Loretta; Keogh, Lyniece; Sutherland, Kathryn; Collins, Clare E; Pringle, Kirsty G; Rae, Kym M

2018-05-01

to determine the adequacy of gestational weight gain for a cohort of Indigenous Australian women and investigate whether it is associated with pre-pregnancy body mass index. analysis of observational data collected from a longitudinal cohort study that follows Indigenous Australian women through pregnancy. women recruited through antenatal clinics in regional and remote towns in NSW, Australia to the Gomeroi gaaynggal program. 110 pregnant women who either identified as being an Indigenous Australian or as carrying an Indigenous child. measurements included weight and height, self-reported pre-pregnancy weight and smoking status, parity and health conditions that may contribute to gestational weight gain, such as hypertensive or diabetic disorders. Compared to the 2009 Institute of Medicine recommendations for gestational weight gain and based on prepregnancy body mass index, the rate of adequate gestational weight gain in this cohort was very low (15%). 32% of women had inadequate weight gain and 54% had excessive weight gain. The highest rate of excessive gestational weight gain was found in overweight women (74%), with rates of 48% and 50% found in healthy and obese (all classes) categories, respectively. Parity (coefficient 4.5, p<0.01) and hypertension (coefficient 4.8, p = 0.04) were found to be significantly associated with gestational weight gain in mixed model linear regression. few women gained adequate gestational weight gain in this study. Culturally acceptable ways of addressing this issue are needed for this group of women, as inadequate and excessive rates of gestational weight gain have health implications for women and their offspring. a systematic approach to addressing gestational weight gain within antenatal care is required, including asking about diet and exercise, for all women identifying as Indigenous Australian. Copyright © 2018 Elsevier Ltd. All rights reserved.

13 CFR 126.700 - What are the performance of work requirements for HUBZone contracts?

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What are the performance of work... ADMINISTRATION HUBZONE PROGRAM Contract Performance Requirements § 126.700 What are the performance of work... meet the performance of work requirements set forth in § 125.6(c) of this chapter. (b) In addition to...

Gains and losses of exclusivity in grocery retailing

NARCIS (Netherlands)

Gielens, K.J.P.; Gijsbrechts, E.; Dekimpe, M.G.

Conventional wisdom dictates that convenience goods should be distributed as intensively as possible. Still, exclusivity arrangements are rapidly gaining way in grocery retailing. We discuss the possible performance outcomes of exclusivity deals, and propose a unified framework (i) to quantify the

Influences of finite gain bandwidth on pulse propagation in parabolic fiber amplifiers with distributed gain profiles

International Nuclear Information System (INIS)

Zhao Jia-Sheng; Li Pan; Chen Xiao-Dong; Feng Su-Juan; Mao Qing-He

2012-01-01

The evolutions of the pulses propagating in decreasing and increasing gain distributed fiber amplifiers with finite gain bandwidths are investigated by simulations with the nonlinear Schrödinger equation. The results show that the parabolic pulse propagations in both the decreasing and the increasing gain amplifiers are restricted by the finite gain bandwidth. For a given input pulse, by choosing a small initial gain coefficient and gain variation rate, the whole gain for the pulse amplification limited by the gain bandwidth may be higher, which is helpful for the enhancement of the output linearly chirped pulse energy. Compared to the decreasing gain distributed fiber amplifier, the increasing gain distributed amplifier may be more conducive to suppress the pulse spectral broadening and increase the critical amplifier length for achieving a larger output linearly chirped pulse energy

Exigências Líquidas de Aminoácidos para Ganho de Peso de Nelores Não-Castrados Net Amino Acids Requirements for Weight Gain of Nellore Bulls

Directory of Open Access Journals (Sweden)

Fabiano Ferreira da Silva

2002-01-01

LW. The roughage used was Tyfton bermudagrass hay (Cynodon dactylon. After slaughter, all animal body parts were weighed and sampled. The samples were freeze dried to determine the dry matter, pre-degreased with ether, grinded and the concentrations of amino acids were determined. The net amino acids requirements for gain were calculated according to the factorial method, where the protein gain was multiplied by the empty body amino acids composition. The net amino acids requirements for maintenance were estimated. The sum of the metabolizable requirements for maintenance and gain composed the total metabolizable amino acids requirements. The net amino acids requirements for gain decreased with the increase of the animals live weight. The total metabolizable amino acids requirements, expressed in percentage of the total essential amino acids, did not change a lot as live weight increased, and the mean values were 2.66, 15.11, 6.09, 8.64, 9.26, 18.48, 8.33, 12.01, and 19.41 for methionine, lysine, histidine, phenylalanine, threonine, leucine, isoleucine, valine and arginine, respectively.

The Association of Antidepressant Medication and Body Weight Gain.

Directory of Open Access Journals (Sweden)

Sara Ranjbar

2013-04-01

Full Text Available Objective: To review the literature and discover which antidepressants are responsible for weight gain and then to discuss the areas with lack of adequate knowledge. Method: An electronic search was conducted through Medline, Pubmed, Cochrane library, and ScienceDirect. Forty nine empirical researches were identified and reviewed. Results: Amitriptyline, clomipramine, and mirtazapine have been associated with more weight gain induction in clinical studies, but not in animal-based studies. All TCAs have been reported to cause weight gain except protriptyline. MAOIs have been associated with weight gain. In SSRI group, citalopram and ecitalopram induce weight, yet mixed results exist for paroxetine and fluoxetine. Researches unanimously reported weight loss effect for bupropion. Some studies suggest contributing factors in the relationship of antidepressants with body weight changes including age, gender, base-line weights and treatment duration. Various results of different treatment durations have been reported in some cases but there are not continuous time-dependent studies for the influences of antidepressants on body weight changes. Conclusion: More studies are required to discover underlying mechanisms and the time-dependent effects of antidepressants on body weight changes.

Gas gain stability of MSGCs on borosilicate glass

International Nuclear Information System (INIS)

Berg, F.D. van den; Daum, C.; Eijk, B. van; Hartjes, F.G.; Udo, F.; Zhukov, V.

1996-01-01

The gas gain stability in Micro Strip Gas Counters fabricated on borosilicate glass has been investigated for operation at high radiation fluxes up to 10 5 Hz/mm 2 in a X-ray set-up. We discuss effects of short and long term irradiation on the gain for different voltage settings and strip metalisations. The application of a high drift field and a back plane on positive potential provides good high rate operation up to 10 4 Hz/mm 2 . Ageing is observed to be strongly dependent on the stirp metalisation; gold and nickel perform better than aluminium and copper. (orig.)

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.

Science.gov (United States)

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Materials, workmanship, construction, and performance...) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Hand Orange Smoke Distress Signals § 160.037-3 Materials, workmanship, construction, and performance requirements. (a...

High-performance indium gallium phosphide/gallium arsenide heterojunction bipolar transistors

Science.gov (United States)

Ahmari, David Abbas

Heterojunction bipolar transistors (HBTs) have demonstrated the high-frequency characteristics as well as the high linearity, gain, and power efficiency necessary to make them attractive for a variety of applications. Specific applications for which HBTs are well suited include amplifiers, analog-to-digital converters, current sources, and optoelectronic integrated circuits. Currently, most commercially available HBT-based integrated circuits employ the AlGaAs/GaAs material system in applications such as a 4-GHz gain block used in wireless phones. As modern systems require higher-performance and lower-cost devices, HBTs utilizing the newer, InGaP/GaAs and InP/InGaAs material systems will begin to dominate the HBT market. To enable the widespread use of InGaP/GaAs HBTs, much research on the fabrication, performance, and characterization of these devices is required. This dissertation will discuss the design and implementation of high-performance InGaP/GaAs HBTs as well as study HBT device physics and characterization.

Effects of Gain/Loss Framing in Cyber Defense Decision-Making

Energy Technology Data Exchange (ETDEWEB)

Bos, Nathan; Paul, Celeste; Gersh, John; Greenberg, Ariel; Piatko, Christine; Sperling, Scott; Spitaletta, Jason; Arendt, Dustin L.; Burtner, Edwin R.

2016-10-24

Cyber defense requires decision making under uncertainty. Yet this critical area has not been a strong focus of research in judgment and decision-making. Future defense systems, which will rely on software-defined networks and may employ ‘moving target’ defenses, will increasingly automate lower level detection and analysis, but will still require humans in the loop for higher level judgment. We studied the decision making process and outcomes of 17 experienced network defense professionals who worked through a set of realistic network defense scenarios. We manipulated gain versus loss framing in a cyber defense scenario, and found significant effects in one of two focal problems. Defenders that began with a network already in quarantine (gain framing) used a quarantine system more than those that did not (loss framing). We also found some difference in perceived workload and efficacy. Alternate explanations of these findings and implications for network defense are discussed.

Stress effects on framed decisions: there are differences for gains and losses

Directory of Open Access Journals (Sweden)

Stephan ePabst

2013-10-01

Full Text Available Recent studies have shown that acute stress can lead to riskier decision making. Yet, the underlying mechanisms of the stress effects on decisions under risk remain poorly understood. To gain a better understanding of decision-making processes and potential strategy application under stress, we investigated decision making in pure gain and loss domains with unequal expected values across alternatives. We conducted an experimental study with a 2 × 2 design (stress vs. no stress and gain domain vs. loss domain. The Trier Social Stress Test (TSST was utilized to induce acute stress. Controls performed the placebo-TSST. To validate the stress response we measured salivary cortisol and alpha amylase concentrations. We used a modified version of the Game of Dice Task (GDT to assess decision-making performance in a gain and a loss domain. Results showed that non-stressed participants of the gain domain decided less risky compared to those of the loss domain. This behavior is in accordance with previous studies and indicates the stability of the framing effect in even more complex tasks with changing expected values across alternatives. Stress did not alter risk taking behavior in the gain domain. Yet, in the loss domain stressed participants decided less risky compared to controls. Additionally, the data support earlier findings of longer reaction times in loss compared to gain domains due to higher cognitive effort for loss-framed decisions. It is discussed that stress may lead to reduced amygdala activation, which has been found to reduce riskier decisions in a loss domain. With respect to earlier results of riskier decisions in tasks that unite both gain and loss domains, it is discussed whether stress leads to a stronger evaluation of high gains and a neglect of losses.

Stress effects on framed decisions: there are differences for gains and losses.

Science.gov (United States)

Pabst, Stephan; Brand, Matthias; Wolf, Oliver T

2013-01-01

Recent studies have shown that acute stress can lead to riskier decision making. Yet, the underlying mechanisms of the stress effects on decisions under risk remain poorly understood. To gain a better understanding of decision-making processes and potential strategy application under stress, we investigated decision making in pure gain and loss domains with unequal expected values (EVs) across alternatives. We conducted an experimental study with a 2 × 2 design (stress vs. no stress and gain domain vs. loss domain). The Trier Social Stress Test (TSST) was utilized to induce acute stress. Controls performed the placebo-TSST (p-TSST). To validate the stress response we measured salivary cortisol and alpha-amylase concentrations. We used a modified version of the Game of Dice Task (GDT) to assess decision-making performance in a gain and a loss domain. Results showed that non-stressed participants made less risky decisions in the gain domain compared to those of the loss domain. This behavior is in accordance with previous studies and indicates the stability of the framing effect in even more complex tasks with changing EVs across alternatives. Stress did not alter risk taking behavior in the gain domain. Yet, in the loss domain stressed participants made less risky decisions compared to controls. Additionally, the data support earlier findings of longer reaction times in loss compared to gain domains due to higher cognitive effort for loss-framed decisions. It is discussed that stress may lead to reduced amygdala activation, which has been found to reduce riskier decisions in a loss domain. With respect to earlier results of riskier decisions in tasks that unite both gain and loss domains, it is discussed whether stress leads to a stronger evaluation of high gains and a neglect of losses.

Use of simple transport equations to estimate waste package performance requirements

International Nuclear Information System (INIS)

Wood, B.J.

1982-01-01

A method of developing waste package performance requirements for specific nuclides is described. The method is based on: Federal regulations concerning permissible concentrations in solution at the point of discharge to the accessible environment; a simple and conservative transport model; baseline and potential worst-case release scenarios. Use of the transport model enables calculation of maximum permissible release rates within a repository in basalt for each of the scenarios. The maximum permissible release rates correspond to performance requirements for the engineered barrier system. The repository was assumed to be constructed in a basalt layer. For the cases considered, including a well drilled into an aquifer 1750 m from the repository center, little significant advantage is obtained from a 1000-yr as opposed to a 100-yr waste package. A 1000-yr waste package is of importance only for nuclides with half-lives much less than 100 yr which travel to the accessible environment in much less than 1000 yr. Such short travel times are extremely unlikely for a mined repository. Among the actinides, the most stringent maximum permissible release rates are for 236 U and 234 U. A simple solubility calculation suggests, however, that these performance requirements can be readily met by the engineered barrier system. Under the reducing conditions likely to occur in a repository located in basalt, uranium would be sufficiently insoluble that no solution could contain more than about 0.01% of the maximum permissible concentration at saturation. The performance requirements derived from the one-dimensional modeling approach are conservative by at least one to two orders of magnitude. More quantitative three-dimensional modeling at specific sites should enable relaxation of the performance criteria derived in this study. 12 references, 8 figures, 8 tables

Multi-parameter Nonlinear Gain Correction of X-ray Transition Edge Sensors for the X-ray Integral Field Unit

Science.gov (United States)

Cucchetti, E.; Eckart, M. E.; Peille, P.; Porter, F. S.; Pajot, F.; Pointecouteau, E.

2018-04-01

With its array of 3840 Transition Edge Sensors (TESs), the Athena X-ray Integral Field Unit (X-IFU) will provide spatially resolved high-resolution spectroscopy (2.5 eV up to 7 keV) from 0.2 to 12 keV, with an absolute energy scale accuracy of 0.4 eV. Slight changes in the TES operating environment can cause significant variations in its energy response function, which may result in systematic errors in the absolute energy scale. We plan to monitor such changes at pixel level via onboard X-ray calibration sources and correct the energy scale accordingly using a linear or quadratic interpolation of gain curves obtained during ground calibration. However, this may not be sufficient to meet the 0.4 eV accuracy required for the X-IFU. In this contribution, we introduce a new two-parameter gain correction technique, based on both the pulse-height estimate of a fiducial line and the baseline value of the pixels. Using gain functions that simulate ground calibration data, we show that this technique can accurately correct deviations in detector gain due to changes in TES operating conditions such as heat sink temperature, bias voltage, thermal radiation loading and linear amplifier gain. We also address potential optimisations of the onboard calibration source and compare the performance of this new technique with those previously used.

Second-generation antipsychotic use in schizophrenia and associated weight gain: a critical review and meta-analysis of behavioral and pharmacologic treatments.

Science.gov (United States)

Das, Chandan; Mendez, Guillermo; Jagasia, Sonal; Labbate, Lawrence A

2012-08-01

Weight gain in schizophrenia, particularly secondary to second-generation antipsychotic (SGA) use, is a common adverse effect and often is associated with significant physical and psychological morbidity. We performed a critical literature review of all controlled clinical trials for pharmacologic and/or behavioral management of SGA-induced weight gain in schizophrenia patients by searching PubMed and Google Scholar. A meta-analysis was performed to estimate and compare weight changes for various medications and behavioral interventions. Sample sizes generally were small. Clinical trials were 6 weeks to 1 year, and weight loss was modest with any treatment. Although several adjunctive pharmacologic treatments showed no weight loss, sibutramine, metformin, and topiramate showed some benefit. Amantadine and orlistat were somewhat less effective and had lower rates of tolerability. Among the behavioral therapies, nutritional counseling combined with exercise showed the most benefit. Behavioral therapies, although modest, showed the most consistent benefits compared with controls. Scheduled pharmacologic treatment to prevent weight gain or promote weight loss in schizophrenia patients on SGA therapy is limited based on current studies. Switching antipsychotic agents has not been established as a long-term solution. Additional long-term studies are required to influence clinical practice.

Extinction Ratio and Gain Optimization of Dual- Pump Degenerate-Idler Phase Sensitive Amplifiers

DEFF Research Database (Denmark)

Kang, Ning; Lund-Hansen, Toke; Seoane, Jorge

2011-01-01

Numerical optimization of dual-pump degenerateidler phase sensitive amplifiers is performed for Al-doped and standard highly nonlinear fibers. Design considerations for operating the PSAs at an optimum combination of gain and extinction ratio are discussed.......Numerical optimization of dual-pump degenerateidler phase sensitive amplifiers is performed for Al-doped and standard highly nonlinear fibers. Design considerations for operating the PSAs at an optimum combination of gain and extinction ratio are discussed....

Gain beyond cosmesis: Demonstration of psychosocial and functional gains following successful strabismus surgery using the adult strabismus questionnaire adult strabismus 20

Directory of Open Access Journals (Sweden)

Danish Alam

2014-01-01

Full Text Available Background: Strabismus adversely affects psychosocial and functional aspects; while its correction impacts positively. Aim: The aim was to evaluate the gains in scores: Overall scores (OASs, psychosocial subscale scores (PSSs and functional subscale scores (FSSs following successful surgical alignment. Settings and Design: We evaluated changed scores in the adult strabismus 20 (AS-20 questionnaire, administered before and after successful surgery. Materials and Methods: Thirty adults horizontal strabismics, were administered the AS-20, at baseline, and at 6-week and 3-month. Group-wise analysis was carried out based on gender, strabismus type (esotropia [ET] or exotropia [XT], back-ground and amblyopia. Statistical Analysis: We used Wilcoxon, and Mann-Whitney U-tests. Significance was set at P ≤ 0.05. Results: At baseline, there were no significant differences within the groups, except that those with amblyopia significantly scored less than nonamblyopes in OAS (median scores: 53.8 vs. 71.3; P = 0.009 and FSS (56.3 vs. 85.3; P = 0.009. OAS, PSS and FSS showed significant gains at 6-week and 3-month (all Wilcoxon P < 0.001. Compared with males, females showed significantly more gain at 3-month (OAS: 37.9 vs. 28.7; P = 0.02, on account of PSS gain (49.6 vs. 37.5; P = 0.01. The ET performed better than XT only on the FSS at 6-week (28.7 vs. 15.0; P = 0.02. Vis-à-vis the nonamblyopes, the amblyopes showed significantly more benefit at 6-week alone (OAS: 18.7 vs. 28.7; P = 0.04, largely due to gains in PSS. Conclusions: Successful strabismus surgery has demonstrated significant gains in psychosocial, functional and overall functions. There is some evidence that gains may be more in females; with a trend to better outcomes in ET and amblyopes up to 6-week.

Demonstration Of 3D Effects With High Gain And Efficiency In A UV FEL Oscillator

International Nuclear Information System (INIS)

Benson, Stephen; Biallas, George; Blackburn, Keith; Boyce, James; Bullard, Donald; Coleman, James; Dickover, Cody; Douglas, David; Ellingsworth, Forrest; Evtushenko, Pavel; Hernandez-Garcia, Carlos; Gould, Christopher; Gubeli, Joseph; Hardy, David; Jordan, Kevin; Klopf, John; Kortze, James; Legg, Robert; Marchlik, Matthew; Moore, Steven; Neil, George; Powers, Thomas; Sexton, Daniel; Shinn, Michelle; Tennant, Christopher; Walker, Richard; Watson, Anne; Williams, Gwyn; Wilson, Frederick; Zhang, Shukui

2011-01-01

We report on the performance of a high gain UV FEL oscillator operating on an energy recovery linac at Jefferson Lab. The high brightness of the electron beam leads to both gain and efficiency that cannot be reconciled with a one-dimensional model. Three-dimensional simulations do predict the performance with reasonable precision. Gain in excess of 100% per pass and an efficiency close to 1/2NW, where NW is the number of wiggler periods, is seen. The laser mirror tuning curves currently permit operation in the wavelength range of 438 to 362 nm. Another mirror set allows operation at longer wavelengths in the red with even higher gain and efficiency.

Performance Evaluation and Requirements Assessment for Gravity Gradient Referenced Navigation

Directory of Open Access Journals (Sweden)

Jisun Lee

2015-07-01

Full Text Available In this study, simulation tests for gravity gradient referenced navigation (GGRN are conducted to verify the effects of various factors such as database (DB and sensor errors, flight altitude, DB resolution, initial errors, and measurement update rates on the navigation performance. Based on the simulation results, requirements for GGRN are established for position determination with certain target accuracies. It is found that DB and sensor errors and flight altitude have strong effects on the navigation performance. In particular, a DB and sensor with accuracies of 0.1 E and 0.01 E, respectively, are required to determine the position more accurately than or at a level similar to the navigation performance of terrain referenced navigation (TRN. In most cases, the horizontal position error of GGRN is less than 100 m. However, the navigation performance of GGRN is similar to or worse than that of a pure inertial navigation system when the DB and sensor errors are 3 E or 5 E each and the flight altitude is 3000 m. Considering that the accuracy of currently available gradiometers is about 3 E or 5 E, GGRN does not show much advantage over TRN at present. However, GGRN is expected to exhibit much better performance in the near future when accurate DBs and gravity gradiometer are available.

Active rc filter permits easy trade-off of amplifier gain and sensitivity to gain

Science.gov (United States)

Kerwin, W. J.; Shaffer, C. V.

1968-01-01

Passive RC network was designed with zeros of transmission in the right half of the complex frequency plane in the feedback loop of a simple negative-gain amplifier. The proper positioning provides any desired trade-off between amplifier gain and sensitivity to amplifier gain.

Novel Approach to Design Ultra Wideband Microwave Amplifiers: Normalized Gain Function Method

Directory of Open Access Journals (Sweden)

R. Kopru

2013-09-01

Full Text Available In this work, we propose a novel approach called as “Normalized Gain Function (NGF method” to design low/medium power single stage ultra wide band microwave amplifiers based on linear S parameters of the active device. Normalized Gain Function TNGF is defined as the ratio of T and |S21|^2, desired shape or frequency response of the gain function of the amplifier to be designed and the shape of the transistor forward gain function, respectively. Synthesis of input/output matching networks (IMN/OMN of the amplifier requires mathematically generated target gain functions to be tracked in two different nonlinear optimization processes. In this manner, NGF not only facilitates a mathematical base to share the amplifier gain function into such two distinct target gain functions, but also allows their precise computation in terms of TNGF=T/|S21|^2 at the very beginning of the design. The particular amplifier presented as the design example operates over 800-5200 MHz to target GSM, UMTS, Wi-Fi and WiMAX applications. An SRFT (Simplified Real Frequency Technique based design example supported by simulations in MWO (MicroWave Office from AWR Corporation is given using a 1400mW pHEMT transistor, TGF2021-01 from TriQuint Semiconductor.

Long-term weight gain and economic impact in pigs castrated under local anaesthesia

Directory of Open Access Journals (Sweden)

F.G. Telles

2016-12-01

Full Text Available Castration is a controversial practice in swine production because in some countries is still performed without anaesthesia, and therefore causes intense suffering and stress to animals. This study investigated the effect of pre-surgical administration of local anaesthesia (LA on the growth performance of piglets until the end of the growth phase (102 days. Piglets aged 3 to 5 days were selected in pairs of similar weights and same age. They were originated from 22 litters. The groups were randomly assigned to one of two treatments. Castration was performed with (LA; n = 45 or without (NLA; n = 45 intra-testicular administration of 0.5 mL of 2% lidocaine plus adrenaline per testicle, administered by an automatic repeating vaccinator. Castration was performed 10 min later. Average daily weight gain and economic impact were evaluated between the intervals before castration until 21 (weaning phase, before castration until 60 (end of the initial nursery phase and before castration until 102 (growth phase days of age. Average daily weight gain data were analyzed by comparing the average daily weight gain between the weaning phase, 60 and 102 days of age versus the initial weight (pre-castration. At the end of the growing phase, animals treated with LA showed greater weight gain than animals castrated without anaesthesia. LA also showed improved cost:benefit ratio and theore might provide greater economic benefit under the conditions used in this study. Our findings have proved that castration with LA improves long-term weight gain of piglets.

Luminescent solar concentrators with a bottom-mounted photovoltaic cell: performance optimization and power gain analysis

Institute of Scientific and Technical Information of China (English)

Ningning Zhang; Yi Zhang; Jun Bao; Feng Zhang; Sen Yan; Song Sun; Chen Gao

2017-01-01

Polymethyl methacrylate (PMMA) plate luminescent solar concentrators with a bottom-mounted (BM-LSCs) photovoltaic (PV) cell are fabricated by using a mixture of Lumogen Red 305 and Yellow 083 fluorescent dyes and a commercial monocrystalline silicon cell.The fabricated LSC with dye concentrations of 40 ppm has the highest power gain of 1.50,which is the highest value reported for the dye-doped PMMA plate LSCs.The power gain of the LSC comes from three parts:the waveguide light,the transmitted light,and the reflected light from a white reflector,and their contributions are analyzed quantitatively.The results suggest that the BM-LSCs have great potential for future low-cost PV devices in building integrated PV applications.

Low Gain Avalanche Detectors (LGAD) for particle physics and synchrotron applications

Science.gov (United States)

Moffat, N.; Bates, R.; Bullough, M.; Flores, L.; Maneuski, D.; Simon, L.; Tartoni, N.; Doherty, F.; Ashby, J.

2018-03-01

A new avalanche silicon detector concept is introduced with a low gain in the region of ten, known as a Low Gain Avalanche Detector, LGAD. The detector's characteristics are simulated via a full process simulation to obtain the required doping profiles which demonstrate the desired operational characteristics of high breakdown voltage (500 V) and a gain of 10 at 200 V reverse bias for X-ray detection. The first low gain avalanche detectors fabricated by Micron Semiconductor Ltd are presented. The doping profiles of the multiplication junctions were measured with SIMS and reproduced by simulating the full fabrication process which enabled further development of the manufacturing process. The detectors are 300 μm thick p-type silicon with a resistivity of 8.5 kΩcm, which fully depletes at 116 V. The current characteristics are presented and demonstrate breakdown voltages in excess of 500 V and a current density of 40 to 100 nAcm‑2 before breakdown measured at 20oC. The gain of the LGAD has been measured with a red laser (660 nm) and shown to be between 9 and 12 for an external bias voltage range from 150 V to 300 V.

Energy Requirements in Early Life Are Similar for Male and Female Goat Kids

Directory of Open Access Journals (Sweden)

T. F. V. Bompadre

2014-12-01

Full Text Available Little is known about the gender differences in energetic requirements of goats in early life. In this study, we determined the energy requirements for maintenance and gain in intact male, castrated male and female Saanen goat kids using the comparative slaughter technique and provide new data on their body composition and energy efficiency. To determine the energy requirements for maintenance, we studied 21 intact males, 15 castrated males and 18 females (5.0±0.1 kg initial body weight (BW and 23±5 d of age using a split-plot design with the following main factors: three genders (intact males, castrated males, and females and three dry matter intake levels (ad libitum, 75% and 50% of ad libitum intake. A slaughter group included three kids, one for each nutritional plane, of each gender, and all three animals within a group were slaughtered when the ad libitum kid reached 15 kg in BW. Net energy requirements for gain were obtained for 17 intact males, eight castrated males and 15 females (5.1±0.4 kg BW and 23±13 d of age. Animals were fed ad libitum and slaughtered when they reached 5, 10, and 15 kg in BW. A digestion trial was performed with nine kids of each gender to determine digestible energy, metabolizable energy and energy metabolizability of the diet. Our results show no effect of gender on the energy requirements for maintenance and gain, and overall net energy for maintenance was 205.6 kJ/kg0.75 empty body weight gain (EBW (170.3 kJ/kg0.75 BW from 5 to 15 kg BW. Metabolizable energy for maintenance was calculated by iteration, assuming heat production equal to metabolizable energy intake at maintenance, and the result was 294.34 kJ/kg0.75 EBW and km of 0.70. As BW increased from 5 to 15 kg for all genders, the net energy required for gain increased from 9.5 to 12.0 kJ/g EBW gain (EWG, and assuming kg = 0.47, metabolizable energy for gain ranged from 20.2 to 25.5 kJ/g EWG. Our results indicate that it is not necessary to formulate

An output amplitude configurable wideband automatic gain control with high gain step accuracy

International Nuclear Information System (INIS)

He Xiaofeng; Ye Tianchun; Mo Taishan; Ma Chengyan

2012-01-01

An output amplitude configurable wideband automatic gain control (AGC) with high gain step accuracy for the GNSS receiver is presented. The amplitude of an AGC is configurable in order to cooperate with baseband chips to achieve interference suppression and be compatible with different full range ADCs. And what's more, the gain-boosting technology is introduced and the circuit is improved to increase the step accuracy. A zero, which is composed by the source feedback resistance and the source capacity, is introduced to compensate for the pole. The AGC is fabricated in a 0.18 μm CMOS process. The AGC shows a 62 dB gain control range by 1 dB each step with a gain error of less than 0.2 dB. The AGC provides 3 dB bandwidth larger than 80 MHz and the overall power consumption is less than 1.8 mA, and the die area is 800 × 300 μm 2 . (semiconductor integrated circuits)

Adaptive gain modulation in V1 explains contextual modifications during bisection learning.

Directory of Open Access Journals (Sweden)

Roland Schäfer

2009-12-01

Full Text Available The neuronal processing of visual stimuli in primary visual cortex (V1 can be modified by perceptual training. Training in bisection discrimination, for instance, changes the contextual interactions in V1 elicited by parallel lines. Before training, two parallel lines inhibit their individual V1-responses. After bisection training, inhibition turns into non-symmetric excitation while performing the bisection task. Yet, the receptive field of the V1 neurons evaluated by a single line does not change during task performance. We present a model of recurrent processing in V1 where the neuronal gain can be modulated by a global attentional signal. Perceptual learning mainly consists in strengthening this attentional signal, leading to a more effective gain modulation. The model reproduces both the psychophysical results on bisection learning and the modified contextual interactions observed in V1 during task performance. It makes several predictions, for instance that imagery training should improve the performance, or that a slight stimulus wiggling can strongly affect the representation in V1 while performing the task. We conclude that strengthening a top-down induced gain increase can explain perceptual learning, and that this top-down signal can modify lateral interactions within V1, without significantly changing the classical receptive field of V1 neurons.

Determinants of Cattle Feeding Profit and Cost of Gain Variability

OpenAIRE

Schroeder, Ted C.; Albright, Martin L.; Langemeier, Michael R.; Mintert, James R.

1993-01-01

Cattle feeders face risks from fluctuating fed cattle, feeder cattle, and feed prices and cattle performance. Closeout data on 7293 pens of steers are studied to determine the relative impacts of prices and animal performance on cattle feeding profits and cost of gain. Results indicate the importance of managing price risk.

High-Performance 1.55-µm Superluminescent Diode Based on Broad Gain InAs/InGaAlAs/InP Quantum Dash Active Region

KAUST Repository

Khan, Mohammed Zahed Mustafa

2014-08-01

We report on the high-performance characteristics from superluminescent diodes (SLDs) based on four-stack InAs/InGaAlAs chirped-barrier thickness quantum dash (Qdash) in a well structure. The active region exhibits a measured broad gain spectrum of 140 nm, with a peak modal gain of ~41 cm-1. The noncoated two-section gainabsorber broad-area and ridge-waveguide device configuration exhibits an output power of > 20 mW and > 12 mW, respectively. The corresponding -3-dB bandwidths span ~82 nm and ~72 nm, with a small spectral ripple of <; 0.2 dB, related largely to the contribution from dispersive height dash ensembles of the highly inhomogeneous active region. These C-L communication band devices will find applications in various cross-disciplinary fields of optical metrology, optical coherent tomography, etc.

