Carbohydrate and Caffeine Mouth Rinses Do Not Affect Maximum Strength and Muscular Endurance Performance.

PubMed

Clarke, Neil D; Kornilios, Evangelos; Richardson, Darren L

2015-10-01

Oral carbohydrate (CHO) rinsing has beneficial effects on endurance performance and caffeine (CAF) mouth rinsing either independently or in conjunction with CHO may enhance sprinting performance. However, the effects of CHO and CAF mouth rinses on resistance exercise have not been examined previously. The purpose of this study was to investigate the effects of CHO and CAF rinsing on maximum strength and muscular endurance performance. Fifteen recreationally resistance-trained males completed an exercise protocol, which involved a 1 repetition maximum (RM) bench press followed by 60% of their 1RM to failure in a double-blind, randomized, counterbalanced crossover design. Before exercise, 25 ml of a 6% (15 g; 0.20 ± 0.02 g·kg(-1)) CHO, 1.2% (300 mg; 3.9 ± 0.3 mg·kg(-1)) CAF, carbohydrate with caffeine (C + C) solutions, or water (placebo; PLA) were rinsed for 10 seconds. During the remaining session, no solution was rinsed (control; CON). All solutions were flavored with (200 mg) sucralose. Felt arousal was recorded pre- and post-rinse, and rating of perceived exertion (RPE) was recorded immediately after the repetitions to failure. There were no significant differences in 1RM (p = 0.808; ηp(2)= 0.02), the number of repetitions performed (p = 0.682; ηp(2)= 0.03), or the total exercise volume (p = 0.482; ηp(2)= 0.03) between conditions. Rating of perceived exertion was similar for all trials (p = 0.330; ηp(2)= 0.08), whereas Felt arousal increased as a consequence of rinsing (p = 0.001; ηp(2)= 0.58), but was not different between trials (p = 0.335; ηp(2)= 0.08). These results suggest that rinsing with a CHO and CAF solution either independently or combined has no significant effect on maximum strength or muscular endurance performance.

Maximum Correntropy Unscented Kalman Filter for Spacecraft Relative State Estimation.

PubMed

Liu, Xi; Qu, Hua; Zhao, Jihong; Yue, Pengcheng; Wang, Meng

2016-09-20

A new algorithm called maximum correntropy unscented Kalman filter (MCUKF) is proposed and applied to relative state estimation in space communication networks. As is well known, the unscented Kalman filter (UKF) provides an efficient tool to solve the non-linear state estimate problem. However, the UKF usually plays well in Gaussian noises. Its performance may deteriorate substantially in the presence of non-Gaussian noises, especially when the measurements are disturbed by some heavy-tailed impulsive noises. By making use of the maximum correntropy criterion (MCC), the proposed algorithm can enhance the robustness of UKF against impulsive noises. In the MCUKF, the unscented transformation (UT) is applied to obtain a predicted state estimation and covariance matrix, and a nonlinear regression method with the MCC cost is then used to reformulate the measurement information. Finally, the UT is adopted to the measurement equation to obtain the filter state and covariance matrix. Illustrative examples demonstrate the superior performance of the new algorithm.

Maximum Correntropy Unscented Kalman Filter for Spacecraft Relative State Estimation

PubMed Central

Liu, Xi; Qu, Hua; Zhao, Jihong; Yue, Pengcheng; Wang, Meng

2016-01-01

A new algorithm called maximum correntropy unscented Kalman filter (MCUKF) is proposed and applied to relative state estimation in space communication networks. As is well known, the unscented Kalman filter (UKF) provides an efficient tool to solve the non-linear state estimate problem. However, the UKF usually plays well in Gaussian noises. Its performance may deteriorate substantially in the presence of non-Gaussian noises, especially when the measurements are disturbed by some heavy-tailed impulsive noises. By making use of the maximum correntropy criterion (MCC), the proposed algorithm can enhance the robustness of UKF against impulsive noises. In the MCUKF, the unscented transformation (UT) is applied to obtain a predicted state estimation and covariance matrix, and a nonlinear regression method with the MCC cost is then used to reformulate the measurement information. Finally, the UT is adopted to the measurement equation to obtain the filter state and covariance matrix. Illustrative examples demonstrate the superior performance of the new algorithm. PMID:27657069

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

NASA Astrophysics Data System (ADS)

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

2011-04-01

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

Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario.

PubMed

Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

2014-07-07

In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.

Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario

NASA Astrophysics Data System (ADS)

Chen, Xi Lin; De Santis, Valerio; Esai Umenei, Aghuinyue

2014-07-01

In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.

Ankle moment generation and maximum-effort curved sprinting performance.

PubMed

Luo, Geng; Stefanyshyn, Darren

2012-11-15

Turning at high speed along acute curves is crucial for athletic performance. One determinant of curved sprinting speed is the ground reaction force that can be created by the supporting limb; the moment generated at the ankle joint may influence such force generation. Body lean associated with curved sprints positions the ankle joints in extreme in-/eversion, and may hinder the ankle moment generation. To examine the influence of ankle moment generation on curved sprinting performance, 17 male subjects performed maximum-effort curved sprints in footwear with and without a wedge. The wedged footwear was constructed with the intention to align the ankle joints closer to their neutral frontal-plane configuration during counter-clockwise curved sprints so greater joint moments might be generated. We found, with the wedged footwear, the average eversion angle of the inside leg ankle was reduced, and the plantarflexion moment generation increased significantly. Meanwhile, the knee extension moment remained unchanged. With the wedged footwear, stance-average centripetal ground reaction force increased significantly while no difference in the vertical ground reaction force was detected. The subjects created a greater centripetal ground reaction impulse in the wedged footwear despite a shortened stance phase when compared to the control. Stance-average curved sprinting speed improved by 4.3% with the wedged footwear. The changes in ankle moment and curved sprinting speed observed in the current study supports the notion that the moment generation at the ankle joint may be a performance constraint for curved sprinting. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Systematic Approach for Obtaining Performance on Matrix-Like Operations

NASA Astrophysics Data System (ADS)

Veras, Richard Michael

Scientific Computation provides a critical role in the scientific process because it allows us ask complex queries and test predictions that would otherwise be unfeasible to perform experimentally. Because of its power, Scientific Computing has helped drive advances in many fields ranging from Engineering and Physics to Biology and Sociology to Economics and Drug Development and even to Machine Learning and Artificial Intelligence. Common among these domains is the desire for timely computational results, thus a considerable amount of human expert effort is spent towards obtaining performance for these scientific codes. However, this is no easy task because each of these domains present their own unique set of challenges to software developers, such as domain specific operations, structurally complex data and ever-growing datasets. Compounding these problems are the myriads of constantly changing, complex and unique hardware platforms that an expert must target. Unfortunately, an expert is typically forced to reproduce their effort across multiple problem domains and hardware platforms. In this thesis, we demonstrate the automatic generation of expert level high-performance scientific codes for Dense Linear Algebra (DLA), Structured Mesh (Stencil), Sparse Linear Algebra and Graph Analytic. In particular, this thesis seeks to address the issue of obtaining performance on many complex platforms for a certain class of matrix-like operations that span across many scientific, engineering and social fields. We do this by automating a method used for obtaining high performance in DLA and extending it to structured, sparse and scale-free domains. We argue that it is through the use of the underlying structure found in the data from these domains that enables this process. Thus, obtaining performance for most operations does not occur in isolation of the data being operated on, but instead depends significantly on the structure of the data.

A study comparing precision of the maximum multipoint heterogeneity LOD statistic to three model-free multipoint linkage methods.

PubMed

Finch, S J; Chen, C H; Gordon, D; Mendell, N R

2001-12-01

This study compared the performance of the maximum lod (MLOD), maximum heterogeneity lod (MHLOD), maximum non-parametric linkage score (MNPL), maximum Kong and Cox linear extension (MKC(lin)) of NPL, and maximum Kong and Cox exponential extension (MKC(exp)) of NPL as calculated in Genehunter 1.2 and Genehunter-Plus. Our performance measure was the distance between the marker with maximum value for each linkage statistic and the trait locus. We performed a simulation study considering: 1) four modes of transmission, 2) 100 replicates for each model, 3) 58 pedigrees (with 592 subjects) per replicate, 4) three linked marker loci each having three equally frequent alleles, and 5) either 0% unlinked families (linkage homogeneity) or 50% unlinked families (linkage heterogeneity). For each replicate, we obtained the Haldane map position of the location at which each of the five statistics is maximized. The MLOD and MHLOD were obtained by maximizing over penetrances, phenocopy rate, and risk-allele frequencies. For the models simulated, MHLOD appeared to be the best statistic both in terms of identifying a marker locus having the smallest mean distance from the trait locus and in terms of the strongest negative correlation between maximum linkage statistic and distance of the identified position and the trait locus. The marker loci with maximum value of the Kong and Cox extensions of the NPL statistic also were closer to the trait locus than the marker locus with maximum value of the NPL statistic. Copyright 2001 Wiley-Liss, Inc.

Maximum thrust mode evaluation

NASA Technical Reports Server (NTRS)

Orme, John S.; Nobbs, Steven G.

1995-01-01

Measured reductions in acceleration times which resulted from the application of the F-15 performance seeking control (PSC) maximum thrust mode during the dual-engine test phase is presented as a function of power setting and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and maximum afterburning power settings. The time savings for the supersonic acceleration is less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Recall that even though the engine is at maximum afterburner, PSC does not trim the afterburner for the maximum thrust mode. Subsonically at military power, time to accelerate from Mach 0.6 to 0.95 was cut by between 6 and 8 percent with a single engine application of PSC, and over 14 percent when both engines were optimized. At maximum afterburner, the level of thrust increases were similar in magnitude to the military power results, but because of higher thrust levels at maximum afterburner and higher aircraft drag at supersonic Mach numbers the percentage thrust increase and time to accelerate was less than for the supersonic accelerations. Savings in time to accelerate supersonically at maximum afterburner ranged from 4 to 7 percent. In general, the maximum thrust mode has performed well, demonstrating significant thrust increases at military and maximum afterburner power. Increases of up to 15 percent at typical combat-type flight conditions were identified. Thrust increases of this magnitude could be useful in a combat situation.

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1975-01-01

A general iterative procedure is given for determining the consistent maximum likelihood estimates of normal distributions. In addition, a local maximum of the log-likelihood function, Newtons's method, a method of scoring, and modifications of these procedures are discussed.

DSN telemetry system performance with convolutionally coded data using operational maximum-likelihood convolutional decoders

NASA Technical Reports Server (NTRS)

Benjauthrit, B.; Mulhall, B.; Madsen, B. D.; Alberda, M. E.

1976-01-01

The DSN telemetry system performance with convolutionally coded data using the operational maximum-likelihood convolutional decoder (MCD) being implemented in the Network is described. Data rates from 80 bps to 115.2 kbps and both S- and X-band receivers are reported. The results of both one- and two-way radio losses are included.

Maximum performance synergy: A new approach to recording studio control room design

NASA Astrophysics Data System (ADS)

Szymanski, Jeff D.

2003-10-01

Popular recording studio control room designs include LEDE(tm), RFZ(tm), and nonenvironment rooms. The common goal of all of these is to create an accurate acoustical environment that does not distort or otherwise color audio reproduction. Also common to these designs is the frequent need to have multiple ancillary recording rooms, often adjacent to the main control room, where group members perform. This approach, where group members are physically separated from one another, can lead to lack of ensemble in the finished recordings. New twists on old acoustical treatment techniques have been implemented at a studio in Nashville, Tennessee, which minimize the need for multiple ancillary recording rooms, thus creating an environment where talent, producer and recording professionals can all occupy the same space for maximum performance synergy. Semi-separated performance areas are designed around a central, critical listening area. The techniques and equipment required to achieve this separation are reviewed, as are advantages and disadvantages to this new control room design approach.

16QAM Blind Equalization via Maximum Entropy Density Approximation Technique and Nonlinear Lagrange Multipliers

PubMed Central

Mauda, R.; Pinchas, M.

2014-01-01

Recently a new blind equalization method was proposed for the 16QAM constellation input inspired by the maximum entropy density approximation technique with improved equalization performance compared to the maximum entropy approach, Godard's algorithm, and others. In addition, an approximated expression for the minimum mean square error (MSE) was obtained. The idea was to find those Lagrange multipliers that bring the approximated MSE to minimum. Since the derivation of the obtained MSE with respect to the Lagrange multipliers leads to a nonlinear equation for the Lagrange multipliers, the part in the MSE expression that caused the nonlinearity in the equation for the Lagrange multipliers was ignored. Thus, the obtained Lagrange multipliers were not those Lagrange multipliers that bring the approximated MSE to minimum. In this paper, we derive a new set of Lagrange multipliers based on the nonlinear expression for the Lagrange multipliers obtained from minimizing the approximated MSE with respect to the Lagrange multipliers. Simulation results indicate that for the high signal to noise ratio (SNR) case, a faster convergence rate is obtained for a channel causing a high initial intersymbol interference (ISI) while the same equalization performance is obtained for an easy channel (initial ISI low). PMID:24723813

One repetition maximum bench press performance: a new approach for its evaluation in inexperienced males and females: a pilot study.

PubMed

Bianco, Antonino; Filingeri, Davide; Paoli, Antonio; Palma, Antonio

2015-04-01

The aim of this study was to evaluate a new method to perform the one repetition maximum (1RM) bench press test, by combining previously validated predictive and practical procedures. Eight young male and 7 females participants, with no previous experience of resistance training, performed a first set of repetitions to fatigue (RTF) with a workload corresponding to ⅓ of their body mass (BM) for a maximum of 25 repetitions. Following a 5-min recovery period, a second set of RTF was performed with a workload corresponding to ½ of participants' BM. The number of repetitions performed in this set was then used to predict the workload to be used for the 1RM bench press test using Mayhew's equation. Oxygen consumption, heart rate and blood lactate were monitored before, during and after each 1RM attempt. A significant effect of gender was found on the maximum number of repetitions achieved during the RTF set performed with ½ of participants' BM (males: 25.0 ± 6.3; females: 11.0x± 10.6; t = 6.2; p < 0.001). The 1RM attempt performed with the workload predicted by Mayhew's equation resulted in females performing 1.2 ± 0.7 repetitions, while males performed 4.8 ± 1.9 repetitions. All participants reached their 1RM performance within 3 attempts, thus resulting in a maximum of 5 sets required to successfully perform the 1RM bench press test. We conclude that, by combining previously validated predictive equations with practical procedures (i.e. using a fraction of participants' BM to determine the workload for an RTF set), the new method we tested appeared safe, accurate (particularly in females) and time-effective in the practical evaluation of 1RM performance in inexperienced individuals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Selection of the Maximum Spatial Cluster Size of the Spatial Scan Statistic by Using the Maximum Clustering Set-Proportion Statistic.

PubMed

Ma, Yue; Yin, Fei; Zhang, Tao; Zhou, Xiaohua Andrew; Li, Xiaosong

2016-01-01

Spatial scan statistics are widely used in various fields. The performance of these statistics is influenced by parameters, such as maximum spatial cluster size, and can be improved by parameter selection using performance measures. Current performance measures are based on the presence of clusters and are thus inapplicable to data sets without known clusters. In this work, we propose a novel overall performance measure called maximum clustering set-proportion (MCS-P), which is based on the likelihood of the union of detected clusters and the applied dataset. MCS-P was compared with existing performance measures in a simulation study to select the maximum spatial cluster size. Results of other performance measures, such as sensitivity and misclassification, suggest that the spatial scan statistic achieves accurate results in most scenarios with the maximum spatial cluster sizes selected using MCS-P. Given that previously known clusters are not required in the proposed strategy, selection of the optimal maximum cluster size with MCS-P can improve the performance of the scan statistic in applications without identified clusters.

Selection of the Maximum Spatial Cluster Size of the Spatial Scan Statistic by Using the Maximum Clustering Set-Proportion Statistic

PubMed Central

Ma, Yue; Yin, Fei; Zhang, Tao; Zhou, Xiaohua Andrew; Li, Xiaosong

2016-01-01

Spatial scan statistics are widely used in various fields. The performance of these statistics is influenced by parameters, such as maximum spatial cluster size, and can be improved by parameter selection using performance measures. Current performance measures are based on the presence of clusters and are thus inapplicable to data sets without known clusters. In this work, we propose a novel overall performance measure called maximum clustering set–proportion (MCS-P), which is based on the likelihood of the union of detected clusters and the applied dataset. MCS-P was compared with existing performance measures in a simulation study to select the maximum spatial cluster size. Results of other performance measures, such as sensitivity and misclassification, suggest that the spatial scan statistic achieves accurate results in most scenarios with the maximum spatial cluster sizes selected using MCS-P. Given that previously known clusters are not required in the proposed strategy, selection of the optimal maximum cluster size with MCS-P can improve the performance of the scan statistic in applications without identified clusters. PMID:26820646

Analytical template protection performance and maximum key size given a Gaussian-modeled biometric source

NASA Astrophysics Data System (ADS)

Kelkboom, Emile J. C.; Breebaart, Jeroen; Buhan, Ileana; Veldhuis, Raymond N. J.

2010-04-01

Template protection techniques are used within biometric systems in order to protect the stored biometric template against privacy and security threats. A great portion of template protection techniques are based on extracting a key from or binding a key to a biometric sample. The achieved protection depends on the size of the key and its closeness to being random. In the literature it can be observed that there is a large variation on the reported key lengths at similar classification performance of the same template protection system, even when based on the same biometric modality and database. In this work we determine the analytical relationship between the system performance and the theoretical maximum key size given a biometric source modeled by parallel Gaussian channels. We consider the case where the source capacity is evenly distributed across all channels and the channels are independent. We also determine the effect of the parameters such as the source capacity, the number of enrolment and verification samples, and the operating point selection on the maximum key size. We show that a trade-off exists between the privacy protection of the biometric system and its convenience for its users.

Evaluation of pliers' grip spans in the maximum gripping task and sub-maximum cutting task.