Management intensity and genetics affect loblolly pine seedling performance

Science.gov (United States)

Scott D. Roberts; Randall J. Rousseau; B. Landis Herrin

2012-01-01

Capturing potential genetic gains from tree improvement programs requires selection of the appropriate genetic stock and application of appropriate silvicultural management techniques. Limited information is available on how specific loblolly pine varietal genotypes perform under differing growing environments and management approaches. This study was established in...

Comparison of exertion required to perform standard and active compression-decompression cardiopulmonary resuscitation.

Science.gov (United States)

Shultz, J J; Mianulli, M J; Gisch, T M; Coffeen, P R; Haidet, G C; Lurie, K G

1995-02-01

Active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) utilizes a hand-held suction device with a pressure gauge that enables the operator to compress as well as actively decompress the chest. This new CPR method improves hemodynamic and ventilatory parameters when compared with standard CPR. ACD-CPR is easy to perform but may be more labor intensive. The purpose of this study was to quantify and compare the work required to perform ACD and standard CPR. Cardiopulmonary testing was performed on six basic cardiac life support- and ACD-trained St. Paul, MN fire-fighter personnel during performance of 10 min each of ACD and standard CPR on a mannequin equipped with a compression gauge. The order of CPR techniques was determined randomly with > 1 h between each study. Each CPR method was performed at 80 compressions/min (timed with a metronome), to a depth of 1.5-2 inches, and with a 50% duty cycle. Baseline cardiopulmonary measurements were similar at rest prior to performance of both CPR methods. During standard and ACD-CPR, respectively, rate-pressure product was 18.2 +/- 3.0 vs. 23.8 +/- 1.7 (x 1000, P CPR compared with standard CPR. Both methods require subanaerobic energy expenditure and can therefore be sustained for a sufficient length of time by most individuals to optimize resuscitation efforts. Due to the slightly higher work requirement, ACD-CPR may be more difficult to perform compared with standard CPR for long periods of time, particularly by individuals unaccustomed to the workload requirement of CPR, in general.

Gain attenuation of gated framing camera

International Nuclear Information System (INIS)

Xiao Shali; Liu Shenye; Cao Zhurong; Li Hang; Zhang Haiying; Yuan Zheng; Wang Liwei

2009-01-01

The theoretic model of framing camera's gain attenuation is analyzed. The exponential attenuation curve of the gain along the pulse propagation time is simulated. An experiment to measure the coefficient of gain attenuation based on the gain attenuation theory is designed. Experiment result shows that the gain follows an exponential attenuation rule with a quotient of 0.0249 nm -1 , the attenuation coefficient of the pulse is 0.00356 mm -1 . The loss of the pulse propagation along the MCP stripline is the leading reason of gain attenuation. But in the figure of a single stripline, the gain dose not follow the rule of exponential attenuation completely, instead, there is a gain increase at the stripline bottom. That is caused by the reflection of the pulse. The reflectance is about 24.2%. Combining the experiment and theory, which design of the stripline MCP can improved the gain attenuation. (authors)

Large Signal Circuit Model of Two-Section Gain Lever Quantum Dot Laser

International Nuclear Information System (INIS)

Horri Ashkan; Mirmoeini Seyedeh Zahra; Faez Rahim

2012-01-01

An equivalent circuit model for the design and analysis of two-section gain lever quantum dot (QD) laser is presented. This model is based on the three level rate equations with two independent carrier populations and a single longitudinal optical mode. By using the presented model, the effect of gain lever on QD laser performances is investigated. The results of simulation show that the main characteristics of laser such as threshold current, transient response, output power and modulation response are affected by differential gain ratios between the two-sections

The Effect Feed Supplement of Medicated Block (SPMB) of the Daily Weight Gain on Cows after Calving

International Nuclear Information System (INIS)

Suharyono; Andini, L.S; WT Sasongko

2004-01-01

The purpose of the experiment was to develop feed supplement for sustain ability of technology and improving the performance of cows after calving. This feed supplement is derived from modification of UMMB-bungkil kedelai composition. In vitro study to measure ratio bacteria and protozoa using 32 P method was carried out. Cows after calving were treated 3 with treatments, namely I = control (basal diet + concentrate), II = I + UMMB, III = I + SPMB-temu ireng. Ratio bacteria and protozoa of UMMB-soy bean powder and soy bean meal was 19:1 and 14:1 respectively. Nutrient content of crude protein was 30.02 and 26.47%. SPMB-temu ireng and UMMB increased daily weight gain of cows 0.02 and 0.01 kg/h/d compared control (0.08 kg/h/d). The daily weight gain decreased, however, it was slower than control. The daily weight gain was - 0.04 and - 0.03 kg/h/d compared to - 0.3 kg/h/d. Basal diet and concentrate offered in Gunungkidul was between 5.4 - 6.84 forages/DM and 1.7 - 3.3 kg, while in Sleman it was 5.2 - 5.81 kg/forages/DM and 2.5 - 3.2 kg. The overall conclusion is the SPMB and UMMB has positive responds on the performance of cows after calving, however, the cows have to be fulfilled with the requirement of basal diet. (author)

Amplifying mirrors with saturated gain without and with a resonator

DEFF Research Database (Denmark)

Skettrup, Torben

2007-01-01

An investigation of amplifying mirrors with a view to their use in resonator structures has been performed. Both non-saturated and saturated amplifying mirrors are demonstrated. It was found that relatively high values of gain (typical 5-10 times) can be obtained even when saturation is taken...... into account. Several resonator structures containing from two up to four mirrors, some including beamsplitters, are investigated. It was found that the gain to a first approximation depends only on the ratio between the pumping power and the input power on the amplifying mirror. It was also found...... that the configuration with four mirrors is well suited as an amplifier device working as an optical transistor since high values of gain up to 40 times could be obtained....

Measurements and modeling of gain coefficients for neodymium laser glasses

International Nuclear Information System (INIS)

Linford, G.J.; Saroyan, R.A.; Trenholme, J.B.; Weber, M.J.

1979-01-01

Small-signal gain coefficients are reported for neodymium in silicate, phosphate, fluorophosphate, and fluoroberyllate laser glasses. Measurements were made in a disk amplifier under identical conditions. Using spectroscopic data as the input, amplifier gain is calculated as a fucntion of flashlamp energy, pumping pulse duration, disk thickness, and Nd-doping. The agreement between predicted and measured gains is generally with ;plus or minus;10 percent, consistent with experimental uncertainties in the model and the parameters used. The operating conditions which optimize amplifier performance and efficiency for a given laser glass may be found using spectroscopic data alone. This process can be extended to derive the most cost-effective staging of amplifier chains for fusion lasers. A discussion of the model and examples of calculations are presented

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 ...

Magnetically coupled high-gain Y-source isolated DC/DC converter

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

2014-01-01

A new form of magnetically coupled DC/DC converter is proposed for medium power applications (250 W to 2 kW), requiring a high-voltage gain, short inductive charging time and galvanic isolation. The proposed converter can be realised using a unique Y-source impedance network and a two-switch push...

Adaptive Neuro-Fuzzy Based Gain Controller for Erbium-Doped Fiber Amplifiers

Directory of Open Access Journals (Sweden)

YUCEL, M.

2017-02-01

Full Text Available Erbium-doped fiber amplifiers (EDFA must have a flat gain profile which is a very important parameter such as wavelength division multiplexing (WDM and dense WDM (DWDM applications for long-haul optical communication systems and networks. For this reason, it is crucial to hold a stable signal power per optical channel. For the purpose of overcoming performance decline of optical networks and long-haul optical systems, the gain of the EDFA must be controlled for it to be fixed at a high speed. In this study, due to the signal power attenuation in long-haul fiber optic communication systems and non-equal signal amplification in each channel, an automatic gain controller (AGC is designed based on the adaptive neuro-fuzzy inference system (ANFIS for EDFAs. The intelligent gain controller is implemented and the performance of this new electronic control method is demonstrated. The proposed ANFIS-based AGC-EDFA uses the experimental dataset to produce the ANFIS-based sets and the rule base. Laser diode currents are predicted within the accuracy rating over 98 percent with the proposed ANFIS-based system. Upon comparing ANFIS-based AGC-EDFA and experimental results, they were found to be very close and compatible.

Active Enhancement of Slow Light Based on Plasmon-Induced Transparency with Gain Materials.

Science.gov (United States)

Zhang, Zhaojian; Yang, Junbo; He, Xin; Han, Yunxin; Zhang, Jingjing; Huang, Jie; Chen, Dingbo; Xu, Siyu

2018-06-03

As a plasmonic analogue of electromagnetically induced transparency (EIT), plasmon-induced transparency (PIT) has drawn more attention due to its potential of realizing on-chip sensing, slow light and nonlinear effect enhancement. However, the performance of a plasmonic system is always limited by the metal ohmic loss. Here, we numerically report a PIT system with gain materials based on plasmonic metal-insulator-metal waveguide. The corresponding phenomenon can be theoretically analyzed by coupled mode theory (CMT). After filling gain material into a disk cavity, the system intrinsic loss can be compensated by external pump beam, and the PIT can be greatly fueled to achieve a dramatic enhancement of slow light performance. Finally, a double-channel enhanced slow light is introduced by adding a second gain disk cavity. This work paves way for a potential new high-performance slow light device, which can have significant applications for high-compact plasmonic circuits and optical communication.

Effect of massage stimulation on weight gain in full term infants

Directory of Open Access Journals (Sweden)

Nyoman Nursari Dewi

2011-08-01

Full Text Available Background Massage is a tactile/kinesthetic stimulation with biochemical and physiological effects on the body. Newborn infant massage stimulation given by mothers may promote maternal-infant bonding and attachment, enhance infant weight gain and stimulate the production of breast milk. There have been few studies on the effect of massage stimulation on weight gain in full term infants, and this topic remains controversial. Objective To examine the effect of massage stimulation on weight gain in full term infants. Methods This quasi-experimental study was held in Sanglah Hospital and Bunda Setia Maternity Clinic. Massage stimulation was performed by mothers once daily for a four week period. Massage stimulation was given to 30 full term infants and their weight gain was compared to 31 control infants who did not receive massages. Results There were no differences in subject characteristics between the massage and control groups. Median weight gain in the massage group was 1230 grams, while that in the control group was 830 grams (P=0.028. Conclusion Weight gain in full term infants in the massage group was significantly greater than that in the control group after 4 weeks.

Summary of Pressure Gain Combustion Research at NASA

Science.gov (United States)

Perkins, H. Douglas; Paxson, Daniel E.

2018-01-01

NASA has undertaken a systematic exploration of many different facets of pressure gain combustion over the last 25 years in an effort to exploit the inherent thermodynamic advantage of pressure gain combustion over the constant pressure combustion process used in most aerospace propulsion systems. Applications as varied as small-scale UAV's, rotorcraft, subsonic transports, hypersonics and launch vehicles have been considered. In addition to studying pressure gain combustor concepts such as wave rotors, pulse detonation engines, pulsejets, and rotating detonation engines, NASA has studied inlets, nozzles, ejectors and turbines which must also process unsteady flow in an integrated propulsion system. Other design considerations such as acoustic signature, combustor material life and heat transfer that are unique to pressure gain combustors have also been addressed in NASA research projects. In addition to a wide range of experimental studies, a number of computer codes, from 0-D up through 3-D, have been developed or modified to specifically address the analysis of unsteady flow fields. Loss models have also been developed and incorporated into these codes that improve the accuracy of performance predictions and decrease computational time. These codes have been validated numerous times across a broad range of operating conditions, and it has been found that once validated for one particular pressure gain combustion configuration, these codes are readily adaptable to the others. All in all, the documentation of this work has encompassed approximately 170 NASA technical reports, conference papers and journal articles to date. These publications are very briefly summarized herein, providing a single point of reference for all of NASA's pressure gain combustion research efforts. This documentation does not include the significant contributions made by NASA research staff to the programs of other agencies, universities, industrial partners and professional society

Substrate effects in high gain, low operating voltage SnSe2 photoconductor

Science.gov (United States)

Krishna, Murali; Kallatt, Sangeeth; Majumdar, Kausik

2018-01-01

High gain photoconductive devices find wide spread applications in low intensity light detection. Ultra-thin layered materials have recently drawn a lot of attention from researchers in this regard. However, in general, a large operating voltage is required to obtain large responsivity in these devices. In addition, the characteristics are often confounded by substrate induced trap effects. Here we report multi-layer SnSe2 based photoconductive devices using two different structures: (1) SiO2 substrate supported inter-digitated electrode (IDE), and (2) suspended channel. The IDE device exhibits a responsivity of ≈ {10}3 A W-1 and ≈ 8.66× {10}4 A W-1 at operating voltages of 1 mV and 100 mV, respectively—a superior low voltage performance over existing literature on planar 2D structures. However, the responsivity reduces by more than two orders of magnitude, while the transient response improves for the suspended device—providing insights into the critical role played by the channel-substrate interface in the gain mechanism. The results, on one hand, are promising for highly sensitive photoconductive applications consuming ultra-low power, and on the other hand, show a generic methodology that could be applied to other layered material based photoconductive devices as well for extracting the intrinsic behavior.

The influence of age-group structure on genetic gain and ...

African Journals Online (AJOL)

51 to 69 between different herds and cowage-group struc- tures. All three herds required at ... Keywords: Age-group structure, genetic gain, productivity, beef cattle ... 2160 to 210 898 during the same period (Hofmeyr, 1978 and. Bosman, 1982). .... Using the information in Figure 1to determine the reproduc- tion rate of herds ...

40 CFR 158.2070 - Biochemical pesticides product performance data requirements.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Biochemical pesticides product performance data requirements. 158.2070 Section 158.2070 Protection of Environment ENVIRONMENTAL PROTECTION... efficacy data unless the pesticide product bears a claim to control public health pests, such as pest...

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…

National proficiency-gain curves for minimally invasive gastrointestinal cancer surgery.

Science.gov (United States)

Mackenzie, H; Markar, S R; Askari, A; Ni, M; Faiz, O; Hanna, G B

2016-01-01

Minimal access surgery for gastrointestinal cancer has short-term benefits but is associated with a proficiency-gain curve. The aim of this study was to define national proficiency-gain curves for minimal access colorectal and oesophagogastric surgery, and to determine the impact on clinical outcomes. All adult patients undergoing minimal access oesophageal, colonic and rectal surgery between 2002 and 2012 were identified from the Hospital Episode Statistics database. Proficiency-gain curves were created using risk-adjusted cumulative sum analysis. Change points were identified, and bootstrapping was performed with 1000 iterations to identify a confidence level. The primary outcome was 30-day mortality; secondary outcomes were 90-day mortality, reintervention, conversion and length of hospital stay. Some 1696, 15 008 and 16 701 minimal access oesophageal, rectal and colonic cancer resections were performed during the study period. The change point in the proficiency-gain curve for 30-day mortality for oesophageal, rectal and colonic surgery was 19 (confidence level 98·4 per cent), 20 (99·2 per cent) and three (99·5 per cent) procedures; the mortality rate fell from 4·0 to 2·0 per cent (relative risk reduction (RRR) 0·50, P = 0·033), from 2·1 to 1·2 per cent (RRR 0·43, P curve for reintervention in oesophageal, rectal and colonic resection was 19 (98·1 per cent), 32 (99·5 per cent) and 26 (99·2 per cent) procedures respectively. There were also significant proficiency-gain curves for 90-day mortality, conversion and length of stay. The introduction of minimal access gastrointestinal cancer surgery has been associated with a proficiency-gain curve for mortality and major morbidity at a national level. Unnecessary patient harm should be avoided by appropriate training and monitoring of new surgical techniques. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.

Can Beta Blockers Cause Weight Gain?

Science.gov (United States)

... cause weight gain? Can beta blockers cause weight gain? Answers from Sheldon G. Sheps, M.D. Yes. Weight gain can occur as a side effect of some ... and metoprolol (Lopressor, Toprol-XL). The average weight gain is about 2.6 pounds (about 1.2 ...

Robust Optimal Adaptive Control Method with Large Adaptive Gain

Science.gov (United States)

Nguyen, Nhan T.

2009-01-01

In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

Estimating the potential gains from mergers

DEFF Research Database (Denmark)

Bogetoft, Peter; Wang, Dexiang

2005-01-01

We introduce simple production economic models to estimate the potential gains from mergers. We decompose the gains into technical ef¿ciency, size (scale) and harmony (mix) gains, and we discuss alternative ways to capture these gains. We propose to approximate the production processes using...... the non-parametric. Data Envelopment Analysis (DEA) approach, and we use the resulting operational approach to estimate the potential gains from merging agricultural extension of¿ces in Denmark....

Neuronal gain modulability is determined by dendritic morphology: A computational optogenetic study.

Science.gov (United States)

Jarvis, Sarah; Nikolic, Konstantin; Schultz, Simon R

2018-03-01

The mechanisms by which the gain of the neuronal input-output function may be modulated have been the subject of much investigation. However, little is known of the role of dendrites in neuronal gain control. New optogenetic experimental paradigms based on spatial profiles or patterns of light stimulation offer the prospect of elucidating many aspects of single cell function, including the role of dendrites in gain control. We thus developed a model to investigate how competing excitatory and inhibitory input within the dendritic arbor alters neuronal gain, incorporating kinetic models of opsins into our modeling to ensure it is experimentally testable. To investigate how different topologies of the neuronal dendritic tree affect the neuron's input-output characteristics we generate branching geometries which replicate morphological features of most common neurons, but keep the number of branches and overall area of dendrites approximately constant. We found a relationship between a neuron's gain modulability and its dendritic morphology, with neurons with bipolar dendrites with a moderate degree of branching being most receptive to control of the gain of their input-output relationship. The theory was then tested and confirmed on two examples of realistic neurons: 1) layer V pyramidal cells-confirming their role in neural circuits as a regulator of the gain in the circuit in addition to acting as the primary excitatory neurons, and 2) stellate cells. In addition to providing testable predictions and a novel application of dual-opsins, our model suggests that innervation of all dendritic subdomains is required for full gain modulation, revealing the importance of dendritic targeting in the generation of neuronal gain control and the functions that it subserves. Finally, our study also demonstrates that neurophysiological investigations which use direct current injection into the soma and bypass the dendrites may miss some important neuronal functions, such as gain

42 CFR 457.710 - State plan requirements: Strategic objectives and performance goals.

Science.gov (United States)

2010-10-01

.... The State's strategic objectives, performance goals and performance measures must include a common... 42 Public Health 4 2010-10-01 2010-10-01 false State plan requirements: Strategic objectives and...) ALLOTMENTS AND GRANTS TO STATES Strategic Planning, Reporting, and Evaluation § 457.710 State plan...

WELFARE GAIN FROM CARBON TAX APPLIED TO LEISURE AIR TRAFFIC

Directory of Open Access Journals (Sweden)

Roberto Rendeiro Martín-Cejas

2017-12-01

Full Text Available ABSTRACTThe rapid growth in the air transport required satisfying the increased demand for tourism become a factor of unsustainability due to the substantial environmental impact that supports such a development. There is the need to establish an alternative to the traditional air transport pricing structure that reflects the true cost that air market operators impose on others. This paper analyses one application of a Carbon tax by considering the CO2 emission costs as a valuable input. A tentative tax on CO2 emissions from air transport is calculated considering its applications in leisure air transport market. Finally, one of the main conclusions of the analysis performed is that the available evidence suggests that international aviation emissions should be restricted. In this case, a Ramsey pricing structure, which involved aviation users bearing the environmental costs, would work reasonably well at restricting inefficient demand and produce a reasonable welfare gain respect to the do-nothing scenerywill be pointed out.

A Gain-Scheduling PI Control Based on Neural Networks

Directory of Open Access Journals (Sweden)

Stefania Tronci

2017-01-01

Full Text Available This paper presents a gain-scheduling design technique that relies upon neural models to approximate plant behaviour. The controller design is based on generic model control (GMC formalisms and linearization of the neural model of the process. As a result, a PI controller action is obtained, where the gain depends on the state of the system and is adapted instantaneously on-line. The algorithm is tested on a nonisothermal continuous stirred tank reactor (CSTR, considering both single-input single-output (SISO and multi-input multi-output (MIMO control problems. Simulation results show that the proposed controller provides satisfactory performance during set-point changes and disturbance rejection.

Effort, performance, and motivation: insights from robot-assisted training of human golf putting and rat grip strength.

Science.gov (United States)

Duarte, Jaime E; Gebrekristos, Berkenesh; Perez, Sergi; Rowe, Justin B; Sharp, Kelli; Reinkensmeyer, David J

2013-06-01

Robotic devices can modulate success rates and required effort levels during motor training, but it is unclear how this affects performance gains and motivation. Here we present results from training unimpaired humans in a virtual golf-putting task, and training spinal cord injured (SCI) rats in a grip strength task using robotically modulated success rates and effort levels. Robotic assistance in golf practice increased trainees feelings of competence, and, paradoxically, increased their sense effort, even though it had mixed effects on learning. Reducing effort during a grip strength training task led rats with SCI to practice the task more frequently. However, the more frequent practice of these rats did not cause them to exceed the strength gains achieved by rats that exercised less often at higher required effort levels. These results show that increasing success and decreasing effort with robots increases motivation, but has mixed effects on performance gains.

The order of information processing alters economic gain-loss framing effects.

Science.gov (United States)

Kwak, Youngbin; Huettel, Scott

2018-01-01

Adaptive decision making requires analysis of available information during the process of choice. In many decisions that information is presented visually - which means that variations in visual properties (e.g., salience, complexity) can potentially influence the process of choice. In the current study, we demonstrate that variation in the left-right positioning of risky and safe decision options can influence the canonical gain-loss framing effect. Two experiments were conducted using an economic framing task in which participants chose between gambles and certain outcomes. The first experiment demonstrated that the magnitude of the gain-loss framing effect was greater when the certain option signaling the current frame was presented on the left side of the visual display. Eye-tracking data during task performance showed a left-gaze bias for initial fixations, suggesting that the option presented on the left side was processed first. Combination of eye-tracking and choice data revealed that there was a significant effect of direction of first gaze (i.e. left vs. right) as well as an interaction between gaze direction and identity of the first fixated information (i.e. certain vs. gamble) regardless of frame. A second experiment presented the gamble and certain options in a random order, with a temporal delay between their presentations. We found that the magnitude of gain-loss framing was larger when the certain option was presented first, regardless of left and right positioning, only in individuals with lower risk-taking tendencies. The effect of presentation order on framing was not present in high risk-takers. These results suggest that the sequence of visual information processing as well as their left-right positioning can bias choices by changing the impact of the presented information during risky decision making. Copyright © 2017 Elsevier B.V. All rights reserved.

Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

Science.gov (United States)

Čeko, Marta; Gracely, John L.; Fitzcharles, Mary-Ann; Seminowicz, David A.; Schweinhardt, Petra

2015-01-01

In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or “negative” [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether a responsive DMN is required for successful cognitive performance, we compared healthy human subjects (n = 23) with individuals shown to have decreased DMN engagement (chronic pain patients, n = 28). Subjects performed a multilevel working-memory task (N-back) during fMRI. If a responsive DMN is required for successful performance, patients having reduced DMN responsiveness should show worsened performance; if performance is not reduced, their brains should show compensatory activation in external-task-positive regions or elsewhere. All subjects showed decreased accuracy and increased reaction times with increasing task level, with no significant group differences on either measure at any level. Patients had significantly reduced negative fMRI response (deactivation) of DMN regions (posterior cingulate/precuneus, medial prefrontal cortex). Controls showed expected modulation of DMN deactivation with increasing task difficulty. Patients showed significantly reduced modulation of DMN deactivation by task difficulty, despite their successful task performance. We found no evidence of compensatory neural recruitment in external-task-positive regions or elsewhere. Individual responsiveness of the external-task-positive ventrolateral prefrontal cortex, but not of DMN regions, correlated with task accuracy. These findings suggest that a responsive DMN may not be required for successful cognitive performance; a responsive external-task-positive network may be sufficient

arXiv Simulation of gain stability of THGEM gas-avalanche particle detectors

CERN Document Server

Correia, P.M.M.; Azevedo, C.D.R.; Breskin, A.; Bressler, S.; Oliveira, C.A.B.; Silva, A.L.M.; Veenhof, R.; Veloso, J.F.C.A.

2018-01-19

Charging-up processes affecting gain stability in Thick Gas Electron Multipliers (THGEM) were studied with a dedicated simulation toolkit. Integrated with Garfield++, it provides an effective platform for systematic phenomenological studies of charging-up processes in MPGD detectors. We describe the simulation tool and the fine-tuning of the step-size required for the algorithm convergence, in relation to physical parameters. Simulation results of gain stability over time in THGEM detectors are presented, exploring the role of electrode-thickness and applied voltage on its evolution. The results show that the total amount of irradiated charge through electrode's hole needed for reaching gain stabilization is in the range of tens to hundreds of pC, depending on the detector geometry and operational voltage. These results are in agreement with experimental observations presented previously.

A gain-coefficient switched Alexandrite laser

International Nuclear Information System (INIS)

Lee, Chris J; Van der Slot, Peter J M; Boller, Klaus-J

2013-01-01

We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.

Measurement bias dependence of enhanced bipolar gain degradation at low dose rates

International Nuclear Information System (INIS)

Witczak, S.C.; Lacoe, R.C.; Mayer, D.C.; Fleetwood, D.M.

1998-03-01

Oxide trapped charge, field effects from emitter metallization, and high level injection phenomena moderate enhanced gain degradation of lateral pnp transistors at low dose rates. Hardness assurance tests at elevated irradiation temperatures require larger design margins for low power measurement biases

45 CFR 2516.810 - What types of evaluations are grantees and subgrantees required to perform?

Science.gov (United States)

2010-10-01

... Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE SCHOOL-BASED SERVICE-LEARNING PROGRAMS...? All grantees and subgrantees are required to perform internal evaluations which are ongoing efforts to assess performance and improve quality. Grantees and subgrantees may, but are not required to, arrange...

75 FR 37712 - Automatic Dependent Surveillance-Broadcast (ADS-B) Out Performance Requirements To Support Air...

Science.gov (United States)

2010-06-30

... Performance Requirements To Support Air Traffic Control (ATC) Service; Technical Amendment AGENCY: Federal... FAA amended its regulations to add equipage requirements and performance standards for Automatic... Approval for deviation was renumbered as Sec. 21.618, effective April 14, 2010. On May 28, 2010, the FAA...

GEM: Performance and aging tests

International Nuclear Information System (INIS)

Cho, H.S.; Kadyk, J.; Han, S.H.; Hong, W.S.; Perez-Mendez, V.; Wenzel, W.; Pitts, K.; Martin, M.D.; Hutchins, J.B.

1999-01-01

Performance and aging tests have been done to characterize Gas Electron Multipliers (GEMs), including further design improvements such as a thicker GEM and a closed GEM. Since the effective GEM gain is typically smaller than the absolute GEM gain, due to trapping of avalanche electrons at the bottom GEM electrode, the authors performed field simulations and measurements for better understanding, and discuss methods to eliminate this effect. Other performance parameters of the GEMs are also presented, including absolute GEM gain, short-term and long-term gain stabilities

Weight gain following treatment of hyperthyroidism.

Science.gov (United States)

Dale, J; Daykin, J; Holder, R; Sheppard, M C; Franklyn, J A

2001-08-01

Patients frequently express concern that treating hyperthyroidism will lead to excessive weight gain. This study aimed to determine the extent of, and risk factors for, weight gain in an unselected group of hyperthyroid patients. We investigated 162 consecutive hyperthyroid patients followed for at least 6 months. Height, weight, clinical features, biochemistry and management were recorded at each clinic visit. Documented weight gain was 5.42 +/- 0.46 kg (mean +/- SE) and increase in BMI was 8.49 +/- 0.71%, over a mean 24.2 +/- 1.6 months. Pre-existing obesity, Graves' disease causing hyperthyroidism, weight loss before presentation and length of follow-up each independently predicted weight gain. Patients treated with thionamides or radioiodine gained a similar amount of weight (thionamides, n = 87, 5.16 +/- 0.63 kg vs. radioiodine, n = 62, 4.75 +/- 0.57 kg, P = 0.645), but patients who underwent thyroidectomy (n = 13) gained more weight (10.27 +/- 2.56 kg vs. others, P = 0.007). Development of hypothyroidism (even transiently) was associated with weight gain (never hypothyroid, n = 102, 4.57 +/- 0.52 kg, transiently hypothyroid, n = 29, 5.37 +/- 0.85 kg, on T4, n = 31, 8.06 +/- 1.42 kg, P = 0.014). This difference remained after correcting for length of follow-up. In the whole cohort, weight increased by 3.95 +/- 0.40 kg at 1 year (n = 144) to 9.91 +/- 1.62 kg after 4 years (n = 27) (P = 0.008), representing a mean weight gain of 3.66 +/- 0.44 kg/year. We have demonstrated marked weight gain after treatment of hyperthyroidism. Pre-existing obesity, a diagnosis of Graves' disease and prior weight loss independently predicted weight gain and weight continued to rise with time. Patients who became hypothyroid, despite T4 replacement, gained most weight.

Broadband tunability of gain-flattened quantum-well semiconductor lasers with an external grating

International Nuclear Information System (INIS)

Mittelstein, M.; Mehuys, D.; Yariv, A.; Sarfaty, R.; Ungar, J.E.

1989-01-01

Semiconductor injection lasers are known to be tunable over a range of order kΒ · T. Quantum-well lasers, in particular, are shown to exhibit flattened, broadband gain spectra at a particular pumping condition. The gain requirement for a grating-tuned external cavity configuration is examined and is applied to a semiconductor quantum-well laser with an optimized length of gain region. The coupled-cavity formalism is employed to examine the conditions for continuous tuning. The possible tuning range of double-heterostructure lasers is compared to that of quantum-well lasers. The predicted broadband tunability of quantum-well lasers is confirmed experimentally by grating-tuning of uncoated lasers exceeding 120 nm, with single, longitudinal mode output power exceeding 300 mW

78 FR 38555 - Importer Permit Requirements for Tobacco Products and Processed Tobacco, and Other Requirements...

Science.gov (United States)

2013-06-27

..., and Other Requirements for Tobacco Products, Processed Tobacco, and Cigarette Papers and Tubes AGENCY... administration and enforcement of importer permits over the past decade, TTB believes that it can gain... minimum manufacturing and marking requirements for tobacco products and cigarette papers and tubes, and...

Harvesting full-duplex rate gains in cellular networks with half-duplex user terminals

KAUST Repository

AlAmmouri, Ahmad

2016-07-26

Full-Duplex (FD) transceivers may be expensive in terms of complexity, power consumption, and price to be implemented in all user terminals. Therefore, techniques to exploit in-band full-duplex communication with FD base stations (BSs) and half-duplex (HD) users\\' equipment (UEs) are required. In this context, 3-node topology (3NT) has been recently proposed for FD BSs to reuse the uplink (UL) and downlink (DL) channels with HD terminals within the same cell. In this paper, we present a tractable mathematical framework, based on stochastic geometry, for 3NT in cellular networks. To this end, we propose a design paradigm via pulse-shaping and partial overlap between UL and DL channels to maximize the harvested rate gains in 3NT. The results show that 3NT achieves a close performance to networks with FD BSs and FD UEs, denoted by 2-node topology (2NT) networks. A maximum of 5% rate loss is reported when 3NT is compared to 2NT with efficient self-interference cancellation (SIC). If the SIC in 2NT is not efficient, 3NT highly outperforms 2NT. Consequently, we conclude that, irrespective to the UE duplexing scheme, it is sufficient to have FD BSs to harvest FD rate gains.

Age differences in gain- and loss-motivated attention.

Science.gov (United States)

Williams, Ryan S; Biel, Anna Lena; Dyson, Benjamin J; Spaniol, Julia

2017-02-01

Adaptive gain theory (Aston-Jones & Cohen, 2005) suggests that the phasic release of norepinephrine (NE) to cortical areas reflects changes in the utility of ongoing tasks. In the context of aging, this theory raises interesting questions, given that the motivations of older adults differ from those of younger adults. According to socioemotional selectivity theory (Carstensen, Isaacowitz, & Charles, 1999), aging is associated with greater emphasis on emotion-regulation goals, leading older adults to prioritize positive over negative information. This suggests that the phasic release of NE in response to threatening stimuli may be diminished in older adults. In the present study, younger adults (aged 18-34years) and older adults (60-82years) completed the Attention Network Test (ANT), modified to include an incentive manipulation. A behavioral index of attentional alerting served as a marker of phasic arousal. For younger adults, this marker correlated with the effect of both gain and loss incentives on performance. For older adults, in contrast, the correlation between phasic arousal and incentive sensitivity held for gain incentives only. These findings suggest that the enlistment of phasic NE activity may be specific to approach-oriented motivation in older adults. Copyright © 2016. Published by Elsevier Inc.

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.

Dosimeter characteristics and service performance requirements

International Nuclear Information System (INIS)

Ambrosi, P.; Bartlett, D.T.

1999-01-01

The requirements for personal dosimeters and dosimetry services given by ICRP 26, ICRP 35, ICRP 60 and ICRP 75 are summarised and compared with the requirements given in relevant international standards. Most standards could be made more relevant to actual workplace conditions. In some standards, the required tests of energy and angular dependence of the response are not sufficient, or requirements on overall uncertainty are lacking. (author)

Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

Science.gov (United States)

Čeko, Marta; Gracely, John L; Fitzcharles, Mary-Ann; Seminowicz, David A; Schweinhardt, Petra; Bushnell, M Catherine

2015-08-19

In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or "negative" [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether a responsive DMN is required for successful cognitive performance, we compared healthy human subjects (n = 23) with individuals shown to have decreased DMN engagement (chronic pain patients, n = 28). Subjects performed a multilevel working-memory task (N-back) during fMRI. If a responsive DMN is required for successful performance, patients having reduced DMN responsiveness should show worsened performance; if performance is not reduced, their brains should show compensatory activation in external-task-positive regions or elsewhere. All subjects showed decreased accuracy and increased reaction times with increasing task level, with no significant group differences on either measure at any level. Patients had significantly reduced negative fMRI response (deactivation) of DMN regions (posterior cingulate/precuneus, medial prefrontal cortex). Controls showed expected modulation of DMN deactivation with increasing task difficulty. Patients showed significantly reduced modulation of DMN deactivation by task difficulty, despite their successful task performance. We found no evidence of compensatory neural recruitment in external-task-positive regions or elsewhere. Individual responsiveness of the external-task-positive ventrolateral prefrontal cortex, but not of DMN regions, correlated with task accuracy. These findings suggest that a responsive DMN may not be required for successful cognitive performance; a responsive external-task-positive network may be sufficient. We studied the

Gains in Life Expectancy Associated with Higher Education in Men.

Science.gov (United States)

Bijwaard, Govert E; van Poppel, Frans; Ekamper, Peter; Lumey, L H

2015-01-01

Many studies show large differences in life expectancy across the range of education, intelligence, and socio-economic status. As educational attainment, intelligence, and socio-economic status are highly interrelated, appropriate methods are required to disentangle their separate effects. The aim of this paper is to present a novel method to estimate gains in life expectancy specifically associated with increased education. Our analysis is based on a structural model in which education level, IQ at age 18 and mortality all depend on (latent) intelligence. The model allows for (selective) educational choices based on observed factors and on an unobserved factor capturing intelligence. Our estimates are based on information from health examinations of military conscripts born in 1944-1947 in The Netherlands and their vital status through age 66 (n = 39,798). Our empirical results show that men with higher education have lower mortality. Using structural models to account for education choice, the estimated gain in life expectancy for men moving up one educational level ranges from 0.3 to 2 years. The estimated gain in months alive over the observational period ranges from -1.2 to 5.7 months. The selection effect is positive and amounts to a gain of one to two months. Decomposition of the selection effect shows that the gain from selection on (latent) intelligence is larger than the gain from selection on observed factors and amounts to 1.0 to 1.7 additional months alive. Our findings confirm the strong selection into education based on socio-economic status and intelligence. They also show significant higher life expectancy among individuals with higher education after the selectivity of education choice has been taken into account. Based on these estimates, it is plausible therefore that increases in education could lead to increases in life expectancy.

Generating units performances: power system requirements

Energy Technology Data Exchange (ETDEWEB)

Fourment, C; Girard, N; Lefebvre, H

1994-08-01

The part of generating units within the power system is more than providing power and energy. Their performance are not only measured by their energy efficiency and availability. Namely, there is a strong interaction between the generating units and the power system. The units are essential components of the system: for a given load profile the frequency variation follows directly from the behaviour of the units and their ability to adapt their power output. In the same way, the voltage at the units terminals are the key points to which the voltage profile at each node of the network is linked through the active and especially the reactive power flows. Therefore, the customer will experience the frequency and voltage variations induced by the units behaviour. Moreover, in case of adverse conditions, if the units do not operate as well as expected or trip, a portion of the system, may be the whole system, may collapse. The limitation of the performance of a unit has two kinds of consequences. Firstly, it may result in an increased amount of not supplied energy or loss of load probability: for example if the primary reserve is not sufficient, a generator tripping may lead to an abnormal frequency deviation, and load may have to be shed to restore the balance. Secondly, the limitation of a unit performance results in an economic over-cost for the system: for instance, if not enough `cheap` units are able to load-following, other units with higher operating costs have to be started up. We would like to stress the interest for the operators and design teams of the units on the one hand, and the operators and design teams of the system on the other hand, of dialog and information exchange, in operation but also at the conception stage, in order to find a satisfactory compromise between the system requirements and the consequences for the generating units. (authors). 11 refs., 4 figs.

Dynamic excitatory and inhibitory gain modulation can produce flexible, robust and optimal decision-making.

Directory of Open Access Journals (Sweden)

Ritwik K Niyogi

Full Text Available Behavioural and neurophysiological studies in primates have increasingly shown the involvement of urgency signals during the temporal integration of sensory evidence in perceptual decision-making. Neuronal correlates of such signals have been found in the parietal cortex, and in separate studies, demonstrated attention-induced gain modulation of both excitatory and inhibitory neurons. Although previous computational models of decision-making have incorporated gain modulation, their abstract forms do not permit an understanding of the contribution of inhibitory gain modulation. Thus, the effects of co-modulating both excitatory and inhibitory neuronal gains on decision-making dynamics and behavioural performance remain unclear. In this work, we incorporate time-dependent co-modulation of the gains of both excitatory and inhibitory neurons into our previous biologically based decision circuit model. We base our computational study in the context of two classic motion-discrimination tasks performed in animals. Our model shows that by simultaneously increasing the gains of both excitatory and inhibitory neurons, a variety of the observed dynamic neuronal firing activities can be replicated. In particular, the model can exhibit winner-take-all decision-making behaviour with higher firing rates and within a significantly more robust model parameter range. It also exhibits short-tailed reaction time distributions even when operating near a dynamical bifurcation point. The model further shows that neuronal gain modulation can compensate for weaker recurrent excitation in a decision neural circuit, and support decision formation and storage. Higher neuronal gain is also suggested in the more cognitively demanding reaction time than in the fixed delay version of the task. Using the exact temporal delays from the animal experiments, fast recruitment of gain co-modulation is shown to maximize reward rate, with a timescale that is surprisingly near the

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.

Genetic and phenotypic relationships of serum leptin concentration with performance, efficiency of gain, and carcass merit of feedlot cattle.

Science.gov (United States)

Nkrumah, J D; Keisler, D H; Crews, D H; Basarab, J A; Wang, Z; Li, C; Price, M A; Okine, E K; Moore, S S

2007-09-01

Leptin is the hormone product of the obese gene that is synthesized and predominantly expressed by adipocytes. This study estimated the genetic variation in serum leptin concentration and evaluated the genetic and phenotypic relationships of serum leptin concentration with performance, efficiency of gain, and carcass merit. There were 464 steers with records for serum leptin concentration, performance, and efficiency of gain and 381 steers with records for carcass traits. The analyses included a total of 813 steers, including those without phenotypic records. Phenotypic and genetic parameter estimates were obtained using SAS and ASREML, respectively. Serum leptin concentration was moderately heritable (h2 = 0.34 +/- 0.13) and averaged 13.91 (SD = 5.74) ng/mL. Sire breed differences in serum leptin concentration correlated well with breed differences in body composition. Specifically, the serum leptin concentration was 20% greater in Angus-sired steers compared with Charolais-sired steers (P 0.10). Serum leptin concentration was correlated phenotypically with ultrasound backfat (r = 0.41; P < 0.001), carcass 12th-rib fat (r = 0.42; P < 0.001), ultrasound marbling (r = 0.25; P < 0.01), carcass marbling (r = 0.28; P < 0.01), ultrasound LM area (r = -0.19; P < 0.01), carcass LM area (r = -0.17; P < 0.05), lean meat yield (r = -0.38; P < 0.001), and yield grade (r = 0.32; P < 0.001). The corresponding genetic correlations were generally greater than the phenotypic correlations and included ultrasound backfat (r = 0.76 +/- 0.19), carcass 12th-rib fat (r = 0.54 +/- 0.23), ultrasound marbling (r = 0.27 +/- 0.22), carcass marbling (r = 0.76 +/- 0.21), ultrasound LM area (r = -0.71 +/- 0.19), carcass LM area (r = -0.75 +/- 0.20), lean meat yield (r = -0.59 +/- 0.22), and yield grade (r = 0.39 +/- 0.26). Serum leptin concentration can be a valuable tool that can be incorporated into appropriate selection programs to favorably improve the carcass merit of cattle.

Microscopic analysis of the optoelectronic properties of semiconductor gain media for laser applications; Mikroskopische Analyse optoelektronischer Eigenschaften von Halbleiterverstaerkungsmedien fuer Laseranwendungen

Energy Technology Data Exchange (ETDEWEB)

Bueckers, Christina

2010-12-03

A microscopic many-particle theory is applied to model a wide range of semiconductor laser gain materials. The fundamental understanding of the gain medium and the underlying carrier interaction processes allow for the quantitative prediction of the optoelectronic properties governing the laser performance. Detailed theory-experiment-comparisons are shown for a variety of structures demonstrating the application capabilities of the theoretical approach. The microscopically calculated material properties, in particular absorption, optical gain, luminescence and the intrinsic carrier losses due to radiative and Auger-recombination, constitute the critical input to analyse and design laser structures. On this basis, important system features such as laser wavelength or threshold behaviour become predictable. However, the theory is also used in a diagnostic fashion, e.g. to extract otherwise poorly known structural parameter. Thus, novel concepts for the optimisation of laser designs may be developed with regard to the requirements of specific applications. Moreover, the approach allows for the systematic exploration and assessment of completely novel material systems and their application potential. (orig.)

Learning Gains from a Recurring "Teach and Question" Homework Assignment in a General Biology Course: Using Reciprocal Peer Tutoring Outside Class.

Science.gov (United States)

Bailey, E G; Baek, D; Meiling, J; Morris, C; Nelson, N; Rice, N S; Rose, S; Stockdale, P

2018-06-01

Providing students with one-on-one interaction with instructors is a big challenge in large courses. One solution is to have students interact with their peers during class. Reciprocal peer tutoring (RPT) is a more involved interaction that requires peers to alternate the roles of "teacher" and "student." Theoretically, advantages for peer tutoring include the verbalization and questioning of information and the scaffolded exploration of material through social and cognitive interaction. Studies on RPT vary in their execution, but most require elaborate planning and take up valuable class time. We tested the effectiveness of a "teach and question" (TQ) assignment that required student pairs to engage in RPT regularly outside class. A quasi-experimental design was implemented: one section of a general biology course completed TQ assignments, while another section completed a substitute assignment requiring individuals to review course material. The TQ section outperformed the other section by ∼6% on exams. Session recordings were coded to investigate correlation between TQ quality and student performance. Asking more questions was the characteristic that best predicted exam performance, and this was more predictive than most aspects of the course. We propose the TQ as an easy assignment to implement with large performance gains.

Does Adoption of Management Standards Deliver Efficiency Gain in Firms’ Pursuit of Sustainability Performance? An Empirical Investigation of Chinese Manufacturing Firms

Directory of Open Access Journals (Sweden)

Xiaoling Wang

2016-07-01

Full Text Available Building on longitudinal data from 73 Chinese manufacturing firms during 2009–2012, we assess whether and how firms gain higher efficiency in achieving their sustainability goals by adopting management practice standards (ISO 9001, ISO 14001, and/or OHSAS 18001. We propose four pathways for firms to gain sustainability efficiency in their certification journey: participation, qualitative integration, quantitative expansion, and temporal accumulation. Our results confirm that firms certifying management standards gain higher efficiency in pursuing their sustainability goals than firms without these standards. We also find some support for increased efficiency effect in firms with diverse management systems over firms with only a single certificate in 2011. Finally, our results highlight the experiential and temporal accumulation effect of such efficiency gains, that is, firms with prior certification experience or having a longer certification history demonstrate higher efficiency gains in pursuing their sustainability goals.

MYRRHA cryogenic system study on performances and reliability requirements

International Nuclear Information System (INIS)

Junquera, T.; Chevalier, N.R.; Thermeau, J.P.; Medeiros Romao, L.; Vandeplassche, D.

2015-01-01

A precise evaluation of the cryogenic requirements for accelerator-driven system such as the MYRRHA project has been performed. In particular, operation temperature, thermal losses, and required cryogenic power have been evaluated. A preliminary architecture of the cryogenic system including all its major components, as well as the principles for the cryogenic fluids distribution has been proposed. A detailed study on the reliability aspects has also been initiated. This study is based on the reliability of large cryogenic systems used for accelerators like HERA, LHC or SNS Linac. The requirements to guarantee good cryogenic system availability can be summarised as follows: 1) Mean Time Between Maintenance (MTBM) should be > 8 000 hours; 2) Valves, heat exchangers and turbines are particularly sensitive elements to impurities (dust, oil, gases), improvements are necessary to keep a minimal level in these components; 3) Redundancy studies for all elements containing moving/vibrating parts (turbines, compressors, including their respective bearings and seal shafts) are necessary; 4) Periodic maintenance is mandatory: oil checks, control of screw compressors every 10.000-15.000 hours, vibration surveillance programme, etc; 5) Special control and maintenance of utilities equipment (supply of cooling water, compressed air and electrical supply) is necessary; 6) Periodic vacuum checks to identify leakage appearance such as insulation vacuum of transfer lines and distribution boxes are necessary; 7) Easily exchangeable cold compressors are required

Gaining Access to Hidden Populations: Strategies for Gaining Cooperation of Drug Sellers/Dealers and Their Families in Ethnographic Research

Science.gov (United States)

Dunlap, Eloise; Johnson, Bruce D.

2009-01-01

Summary This article examines strategies for gaining the cooperation of drug sellers and their families in order to conduct ethnographic research. The strategies were developed during an eight year study of drug dealers in New York City. A key element in gaining the ability to talk with and observe drug dealers and their family members was the availability of funds to compensate respondents for interviews and other expenses associated with building and maintaining rapport. Access to more successful crack sellers and dealers rested upon the right contacts. The “right contact” is a critical element. Locating a trusted “go-between” was adapted from strategies employed by cocaine sellers to arrange transactions involving large quantities of drugs. Such transactions rely upon a trusted associate of a dealer, the “go-between,” who performs various roles and assumes risks the dealer wishes to avoid. The role of the go-between became important when ethnographers attempted to reach drug dealers for research purposes. Favors and trust are central components in the equation of access to the dealer and his family. Favors are a part of drug dealers' interaction patterns: everyone owes someone else a favor. Such reciprocity norms exist independently of the amount of drugs involved and outlast any particular transaction. Reputations and favors are related. This framework of favors, trust, and reciprocity provides a basis for the ethnographer to gain an introduction to dealers and sellers. The “go-between” is critical because he/she explains the ethnographer's role to the dealer and helps arrange an initial meeting between the ethnographer and the seller. Once the go-between has provided an initial introduction, the ethnographer marshals the communication skills necessary to convince the dealer to allow further contact and conversations. This article examines the ritual of initial conversation within its cultural framework. Developing rapport requires showing

Antenna Gain Impact on UWB Wind Turbine Blade Deflection Sensing

DEFF Research Database (Denmark)

Zhang, Shuai; Franek, Ondrej; Byskov, Claus

2018-01-01

effective (or equivalent) isotropic radiated power (EIRP), an HG tip antenna inside a blade gives stronger direct pulse amplitudes and better pulse waveforms for accurate and reliable distance estimations than the LG. Moreover, the direct pulse with the HG antenna is also closer to the blade surface, which...... in free space have similar realized gain when allocated inside blades, so that the emission power for the HG and LG antennas in blades can be the same. The antenna gain impacts on time-domain pulse waveforms and power distributions around a blade are carefully investigated (with the tip antenna inside...... a blade). Higher antenna gain enlarges both direct pulse and multipath but in different levels. To verify the simulations, time-domain measurements are performed with a full 37-meter blade. Pulse waveforms and power delay profiles are measured. From all the studies, it follows that: with the similar...

Emotional eating as a mediator between depression and weight gain.

Science.gov (United States)

van Strien, Tatjana; Konttinen, Hanna; Homberg, Judith R; Engels, Rutger C M E; Winkens, Laura H H

2016-05-01

Depression is often associated with weight gain but underlying mechanisms are unclear. This study assessed whether three psychological eating styles (emotional eating, external eating and restrained eating) act as mediators between depression and weight gain. We used structural equation modelling to test the hypothesized mediation models in a sample of 298 fathers and 294 mothers by assessing self-reported eating styles (Dutch Eating Behavior Questionnaire), depressive feelings (Depressive Mood List) and body mass index (BMI) at baseline and BMI after five years. In the model with emotional eating we also assessed the moderation effect of 5-HTTLPR genotype in a sub-sample of 520 Caucasians. All analyses were performed separately for the two sexes. Although the overall effect of depression on weight gain was statistically non-significant in both sexes, there was a causal chain between depression, emotional eating and weight gain in the mothers. Depressive symptoms were related to higher emotional eating and emotional eating predicted greater increases in BMI independently of depression. Moreover, the indirect effect (via emotional eating) of depression on BMI change was significant (Beta = 0.18, P = 0.026). This mediation effect was found to be independent of 5-HTTLPR genotype. No such mediation effect was found for the fathers. Further, external eating and restrained eating did not act as mediators between depression and weight gain in either sex. The finding that emotional eating acted as mediator between depression and weight gain in the mothers suggests that obesity interventions should take emotional eating into account. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling the Non-functional Requirements in the Context of Usability, Performance, Safety and Security

OpenAIRE

Sadiq, Mazhar

2007-01-01

Requirement engineering is the most significant part of the software development life cycle. Until now great emphasis has been put on the maturity of the functional requirements. But with the passage of time it reveals that the success of software development does not only pertain to the functional requirements rather non-functional requirements should also be taken into consideration. Among the non-functional requirements usability, performance, safety and security are considered important. ...

Energy Gaining Windows for Residental Buildings

DEFF Research Database (Denmark)

Kragh, Jesper; Laustsen, Jacob Birck; Svendsen, Svend

2008-01-01

This paper presents some of the research done during the last 8 years at the Technical University of Denmark developing improved low-energy window solutions. The focus has been on maximizing the net energy gain of windows for residential buildings. The net energy gain of windows is the solar gain...... minus the heat loss integrated over the heating season. It is assumed that in northern cold climates all of the solar gain during the heating season can be utilized for space heating. Problems with overheating in the summer period must be solved with overhang or moveable solar shading devices. Two...... and longer durability of the window. The glazing in these fiber reinforced polyester windows is both unsealed and sealed triple glazing units. To increase the net energy gain slim frame profiles have been developed to increase the glazing area and thereby the solar gain. The challenge when developing slim...

Polyurethane foam pica in a patient with excessive interdialytic weight gain

Science.gov (United States)

Iyasere, Osasuyi; Allington, Ying; Cafferkey, Michele

2010-01-01

Maintaining fluid balance in haemodialysis patients is important because of the adverse effects of excessive interdialytic weight gain. This often requires fluid restriction that patients often struggle with. We report a case of a 31-year-old female diabetic patient on haemodialysis with repeated excessive interdialytic weight gains despite fluid restriction and dry weight adjustment. It was subsequently discovered that she devised an unusual, albeit unsuccessful, strategy of eating the polyurethane foam from her dialysis chair while increasing her fluid intake hoping that it would absorb excess water in the gut! This under-diagnosed phenomenon known as pica has been reported in renal patients with substances such as ice, clay and baking soda. PMID:22767521

A Study on Performance Requirements for Advanced Alarm System

International Nuclear Information System (INIS)

Seong, Duk Hyun; Jeong, Jae Hoon; Sim, Young Rok; Ko, Jong Hyun; Kim, Jung Seon; Jang, Gwi Sook; Park, Geun Ok

2005-01-01

A design goals of advanced alarm system is providing advanced alarm information to operator in main control room. To achive this, we applied computer based system to Alarm System. Because, It should apply data management and advanced alarm processing(ie. Data Base Mangegment System and S/W module for alarm processing). These are not impossible in analog based alarm system. And, preexitance research examples are made on digital computer. We have digital systems for test of advanced alarm system table and have tested and studied using by test equipment in the view point of the system performance, stability and security. In this paper, we discribed about general software architecture of preexitance research examples. Also, CPU performance and requirements of system software that served to accommodate it, stability and security

Optimal weight gain in triplet pregnancies.

Science.gov (United States)

Johnston, Robert C; Erfani, Hadi; Shamshirsaz, Amir A; Spiel, Melissa; Ravangard, Sam F; Shaman, Majid; Allaf, M Baraa; Shamshirsaz, Alireza A; Haeri, Sina

2017-08-01

To identify appropriate weight gain in triplet gestations, which may aid in reducing the risk of perinatal morbidity within this high-risk cohort. This retrospective cohort study evaluated all non-anomalous triplet pregnancies between 23 and 40 weeks' gestation resulting in live births at five tertiary-care medical centers between 1991 and 2011. Subjects were divided by pre-pregnancy BMI into underweight, normal-weight, overweight, and obese groups, and then stratified by low (gain (≥1.5 lbs/week). Primary outcomes included spontaneous preterm birth and preeclampsia. We included 116 mothers and 348 corresponding neonates for final analysis. The incidence of preeclampsia and preterm delivery less than 32 weeks' gestation was 37% and 41%, respectively. The incidence of preeclampsia increased with weight gain per week, but was not statistically different from subjects who gained less weight. We found no statistical correlation between weight gain per week and preterm delivery. We found no association between preeclampsia or preterm delivery and increasing weight gain in triplet pregnancies. The association with increased risk for preeclampsia was predominantly due to BMI effect. Based on the current study, recommendations for optimal weight gain in mothers with triplet gestations could not be defined.

Mode control in a high-gain relativistic klystron amplifier

Science.gov (United States)

Li, Zheng-Hong; Zhang, Hong; Ju, Bing-Quan; Su, Chang; Wu, Yang

2010-05-01

Middle cavities between the input and output cavity can be used to decrease the required input RF power for the relativistic klystron amplifier. Meanwhile higher modes, which affect the working mode, are also easy to excite in a device with more middle cavities. In order for the positive feedback process for higher modes to be excited, a special measure is taken to increase the threshold current for such modes. Higher modes' excitation will be avoided when the threshold current is significantly larger than the beam current. So a high-gain S-band relativistic klystron amplifier is designed for the beam of current 5 kA and beam voltage 600 kV. Particle in cell simulations show that the gain is 1.6 × 105 with the input RF power of 6.8 kW, and that the output RF power reaches 1.1 GW.

Fractal Based Triple Band High Gain Monopole Antenna

Science.gov (United States)

Pandey, Shashi Kant; Pandey, Ganga Prasad; Sarun, P. M.

2017-10-01

A novel triple-band microstrip fed planar monopole antenna is proposed and investigated. A fractal antenna is created by iterating a narrow pulse (NP) generator model at upper side of modified ground plane, which has a rhombic patch, for enhancing the bandwidth and gain. Three iterations are carried out to study the effects of fractal geometry on the antenna performance. The proposed antenna can operate over three frequency ranges viz, 3.34-4.8 GHz, 5.5-10.6 GHz and 13-14.96 GHz suitable for WLAN 5.2/5.8 GHz, WiMAX 3.5/5.5 GHz and X band applications respectively. Simulated and measured results are in good agreements with each others. Results show that antenna provides wide/ultra wide bandwidths, monopole like radiation patterns and very high antenna gains over the operating frequency bands.

CREATINE SUPPLEMENTATION AND EXERCISE PERFORMANCE: A BRIEF REVIEW

Directory of Open Access Journals (Sweden)

Stephen P. Bird

2003-12-01

Full Text Available During the past decade, the nutritional supplement creatine monohydrate has been gaining popularity exponentially. Introduced to the general public in the early 1990s, shortly after the Barcelona Olympic Games, creatine (Cr has become one of the most widely used nutritional supplements or ergogenic aids, with loading doses as high as 20-30 g·day-1 for 5-7 days typical among athletes. This paper reviews the available research that has examined the potential ergogenic value of creatine supplementation (CrS on exercise performance and training adaptations. Short-term CrS has been reported to improve maximal power/strength, work performed during sets of maximal effort muscle contractions, single-effort sprint performance, and work performed during repetitive sprint performance. During training CrS has been reported to promote significantly greater gains in strength, fat free mass, and exercise performance primarily of high intensity tasks. However, not all studies demonstrate a beneficial effect on exercise performance, as CrS does not appear to be effective in improving running and swimming performance. CrS appears to pose no serious health risks when taken at doses described in the literature and may enhance exercise performance in individuals that require maximal single effort and/or repetitive sprint bouts

Neonates with Bartter syndrome have enormous fluid and sodium requirements.

Science.gov (United States)

Azzi, Antonio; Chehade, Hassib; Deschênes, Georges

2015-07-01

Managing neonatal Bartter syndrome by achieving adequate weight gain is challenging. We assessed the correlation between weight gain in neonatal Bartter syndrome and the introduction of fluid and sodium supplementations and indomethacin during the first 4 weeks of life. Daily fluid and electrolytes requirements were analysed using linear regression and Spearman correlation coefficients. The weight gain coefficient was calculated as daily weight gain after physiological neonatal weight loss. We studied seven infants. The highest weight gain coefficients occurred between weeks two and four in the five neonates who either received prompt amounts of fluid (maximum 810 mL/kg/day) and sodium (maximum 70 mmol/kg/day) or were treated with indomethacin. For the two patients with the highest weight gain coefficient, water and sodium supplementations were decreased in weeks two to four leading to a significant negative Spearman correlation between weight gain and fluid supplements (r = -0.55 and -0.68) and weight gain and sodium supplementations (r = -0.96 and -0.72). The two patients with the lowest weight gain coefficient had positive Spearman correlation coefficients between weight gain and fluid and sodium supplementations. Infants with neonatal Bartter syndrome required rapid and enormous fluid and sodium supplementations or the early introduction of indomethacin treatment to achieve adequate weight gain during the early postnatal period. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

A SiGe High Gain and Highly Linear F-Band Single-Balanced Subharmonic Mixer

OpenAIRE

Seyedhosseinzadeh, Neda; Nabavi, Abdolreza; Carpenter, Sona; He, Zhongxia Simon; Bao, Mingquan; Zirath, Herbert

2017-01-01

A compact, broadband, high gain, second-order active down-converter subharmonic mixer is demonstrated using a 130-nm SiGe BiCMOS technology. The mixer adopts a bottom-LO Gilbert topology, on-chip RF and LO baluns and two emitter-follower buffers to realize a high gain wideband operation in both RF and IF frequencies. The measured performance exhibits a flat conversion gain (CG) of about 11 dB from 90 to 130 GHz with an average LO power of +3 dBm and high 2LO-RF isolation better than 60 dB. Th...

A high gain wide dynamic range transimpedance amplifier for optical receivers

International Nuclear Information System (INIS)

Liu Lianxi; Zou Jiao; Liu Shubin; Niu Yue; Zhu Zhangming; Yang Yintang; En Yunfei

2014-01-01

As the front-end preamplifiers in optical receivers, transimpedance amplifiers (TIAs) are commonly required to have a high gain and low input noise to amplify the weak and susceptible input signal. At the same time, the TIAs should possess a wide dynamic range (DR) to prevent the circuit from becoming saturated by high input currents. Based on the above, this paper presents a CMOS transimpedance amplifier with high gain and a wide DR for 2.5 Gbit/s communications. The TIA proposed consists of a three-stage cascade pull push inverter, an automatic gain control circuit, and a shunt transistor controlled by the resistive divider. The inductive-series peaking technique is used to further extend the bandwidth. The TIA proposed displays a maximum transimpedance gain of 88.3 dBΩ with the −3 dB bandwidth of 1.8 GHz, exhibits an input current dynamic range from 100 nA to 10 mA. The output voltage noise is less than 48.23 nV/√Hz within the −3 dB bandwidth. The circuit is fabricated using an SMIC 0.18 μm 1P6M RFCMOS process and dissipates a dc power of 9.4 mW with 1.8 V supply voltage. (semiconductor integrated circuits)

Predicting sample size required for classification performance

Directory of Open Access Journals (Sweden)

Figueroa Rosa L

2012-02-01

Full Text Available Abstract Background Supervised learning methods need annotated data in order to generate efficient models. Annotated data, however, is a relatively scarce resource and can be expensive to obtain. For both passive and active learning methods, there is a need to estimate the size of the annotated sample required to reach a performance target. Methods We designed and implemented a method that fits an inverse power law model to points of a given learning curve created using a small annotated training set. Fitting is carried out using nonlinear weighted least squares optimization. The fitted model is then used to predict the classifier's performance and confidence interval for larger sample sizes. For evaluation, the nonlinear weighted curve fitting method was applied to a set of learning curves generated using clinical text and waveform classification tasks with active and passive sampling methods, and predictions were validated using standard goodness of fit measures. As control we used an un-weighted fitting method. Results A total of 568 models were fitted and the model predictions were compared with the observed performances. Depending on the data set and sampling method, it took between 80 to 560 annotated samples to achieve mean average and root mean squared error below 0.01. Results also show that our weighted fitting method outperformed the baseline un-weighted method (p Conclusions This paper describes a simple and effective sample size prediction algorithm that conducts weighted fitting of learning curves. The algorithm outperformed an un-weighted algorithm described in previous literature. It can help researchers determine annotation sample size for supervised machine learning.

Weight suppression predicts total weight gain and rate of weight gain in outpatients with anorexia nervosa.