PubMed

Kim, Dae-Min; Kong, Yong-Ku

2016-12-01

A total of 25 males participated to investigate the effects of the grip spans of pliers on the total grip force, individual finger forces and muscle activities in the maximum gripping task and wire-cutting tasks. In the maximum gripping task, results showed that the 50-mm grip span had significantly higher total grip strength than the other grip spans. In the cutting task, the 50-mm grip span also showed significantly higher grip strength than the 65-mm and 80-mm grip spans, whereas the muscle activities showed a higher value at 80-mm grip span. The ratios of cutting force to maximum grip strength were also investigated. Ratios of 30.3%, 31.3% and 41.3% were obtained by grip spans of 50-mm, 65-mm, and 80-mm, respectively. Thus, the 50-mm grip span for pliers might be recommended to provide maximum exertion in gripping tasks, as well as lower maximum-cutting force ratios in the cutting tasks.

Microbiological Quality of Panicum maximum Grass Silage with Addition of Lactobacillus sp. as Starter

NASA Astrophysics Data System (ADS)

Sumarsih, S.; Sulistiyanto, B.; Utama, C. S.

2018-02-01

The aim of the research was to evaluate microbiological quality of Panicum maximum grass silage with addition Lactobacillus sp as starter. The completely randomized design was been used on this research with 4 treaments and 3 replications. The treatments were P0 ( Panicum maximum grass silage without addition Lactobacillus sp ), P1 ( Panicum maximum grass silage with 2% addition Lactobacillus sp), P2 (Panicum maximum grass silage with 4% addition Lactobacillus sp) and P3 (Panicum maximum grass silage with 6% addition Lactobacillus sp).The parameters were microbial populations of Panicum maximum grass silage (total lactic acid bacteria, total bacteria, total fungi, and Coliform bacteria. The data obtained were analyzed variance (ANOVA) and further tests performed Duncan’s Multiple Areas. The population of lactic acid bacteria was higher (P<0.05) and the total bacteria, fungi and Coliform were lower (P<0.05) with addition Lactobacillus sp. Microbiological quality of Panicum maximum grass silage with addition Lactobacillus sp was better than no addition Lactobacillus sp.

The Importance of Specific Workplace Environment Characteristics for Maximum Health and Performance: Healthcare Workers' Perspective.

PubMed

Sagha Zadeh, Rana; Shepley, Mardelle M; Owora, Arthur Hamie; Dannenbaum, Martha C; Waggener, Laurie T; Chung, Susan Sung Eun

2018-05-01

To examine the importance of specific workplace environment characteristics for maximum health and performance, assigned by healthcare employees, and how they relate to the nature of their work. A cross-sectional mixed-method study was conducted with content analysis and robust regression models to examine the relationship between workplace environment characteristics and perceived importance in promoting health and performance. Our findings suggest that perceptions of key environment characteristics that safeguard health and performance in healthcare workplaces may vary by employee sex, setting, and nature of healthcare work involved. Theme and model descriptions of the influence of these factors on participant perceptions are provided. Employee feedback on workplace characteristics that impact health and performance could be instrumental in determining the priorities of workplace design.

Maximum walking speeds obtained using treadmill and overground robot system in persons with post-stroke hemiplegia

PubMed Central

2012-01-01

Background Previous studies demonstrated that stroke survivors have a limited capacity to increase their walking speeds beyond their self-selected maximum walking speed (SMWS). The purpose of this study was to determine the capacity of stroke survivors to reach faster speeds than their SMWS while walking on a treadmill belt or while being pushed by a robotic system (i.e. “push mode”). Methods Eighteen chronic stroke survivors with hemiplegia were involved in the study. We calculated their self-selected comfortable walking speed (SCWS) and SMWS overground using a 5-meter walk test (5-MWT). Then, they were exposed to walking at increased speeds, on a treadmill and while in “push mode” in an overground robotic device, the KineAssist, until they were tested at a speed that they could not sustain without losing balance. We recorded the time and number of steps during each trial and calculated gait speed, average cadence and average step length. Results Maximum walking speed in the “push mode” was 13% higher than the maximum walking speed on the treadmill and both were higher (“push mode”: 61%; treadmill: 40%) than the maximum walking speed overground. Subjects achieved these faster speeds by initially increasing both step length and cadence and, once individuals stopped increasing their step length, by only increasing cadence. Conclusions With post-stroke hemiplegia, individuals are able to walk at faster speeds than their SMWS overground, when provided with a safe environment that provides external forces that requires them to attempt dynamic stability maintenance at higher gait speeds. Therefore, this study suggests the possibility that, given the appropriate conditions, people post-stroke can be trained at higher speeds than previously attempted. PMID:23057500

Determination of the maximum-depth to potential field sources by a maximum structural index method

NASA Astrophysics Data System (ADS)

Fedi, M.; Florio, G.

2013-01-01

A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.

Spatio-temporal observations of tertiary ozone maximum

NASA Astrophysics Data System (ADS)

Sofieva, V. F.; Kyrölä, E.; Verronen, P. T.; Seppälä, A.; Tamminen, J.; Marsh, D. R.; Smith, A. K.; Bertaux, J.-L.; Hauchecorne, A.; Dalaudier, F.; Fussen, D.; Vanhellemont, F.; Fanton D'Andon, O.; Barrot, G.; Guirlet, M.; Fehr, T.; Saavedra, L.

2009-03-01

We present spatio-temporal distributions of tertiary ozone maximum (TOM), based on GOMOS (Global Ozone Monitoring by Occultation of Stars) ozone measurements in 2002-2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at altitude ~72 km. Although the explanation for this phenomenon has been found recently - low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses - models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time obtaining spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere. The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory), TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model) and found that the specific features are reproduced satisfactorily by the model. Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

Performance analysis of the lineal model for estimating the maximum power of a HCPV module in different climate conditions

NASA Astrophysics Data System (ADS)

Fernández, Eduardo F.; Almonacid, Florencia; Sarmah, Nabin; Mallick, Tapas; Sanchez, Iñigo; Cuadra, Juan M.; Soria-Moya, Alberto; Pérez-Higueras, Pedro

2014-09-01

A model based on easily obtained atmospheric parameters and on a simple lineal mathematical expression has been developed at the Centre of Advanced Studies in Energy and Environment in southern Spain. The model predicts the maximum power of a HCPV module as a function of direct normal irradiance, air temperature and air mass. Presently, the proposed model has only been validated in southern Spain and its performance in locations with different atmospheric conditions still remains unknown. In order to address this issue, several HCPV modules have been measured in two different locations with different climate conditions than the south of Spain: the Environment and Sustainability Institute in southern UK and the National Renewable Energy Center in northern Spain. Results show that the model has an adequate match between actual and estimated data with a RMSE lower than 3.9% at locations with different climate conditions.

Obtaining of caffeine from Turkish tea fiber and stalk wastes.

PubMed

Gürü, M; Içen, H

2004-08-01

The aim of this study was to find a cheap method to obtain caffeine. Experiments were performed on fiber and stalk wastes of Turkish tea plants that had no economical value other than being used merely as low grade fuel and fodder. Tea stalks and fiber were obtained from tea factories. Parameters affecting caffeine extraction from tea wastes were determined to be, mixing rate, water/tea ratio, temperature, time and particle size. The maximum yields by dried mass from the tea fibers and stalks were 1.16% and 0.92%, respectively.

Maximum correntropy square-root cubature Kalman filter with application to SINS/GPS integrated systems.

PubMed

Liu, Xi; Qu, Hua; Zhao, Jihong; Yue, Pengcheng

2018-05-31

For a nonlinear system, the cubature Kalman filter (CKF) and its square-root version are useful methods to solve the state estimation problems, and both can obtain good performance in Gaussian noises. However, their performances often degrade significantly in the face of non-Gaussian noises, particularly when the measurements are contaminated by some heavy-tailed impulsive noises. By utilizing the maximum correntropy criterion (MCC) to improve the robust performance instead of traditional minimum mean square error (MMSE) criterion, a new square-root nonlinear filter is proposed in this study, named as the maximum correntropy square-root cubature Kalman filter (MCSCKF). The new filter not only retains the advantage of square-root cubature Kalman filter (SCKF), but also exhibits robust performance against heavy-tailed non-Gaussian noises. A judgment condition that avoids numerical problem is also given. The results of two illustrative examples, especially the SINS/GPS integrated systems, demonstrate the desirable performance of the proposed filter. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

The power and robustness of maximum LOD score statistics.

PubMed

Yoo, Y J; Mendell, N R

2008-07-01

The maximum LOD score statistic is extremely powerful for gene mapping when calculated using the correct genetic parameter value. When the mode of genetic transmission is unknown, the maximum of the LOD scores obtained using several genetic parameter values is reported. This latter statistic requires higher critical value than the maximum LOD score statistic calculated from a single genetic parameter value. In this paper, we compare the power of maximum LOD scores based on three fixed sets of genetic parameter values with the power of the LOD score obtained after maximizing over the entire range of genetic parameter values. We simulate family data under nine generating models. For generating models with non-zero phenocopy rates, LOD scores maximized over the entire range of genetic parameters yielded greater power than maximum LOD scores for fixed sets of parameter values with zero phenocopy rates. No maximum LOD score was consistently more powerful than the others for generating models with a zero phenocopy rate. The power loss of the LOD score maximized over the entire range of genetic parameters, relative to the maximum LOD score calculated using the correct genetic parameter value, appeared to be robust to the generating models.

25 CFR 170.142 - How can tribes obtain funds to perform highway safety projects?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 1 2013-04-01 2013-04-01 false How can tribes obtain funds to perform highway safety... WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and Eligibility Highway Safety Functions § 170.142 How can tribes obtain funds to perform highway safety projects? There are two...

25 CFR 170.142 - How can tribes obtain funds to perform highway safety projects?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 1 2014-04-01 2014-04-01 false How can tribes obtain funds to perform highway safety... WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and Eligibility Highway Safety Functions § 170.142 How can tribes obtain funds to perform highway safety projects? There are two...

25 CFR 170.142 - How can tribes obtain funds to perform highway safety projects?

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 1 2012-04-01 2011-04-01 true How can tribes obtain funds to perform highway safety... WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and Eligibility Highway Safety Functions § 170.142 How can tribes obtain funds to perform highway safety projects? There are two...

25 CFR 170.142 - How can tribes obtain funds to perform highway safety projects?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 1 2011-04-01 2011-04-01 false How can tribes obtain funds to perform highway safety... WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and Eligibility Highway Safety Functions § 170.142 How can tribes obtain funds to perform highway safety projects? There are two...

25 CFR 170.142 - How can tribes obtain funds to perform highway safety projects?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false How can tribes obtain funds to perform highway safety... WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and Eligibility Highway Safety Functions § 170.142 How can tribes obtain funds to perform highway safety projects? There are two...

Maximum angular accuracy of pulsed laser radar in photocounting limit.

PubMed

Elbaum, M; Diament, P; King, M; Edelson, W

1977-07-01

To estimate the angular position of targets with pulsed laser radars, their images may be sensed with a fourquadrant noncoherent detector and the image photocounting distribution processed to obtain the angular estimates. The limits imposed on the accuracy of angular estimation by signal and background radiation shot noise, dark current noise, and target cross-section fluctuations are calculated. Maximum likelihood estimates of angular positions are derived for optically rough and specular targets and their performances compared with theoretical lower bounds.

Shoe collar height effect on athletic performance, ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance.

PubMed

Lam, Gilbert Wing Kai; Park, Eun Jung; Lee, Ki-Kwang; Cheung, Jason Tak-Man

2015-01-01

Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting. Fifteen university basketball players performed maximum-effort side-step cutting to the left 45° direction or a straight ahead run in response to a random light signal. Seven successful cutting trials were collected for each condition. Athletic performance, ground reaction force, ankle kinematics and kinetics of both legs were analysed using paired t-tests. Results indicated that high-collar shoes resulted in less ankle inversion and external rotation during initial contact for the planting leg. The high-collar shoes also exhibited a smaller ankle range of motion in the sagittal and transverse planes for both legs, respectively. However, no collar effect was found for ankle moments and performance indicators including cutting performance time, ground contact time, propulsion ground reaction forces and impulses. These findings indicated that high-collar shoes altered ankle positioning and restricted ankle joint freedom movements in both legs, while no negative effect was found for athletic cutting performance.

Epidemiologic programs for computers and calculators. A microcomputer program for multiple logistic regression by unconditional and conditional maximum likelihood methods.

PubMed

Campos-Filho, N; Franco, E L

1989-02-01

A frequent procedure in matched case-control studies is to report results from the multivariate unmatched analyses if they do not differ substantially from the ones obtained after conditioning on the matching variables. Although conceptually simple, this rule requires that an extensive series of logistic regression models be evaluated by both the conditional and unconditional maximum likelihood methods. Most computer programs for logistic regression employ only one maximum likelihood method, which requires that the analyses be performed in separate steps. This paper describes a Pascal microcomputer (IBM PC) program that performs multiple logistic regression by both maximum likelihood estimation methods, which obviates the need for switching between programs to obtain relative risk estimates from both matched and unmatched analyses. The program calculates most standard statistics and allows factoring of categorical or continuous variables by two distinct methods of contrast. A built-in, descriptive statistics option allows the user to inspect the distribution of cases and controls across categories of any given variable.

Spatio-temporal observations of the tertiary ozone maximum

NASA Astrophysics Data System (ADS)

Sofieva, V. F.; Kyrölä, E.; Verronen, P. T.; Seppälä, A.; Tamminen, J.; Marsh, D. R.; Smith, A. K.; Bertaux, J.-L.; Hauchecorne, A.; Dalaudier, F.; Fussen, D.; Vanhellemont, F.; Fanton D'Andon, O.; Barrot, G.; Guirlet, M.; Fehr, T.; Saavedra, L.

2009-07-01

We present spatio-temporal distributions of the tertiary ozone maximum (TOM), based on GOMOS (Global Ozone Monitoring by Occultation of Stars) ozone measurements in 2002-2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at an altitude of ~72 km. Although the explanation for this phenomenon has been found recently - low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses - models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time to obtain spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere. The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory), TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of the tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model) and found that the specific features are reproduced satisfactorily by the model. Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

Methodological aspects of crossover and maximum fat-oxidation rate point determination.

PubMed

Michallet, A-S; Tonini, J; Regnier, J; Guinot, M; Favre-Juvin, A; Bricout, V; Halimi, S; Wuyam, B; Flore, P

2008-11-01

Indirect calorimetry during exercise provides two metabolic indices of substrate oxidation balance: the crossover point (COP) and maximum fat oxidation rate (LIPOXmax). We aimed to study the effects of the analytical device, protocol type and ventilatory response on variability of these indices, and the relationship with lactate and ventilation thresholds. After maximum exercise testing, 14 relatively fit subjects (aged 32+/-10 years; nine men, five women) performed three submaximum graded tests: one was based on a theoretical maximum power (tMAP) reference; and two were based on the true maximum aerobic power (MAP). Gas exchange was measured concomitantly using a Douglas bag (D) and an ergospirometer (E). All metabolic indices were interpretable only when obtained by the D reference method and MAP protocol. Bland and Altman analysis showed overestimation of both indices with E versus D. Despite no mean differences between COP and LIPOXmax whether tMAP or MAP was used, the individual data clearly showed disagreement between the two protocols. Ventilation explained 10-16% of the metabolic index variations. COP was correlated with ventilation (r=0.96, P<0.01) and the rate of increase in blood lactate (r=0.79, P<0.01), and LIPOXmax correlated with the ventilation threshold (r=0.95, P<0.01). This study shows that, in fit healthy subjects, the analytical device, reference used to build the protocol and ventilation responses affect metabolic indices. In this population, and particularly to obtain interpretable metabolic indices, we recommend a protocol based on the true MAP or one adapted to include the transition from fat to carbohydrate. The correlation between metabolic indices and lactate/ventilation thresholds suggests that shorter, classical maximum progressive exercise testing may be an alternative means of estimating these indices in relatively fit subjects. However, this needs to be confirmed in patients who have metabolic defects.

Dynamic Performance of Maximum Power Point Trackers in TEG Systems Under Rapidly Changing Temperature Conditions

NASA Astrophysics Data System (ADS)

Man, E. A.; Sera, D.; Mathe, L.; Schaltz, E.; Rosendahl, L.

2016-03-01

Characterization of thermoelectric generators (TEG) is widely discussed and equipment has been built that can perform such analysis. One method is often used to perform such characterization: constant temperature with variable thermal power input. Maximum power point tracking (MPPT) methods for TEG systems are mostly tested under steady-state conditions for different constant input temperatures. However, for most TEG applications, the input temperature gradient changes, exposing the MPPT to variable tracking conditions. An example is the exhaust pipe on hybrid vehicles, for which, because of the intermittent operation of the internal combustion engine, the TEG and its MPPT controller are exposed to a cyclic temperature profile. Furthermore, there are no guidelines on how fast the MPPT must be under such dynamic conditions. In the work discussed in this paper, temperature gradients for TEG integrated in several applications were evaluated; the results showed temperature variation up to 5°C/s for TEG systems. Electrical characterization of a calcium-manganese oxide TEG was performed at steady-state for different input temperatures and a maximum temperature of 401°C. By using electrical data from characterization of the oxide module, a solar array simulator was emulated to perform as a TEG. A trapezoidal temperature profile with different gradients was used on the TEG simulator to evaluate the dynamic MPPT efficiency. It is known that the perturb and observe (P&O) algorithm may have difficulty accurately tracking under rapidly changing conditions. To solve this problem, a compromise must be found between the magnitude of the increment and the sampling frequency of the control algorithm. The standard P&O performance was evaluated experimentally by using different temperature gradients for different MPPT sampling frequencies, and efficiency values are provided for all cases. The results showed that a tracking speed of 2.5 Hz can be successfully implemented on a TEG

Inverting ion images without Abel inversion: maximum entropy reconstruction of velocity maps.

PubMed

Dick, Bernhard

2014-01-14

A new method for the reconstruction of velocity maps from ion images is presented, which is based on the maximum entropy concept. In contrast to other methods used for Abel inversion the new method never applies an inversion or smoothing to the data. Instead, it iteratively finds the map which is the most likely cause for the observed data, using the correct likelihood criterion for data sampled from a Poissonian distribution. The entropy criterion minimizes the information content in this map, which hence contains no information for which there is no evidence in the data. Two implementations are proposed, and their performance is demonstrated with simulated and experimental data: Maximum Entropy Velocity Image Reconstruction (MEVIR) obtains a two-dimensional slice through the velocity distribution and can be compared directly to Abel inversion. Maximum Entropy Velocity Legendre Reconstruction (MEVELER) finds one-dimensional distribution functions Q(l)(v) in an expansion of the velocity distribution in Legendre polynomials P((cos θ) for the angular dependence. Both MEVIR and MEVELER can be used for the analysis of ion images with intensities as low as 0.01 counts per pixel, with MEVELER performing significantly better than MEVIR for images with low intensity. Both methods perform better than pBASEX, in particular for images with less than one average count per pixel.

The relative performance obtained with several methods of control of an overcompressed engine using gasoline

NASA Technical Reports Server (NTRS)

Gardiner, Arthur W; Whedon, William E

1928-01-01

This report presents some results obtained during an investigation to determine the relative characteristics for several methods of control of an overcompressed engine using gasoline and operating under sea-level conditions. For this work, a special single cylinder test engine, 5-inch bore by 7-inch stroke, and designed for ready adjustment of compression ratio, valve timing and valve lift while running, was used. This engine has been fully described in NACA-TR-250. Tests were made at an engine speed of 1,400 R. P. M. for compression ratios ranging from 4.0 to 7.6. The air-fuel ratios were on the rich side of the chemically correct mixture and were approximately those giving maximum power. When using plain domestic gasoline, detonation was controlled to a constant, predetermined amount (audible), such as would be permissible for continuous operation, by (a) throttling the carburetor, (b) maintaining full throttle but greatly retarding the ignition, and (c) varying the timing of the inlet valve to reduce the effective compression ratio. From the results of the tests, it may be concluded that method (b) gives the best all-round performance and, being easily employed in service, appears to be the most practicable method for controlling an overcompressed engine using gasoline at low altitudes.

Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

NASA Astrophysics Data System (ADS)

Hall, Alex; Taylor, Andy

2017-06-01

We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

Performance of Axial-Flow Supersonic Compressor of XJ55-FF-1 Turbojet Engine. III; Over-All Performance of Compressor

NASA Technical Reports Server (NTRS)

Hartmann, Melvin J.; Tysl, Edward R.

1949-01-01

An investigation was conducted to determine the performance characteristics of the rotor and inlet guide vanes used in the axial-flow supersonic compressor of the XJ55-FF-1 turbojet engine. Outlet stators used in the engine were omitted to facilitate study of the supersonic rotor. The extent of the deviation from design performance indicates that the design-shock configuration was not obtained. A maximum pressure ratio of 2.26 was obtained at an equivalent tip speed of 1614 feet per second and an adiabatic efficiency of 0.61. The maximum efficiency obtained was 0.79 at an equivalent tip speed of 801 feet per second and a pressure ratio of 1.29. The performance obtained was considerably below design performance. The effective aerodynamic forces encountered appeared to be large enough to cause considerable damage to the thin aluminum leading edges of the rotor blades.

Objects of Maximum Electromagnetic Chirality

NASA Astrophysics Data System (ADS)

Fernandez-Corbaton, Ivan; Fruhnert, Martin; Rockstuhl, Carsten

2016-07-01

We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. Reciprocal objects attain the upper bound if and only if they are transparent for all the fields of one polarization handedness (helicity). Additionally, electromagnetic duality symmetry, i.e., helicity preservation upon interaction, turns out to be a necessary condition for reciprocal objects to attain the upper bound. We use these results to provide requirements for the design of such extremal objects. The requirements can be formulated as constraints on the polarizability tensors for dipolar objects or on the material constitutive relations for continuous media. We also outline two applications for objects of maximum electromagnetic chirality: a twofold resonantly enhanced and background-free circular dichroism measurement setup, and angle-independent helicity filtering glasses. Finally, we use the theoretically obtained requirements to guide the design of a specific structure, which we then analyze numerically and discuss its performance with respect to maximal electromagnetic chirality.

Maximum Bite Force Analysis in Different Age Groups

PubMed Central

Takaki, Patricia; Vieira, Marilena; Bommarito, Silvana

2014-01-01

Introduction Maximum bite force (MBF) is the maximum force performed by the subject on the fragmentation of food, directly related with the mastication and determined by many factors. Objective Analyze the MBF of subjects according to age groups. Methods One hundred individuals from the city of São Paulo were equally divided according to age groups and gender. Each individual submitted to a myotherapy evaluation composed of anthropometric measurements of height and weight to obtain body mass index (BMI), using a tape and a digital scale (Magna, G-life, São Paulo), and a dental condition and maximum bite force evaluation, using a digital dynamometer model DDK/M (Kratos, São Paulo, Brazil), on Newton scale. The dental and bite force evaluations were monitored by a professional from the area. Analysis of variance was used with MBF as a dependent variable, age group and gender as random factors, and BMI as a control variable. Results Till the end of adolescence, it was possible to observe a decrease in MBF in both sexes, with the male force greater than the female force. In young adults, the female force became greater the males, then decreased in adulthood. There was no correlation between MBF and BMI. Conclusion There are MBF variations that characterizes the human development stages, according to age groups. PMID:25992105

Timing of maximum glacial extent and deglaciation from HualcaHualca volcano (southern Peru), obtained with cosmogenic 36Cl.

NASA Astrophysics Data System (ADS)

Alcalá, Jesus; Palacios, David; Vazquez, Lorenzo; Juan Zamorano, Jose

2015-04-01

Andean glacial deposits are key records of climate fluctuations in the southern hemisphere. During the last decades, in situ cosmogenic nuclides have provided fresh and significant dates to determine past glacier behavior in this region. But still there are many important discrepancies such as the impact of Last Glacial Maximum or the influence of Late Glacial climatic events on glacial mass balances. Furthermore, glacial chronologies from many sites are still missing, such as HualcaHualca (15° 43' S; 71° 52' W; 6,025 masl), a high volcano of the Peruvian Andes located 70 km northwest of Arequipa. The goal of this study is to establish the age of the Maximum Glacier Extent (MGE) and deglaciation at HualcaHualca volcano. To achieve this objetive, we focused in four valleys (Huayuray, Pujro Huayjo, Mollebaya and Mucurca) characterized by a well-preserved sequence of moraines and roches moutonnées. The method is based on geomorphological analysis supported by cosmogenic 36Cl surface exposure dating. 36Cl ages have been estimated with the CHLOE calculator and were compared with other central Andean glacial chronologies as well as paleoclimatological proxies. In Huayuray valley, exposure ages indicates that MGE occurred ~ 18 - 16 ka. Later, the ice mass gradually retreated but this process was interrupted by at least two readvances; the last one has been dated at ~ 12 ka. In the other hand, 36Cl result reflects a MGE age of ~ 13 ka in Mollebaya valley. Also, two samples obtained in Pujro-Huayjo and Mucurca valleys associated with MGE have an exposure age of 10-9 ka, but likely are moraine boulders affected by exhumation or erosion processes. Deglaciation in HualcaHualca volcano began abruptly ~ 11.5 ka ago according to a 36Cl age from a polished and striated bedrock in Pujro Huayjo valley, presumably as a result of reduced precipitation as well as a global increase of temperatures. The glacier evolution at HualcaHualca volcano presents a high correlation with

ASSESSMENT OF MAXIMUM SUSTAINABLE SWIMMING PERFORMANCE IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

PubMed

Wilson; Egginton

1994-07-01

Levels of swimming activity in fishes have been divided into three categories on the basis of the time a given speed can be maintained before the onset of fatigue (Beamish, 1978): sustained (more than 200 min), prolonged (20 s to 200 min) and burst swimming (less than 20 s). The locomotory capacity of a given species reflects both its lifestyle and its body form, although definitions of performance may vary. It is generally accepted that only the aerobic ('red') muscle fibres should be active at truly sustainable swimming speeds, i.e. at speeds that can be maintained indefinitely without fatigue. However, the standard laboratory method of evaluating the maximum sustainable swimming speed (Ucrit; Brett, 1964) almost certainly entails the recruitment of at least some of the rapidly fatigable fast glycolytic ('white') fibres at sub-critical speeds and undoubtedly complicates the evaluation of maximal cardiovascular performance. It would therefore be useful to have an objective and reproducible measure of truly sustainable performance that, by definition, relies solely on aerobic muscle activity. Electromyography (EMG) has been used to examine the pattern of white muscle recruitment following thermal acclimation in striped bass, Morine saxatilis (Sisson and Sidell, 1987). We wished to incorporate this method into a study of the acclimatory responses to chronic changes in environmental temperature of the cardiovascular and locomotory systems in rainbow trout (Wilson and Egginton, 1992). The present communication presents results on the cardiovascular performance and blood chemistry, at rest and during maximal aerobic exercise, of rainbow trout acclimated to 11 °C, as a validation of the methodology currently in use with fish acclimated to seasonal temperature extremes (Taylor et al. 1992). Different acclimation temperatures are known to produce compensatory changes in the relative proportions of red and white muscle mass (Sidell and Moerland, 1989). The aim of these

An Investigation Into the Relationship Between Maximum Isometric Strength and Vertical Jump Performance.

PubMed

Thomas, Christopher; Jones, Paul A; Rothwell, James; Chiang, Chieh Y; Comfort, Paul

2015-08-01

Research has demonstrated a clear relationship between dynamic strength and vertical jump (VJ) performance; however, the relationship of isometric strength and VJ performance has been studied less extensively. The aim of this study was to determine the relationship between isometric strength and performance during the squat jump (SJ) and countermovement jump (CMJ). Twenty-two male collegiate athletes (mean ± SD; age = 21.3 ± 2.9 years; height = 175.63 ± 8.23 cm; body mass = 78.06 ± 10.77 kg) performed isometric midthigh pulls (IMTPs) to assess isometric peak force (IPF), maximum rate of force development, and impulse (IMP) (I100, I200, and I300). Force-time data, collected during the VJs, were used to calculate peak velocity, peak force (PF), peak power (PP), and jump height. Absolute IMTP measures of IMP showed the strongest correlations with VJ PF (r = 0.43-0.64; p ≤ 0.05) and VJ PP (r = 0.38-0.60; p ≤ 0.05). No statistical difference was observed in CMJ height (0.33 ± 0.05 m vs. 0.36 ± 0.05 m; p = 0.19; ES = -0.29) and SJ height performance (0.29 ± 0.06 m vs. 0.33 ± 0.05 m; p = 0.14; ES = -0.34) when comparing stronger to weaker athletes. The results of this study illustrate that absolute IPF and IMP are related to VJ PF and PP but not VJ height. Because stronger athletes did not jump higher than weaker athletes, dynamic strength tests may be more practical methods of assessing the relationships between relative strength levels and dynamic performance in collegiate athletes.

Bayesian Maximum Entropy Integration of Ozone Observations and Model Predictions: A National Application.

PubMed

Xu, Yadong; Serre, Marc L; Reyes, Jeanette; Vizuete, William

2016-04-19

To improve ozone exposure estimates for ambient concentrations at a national scale, we introduce our novel Regionalized Air Quality Model Performance (RAMP) approach to integrate chemical transport model (CTM) predictions with the available ozone observations using the Bayesian Maximum Entropy (BME) framework. The framework models the nonlinear and nonhomoscedastic relation between air pollution observations and CTM predictions and for the first time accounts for variability in CTM model performance. A validation analysis using only noncollocated data outside of a validation radius rv was performed and the R(2) between observations and re-estimated values for two daily metrics, the daily maximum 8-h average (DM8A) and the daily 24-h average (D24A) ozone concentrations, were obtained with the OBS scenario using ozone observations only in contrast with the RAMP and a Constant Air Quality Model Performance (CAMP) scenarios. We show that, by accounting for the spatial and temporal variability in model performance, our novel RAMP approach is able to extract more information in terms of R(2) increase percentage, with over 12 times for the DM8A and over 3.5 times for the D24A ozone concentrations, from CTM predictions than the CAMP approach assuming that model performance does not change across space and time.

A maximum entropy reconstruction technique for tomographic particle image velocimetry

NASA Astrophysics Data System (ADS)

Bilsky, A. V.; Lozhkin, V. A.; Markovich, D. M.; Tokarev, M. P.

2013-04-01

This paper studies a novel approach for reducing tomographic PIV computational complexity. The proposed approach is an algebraic reconstruction technique, termed MENT (maximum entropy). This technique computes the three-dimensional light intensity distribution several times faster than SMART, using at least ten times less memory. Additionally, the reconstruction quality remains nearly the same as with SMART. This paper presents the theoretical computation performance comparison for MENT, SMART and MART, followed by validation using synthetic particle images. Both the theoretical assessment and validation of synthetic images demonstrate significant computational time reduction. The data processing accuracy of MENT was compared to that of SMART in a slot jet experiment. A comparison of the average velocity profiles shows a high level of agreement between the results obtained with MENT and those obtained with SMART.

Performance and separation occurrence of binary probit regression estimator using maximum likelihood method and Firths approach under different sample size

NASA Astrophysics Data System (ADS)

Lusiana, Evellin Dewi

2017-12-01

The parameters of binary probit regression model are commonly estimated by using Maximum Likelihood Estimation (MLE) method. However, MLE method has limitation if the binary data contains separation. Separation is the condition where there are one or several independent variables that exactly grouped the categories in binary response. It will result the estimators of MLE method become non-convergent, so that they cannot be used in modeling. One of the effort to resolve the separation is using Firths approach instead. This research has two aims. First, to identify the chance of separation occurrence in binary probit regression model between MLE method and Firths approach. Second, to compare the performance of binary probit regression model estimator that obtained by MLE method and Firths approach using RMSE criteria. Those are performed using simulation method and under different sample size. The results showed that the chance of separation occurrence in MLE method for small sample size is higher than Firths approach. On the other hand, for larger sample size, the probability decreased and relatively identic between MLE method and Firths approach. Meanwhile, Firths estimators have smaller RMSE than MLEs especially for smaller sample sizes. But for larger sample sizes, the RMSEs are not much different. It means that Firths estimators outperformed MLE estimator.

Convex Accelerated Maximum Entropy Reconstruction

PubMed Central

Worley, Bradley

2016-01-01

Maximum entropy (MaxEnt) spectral reconstruction methods provide a powerful framework for spectral estimation of nonuniformly sampled datasets. Many methods exist within this framework, usually defined based on the magnitude of a Lagrange multiplier in the MaxEnt objective function. An algorithm is presented here that utilizes accelerated first-order convex optimization techniques to rapidly and reliably reconstruct nonuniformly sampled NMR datasets using the principle of maximum entropy. This algorithm – called CAMERA for Convex Accelerated Maximum Entropy Reconstruction Algorithm – is a new approach to spectral reconstruction that exhibits fast, tunable convergence in both constant-aim and constant-lambda modes. A high-performance, open source NMR data processing tool is described that implements CAMERA, and brief comparisons to existing reconstruction methods are made on several example spectra. PMID:26894476

Prediction of effects of wing contour modifications on low-speed maximum lift and transonic performance for the EA-6B aircraft

NASA Technical Reports Server (NTRS)

Allison, Dennis O.; Waggoner, E. G.

1990-01-01

Computational predictions of the effects of wing contour modifications on maximum lift and transonic performance were made and verified against low speed and transonic wind tunnel data. This effort was part of a program to improve the maneuvering capability of the EA-6B electronics countermeasures aircraft, which evolved from the A-6 attack aircraft. The predictions were based on results from three computer codes which all include viscous effects: MCARF, a 2-D subsonic panel code; TAWFIVE, a transonic full potential code; and WBPPW, a transonic small disturbance potential flow code. The modifications were previously designed with the aid of these and other codes. The wing modifications consists of contour changes to the leading edge slats and trailing edge flaps and were designed for increased maximum lift with minimum effect on transonic performance. The prediction of the effects of the modifications are presented, with emphasis on verification through comparisons with wind tunnel data from the National Transonic Facility. Attention is focused on increments in low speed maximum lift and increments in transonic lift, pitching moment, and drag resulting from the contour modifications.

Whole-remnant and maximum-voxel SPECT/CT dosimetry in {sup 131}I-NaI treatments of differentiated thyroid cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mínguez, Pablo, E-mail: pablo.minguezgabina@osakid

Purpose: To investigate the possible differences between SPECT/CT based whole-remnant and maximum-voxel dosimetry in patients receiving radio-iodine ablation treatment of differentiated thyroid cancer (DTC). Methods: Eighteen DTC patients were administered 1.11 GBq of {sup 131}I-NaI after near-total thyroidectomy and rhTSH stimulation. Two patients had two remnants, so in total dosimetry was performed for 20 sites. Three SPECT/CT scans were performed for each patient at 1, 2, and 3–7 days after administration. The activity, the remnant mass, and the maximum-voxel activity were determined from these images and from a recovery-coefficient curve derived from experimental phantom measurements. The cumulated activity was estimatedmore » using trapezoidal-exponential integration. Finally, the absorbed dose was calculated using S-values for unit-density spheres in whole-remnant dosimetry and S-values for voxels in maximum-voxel dosimetry. Results: The mean absorbed dose obtained from whole-remnant dosimetry was 40 Gy (range 2–176 Gy) and from maximum-voxel dosimetry 34 Gy (range 2–145 Gy). For any given patient, the activity concentrations for each of the three time-points were approximately the same for the two methods. The effective half-lives varied (R = 0.865), mainly due to discrepancies in estimation of the longer effective half-lives. On average, absorbed doses obtained from whole-remnant dosimetry were 1.2 ± 0.2 (1 SD) higher than for maximum-voxel dosimetry, mainly due to differences in the S-values. The method-related differences were however small in comparison to the wide range of absorbed doses obtained in patients. Conclusions: Simple and consistent procedures for SPECT/CT based whole-volume and maximum-voxel dosimetry have been described, both based on experimentally determined recovery coefficients. Generally the results from the two approaches are consistent, although there is a small, systematic difference in the absorbed dose due to differences

Optimizing the maximum reported cluster size in the spatial scan statistic for ordinal data.