Science.gov (United States)

Carter, Frances A; Boden, Joseph M; Jordan, Jennifer; McIntosh, Virginia V W; Bulik, Cynthia M; Joyce, Peter R

2015-11-01

The present study sought to replicate the finding of Wildes and Marcus, Behav Res Ther, 50, 266-274, 2012 that higher levels of weight suppression at pretreatment predict greater total weight gain, faster rate of weight gain, and bulimic symptoms amongst patients admitted with anorexia nervosa. Participants were 56 women with anorexia nervosa diagnosed by using strict or lenient weight criteria, who were participating in a randomized controlled psychotherapy trial (McIntosh et al., Am J Psychiatry, 162, 741-747, 2005). Thirty-five women completed outpatient treatment and post-treatment assessment. Weight suppression was the discrepancy between highest lifetime weight at adult height and weight at pretreatment assessment. Outcome variables were total weight gain, rate of weight gain, and bulimic symptoms in the month prior to post-treatment assessment [assessed using the Eating Disorders Examination (Fairburn et al., Binge-Eating: Nature, Assessment and Treatment. New York: Guilford, 1993)]. Weight suppression was positively associated with total weight gain and rate of weight gain over treatment. Regression models showed that this association could not be explained by covariates (age at onset of anorexia nervosa and treatment modality). Weight suppression was not significantly associated with bulimic symptoms in the month prior to post-treatment assessment, regardless of whether bulimic symptoms were examined as continuous or dichotomous variables. The present study reinforces the previous finding that weight suppression predicts total weight gain and rate of weight gain amongst patients being treated for anorexia nervosa. Methodological issues may explain the failure of the present study to find that weight suppression predicts bulimic symptoms. Weight suppression at pretreatment for anorexia nervosa should be assessed routinely and may inform treatment planning. © 2015 Wiley Periodicals, Inc.

Perspectives used for gaining approval of budgets.

Science.gov (United States)

Franks-Joiner, G L

1990-01-01

Nurse executives think about problems using a certain perspective which may influence decisions on budgetary matters. The nurse executives' perspective used in decision-making may influence which budget proposals are developed and approved. A study was performed to determine the perspective used by nurse executives in decision-making on supplementary budget item proposals and whether perspective use influenced approval. Findings showed that use of the system view or dual-domain perspective in a proposal may enhance nurse executives' changes of gaining approval.

MOSFET-Only Mixer/IIR Filter with Gain using Parametric Amplification

DEFF Research Database (Denmark)

Custódio, José R.; Oliveira, J.; Oliveira, L. B.

2010-01-01

This paper describes the design of a discrete-time passive Mixer/IIR filter. The use of an improved MOS Parametric Amplification leads to a moderate gain in the signal path and improved noise performance, instead of the conversion loss inherent to passive mixers. Simulation results demonstrate th...

Gain measurements in CO2 CW low pressure lasers

International Nuclear Information System (INIS)

Rodrigues, N.A.S.; Chanes Junior, J.B.; Jayaram, K.

1983-01-01

A series of gain measurements in low pressure CO 2 CW laser were performed in order to study the behaviour of a CO 2 laser ampliflier as a function of pressure and discharge current. A theoretical model, based on rate equations is also presented to describe the laser behaviour and the experimental procedure adopted. (C.L.B.) [pt

Generalized gain scheduling for deloaded wind turbine operation

DEFF Research Database (Denmark)

Venne, Philippe; Guillaud, X.; Teodorescu, Remus

2010-01-01

to regulate both power production and rotor speed under any wind speed conditions. In this paper, a novel controller for deloaded wind turbine operation is presented. This controller is made possible by a Cp table inversion procedure allowing generalized gain scheduling for linearization of the pitch response......The ability to produce less power than what is available from a wind source, a condition known as deloaded operation, is needed for a wind turbine to reproduce synchronous machine behavior in terms of inertial response and frequency droop regulation. Deloaded operation requires the ability...

Measurement of Antenna Bore-Sight Gain

Science.gov (United States)

Fortinberry, Jarrod; Shumpert, Thomas H.

2016-01-01

The absolute or free-field gain of a simple antenna can be approximated using standard antenna theory formulae or for a more accurate prediction, numerical methods may be employed to solve for antenna parameters including gain. Both of these methods will result in relatively reasonable estimates but in practice antenna gain is usually verified and documented via measurements and calibration. In this paper, a relatively simple and low-cost, yet effective means of determining the bore-sight free-field gain of a VHF/UHF antenna is proposed by using the Brewster angle relationship.

Redesign of a Variable-Gain Output Feedback Longitudinal Controller Flown on the High-Alpha Research Vehicle (HARV)

Science.gov (United States)

Ostroff, Aaron J.

1998-01-01

This paper describes a redesigned longitudinal controller that flew on the High-Alpha Research Vehicle (HARV) during calendar years (CY) 1995 and 1996. Linear models are developed for both the modified controller and a baseline controller that was flown in CY 1994. The modified controller was developed with three gain sets for flight evaluation, and several linear analysis results are shown comparing the gain sets. A Neal-Smith flying qualities analysis shows that performance for the low- and medium-gain sets is near the level 1 boundary, depending upon the bandwidth assumed, whereas the high-gain set indicates a sensitivity problem. A newly developed high-alpha Bode envelope criterion indicates that the control system gains may be slightly high, even for the low-gain set. A large motion-base simulator in the United Kingdom was used to evaluate the various controllers. Desired performance, which appeared to be satisfactory for flight, was generally met with both the low- and medium-gain sets. Both the high-gain set and the baseline controller were very sensitive, and it was easy to generate pilot-induced oscillation (PIO) in some of the target-tracking maneuvers. Flight target-tracking results varied from level 1 to level 3 and from no sensitivity to PIO. These results were related to pilot technique and whether actuator rate saturation was encountered.

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.

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....

Accounting for Marketing: Marketing Performance Through Financial Results

OpenAIRE

Levent KOSAN

2014-01-01

Accounting, especially strategic management accounting, provides significant contributions to companies for decisions in environments of intense competition. Accounting, which has positive effects of company strategy development and management, has become a required facet of marketing, another area that has gained significance. The aim of this study is to assess the contributions of accounting to marketing performance management and other areas related to marketing development and to evaluate...

An application of gain-scheduled control using state-space interpolation to hydroactive gas bearings

DEFF Research Database (Denmark)

Theisen, Lukas Roy Svane; Camino, Juan F.; Niemann, Hans Henrik

2016-01-01

with a gain-scheduling strategy using state-space interpolation, which avoids both the performance loss and the increase of controller order associated to the Youla parametrisation. The proposed state-space interpolation for gain-scheduling is applied for mass imbalance rejection for a controllable gas...... bearing scheduled in two parameters. Comparisons against the Youla-based scheduling demonstrate the superiority of the state-space interpolation....

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...

Gestational Weight Gain and Pregnancy Outcomes in 481 Obese Glucose-Tolerant Women

DEFF Research Database (Denmark)

Jensen, Dorte Møller; Ovesen, Per; Beck-Nielsen, Henning

2005-01-01

OBJECTIVE: To investigate the effect of gestational weight gain in obese glucose-tolerant women. RESEARCH DESIGN AND METHODS: We performed a historical cohort study of 481 women with prepregnancy BMI > or = 30 kg/m2 and a normal 2-h 75-g oral glucose tolerance test (OGTT) during the third trimester......-weight women (3,478 g). In multivariate analyses, increasing weight gain was associated with significantly higher rates of hypertension (OR 4.8 [95% CI for group 4 vs. group 1: 1.7-13.1]), cesarean section (3.5 [1.6-7.8]), induction of labor (3.7 [1.7-8.0]), and large-for-gestational-age infants (4.7 [2.......0-11.0]). There was no difference in rates of small-for-gestational-age infants. Significant predictors for birth weight (determined by multiple linear regression) were gestational weight gain, 2-h OGTT result, pre-gestational BMI, maternal age, gestational age, and smoking. CONCLUSIONS: Increasing weight gain in obese women...

Cognition and procedure representational requirements for predictive human performance models

Science.gov (United States)

Corker, K.

1992-01-01

Models and modeling environments for human performance are becoming significant contributors to early system design and analysis procedures. Issues of levels of automation, physical environment, informational environment, and manning requirements are being addressed by such man/machine analysis systems. The research reported here investigates the close interaction between models of human cognition and models that described procedural performance. We describe a methodology for the decomposition of aircrew procedures that supports interaction with models of cognition on the basis of procedures observed; that serves to identify cockpit/avionics information sources and crew information requirements; and that provides the structure to support methods for function allocation among crew and aiding systems. Our approach is to develop an object-oriented, modular, executable software representation of the aircrew, the aircraft, and the procedures necessary to satisfy flight-phase goals. We then encode in a time-based language, taxonomies of the conceptual, relational, and procedural constraints among the cockpit avionics and control system and the aircrew. We have designed and implemented a goals/procedures hierarchic representation sufficient to describe procedural flow in the cockpit. We then execute the procedural representation in simulation software and calculate the values of the flight instruments, aircraft state variables and crew resources using the constraints available from the relationship taxonomies. The system provides a flexible, extensible, manipulative and executable representation of aircrew and procedures that is generally applicable to crew/procedure task-analysis. The representation supports developed methods of intent inference, and is extensible to include issues of information requirements and functional allocation. We are attempting to link the procedural representation to models of cognitive functions to establish several intent inference methods

Determination of the STIS CCD Gain

Science.gov (United States)

Riley, Allyssa; Monroe, TalaWanda; Lockwood, Sean

2016-09-01

This report summarizes the analysis and absolute gain results of the STIS Cycle 23 special calibration program 14424 that was designed to measure the gain of amplifiers A, C and D at nominal gain settings of 1 and 4 e-/DN. We used the mean-variance technique and the results indicate a mean-variance technique.

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

Phase and gain control policies for robust active vibration control of flexible structures

International Nuclear Information System (INIS)

Zhang, K; Ichchou, M N; Scorletti, G; Mieyeville, F

2013-01-01

The interest of this paper is to develop a general and systematic robust control methodology for active vibration control of flexible structures. For this purpose, first phase and gain control policies are proposed to impose qualitative frequency-dependent requirements on the controller to consider a complete set of control objectives. Then the proposed control methodology is developed by employing phase and gain control policies in the dynamic output feedback H ∞  control: according to the set of control objectives, phase and gain control policies incorporate necessary weighting functions and determine them in a rational and systematic way; on the other hand, with the appropriate weighting functions efficient H ∞  control algorithms can automatically realize phase and gain control policies and generate a satisfactory H ∞  controller. The proposed control methodology can be used for both SISO and MIMO systems with collocated or non-collocated sensors and actuators. In this paper, it is validated on a non-collocated piezoelectric cantilever beam. Both numerical simulations and experimental results demonstrate the effectiveness of the proposed control methodology. (paper)

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

different values of average wind speed, controller synthesis is performed in two ways: one applying the desired values to the stability reserve, and the other requiring the minimization of a performance criterion, aimed at reducing mechanical stress, while the controller parameters are kept in an area that ensures admissible values to the stability reserve. This second way allows obtaining a solution for designing a simple classic controller, dedicated to large wind turbines, to which may be imposed requirements for mechanical fatigue mitigation. The proposed solutions are backed by numerical results obtained through numerical simulation

Nonunity gain minimal-disturbance measurement

DEFF Research Database (Denmark)

Sabuncu, Metin; Mišta, L.; Fiurášek, J.

2007-01-01

We propose and experimentally demonstrate an optimal nonunity gain Gaussian scheme for partial measurement of an unknown coherent state that causes minimal disturbance of the state. The information gain and the state disturbance are quantified by the noise added to the measurement outcomes...

Discussion on sealing performance required in disposal system. Hydraulic analysis of tunnel intersections

International Nuclear Information System (INIS)

Sugita, Yutaka; Takahashi, Yoshiaki; Uragami, Manabu; Kitayama, Kazumi; Fujita, Tomoo; Kawakami, Susumu; Yui, Mikazu; Umeki, Hiroyuki; Miyamoto, Yoichi

2005-09-01

The sealing performance of a repository must be considered in the safety assessment of the geological disposal system of the high-level radioactive waste. NUMO and JNC established 'Technical Commission on Sealing Technology of Repository' based on the cooperation agreement. The objectives of this commission are to present the concept on the sealing performance required in the disposal system and to develop the direction for future R and D programme for design requirements of closure components (backfilling material, clay plug, etc.) in the presented concept. In the first phase of this commission, the current status of domestic and international sealing technologies were reviewed; and repository components and repository environments were summarized subsequently, the hydraulic analysis of tunnel intersections, where a main tunnel and a disposal tunnel in a disposal panel meet, were performed, considering components in and around the engineered barrier system (EBS). Since all tunnels are connected in the underground facility, understanding the hydraulic behaviour of tunnel intersections is an important issue to estimate migration of radionuclides from the EBS and to evaluate the required sealing performance in the disposal system. In the analytical results, it was found that the direction of hydraulic gradient, hydraulic conductivities of concrete and backfilling materials and the position of clay plug had impact on flow condition around the EBS. (author)

Characterization of NPP Visible/Infrared Imager Radiometer Suite (VIIRS) Reflective Solar Bands Dual Gain Anomaly

Science.gov (United States)

Lee, Shihyan; McIntire, Jeff; Oudari, Hassan

2012-01-01

The Visible/Infrared Imager Radiometer Suite (VIIRS) contains six dual gain bands in the reflective solar spectrum. The dual gain bands are designed to switch gain mode at pre-defined thresholds to achieve high resolution at low radiances while maintaining the required dynamic range for science. During pre-launch testing, an anomaly in the electronic response before transitioning from high to low gain was discovered and characterized. On-orbit, the anomaly was confirmed using MODIS data collected during Simultaneous Nadir Overpasses (SNOs). The analysis of the Earth scene data shows that dual gain anomaly can be determined at the orbital basis. To characterize the dual gain anomaly, the anomaly region and electronic offsets were tracked per week during the first 8 month of VIIRS operation. The temporal analysis shows the anomaly region can drift 20 DN and is impacted by detectors DC Restore. The estimated anomaly flagging regions cover 2.5 % of the high gain dynamic range and are consistent with prelaunch and on-orbit LUT. The prelaunch results had a smaller anomaly range (30-50 DN) and are likely the results of more stable electronics from the shorter data collection time. Finally, this study suggests future calibration efforts to focus on the anomaly's impact on science products and possible correction method to reduce uncertainties.

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.

L-Band Digital Aeronautical Communications System Engineering - Concepts of Use, Systems Performance, Requirements, and Architectures

Science.gov (United States)

Zelkin, Natalie; Henriksen, Stephen

2010-01-01

This NASA Contractor Report summarizes and documents the work performed to develop concepts of use (ConUse) and high-level system requirements and architecture for the proposed L-band (960 to 1164 MHz) terrestrial en route communications system. This work was completed as a follow-on to the technology assessment conducted by NASA Glenn Research Center and ITT for the Future Communications Study (FCS). ITT assessed air-to-ground (A/G) communications concepts of use and operations presented in relevant NAS-level, international, and NAS-system-level documents to derive the appropriate ConUse relevant to potential A/G communications applications and services for domestic continental airspace. ITT also leveraged prior concepts of use developed during the earlier phases of the FCS. A middle-out functional architecture was adopted by merging the functional system requirements identified in the bottom-up assessment of existing requirements with those derived as a result of the top-down analysis of ConUse and higher level functional requirements. Initial end-to-end system performance requirements were derived to define system capabilities based on the functional requirements and on NAS-SR-1000 and the Operational Performance Assessment conducted as part of the COCR. A high-level notional architecture of the L-DACS supporting A/G communication was derived from the functional architecture and requirements.

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)

Charge Gain, Voltage Gain, and Node Capacitance of the SAPHIRA Detector Pixel by Pixel

Science.gov (United States)

Pastrana, Izabella M.; Hall, Donald N. B.; Baker, Ian M.; Jacobson, Shane M.; Goebel, Sean B.

2018-01-01

The University of Hawai`i Institute for Astronomy has partnered with Leonardo (formerly Selex) in the development of HgCdTe linear mode avalanche photodiode (L-APD) SAPHIRA detectors. The SAPHIRA (Selex Avalanche Photodiode High-speed Infra-Red Array) is ideally suited for photon-starved astronomical observations, particularly near infrared (NIR) adaptive optics (AO) wave-front sensing. I have measured the stability, and linearity with current, of a 1.7-um (10% spectral bandpass) infrared light emitting diode (IR LED) used to illuminate the SAPHIRA and have then utilized this source to determine the charge gain (in e-/ADU), voltage gain (in uV/ADU), and node capacitance (in fF) for each pixel of the 320x256@24um SAPHIRA. These have previously only been averages over some sub-array. Determined from the ratio of the temporal averaged signal level to variance under constant 1.7-um LED illumination, I present the charge gain pixel-by-pixel in a 64x64 sub-array at the center of the active area of the SAPHIRA (analyzed separately as four 32x32 sub-arrays) to be about 1.6 e-/ADU (σ=0.5 e-/ADU). Additionally, the standard technique of varying the pixel reset voltage (PRV) in 10 mV increments and recording output frames for the same 64x64 subarray found the voltage gain per pixel to be about 11.7 uV/ADU (σ=0.2 uV/ADU). Finally, node capacitance was found to be approximately 23 fF (σ=6 fF) utilizing the aforementioned charge and voltage gain measurements. I further discuss the linearity measurements of the 1.7-um LED used in the charge gain characterization procedure.

Vestibulo-ocular reflex gain values in the suppression head impulse test of healthy subjects.

Science.gov (United States)

Rey-Martinez, Jorge; Thomas-Arrizabalaga, Izaskun; Espinosa-Sanchez, Juan Manuel; Batuecas-Caletrio, Angel; Trinidad-Ruiz, Gabriel; Matiño-Soler, Eusebi; Perez-Fernandez, Nicolas

2018-02-15

To assess whether there are differences in vestibulo-ocular reflex (VOR) gain for suppression head impulse (SHIMP) and head impulse (HIMP) video head impulse test paradigms, and if so, what are their causes. Prospective multicenter observational double-blind nonrandomized clinical study was performed by collecting 80 healthy subjects from four reference hospitals. SHIMP data was postprocessed to eliminate impulses in which early SHIMP saccades were detected. Differences between HIMP and SHIMP VOR gain values were statistically evaluated. Head impulse maximum velocity, gender, age, direction of impulse, and hospital center were considered as possible influential factors. A small significant statistical difference between HIMP and SHIMP VOR gain values was found on repeated measures analysis of variance (-0.05 ± 0.006, P gain values and did not find influence between gain values differences and maximum head impulse velocity. Both HIMP and SHIMP VOR gain values were significant lower (-0.09, P gain values not adequately explained by known gain modification factors. The persistence of this slight but significant difference indicates that there are more factors causing lower SHIMP VOR gain values. This difference must to be considered in further studies as well as in the clinical SHIMP testing protocols. We hypothesized that VOR phasic response inhibition could be the underlying cause of this difference. IIb. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

Self-reported causes of weight gain: among prebariatric surgery patients.

Science.gov (United States)

Ferguson, Sarah; Al-Rehany, Layla; Tang, Cathy; Gougeon, Lorraine; Warwick, Katie; Madill, Janet

2013-01-01

Bariatric surgery is accepted by the medical community as the most effective treatment for obesity; however, weight regain after surgery remains common. Long-term weight loss and weight maintenance may be aided when dietitians who provide perioperative care understand the causes of weight gain leading to bariatric surgery. In this study, the most common causes for weight gain were examined among prebariatric surgery patients. A retrospective chart review was conducted for 160 patients enrolled in a bariatric surgery program. Data were collected for 20 variables: puberty, pregnancy, menopause, change in living environment, change in job/career, financial problems, quitting smoking, drug or alcohol use, medical condition, surgery, injury affecting mobility, chronic pain, dieting, others' influence over diet, abuse, mental health condition, stress, death of a loved one, divorce/end of a relationship, and other causes. Frequency distribution and chi-square tests were performed using SPSS. Sixty-three percent of participants selected stress as a cause of weight gain, while 56% selected dieting. Significant differences existed between women and men in the selection of dieting and change in living environment. This information may allow dietitians to better identify causes for weight gain leading to bariatric surgery, and to address these causes appropriately before and after surgery.

Partial Adaptation of Obtained and Observed Value Signals Preserves Information about Gains and Losses.

Science.gov (United States)

Burke, Christopher J; Baddeley, Michelle; Tobler, Philippe N; Schultz, Wolfram

2016-09-28

Given that the range of rewarding and punishing outcomes of actions is large but neural coding capacity is limited, efficient processing of outcomes by the brain is necessary. One mechanism to increase efficiency is to rescale neural output to the range of outcomes expected in the current context, and process only experienced deviations from this expectation. However, this mechanism comes at the cost of not being able to discriminate between unexpectedly low losses when times are bad versus unexpectedly high gains when times are good. Thus, too much adaptation would result in disregarding information about the nature and absolute magnitude of outcomes, preventing learning about the longer-term value structure of the environment. Here we investigate the degree of adaptation in outcome coding brain regions in humans, for directly experienced outcomes and observed outcomes. We scanned participants while they performed a social learning task in gain and loss blocks. Multivariate pattern analysis showed two distinct networks of brain regions adapt to the most likely outcomes within a block. Frontostriatal areas adapted to directly experienced outcomes, whereas lateral frontal and temporoparietal regions adapted to observed social outcomes. Critically, in both cases, adaptation was incomplete and information about whether the outcomes arose in a gain block or a loss block was retained. Univariate analysis confirmed incomplete adaptive coding in these regions but also detected nonadapting outcome signals. Thus, although neural areas rescale their responses to outcomes for efficient coding, they adapt incompletely and keep track of the longer-term incentives available in the environment. Optimal value-based choice requires that the brain precisely and efficiently represents positive and negative outcomes. One way to increase efficiency is to adapt responding to the most likely outcomes in a given context. However, too strong adaptation would result in loss of precise

Gain and exposure scheduling to compensate for photorefractive neural-network weight decay

Science.gov (United States)

Goldstein, Adam A.; Petrisor, Gregory C.; Jenkins, B. Keith

1995-03-01

A gain and exposure schedule that theoretically eliminates the effect of photorefractive weight decay for the general class of outer-product neural-network learning algorithms (e.g., backpropagation, Widrow-Hoff, perceptron) is presented. This schedule compensates for photorefractive diffraction-efficiency decay by iteratively increasing the spatial-light-modulator transfer function gain and decreasing the weight-update exposure time. Simulation results for the scheduling procedure, as applied to backpropagation learning for the exclusive-OR problem, show improved learning performance compared with results for networks trained without scheduling.

Compact gain saturated plasma based X-ray lasers down to 6.9nm

Science.gov (United States)

Rocca, Jorge; Wang, Y.; Wang, S.; Rockwood, A.; Berrill, M.; Shlyaptsev, V.

2017-10-01

Plasma based soft x-ray amplifiers allow many experiments requiring bright, high energy soft x-ray laser pulses to be conducted in compact facilities. We have extended the wavelength of compact gain saturated x-ray lasers to 6.89 nm in a Ni-like Gd plasma generated by a Ti:Sa laser. Gain saturated laser operation was also obtained at 7.36 nm in Ni-like Sm. Isolectronic scaling and optimization of laser pre-pulse duration allowed us to also observe strong lasing at 6.6 nm and 6.1 nm in Ni-like Tb, and amplification at 6.4 nm and 5.89 nm in Ni-like Dy. The results were obtained by transient laser heating of solid targets with traveling wave excitation at progressively increased gracing incidence angles. We show that the optimum pump angle of incidence for collisional Ni-like lasers increases linearly with atomic number from Z =42 to Z =66, reaching 43 degrees for Ni-like Dy, in good agreement with hydrodynamic/atomic physics simulations. These results will enable single-shot nano-scale imaging and other application of sub-7 nm lasers to be performed at compact facilities. Work supported by Grant DE-FG02-4ER15592 of the Department of Energy, Office of Science, and by the National Science Foundation Grant ECCS 1509925.

Role of market information in gaining public acceptance

International Nuclear Information System (INIS)

Berman, A.B.

1992-01-01

The nuclear energy industry challenge to gain acceptance for its next generation of nuclear power plants is immense. If not the majority, then a vocal minority, has doubts about the technology, its need, or those who implement it. Perceptions about the nuclear industry are complex. These are due to the difficulty in understanding the technology itself, the trade-offs of benefits against repercussions, and well-publicized plant problems. The industry requires a continual flow of actionable and comprehensive market information as input for decision making. The cost of implementing misdirected strategies is high. If not sensitive to public needs, the cost is opposition to nuclear development based on faulty or unsubstantiated reasoning. This paper addresses the required market information flow. It is suggested that a market information system is necessary for timely and usable information to ensure understanding of industry developmental efforts

Heuristic Portfolio Trading Rules with Capital Gain Taxes

DEFF Research Database (Denmark)

Fischer, Marcel; Gallmeyer, Michael

2016-01-01

We study the out-of-sample performance of portfolio trading strategies used when an investor faces capital gain taxation and proportional transaction costs. Overlaying simple tax trading heuristics on trading strategies improves out-of-sample performance. For medium to large transaction costs......, no trading strategy can outperform a 1/N trading strategy augmented with a tax heuristic, not even the most tax and transaction cost-efficient buy-and-hold strategy. Overall, the best strategy is 1/N augmented with a heuristic that allows for a fixed deviation in absolute portfolio weights. Our results thus...... show that the best trading strategies balance diversification considerations and tax considerations....

Fuzzy gain scheduling of velocity PI controller with intelligent learning algorithm for reactor control

International Nuclear Information System (INIS)

Kim, Dong Yun; Seong, Poong Hyun

1996-01-01

In this study, we proposed a fuzzy gain scheduler with intelligent learning algorithm for a reactor control. In the proposed algorithm, we used the gradient descent method to learn the rule bases of a fuzzy algorithm. These rule bases are learned toward minimizing an objective function, which is called a performance cost function. The objective of fuzzy gain scheduler with intelligent learning algorithm is the generation of adequate gains, which minimize the error of system. The condition of every plant is generally changed as time gose. That is, the initial gains obtained through the analysis of system are no longer suitable for the changed plant. And we need to set new gains, which minimize the error stemmed from changing the condition of a plant. In this paper, we applied this strategy for reactor control of nuclear power plant (NPP), and the results were compared with those of a simple PI controller, which has fixed gains. As a result, it was shown that the proposed algorithm was superior to the simple PI controller

Air Force Officials did not Consistently Comply with Requirements for Assessing Contractor Performance

Science.gov (United States)

2016-01-29

31 Appendix B. Improvement in PAR Completion Statistics _________________________________ 33 vi...agencies must perform frequent evaluation of compliance with reporting requirements so they can readily identify delinquent past performance efforts...Reporting Program,” August 13, 2011 Appendixes DODIG-2016-043 │ 33 Appendix B Improvement in PAR Completion Statistics The Senate Armed Services Committee

Over-the-catheter precut to gain access to the biliary duct during ERCP rendezvous.

Science.gov (United States)

Manes, Gianpiero; Baratti, Cinzia; Ardizzone, Sandro; Ferla, Fabio; Spiropoulos, Jean; Corsi, Fabio; Foschi, Diego; Trabucchi, Emilio; Bianchi Porro, Gabriele

2008-10-01

Endoscopic retrograde cholangiopancreatography (ERCP) rendezvous during laparoscopic cholecystectomy is an efficient and safe method to treat cholecystocholedocholithiasis. Advancing a guidewire through the cystic duct into the duodenum and withdrawing it in the accessory channel of duodenoscope may be, however, laborious. Moreover, rendezvous performed in the typical manner needs the use of several costly accessories. We herein describe a simpler and cheaper method to gain access to the biliary duct at rendezvous. Twenty-four consecutive patients undergoing ERCP rendezvous during laparoscopic cholecystectomy were considered. A catheter was introduced in the cystic duct and advanced into the duodenum. Access to the bile duct was than achieved by means of a precut sphincterotomy performed over the catheter emerging from the papilla. Cannulation was successful in all but two patients, in whom ERCP was performed in the conventional manner. The only complication was a case of mild post-sphincterotomy bleeding. In comparison with the typical rendezvous technique our procedure allowed savings of about 250, since its performance only requires a catheter and a knife sphincterotome. Over-the-catheter precut during ERCP rendezvous is a feasible and safe method which avoids the need for the manipulation of several accessories and guidewires, and thus results in money and time savings.

Sensor Performance Requirements for the Retrieval of Atmospheric Aerosols by Airborne Optical Remote Sensing

Directory of Open Access Journals (Sweden)

Klaus I. Itten

2008-03-01

Full Text Available This study explores performance requirements for the retrieval of the atmospheric aerosol optical depth (AOD by airborne optical remote sensing instruments. Independent of any retrieval techniques, the calculated AOD retrieval requirements are compared with the expected performance parameters of the upcoming hyperspectral sensor APEX at the reference wavelength of 550nm. The AOD accuracy requirements are defined to be capable of resolving transmittance differences of 0.01 to 0.04 according to the demands of atmospheric corrections for remote sensing applications. For the purposes of this analysis, the signal at the sensor level is simulated by radiation transfer equations. The resulting radiances are translated into the AOD retrieval sensitivity (Δτλaer and compared to the available measuring sensitivity of the sensor (NE ΔLλsensor. This is done for multiple signal-to-noise ratios (SNR and surface reflectance values. It is shown that an SNR of 100 is adequate for AOD retrieval at 550nm under typical remote sensing conditions and a surface reflectance of 10% or less. Such dark surfaces require the lowest SNR values and therefore offer the best sensitivity for measuring AOD. Brighter surfaces with up to 30% reflectance require an SNR of around 300. It is shown that AOD retrieval for targets above 50% surface reflectance is more problematic with the current sensor performance as it may require an SNR larger than 1000. In general, feasibility is proven for the analyzed cases under simulated conditions.

Controlling gain one photon at a time

Science.gov (United States)

Schwartz, Gregory W; Rieke, Fred

2013-01-01

Adaptation is a salient property of sensory processing. All adaptational or gain control mechanisms face the challenge of obtaining a reliable estimate of the property of the input to be adapted to and obtaining this estimate sufficiently rapidly to be useful. Here, we explore how the primate retina balances the need to change gain rapidly and reliably when photons arrive rarely at individual rod photoreceptors. We find that the weakest backgrounds that decrease the gain of the retinal output signals are similar to those that increase human behavioral threshold, and identify a novel site of gain control in the retinal circuitry. Thus, surprisingly, the gain of retinal signals begins to decrease essentially as soon as background lights are detectable; under these conditions, gain control does not rely on a highly averaged estimate of the photon count, but instead signals from individual photon absorptions trigger changes in gain. DOI: http://dx.doi.org/10.7554/eLife.00467.001 PMID:23682314

Diets formulated on total or digestible amino acid basis with different energy levels and physical form on broiler performance

Directory of Open Access Journals (Sweden)

A Maiorka

2005-03-01

Full Text Available We studied the effects of two different systems of expressing amino acid requirements (total - TAA or digestible - DAA, two energy levels (2,900 or 3,200 kcal of ME/kg and two physical forms (mash or pellet on the performance of male broilers from 21 to 42 d of age. Diets formulated on DAA basis improved feed conversion (p<0.001 and the conversion of consumed ME into body weight gain (p<0.001. Birds fed 3,200 kcal ME/kg presented better feed conversion (p<0.001, higher abdominal fat deposition (p<0.001 and worse conversion of consumed ME into body weight gain (p<0.001 as compared to birds fed 2,900 kcal ME/kg. Birds fed pelleted feed had higher feed intake (p<0.001, higher weight gain (p<0.001, better feed conversion (p<0.001, better conversion of consumed ME into body weight gain (p<0.001 and higher abdominal fat deposition (p<0.001. The results obtained in the present study suggest that feed formulation based on DAA is required when diets contain protein sources which amino acid digestibility is unreliable. Besides, pelleted feed improves performance parameters of broilers.

42 CFR 493.53 - Notification requirements for laboratories issued a certificate for provider-performed microscopy...

Science.gov (United States)

2010-10-01

... certificate for provider-performed microscopy (PPM) procedures. 493.53 Section 493.53 Public Health CENTERS... CERTIFICATION LABORATORY REQUIREMENTS Registration Certificate, Certificate for Provider-performed Microscopy... certificate for provider-performed microscopy (PPM) procedures. Laboratories issued a certificate for PPM...

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.

The Association between Weight Gain/Restoration and Bone Mineral Density in Adolescents with Anorexia Nervosa: A Systematic Review.