PubMed

Kim, Sehwi; Jung, Inkyung

2017-01-01

The spatial scan statistic is an important tool for spatial cluster detection. There have been numerous studies on scanning window shapes. However, little research has been done on the maximum scanning window size or maximum reported cluster size. Recently, Han et al. proposed to use the Gini coefficient to optimize the maximum reported cluster size. However, the method has been developed and evaluated only for the Poisson model. We adopt the Gini coefficient to be applicable to the spatial scan statistic for ordinal data to determine the optimal maximum reported cluster size. Through a simulation study and application to a real data example, we evaluate the performance of the proposed approach. With some sophisticated modification, the Gini coefficient can be effectively employed for the ordinal model. The Gini coefficient most often picked the optimal maximum reported cluster sizes that were the same as or smaller than the true cluster sizes with very high accuracy. It seems that we can obtain a more refined collection of clusters by using the Gini coefficient. The Gini coefficient developed specifically for the ordinal model can be useful for optimizing the maximum reported cluster size for ordinal data and helpful for properly and informatively discovering cluster patterns.

Optimizing the maximum reported cluster size in the spatial scan statistic for ordinal data

PubMed Central

Kim, Sehwi

2017-01-01

The spatial scan statistic is an important tool for spatial cluster detection. There have been numerous studies on scanning window shapes. However, little research has been done on the maximum scanning window size or maximum reported cluster size. Recently, Han et al. proposed to use the Gini coefficient to optimize the maximum reported cluster size. However, the method has been developed and evaluated only for the Poisson model. We adopt the Gini coefficient to be applicable to the spatial scan statistic for ordinal data to determine the optimal maximum reported cluster size. Through a simulation study and application to a real data example, we evaluate the performance of the proposed approach. With some sophisticated modification, the Gini coefficient can be effectively employed for the ordinal model. The Gini coefficient most often picked the optimal maximum reported cluster sizes that were the same as or smaller than the true cluster sizes with very high accuracy. It seems that we can obtain a more refined collection of clusters by using the Gini coefficient. The Gini coefficient developed specifically for the ordinal model can be useful for optimizing the maximum reported cluster size for ordinal data and helpful for properly and informatively discovering cluster patterns. PMID:28753674

Coefficient of performance at maximum figure of merit and its bounds for low-dissipation Carnot-like refrigerators.

PubMed

Wang, Yang; Li, Mingxing; Tu, Z C; Hernández, A Calvo; Roco, J M M

2012-07-01

The figure of merit for refrigerators performing finite-time Carnot-like cycles between two reservoirs at temperature T(h) and T(c) (performance at maximum figure of merit is bounded between 0 and (sqrt[9+8ε(c)] - 3)/2 for the low-dissipation refrigerators, where ε(c) = T(c)/(T(h) - T(c)) is the Carnot coefficient of performance for reversible refrigerators. These bounds can be reached for extremely asymmetric low-dissipation cases when the ratio between the dissipation constants of the processes in contact with the cold and hot reservoirs approaches to zero or infinity, respectively. The observed coefficients of performance for real refrigerators are located in the region between the lower and upper bounds, which is in good agreement with our theoretical estimation.

Effectiveness of Resistance Circuit-Based Training for Maximum Oxygen Uptake and Upper-Body One-Repetition Maximum Improvements: A Systematic Review and Meta-Analysis.

PubMed

Muñoz-Martínez, Francisco Antonio; Rubio-Arias, Jacobo Á; Ramos-Campo, Domingo Jesús; Alcaraz, Pedro E

2017-12-01

It is well known that concurrent increases in both maximal strength and aerobic capacity are associated with improvements in sports performance as well as overall health. One of the most popular training methods used for achieving these objectives is resistance circuit-based training. The objective of the present systematic review with a meta-analysis was to evaluate published studies that have investigated the effects of resistance circuit-based training on maximum oxygen uptake and one-repetition maximum of the upper-body strength (bench press exercise) in healthy adults. The following electronic databases were searched from January to June 2016: PubMed, Web of Science and Cochrane. Studies were included if they met the following criteria: (1) examined healthy adults aged between 18 and 65 years; (2) met the characteristics of resistance circuit-based training; and (3) analysed the outcome variables of maximum oxygen uptake using a gas analyser and/or one-repetition maximum bench press. Of the 100 articles found from the database search and after all duplicates were removed, eight articles were analysed for maximum oxygen uptake. Of 118 healthy adults who performed resistance circuit-based training, maximum oxygen uptake was evaluated before and after the training programme. Additionally, from the 308 articles found for one-repetition maximum, eight articles were analysed. The bench press one-repetition maximum load, of 237 healthy adults who performed resistance circuit-based training, was evaluated before and after the training programme. Significant increases in maximum oxygen uptake and one-repetition maximum bench press were observed following resistance circuit-based training. Additionally, significant differences in maximum oxygen uptake and one-repetition maximum bench press were found between the resistance circuit-based training and control groups. The meta-analysis showed that resistance circuit-based training, independent of the protocol used in the

On the Pontryagin maximum principle for systems with delays. Economic applications

NASA Astrophysics Data System (ADS)

Kim, A. V.; Kormyshev, V. M.; Kwon, O. B.; Mukhametshin, E. R.

2017-11-01

The Pontryagin maximum principle [6] is the key stone of finite-dimensional optimal control theory [1, 2, 5]. So beginning with opening the maximum principle it was important to extend the maximum principle on various classes of dynamical systems. In t he paper we consider some aspects of application of i-smooth analysis [3, 4] in the theory of the Pontryagin maximum principle [6] for systems with delays, obtained results can be applied by elaborating optimal program controls in economic models with delays.

Effect of the flexibility training performed immediately before resistance training on muscle hypertrophy, maximum strength and flexibility.

PubMed

Junior, Roberto Moriggi; Berton, Ricardo; de Souza, Thiago Mattos Frota; Chacon-Mikahil, Mara Patrícia Traina; Cavaglieri, Cláudia Regina

2017-04-01

It has been suggested that flexibility training may reduce the total volume of training during resistance trainings. The purpose of this study was to compare the effect of flexibility training immediately before resistance training (FLEX-RT) versus resistance training without flexibility training (RT) on maximum strength and the vastus lateralis muscle cross-sectional area (CSA). Participants had each leg assigned to RT or FLEX-RT. Both groups performed four sets of leg extensions to voluntary failure of 80% of one repetition maximum (1RM); however, FLEX-RT performed two sets of 25 s of static stretching before resistance training. Number of repetitions and total volume were calculated during weeks 1-5 and 6-10. Vastus lateralis muscle CSA, 1RM, and flexibility were assessed at baseline and after 10 weeks. The number of repetitions and total training volume were greater for RT than FLEX-RT for weeks 1-5 and 6-10. Regarding the vastus lateralis muscle CSA, a main time effect was observed, however, greater change was observed for RT than FLEX-RT (12.7 and 7.4%, respectively). A main time effect for 1RM was also observed with similar changes for RT and FLEX-RT (12.7 and 12.9%, respectively). Flexibility was increased pre- to post-training for FLEX-RT with greater change for FLEX-RT (10.1%) than RT (2.1%). These results show that performing flexibility training immediately before resistance training can contribute to a lower number of repetitions, total volume, and muscle hypertrophy.

A Maximum Likelihood Approach to Functional Mapping of Longitudinal Binary Traits

PubMed Central

Wang, Chenguang; Li, Hongying; Wang, Zhong; Wang, Yaqun; Wang, Ningtao; Wang, Zuoheng; Wu, Rongling

2013-01-01

Despite their importance in biology and biomedicine, genetic mapping of binary traits that change over time has not been well explored. In this article, we develop a statistical model for mapping quantitative trait loci (QTLs) that govern longitudinal responses of binary traits. The model is constructed within the maximum likelihood framework by which the association between binary responses is modeled in terms of conditional log odds-ratios. With this parameterization, the maximum likelihood estimates (MLEs) of marginal mean parameters are robust to the misspecification of time dependence. We implement an iterative procedures to obtain the MLEs of QTL genotype-specific parameters that define longitudinal binary responses. The usefulness of the model was validated by analyzing a real example in rice. Simulation studies were performed to investigate the statistical properties of the model, showing that the model has power to identify and map specific QTLs responsible for the temporal pattern of binary traits. PMID:23183762

Effect of Water-Alcohol Injection and Maximum Economy Spark Advance on Knock-Limited Performance and Fuel Economy of a Large Air-Cooled Cylinder

NASA Technical Reports Server (NTRS)

Heinicke, Orville H.; Vandeman, Jack E.

1945-01-01

An investigation was conducted to determine the effect of a coolant solution of 25 percent ethyl alcohol, 25 percent methyl alcohol, and 50 percent water by volume and maximum-economy spark advance on knock-limited performance and fuel economy of a large air-cooled cylinder. The knock-limited performance of the cylinder at engine speeds of 2100 and 2500 rpm was determined for coolant-fuel ratios of 0.0, 0.2, and 0.4. The effect of water-alcohol injection on fuel economy was determined in constant charge-air flow tests. The tests were conducted at a spark advance of 20 deg B.T.C. and maximum-economy spark advance.

The ultrasound-enhanced bioscouring performance of four polygalacturonase enzymes obtained from rhizopus oryzae

USDA-ARS?s Scientific Manuscript database

An analytical and statistical method has been developed to measure the ultrasound-enhanced bioscouring performance of milligram quantities of endo- and exo-polygalacturonase enzymes obtained from Rhizopus oryzae fungi. UV-Vis spectrophotometric data and a general linear mixed models procedure indic...

From Maximum Entropy Models to Non-Stationarity and Irreversibility

NASA Astrophysics Data System (ADS)

Cofre, Rodrigo; Cessac, Bruno; Maldonado, Cesar

The maximum entropy distribution can be obtained from a variational principle. This is important as a matter of principle and for the purpose of finding approximate solutions. One can exploit this fact to obtain relevant information about the underlying stochastic process. We report here in recent progress in three aspects to this approach.1- Biological systems are expected to show some degree of irreversibility in time. Based on the transfer matrix technique to find the spatio-temporal maximum entropy distribution, we build a framework to quantify the degree of irreversibility of any maximum entropy distribution.2- The maximum entropy solution is characterized by a functional called Gibbs free energy (solution of the variational principle). The Legendre transformation of this functional is the rate function, which controls the speed of convergence of empirical averages to their ergodic mean. We show how the correct description of this functional is determinant for a more rigorous characterization of first and higher order phase transitions.3- We assess the impact of a weak time-dependent external stimulus on the collective statistics of spiking neuronal networks. We show how to evaluate this impact on any higher order spatio-temporal correlation. RC supported by ERC advanced Grant ``Bridges'', BC: KEOPS ANR-CONICYT, Renvision and CM: CONICYT-FONDECYT No. 3140572.

The maximum economic depth of groundwater abstraction for irrigation

NASA Astrophysics Data System (ADS)

Bierkens, M. F.; Van Beek, L. P.; de Graaf, I. E. M.; Gleeson, T. P.

2017-12-01

Over recent decades, groundwater has become increasingly important for agriculture. Irrigation accounts for 40% of the global food production and its importance is expected to grow further in the near future. Already, about 70% of the globally abstracted water is used for irrigation, and nearly half of that is pumped groundwater. In many irrigated areas where groundwater is the primary source of irrigation water, groundwater abstraction is larger than recharge and we see massive groundwater head decline in these areas. An important question then is: to what maximum depth can groundwater be pumped for it to be still economically recoverable? The objective of this study is therefore to create a global map of the maximum depth of economically recoverable groundwater when used for irrigation. The maximum economic depth is the maximum depth at which revenues are still larger than pumping costs or the maximum depth at which initial investments become too large compared to yearly revenues. To this end we set up a simple economic model where costs of well drilling and the energy costs of pumping, which are a function of well depth and static head depth respectively, are compared with the revenues obtained for the irrigated crops. Parameters for the cost sub-model are obtained from several US-based studies and applied to other countries based on GDP/capita as an index of labour costs. The revenue sub-model is based on gross irrigation water demand calculated with a global hydrological and water resources model, areal coverage of crop types from MIRCA2000 and FAO-based statistics on crop yield and market price. We applied our method to irrigated areas in the world overlying productive aquifers. Estimated maximum economic depths range between 50 and 500 m. Most important factors explaining the maximum economic depth are the dominant crop type in the area and whether or not initial investments in well infrastructure are limiting. In subsequent research, our estimates of

Assessing the performance of winter footwear using a new maximum achievable incline method.

PubMed

Hsu, Jennifer; Li, Yue; Dutta, Tilak; Fernie, Geoff

2015-09-01

More informative tests of winter footwear performance are required in order to identify footwear that will prevent injurious slips and falls on icy conditions. In this study, eight participants tested four styles of winter boots on smooth wet ice. The surface was progressively tilted to create increasing longitudinal and cross-slopes until participants could no longer continue standing or walking. Maximum achievable incline angles provided consistent measures of footwear slip resistance and demonstrated better resolution than mechanical tests. One footwear outsole material and tread combination outperformed the others on wet ice allowing participants to successfully walk on steep longitudinal slopes of 17.5° ± 1.9° (mean ± SD). By further exploiting the methodology to include additional surfaces and contaminants, such tests could be used to optimize tread designs and materials that are ideal for reducing the risk of slips and falls. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Analysis of force profile during a maximum voluntary isometric contraction task.

PubMed

Househam, Elizabeth; McAuley, John; Charles, Thompson; Lightfoot, Timothy; Swash, Michael

2004-03-01

This study analyses maximum voluntary isometric contraction (MVIC) and its measurement by recording the force profile during maximal-effort, 7-s hand-grip contractions. Six healthy subjects each performed three trials repeated at short intervals to study variation from fatigue. These three trials were performed during three separate sessions at daily intervals to look at random variation. A pattern of force development during a trial was identified. An initiation phase, with or without an initiation peak, was followed by a maintenance phase, sometimes with secondary pulses and an underlying decline in force. Of these three MVIC parameters, maximum force during the maintenance phase showed less random variability compared to intertrial fatigue variability than did maximum force during the initiation phase or absolute maximum force. Analysis of MVIC as a task, rather than a single, maximal value reveals deeper levels of motor control in its generation. Thus, force parameters other than the absolute maximum force may be better suited to quantification of muscle performance in health and disease.

The Maximum Density of Water.

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

1985-01-01

Discusses a series of experiments performed by Thomas Hope in 1805 which show the temperature at which water has its maximum density. Early data cast into a modern form as well as guidelines and recent data collected from the author provide background for duplicating Hope's experiments in the classroom. (JN)

Forming Student Online Teams for Maximum Performance

ERIC Educational Resources Information Center

Olson, Joel D.; Ringhand, Darlene G.; Kalinski, Ray C.; Ziegler, James G.

2015-01-01

What is the best way to assign graduate business students to online team-based projects? Team assignments are frequently made on the basis of alphabet, time zones or previous performance. This study reviews personality as an indicator of student online team performance. The personality assessment IDE (Insights Discovery Evaluator) was administered…

Maximum-likelihood soft-decision decoding of block codes using the A* algorithm

NASA Technical Reports Server (NTRS)

Ekroot, L.; Dolinar, S.

1994-01-01

The A* algorithm finds the path in a finite depth binary tree that optimizes a function. Here, it is applied to maximum-likelihood soft-decision decoding of block codes where the function optimized over the codewords is the likelihood function of the received sequence given each codeword. The algorithm considers codewords one bit at a time, making use of the most reliable received symbols first and pursuing only the partially expanded codewords that might be maximally likely. A version of the A* algorithm for maximum-likelihood decoding of block codes has been implemented for block codes up to 64 bits in length. The efficiency of this algorithm makes simulations of codes up to length 64 feasible. This article details the implementation currently in use, compares the decoding complexity with that of exhaustive search and Viterbi decoding algorithms, and presents performance curves obtained with this implementation of the A* algorithm for several codes.

A Maximum-Likelihood Approach to Force-Field Calibration.

PubMed

Zaborowski, Bartłomiej; Jagieła, Dawid; Czaplewski, Cezary; Hałabis, Anna; Lewandowska, Agnieszka; Żmudzińska, Wioletta; Ołdziej, Stanisław; Karczyńska, Agnieszka; Omieczynski, Christian; Wirecki, Tomasz; Liwo, Adam

2015-09-28

A new approach to the calibration of the force fields is proposed, in which the force-field parameters are obtained by maximum-likelihood fitting of the calculated conformational ensembles to the experimental ensembles of training system(s). The maximum-likelihood function is composed of logarithms of the Boltzmann probabilities of the experimental conformations, calculated with the current energy function. Because the theoretical distribution is given in the form of the simulated conformations only, the contributions from all of the simulated conformations, with Gaussian weights in the distances from a given experimental conformation, are added to give the contribution to the target function from this conformation. In contrast to earlier methods for force-field calibration, the approach does not suffer from the arbitrariness of dividing the decoy set into native-like and non-native structures; however, if such a division is made instead of using Gaussian weights, application of the maximum-likelihood method results in the well-known energy-gap maximization. The computational procedure consists of cycles of decoy generation and maximum-likelihood-function optimization, which are iterated until convergence is reached. The method was tested with Gaussian distributions and then applied to the physics-based coarse-grained UNRES force field for proteins. The NMR structures of the tryptophan cage, a small α-helical protein, determined at three temperatures (T = 280, 305, and 313 K) by Hałabis et al. ( J. Phys. Chem. B 2012 , 116 , 6898 - 6907 ), were used. Multiplexed replica-exchange molecular dynamics was used to generate the decoys. The iterative procedure exhibited steady convergence. Three variants of optimization were tried: optimization of the energy-term weights alone and use of the experimental ensemble of the folded protein only at T = 280 K (run 1); optimization of the energy-term weights and use of experimental ensembles at all three temperatures (run 2

Solar maximum: Solar array degradation

NASA Technical Reports Server (NTRS)

Miller, T.

1985-01-01

The 5-year in-orbit power degradation of the silicon solar array aboard the Solar Maximum Satellite was evaluated. This was the first spacecraft to use Teflon R FEP as a coverglass adhesive, thus avoiding the necessity of an ultraviolet filter. The peak power tracking mode of the power regulator unit was employed to ensure consistent maximum power comparisons. Telemetry was normalized to account for the effects of illumination intensity, charged particle irradiation dosage, and solar array temperature. Reference conditions of 1.0 solar constant at air mass zero and 301 K (28 C) were used as a basis for normalization. Beginning-of-life array power was 2230 watts. Currently, the array output is 1830 watts. This corresponds to a 16 percent loss in array performance over 5 years. Comparison of Solar Maximum Telemetry and predicted power levels indicate that array output is 2 percent less than predictions based on an annual 1.0 MeV equivalent election fluence of 2.34 x ten to the 13th power square centimeters space environment.

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

NASA Astrophysics Data System (ADS)

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

2017-04-01

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

New Results from the Solar Maximum Mission/Bent Crystal Spectrometer

NASA Astrophysics Data System (ADS)

Rapley, C. G.; Sylwester, J.; Phillips, K. J. H.

2017-04-01

The Bent Crystal Spectrometer (BCS) onboard the NASA Solar Maximum Mission was part of the X-ray Polychromator, which observed numerous flares and bright active regions from February to November 1980, when operation was suspended as a result of the failure of the spacecraft fine-pointing system. Observations resumed following the Space Shuttle SMM Repair Mission in April 1984 and continued until November 1989. BCS spectra have been widely used in the past to obtain temperatures, emission measures, and turbulent and bulk flows during flares, as well as element abundances. Instrumental details including calibration factors not previously published are given here, and the in-orbit performance of the BCS is evaluated. Some significant changes during the mission are described, and recommendations for future instrumentation are made. Using improved estimates for the instrument parameters and operational limits, it is now possible to obtain de-convolved calibrated spectra that show finer detail than before, providing the means for improved interpretation of the physics of the emitting plasmas. The results indicate how historical archived data can be re-used to obtain enhanced and new, scientifically valuable results.

Highly efficient maximum power point tracking using DC-DC coupled inductor single-ended primary inductance converter for photovoltaic power systems

NASA Astrophysics Data System (ADS)

Quamruzzaman, M.; Mohammad, Nur; Matin, M. A.; Alam, M. R.

2016-10-01

Solar photovoltaics (PVs) have nonlinear voltage-current characteristics, with a distinct maximum power point (MPP) depending on factors such as solar irradiance and operating temperature. To extract maximum power from the PV array at any environmental condition, DC-DC converters are usually used as MPP trackers. This paper presents the performance analysis of a coupled inductor single-ended primary inductance converter for maximum power point tracking (MPPT) in a PV system. A detailed model of the system has been designed and developed in MATLAB/Simulink. The performance evaluation has been conducted on the basis of stability, current ripple reduction and efficiency at different operating conditions. Simulation results show considerable ripple reduction in the input and output currents of the converter. Both the MPPT and converter efficiencies are significantly improved. The obtained simulation results validate the effectiveness and suitability of the converter model in MPPT and show reasonable agreement with the theoretical analysis.

Performance analysis of solar-assisted chemical heat-pump dryer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fadhel, M.I.; Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450, Melaka; Sopian, K.

2010-11-15

A solar-assisted chemical heat-pump dryer has been designed, fabricated and tested. The performance of the system has been studied under the meteorological conditions of Malaysia. The system consists of four main components: solar collector (evacuated tubes type), storage tank, solid-gas chemical heat pump unit and dryer chamber. A solid-gas chemical heat pump unit consists of reactor, condenser and evaporator. The reaction used in this study (CaCl2-NH{sub 3}). A simulation has been developed, and the predicted results are compared with those obtained from experiments. The maximum efficiency for evacuated tubes solar collector of 80% has been predicted against the maximum experimentmore » of 74%. The maximum values of solar fraction from the simulation and experiment are 0.795 and 0.713, respectively, whereas the coefficient of performance of chemical heat pump (COP{sup h}) maximum values 2.2 and 2 are obtained from simulation and experiments, respectively. The results show that any reduction of energy at condenser as a result of the decrease in solar radiation will decrease the coefficient of performance of chemical heat pump as well as decrease the efficiency of drying. (author)« less

Maximum and minimum return losses from a passive two-port network terminated with a mismatched load

NASA Technical Reports Server (NTRS)

Otoshi, T. Y.

1993-01-01

This article presents an analytical method for determining the exact distance a load is required to be offset from a passive two-port network to obtain maximum or minimum return losses from the terminated two-port network. Equations are derived in terms of two-port network S-parameters and load reflection coefficient. The equations are useful for predicting worst-case performances of some types of networks that are terminated with offset short-circuit loads.

In Vivo potassium-39 NMR spectra by the burg maximum-entropy method

NASA Astrophysics Data System (ADS)

Uchiyama, Takanori; Minamitani, Haruyuki

The Burg maximum-entropy method was applied to estimate 39K NMR spectra of mung bean root tips. The maximum-entropy spectra have as good a linearity between peak areas and potassium concentrations as those obtained by fast Fourier transform and give a better estimation of intracellular potassium concentrations. Therefore potassium uptake and loss processes of mung bean root tips are shown to be more clearly traced by the maximum-entropy method.

Relationship Between Maximum Aerobic Speed Performance and Distance Covered in Rugby Union Games.

PubMed

Swaby, Rick; Jones, Paul A; Comfort, Paul

2016-10-01

Swaby, R, Jones, PA, and Comfort, P. Relationship between maximum aerobic speed performance and distance covered in rugby union games. J Strength Cond Res 30(10): 2788-2793, 2016-Researchers have shown a clear relationship between aerobic fitness and the distance covered in professional soccer, although no research has identified such a relationship in rugby union. Therefore, the aim of the study was to identify whether there was a relationship between maximal aerobic speed (MAS) and the distance covered in rugby union games. Fourteen professional rugby union players (age = 26 ± 6 years, height = 1.90 ± 0.12 m, mass = 107.1 ± 24.1 kg) participated in this investigation. Each player performed a MAS test on 3 separate occasions during the preseason, to determine reliability and provide baseline data, and participated in 6 competitive games during the early stages of the season. Game data were collected using global positioning system technology. No significant difference (p > 0.05) in total distance covered was observed between games. Relationships between players' MAS and the average distance covered from 6 competitive games were explored using Pearson's correlation coefficients, with MAS performance showing a strong relationship with distance covered during match play (r = 0.746, p < 0.001). Significantly greater (p = 0.001, Cohen's d = 2.29) distances were covered by backs (6,544 ± 573 m) compared with the forwards (4,872 ± 857 m) during a game. Similarly, backs recorded a significantly (p = 0.001, Cohen's d = 2.20) higher MAS (4.9 ± 0.13 m·s) compared with the forwards (4.2 ± 0.43 m·s). Results of the study illustrate the importance of developing high levels of aerobic fitness to increase the distance that the athlete covers in the game.

Information Entropy Production of Maximum Entropy Markov Chains from Spike Trains

NASA Astrophysics Data System (ADS)

Cofré, Rodrigo; Maldonado, Cesar

2018-01-01

We consider the maximum entropy Markov chain inference approach to characterize the collective statistics of neuronal spike trains, focusing on the statistical properties of the inferred model. We review large deviations techniques useful in this context to describe properties of accuracy and convergence in terms of sampling size. We use these results to study the statistical fluctuation of correlations, distinguishability and irreversibility of maximum entropy Markov chains. We illustrate these applications using simple examples where the large deviation rate function is explicitly obtained for maximum entropy models of relevance in this field.

Maximum reflectance and transmittance of films coated with gapped graphene in the context of the Dirac model

NASA Astrophysics Data System (ADS)

Klimchitskaya, G. L.; Mostepanenko, V. M.

2018-06-01

The analytic expressions for the maximum and minimum reflectances of optical films coated with gapped graphene are derived in the application region of the Dirac model taking into account multiple reflections. The respective film thicknesses are also found. In so doing the film material is described by the frequency-dependent index of refraction and graphene by the polarization tensor defined along the real frequency axis. The developed formalism is illustrated by an example of the graphene-coated film made of amorphous silica. Numerical computations of the maximum and minimum reflectances and respective film thicknesses are performed at room temperature in two frequency regions belonging to the near-infrared and far-infrared domains. It is shown that in the far-infrared domain the graphene coating has a profound effect on the values of maximum reflectance and respective film thickness leading to a relative increase in their values by up to 65% and 50%, respectively. The maximum transmittance of a graphene-coated film of appropriately chosen thickness is shown to exceed 90%. Possible applications of the obtained results are discussed.

Methods for utilizing maximum power from a solar array

NASA Technical Reports Server (NTRS)

Decker, D. K.

1972-01-01

A preliminary study of maximum power utilization methods was performed for an outer planet spacecraft using an ion thruster propulsion system and a solar array as the primary energy source. The problems which arise from operating the array at or near the maximum power point of its 1-V characteristic are discussed. Two closed loop system configurations which use extremum regulators to track the array's maximum power point are presented. Three open loop systems are presented that either: (1) measure the maximum power of each array section and compute the total array power, (2) utilize a reference array to predict the characteristics of the solar array, or (3) utilize impedance measurements to predict the maximum power utilization. The advantages and disadvantages of each system are discussed and recommendations for further development are made.

Maximum static inspiratory and expiratory pressures with different lung volumes

PubMed Central

Lausted, Christopher G; Johnson, Arthur T; Scott, William H; Johnson, Monique M; Coyne, Karen M; Coursey, Derya C

2006-01-01

Background Maximum pressures developed by the respiratory muscles can indicate the health of the respiratory system, help to determine maximum respiratory flow rates, and contribute to respiratory power development. Past measurements of maximum pressures have been found to be inadequate for inclusion in some exercise models involving respiration. Methods Maximum inspiratory and expiratory airway pressures were measured over a range of lung volumes in 29 female and 19 male adults. A commercial bell spirometry system was programmed to occlude airflow at nine target lung volumes ranging from 10% to 90% of vital capacity. Results In women, maximum expiratory pressure increased with volume from 39 to 61 cmH2O and maximum inspiratory pressure decreased with volume from 66 to 28 cmH2O. In men, maximum expiratory pressure increased with volume from 63 to 97 cmH2O and maximum inspiratory pressure decreased with volume from 97 to 39 cmH2O. Equations describing pressures for both sexes are: Pe/Pmax = 0.1426 Ln( %VC) + 0.3402 R2 = 0.95 Pi/Pmax = 0.234 Ln(100 - %VC) - 0.0828 R2 = 0.96 Conclusion These results were found to be consistent with values and trends obtained by other authors. Regression equations may be suitable for respiratory mechanics models. PMID:16677384

Modeling and optimization of maximum available work for irreversible gas power cycles with temperature dependent specific heat

NASA Astrophysics Data System (ADS)

Açıkkalp, Emin; Yamık, Hasan

2015-03-01

In classical thermodynamics, the maximum power obtained from a system is defined as exergy (availability). However, the term exergy is used for reversible cycles only; in reality, reversible cycles do not exist, and all systems are irreversible. Reversible cycles do not have such restrictions as time and dimension, and are assumed to work in an equilibrium state. The objective of this study is to obtain maximum available work for SI, CI and Brayton cycles while considering the aforementioned restrictions and assumptions. We assume that the specific heat of the working fluid varies with temperature, we define optimum compression ratios and pressure ratio in order to obtain maximum available work, and we discuss the results obtained. The design parameter most appropriate for the results obtained is presented.

Maximum likelihood estimation for predicting the probability of obtaining variable shortleaf pine regeneration densities

Treesearch

Thomas B. Lynch; Jean Nkouka; Michael M. Huebschmann; James M. Guldin

2003-01-01

A logistic equation is the basis for a model that predicts the probability of obtaining regeneration at specified densities. The density of regeneration (trees/ha) for which an estimate of probability is desired can be specified by means of independent variables in the model. When estimating parameters, the dependent variable is set to 1 if the regeneration density (...

Batch Effect Confounding Leads to Strong Bias in Performance Estimates Obtained by Cross-Validation

PubMed Central

Delorenzi, Mauro

2014-01-01

Background With the large amount of biological data that is currently publicly available, many investigators combine multiple data sets to increase the sample size and potentially also the power of their analyses. However, technical differences (“batch effects”) as well as differences in sample composition between the data sets may significantly affect the ability to draw generalizable conclusions from such studies. Focus The current study focuses on the construction of classifiers, and the use of cross-validation to estimate their performance. In particular, we investigate the impact of batch effects and differences in sample composition between batches on the accuracy of the classification performance estimate obtained via cross-validation. The focus on estimation bias is a main difference compared to previous studies, which have mostly focused on the predictive performance and how it relates to the presence of batch effects. Data We work on simulated data sets. To have realistic intensity distributions, we use real gene expression data as the basis for our simulation. Random samples from this expression matrix are selected and assigned to group 1 (e.g., ‘control’) or group 2 (e.g., ‘treated’). We introduce batch effects and select some features to be differentially expressed between the two groups. We consider several scenarios for our study, most importantly different levels of confounding between groups and batch effects. Methods We focus on well-known classifiers: logistic regression, Support Vector Machines (SVM), k-nearest neighbors (kNN) and Random Forests (RF). Feature selection is performed with the Wilcoxon test or the lasso. Parameter tuning and feature selection, as well as the estimation of the prediction performance of each classifier, is performed within a nested cross-validation scheme. The estimated classification performance is then compared to what is obtained when applying the classifier to independent data. PMID:24967636

Maximum spectral demands in the near-fault region

USGS Publications Warehouse

Huang, Yin-Nan; Whittaker, Andrew S.; Luco, Nicolas

2008-01-01

The Next Generation Attenuation (NGA) relationships for shallow crustal earthquakes in the western United States predict a rotated geometric mean of horizontal spectral demand, termed GMRotI50, and not maximum spectral demand. Differences between strike-normal, strike-parallel, geometric-mean, and maximum spectral demands in the near-fault region are investigated using 147 pairs of records selected from the NGA strong motion database. The selected records are for earthquakes with moment magnitude greater than 6.5 and for closest site-to-fault distance less than 15 km. Ratios of maximum spectral demand to NGA-predicted GMRotI50 for each pair of ground motions are presented. The ratio shows a clear dependence on period and the Somerville directivity parameters. Maximum demands can substantially exceed NGA-predicted GMRotI50 demands in the near-fault region, which has significant implications for seismic design, seismic performance assessment, and the next-generation seismic design maps. Strike-normal spectral demands are a significantly unconservative surrogate for maximum spectral demands for closest distance greater than 3 to 5 km. Scale factors that transform NGA-predicted GMRotI50 to a maximum spectral demand in the near-fault region are proposed.

Bayesian Monte Carlo and Maximum Likelihood Approach for ...

EPA Pesticide Factsheets

Model uncertainty estimation and risk assessment is essential to environmental management and informed decision making on pollution mitigation strategies. In this study, we apply a probabilistic methodology, which combines Bayesian Monte Carlo simulation and Maximum Likelihood estimation (BMCML) to calibrate a lake oxygen recovery model. We first derive an analytical solution of the differential equation governing lake-averaged oxygen dynamics as a function of time-variable wind speed. Statistical inferences on model parameters and predictive uncertainty are then drawn by Bayesian conditioning of the analytical solution on observed daily wind speed and oxygen concentration data obtained from an earlier study during two recovery periods on a eutrophic lake in upper state New York. The model is calibrated using oxygen recovery data for one year and statistical inferences were validated using recovery data for another year. Compared with essentially two-step, regression and optimization approach, the BMCML results are more comprehensive and performed relatively better in predicting the observed temporal dissolved oxygen levels (DO) in the lake. BMCML also produced comparable calibration and validation results with those obtained using popular Markov Chain Monte Carlo technique (MCMC) and is computationally simpler and easier to implement than the MCMC. Next, using the calibrated model, we derive an optimal relationship between liquid film-transfer coefficien

Maximum-likelihood block detection of noncoherent continuous phase modulation

NASA Technical Reports Server (NTRS)

Simon, Marvin K.; Divsalar, Dariush

1993-01-01

This paper examines maximum-likelihood block detection of uncoded full response CPM over an additive white Gaussian noise (AWGN) channel. Both the maximum-likelihood metrics and the bit error probability performances of the associated detection algorithms are considered. The special and popular case of minimum-shift-keying (MSK) corresponding to h = 0.5 and constant amplitude frequency pulse is treated separately. The many new receiver structures that result from this investigation can be compared to the traditional ones that have been used in the past both from the standpoint of simplicity of implementation and optimality of performance.

Maximum Tsallis entropy with generalized Gini and Gini mean difference indices constraints

NASA Astrophysics Data System (ADS)

Khosravi Tanak, A.; Mohtashami Borzadaran, G. R.; Ahmadi, J.

2017-04-01

Using the maximum entropy principle with Tsallis entropy, some distribution families for modeling income distribution are obtained. By considering income inequality measures, maximum Tsallis entropy distributions under the constraint on generalized Gini and Gini mean difference indices are derived. It is shown that the Tsallis entropy maximizers with the considered constraints belong to generalized Pareto family.

New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0.

PubMed

Guindon, Stéphane; Dufayard, Jean-François; Lefort, Vincent; Anisimova, Maria; Hordijk, Wim; Gascuel, Olivier

2010-05-01

PhyML is a phylogeny software based on the maximum-likelihood principle. Early PhyML versions used a fast algorithm performing nearest neighbor interchanges to improve a reasonable starting tree topology. Since the original publication (Guindon S., Gascuel O. 2003. A simple, fast and accurate algorithm to estimate large phylogenies by maximum likelihood. Syst. Biol. 52:696-704), PhyML has been widely used (>2500 citations in ISI Web of Science) because of its simplicity and a fair compromise between accuracy and speed. In the meantime, research around PhyML has continued, and this article describes the new algorithms and methods implemented in the program. First, we introduce a new algorithm to search the tree space with user-defined intensity using subtree pruning and regrafting topological moves. The parsimony criterion is used here to filter out the least promising topology modifications with respect to the likelihood function. The analysis of a large collection of real nucleotide and amino acid data sets of various sizes demonstrates the good performance of this method. Second, we describe a new test to assess the support of the data for internal branches of a phylogeny. This approach extends the recently proposed approximate likelihood-ratio test and relies on a nonparametric, Shimodaira-Hasegawa-like procedure. A detailed analysis of real alignments sheds light on the links between this new approach and the more classical nonparametric bootstrap method. Overall, our tests show that the last version (3.0) of PhyML is fast, accurate, stable, and ready to use. A Web server and binary files are available from http://www.atgc-montpellier.fr/phyml/.

The use of a numerical method to justify the criteria for the maximum settlement of the tank foundation

NASA Astrophysics Data System (ADS)

Tarasenko, Alexander; Chepur, Petr; Gruchenkova, Alesya

2017-11-01

The article examines the problem of assessing the permissible values of uneven settlement for a vertical steel tank base and foundation. A numerical experiment was performed using a finite element model of the tank. The model took into account the geometric shape of the structure and its additional stiffening elements that affect the stress-strain state of the tank. An equation was obtained that allowed determining the maximum possible deformation of the bottom outer contour during uneven settlement. Depending on the length of the uneven settlement zone, the values of the permissible settlement of the tank base were determined. The article proposes new values of the maximum permissible tank settlement with additional stiffening elements.