Science.gov (United States)

El Ghoch, Marwan; Gatti, Davide; Calugi, Simona; Viapiana, Ombretta; Bazzani, Paola Vittoria; Dalle Grave, Riccardo

2016-11-29

Reduced bone mineral density (BMD) is one of the most frequent medical complications of anorexia nervosa (AN). The purpose of this paper was to conduct a systematic review of the association between weight gain/restoration and BMD in adolescents with AN. Literature searches, study selection, method, and quality appraisal were performed independently by two authors, and data were collated using a narrative approach. Of the 1156 articles retrieved, 19 studies met the inclusion criteria, and their analysis revealed four main findings. First, six studies reported that weight gain and restoration are associated with BMD stabilization after one year of follow-up from baseline. Second, seven studies with longer follow-up periods (≈16 months) reported significant improvements in BMD measures. Third, one study showed that normalization of BMD can be achieved after ≈30-month follow-up of normal-weight maintenance. Fourth, another study showed that male adolescents with AN who achieve weight gain but remain underweight may experience further BMD loss, unlike their weight-restored counterparts (BMI ≥ 19 kg/m²), who show a significant increase in BMD and bone mineral accrual rates that double those of healthy male adolescents. The first two findings can be considered robust, as they are supported by strong evidence. The third and fourth findings, however, derive from single studies and therefore require further confirmation. The literature supports weight gain as an effective strategy for promoting BMD increase in adolescents with AN. However, this process is slow, and improvements do not become detectable until ≈16-month follow-up.

The Association between Weight Gain/Restoration and Bone Mineral Density in Adolescents with Anorexia Nervosa: A Systematic Review

Directory of Open Access Journals (Sweden)

Marwan El Ghoch

2016-11-01

Full Text Available Background: Reduced bone mineral density (BMD is one of the most frequent medical complications of anorexia nervosa (AN. The purpose of this paper was to conduct a systematic review of the association between weight gain/restoration and BMD in adolescents with AN. Methods: Literature searches, study selection, method, and quality appraisal were performed independently by two authors, and data were collated using a narrative approach. Results: Of the 1156 articles retrieved, 19 studies met the inclusion criteria, and their analysis revealed four main findings. First, six studies reported that weight gain and restoration are associated with BMD stabilization after one year of follow-up from baseline. Second, seven studies with longer follow-up periods (≈16 months reported significant improvements in BMD measures. Third, one study showed that normalization of BMD can be achieved after ≈30-month follow-up of normal-weight maintenance. Fourth, another study showed that male adolescents with AN who achieve weight gain but remain underweight may experience further BMD loss, unlike their weight-restored counterparts (BMI ≥ 19 kg/m2, who show a significant increase in BMD and bone mineral accrual rates that double those of healthy male adolescents. The first two findings can be considered robust, as they are supported by strong evidence. The third and fourth findings, however, derive from single studies and therefore require further confirmation. Conclusion: The literature supports weight gain as an effective strategy for promoting BMD increase in adolescents with AN. However, this process is slow, and improvements do not become detectable until ≈16-month follow-up.

A1.5 Fusion Performance

Energy Technology Data Exchange (ETDEWEB)

Amendt, P

2011-03-31

Analysis and radiation hydrodynamics simulations for expected high-gain fusion target performance on a demonstration 1-GWe Laser Inertial Fusion Energy (LIFE) power plant in the mid-2030s timeframe are presented. The required laser energy driver is 2.2 MJ at a 0.351-{micro}m wavelength, and a fusion target gain greater than 60 at a repetition rate of 16 Hz is the design goal for economic and commercial attractiveness. A scaling-law analysis is developed to benchmark the design parameter space for hohlraum-driven central hot-spot ignition. A suite of integrated hohlraum simulations is presented to test the modeling assumptions and provide a basis for a near-term experimental resolution of the key physics uncertainties on the National Ignition Facility (NIF). The NIF is poised to demonstrate ignition by 2012 based on the central hot spot (CHS) mode of ignition and propagating thermonuclear burn [1]. This immediate prospect underscores the imperative and timeliness of advancing inertial fusion as a carbon-free, virtually limitless source of energy by the mid-21st century to substantially offset fossil fuel technologies. To this end, an intensive effort is underway to leverage success at the NIF and to provide the foundations for a prototype 'LIFE.1' engineering test facility by {approx}2025, followed by a commercially viable 'LIFE.2' demonstration power plant operating at 1 GWe by {approx}2035. The current design goal for LIFE.2 is to accommodate {approx}2.2 MJ of laser energy (entering the high-Z radiation enclosure or 'hohlraum') at a 0.351-{micro}m wavelength operating at a repetition rate of 16 Hz and to provide a fusion target yield of 132 MJ. To achieve this design goal first requires a '0-d' analytic gain model that allows convenient exploration of parameter space and target optimization. This step is then followed by 2- and 3-dimensional radiation-hydrodynamics simulations that incorporate laser beam transport, x

The performance of neutron scattering spectrometers at a long-pulse spallation source

International Nuclear Information System (INIS)

Pynn, R.

1995-01-01

The first conclusion the author wants to draw is that comparison of the performance of neutron scattering spectrometers at CW and pulsed sources is simpler for long-pulsed sources than it is for the short-pulse variety. Even though detailed instrument design and assessment will require Monte Carlo simulations (which have already been performed at Los Alamos for SANS and reflectometry), simple arguments are sufficient to assess the approximate performance of spectrometers at an LPSS and to support the contention that a 1 MW long-pulse source can provide attractive performance, especially for instrumentation designed for soft-condensed-matter science. Because coupled moderators can be exploited at such a source, its time average cold flux is equivalent to that of a research reactor with a power of about 15 MW, so only a factor of 4 gain from source pulsing is necessary to obtain performance that is comparable with the ILL. In favorable cases, the gain from pulsing can be even more than this, approaching the limit set by the peak flux, giving about 4 times the performance of the ILL. Because of its low duty factor, an LPSS provides the greatest performance gains for relatively low resolution experiments with cold neutrons. It should thus be considered complementary to short pulse sources which are most effective for high resolution experiments using thermal or epithermal neutrons

Scaling a network with positive gains to a lossy or gainy network

NARCIS (Netherlands)

Koene, J.

1979-01-01

Necessary and sufficient conditions are presented under which it is possible to scale a network with positive gains to a lossy or a gainy network. A procedure to perform such a scaling operation is given.

Applying Required Navigation Performance Concept for Traffic Management of Small Unmanned Aircraft Systems

Science.gov (United States)

Jung, Jaewoo; D'Souza, Sarah N.; Johnson, Marcus A.; Ishihara, Abraham K.; Modi, Hemil C.; Nikaido, Ben; Hasseeb, Hashmatullah

2016-01-01

In anticipation of a rapid increase in the number of civil Unmanned Aircraft System(UAS) operations, NASA is researching prototype technologies for a UAS Traffic Management (UTM) system that will investigate airspace integration requirements for enabling safe, efficient low-altitude operations. One aspect a UTM system must consider is the correlation between UAS operations (such as vehicles, operation areas and durations), UAS performance requirements, and the risk to people and property in the operational area. This paper investigates the potential application of the International Civil Aviation Organizations (ICAO) Required Navigation Performance (RNP) concept to relate operational risk with trajectory conformance requirements. The approach is to first define a method to quantify operational risk and then define the RNP level requirement as a function of the operational risk. Greater operational risk corresponds to more accurate RNP level, or smaller tolerable Total System Error (TSE). Data from 19 small UAS flights are used to develop and validate a formula that defines this relationship. An approach to assessing UAS-RNP conformance capability using vehicle modeling and wind field simulation is developed to investigate how this formula may be applied in a future UTM system. The results indicate the modeled vehicles flight path is robust to the simulated wind variation, and it can meet RNP level requirements calculated by the formula. The results also indicate how vehicle-modeling fidelity may be improved to adequately verify assessed RNP level.

Study of the MWPC gas gain behaviour as a function of the gas pressure and temperature

CERN Document Server

Pinci, D

2005-01-01

The Muon System of the LHCb experiment is composed of five detection stations (M1-M5) equipped with 1368 Multi-Wire Proportional Chambers (MWPC) and 24 Triple-GEM detectors. The Multi Wire Proportional Chamber (MWPC) performances (detection efficiency, time resolution, pad-cluster size and ageing properties) are heavily dependent on the gas gain. The chamber gain depends on the gas density and therefore on the gas temperature and pressure. The impact of the environmental parameters on the MWPC gain has been studied in detail. The results, togheter with a simple method proposed to account for the gain variations, are reported in this note. The absolute gas gain at the testing voltage of 2750 V was also measured to be (1.2 +- 0.1)*10^5.

A model to predict solar heat gains to outside wine tanks

Energy Technology Data Exchange (ETDEWEB)

Delves, T.; Weedon, M.; Louis, J. [Charles Sturt Univ., Wagga Wagga, NSW (Australia). National Wine and Grape Industry Centre

2006-07-01

Although there are many software and simulation tools for calculating solar heat gains to residential and commercial buildings, little information is available to predict the heating effect of products stored in outdoor facilities. In older wineries where wine is stored outdoors in stainless steel tanks, solar heat gains can result in unwanted warming of the wine. This not only ruins the wine quality, but places an additional load on the winery refrigeration system. In this study, experiments were performed to determine the effect of solar radiation and ambient conditions on the heating of wine stored in outside tanks. Trials were conducted on a 25 kL outdoor stainless steel tank at Rutherglen, Australia. In order to incorporate the effect of shading from adjacent tanks, trials were also conducted at Wagga Wagga, Australia, on a group of tanks where mutual shading was present. Each tank was fitted with sensors to study the effect of morning, afternoon and mid-day shading. A mathematical model was developed to predict the amount of solar heat load received by the tank. The model considered the effect of seasonal variations in radiation intensity, day length and sun angle. The model incorporated the size, spacing and orientation of the tanks as well as solar considerations such as time of year and latitude. This paper also presented background information on the solar radiation received by the earth. Solar radiation comprises direct radiation and diffuse radiation. Direct radiation refers to direct sunlight, travelling in parallel rays from the sun, while diffuse radiation refers to radiation which has been scattered by the atmosphere. In most cases, direct radiation is dominant, but both radiations are considered when calculating solar energy gains. The solar heating of the 25 kL tank of wine was calculated by isolating the solar heating from other heat flows. Fermentation was complete and no refrigeration was applied to the tank during the 5 days of the trial. Only

A survey of clinical performance skills requirements in medical radiation technology

International Nuclear Information System (INIS)

Rowntree, P.A.; Veitch, J.D.

1993-01-01

This paper outlines the reasons behind carry out a study of clinical performance skills requirements and the method being used to gather data. It describes the changes which have occurred in radiographer education in Queensland, the broader impact brought about by changes in professional body requirements and the development of a Competency based Standards Document for the profession. The paper provides examples of the survey design and layout being developed for distribution to third year students in the Medical Imaging Technology major of the Bachelor of Applied Science (Medical Radiation Technology) Queensland University of Technology, graduates and clinical departments in Queensland. 1 tab., 1 fig

Clinical Medicine: Endocrinology and Diabetes: Gender-associated Differences in Weight Gain, Insulin Requirement and Metabolic control in Newly Insulin-treated Type 2 Diabetic Patients with Secondary Sulfonylurea Failure–-a One-year Observation

Directory of Open Access Journals (Sweden)

Georg Biesenbach

2009-01-01

Full Text Available Objective The aim of the present study was to determine differences between male and female type 2 diabetic patients concerning body weight, metabolic control, insulin requirement and prevalence of vascular diseases during the first year insulin therapy. Patients and Methods We investigated 102 newly insulin-treated type 2 diabetic patients (60 female with secondary sulfonylurea failure. Observation period was the first year insulin therapy. We compared BMI, HbA1c, lipids and insulin requirement at the begin and after one year, C-peptide and prevalence of vascular diseases at the start of insulin therapy. Results At the start of insulin substitution, omen had a higher BMI (27 + 3 versus 25 + 3; p < 0.05. Women also required a higher insulin dose than did men (28 + 6 versus 24 + 6 IU/day Mean HbA1c and cholesterol levels were similar in both groups whereas triglycerides were higher in women (244 + 88 versus 203 + 76 mg/dl; p < 0.05. Both groups achieved a similar gain in body weight after one year (+2.5% versus +2.6%; NS. HbA1c decreased from 9.2 + 1.1 to 7.4% + 0.9% (–19% in women and from 9.4 + 1.1 to 7.5% + 1.0% (–20% in men. The prevalence of vascular diseases was not significantly different in both groups. Conclusions At the start of insulin therapy female type 2 diabetic patients showed a significant higher BMI and a higher insulin requirement than male patients. The metabolic control was similar in men and women, only the triglycerides were higher in the female patients. Weight gain and increase of needed insulin as well as prevalence of macroangiopathy were the same in both groups.

Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

Science.gov (United States)

Jansen, Ralph H.; Brown, Gerald V.; Felder, James L.; Duffy, Kirsten P.

2016-01-01

The purpose of this paper is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

Insulin-associated weight gain in obese type 2 diabetes mellitus patients: What can be done?

Science.gov (United States)

Brown, Adrian; Guess, Nicola; Dornhorst, Anne; Taheri, Shahrad; Frost, Gary

2017-12-01

Insulin therapy (IT) is initiated for patients with type 2 diabetes mellitus when glycaemic targets are not met with diet and other hypoglycaemic agents. The initiation of IT improves glycaemic control and reduces the risk of microvascular complications. There is, however, an associated weight gain following IT, which may adversely affect diabetic and cardiovascular morbidity and mortality. A 3 to 9 kg insulin-associated weight gain (IAWG) is reported to occur in the first year of initiating IT, predominantly caused by adipose tissue. The potential causes for this weight gain include an increase in energy intake linked to a fear of hypoglycaemia, a reduction in glycosuria, catch-up weight, and central effects on weight and appetite regulation. Patients with type 2 diabetes who are receiving IT often have multiple co-morbidities, including obesity, that are exacerbated by weight gain, making the management of their diabetes and obesity challenging. There are several treatment strategies for patients with type 2 diabetes, who require IT, that attenuate weight gain, help improve glycaemic control, and help promote body weight homeostasis. This review addresses the effects of insulin initiation and intensification on IAWG, and explores its potential underlying mechanisms, the predictors for this weight gain, and the available treatment options for managing and limiting weight gain. © 2017 John Wiley & Sons Ltd.

Audit of Gaining Early Awareness and Readiness for Undergraduate Programs. Final Audit Report.

Science.gov (United States)

Office of Inspector General (ED), Washington, DC.

An audit was conducted to determine whether the U.S. Department of Education had implemented adequate management controls to administer the Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) in accordance with legislative, regulatory, and internal administrative requirements. The focus was on the fiscal year 2000 grant…

Experience gained in enhancing operational safety at ComEd's nuclear power plants

International Nuclear Information System (INIS)

Elias, D.

1997-01-01

The following aspects of experience gained in enhancing operational safety at Comed's nuclear power plants are discussed: nuclear safety policy; centralization/decentralization; typical nuclear operating organization; safety review boards; human performance enhancement; elements of effective nuclear oversight

The increase in physical performance and gain in lean and fat mass occur in prepubertal children independent of mode of school transportation. One year data from the prospective controlled Pediatric Osteoporosis Prevention (POP) Study

Science.gov (United States)

2009-01-01

Background The aim of this 12-month study in pre-pubertal children was to evaluate the effect of school transportation on gain in lean and fat mass, muscle strength and physical performance. Methods Ninety-seven girls and 133 boys aged 7-9 years from the Malmö Pediatric Osteoporosis Prevention Study were included. Regional lean and fat mass were assessed by dual energy X-ray absorptiometry, isokinetic peak torque of knee extensors and flexors by a computerised dynamometer and physical performance by vertical jump height. Level of physical activity was assessed by accelerometers. The 12-month changes in children who walked or cycled to school were compared with changes in those who travelled by bus or car. Results There were no differences in baseline or annual changes in lean or fat mass gain, muscle strength or physical performance between the two groups. All children reached the internationally recommended level of 60 minutes per day of moderate or high physical activity by accelerometers. Conclusion The choice of school transportation in pre-pubertal children seems not to influence the gain in lean and fat mass, muscle strength or functional ability, probably as the everyday physical activity is so high that the mode of school transportation contributes little to the total level of activity.

High Gain Antenna Calibration on Three Spacecraft

Science.gov (United States)

Hashmall, Joseph A.

2011-01-01

This paper describes the alignment calibration of spacecraft High Gain Antennas (HGAs) for three missions. For two of the missions (the Lunar Reconnaissance Orbiter and the Solar Dynamics Observatory) the calibration was performed on orbit. For the third mission (the Global Precipitation Measurement core satellite) ground simulation of the calibration was performed in a calibration feasibility study. These three satellites provide a range of calibration situations-Lunar orbit transmitting to a ground antenna for LRO, geosynchronous orbit transmitting to a ground antenna fer SDO, and low Earth orbit transmitting to TDRS satellites for GPM The calibration results depend strongly on the quality and quantity of calibration data. With insufficient data the calibration Junction may give erroneous solutions. Manual intervention in the calibration allowed reliable parameters to be generated for all three missions.

Performance Characterization of the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) CCD Cameras

Science.gov (United States)

Joiner, R. K.; Kobayashi, K.; Winebarger, A. R.; Champey, P. R.

2014-12-01

The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a sounding rocket instrument which is currently being developed by NASA's Marshall Space Flight Center (MSFC) and the National Astronomical Observatory of Japan (NAOJ). The goal of this instrument is to observe and detect the Hanle effect in the scattered Lyman-Alpha UV (121.6nm) light emitted by the Sun's Chromosphere to make measurements of the magnetic field in this region. In order to make accurate measurements of this effect, the performance characteristics of the three on-board charge-coupled devices (CCDs) must meet certain requirements. These characteristics include: quantum efficiency, gain, dark current, noise, and linearity. Each of these must meet predetermined requirements in order to achieve satisfactory performance for the mission. The cameras must be able to operate with a gain of no greater than 2 e-/DN, a noise level less than 25e-, a dark current level which is less than 10e-/pixel/s, and a residual non-linearity of less than 1%. Determining these characteristics involves performing a series of tests with each of the cameras in a high vacuum environment. Here we present the methods and results of each of these performance tests for the CLASP flight cameras.

Using Decision Tree Analysis to Understand Foundation Science Student Performance. Insight Gained at One South African University

Science.gov (United States)

Kirby, Nicola Frances; Dempster, Edith Roslyn

2014-11-01

The Foundation Programme of the Centre for Science Access at the University of KwaZulu-Natal, South Africa provides access to tertiary science studies to educationally disadvantaged students who do not meet formal faculty entrance requirements. The low number of students proceeding from the programme into mainstream is of concern, particularly given the national imperative to increase participation and levels of performance in tertiary-level science. An attempt was made to understand foundation student performance in a campus of this university, with the view to identifying challenges and opportunities for remediation in the curriculum and processes of selection into the programme. A classification and regression tree analysis was used to identify which variables best described student performance. The explanatory variables included biographical and school-history data, performance in selection tests, and socio-economic data pertaining to their year in the programme. The results illustrate the prognostic reliability of the model used to select students, raise concerns about the inefficiency of school performance indicators as a measure of students' academic potential in the Foundation Programme, and highlight the importance of accommodation arrangements and financial support for student success in their access year.

Changes in corticospinal excitability during consolidation predict acute exercise-induced off-line gains in procedural memory

DEFF Research Database (Denmark)

Ostadan, Fatemeh; Centeno, Carla; Daloze, Jean-Felix

2016-01-01

A single bout of cardiovascular exercise performed immediately after practicing a motor task improves the long-term retention of the skill through an optimization of memory consolidation. However, the specific brain mechanisms underlying the effects of acute cardiovascular exercise on procedural...... exercise correlated with the magnitude of off-line gains in skill level assessed in a retention test performed 8h after motor practice. A single bout of exercise modulates short-term neuroplasticity mechanisms subserving consolidation processes that predict off-line gains in procedural memory....... memory are poorly understood. We sought to determine if a single bout of exercise modifies corticospinal excitability (CSE) during the early stages of memory consolidation. In addition, we investigated if changes in CSE are associated with exercise-induced off-line gains in procedural memory...

Using Multilayered Substrate Integrated Waveguide to Design Microwave Gain Equalizer

Directory of Open Access Journals (Sweden)

Yongfei Wang

2014-01-01

Full Text Available This paper presents the design and experiment of a novel microwave gain equalizer based on the substrate integrated waveguide (SIW technique. The proposed equalizer is formed by an SIW loaded by SIW resonators, which has very compact structure and can compensate for gain slope of microwave systems. Equivalent circuit analysis is given about the proposed structure for a better insight into the structure’s response. A Ku-Band equalizer with four SIW resonators is simulated and fabricated with a multilayer printed circuit board process. The measured results show good performance and agreement with the simulated results; an attenuation slope of −4.5 dB over 12.5–13.5 GHz is reached with a size reduction of 76%.

Decomposition of potential efficiency gains from hospital mergers in Greece.

Science.gov (United States)

Flokou, Angeliki; Aletras, Vassilis; Niakas, Dimitris

2017-12-01

This paper evaluates the technical efficiency of 71 Greek public hospitals and examines potential efficiency gains from 13 candidate mergers among them. Efficiency assessments are performed using bootstrapped Data Envelopment Analysis (DEA) whilst merger analysis is conducted by applying the Bogetoft and Wang methodology which allows the overall potential merger gains to be decomposed into three main components of inefficiency, namely technical (or learning), scope (or harmony) and scale (or size) effects. Thus, the analysis provides important insights not only on the magnitude of the potential total efficiency gains but also on their sources. The overall analysis is conducted in the context of a complete methodological framework where methods for outlier detection, returns to scale identification, and bias corrections for DEA estimations are also applied. Mergers are analyzed under the assumptions of constant, variable and non-decreasing returns to scale in an input oriented DEA model with three inputs and three outputs. The main finding of the study indicates that almost all mergers show substantial potential room for efficiency improvement, which is mainly attributed to the pre-merger technical inefficiencies of the individual hospitals and therefore it might be possible to be achieved without the need of implementing full-scale mergers. The same -though, at a lower extent- applies to the harmony effect whilst the size effect shows marginal or even negative gains.

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 ...

Construction products performances and basic requirements for fire safety of facades in energy rehabilitation of buildings

Directory of Open Access Journals (Sweden)

Laban Mirjana Đ.

2015-01-01

Full Text Available Construction product means any product or kit which is produced and placed on the market for incorporation in a permanent manner in construction works, or parts thereof, and the performance of which has an effect on the performance of the construction works with respect to the basic requirements for construction works. Safety in case of fire and Energy economy and heat retention represent two among seven basic requirements which building has to meet according to contemporary technical rules on planning and construction. Performances of external walls building materials (particularly reaction to fire could significantly affect to fire spread on the façade and other building parts. Therefore, façade shaping and materialization in building renewal process, has to meet the fire safety requirement, as well as the energy requirement. Brief survey of fire protection regulations development in Serbia is presented in the paper. Preventive measures for fire risk reduction in building façade energy renewal are proposed according to contemporary fire safety requirements.

What drives sleep-dependent memory consolidation: greater gain or less loss?

Science.gov (United States)

Fenn, Kimberly M; Hambrick, David Z

2013-06-01

When memory is tested after a delay, performance is typically better if the retention interval includes sleep. However, it is unclear what accounts for this well-established effect. It is possible that sleep enhances the retrieval of information, but it is also possible that sleep protects against memory loss that normally occurs during waking activity. We developed a new research approach to investigate these possibilities. Participants learned a list of paired-associate items and were tested on the items after a 12-h interval that included waking or sleep. We analyzed the number of items gained versus the number of items lost across time. The sleep condition showed more items gained and fewer items lost than did the wake condition. Furthermore, the difference between the conditions (favoring sleep) in lost items was greater than the difference in gain, suggesting that loss prevention may primarily account for the effect of sleep on declarative memory consolidation. This finding may serve as an empirical constraint on theories of memory consolidation.

Contrasting losses and gains increases the predictability of behavior by frontal EEG asymmetry

Science.gov (United States)

Telpaz, Ariel; Yechiam, Eldad

2014-01-01

Frontal asymmetry measured at rest using EEG is considered a stable marker of approach-avoidance behaviors and risk taking. We examined whether without salient cues of attention in the form of losses, predictability is reduced. Fifty-seven participants performed an experiential decision task in a gain-only, loss-only, and mixed (gains and losses) condition. Increased risk taking on the part of individuals with relatively high left frontal activation, as denoted by the Alpha band, was only observed in the task involving both gains and losses. Event-related potential analysis sheds light on the processes leading to this pattern. Left-frontal dominant individuals had increased fronto-central P300 activation following risky compared to safe outcomes, while right-frontal dominant individuals did not show a P300 difference following safe and risky outcomes. This interaction also only emerged when losses were contrasted with gains. The findings highlight the sensitivity of behavioral predictability to cues of valence. PMID:24817845

Nova Upgrade: A proposed ICF facility to demonstrate ignition and gain, revision 1

Science.gov (United States)

1992-07-01

The present objective of the national Inertial Confinement Fusion (ICF) Program is to determine the scientific feasibility of compressing and heating a small mass of mixed deuterium and tritium (DT) to conditions at which fusion occurs and significant energy is released. The potential applications of ICF will be determined by the resulting fusion energy yield (amount of energy produced) and gain (ratio of energy released to energy required to heat and compress the DT fuel). Important defense and civilian applications, including weapons physics, weapons effects simulation, and ultimately the generation of electric power will become possible if yields of 100 to 1,000 MJ and gains exceeding approximately 50 can be achieved. Once ignition and propagating bum producing modest gain (2 to 10) at moderate drive energy (1 to 2 MJ) has been achieved, the extension to high gain (greater than 50) is straightforward. Therefore, the demonstration of ignition and modest gain is the final step in establishing the scientific feasibility of ICF. Lawrence Livermore National Laboratory (LLNL) proposes the Nova Upgrade Facility to achieve this demonstration by the end of the decade. This facility would be constructed within the existing Nova building at LLNL for a total cost of approximately $400 M over the proposed FY 1995-1999 construction period. This report discusses this facility.

Examining the provisional guidelines for weight gain in twin pregnancies: a retrospective cohort study.

Science.gov (United States)

Lutsiv, Olha; Hulman, Adam; Woolcott, Christy; Beyene, Joseph; Giglia, Lucy; Armson, B Anthony; Dodds, Linda; Neupane, Binod; McDonald, Sarah D

2017-09-29

Weight gain during pregnancy has an important impact on maternal and neonatal health. Unlike the Institute of Medicine (IOM) recommendations for weight gain in singleton pregnancies, those for twin gestations are termed "provisional", as they are based on limited data. The objectives of this study were to determine the neonatal and maternal outcomes associated with gaining weight below, within and above the IOM provisional guidelines on gestational weight gain in twin pregnancies, and additionally, to explore ranges of gestational weight gain among women who delivered twins at the recommended gestational age and birth weight, and those who did not. A retrospective cohort study of women who gave birth to twins at ≥20 weeks gestation, with a birth weight ≥ 500 g was conducted in Nova Scotia, Canada (2003-2014). Our primary outcome of interest was small for gestational age (gain were used to categorize women as gaining below, within, or above guidelines. We performed traditional regression analyses for maternal outcomes, and to account for the correlated nature of the neonatal outcomes in twins, we used generalized estimating equations (GEE). A total of 1482 twins and 741 mothers were included, of whom 27%, 43%, and 30% gained below, within, and above guidelines, respectively. The incidence of small for gestational age in these three groups was 30%, 21%, and 20%, respectively, and relative to gaining within guidelines, the adjusted odds ratios were 1.44 (95% CI 1.01-2.06) for gaining below and 0.92 (95% CI 0.62-1.36) for gaining above. The gestational weight gain in women who delivered twins at 37-42 weeks with average birth weight ≥ 2500 g and those who delivered twins outside of the recommend ranges were comparable to each other and the IOM recommendations. While gestational weight gain below guidelines for twins was associated with some adverse neonatal outcomes, additional research exploring alternate ranges of gestational weight gain in twin

Validation of Tilt Gain under Realistic Path Loss Model and Network Scenario

DEFF Research Database (Denmark)

Nguyen, Huan Cong; Rodriguez, Ignacio; Sørensen, Troels Bundgaard

2013-01-01

Despite being a simple and commonly-applied radio optimization technique, the impact on practical network performance from base station antenna downtilt is not well understood. Most published studies based on empirical path loss models report tilt angles and performance gains that are far higher...... than practical experience suggests. We motivate in this paper, based on a practical LTE scenario, that the discrepancy partly lies in the path loss model, and shows that a more detailed semi-deterministic model leads to both lower gains in terms of SINR, outage probability and downlink throughput...... settings, including the use of electrical and/or mechanical antenna downtilt, and therefore it is possible to find multiple optimum tilt profiles in a practical case. A broader implication of this study is that care must be taken when using the 3GPP model to evaluate advanced adaptive antenna techniques...

Maternal obesity and gestational weight gain are risk factors for infant death.

Science.gov (United States)

Bodnar, Lisa M; Siminerio, Lara L; Himes, Katherine P; Hutcheon, Jennifer A; Lash, Timothy L; Parisi, Sara M; Abrams, Barbara

2016-02-01

Assessment of the joint and independent relationships of gestational weight gain and prepregnancy body mass index (BMI) on risk of infant mortality was performed. This study used Pennsylvania linked birth-infant death records (2003-2011) from infants without anomalies born to mothers with prepregnancy BMI categorized as underweight (n = 58,973), normal weight (n = 610,118), overweight (n = 296,630), grade 1 obesity (n = 147,608), grade 2 obesity (n = 71,740), and grade 3 obesity (n = 47,277). Multivariable logistic regression models stratified by BMI category were used to estimate dose-response associations between z scores of gestational weight gain and infant death after confounder adjustment. Infant mortality risk was lowest among normal-weight women and increased with rising BMI category. For all BMI groups except for grade 3 obesity, there were U-shaped associations between gestational weight gain and risk of infant death. Weight loss and very low weight gain among women with grades 1 and 2 obesity were associated with high risks of infant mortality. However, even when gestational weight gain in women with obesity was optimized, the predicted risk of infant death remained higher than that of normal-weight women. Interventions aimed at substantially reducing preconception weight among women with obesity and avoiding very low or very high gestational weight gain may reduce risk of infant death. © 2015 The Obesity Society.

Early postnatal weight gain as a predictor for the development of retinopathy of prematurity.

Science.gov (United States)

Biniwale, Manoj; Weiner, Angela; Sardesai, Smeeta; Cayabyab, Rowena; Barton, Lorayne; Ramanathan, Rangasamy

2017-10-01

The objective of this study is to validate the reliability of early postnatal weight gain as an accurate predictor of type 1 retinopathy of prematurity (ROP) requiring treatment in a large predominantly Hispanic US cohort with the use of an online tool called WINROP (weight, neonatal retinopathy of prematurity (IGF-1), neonatal retinopathy of prematurity). Retrospective cohort study consisted of preterm infants <32 weeks gestation and birth weight <1500 g. Weekly weights to 36 weeks post-menstrual age or discharge if earlier were entered into the WINROP tool. This tool generated alarm and risk indicator for developing ROP. The infants with type 1 ROP requiring treatment as well as all stages of ROP were compared with the alarms and risks generated by WINROP tool. A total of 492 infants were entered into the WINROP tool. The infants who developed type 1 ROP requiring treatment, the WINROP tool detected 80/89 (90%) at less than 32 weeks gestation. Nine infants developed type 1 ROP were classified as low risk and did not alarm. Postnatal weight gain alone, in predominantly Hispanic US population, predicted type 1 ROP requiring treatment before 32 weeks of gestation in infants with a sensitivity of 90%. The tool appeared to identify majority of affected infants much earlier than the scheduled screening.