Double-tailored nonimaging reflector optics for maximum-performance solar concentration.

PubMed

Goldstein, Alex; Gordon, Jeffrey M

2010-09-01

A nonimaging strategy that tailors two mirror contours for concentration near the étendue limit is explored, prompted by solar applications where a sizable gap between the optic and absorber is required. Subtle limitations of this simultaneous multiple surface method approach are derived, rooted in the manner in which phase space boundaries can be tailored according to the edge-ray principle. The fundamental categories of double-tailored reflective optics are identified, only a minority of which can pragmatically offer maximum concentration at high collection efficiency. Illustrative examples confirm that acceptance half-angles as large as 30 mrad can be realized at a flux concentration of approximately 1000.

Maximum power point tracking for photovoltaic applications by using two-level DC/DC boost converter

NASA Astrophysics Data System (ADS)

Moamaei, Parvin

Recently, photovoltaic (PV) generation is becoming increasingly popular in industrial applications. As a renewable and alternative source of energy they feature superior characteristics such as being clean and silent along with less maintenance problems compared to other sources of the energy. In PV generation, employing a Maximum Power Point Tracking (MPPT) method is essential to obtain the maximum available solar energy. Among several proposed MPPT techniques, the Perturbation and Observation (P&O;) and Model Predictive Control (MPC) methods are adopted in this work. The components of the MPPT control system which are P&O; and MPC algorithms, PV module and high gain DC-DC boost converter are simulated in MATLAB Simulink. They are evaluated theoretically under rapidly and slowly changing of solar irradiation and temperature and their performance is shown by the simulation results, finally a comprehensive comparison is presented.

Watershed Regressions for Pesticides (WARP) for Predicting Annual Maximum and Annual Maximum Moving-Average Concentrations of Atrazine in Streams

USGS Publications Warehouse

Stone, Wesley W.; Gilliom, Robert J.; Crawford, Charles G.

2008-01-01

Regression models were developed for predicting annual maximum and selected annual maximum moving-average concentrations of atrazine in streams using the Watershed Regressions for Pesticides (WARP) methodology developed by the National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey (USGS). The current effort builds on the original WARP models, which were based on the annual mean and selected percentiles of the annual frequency distribution of atrazine concentrations. Estimates of annual maximum and annual maximum moving-average concentrations for selected durations are needed to characterize the levels of atrazine and other pesticides for comparison to specific water-quality benchmarks for evaluation of potential concerns regarding human health or aquatic life. Separate regression models were derived for the annual maximum and annual maximum 21-day, 60-day, and 90-day moving-average concentrations. Development of the regression models used the same explanatory variables, transformations, model development data, model validation data, and regression methods as those used in the original development of WARP. The models accounted for 72 to 75 percent of the variability in the concentration statistics among the 112 sampling sites used for model development. Predicted concentration statistics from the four models were within a factor of 10 of the observed concentration statistics for most of the model development and validation sites. Overall, performance of the models for the development and validation sites supports the application of the WARP models for predicting annual maximum and selected annual maximum moving-average atrazine concentration in streams and provides a framework to interpret the predictions in terms of uncertainty. For streams with inadequate direct measurements of atrazine concentrations, the WARP model predictions for the annual maximum and the annual maximum moving-average atrazine concentrations can be used to characterize

Application of thin-layer Navier-Stokes equations near maximum lift

NASA Technical Reports Server (NTRS)

Anderson, W. K.; Thomas, J. L.; Rumsey, C. L.

1984-01-01

The flowfield about a NACA 0012 airfoil at a Mach number of 0.3 and Reynolds number of 1 million is computed through an angle of attack range, up to 18 deg, corresponding to conditions up to and beyond the maximum lift coefficient. Results obtained using the compressible thin-layer Navier-Stokes equations are presented as well as results from the compressible Euler equations with and without a viscous coupling procedure. The applicability of each code is assessed and many thin-layer Navier-Stokes benchmark solutions are obtained which can be used for comparison with other codes intended for use at high angles of attack. Reasonable agreement of the Navier-Stokes code with experiment and the viscous-inviscid interaction code is obtained at moderate angles of attack. An unsteady solution is obtained with the thin-layer Navier-Stokes code at the highest angle of attack considered. The maximum lift coefficient is overpredicted, however, in comparison to experimental data, which is attributed to the presence of a laminar separation bubble near the leading edge not modeled in the computations. Two comparisons with experimental data are also presented at a higher Mach number.

Minimum and Maximum Times Required to Obtain Representative Suspended Sediment Samples

NASA Astrophysics Data System (ADS)

Gitto, A.; Venditti, J. G.; Kostaschuk, R.; Church, M. A.

2014-12-01

Bottle sampling is a convenient method of obtaining suspended sediment measurements for the development of sediment budgets. While these methods are generally considered to be reliable, recent analysis of depth-integrated sampling has identified considerable uncertainty in measurements of grain-size concentration between grain-size classes of multiple samples. Point-integrated bottle sampling is assumed to represent the mean concentration of suspended sediment but the uncertainty surrounding this method is not well understood. Here we examine at-a-point variability in velocity, suspended sediment concentration, grain-size distribution, and grain-size moments to determine if traditional point-integrated methods provide a representative sample of suspended sediment. We present continuous hour-long observations of suspended sediment from the sand-bedded portion of the Fraser River at Mission, British Columbia, Canada, using a LISST laser-diffraction instrument. Spectral analysis suggests that there are no statistically significant peak in energy density, suggesting the absence of periodic fluctuations in flow and suspended sediment. However, a slope break in the spectra at 0.003 Hz corresponds to a period of 5.5 minutes. This coincides with the threshold between large-scale turbulent eddies that scale with channel width/mean velocity and hydraulic phenomena related to channel dynamics. This suggests that suspended sediment samples taken over a period longer than 5.5 minutes incorporate variability that is larger scale than turbulent phenomena in this channel. Examination of 5.5-minute periods of our time series indicate that ~20% of the time a stable mean value of volumetric concentration is reached within 30 seconds, a typical bottle sample duration. In ~12% of measurements a stable mean was not reached over the 5.5 minute sample duration. The remaining measurements achieve a stable mean in an even distribution over the intervening interval.

Maximum likelihood decoding analysis of accumulate-repeat-accumulate codes

NASA Technical Reports Server (NTRS)

Abbasfar, A.; Divsalar, D.; Yao, K.

2004-01-01

In this paper, the performance of the repeat-accumulate codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. Some simple codes are shown that perform very close to Shannon limit with maximum likelihood decoding.

Maximum power point tracker for photovoltaic power plants

NASA Astrophysics Data System (ADS)

Arcidiacono, V.; Corsi, S.; Lambri, L.

The paper describes two different closed-loop control criteria for the maximum power point tracking of the voltage-current characteristic of a photovoltaic generator. The two criteria are discussed and compared, inter alia, with regard to the setting-up problems that they pose. Although a detailed analysis is not embarked upon, the paper also provides some quantitative information on the energy advantages obtained by using electronic maximum power point tracking systems, as compared with the situation in which the point of operation of the photovoltaic generator is not controlled at all. Lastly, the paper presents two high-efficiency MPPT converters for experimental photovoltaic plants of the stand-alone and the grid-interconnected type.

Maximum spectral demands in the near-fault region

USGS Publications Warehouse

Huang, Y.-N.; Whittaker, A.S.; Luco, N.

2008-01-01

The Next Generation Attenuation (NGA) relationships for shallow crustal earthquakes in the western United States predict a rotated geometric mean of horizontal spectral demand, termed GMRotI50, and not maximum spectral demand. Differences between strike-normal, strike-parallel, geometric-mean, and maximum spectral demands in the near-fault region are investigated using 147 pairs of records selected from the NGA strong motion database. The selected records are for earthquakes with moment magnitude greater than 6.5 and for closest site-to-fault distance less than 15 km. Ratios of maximum spectral demand to NGA-predicted GMRotI50 for each pair of ground motions are presented. The ratio shows a clear dependence on period and the Somerville directivity parameters. Maximum demands can substantially exceed NGA-predicted GMRotI50 demands in the near-fault region, which has significant implications for seismic design, seismic performance assessment, and the next-generation seismic design maps. Strike-normal spectral demands are a significantly unconservative surrogate for maximum spectral demands for closest distance greater than 3 to 5 km. Scale factors that transform NGA-predicted GMRotI50 to a maximum spectral demand in the near-fault region are proposed. ?? 2008, Earthquake Engineering Research Institute.

Performance advantages of maximum likelihood methods in PRBS-modulated time-of-flight electron energy loss spectroscopy

NASA Astrophysics Data System (ADS)

Yang, Zhongyu

This thesis describes the design, experimental performance, and theoretical simulation of a novel time-of-flight analyzer that was integrated into a high resolution electron energy loss spectrometer (TOF-HREELS). First we examined the use of an interleaved comb chopper for chopping a continuous electron beam. Both static and dynamic behaviors were simulated theoretically and measured experimentally, with very good agreement. The finite penetration of the field beyond the plane of the chopper leads to non-ideal chopper response, which is characterized in terms of an "energy corruption" effect and a lead or lag in the time at which the beam responds to the chopper potential. Second we considered the recovery of spectra from pseudo-random binary sequence (PRBS) modulated TOF-HREELS data. The effects of the Poisson noise distribution and the non-ideal behavior of the "interleaved comb" chopper were simulated. We showed, for the first time, that maximum likelihood methods can be combined with PRBS modulation to achieve resolution enhancement, while properly accounting for the Poisson noise distribution and artifacts introduced by the chopper. Our results indicate that meV resolution, similar to that of modern high resolution electron energy loss spectrometers, can be achieved with a dramatic performance advantage over conventional, serial detection analyzers. To demonstrate the capabilities of the TOF-HREELS instrument, we made measurements on a highly oriented thin film polytetrafluoroethylene (PTFE) sample. We demonstrated that the TOF-HREELS can achieve a throughput advantage of a factor of 85 compared to the conventional HREELS instrument. Comparisons were made between the experimental results and theoretical simulations. We discuss various factors which affect inversion of PRBS modulated Time of Flight (TOF) data with the Lucy algorithm. Using simulations, we conclude that the convolution assumption was good under the conditions of our experiment. The chopper rise

Maximum-biomass prediction of homofermentative Lactobacillus.

PubMed

Cui, Shumao; Zhao, Jianxin; Liu, Xiaoming; Chen, Yong Q; Zhang, Hao; Chen, Wei

2016-07-01

Fed-batch and pH-controlled cultures have been widely used for industrial production of probiotics. The aim of this study was to systematically investigate the relationship between the maximum biomass of different homofermentative Lactobacillus and lactate accumulation, and to develop a prediction equation for the maximum biomass concentration in such cultures. The accumulation of the end products and the depletion of nutrients by various strains were evaluated. In addition, the minimum inhibitory concentrations (MICs) of acid anions for various strains at pH 7.0 were examined. The lactate concentration at the point of complete inhibition was not significantly different from the MIC of lactate for all of the strains, although the inhibition mechanism of lactate and acetate on Lactobacillus rhamnosus was different from the other strains which were inhibited by the osmotic pressure caused by acid anions at pH 7.0. When the lactate concentration accumulated to the MIC, the strains stopped growing. The maximum biomass was closely related to the biomass yield per unit of lactate produced (YX/P) and the MIC (C) of lactate for different homofermentative Lactobacillus. Based on the experimental data obtained using different homofermentative Lactobacillus, a prediction equation was established as follows: Xmax - X0 = (0.59 ± 0.02)·YX/P·C. Copyright © 2016. Published by Elsevier B.V.

High-performance multi-functional reverse osmosis membranes obtained by carbon nanotube·polyamide nanocomposite

PubMed Central

Inukai, Shigeki; Cruz-Silva, Rodolfo; Ortiz-Medina, Josue; Morelos-Gomez, Aaron; Takeuchi, Kenji; Hayashi, Takuya; Tanioka, Akihiko; Araki, Takumi; Tejima, Syogo; Noguchi, Toru; Terrones, Mauricio; Endo, Morinobu

2015-01-01

Clean water obtained by desalinating sea water or by purifying wastewater, constitutes a major technological objective in the so-called water century. In this work, a high-performance reverse osmosis (RO) composite thin membrane using multi-walled carbon nanotubes (MWCNT) and aromatic polyamide (PA), was successfully prepared by interfacial polymerization. The effect of MWCNT on the chlorine resistance, antifouling and desalination performances of the nanocomposite membranes were studied. We found that a suitable amount of MWCNT in PA, 15.5 wt.%, not only improves the membrane performance in terms of flow and antifouling, but also inhibits the chlorine degradation on these membranes. Therefore, the present results clearly establish a solid foundation towards more efficient large-scale water desalination and other water treatment processes. PMID:26333385

Maximum powers of low-loss series-shunt FET RF switches

NASA Astrophysics Data System (ADS)

Yang, Z.; Hu, X.; Yang, J.; Simin, G.; Shur, M.; Gaska, R.

2009-02-01

Low-loss high-power single pole single throw (SPST) monolithic RF switch based on AlGaN/GaN heterojunction field effect transistors (HFETs) demonstrate the insertion loss and isolation of 0.15 dB and 45.9 dB at 0.5 GHz and 0.23 dB and 34.3 dB at 2 GHz. Maximum switching powers are estimated +47 dBm or higher. Factors determining the maximum switching powers are analyzed. Design principles to obtain equally high switching powers in the ON and OFF-states are developed.

A general methodology for maximum likelihood inference from band-recovery data

USGS Publications Warehouse

Conroy, M.J.; Williams, B.K.

1984-01-01

A numerical procedure is described for obtaining maximum likelihood estimates and associated maximum likelihood inference from band- recovery data. The method is used to illustrate previously developed one-age-class band-recovery models, and is extended to new models, including the analysis with a covariate for survival rates and variable-time-period recovery models. Extensions to R-age-class band- recovery, mark-recapture models, and twice-yearly marking are discussed. A FORTRAN program provides computations for these models.

Limitations to maximum running speed on flat curves.

PubMed

Chang, Young-Hui; Kram, Rodger

2007-03-01

Why is maximal running speed reduced on curved paths? The leading explanation proposes that an increase in lateral ground reaction force necessitates a decrease in peak vertical ground reaction force, assuming that maximum leg extension force is the limiting factor. Yet, no studies have directly measured these forces or tested this critical assumption. We measured maximum sprint velocities and ground reaction forces for five male humans sprinting along a straight track and compared them to sprints along circular tracks of 1, 2, 3, 4 and 6 m radii. Circular track sprint trials were performed either with or without a tether that applied centripetal force to the center of mass. Sprinters generated significantly smaller peak resultant ground reaction forces during normal curve sprinting compared to straight sprinting. This provides direct evidence against the idea that maximum leg extension force is always achieved and is the limiting factor. Use of the tether increased sprint speed, but not to expected values. During curve sprinting, the inside leg consistently generated smaller peak forces compared to the outside leg. Several competing biomechanical constraints placed on the stance leg during curve sprinting likely make the inside leg particularly ineffective at generating the ground reaction forces necessary to attain maximum velocities comparable to straight path sprinting. The ability of quadrupeds to redistribute function across multiple stance legs and decouple these multiple constraints may provide a distinct advantage for turning performance.

Validity of maximal isometric knee extension strength measurements obtained via belt-stabilized hand-held dynamometry in healthy adults.

PubMed

Ushiyama, Naoko; Kurobe, Yasushi; Momose, Kimito

2017-11-01

[Purpose] To determine the validity of knee extension muscle strength measurements using belt-stabilized hand-held dynamometry with and without body stabilization compared with the gold standard isokinetic dynamometry in healthy adults. [Subjects and Methods] Twenty-nine healthy adults (mean age, 21.3 years) were included. Study parameters involved right side measurements of maximal isometric knee extension strength obtained using belt-stabilized hand-held dynamometry with and without body stabilization and the gold standard. Measurements were performed in all subjects. [Results] A moderate correlation and fixed bias were found between measurements obtained using belt-stabilized hand-held dynamometry with body stabilization and the gold standard. No significant correlation and proportional bias were found between measurements obtained using belt-stabilized hand-held dynamometry without body stabilization and the gold standard. The strength identified using belt-stabilized hand-held dynamometry with body stabilization may not be commensurate with the maximum strength individuals can generate; however, it reflects such strength. In contrast, the strength identified using belt-stabilized hand-held dynamometry without body stabilization does not reflect the maximum strength. Therefore, a chair should be used to stabilize the body when performing measurements of maximal isometric knee extension strength using belt-stabilized hand-held dynamometry in healthy adults. [Conclusion] Belt-stabilized hand-held dynamometry with body stabilization is more convenient than the gold standard in clinical settings.

Finite mixture model: A maximum likelihood estimation approach on time series data

NASA Astrophysics Data System (ADS)

Yen, Phoong Seuk; Ismail, Mohd Tahir; Hamzah, Firdaus Mohamad

2014-09-01

Recently, statistician emphasized on the fitting of finite mixture model by using maximum likelihood estimation as it provides asymptotic properties. In addition, it shows consistency properties as the sample sizes increases to infinity. This illustrated that maximum likelihood estimation is an unbiased estimator. Moreover, the estimate parameters obtained from the application of maximum likelihood estimation have smallest variance as compared to others statistical method as the sample sizes increases. Thus, maximum likelihood estimation is adopted in this paper to fit the two-component mixture model in order to explore the relationship between rubber price and exchange rate for Malaysia, Thailand, Philippines and Indonesia. Results described that there is a negative effect among rubber price and exchange rate for all selected countries.

Performance Based Leadership Development in Organizational Settings

DTIC Science & Technology

1979-09-01

in order to obtain the maximum performance from a group of subordinates and also maintain the subordinates’ satisfaction , Lt. Jones, o£ any other... performance and worker satisfaction . You might ask why the Developmental Model of Leadership is based upon these three assumrtions. The rationale for making...This theory then discusses the conditions under which each of these behaviors mty lead to better subordinate performance and satisfaction . The path-goal

Maximum Likelihood and Restricted Likelihood Solutions in Multiple-Method Studies.

PubMed

Rukhin, Andrew L

2011-01-01

A formulation of the problem of combining data from several sources is discussed in terms of random effects models. The unknown measurement precision is assumed not to be the same for all methods. We investigate maximum likelihood solutions in this model. By representing the likelihood equations as simultaneous polynomial equations, the exact form of the Groebner basis for their stationary points is derived when there are two methods. A parametrization of these solutions which allows their comparison is suggested. A numerical method for solving likelihood equations is outlined, and an alternative to the maximum likelihood method, the restricted maximum likelihood, is studied. In the situation when methods variances are considered to be known an upper bound on the between-method variance is obtained. The relationship between likelihood equations and moment-type equations is also discussed.

Using iMCFA to Perform the CFA, Multilevel CFA, and Maximum Model for Analyzing Complex Survey Data.

PubMed

Wu, Jiun-Yu; Lee, Yuan-Hsuan; Lin, John J H

2018-01-01

To construct CFA, MCFA, and maximum MCFA with LISREL v.8 and below, we provide iMCFA (integrated Multilevel Confirmatory Analysis) to examine the potential multilevel factorial structure in the complex survey data. Modeling multilevel structure for complex survey data is complicated because building a multilevel model is not an infallible statistical strategy unless the hypothesized model is close to the real data structure. Methodologists have suggested using different modeling techniques to investigate potential multilevel structure of survey data. Using iMCFA, researchers can visually set the between- and within-level factorial structure to fit MCFA, CFA and/or MAX MCFA models for complex survey data. iMCFA can then yield between- and within-level variance-covariance matrices, calculate intraclass correlations, perform the analyses and generate the outputs for respective models. The summary of the analytical outputs from LISREL is gathered and tabulated for further model comparison and interpretation. iMCFA also provides LISREL syntax of different models for researchers' future use. An empirical and a simulated multilevel dataset with complex and simple structures in the within or between level was used to illustrate the usability and the effectiveness of the iMCFA procedure on analyzing complex survey data. The analytic results of iMCFA using Muthen's limited information estimator were compared with those of Mplus using Full Information Maximum Likelihood regarding the effectiveness of different estimation methods.

Design of simplified maximum-likelihood receivers for multiuser CPM systems.

PubMed

Bing, Li; Bai, Baoming

2014-01-01

A class of simplified maximum-likelihood receivers designed for continuous phase modulation based multiuser systems is proposed. The presented receiver is built upon a front end employing mismatched filters and a maximum-likelihood detector defined in a low-dimensional signal space. The performance of the proposed receivers is analyzed and compared to some existing receivers. Some schemes are designed to implement the proposed receivers and to reveal the roles of different system parameters. Analysis and numerical results show that the proposed receivers can approach the optimum multiuser receivers with significantly (even exponentially in some cases) reduced complexity and marginal performance degradation.

Characteristics of Plantar Loads in Maximum Forward Lunge Tasks in Badminton.

PubMed

Hu, Xiaoyue; Li, Jing Xian; Hong, Youlian; Wang, Lin

2015-01-01

Badminton players often perform powerful and long-distance lunges during such competitive matches. The objective of this study is to compare the plantar loads of three one-step maximum forward lunges in badminton. Fifteen right-handed male badminton players participated in the study. Each participant performed five successful maximum lunges at three directions. For each direction, the participant wore three different shoe brands. Plantar loading, including peak pressure, maximum force, and contact area, was measured by using an insole pressure measurement system. Two-way ANOVA with repeated measures was employed to determine the effects of the different lunge directions and different shoes, as well as the interaction of these two variables, on the measurements. The maximum force (MF) on the lateral midfoot was lower when performing left-forward lunges than when performing front-forward lunges (p = 0.006, 95% CI = -2.88 to -0.04%BW). The MF and peak pressures (PP) on the great toe region were lower for the front-forward lunge than for the right-forward lunge (MF, p = 0.047, 95% CI = -3.62 to -0.02%BW; PP, p = 0.048, 95% CI = -37.63 to -0.16 KPa) and left-forward lunge (MF, p = 0.015, 95% CI = -4.39 to -0.38%BW; PP, p = 0.008, 95% CI = -47.76 to -5.91 KPa). These findings indicate that compared with the front-forward lunge, left and right maximum forward lunges induce greater plantar loads on the great toe region of the dominant leg of badminton players. The differences in the plantar loads of the different lunge directions may be potential risks for injuries to the lower extremities of badminton players.

Microprocessor-controlled step-down maximum-power-point tracker for photovoltaic systems

NASA Astrophysics Data System (ADS)

Mazmuder, R. K.; Haidar, S.

1992-12-01

An efficient maximum power point tracker (MPPT) has been developed and can be used with a photovoltaic (PV) array and a load which requires lower voltage than the PV array voltage to be operated. The MPPT makes the PV array to operate at maximum power point (MPP) under all insolation and temperature, which ensures the maximum amount of available PV power to be delivered to the load. The performance of the MPPT has been studied under different insolation levels.

Temperature of maximum density and excess thermodynamics of aqueous mixtures of methanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

González-Salgado, D.; Zemánková, K.; Noya, E. G.

In this work, we present a study of representative excess thermodynamic properties of aqueous mixtures of methanol over the complete concentration range, based on extensive computer simulation calculations. In addition to test various existing united atom model potentials, we have developed a new force-field which accurately reproduces the excess thermodynamics of this system. Moreover, we have paid particular attention to the behavior of the temperature of maximum density (TMD) in dilute methanol mixtures. The presence of a temperature of maximum density is one of the essential anomalies exhibited by water. This anomalous behavior is modified in a non-monotonous fashion bymore » the presence of fully miscible solutes that partly disrupt the hydrogen bond network of water, such as methanol (and other short chain alcohols). In order to obtain a better insight into the phenomenology of the changes in the TMD of water induced by small amounts of methanol, we have performed a new series of experimental measurements and computer simulations using various force fields. We observe that none of the force-fields tested capture the non-monotonous concentration dependence of the TMD for highly diluted methanol solutions.« less

Variability of maximum systolic amplitude of ΔZ/Δt curve in pregnancy. Perennial observations

NASA Astrophysics Data System (ADS)

Ilyin, I.; Karpov, A.; Korotkova, M.

2010-04-01

Maximum systolic amplitude is quite an important component of the impedance cardiogram ΔZ/Δt curve. Its values make it possible to calculate many hemodynamic indices. Therefore it is necessary to keep informed about monthly, annual and perennial maximum systolic amplitude trend. We can produce the measuring data of the maximum systolic amplitude for a fifteen-year period (from 1994 to 2009). The impedance cardiograms were obtained with the help of an electric impedance analyzer "RA-5" (1 mA, 70 kHz) with disk ECG electrodes. The data analyzed were taken from the pregnant women with non-complicated pregnancy (n=5709). We have analyzed the average monthly and annual changes of the maximum systolic amplitude ΔZ/Δt curve. It allowed us to reveal the six-year periodicity of the maximum systolic amplitude changes. There were discovered statistically significant peak values difference of the amplitude (p>0.001). The data obtained should be taken into consideration when using impedance cardiography in clinical practice. The article is supplied with tables and diagrams.

In-flight calibration and performance evaluation of the fixed head star trackers for the solar maximum mission

NASA Technical Reports Server (NTRS)

Thompson, R. H.; Gambardella, P. J.

1980-01-01

The Solar Maximum Mission (SMM) spacecraft provides an excellent opportunity for evaluating attitude determination accuracies achievable with tracking instruments such as fixed head star trackers (FHSTs). As a part of its payload, SMM carries a highly accurate fine pointing Sun sensor (FPSS). The EPSS provides an independent check of the pitch and yaw parameters computed from observations of stars in the FHST field of view. A method to determine the alignment of the FHSTs relative to the FPSS using spacecraft data is applied. Two methods that were used to determine distortions in the 8 degree by 8 degree field of view of the FHSTs using spacecraft data are also presented. The attitude determination accuracy performance of the in flight calibrated FHSTs is evaluated.

Propane spectral resolution enhancement by the maximum entropy method

NASA Technical Reports Server (NTRS)

Bonavito, N. L.; Stewart, K. P.; Hurley, E. J.; Yeh, K. C.; Inguva, R.

1990-01-01

The Burg algorithm for maximum entropy power spectral density estimation is applied to a time series of data obtained from a Michelson interferometer and compared with a standard FFT estimate for resolution capability. The propane transmittance spectrum was estimated by use of the FFT with a 2 to the 18th data sample interferogram, giving a maximum unapodized resolution of 0.06/cm. This estimate was then interpolated by zero filling an additional 2 to the 18th points, and the final resolution was taken to be 0.06/cm. Comparison of the maximum entropy method (MEM) estimate with the FFT was made over a 45/cm region of the spectrum for several increasing record lengths of interferogram data beginning at 2 to the 10th. It is found that over this region the MEM estimate with 2 to the 16th data samples is in close agreement with the FFT estimate using 2 to the 18th samples.

DSN telemetry system performance with convolutionally code data

NASA Technical Reports Server (NTRS)

Mulhall, B. D. L.; Benjauthrit, B.; Greenhall, C. A.; Kuma, D. M.; Lam, J. K.; Wong, J. S.; Urech, J.; Vit, L. D.

1975-01-01

The results obtained to date and the plans for future experiments for the DSN telemetry system were presented. The performance of the DSN telemetry system in decoding convolutionally coded data by both sequential and maximum likelihood techniques is being determined by testing at various deep space stations. The evaluation of performance models is also an objective of this activity.

Comparing methods to estimate Reineke’s maximum size-density relationship species boundary line slope

Treesearch

Curtis L. VanderSchaaf; Harold E. Burkhart

2010-01-01

Maximum size-density relationships (MSDR) provide natural resource managers useful information about the relationship between tree density and average tree size. Obtaining a valid estimate of how maximum tree density changes as average tree size changes is necessary to accurately describe these relationships. This paper examines three methods to estimate the slope of...

Maximum Principle for General Controlled Systems Driven by Fractional Brownian Motions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han Yuecai; Hu Yaozhong; Song Jian, E-mail: jsong2@math.rutgers.edu

2013-04-15

We obtain a maximum principle for stochastic control problem of general controlled stochastic differential systems driven by fractional Brownian motions (of Hurst parameter H>1/2). This maximum principle specifies a system of equations that the optimal control must satisfy (necessary condition for the optimal control). This system of equations consists of a backward stochastic differential equation driven by both fractional Brownian motions and the corresponding underlying standard Brownian motions. In addition to this backward equation, the maximum principle also involves the Malliavin derivatives. Our approach is to use conditioning and Malliavin calculus. To arrive at our maximum principle we need tomore » develop some new results of stochastic analysis of the controlled systems driven by fractional Brownian motions via fractional calculus. Our approach of conditioning and Malliavin calculus is also applied to classical system driven by standard Brownian motions while the controller has only partial information. As a straightforward consequence, the classical maximum principle is also deduced in this more natural and simpler way.« less

Behavior of high-performance concrete in structural applications.

DOT National Transportation Integrated Search

2007-10-01

High Performance Concrete (HPC) with improved properties has been developed by obtaining the maximum density of the matrix. Mathematical models developed by J.E. Funk and D.R. Dinger, are used to determine the particle size distribution to achieve th...

Unification of field theory and maximum entropy methods for learning probability densities.

PubMed

Kinney, Justin B

2015-09-01

The need to estimate smooth probability distributions (a.k.a. probability densities) from finite sampled data is ubiquitous in science. Many approaches to this problem have been described, but none is yet regarded as providing a definitive solution. Maximum entropy estimation and Bayesian field theory are two such approaches. Both have origins in statistical physics, but the relationship between them has remained unclear. Here I unify these two methods by showing that every maximum entropy density estimate can be recovered in the infinite smoothness limit of an appropriate Bayesian field theory. I also show that Bayesian field theory estimation can be performed without imposing any boundary conditions on candidate densities, and that the infinite smoothness limit of these theories recovers the most common types of maximum entropy estimates. Bayesian field theory thus provides a natural test of the maximum entropy null hypothesis and, furthermore, returns an alternative (lower entropy) density estimate when the maximum entropy hypothesis is falsified. The computations necessary for this approach can be performed rapidly for one-dimensional data, and software for doing this is provided.

Unification of field theory and maximum entropy methods for learning probability densities

NASA Astrophysics Data System (ADS)

Kinney, Justin B.

2015-09-01

The need to estimate smooth probability distributions (a.k.a. probability densities) from finite sampled data is ubiquitous in science. Many approaches to this problem have been described, but none is yet regarded as providing a definitive solution. Maximum entropy estimation and Bayesian field theory are two such approaches. Both have origins in statistical physics, but the relationship between them has remained unclear. Here I unify these two methods by showing that every maximum entropy density estimate can be recovered in the infinite smoothness limit of an appropriate Bayesian field theory. I also show that Bayesian field theory estimation can be performed without imposing any boundary conditions on candidate densities, and that the infinite smoothness limit of these theories recovers the most common types of maximum entropy estimates. Bayesian field theory thus provides a natural test of the maximum entropy null hypothesis and, furthermore, returns an alternative (lower entropy) density estimate when the maximum entropy hypothesis is falsified. The computations necessary for this approach can be performed rapidly for one-dimensional data, and software for doing this is provided.

Incorporating priors on expert performance parameters for segmentation validation and label fusion: a maximum a posteriori STAPLE

PubMed Central

Commowick, Olivier; Warfield, Simon K

2010-01-01

In order to evaluate the quality of segmentations of an image and assess intra- and inter-expert variability in segmentation performance, an Expectation Maximization (EM) algorithm for Simultaneous Truth And Performance Level Estimation (STAPLE) was recently developed. This algorithm, originally presented for segmentation validation, has since been used for many applications, such as atlas construction and decision fusion. However, the manual delineation of structures of interest is a very time consuming and burdensome task. Further, as the time required and burden of manual delineation increase, the accuracy of the delineation is decreased. Therefore, it may be desirable to ask the experts to delineate only a reduced number of structures or the segmentation of all structures by all experts may simply not be achieved. Fusion from data with some structures not segmented by each expert should be carried out in a manner that accounts for the missing information. In other applications, locally inconsistent segmentations may drive the STAPLE algorithm into an undesirable local optimum, leading to misclassifications or misleading experts performance parameters. We present a new algorithm that allows fusion with partial delineation and which can avoid convergence to undesirable local optima in the presence of strongly inconsistent segmentations. The algorithm extends STAPLE by incorporating prior probabilities for the expert performance parameters. This is achieved through a Maximum A Posteriori formulation, where the prior probabilities for the performance parameters are modeled by a beta distribution. We demonstrate that this new algorithm enables dramatically improved fusion from data with partial delineation by each expert in comparison to fusion with STAPLE. PMID:20879379

Incorporating priors on expert performance parameters for segmentation validation and label fusion: a maximum a posteriori STAPLE.

PubMed

Commowick, Olivier; Warfield, Simon K

2010-01-01

In order to evaluate the quality of segmentations of an image and assess intra- and inter-expert variability in segmentation performance, an Expectation Maximization (EM) algorithm for Simultaneous Truth And Performance Level Estimation (STAPLE) was recently developed. This algorithm, originally presented for segmentation validation, has since been used for many applications, such as atlas construction and decision fusion. However, the manual delineation of structures of interest is a very time consuming and burdensome task. Further, as the time required and burden of manual delineation increase, the accuracy of the delineation is decreased. Therefore, it may be desirable to ask the experts to delineate only a reduced number of structures or the segmentation of all structures by all experts may simply not be achieved. Fusion from data with some structures not segmented by each expert should be carried out in a manner that accounts for the missing information. In other applications, locally inconsistent segmentations may drive the STAPLE algorithm into an undesirable local optimum, leading to misclassifications or misleading experts performance parameters. We present a new algorithm that allows fusion with partial delineation and which can avoid convergence to undesirable local optima in the presence of strongly inconsistent segmentations. The algorithm extends STAPLE by incorporating prior probabilities for the expert performance parameters. This is achieved through a Maximum A Posteriori formulation, where the prior probabilities for the performance parameters are modeled by a beta distribution. We demonstrate that this new algorithm enables dramatically improved fusion from data with partial delineation by each expert in comparison to fusion with STAPLE.

Wind-tunnel and Flight Investigations of the Use of Leading-Edge Area Suction for the Purpose of Increasing the Maximum Lift Coefficient of a 35 Degree Swept-Wing Airplane

NASA Technical Reports Server (NTRS)

Holzhauser, Curt A; Bray, Richard S

1956-01-01

An investigation was undertaken to determine the increase in maximum lift coefficient that could be obtained by applying area suction near the leading edge of a wing. This investigation was performed first with a 35 degree swept-wing model in the wind tunnel, and then with an operational 35 degree swept-wing airplane which was modified in accord with the wind-tunnel results. The wind-tunnel and flight tests indicated that the maximum lift coefficient was increased more than 50 percent by the use of area suction. Good agreement was obtained in the comparison of the wind-tunnel results with those measured in flight.

Maximum Rate of Growth of Enstrophy in Solutions of the Fractional Burgers Equation

NASA Astrophysics Data System (ADS)

Yun, Dongfang; Protas, Bartosz

2018-02-01

This investigation is a part of a research program aiming to characterize the extreme behavior possible in hydrodynamic models by analyzing the maximum growth of certain fundamental quantities. We consider here the rate of growth of the classical and fractional enstrophy in the fractional Burgers equation in the subcritical and supercritical regimes. Since solutions to this equation exhibit, respectively, globally well-posed behavior and finite-time blowup in these two regimes, this makes it a useful model to study the maximum instantaneous growth of enstrophy possible in these two distinct situations. First, we obtain estimates on the rates of growth and then show that these estimates are sharp up to numerical prefactors. This is done by numerically solving suitably defined constrained maximization problems and then demonstrating that for different values of the fractional dissipation exponent the obtained maximizers saturate the upper bounds in the estimates as the enstrophy increases. We conclude that the power-law dependence of the enstrophy rate of growth on the fractional dissipation exponent has the same global form in the subcritical, critical and parts of the supercritical regime. This indicates that the maximum enstrophy rate of growth changes smoothly as global well-posedness is lost when the fractional dissipation exponent attains supercritical values. In addition, nontrivial behavior is revealed for the maximum rate of growth of the fractional enstrophy obtained for small values of the fractional dissipation exponents. We also characterize the structure of the maximizers in different cases.