Energy-efficient relay selection and optimal power allocation for performance-constrained dual-hop variable-gain AF relaying

KAUST Repository

Zafar, Ammar; Radaydeh, Redha Mahmoud Mesleh; Chen, Yunfei; Alouini, Mohamed-Slim

2013-01-01

This paper investigates the energy-efficiency enhancement of a variable-gain dual-hop amplify-and-forward (AF) relay network utilizing selective relaying. The objective is to minimize the total consumed power while keeping the end-to-end signal

CONDITIONS FOR CSR MICROBUNCHING GAIN SUPPRESSION

Energy Technology Data Exchange (ETDEWEB)

Tsai, Cheng Ying [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); di Mitri, Simone [Elettra–Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy

2016-05-01

The coherent synchrotron radiation (CSR) of a high brightness electron beam traversing a series of dipoles, such as transport arcs, may result in phase space degradation. On one hand, the CSR can perturb electron transverse motion in dispersive regions along the beamline, causing emittance growth. On the other hand, the CSR effect on the longitudinal beam dynamics could result in microbunching gain enhancement. For transport arcs, several schemes have been proposed* to suppress the CSR-induced emittance growth. Similarly, several scenarios have been introduced** to suppress CSR-induced microbunching gain, which however mostly aim for linac-based machines. In this paper we try to provide sufficient conditions for suppression of CSR-induced microbunching gain along a transport arc, analogous to*. Several example lattices are presented, with the relevant microbunching analyses carried out by our semi-analytical Vlasov solver***. The simulation results show that lattices satisfying the proposed conditions indeed have microbunching gain suppressed. We expect this analysis can shed light on lattice design approach that could suppress the CSR-induced microbunching gain.

Novel T-Z source inverter with high voltage gain and reduced transformer turn ratio

DEFF Research Database (Denmark)

Mostaan, Ali; Sharifi Malfejani, Saeed; Soltani, Mohsen

2015-01-01

Novel voltage source inverter based on the Z source inverter structure is introduced in this paper. In this new inverter, two inductors of the impedance network in conventional Z source inverter are replaced with two transformers or coupled inductors, but unlike the T-Z source inverter that it......'s voltage gain is raised with increasing the transformers turn ratio, the voltage gain in the proposed inverter is raised with lowering the transformer turn ratio. Therefore, transformers with lower turn ratio are required in the proposed inverter in compare with T- Z source inverter that can lead to lower...

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.

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.

How to Assess Product Performance in the Circular Economy? Proposed Requirements for the Design of a Circularity Measurement Framework

OpenAIRE

Saidani , Michael; YANNOU , Bernard; Leroy , Yann; Cluzel , François

2017-01-01

International audience; Assessing product circularity performance is not straightforward. Meanwhile, it gains increasingly importance for businesses and industrial practitioners who are willing to effectively take benefits from circular economy promises. Thus, providing methods and tools to evaluate then enhance product performance—in the light of circular economy—becomes a significant but still barely addressed topic. Following a joint agreement on the need to measure product circularity per...

Effect of Tactile-Kinesthetic Stimulation on Weight Gaining of Preterm Infants

Directory of Open Access Journals (Sweden)

Mahdi Basiry

2009-11-01

Full Text Available Background:The quality of life and standard of health care in a society is measured  by its preterm infants' mortality rate. The popularity and credibility of alternative treatment such as touch therapy may be effective in preterm and low birth weightinfants in order to increase their survival rate.The aim of this study was to determine the effect of touch intervention on the weight gain of preterm infants who were admitted to the Neonatal Intensive Care Unite(NICU. Methods:This study was a randomized controlled trial performed in NICU of  Emamreza hospital,Mashhad,Iran,from July 2007 to November 2007. There were two groups (the control group and the case group and one response variable (weight gain.Infants in the control group received routine nursing care. Infants in the case  group,in addition to the routine care,received stroking/passive limb movement therapy  for three 15 minute sessions per day for a 10 day period.Then weight gaining was compared between the two groups .  Results:The weight gain data was analyzed by SPSS software. Over the 10 day study period, the case group gained significantly more weight compared to the control  group (p(p<0.001(.Conclusion:The data suggest that stroking/passive limb movement can be an efficientand cost effective way of enhancing growth in stable preterm infants .

Opportunistic Fixed Gain Bidirectional Relaying with Outdated CSI

KAUST Repository

Khan, Fahd Ahmed; Tourki, Kamel; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

2015-01-01

In a network with multiple relays, relay selection has been shown as an effective scheme to achieve diversity as well as to improve the overall throughput. This paper studies the impact of using outdated channel state information for relay selection on the performance of a network where two sources communicate with each other via fixed-gain amplify-and-forward relays. For a Rayleigh faded channel, closed-form expressions for the outage probability, moment generating function and symbol error rate are derived. Simulations results are also presented to corroborate the derived analytical results. It is shown that adding relays does not improve the performance if the channel is substantially outdated. Furthermore, relay location is also taken into consideration and it is shown that the performance can be improved by placing the relay closer to the source whose channel is more outdated. © 2015 IEEE.

Opportunistic Fixed Gain Bidirectional Relaying with Outdated CSI

KAUST Repository

Khan, Fahd Ahmed

2015-05-01

In a network with multiple relays, relay selection has been shown as an effective scheme to achieve diversity as well as to improve the overall throughput. This paper studies the impact of using outdated channel state information for relay selection on the performance of a network where two sources communicate with each other via fixed-gain amplify-and-forward relays. For a Rayleigh faded channel, closed-form expressions for the outage probability, moment generating function and symbol error rate are derived. Simulations results are also presented to corroborate the derived analytical results. It is shown that adding relays does not improve the performance if the channel is substantially outdated. Furthermore, relay location is also taken into consideration and it is shown that the performance can be improved by placing the relay closer to the source whose channel is more outdated. © 2015 IEEE.

Analytical study of optimal design and gain parameters of double-slot plasmonic waveguides

International Nuclear Information System (INIS)

Handapangoda, Dayan; Rukhlenko, Ivan D; Premaratne, Malin

2013-01-01

We theoretically analyze guided modes in optically active and passive double-slot plasmonic waveguides. We show that for one of the two different mode symmetries supported by the waveguide, a most productive guiding condition can be realized by adjusting the thicknesses of the layers to optimal values. We also derive approximate analytic expressions to calculate the optimal geometrical parameters of the waveguide. Interestingly, our analysis shows that the propagation losses associated with the inverse mode symmetry of the double-slot waveguide are comparatively low, regardless of the dimensions of the waveguide. We further show that the propagation losses become the smallest in the limiting case of a single-slot (metal–dielectric–metal (MDM)) waveguide. For both double- and single-slot waveguides, we show that the gain required to overcome the losses can be reduced by choosing a dielectric with a low refractive index. We also derive accurate analytical expressions to readily estimate the critical gain and modal gain of the waveguides. (paper)

Effects of monetary reserves and rate of gain on human risky choice under budget constraints.

Science.gov (United States)

Pietras, Cynthia J; Searcy, Gabriel D; Huitema, Brad E; Brandt, Andrew E

2008-07-01

The energy-budget rule is an optimal foraging model that predicts that choice should be risk averse when net gains plus reserves meet energy requirements (positive energy-budget conditions) and risk prone when net gains plus reserves fall below requirements (negative energy-budget conditions). Studies have shown that the energy-budget rule provides a good description of risky choice in humans when choice is studied under economic conditions (i.e., earnings budgets) that simulate positive and negative energy budgets. In previous human studies, earnings budgets were manipulated by varying earnings requirements, but in most nonhuman studies, energy budgets have been manipulated by varying reserves and/or mean rates of reinforcement. The present study therefore investigated choice in humans between certain and variable monetary outcomes when earnings budgets were manipulated by varying monetary reserves and mean rates of monetary gain. Consistent with the energy-budget rule, choice tended to be risk averse under positive-budget conditions and risk neutral or risk prone under negative-budget conditions. Sequential choices were also well described by a dynamic optimization model, especially when expected earnings for optimal choices were high. These results replicate and extend the results of prior experiments in showing that humans' choices are generally consistent with the predictions of the energy-budget rule when studied under conditions analogous to those used in nonhuman energy-budget studies, and that choice patterns tend to maximize reinforcement.

Improving Genetic Gain with Genomic Selection in Autotetraploid Potato

Directory of Open Access Journals (Sweden)

Anthony T. Slater

2016-11-01

Full Text Available Potato ( L. breeders consider a large number of traits during cultivar development and progress in conventional breeding can be slow. There is accumulating evidence that some of these traits, such as yield, are affected by a large number of genes with small individual effects. Recently, significant efforts have been applied to the development of genomic resources to improve potato breeding, culminating in a draft genome sequence and the identification of a large number of single nucleotide polymorphisms (SNPs. The availability of these genome-wide SNPs is a prerequisite for implementing genomic selection for improvement of polygenic traits such as yield. In this review, we investigate opportunities for the application of genomic selection to potato, including novel breeding program designs. We have considered a number of factors that will influence this process, including the autotetraploid and heterozygous genetic nature of potato, the rate of decay of linkage disequilibrium, the number of required markers, the design of a reference population, and trait heritability. Based on estimates of the effective population size derived from a potato breeding program, we have calculated the expected accuracy of genomic selection for four key traits of varying heritability and propose that it will be reasonably accurate. We compared the expected genetic gain from genomic selection with the expected gain from phenotypic and pedigree selection, and found that genetic gain can be substantially improved by using genomic selection.

WGC Based Robust and Gain Scheduling PI Controller Design for Condensing Boilers

Directory of Open Access Journals (Sweden)

Cem Onat

2014-05-01

Full Text Available This paper addresses the water temperature PI control in condensing domestic boilers. The main challenge of this process under the controller design perspective is the fact that the dynamics of condensing boilers are strongly affected by the demanded water flow rate. First, a robust PI controller based on weighted geometrical center method is designed that stabilizes and achieves good performance for closed-loop system for a wide range of the water flow rate. Then, it is shown that if the water flow rate information is used to update the controller gains, through a technique known as gain scheduled control, the performance can be significantly improved. Important characteristics of these PI design approaches are that the resulting parameters are calculated numerically without using any graphical method or iterative optimization process and that it guarantees the stability of the closed-loop. Significantly, simulation results have demonstrated that the proposed tuning techniques can perform better for set point changes and load disturbance than other available methods in the literature.

24 CFR 3280.507 - Comfort heat gain.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Comfort heat gain. 3280.507 Section... gain. Information necessary to calculate the home cooling load shall be provided as specified in this part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss...

Creating sustainable performance.

Science.gov (United States)

Spreitzer, Gretchen; Porath, Christine

2012-01-01

What makes for sustainable individual and organizational performance? Employees who are thriving-not just satisfied and productive but also engaged in creating the future. The authors found that people who fit this description demonstrated 16% better overall performance, 125% less burnout, 32% more commitment to the organization, and 46% more job satisfaction than their peers. Thriving has two components: vitality, or the sense of being alive and excited, and learning, or the growth that comes from gaining knowledge and skills. Some people naturally build vitality and learning into their jobs, but most employees are influenced by their environment. Four mechanisms, none of which requires heroic effort or major resources, create the conditions for thriving: providing decision-making discretion, sharing information about the organization and its strategy, minimizing incivility, and offering performance feedback. Organizations such as Alaska Airlines, Zingerman's, Quicken Loans, and Caiman Consulting have found that helping people grow and remain energized at work is valiant on its own merits-but it can also boost performance in a sustainable way.

Landau damping: the mechanics model and its ultimate entropy gain

International Nuclear Information System (INIS)

Hannay, J H; Kluge, Michel

2011-01-01

Classical mechanics has only been invoked to account for Landau damping in a rather half-hearted way, alongside plasma perturbation theory. In particular this invocation is essential for the study of the saturation, or post-linear (or 'nonlinear') regime of the damping initiated by Dawson and O'Neill. By embracing mechanics wholeheartedly here, with its attendant phase space, one can access results, old and new, cleanly and directly, and with one fewer numerical integration for the post-linear regime. By using a summation technique familiar in semiclassical quantum mechanics (Poisson summation), the one remaining numerical integration can be much improved in accuracy. Also accessible from mechanics is the ultimate entropy gain. Though zero for any finite time (in the absence of coarse graining), the entropy gain is ultimately non-zero (at infinite time the required coarse graining is zero). It is calculated analytically by using the appropriate asymptotics, hitherto not fully exploited.

A Sigma-Delta ADC with Decimation and Gain Control Function for a Bluetooth Receiver in 130 nm Digital CMOS

Directory of Open Access Journals (Sweden)

Koh Jinseok

2006-01-01

Full Text Available We present a discrete-time second-order multibit sigma-delta ADC that filters and decimates by two the input data samples. At the same time it provides gain control function in its input sampling stage. A 4-tap FIR switched capacitor (SC architecture was chosen for antialiasing filtering. The decimation-by-two function is realized using divided-by-two clock signals in the antialiasing filter. Antialiasing, gain control, and sampling functions are merged in the sampling network using SC techniques. This compact architecture allows operating the preceding blocks at twice the ADC's clock frequency, thus improving the noise performance of the wireless receiver channel and relaxing settling requirements of the analog building blocks. The presented approach has been validated and incorporated in a commercial single-chip Bluetooth radio realized in a 1.5 V 130 nm digital CMOS process. The measured antialiasing filtering shows better than 75 dB suppression at the folding frequency band edge. A 67 dB dynamic range was measured with a sampling frequency of 37.5MHz.

Spontaneous indices are inconsistent with arterial baroreflex gain.

Science.gov (United States)

Lipman, Ruth D; Salisbury, Julie K; Taylor, J Andrew

2003-10-01

Spontaneously occurring, parallel fluctuations in arterial pressure and heart period are frequently used as indices of baroreflex function. Despite the convenience of spontaneous indices, their relation to the arterial baroreflex remains unclear. Therefore, in 97 volunteers, we derived 5 proposed indices (sequence method, alpha-index, transfer function, low-frequency transfer function, and impulse response function), compared them with arterial baroreflex gain (by the modified Oxford pharmacologic technique), and examined their relation to carotid distensibility and respiratory sinus arrhythmia. The subjects comprised men and women (n=41) aged 25 to 86 years, 30% of whom had established coronary artery disease. Generally, the indices were correlated with each other (except alpha-index and low-frequency transfer function) and with baroreflex gain. However, the Bland-Altman method demonstrated that the spontaneous indices had limits of agreement as large as the baroreflex gain itself. Even in individuals within the lowest tertile of baroreflex gain for whom baroreflex gain appears to be the most clinically relevant, spontaneous indices failed to relate to baroreflex gain. In fact, for these individuals, there was no correlation between any index and baroreflex gain. Forward stepwise linear regression showed that all spontaneous indices and baroreflex gain were related to respiratory sinus arrhythmia, but only baroreflex gain was related to carotid distensibility. Therefore, these data suggest that spontaneous indices are inadequate estimates of gain and are inconsistent with arterial baroreflex function.

Integration plan required by performance agreement SM 7.2.1

International Nuclear Information System (INIS)

Diediker, L.P.

1997-01-01

Fluor Daniel Hanford, Inc. and its major subcontractors are in agreement that environmental monitoring performed under the Project Hanford Management Contract is to be done in accordance with a single, integrated program. The purpose of this Integration Plan for Environmental Monitoring is to document the policies, systems, and processes being put in place to meet one key objective: manage and integrate a technically competent, multi-media ambient environmental monitoring program, in an efficient, cost effective manner. Fluor Daniel Hanford, Inc. and its major subcontractors also commit to conducting business in a manner consistent with the International Standards Organization 14000 Environmental Management System concepts. Because the integration of sitewide groundwater monitoring activities is managed by the Environmental Restoration Contractor, groundwater monitoring it is outside the scope of this document. Therefore, for the purpose of this Integration Plan for Environmental Monitoring, the Integrated Environmental Monitoring Program is defined as applicable to all environmental media except groundwater. This document provides recommendations on future activities to better integrate the overall environmental monitoring program, with emphasis on the near-field program. In addition, included is the Fluor Daniel Hanford, Inc. team review of the environmental monitoring activities on the Hanford Site, with concurrence of Pacific Northwest National Laboratory and Bechtel Hanford, Inc. (The narrative provided later in the Discussion Section describes the review and consideration given to each topic.) This document was developed to meet the requirements of the Project Hanford Management Contract performance agreement (SM7.2) and the tenets of the U.S. Department of Energy's Effluent and Environmental Monitoring Planning Process. This Plan is prepared for the U.S. Department of Energy, Richland Operations Office, Environmental Assurance, Permits, and Policy Division

Insulin detemir attenuates food intake, body weight gain and fat mass gain in diet-induced obese Sprague-Dawley rats.

Science.gov (United States)

Rojas, J M; Printz, R L; Niswender, K D

2011-07-04

Initiation and intensification of insulin therapy commonly causes weight gain, a barrier to therapy. A contrasting body of evidence indicates that insulin functions as an adiposity negative feedback signal and reduces food intake, weight gain and adiposity via action in the central nervous system. Basal insulin analogs, detemir (Det) and glargine (Glar), have been associated with less hypoglycemia compared with neutral protamine hagedorn insulin, and Det with less weight gain, especially in patients with higher body mass index (BMI). We sought to determine whether insulin therapy per se causes body weight and fat mass gain when delivered via a clinically relevant subcutaneous (SC) route in the absence of hypoglycemia and glycosuria in non-diabetic lean and diet-induced obese rats. Rats were exposed to either a low-fat diet (LFD; 13.5% fat) or high-fat diet (HFD; 60% fat), and received Det (0.5 U kg(-1)), Glar (0.2 U kg(-1)) or vehicle (Veh) SC once daily for 4 weeks. These dosages of insulin were equipotent in rats with respect to blood-glucose concentration and did not induce hypoglycemia. As predicted by current models of energy homeostasis, neither insulin Det nor Glar therapy affected food intake and weight gain in LFD rats. Det treatment significantly attenuated food intake, body weight gain and fat mass gain relative to the Glar and Veh in high-fat fed animals, mirroring observations in humans. That neither insulin group gained excess weight, suggests weight gain with SC basal insulin therapy may not be inevitable. Our data further suggest that Det possesses a unique property to attenuate the development of obesity associated with a HFD.

PV source based high voltage gain current fed converter

Science.gov (United States)

Saha, Soumya; Poddar, Sahityika; Chimonyo, Kudzai B.; Arunkumar, G.; Elangovan, D.

2017-11-01

This work involves designing and simulation of a PV source based high voltage gain, current fed converter. It deals with an isolated DC-DC converter which utilizes boost converter topology. The proposed converter is capable of high voltage gain and above all have very high efficiency levels as proved by the simulation results. The project intends to produce an output of 800 V dc from a 48 V dc input. The simulation results obtained from PSIM application interface were used to analyze the performance of the proposed converter. Transformer used in the circuit steps up the voltage as well as to provide electrical isolation between the low voltage and high voltage side. Since the converter involves high switching frequency of 100 kHz, ultrafast recovery diodes are employed in the circuitry. The major application of the project is for future modeling of solar powered electric hybrid cars.

Shaping performance: do international accreditations and quality management really help?

OpenAIRE

Nigsch, Stefano; Schenker-Wicki, Andrea

2012-01-01

In recent years, international accreditations from private providers have gained importance among business schools all over the world. Higher education managers increasingly see these accreditations as a way of assuring and developing quality in order to comply with international standards, enhance performance, and increase reputation. However, given that an accreditation process requires a great deal of resources and that it might increase bureaucratization and control, international accredi...

Satellite Ocean Color Sensor Design Concepts and Performance Requirements

Science.gov (United States)

McClain, Charles R.; Meister, Gerhard; Monosmith, Bryan

2014-01-01

In late 1978, the National Aeronautics and Space Administration (NASA) launched the Nimbus-7 satellite with the Coastal Zone Color Scanner (CZCS) and several other sensors, all of which provided major advances in Earth remote sensing. The inspiration for the CZCS is usually attributed to an article in Science by Clarke et al. who demonstrated that large changes in open ocean spectral reflectance are correlated to chlorophyll-a concentrations. Chlorophyll-a is the primary photosynthetic pigment in green plants (marine and terrestrial) and is used in estimating primary production, i.e., the amount of carbon fixed into organic matter during photosynthesis. Thus, accurate estimates of global and regional primary production are key to studies of the earth's carbon cycle. Because the investigators used an airborne radiometer, they were able to demonstrate the increased radiance contribution of the atmosphere with altitude that would be a major issue for spaceborne measurements. Since 1978, there has been much progress in satellite ocean color remote sensing such that the technique is well established and is used for climate change science and routine operational environmental monitoring. Also, the science objectives and accompanying methodologies have expanded and evolved through a succession of global missions, e.g., the Ocean Color and Temperature Sensor (OCTS), the Seaviewing Wide Field-of-view Sensor (SeaWiFS), the Moderate Resolution Imaging Spectroradiometer (MODIS), the Medium Resolution Imaging Spectrometer (MERIS), and the Global Imager (GLI). With each advance in science objectives, new and more stringent requirements for sensor capabilities (e.g., spectral coverage) and performance (e.g., signal-to-noise ratio, SNR) are established. The CZCS had four bands for chlorophyll and aerosol corrections. The Ocean Color Imager (OCI) recommended for the NASA Pre-Aerosol, Cloud, and Ocean Ecosystems (PACE) mission includes 5 nanometers hyperspectral coverage from 350 to

Structured, Gain-Scheduled Control of Wind Turbines

DEFF Research Database (Denmark)

Adegas, Fabiano Daher

2013-01-01

Improvements in cost-effectiveness and reliability of wind turbines is a constant in the industry. This requires new knowledge and systematic methods for analyzing and designing the interaction of structural dynamics, aerodynamics, and controllers. This thesis presents novel methods and theoretical....... Robustness and fault-tolerance capabilities are also important properties, which should be considered in the design process. Novel gain-scheduling and robust control methods that adapt to variations in the operational conditions of the wind turbine are proposed under the linear parameter-varying (LPV...... intuitive and physical specifications for vibration control, such as minimum damping and decay rate of aeroelastic modes. Moreover, the number of weighting functions and consequently the order of the final controller is reduced. Inspired by this application, theoretical control developments are presented...

Logistics-production, logistics-marketing and external integration: Their impact on performance

OpenAIRE

Giménez, Cristina; Ventura, Eva

2003-01-01

Highly competitive environments are leading companies to implement Supply Chain Management (SCM) to improve performance and gain a competitive advantage. SCM involves integration, co-ordination and collaboration across organisations and throughout the supply chain. It means that SCM requires internal (intraorganisational) and external (interorganisational) integration. This paper examines the Logistics-Production and Logistics- Marketing interfaces and their relation with the external integra...

Ejector-Enhanced, Pulsed, Pressure-Gain Combustor

Science.gov (United States)

Paxson, Daniel E.; Dougherty, Kevin T.

2009-01-01

An experimental combination of an off-the-shelf valved pulsejet combustor and an aerodynamically optimized ejector has shown promise as a prototype of improved combustors for gas turbine engines. Despite their name, the constant pressure combustors heretofore used in gas turbine engines exhibit typical pressure losses ranging from 4 to 8 percent of the total pressures delivered by upstream compressors. In contrast, the present ejector-enhanced pulsejet combustor exhibits a pressure rise of about 3.5 percent at overall enthalpy and temperature ratios compatible with those of modern turbomachines. The modest pressure rise translates to a comparable increase in overall engine efficiency and, consequently, a comparable decrease in specific fuel consumption. The ejector-enhanced pulsejet combustor may also offer potential for reducing the emission of harmful exhaust compounds by making it practical to employ a low-loss rich-burn/quench/lean-burn sequence. Like all prior concepts for pressure-gain combustion, the present concept involves an approximation of constant-volume combustion, which is inherently unsteady (in this case, more specifically, cyclic). The consequent unsteadiness in combustor exit flow is generally regarded as detrimental to the performance of downstream turbomachinery. Among other adverse effects, this unsteadiness tends to detract from the thermodynamic benefits of pressure gain. Therefore, it is desirable in any intermittent combustion process to minimize unsteadiness in the exhaust path.

Human performance in radiological survey scanning

International Nuclear Information System (INIS)

Brown, W.S.; Abelquist, E.W.

1998-03-01

The probability of detecting residual contamination in the field using portable radiological survey instruments depends not only on the sensitivity of the instrumentation used in scanning, but also on the surveyor's performance. This report provides a basis for taking human performance into account in determining the minimum level of activity detectable by scanning. A theoretical framework was developed (based on signal detection theory) which allows influences on surveyors to be anticipated and understood, and supports a quantitative assessment of performance. The performance of surveyors under controlled yet realistic field conditions was examined to gain insight into the task and to develop means of quantifying performance. Then, their performance was assessed under laboratory conditions to quantify more precisely their ability to make the required discriminations. The information was used to characterize surveyors' performance in the scanning task and to provide a basis for predicting levels of radioactivity that are likely to be detectable under various conditions by surveyors using portable survey instruments

Human performance in radiological survey scanning

Energy Technology Data Exchange (ETDEWEB)

Brown, W.S. [Brookhaven National Lab., Upton, NY (United States); Abelquist, E.W. [Oak Ridge Inst. for Science and Education, TN (United States)

1998-03-01

The probability of detecting residual contamination in the field using portable radiological survey instruments depends not only on the sensitivity of the instrumentation used in scanning, but also on the surveyor`s performance. This report provides a basis for taking human performance into account in determining the minimum level of activity detectable by scanning. A theoretical framework was developed (based on signal detection theory) which allows influences on surveyors to be anticipated and understood, and supports a quantitative assessment of performance. The performance of surveyors under controlled yet realistic field conditions was examined to gain insight into the task and to develop means of quantifying performance. Then, their performance was assessed under laboratory conditions to quantify more precisely their ability to make the required discriminations. The information was used to characterize surveyors` performance in the scanning task and to provide a basis for predicting levels of radioactivity that are likely to be detectable under various conditions by surveyors using portable survey instruments.

Gain investigation of Perylene-Red-doped PMMA for stimulated luminescent solar concentrators.

Science.gov (United States)

Kaysir, Md Rejvi; Fleming, Simon; Argyros, Alexander

2018-04-01

Luminescent solar concentrators (LSCs) utilizing stimulated emission by a seed laser are a promising approach to overcome the limitations of conventional LSCs, with a significant reduction of the photovoltaic material. In our previous work, we demonstrated the principle of a stimulated LSC (s-LSC) and correspondingly developed a model for quantifying the output power of such a system, taking into account different important physical parameters. The model suggested Perylene Red (PR) dye as a potential candidate for s-LSCs. Here, we experimentally investigate the gain of PR-doped polymethyl methacrylate (PMMA) required for s-LSCs using a single pump wavelength (instead of the solar spectrum) as a proof of principle. The results found from the experiment are well matched with the previously developed numerical model except for gain saturation, which occurs at a comparatively small seed laser signal power. To investigate the gain saturation, two approaches were taken: investigating (i) spectral hole burning and (ii) triplet state absorption. Experimental investigation of spectral hole burning with PR dyes showed a small effect on the gain saturation. We developed a general state model considering triplet state absorption of the PR dyes for the second approach. The state model suggests that the PR dyes suffer from significant triplet state absorption loss, which obstructs the normal operation of the PR-based s-LSC system.

Determining required valve performance for discrete control of PTO cylinders for wave energy

DEFF Research Database (Denmark)

Hansen, Rico Hjerm; Andersen, Torben Ole; Pedersen, Henrik C.

2012-01-01

investigates the required valve performance to achieve this energy efficient operation, while meeting basic dynamic requirements. The components making up the total energy loss during shifting is identified by analytically expressing the losses from the governing differential equations. From the analysis...... a framework for evaluating the adequacy of a valve’s response is established, and the analysis shows the results may be normalised for a wider range of systems. Finally, the framework is successfully applied to the Wavestar converter....

Position requirements for space station personnel and linkages to portable microcomputer performance assessment

Science.gov (United States)

Jeanneret, P. R.

1988-01-01

The development and use of a menu of performance tests that can be self-administered on a portable microcomputer are investigated. In order to identify, develop, or otherwise select the relevant human capabilities/attributes to measure and hence include in the performance battery, it is essential that an analysis be conducted of the jobs or functions that will be performed throughout a space shuttle mission. The primary job analysis instrument, the Position Analysis Questionnaire (PAQ), is discussed in detail so the reader will have sufficient background for understanding the application of the instrument to the various work activities included within the scope of the study, and the derivation of the human requirements (abilities/attributes) from the PAQ analyses. The research methodology is described and includes the procedures used for gathering the PAQ data. The results are presented in detail with specific emphasis on identifying critical requirements that can be measured with a portable computerized assessment battery. A discussion of the results is given with implications for future research.

Highly efficient multifunctional metasurface for high-gain lens antenna application

Science.gov (United States)

Hou, Haisheng; Wang, Guangming; Li, Haipeng; Guo, Wenlong; Li, Tangjing

2017-07-01

In this paper, a novel multifunctional metasurface combining linear-to-circular polarization conversion and electromagnetic waves focusing has been proposed and applied to design a high-gain lens antenna working at Ku band. The multifunctional metasurface consists of 15 × 15 unit cells. Each unit cell is composed of four identical metallic layers and three intermediate dielectric layers. Due to well optimization, the multifunctional metasurface can convert the linearly polarized waves generated by the source to circularly polarized waves and focus the waves. By placing a patch antenna operating at 15 GHz at the focal point of the metasurface and setting the focal distance to diameter ratio ( F/ D) to 0.34, we obtain a multifunctional lens antenna. Simulated and measured results coincide well, indicating that the metasurface can convert linearly polarized waves to right-handed circularly polarized waves at 15 GHz with excellent performances in terms of the 3 dB axial ratio bandwidth of 5.3%, realized gain of 16.9 dB and aperture efficiency of 41.2%. Because of the advantages of high gain, competitive efficiency and easy fabrication, the proposed lens antenna has a great potential application in wireless and satellite communication.

High-Current Gain Two-Dimensional MoS 2 -Base Hot-Electron Transistors

KAUST Repository

Torres, Carlos M.

2015-12-09

The vertical transport of nonequilibrium charge carriers through semiconductor heterostructures has led to milestones in electronics with the development of the hot-electron transistor. Recently, significant advances have been made with atomically sharp heterostructures implementing various two-dimensional materials. Although graphene-base hot-electron transistors show great promise for electronic switching at high frequencies, they are limited by their low current gain. Here we show that, by choosing MoS2 and HfO2 for the filter barrier interface and using a noncrystalline semiconductor such as ITO for the collector, we can achieve an unprecedentedly high-current gain (α ∼ 0.95) in our hot-electron transistors operating at room temperature. Furthermore, the current gain can be tuned over 2 orders of magnitude with the collector-base voltage albeit this feature currently presents a drawback in the transistor performance metrics such as poor output resistance and poor intrinsic voltage gain. We anticipate our transistors will pave the way toward the realization of novel flexible 2D material-based high-density, low-energy, and high-frequency hot-carrier electronic applications. © 2015 American Chemical Society.

High-Current Gain Two-Dimensional MoS 2 -Base Hot-Electron Transistors

KAUST Repository

Torres, Carlos M.; Lan, Yann Wen; Zeng, Caifu; Chen, Jyun Hong; Kou, Xufeng; Navabi, Aryan; Tang, Jianshi; Montazeri, Mohammad; Adleman, James R.; Lerner, Mitchell B.; Zhong, Yuan Liang; Li, Lain-Jong; Chen, Chii Dong; Wang, Kang L.

2015-01-01

The vertical transport of nonequilibrium charge carriers through semiconductor heterostructures has led to milestones in electronics with the development of the hot-electron transistor. Recently, significant advances have been made with atomically sharp heterostructures implementing various two-dimensional materials. Although graphene-base hot-electron transistors show great promise for electronic switching at high frequencies, they are limited by their low current gain. Here we show that, by choosing MoS2 and HfO2 for the filter barrier interface and using a noncrystalline semiconductor such as ITO for the collector, we can achieve an unprecedentedly high-current gain (α ∼ 0.95) in our hot-electron transistors operating at room temperature. Furthermore, the current gain can be tuned over 2 orders of magnitude with the collector-base voltage albeit this feature currently presents a drawback in the transistor performance metrics such as poor output resistance and poor intrinsic voltage gain. We anticipate our transistors will pave the way toward the realization of novel flexible 2D material-based high-density, low-energy, and high-frequency hot-carrier electronic applications. © 2015 American Chemical Society.

The cost-effectiveness of CT-guided sacroiliac joint injections: a measure of QALY gained.

Science.gov (United States)

Bydon, Mohamad; Macki, Mohamed; De la Garza-Ramos, Rafael; Youssef, Mina; Gokaslan, Ziya L; Meleka, Sherif; Bydon, Ali

2014-10-01

The purpose of this study is to estimate the total cost and the quality of life years (QALY) gained for computer tomography (CT)-guided sacroiliac joint (SIJ) injections. The cost per QALY gained for the procedure is the primary end-point of this study. In our 1-year prospective institutional study, we gathered 30 patients undergoing CT-guided SIJ injections for degenerative changes at the SIJ space. Patient-reported outcomes included both the US population-based EQ-5D (EuroQol) index score and the EQ-visual analog scale (VAS). The EQ-5D is based on mobility, self-care, usual activities, pain/discomfort, and anxiety depression. Utility expenditures were based on hospital charges at our institution. All 30 patients had one pre-injection physician visit followed by 43 initial injections (13 bilateral). Each patient underwent one CT scan, and three patients required additional plain films. In the 1 year following the injections, 26 physician visits were documented. Five patients required repeat CT-guided injections. Total 1-year cost for all 30 patients was $34 874·00. Mean decrease in EQ-VAS was 0·60 (P  =  0·187). The mean 1-year gain of 0·58 EQ-5D QALY reached statistical significance (P sacroiliac injections was $2004·29. In one of the first cost analyses of CT-guided sacroiliac injections, we found that the procedure improves pain and activities of daily living. The cost per QALY gained by CT-guided sacroiliac injections falls well below the threshold cost of 1 QALY, suggesting that the procedure is strongly cost-effective.

Do Gains in Secondary Teachers’ Content Knowledge Provide an ASSET to Student Learning?

Science.gov (United States)

Hites, Travis

2015-01-01

During the Summer of 2013, a group of East Texas middle and high school science teachers attended the first year of the Astronomy Summer School of East Texas (ASSET), a two-week NASA funded workshop. This workshop focused on providing area teachers with a rigorous two-week experience loaded with interactive content lessons combined with hands-on activities, all relating to the universal laws of astronomy as well as solar system concepts.The effectiveness of this workshop was gauged in part through a series of content surveys given to each participating educator at the beginning and end of the workshop. Similar content surveys were also administered to each teacher's students as pre/post-content surveys in an effort to determine the extent to which teacher gains were transferred into student gains, as well as to judge the effectiveness of the teachers' lessons in conveying these concepts to the students.Overall, students performed best on concepts where teachers exhibited the highest gains in their learning and focused most of their emphasis. A question-by-question analysis, though, suggests that a broad analysis paints an incomplete picture of student learning. We will present an item analysis of student gains by topic along with a comparison of content coverage and teacher gains. Looking beyond these numbers will present results that demonstrate that giving secondary teachers professional development opportunities to increase content knowledge, and tools to present such knowledge to their students, can improve student learning and performance, but is dependent on teacher confidence and level of coverage.This project is supported by the NASA Science Mission Directorate Education and Public Outreach for Earth and Space Science (EPOESS), which is part of the Research Opportunities in Space and Earth Sciences (ROSES), Grant Number NNX12AH11G.

The effect of holiday weight gain on body weight.

Science.gov (United States)

Schoeller, Dale A

2014-07-01

The topic of holiday weight gain has been a frequent subject of the lay media; however, scientific interest has only been recent. Multiple studies in Western societies have reported average weight gains among adults during the period between mid-November and mid-January that were about 0.5 kg. The range in individual weight changes was large, however, and the already overweight and obese gain more weight than those who are healthy weight. When the average gain across the year was also measured, the holiday weight was the major contributor to annual excess weight gain. Efforts patterned to increase awareness to energy balance and body weight have been shown to be successful at reducing such gain. An exception to holiday weight gain being a major contributor to annual excess gain has been children, in whom summer weight gains have been observed to be the major contributor to average excess weight gain. Copyright © 2014 Elsevier Inc. All rights reserved.

New Source Review and coal plant efficiency gains: How new and forthcoming air regulations affect outcomes

International Nuclear Information System (INIS)

Adair, Sarah K.; Hoppock, David C.; Monast, Jonas J.

2014-01-01

Forthcoming carbon dioxide (CO 2 ) regulations for existing power plants in the United States have heightened interest in thermal efficiency gains for coal-fired power plants. Plant modifications to improve thermal efficiency can trigger New Source Review (NSR), a Clean Air Act requirement to adopt of state-of-the-art pollution controls. This article explores whether existing coal plants would likely face additional pollution control requirements if they undertake modifications that trigger NSR. Despite emissions controls that are or will be installed under the Mercury and Air Toxics Standards (MATS) and Clean Air Interstate Rule (CAIR) or its replacement, 80% of coal units (76% of capacity) that are expected to remain in operation are not projected to meet the minimum NSR requirements for at least one pollutant: nitrogen oxides or sulfur dioxide. This is an important consideration for the U.S. Environmental Protection Agency and state policymakers as they determine the extent to which CO 2 regulation will rely on unit-by-unit thermal efficiency gains versus potential flexible compliance strategies such as averaging, trading, energy efficiency, and renewable energy. NSR would likely delay and add cost to thermal efficiency projects at a majority of coal units, including projects undertaken to comply with forthcoming CO 2 regulation. - Highlights: • We explore the status of the U.S. coal-fired fleet relative to New Source Review (NSR) requirements. • Modifications to improve thermal efficiency can trigger NSR. • Thermal efficiency gains may also be an important strategy for forthcoming CO 2 regulation. • 80% Of non-retiring coal-fired units are projected not to meet minimum NSR requirements. • NSR is an important consideration for the design of CO 2 regulations for existing plants

Common display performance requirements for military and commercial aircraft product lines

Science.gov (United States)

Hoener, Steven J.; Behrens, Arthur J.; Flint, John R.; Jacobsen, Alan R.

2001-09-01

Obtaining high quality Active Matrix Liquid Crystal (AMLCD) glass to meet the needs of the commercial and military aerospace business is a major challenge, at best. With the demise of all domestic sources of AMLCD substrate glass, the industry is now focused on overseas sources, which are primarily producing glass for consumer electronics. Previous experience with ruggedizing commercial glass leads to the expectation that the aerospace industry can leverage off the commercial market. The problem remains, while the commercial industry is continually changing and improving its products, the commercial and military aerospace industries require stable and affordable supplies of AMLCD glass for upwards of 20 years to support production and maintenance operations. The Boeing Engineering and Supplier Management Process Councils have chartered a group of displays experts from multiple aircraft product divisions within the Boeing Company, the Displays Process Action Team (DPAT), to address this situation from an overall corporate perspective. The DPAT has formulated a set of Common Displays Performance Requirements for use across the corporate line of commercial and military aircraft products. Though focused on the AMLCD problem, the proposed common requirements are largely independent of display technology. This paper describes the strategy being pursued within the Boeing Company to address the AMLCD supply problem and details the proposed implementation process, centered on common requirements for both commercial and military aircraft displays. Highlighted in this paper are proposed common, or standard, display sizes and the other major requirements established by the DPAT, along with the rationale for these requirements.

Tuning and performance evaluation of PID controller for superheater steam temperature control of 200 MW boiler using gain phase assignment algorithm

Science.gov (United States)

Begum, A. Yasmine; Gireesh, N.

2018-04-01

In superheater, steam temperature is controlled in a cascade control loop. The cascade control loop consists of PI and PID controllers. To improve the superheater steam temperature control the controller's gains in a cascade control loop has to be tuned efficiently. The mathematical model of the superheater is derived by sets of nonlinear partial differential equations. The tuning methods taken for study here are designed for delay plus first order transfer function model. Hence from the dynamical model of the superheater, a FOPTD model is derived using frequency response method. Then by using Chien-Hrones-Reswick Tuning Algorithm and Gain-Phase Assignment Algorithm optimum controller gains has been found out based on the least value of integral time weighted absolute error.

Personality type influence the gestational weight gain.

Science.gov (United States)

Franik, Grzegorz; Lipka, Nela; Kopyto, Katarzyna; Kopocińska, Joanna; Owczarek, Aleksander; Sikora, Jerzy; Madej, Paweł; Chudek, Jerzy; Olszanecka-Glinianowicz, Magdalena

2017-08-01

Pregnancy is frequently followed by the development of obesity. Aside from psychological factors, hormonal changes influence weight gain in pregnant women. We attempted to assess the potential association between personality type and the extent of gestational weight gain. The study group involved 773 women after term delivery (age 26.3 ± 3.9 years, body mass before pregnancy 61.2 ± 11.1 kg). Weight gain during pregnancy was calculated by using self-reported body mass prior to and during the 38th week of pregnancy. Personality type was assessed using the Polish version of the Framingham Type A Behavior Patterns Questionnaire (adapted by Juczynski). Two hundred forty-six (31.8%) study subjects represented type A personalities, 272 (35.2%) type B and 255 (33.0%) an indirect type. Gestational weight gain was related to the behavior patterns questionnaire score and age. In women gain was higher than in women with type B behavior of the same age. In women >30, the gestational weight gain was larger for type B personalities. Type A personality and increased urgency in younger pregnant women increases the risk of developing obesity during pregnancy in women below 30 years old. A higher level of competitiveness demonstrates a risk factor of excessive weight gain during pregnancy regardless of age.

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.

The association of students requiring remediation in the internal medicine clerkship with poor performance during internship.

Science.gov (United States)

Hemann, Brian A; Durning, Steven J; Kelly, William F; Dong, Ting; Pangaro, Louis N; Hemmer, Paul A

2015-04-01

To determine whether the Uniformed Services University (USU) system of workplace performance assessment for students in the internal medicine clerkship at the USU continues to be a sensitive predictor of subsequent poor performance during internship, when compared with assessments in other USU third year clerkships. Utilizing Program Director survey results from 2007 through 2011 and U.S. Medical Licensing Examination (USMLE) Step 3 examination results as the outcomes of interest, we compared performance during internship for students who had less than passing performance in the internal medicine clerkship and required remediation, against students whose performance in the internal medicine clerkship was successful. We further analyzed internship ratings for students who received less than passing grades during the same time period on other third year clerkships such as general surgery, pediatrics, obstetrics and gynecology, family medicine, and psychiatry to evaluate whether poor performance on other individual clerkships were associated with future poor performance at the internship level. Results for this recent cohort of graduates were compared with previously published findings. The overall survey response rate for this 5 year cohort was 81% (689/853). Students who received a less than passing grade in the internal medicine clerkship and required further remediation were 4.5 times more likely to be given poor ratings in the domain of medical expertise and 18.7 times more likely to demonstrate poor professionalism during internship. Further, students requiring internal medicine remediation were 8.5 times more likely to fail USMLE Step 3. No other individual clerkship showed any statistically significant associations with performance at the intern level. On the other hand, 40% of students who successfully remediated and did graduate were not identified during internship as having poor performance. Unsuccessful clinical performance which requires remediation in

IQ Gains in Argentina between 1964 and 1998

Science.gov (United States)

Flynn, James R.; Rossi-Case, Lilia

2012-01-01

The literature on IQ gains in Latin America is sparse. We estimate gains on Raven's Progressive Matrices in the city of La Plata (Argentina) between 1964 and 1998. The gains are robust at the top of the curve as well as at the bottom. Therefore, they are contrary to the hypothesis that nutrition played a major role in recent Argentine IQ gains.…

Virtual machine performance benchmarking.

Science.gov (United States)

Langer, Steve G; French, Todd

2011-10-01

The attractions of virtual computing are many: reduced costs, reduced resources and simplified maintenance. Any one of these would be compelling for a medical imaging professional attempting to support a complex practice on limited resources in an era of ever tightened reimbursement. In particular, the ability to run multiple operating systems optimized for different tasks (computational image processing on Linux versus office tasks on Microsoft operating systems) on a single physical machine is compelling. However, there are also potential drawbacks. High performance requirements need to be carefully considered if they are to be executed in an environment where the running software has to execute through multiple layers of device drivers before reaching the real disk or network interface. Our lab has attempted to gain insight into the impact of virtualization on performance by benchmarking the following metrics on both physical and virtual platforms: local memory and disk bandwidth, network bandwidth, and integer and floating point performance. The virtual performance metrics are compared to baseline performance on "bare metal." The results are complex, and indeed somewhat surprising.

The performance of neutron scattering spectrometers at a long-pulse spallation source

International Nuclear Information System (INIS)

Pynn, R.

1997-01-01

In this document the author considers the performance of a long pulse spallation source for those neutron scattering experiments that are usually performed with a monochromatic beam at a continuous wave (CW) source such as a nuclear reactor. The first conclusion drawn is that comparison of the performance of neutron scattering spectrometers at CW and pulsed sources is simpler for long-pulsed sources than it is for the short-pulse variety. Even though detailed instrument design and assessment will require Monte Carlo simulations (which have already been performed at Los Alamos for SANS and reflectometry), simple arguments are sufficient to assess the approximate performance of spectrometers at an LPSS and to support the contention that a 1 MW long-pulse source can provide attractive performance, especially for instrumentation designed for soft-condensed-matter science. Because coupled moderators can be exploited at such a source, its time average cold flux is equivalent to that of a research reactor with a power of about 15 MW, so only a factor of 4 gain from source pulsing is necessary to obtain performance that is comparable with the ILL. In favorable cases, the gain from pulsing can be even more than this, approaching the limit set by the peak flux, giving about 4 times the performance of the ILL. Because of its low duty factor, an LPSS provides the greatest performance gains for relatively low resolution experiments with cold neutrons. It should thus be considered complementary to short pulse sources which are most effective for high resolution experiments using thermal or epithermal neutrons

COMPETENCY, ENTREPRENEUR CHARACTERISTIC AND BUSINESS PERFORMANCE: STUDY OF THE PEMPEK BUSINESS IN PALEMBANG

Directory of Open Access Journals (Sweden)

Fransiska Soejono

2015-01-01

Full Text Available The purpose of this study was to examine empirically the effects of entrepreneurial compe-tencies and characteristics on business performance. Previous studies found that competencies and entrepreneurial characteristics significantly influenced business performance. A quantita-tive method was used and 122 respondents were involved as the sample in this study, who were pempek business owners in Palembang, South Sumatra. The results indicated an effect from entrepreneurial competencies on business performance. It was also found that the entrepre-neurs’ characteristics (owners’ ages significantly affected the businesses’ performance. This implication requires some sort of course or program for the entrepreneurs to improve their competence to direct the owners to gain better business performance. The growing age of the business owners requires equal insights to ensure age does not stop the owners from improving their business’ performance.

Loss restlessness and gain calmness: durable effects of losses and gains on choice switching.

Science.gov (United States)

Yechiam, Eldad; Zahavi, Gal; Arditi, Eli

2015-08-01

While the traditional conceptualization of the effect of losses focuses on bias in the subjective weight of losses compared with respective gains, some accounts suggest more global task-related effects of losses. Based on a recent attentional theory, we predicted a positive after-effect of losses on choice switching in later tasks. In two experimental studies, we found increased choice switching rates in tasks with losses compared to tasks with no losses. Additionally, this heightened shifting behavior was maintained in subsequent tasks that do not include losses, a phenomenon we refer to as "loss restlessness." Conversely, gains were found to have an opposite "calming" effect on choice switching. Surprisingly, the loss restlessness phenomenon was observed following an all-losses payoff regime but not after a task with symmetric mixed gains and losses. This suggests that the unresolved mental account following an all-losses regime increases search behavior. Potential implications to macro level phenomena, such as the leverage effect, are discussed.

Effect of DM Actuator Errors on the WFIRST/AFTA Coronagraph Contrast Performance

Science.gov (United States)

Sidick, Erkin; Shi, Fang

2015-01-01

The WFIRST/AFTA 2.4 m space telescope currently under study includes a stellar coronagraph for the imaging and the spectral characterization of extrasolar planets. The coronagraph employs two sequential deformable mirrors (DMs) to compensate for phase and amplitude errors in creating dark holes. DMs are critical elements in high contrast coronagraphs, requiring precision and stability measured in picometers to enable detection of Earth-like exoplanets. Working with a low-order wavefront-sensor the DM that is conjugate to a pupil can also be used to correct low-order wavefront drift during a scientific observation. However, not all actuators in a DM have the same gain. When using such a DM in low-order wavefront sensing and control subsystem, the actuator gain errors introduce high-spatial frequency errors to the DM surface and thus worsen the contrast performance of the coronagraph. We have investigated the effects of actuator gain errors and the actuator command digitization errors on the contrast performance of the coronagraph through modeling and simulations, and will present our results in this paper.

Quantifying the impact on navigation performance in visually impaired: Auditory information loss versus information gain enabled through electronic travel aids.

Directory of Open Access Journals (Sweden)

Alex Kreilinger

Full Text Available This study's purpose was to analyze and quantify the impact of auditory information loss versus information gain provided by electronic travel aids (ETAs on navigation performance in people with low vision. Navigation performance of ten subjects (age: 54.9±11.2 years with visual acuities >1.0 LogMAR was assessed via the Graz Mobility Test (GMT. Subjects passed through a maze in three different modalities: 'Normal' with visual and auditory information available, 'Auditory Information Loss' with artificially reduced hearing (leaving only visual information, and 'ETA' with a vibrating ETA based on ultrasonic waves, thereby facilitating visual, auditory, and tactile information. Main performance measures comprised passage time and number of contacts. Additionally, head tracking was used to relate head movements to motion direction. When comparing 'Auditory Information Loss' to 'Normal', subjects needed significantly more time (p<0.001, made more contacts (p<0.001, had higher relative viewing angles (p = 0.002, and a higher percentage of orientation losses (p = 0.011. The only significant difference when comparing 'ETA' to 'Normal' was a reduced number of contacts (p<0.001. Our study provides objective, quantifiable measures of the impact of reduced hearing on the navigation performance in low vision subjects. Significant effects of 'Auditory Information Loss' were found for all measures; for example, passage time increased by 17.4%. These findings show that low vision subjects rely on auditory information for navigation. In contrast, the impact of the ETA was not significant but further analysis of head movements revealed two different coping strategies: half of the subjects used the ETA to increase speed, whereas the other half aimed at avoiding contacts.

The influence of loss and gain of body mass on ovarian activity in ...

African Journals Online (AJOL)

Ovarian activity was studied in 36 dry, Bos taurus cows fed to achieve different rates of body mass loss and gain in a 2 x 2 factorial experiment. Cows were fed hay to supply either 70% (Treatments 1, 2) or 40% (Treatments. 3,4) of their ME requirements for maintenance until they became anoestrus. Following a 90-day ...

Changes in working conditions and major weight gain among normal- and overweight midlife employees.

Science.gov (United States)

Niskanen, Riikka; Holstila, Ansku; Rahkonen, Ossi; Lallukka, Tea

2017-11-01

Objectives We aimed to examine the association between changes in psychosocial working conditions and major weight gain among midlife women and men. Furthermore, we examined the associations separately among normal- and overweight participants. Methods We used survey data among employees of the City of Helsinki, Finland, from 2000-2002 (phase 1, N=8960), 2007 (phase 2, N=7332), and 2012 (phase 3, N=6814), with a final study sample of 4369 participants. We examined changes in job strain, job demands, and job control from phase 1 to 2. We defined major weight gain as ≥10% weight gain between phases 1 and 3 based on self-reported weight (kg). We performed logistic regression analysis adjusting for baseline age, marital status, and occupational class, stratifying by gender and by baseline body mass index. Results Job demands among both genders and job strain among women was associated with major weight gain. Furthermore, increased job demands [odds ratio (OR) 1.52, 95% CI 1.05-2.20] or increased job strain (OR 1.53, 95% CI 1.11-2.11) was associated with major weight gain among overweight women. Normal-weight men reporting decreased job demands (OR 4.11, 95% CI 1.48-11.40) and overweight men reporting increasing job demands (OR 2.93, 95% CI 1.26-6.82) exhibited higher odds of major weight gain. Conclusions Associations between working conditions and weight gain appeared primarily weak. Our study suggests that overweight individuals might be at a higher risk of weight gain when facing psychosocial strain in the workplace.

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.

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

A digital gain stabilizer for large volume organic scintillation detectors

International Nuclear Information System (INIS)

Braunsfurth, J.; Geske, K.

1976-01-01

A digital gain stabilizer is described, optimized for use with photomultipliers mounted on large volume organic scintillators, or other radiation detectors, which exhibit no prominent peaks in their amplitude spectra. As applications of this kind usually involve many phototubes or detectors, circuit simplicity, production reproduceability, and the possibility of computer controlled operation were major design criteria. Two versions were built, the first one using standard TTL-SSI and MSI circuitry, the second one - to reduce power requirements - using a mixture of TTL- and CMOS-LSI circuits. (Auth.)

77 FR 11995 - Passenger Vessel Operator Financial Responsibility Requirements for Non-Performance of...

Science.gov (United States)

2012-02-28

... Vessel Operator Financial Responsibility Requirements for Non-Performance of Transportation AGENCY..., 2011, the Commission issued its Notice of Proposed Rulemaking (NPRM) to update its financial... cost of financial responsibility coverage because of the use of alternative coverage options. However...

Experience gained in enhancing operational safety at ComEd`s nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Elias, D [Commonwealth Edison Co. (United States)

1997-09-01

The following aspects of experience gained in enhancing operational safety at Comed`s nuclear power plants are discussed: nuclear safety policy; centralization/decentralization; typical nuclear operating organization; safety review boards; human performance enhancement; elements of effective nuclear oversight.

Measured stimulated Raman gain in methane

International Nuclear Information System (INIS)

Lopert, R.B.

1983-01-01

This report is about the stimulated Raman effect in methane due to the nu 1 vibration. For various gas pressures between 150 torr and 30 atm, the Raman lineshape function was both experimentally measured and synthesized using a computer model. The stimulated Raman gain was measured by sending a pump laser beam provided by an argon-ion laser and a weak probe beam provided by a tunable dye laser through a cell of methane gas. The stimulated Raman effect caused some of the energy from the pump beam to be transferred to the probe beam. The intensity of the pump beam was low so the gain of the probe beam was on the order of parts per million. A two detector arrangement and a differential amplifier system that had a feedback loop to balance the detectors was constructed to measure the small gains. A detailed description of this detection system that was able to measure gains as small as 0.2 parts per million is provided

Prestimulus neural oscillations inhibit visual perception via modulation of response gain.

Science.gov (United States)

Chaumon, Maximilien; Busch, Niko A

2014-11-01

The ongoing state of the brain radically affects how it processes sensory information. How does this ongoing brain activity interact with the processing of external stimuli? Spontaneous oscillations in the alpha range are thought to inhibit sensory processing, but little is known about the psychophysical mechanisms of this inhibition. We recorded ongoing brain activity with EEG while human observers performed a visual detection task with stimuli of different contrast intensities. To move beyond qualitative description, we formally compared psychometric functions obtained under different levels of ongoing alpha power and evaluated the inhibitory effect of ongoing alpha oscillations in terms of contrast or response gain models. This procedure opens the way to understanding the actual functional mechanisms by which ongoing brain activity affects visual performance. We found that strong prestimulus occipital alpha oscillations-but not more anterior mu oscillations-reduce performance most strongly for stimuli of the highest intensities tested. This inhibitory effect is best explained by a divisive reduction of response gain. Ongoing occipital alpha oscillations thus reflect changes in the visual system's input/output transformation that are independent of the sensory input to the system. They selectively scale the system's response, rather than change its sensitivity to sensory information.

Performance Gains of Propellant Management Devices for Liquid Hydrogen Depots

Science.gov (United States)

Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

2013-01-01

This paper presents background, experimental design, and preliminary experimental results for the liquid hydrogen bubble point tests conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to investigate the parameters that affect liquid acquisition device (LAD) performance in a liquid hydrogen (LH2) propellant tank, to mitigate risk in the final design of the LAD for the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission, and to provide insight into optimal LAD operation for future LH2 depots. Preliminary test results show an increase in performance and screen retention over the low reference LH2 bubble point value for a 325 2300 screen in three separate ways, thus improving fundamental LH2 LAD performance. By using a finer mesh screen, operating at a colder liquid temperature, and pressurizing with a noncondensible pressurant gas, a significant increase in margin is achieved in bubble point pressure for LH2 screen channel LADs.

Association between gestational weight gain and perinatal outcomes in women with chronic hypertension.

Science.gov (United States)

Yee, Lynn M; Caughey, Aaron B; Cheng, Yvonne W

2017-09-01

Gestational weight gain above or below the 2009 National Academy of Medicine guidelines has been associated with adverse maternal and neonatal outcomes. Although it has been well established that excess gestational weight gain is associated with the development of gestational hypertension and preeclampsia, the relationship between gestational weight gain and adverse perinatal outcomes among women with pregestational (chronic) hypertension is less clear. The objective of this study was to examine the relationship between gestational weight gain above and below National Academy of Medicine guidelines and perinatal outcomes in a large, population-based cohort of women with chronic hypertension. This is a population-based retrospective cohort study of women with chronic hypertension who had term, singleton, vertex births in the United States from 2012 through 2014. Prepregnancy body mass index was calculated using self-reported prepregnancy weight and height. Women were categorized into 4 groups based on gestational weight gain and prepregnancy body mass index: (1) weight gain less than, (2) weight gain within, (3) weight gain 1-19 lb in excess of, and (4) weight gain ≥20 lb in excess of the National Academy of Medicine guidelines. The χ 2 tests and multivariable logistic regression analysis were used for statistical comparisons. Stratified analyses by body mass index category were additionally performed. In this large birth cohort, 101,259 women met criteria for inclusion. Compared to hypertensive women who had gestational weight gain within guidelines, hypertensive women with weight gain ≥20 lb over National Academy of Medicine guidelines were more likely to have eclampsia (adjusted odds ratio, 1.93; 95% confidence interval, 1.54-2.42) and cesarean delivery (adjusted odds ratio, 1.60; 95% confidence interval, 1.50-1.70). Excess weight gain ≥20 lb over National Academy of Medicine guidelines was also associated with increased odds of 5-minute Apgar gain 1-19 lb

Commercially-driven human interplanetary propulsion systems: Rationale, concept, technology, and performance requirements

International Nuclear Information System (INIS)

Williams, C.H.; Borowski, S.K.

1996-01-01

Previous studies of human interplanetary missions are largely characterized by long trip times, limited performance capabilities, and enormous costs. Until these missions become dramatically more open-quote open-quote commercial-friendly close-quote close-quote, their funding source and rationale will be restricted to national governments and their political/scientific interests respectively. A rationale is discussed for human interplanetary space exploration predicated on the private sector. Space propulsion system requirements are identified for interplanetary transfer times of no more than a few weeks/months to and between the major outer planets. Nuclear fusion is identified as the minimum requisite space propulsion technology. A conceptual design is described and evolutionary catalyzed-DD to DHe 3 fuel cycles are proposed. Magnetic nozzles for direct thrust generation and quantifying the operational aspects of the energy exchange mechanisms between high energy reaction products and neutral propellants are identified as two of the many key supporting technologies essential to satisfying system performance requirements. Government support of focused, breakthrough technologies is recommended at funding levels appropriate to other ongoing federal research. copyright 1996 American Institute of Physics

Growing an emerging energy workforce: forecasting labour demand and gaining access to emerging energy skills

International Nuclear Information System (INIS)

Thomsen, V.

2006-01-01

This paper discusses the needs of emerging energies sector in terms of growing an emerging energy workforce, forecasting labour demands and gaining access to emerging energy skills. It will require industrial renewal and innovation and not just selling our resources. It will also require educating ourselves to utilise our own finished products. Conservation is a key element in a sustainable energy future. finally, a market for renewable energy has been established in Canada

40 CFR 80.815 - What are the gasoline toxics performance requirements for refiners and importers?

Science.gov (United States)

2010-07-01

... toxics requirements of this subpart apply separately for each of the following types of gasoline produced...) The gasoline toxics performance requirements of this subpart apply to gasoline produced at a refinery... not apply to gasoline produced by a refinery approved under § 80.1334, pursuant to § 80.1334(c). (2...

Working-memory training in younger and older adults: Training gains, transfer, and maintenance

Directory of Open Access Journals (Sweden)

Yvonne eBrehmer

2012-03-01

Full Text Available Working memory (WM, a key determinant of many higher-order cognitive functions, declines in old age. Current research attempts to develop process-specific WM training procedures, which may lead to general cognitive improvement. Adaptivity of the training as well as the comparison of training gains to performance changes of an active control group are key factors in evaluating the effectiveness of a specific training program. In the present study, 55 younger adults (20-30 years of age and 45 older adults (60-70 years of age received five weeks of computerized training on various spatial and verbal WM tasks. Half of the sample received adaptive training (i.e., individually adjusted task difficulty, whereas the other half worked on the same task material but on a low task difficulty level (active controls. Performance was assessed using criterion, near-transfer, and far-transfer tasks before training, after 5 weeks of intervention, as well as after a 3-month follow-up interval. Results indicate that (a adaptive training generally led to larger training gains than low-level practice, (b training and transfer gains were somewhat greater for younger than for older adults in some tasks, but comparable across age groups in other tasks, (c far transfer was observed to a test on sustained attention and for a self-rating scale on cognitive functioning in daily life for both young and old, and (d training gains and transfer effects were maintained across the 3-month follow-up interval across age.

Ricardian Productivity Differences and the Gains from Trade

OpenAIRE

Andrei A. Levchenko; Jing Zhang

2013-01-01

This paper evaluates the role of sectoral heterogeneity in determining the gains from trade. We first show analytically that in the presence of sectoral Ricardian comparative advantage, a one- sector sufficient statistic formula that uses total trade volumes as a share of total absorption systematically understates the true gains from trade. Greater relative sectoral productivity differences lead to larger disparities between the gains implied by the one-sector formula and the true gains. Usi...

Active Microwave Metamaterials Incorporating Ideal Gain Devices

Directory of Open Access Journals (Sweden)

Hao Xin

2010-12-01

Full Text Available Incorporation of active devices/media such as transistors for microwave and gain media for optics may be very attractive for enabling desired low loss and broadband metamaterials. Such metamaterials can even have gain which may very well lead to new and exciting physical phenomena. We investigate microwave composite right/left-handed transmission lines (CRLH-TL incorporating ideal gain devices such as constant negative resistance. With realistic lumped element values, we have shown that the negative phase constant of this kind of transmission lines is maintained (i.e., left-handedness kept while gain can be obtained (negative attenuation constant of transmission line simultaneously. Possible implementation and challenging issues of the proposed active CRLH-TL are also discussed.

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.

Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use.

Science.gov (United States)

Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R

2013-01-01

Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior.

Conflict Resolution for Product Performance Requirements Based on Propagation Analysis in the Extension Theory

Directory of Open Access Journals (Sweden)

Yanwei Zhao

2014-01-01

Full Text Available Traditional product data mining methods are mainly focused on the static data. Performance requirements are generally met as possible by finding some cases and changing their structures. However, when one is satisfied with the structures changed, the other effects are not taken into account by analyzing the correlations; that is, design conflicts are not identified and resolved. An approach to resolving the conflict problems is proposed based on propagation analysis in Extension Theory. Firstly, the extension distance is improved to better fit evaluating the similarity among cases, then, a case retrieval method is developed. Secondly, the transformations that can be made on selected cases are formulated by understanding the conflict natures in the different performance requirements, which leads to the extension transformation strategy development for coordinating conflicts using propagation analysis. Thirdly, the effects and levels of propagation are determined by analyzing the performance values before and after the transformations, thus the co-existing conflict coordination strategy of multiple performances is developed. The method has been implemented in a working prototype system for supporting decision-making. And it has been demonstrated the feasible and effective through resolving the conflicts of noise, exhaust, weight and intake pressure for the screw air compressor performance design.

Monitoring of performance management using Quality Assurance Indicators and ISO requirement

Directory of Open Access Journals (Sweden)

Dargahi H

2007-06-01

Full Text Available Background: Quality assurance is a prevention-oriented system that can be used to improve the quality of care, increase productivity and monitor the performance management in clinical laboratories. ISO 9001: 2000 requirements are a collection of management and technical systems designed to implement quality assurance and monitor performance management in organizations. Methods: A checklist was prepared to monitor the preanalytical, analytical and postanalytical stages of laboratory performance management in 16 areas and all laboratory activities in 14 of the clinical laboratories of the Tehran University of Medical Sciences (TUMS hospitals. Collected data were stored and statistically analyzed using SPSS software. Results: The best performance, in which 77.73% of quality assurance indicators were observed, was found in Sina Hospital. However, only 57.56% of these indicators were fulfilled at Farabi Hospital, with the lowest-level performance among the clinical laboratories of TUMS hospitals. The highest level of compliance with quality assurance indicators was in the hematology departments and for facility demands in management areas. Overall, quality assurance indicators were appropriately followed in only 7% of the clinical laboratories. Conclusion: The average quality assurance observation rate in the clinical laboratories studied was 67.22%, which is insufficient and must be remedied with stricter enforcement of the ISO 9001: 2000 regulations.

Nurses' perception of the strategies to gaining professional power: A qualitative study.

Science.gov (United States)

Sepasi, Rana Rezai; Borhani, Fariba; Abbaszadeh, Abbas

2017-07-01

Power in nursing is a broad concept that has a determining effect on the achievement of professional goals. Gaining power is essential for promoting the roles of nurses, improving their professional image and the consistent improvement of healthcare systems. This study was conducted to identify and clarify strategies for gaining power in the nursing profession through the experiences of Iranian nurses. The present qualitative grounded theory study was conducted on fifteen participants selected through purposive sampling. Data were collected through individual, in-depth, semi-structured interviews. The data obtained were analyzed using the guidelines provided by Corbin and Strauss, (2008 edition). This study was carried out in Qazvin city of Iran and lasted fourteen months (2015-2016). The analysis of the data were classified under the main theme of gaining human-professional power based on individual and organizational capacities, divided into four main categories, including respecting human values and ethical principles (with two subcategories, keeping the human symbols of power and commitment to moral obligations of power), promoting professional interactions (with two subcategories, paying attention to intraprofessional communication and paying attention to interprofessional communication), attempting professional endurance (with two subcategories, raising self-confidence and having professional commitment), and valuing potential capacities (with two subcategories, regard for individual capacities and regard for organizational capacities). The findings obtained suggest that success in gaining power in nursing, requires a cumulative focus on human, ethical, professional, individual and organizational capacities.

High-performance workplace practices in nursing homes: an economic perspective.

Science.gov (United States)

Bishop, Christine E

2014-02-01

To develop implications for research, practice and policy, selected economics and human resources management research literature was reviewed to compare and contrast nursing home culture change work practices with high-performance human resource management systems in other industries. The organization of nursing home work under culture change has much in common with high-performance work systems, which are characterized by increased autonomy for front-line workers, self-managed teams, flattened supervisory hierarchy, and the aspiration that workers use specific knowledge gained on the job to enhance quality and customization. However, successful high-performance work systems also entail intensive recruitment, screening, and on-going training of workers, and compensation that supports selective hiring and worker commitment; these features are not usual in the nursing home sector. Thus despite many parallels with high-performance work systems, culture change work systems are missing essential elements: those that require higher compensation. If purchasers, including public payers, were willing to pay for customized, resident-centered care, productivity gains could be shared with workers, and the nursing home sector could move from a low-road to a high-road employment system.

Nine weeks of supplementation with a multi-nutrient product augments gains in lean mass, strength, and muscular performance in resistance trained men

Directory of Open Access Journals (Sweden)

Lemieux Robert

2010-12-01

Full Text Available Abstract Background The purpose of this study was to compare the effects of supplementation with Gaspari Nutrition's SOmaxP Maximum Performance™ (SOmaxP versus a comparator product (CP containing an equal amount of creatine (4 g, carbohydrate (39 g maltodextrin, and protein (7 g whey protein hydrolysate on muscular strength, muscular endurance, and body composition during nine weeks of intense resistance training. Methods Using a prospective, randomized, double-blind design, 20 healthy men (mean ± SD age, height, weight, % body fat: 22.9 ± 2.6 y, 178.4 ± 5.7 cm, 80.5 ± 6.6 kg, 16.6 ± 4.0% were matched for age, body weight, resistance training history, bench press strength, bench press endurance, and percent body fat and then randomly assigned via the ABBA procedure to ingest 1/2 scoop (dissolved in 15 oz water of SOmaxP or CP prior to, and another 1/2 scoop (dissolved in 15 oz water during resistance exercise. Body composition (DEXA, muscular performance (1-RM bench press and repetitions to failure [RTF: 3 sets × baseline body weight, 60-sec rest between sets], and clinical blood chemistries were measured at baseline and after nine weeks of supplementation and training. Subjects were required to maintain their normal dietary habits and follow a specific, progressive overload resistance training program (4-days/wk, upper body/lower body split during the study. An intent-to-treat approach was used and data were analyzed via ANCOVA using baseline values as the covariate. Statistical significance was set a priori at p ≤ 0.05. Results When adjusted for initial differences, significant between group post-test means were noted in: 1-RM bench press (SOmaxP: 133.3 ± 1.3 kg [19.8% increase] vs. CP: 128.5 ± 1.3 kg [15.3% increase]; p Conclusions These data indicate that compared to CP, SOmaxP administration augments and increases gains in lean mass, bench press strength, and muscular performance during nine weeks of intense resistance training

ACCOUNTING FOR MARKETING: MARKETING PERFORMANCE THROUGH FINANCIAL RESULTS

Directory of Open Access Journals (Sweden)

Levent KOSAN

2014-10-01

Full Text Available Accounting, especially strategic management accounting, provides significant contributions to companies for decisions in environments of intense competition. Accounting, which has positive effects of company strategy development and management, has become a required facet of marketing, another area that has gained significance. The aim of this study is to assess the contributions of accounting to marketing performance management and other areas related to marketing development and to evaluate the relationship and synergies between marketing and accounting with comparative examples.

Brillouin gain enhancement in nano-scale photonic waveguide

Science.gov (United States)

Nouri Jouybari, Soodabeh

2018-05-01

The enhancement of stimulated Brillouin scattering in nano-scale waveguides has a great contribution in the improvement of the photonic devices technology. The key factors in Brillouin gain are the electrostriction force and radiation pressure generated by optical waves in the waveguide. In this article, we have proposed a new scheme of nano-scale waveguide in which the Brillouin gain is considerably improved compared to the previously-reported schemes. The role of radiation pressure in the Brillouin gain was much higher than the role of the electrostriction force. The Brillouin gain strongly depends on the structural parameters of the waveguide and the maximum value of 12127 W-1 m-1 is obtained for the Brillouin gain.

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.

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.

Eyewitness identification: Bayesian information gain, base-rate effect equivalency curves, and reasonable suspicion.

Science.gov (United States)

Wells, Gary L; Yang, Yueran; Smalarz, Laura

2015-04-01

We provide a novel Bayesian treatment of the eyewitness identification problem as it relates to various system variables, such as instruction effects, lineup presentation format, lineup-filler similarity, lineup administrator influence, and show-ups versus lineups. We describe why eyewitness identification is a natural Bayesian problem and how numerous important observations require careful consideration of base rates. Moreover, we argue that the base rate in eyewitness identification should be construed as a system variable (under the control of the justice system). We then use prior-by-posterior curves and information-gain curves to examine data obtained from a large number of published experiments. Next, we show how information-gain curves are moderated by system variables and by witness confidence and we note how information-gain curves reveal that lineups are consistently more proficient at incriminating the guilty than they are at exonerating the innocent. We then introduce a new type of analysis that we developed called base rate effect-equivalency (BREE) curves. BREE curves display how much change in the base rate is required to match the impact of any given system variable. The results indicate that even relatively modest changes to the base rate can have more impact on the reliability of eyewitness identification evidence than do the traditional system variables that have received so much attention in the literature. We note how this Bayesian analysis of eyewitness identification has implications for the question of whether there ought to be a reasonable-suspicion criterion for placing a person into the jeopardy of an identification procedure. (c) 2015 APA, all rights reserved).

Quality Management and Key Performance Indicators in Oncologic Esophageal Surgery.

Science.gov (United States)

Gockel, Ines; Ahlbrand, Constantin Johannes; Arras, Michael; Schreiber, Elke Maria; Lang, Hauke

2015-12-01

Ranking systems and comparisons of quality and performance indicators will be of increasing relevance for complex "high-risk" procedures such as esophageal cancer surgery. The identification of evidence-based standards relevant for key performance indicators in esophageal surgery is essential for establishing monitoring systems and furthermore a requirement to enhance treatment quality. In the course of this review, we analyze the key performance indicators case volume, radicality of resection, and postoperative morbidity and mortality, leading to continuous quality improvement. Ranking systems established on this basis will gain increased relevance in highly complex procedures within the national and international comparison and furthermore improve the treatment of patients with esophageal carcinoma.

Active mode-locking of mid-infrared quantum cascade lasers with short gain recovery time.

Science.gov (United States)

Wang, Yongrui; Belyanin, Alexey

2015-02-23

We investigate the dynamics of actively modulated mid-infrared quantum cascade lasers (QCLs) using space- and time-domain simulations of coupled density matrix and Maxwell equations with resonant tunneling current taken into account. We show that it is possible to achieve active mode locking and stable generation of picosecond pulses in high performance QCLs with a vertical laser transition and a short gain recovery time by bias modulation of a short section of a monolithic Fabry-Perot cavity. In fact, active mode locking in QCLs with a short gain recovery time turns out to be more robust to the variation of parameters as compared to previously studied lasers with a long gain recovery time. We investigate the effects of spatial hole burning and phase locking on the laser output.

Net energy gain from DT fusion

International Nuclear Information System (INIS)

Buende, R.

1985-01-01

The net energy which can be gained from an energy raw material by means of a certain conversion system is deduced as the figure-of-merit which adequately characterizes the net energy balance of utilizing an energy source. This potential net energy gain is determined for DT fusion power plants. It is represented as a function of the degree of exploitation of the energy raw material lithium ore and is compared with the net energy which can be gained with LW and FBR power plants by exploiting uranium ore. The comparison clearly demonstrates the net energetic advantage of DT fusion. A sensitivity study shows that this holds even if the energy expenditure for constructing and operating is drastically increased

Inappropriate gestational weight gain among teenage pregnancies: prevalence and pregnancy outcomes.

Science.gov (United States)

Vivatkusol, Yada; Thavaramara, Thaovalai; Phaloprakarn, Chadakarn

2017-01-01

To study the prevalence and pregnancy outcomes of inappropriate gestational weight gain (GWG) among teenage pregnant women. A retrospective descriptive study was conducted on 2,165 teenage pregnant women who attended our antenatal clinic between January 2007 and August 2015. Adverse pregnancy outcomes, including maternal and neonatal outcomes of women with inappropriate GWG, including underweight and overweight, were studied and compared with those of women with appropriate GWG. Complete data of 1,943 women were obtained. Among these women, the mean age was 17.4±1.4 years and mean body mass index at first visit was 19.1±3.0 kg/m 2 . The prevalence of inappropriate GWG was 61.7%. Underweight women were more likely to experience anemia and preterm delivery, whereas overweight women required more cesarean sections because of cephalopelvic disproportion and preeclampsia, compared to women with appropriate weight gain (all P teenage pregnancies showed inappropriate GWG. GWG had a significant impact on pregnancy outcomes.

Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use

Directory of Open Access Journals (Sweden)

Dar eMeshi

2013-08-01

Full Text Available Our reputation is important to us; we’ve experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one’s character has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others’ behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one’s degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior.

Tuning of gravity-dependent and gravity-independent vertical angular VOR gain changes by frequency of adaptation.

Science.gov (United States)

Yakushin, Sergei B

2012-06-01

The gain of the vertical angular vestibulo-ocular reflex (aVOR) was adaptively increased and decreased in a side-down head orientation for 4 h in two cynomolgus monkeys. Adaptation was performed at 0.25, 1, 2, or 4 Hz. The gravity-dependent and -independent gain changes were determined over a range of head orientations from left-side-down to right-side-down at frequencies from 0.25 to 10 Hz, before and after adaptation. Gain changes vs. frequency data were fit with a Gaussian to determine the frequency at which the peak gain change occurred, as well as the tuning width. The frequency at which the peak gravity-dependent gain change occurred was approximately equal to the frequency of adaptation, and the width increased monotonically with increases in the frequency of adaptation. The gravity-independent component was tuned to the adaptive frequency of 0.25 Hz but was uniformly distributed over all frequencies when the adaptation frequency was 1-4 Hz. The amplitude of the gravity-independent gain changes was larger after the aVOR gain decrease than after the gain increase across all tested frequencies. For the aVOR gain decrease, the phase lagged about 4° for frequencies below the adaptation frequency and led for frequencies above the adaptation frequency. For gain increases, the phase relationship as a function of frequency was inverted. This study demonstrates that the previously described dependence of aVOR gain adaptation on frequency is a property of the gravity-dependent component of the aVOR only. The gravity-independent component of the aVOR had a substantial tuning curve only at an adaptation frequency of 0.25 Hz.

The CHOP postnatal weight gain, birth weight, and gestational age retinopathy of prematurity risk model.

Science.gov (United States)

Binenbaum, Gil; Ying, Gui-Shuang; Quinn, Graham E; Huang, Jiayan; Dreiseitl, Stephan; Antigua, Jules; Foroughi, Negar; Abbasi, Soraya

2012-12-01

To develop a birth weight (BW), gestational age (GA), and postnatal-weight gain retinopathy of prematurity (ROP) prediction model in a cohort of infants meeting current screening guidelines. Multivariate logistic regression was applied retrospectively to data from infants born with BW less than 1501 g or GA of 30 weeks or less at a single Philadelphia hospital between January 1, 2004, and December 31, 2009. In the model, BW, GA, and daily weight gain rate were used repeatedly each week to predict risk of Early Treatment of Retinopathy of Prematurity type 1 or 2 ROP. If risk was above a cut-point level, examinations would be indicated. Of 524 infants, 20 (4%) had type 1 ROP and received laser treatment; 28 (5%) had type 2 ROP. The model (Children's Hospital of Philadelphia [CHOP]) accurately predicted all infants with type 1 ROP; missed 1 infant with type 2 ROP, who did not require laser treatment; and would have reduced the number of infants requiring examinations by 49%. Raising the cut point to miss one type 1 ROP case would have reduced the need for examinations by 79%. Using daily weight measurements to calculate weight gain rate resulted in slightly higher examination reduction than weekly measurements. The BW-GA-weight gain CHOP ROP model demonstrated accurate ROP risk assessment and a large reduction in the number of ROP examinations compared with current screening guidelines. As a simple logistic equation, it can be calculated by hand or represented as a nomogram for easy clinical use. However, larger studies are needed to achieve a highly precise estimate of sensitivity prior to clinical application.

A new approach to assess student perceptions of gains from an REU program

Science.gov (United States)

Houser, C.; Cahill, A. T.; Lemmons, K.

2013-12-01

Research Experience for Undergraduate (REU) programs are designed to recruit students to science and engineering research careers by allowing the students to conduct research with faculty mentors. The success of REU programs is commonly assessed based on student perceptions of gains using a simple Likert scale. Because students tend to be positive about all aspects of their research experience, the results of the Likert scale tend to be meaningless. An alternative assessment technique, similar to Q-analysis, is used to assess the perceived outcomes of an international REU program hosted by Texas A&M University. Students were required to sort commonly identified REU outcomes into a normal distribution, from most agree to least agree, based on what they perceive as their personal gains from the program. Factor analysis reveals 3 groups of students who believe that they gained field and analytical skills (Group 1), greater competence in research and self-confidence (Group 2), and an improved understanding of the scientific method (Group 3). Student perceptions appear to depend on whether the student had previous research experience through classes and/or as a research assistant at their home institution. A comparison to a similar sort of REU outcomes by the faculty mentors suggests that there is a slight disconnect in the perceived gains by the students between the student participants and the faculty mentors.

Weight gain of piglets subject to different protocols of castration

Directory of Open Access Journals (Sweden)

Marcos Paulo Antunes de Lima

2014-06-01

Full Text Available ABSTRACT. Lima M.P.A., Gehrcke M.I., Laskoski F., Cristani J. & Oleskovicz N. [Weight gain of piglets subject to different protocols of castration.] Desempenho de ganho de peso de leitões após diferentes protocolos de castração. Revista Brasileira de Medicina Veterinária, 36(2:209-214, 2014. Departamento de Medicina Veterinária, Centro de Ciências Agroveterinárias, Universidade do Estado de Santa Catarina, Av. Luiz de Camões 2090, Conta Dinheiro, Lages, SC 88520-000, Brasil. E-mail: marcos_paulo@hotmail.com The aim this study was to evaluate the performance of weight gain of piglets castrated, and three methods of sedation and or local anesthesia compared with the traditional method recommended by the standards of Good Practices in Swine Production. We used 100 male pigs, seven days old, weighing 2.9 ± 0.50 kg, which were randomly divided into four groups: (BP Practice, in which the animals were castrated without anesthesia or analgesia, L (Lidocaine, which received 0.5 mL of lidocaine without epinephrine in each spermatic cord; SL (sedation/lidocaine which were sedated with tramadol 4mg.kg-1 and midazolam 1 mg.kg-1 intramuscular (IM, associated with the local block with 0.5 mL of lidocaine without epinephrine administered in each spermatic cord, and S (sedation, which received tramadol 4mg.kg-1 and midazolam 1mg.kg-1 IM. Recorded the weight of the animals at birth, the seventh day preceding the castration procedure, and 20 days old at the time of weaning. The data were evaluated by One Way ANOVA (ANOVA followed by Tukey test (P<0.05. The mean weights of animals at weaning were 6.15±0.86, 6.02±1.06, 5.96±0.19 and 5.51±1.14 and the average daily weight gain, the day of Castration at weaning was 0.23±0.05, 0.24±0.04, 0.23±0.06 and 0.19±0.05 respectively, for BP groups, L, SL and S. There were no significant differences between the values of the groups studied. The use of sedation protocols and or anesthetic to perform the

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

Estimation of waste package performance requirements for a nuclear waste repository in basalt

International Nuclear Information System (INIS)

Wood, B.J.

1980-07-01

A method of developing waste package performance requirements for specific nuclides is described, and based on federal regulations concerning permissible concentrations in solution at the point of discharge to the accessible environment, a simple and conservative transport model, and baseline and potential worst-case release scenarios

When, How and Why is Loss-Framing More Effective than Gain- and Non-Gain-Framing in the Promotion of Detection Behaviors?

OpenAIRE

Bosone, Lucia; Martinez, Frédéric

2017-01-01

This short paper aims to untangle the effect of loss-framing versus gain and non-gain; explaining when, how and why it influences individuals’ intentions to engage in cholesterol screening. We argue that framing-effects are (1) significant only when individuals perceive the issue to be highly relevant and (2) are mediated by perceived negative consequences (resulting from undergoing the test) and response-efficacy. In a 2(issue-relevance: high vs low) × 3(framing: gain vs non-gain vs loss) ex...

Weight gain after bariatric surgery as a result of a large gastric stoma: endotherapy with sodium morrhuate may prevent the need for surgical revision.

Science.gov (United States)

Catalano, Marc F; Rudic, Goran; Anderson, Alfred J; Chua, Thomas Y

2007-08-01

Obesity affects more than 30% of the U.S. population and is associated with the development of life-threatening complications. Numerous therapeutic approaches to the problem have been advocated, including low-calorie diets, anoretic drugs, behavior modifications, and exercise therapy. The only treatment proven to be effective in the long-term management of morbid obesity is surgical intervention. Complications of bariatric surgery include stomal stenosis and/or ulcer and stomal dilation (secondary to overeating). The latter complication can result in a gain of previously lost weight. To determine the effect of endoscopic injection by using a sclerosant (sodium morrhuate) to induce stomal stenosis in patients who present with stomal dilatation complicated by weight gain. Bariatric patients with a large gastric stoma were treated with sodium morrhuate stomal injection. Diameters of the stoma were followed at repeat endoscopy. Weight loss at scheduled clinic visits were compared with pretherapy weights. Twenty-eight patients (10 men, 18 women; age range, 27-58 years), after bariatric surgery with GI bypass, were referred with weight gain after initial weight loss. Weight gain was believed to be the result of a large gastric stoma. Treatment included injection of sodium morrhuate (1-2 mL circumferentially) surrounding the stoma. A total of 1 to 3 injection sessions were performed in an attempt to achieve a stoma diameter of 1.2 cm or smaller. Treatment success was defined as a decrease of stoma size to weight loss >or=75% of the weight the patient gained after establishing a steady state post bariatric surgery weight. A total of 2.3 injection sessions were performed. Successful endotherapy was achieved in 18 of 28 patients (64%). One patient developed symptoms of stomal stenosis, which required 2 separate balloon dilating sessions. No other complications were encountered. Retrospective case series. Endoscopic injection of sodium morrhuate surrounding the dilated

Effect of computer mouse gain and visual demand on mouse clicking performance and muscle activation in a young and elderly group of experienced computer users

DEFF Research Database (Denmark)

Sandfeld, Jesper; Jensen, Bente R.

2005-01-01

and three levels of target size were used. All subjects demonstrated a reduced working speed and hit rate at the highest mouse gain (1:8) when the target size was small. The young group had an optimum at mouse gain 1:4. The elderly group was most sensitive to the combination of high mouse gain and small...

24 CFR 3280.506 - Heat loss/heat gain.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Heat loss/heat gain. 3280.506... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat loss/heat gain. The manufactured home heat loss/heat gain shall be determined by methods outlined in...

Determinants of Weight Gain During Adjuvant Endocrine Therapy and Association of Such Weight Gain With Recurrence in Long-term Breast Cancer Survivors.

Science.gov (United States)

Raghavendra, Akshara; Sinha, Arup K; Valle-Goffin, Janeiro; Shen, Yu; Tripathy, Debu; Barcenas, Carlos H

2018-02-01

Weight gain is a negative prognostic factor in breast cancer (BC) patients. The risk factors for weight gain during adjuvant endocrine therapy (ET) and the extent to which such weight gain is associated with disease recurrence remain unclear. We retrospectively identified a cohort of women with a diagnosis of stage I-III, hormone receptor-positive, human epidermal growth factor receptor 2-negative BC from January 1997 to August 2008, who had received initial treatment at the MD Anderson Cancer Center, had completed 5 years of ET, and had remained free of locoregional or distant relapse or contralateral BC for ≥ 5 years after diagnosis. The weight change at the end of 5 years of ET was measured as the percentage of the change in weight from the start of ET, with a weight gain of > 5% considered clinically significant. Multivariable logistic regression and Cox proportional hazards models were used to assess the determinants of such weight gain and the risk of recurrence after 5 years. Of 1282 long-term BC survivors, 432 (33.7%) had a weight gain of > 5% after 5 years of ET. Women who were premenopausal at diagnosis were 1.40 times more likely than women who were postmenopausal at diagnosis to have a weight gain of > 5%. Asian women had the lowest risk of gaining weight. The recurrence risks of patients who had gained weight and those who had not were not significantly different. Premenopausal BC patients had an increased risk of weight gain after 5 years of ET; however, BC patients with a weight gain of > 5% did not have an increased risk of disease recurrence. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

Optical properties of nanowire metamaterials with gain

DEFF Research Database (Denmark)

Isidio de Lima, Joaquim Junior; Adam, Jost; Rego, Davi

2016-01-01

The transmittance, reflectance and absorption of a nanowire metamaterial with optical gain are numerically simulated and investigated. It is assumed that the metamaterial is represented by aligned silver nanowires embedded into a semiconductor matrix, made of either silicon or gallium phosphide....... The gain in the matrix is modeled by adding a negative imaginary part to the dielectric function of the semiconductor. It is found that the optical coefficients of the metamaterial depend on the gain magnitude in a non-trivial way: they can both increase and decrease with gain depending on the lattice...... constant of the metamaterial. This peculiar behavior is explained by the field redistribution between the lossy metal nanowires and the amplifying matrix material. These findings are significant for a proper design of nanowire metamaterials with low optical losses for diverse applications....

Association of Timing of Weight Gain in Pregnancy With Infant Birth Weight.

Science.gov (United States)

Retnakaran, Ravi; Wen, Shi Wu; Tan, Hongzhuan; Zhou, Shujin; Ye, Chang; Shen, Minxue; Smith, Graeme N; Walker, Mark C

2018-02-01

Gestational weight gain is a determinant of infant birth weight, but it is unclear whether its timing in pregnancy may hold implications in this regard. Previous studies have yielded conflicting findings on the association of maternal weight gain in early pregnancy with birth weight. However, as these studies have typically recruited women during the first trimester, they are inherently limited by a reliance on self-reported pregravid weight. To evaluate the associations of directly measured maternal pregravid weight and the timing of subsequent weight gain across pregnancy with infant birth weight. In this prospective, preconception, observational cohort study, 1164 newly married women in Liuyang, China, underwent pregravid evaluation at a median of 19.9 weeks before a singleton pregnancy during which they underwent serial weight measurements. The study was conducted from February 1, 2009, to November 4, 2015. Data analysis was performed between September 1, 2016, and May 6, 2017. Maternal weight gain was calculated for the following 10 gestational intervals: from pregravid to less than 14, 14 to 18, 19 to 23, 24 to 28, 29 to 30, 31 to 32, 33 to 34, 35 to 36, 37 to 38, and 39 to 40 weeks. Associations of pregravid weight and weight gain within each of the 10 gestational intervals with the outcome of infant birth weight. The mean (SD) age of the 1164 women included in the study was 25.3 (3.1) years. Pregravid weight was consistently associated with infant birth weight. However, among the 10 gestational intervals, only weight gain from pregravid to 14 weeks and from 14 to 18 weeks was associated with birth weight. Birth weight increased by 13.6 g/kg (95% CI, 3.2-24.1 g/kg) of maternal weight gain from pregravid to 14 weeks and by 26.1 g/kg (95% CI, 3.8-48.4 g/kg) of maternal weight gain from 14 to 18 weeks. Maternal weight only in the first half of gestation is a determinant of infant birth weight. Before pregnancy and early gestation may be a critical window for

Heuristic Portfolio Trading Rules with Capital Gain Taxes

DEFF Research Database (Denmark)

Fischer, Marcel; Gallmeyer, Michael

in some cases. Overlaying simple tax trading heuristics on these trading strategies improves out-of-sample performance. In particular, the 1/N trading strategy's welfare gains improve when a variety of tax trading heuristics are also imposed. For medium to large transaction costs, no trading strategy can...... outperform a 1/N trading strategy augmented with a tax heuristic, not even the most tax- and transaction-cost efficient buy-and-hold strategy. Overall, the best strategy is 1/N augmented with a heuristic that allows for a fixed deviation in absolute portfolio weights. Our results show that the best trading...

Weight gain in women diagnosed with breast cancer.

Science.gov (United States)

Demark-Wahnefried, W; Rimer, B K; Winer, E P

1997-05-01

This review of the literature indicates that weight gain is a common observation among women after the diagnosis of breast cancer. Gains in weight range from 0 to 50 lb and are influenced by menopausal status; nodal status; and the type, duration, and intensity of treatment. Weight gain appears to be greater among premenopausal women; among those who are node positive; and among those receiving higher dose, longer duration, and multiagent regimens. Psychosocial research suggests that weight gain has a profoundly negative impact on quality of life in patients with breast cancer. Recent findings also suggest that weight gain during therapy may increase the risk of recurrence and decrease survival. Although weight gain in patients with breast cancer is clinically well appreciated, little research has been conducted to investigate the underlying mechanisms of energy imbalance. Changes in rates of metabolism, physical activity, and dietary intake are all plausible mechanisms and call for more research. Further study will provide valuable insight into the problem of weight gain and encourage effective interventions to improve the quality and quantity of life for the woman with breast cancer. Until more is known, however, dietetics practitioners will have to monitor and work individually with patients with breast cancer and use empirical approaches to achieve the important goal of weight management.

The influence of place on weight gain during early childhood: a population-based, longitudinal study.

Science.gov (United States)

Carter, Megan Ann; Dubois, Lise; Tremblay, Mark S; Taljaard, Monica

2013-04-01

The objective of this paper was to determine the influence of place factors on weight gain in a contemporary cohort of children while also adjusting for early life and individual/family social factors. Participants from the Québec Longitudinal Study of Child Development comprised the sample for analysis (n = 1,580). A mixed-effects regression analysis was conducted to determine the longitudinal relationship between these place factors and standardized BMI, from age 4 to 10 years. The average relationship with time was found to be quadratic (rate of weight gain increased over time). Neighborhood material deprivation was found to be positively related to weight gain. Social deprivation, social disorder, and living in a medium density area were inversely related, while no association was found for social cohesion. Early life factors and genetic proxies appeared to be important in explaining weight gain in this sample. This study suggests that residential environments may play a role in childhood weight change; however, pathways are likely to be complex and interacting and perhaps not as important as early life factors and genetic proxies. Further work is required to clarify these relationships.

High D(+-Fructose Diet Adversely Affects Testicular Weight Gain in Weaning Rats—Protection by Moderate D(+-Glucose Diet

Directory of Open Access Journals (Sweden)

Katsumi Shibata

2013-01-01

Full Text Available The use of high D(+-fructose corn syrup has increased over the past several decades in the developed countries, while overweight and obesity rates and the related diseases have risen dramatically. However, we found that feeding a high D(+-fructose diet (80% D(+-fructose as part of the diet to weaning rats for 21 days led to reduced food intake (50% less, P < 0.0001 and thus delayed the weight gains in the body (40% less, P < 0.0001 and testes (40% less, P < 0.0001 compared to the no D(+-fructose diet. We also challenged a minimum requirement of dietary D(+-glucose for preventing the adverse effects of D(+-fructose, such as lower food intake and reduction of body weight and testicular weight; the minimum requirement of D(+-glucose was ã23% of the diet. This glucose amount may be the minimum requirement of exogenous glucose for reducing weight gain.

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.

Maximum gain of Yagi-Uda arrays

DEFF Research Database (Denmark)

Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

1971-01-01

Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

Conceptual design of a 10-MJ driver for a high gain target development facility

International Nuclear Information System (INIS)