Maximum Likelihood and Restricted Likelihood Solutions in Multiple-Method Studies

PubMed Central

Rukhin, Andrew L.

2011-01-01

A formulation of the problem of combining data from several sources is discussed in terms of random effects models. The unknown measurement precision is assumed not to be the same for all methods. We investigate maximum likelihood solutions in this model. By representing the likelihood equations as simultaneous polynomial equations, the exact form of the Groebner basis for their stationary points is derived when there are two methods. A parametrization of these solutions which allows their comparison is suggested. A numerical method for solving likelihood equations is outlined, and an alternative to the maximum likelihood method, the restricted maximum likelihood, is studied. In the situation when methods variances are considered to be known an upper bound on the between-method variance is obtained. The relationship between likelihood equations and moment-type equations is also discussed. PMID:26989583

Characteristics of Plantar Loads in Maximum Forward Lunge Tasks in Badminton

PubMed Central

Hu, Xiaoyue; Li, Jing Xian; Hong, Youlian; Wang, Lin

2015-01-01

Background Badminton players often perform powerful and long-distance lunges during such competitive matches. The objective of this study is to compare the plantar loads of three one-step maximum forward lunges in badminton. Methods Fifteen right-handed male badminton players participated in the study. Each participant performed five successful maximum lunges at three directions. For each direction, the participant wore three different shoe brands. Plantar loading, including peak pressure, maximum force, and contact area, was measured by using an insole pressure measurement system. Two-way ANOVA with repeated measures was employed to determine the effects of the different lunge directions and different shoes, as well as the interaction of these two variables, on the measurements. Results The maximum force (MF) on the lateral midfoot was lower when performing left-forward lunges than when performing front-forward lunges (p = 0.006, 95% CI = −2.88 to −0.04%BW). The MF and peak pressures (PP) on the great toe region were lower for the front-forward lunge than for the right-forward lunge (MF, p = 0.047, 95% CI = −3.62 to −0.02%BW; PP, p = 0.048, 95% CI = −37.63 to −0.16 KPa) and left-forward lunge (MF, p = 0.015, 95% CI = −4.39 to −0.38%BW; PP, p = 0.008, 95% CI = −47.76 to −5.91 KPa). Conclusions These findings indicate that compared with the front-forward lunge, left and right maximum forward lunges induce greater plantar loads on the great toe region of the dominant leg of badminton players. The differences in the plantar loads of the different lunge directions may be potential risks for injuries to the lower extremities of badminton players. PMID:26367741

Maximum life spur gear design

NASA Technical Reports Server (NTRS)

Savage, M.; Mackulin, M. J.; Coe, H. H.; Coy, J. J.

1991-01-01

Optimization procedures allow one to design a spur gear reduction for maximum life and other end use criteria. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial guess values. The optimization algorithm is described, and the models for gear life and performance are presented. The algorithm is compact and has been programmed for execution on a desk top computer. Two examples are presented to illustrate the method and its application.

Designing Ground Antennas for Maximum G/T: Cassegrain or Gregorian?

NASA Technical Reports Server (NTRS)

Imbriale, William A.

2005-01-01

For optimum performance, a ground antenna system must maximize the ratio of received signal to the receiving system noise power, defined as the ratio of antenna gain to system-noise temperature (G/T). The total system noise temperature is the linear combination of the receiver noise temperature (including the feed system losses) and the antenna noise contribution. Hence, for very low noise cryogenic receiver systems, antenna noise-temperature properties are very significant contributors to G/T.It is well known that, for dual reflector systems designed for maximum gain, the gain performance of the antenna system is the same for both Cassegrain and Gregorian configurations. For a12-meter antenna designed to be part of the large array based Deep Space Network, a Cassegrain configuration designed for maximum G/T at X-band was 0.7 dB higher than the equivalent Gregorian configuration. This study demonstrates that, for maximum GIT, the dual shaped Cassegrain design is always better than the Gregorian.

Reliability of the Load-Velocity Relationship Obtained Through Linear and Polynomial Regression Models to Predict the One-Repetition Maximum Load.

PubMed

Pestaña-Melero, Francisco Luis; Haff, G Gregory; Rojas, Francisco Javier; Pérez-Castilla, Alejandro; García-Ramos, Amador

2017-12-18

This study aimed to compare the between-session reliability of the load-velocity relationship between (1) linear vs. polynomial regression models, (2) concentric-only vs. eccentric-concentric bench press variants, as well as (3) the within-participants vs. the between-participants variability of the velocity attained at each percentage of the one-repetition maximum (%1RM). The load-velocity relationship of 30 men (age: 21.2±3.8 y; height: 1.78±0.07 m, body mass: 72.3±7.3 kg; bench press 1RM: 78.8±13.2 kg) were evaluated by means of linear and polynomial regression models in the concentric-only and eccentric-concentric bench press variants in a Smith Machine. Two sessions were performed with each bench press variant. The main findings were: (1) first-order-polynomials (CV: 4.39%-4.70%) provided the load-velocity relationship with higher reliability than second-order-polynomials (CV: 4.68%-5.04%); (2) the reliability of the load-velocity relationship did not differ between the concentric-only and eccentric-concentric bench press variants; (3) the within-participants variability of the velocity attained at each %1RM was markedly lower than the between-participants variability. Taken together, these results highlight that, regardless of the bench press variant considered, the individual determination of the load-velocity relationship by a linear regression model could be recommended to monitor and prescribe the relative load in the Smith machine bench press exercise.

Post optimization paradigm in maximum 3-satisfiability logic programming

NASA Astrophysics Data System (ADS)

Mansor, Mohd. Asyraf; Sathasivam, Saratha; Kasihmuddin, Mohd Shareduwan Mohd

2017-08-01

Maximum 3-Satisfiability (MAX-3SAT) is a counterpart of the Boolean satisfiability problem that can be treated as a constraint optimization problem. It deals with a conundrum of searching the maximum number of satisfied clauses in a particular 3-SAT formula. This paper presents the implementation of enhanced Hopfield network in hastening the Maximum 3-Satisfiability (MAX-3SAT) logic programming. Four post optimization techniques are investigated, including the Elliot symmetric activation function, Gaussian activation function, Wavelet activation function and Hyperbolic tangent activation function. The performances of these post optimization techniques in accelerating MAX-3SAT logic programming will be discussed in terms of the ratio of maximum satisfied clauses, Hamming distance and the computation time. Dev-C++ was used as the platform for training, testing and validating our proposed techniques. The results depict the Hyperbolic tangent activation function and Elliot symmetric activation function can be used in doing MAX-3SAT logic programming.

Maximum and minimum entropy states yielding local continuity bounds

NASA Astrophysics Data System (ADS)

Hanson, Eric P.; Datta, Nilanjana

2018-04-01

Given an arbitrary quantum state (σ), we obtain an explicit construction of a state ρɛ * ( σ ) [respectively, ρ * , ɛ ( σ ) ] which has the maximum (respectively, minimum) entropy among all states which lie in a specified neighborhood (ɛ-ball) of σ. Computing the entropy of these states leads to a local strengthening of the continuity bound of the von Neumann entropy, i.e., the Audenaert-Fannes inequality. Our bound is local in the sense that it depends on the spectrum of σ. The states ρɛ * ( σ ) and ρ * , ɛ (σ) depend only on the geometry of the ɛ-ball and are in fact optimizers for a larger class of entropies. These include the Rényi entropy and the minimum- and maximum-entropies, providing explicit formulas for certain smoothed quantities. This allows us to obtain local continuity bounds for these quantities as well. In obtaining this bound, we first derive a more general result which may be of independent interest, namely, a necessary and sufficient condition under which a state maximizes a concave and Gâteaux-differentiable function in an ɛ-ball around a given state σ. Examples of such a function include the von Neumann entropy and the conditional entropy of bipartite states. Our proofs employ tools from the theory of convex optimization under non-differentiable constraints, in particular Fermat's rule, and majorization theory.

Maximum height and minimum time vertical jumping.

PubMed

Domire, Zachary J; Challis, John H

2015-08-20

The performance criterion in maximum vertical jumping has typically been assumed to simply raise the center of mass as high as possible. In many sporting activities minimizing movement time during the jump is likely also critical to successful performance. The purpose of this study was to examine maximum height jumps performed while minimizing jump time. A direct dynamics model was used to examine squat jump performance, with dual performance criteria: maximize jump height and minimize jump time. The muscle model had activation dynamics, force-length, force-velocity properties, and a series of elastic component representing the tendon. The simulations were run in two modes. In Mode 1 the model was placed in a fixed initial position. In Mode 2 the simulation model selected the initial squat configuration as well as the sequence of muscle activations. The inclusion of time as a factor in Mode 1 simulations resulted in a small decrease in jump height and moderate time savings. The improvement in time was mostly accomplished by taking off from a less extended position. In Mode 2 simulations, more substantial time savings could be achieved by beginning the jump in a more upright posture. However, when time was weighted more heavily in these simulations, there was a more substantial reduction in jump height. Future work is needed to examine the implications for countermovement jumping and to examine the possibility of minimizing movement time as part of the control scheme even when the task is to jump maximally. Copyright © 2015 Elsevier Ltd. All rights reserved.

GNSS Spoofing Detection and Mitigation Based on Maximum Likelihood Estimation.

PubMed

Wang, Fei; Li, Hong; Lu, Mingquan

2017-06-30

Spoofing attacks are threatening the global navigation satellite system (GNSS). The maximum likelihood estimation (MLE)-based positioning technique is a direct positioning method originally developed for multipath rejection and weak signal processing. We find this method also has a potential ability for GNSS anti-spoofing since a spoofing attack that misleads the positioning and timing result will cause distortion to the MLE cost function. Based on the method, an estimation-cancellation approach is presented to detect spoofing attacks and recover the navigation solution. A statistic is derived for spoofing detection with the principle of the generalized likelihood ratio test (GLRT). Then, the MLE cost function is decomposed to further validate whether the navigation solution obtained by MLE-based positioning is formed by consistent signals. Both formulae and simulations are provided to evaluate the anti-spoofing performance. Experiments with recordings in real GNSS spoofing scenarios are also performed to validate the practicability of the approach. Results show that the method works even when the code phase differences between the spoofing and authentic signals are much less than one code chip, which can improve the availability of GNSS service greatly under spoofing attacks.

GNSS Spoofing Detection and Mitigation Based on Maximum Likelihood Estimation

PubMed Central

Li, Hong; Lu, Mingquan

2017-01-01

Spoofing attacks are threatening the global navigation satellite system (GNSS). The maximum likelihood estimation (MLE)-based positioning technique is a direct positioning method originally developed for multipath rejection and weak signal processing. We find this method also has a potential ability for GNSS anti-spoofing since a spoofing attack that misleads the positioning and timing result will cause distortion to the MLE cost function. Based on the method, an estimation-cancellation approach is presented to detect spoofing attacks and recover the navigation solution. A statistic is derived for spoofing detection with the principle of the generalized likelihood ratio test (GLRT). Then, the MLE cost function is decomposed to further validate whether the navigation solution obtained by MLE-based positioning is formed by consistent signals. Both formulae and simulations are provided to evaluate the anti-spoofing performance. Experiments with recordings in real GNSS spoofing scenarios are also performed to validate the practicability of the approach. Results show that the method works even when the code phase differences between the spoofing and authentic signals are much less than one code chip, which can improve the availability of GNSS service greatly under spoofing attacks. PMID:28665318

Performance of Axial-Flow Supersonic Compressor on XJ-55-FF-1 Turbojet Engine. I - Preliminary Performance of Compressor. 1; Preliminary Performance of Compressor

NASA Technical Reports Server (NTRS)

Hartmann, Melvin J.; Graham, Robert C.

1949-01-01

An investigation was conducted to determine the performance characteristics of the axial-flow supersonic compressor of the XJ-55-FF-1 turbo Jet engine. The test unit consisted of a row of inlet guide vanes and a supersonic rotor; the stator vanes after the rotor were omitted. The maximum pressure ratio produced in the single stage was 2.28 at an equivalent tip speed or 1814 feet per second with an adiabatic efficiency of approximately 0.61, equivalent weight flow of 13.4 pounds per second. The maximum efficiency of 0.79 was obtained at an equivalent tip speed of 801 feet per second.

Neural Modeling of Fuzzy Controllers for Maximum Power Point Tracking in Photovoltaic Energy Systems

NASA Astrophysics Data System (ADS)

Lopez-Guede, Jose Manuel; Ramos-Hernanz, Josean; Altın, Necmi; Ozdemir, Saban; Kurt, Erol; Azkune, Gorka

2018-06-01

One field in which electronic materials have an important role is energy generation, especially within the scope of photovoltaic energy. This paper deals with one of the most relevant enabling technologies within that scope, i.e, the algorithms for maximum power point tracking implemented in the direct current to direct current converters and its modeling through artificial neural networks (ANNs). More specifically, as a proof of concept, we have addressed the problem of modeling a fuzzy logic controller that has shown its performance in previous works, and more specifically the dimensionless duty cycle signal that controls a quadratic boost converter. We achieved a very accurate model since the obtained medium squared error is 3.47 × 10-6, the maximum error is 16.32 × 10-3 and the regression coefficient R is 0.99992, all for the test dataset. This neural implementation has obvious advantages such as a higher fault tolerance and a simpler implementation, dispensing with all the complex elements needed to run a fuzzy controller (fuzzifier, defuzzifier, inference engine and knowledge base) because, ultimately, ANNs are sums and products.

Efficient reliability analysis of structures with the rotational quasi-symmetric point- and the maximum entropy methods

NASA Astrophysics Data System (ADS)

Xu, Jun; Dang, Chao; Kong, Fan

2017-10-01

This paper presents a new method for efficient structural reliability analysis. In this method, a rotational quasi-symmetric point method (RQ-SPM) is proposed for evaluating the fractional moments of the performance function. Then, the derivation of the performance function's probability density function (PDF) is carried out based on the maximum entropy method in which constraints are specified in terms of fractional moments. In this regard, the probability of failure can be obtained by a simple integral over the performance function's PDF. Six examples, including a finite element-based reliability analysis and a dynamic system with strong nonlinearity, are used to illustrate the efficacy of the proposed method. All the computed results are compared with those by Monte Carlo simulation (MCS). It is found that the proposed method can provide very accurate results with low computational effort.

Evaluation of the Maximum Allowable Cost Program

PubMed Central

Lee, A. James; Hefner, Dennis; Dobson, Allen; Hardy, Ralph

1983-01-01

This article summarizes an evaluation of the Maximum Allowable Cost (MAC)-Estimated Acquisition Cost (EAC) program, the Federal Government's cost-containment program for prescription drugs.1 The MAC-EAC regulations which became effective on August 26, 1976, have four major components: (1) Maximum Allowable Cost reimbursement limits for selected multisource or generically available drugs; (2) Estimated Acquisition Cost reimbursement limits for all drugs; (3) “usual and customary” reimbursement limits for all drugs; and (4) a directive that professional fee studies be performed by each State. The study examines the benefits and costs of the MAC reimbursement limits for 15 dosage forms of five multisource drugs and EAC reimbursement limits for all drugs for five selected States as of 1979. PMID:10309857

Performance Analysis and Discussion on the Thermoelectric Element Footprint for PV-TE Maximum Power Generation

NASA Astrophysics Data System (ADS)

Li, Guiqiang; Zhao, Xudong; Jin, Yi; Chen, Xiao; Ji, Jie; Shittu, Samson

2018-06-01

Geometrical optimisation is a valuable way to improve the efficiency of a thermoelectric element (TE). In a hybrid photovoltaic-thermoelectric (PV-TE) system, the photovoltaic (PV) and thermoelectric (TE) components have a relatively complex relationship; their individual effects mean that geometrical optimisation of the TE element alone may not be sufficient to optimize the entire PV-TE hybrid system. In this paper, we introduce a parametric optimisation of the geometry of the thermoelectric element footprint for a PV-TE system. A uni-couple TE model was built for the PV-TE using the finite element method and temperature-dependent thermoelectric material properties. Two types of PV cells were investigated in this paper and the performance of PV-TE with different lengths of TE elements and different footprint areas was analysed. The outcome showed that no matter the TE element's length and the footprint areas, the maximum power output occurs when A n /A p = 1. This finding is useful, as it provides a reference whenever PV-TE optimisation is investigated.

Prompt merger collapse and the maximum mass of neutron stars.

PubMed

Bauswein, A; Baumgarte, T W; Janka, H-T

2013-09-27

We perform hydrodynamical simulations of neutron-star mergers for a large sample of temperature-dependent nuclear equations of state and determine the threshold mass above which the merger remnant promptly collapses to form a black hole. We find that, depending on the equation of state, the threshold mass is larger than the maximum mass of a nonrotating star in isolation by between 30 and 70 percent. Our simulations also show that the ratio between the threshold mass and maximum mass is tightly correlated with the compactness of the nonrotating maximum-mass configuration. We speculate on how this relation can be used to derive constraints on neutron-star properties from future observations.

Evaluation of probable maximum snow accumulation: Development of a methodology for climate change studies

NASA Astrophysics Data System (ADS)

Klein, Iris M.; Rousseau, Alain N.; Frigon, Anne; Freudiger, Daphné; Gagnon, Patrick

2016-06-01

Probable maximum snow accumulation (PMSA) is one of the key variables used to estimate the spring probable maximum flood (PMF). A robust methodology for evaluating the PMSA is imperative so the ensuing spring PMF is a reasonable estimation. This is of particular importance in times of climate change (CC) since it is known that solid precipitation in Nordic landscapes will in all likelihood change over the next century. In this paper, a PMSA methodology based on simulated data from regional climate models is developed. Moisture maximization represents the core concept of the proposed methodology; precipitable water being the key variable. Results of stationarity tests indicate that CC will affect the monthly maximum precipitable water and, thus, the ensuing ratio to maximize important snowfall events. Therefore, a non-stationary approach is used to describe the monthly maximum precipitable water. Outputs from three simulations produced by the Canadian Regional Climate Model were used to give first estimates of potential PMSA changes for southern Quebec, Canada. A sensitivity analysis of the computed PMSA was performed with respect to the number of time-steps used (so-called snowstorm duration) and the threshold for a snowstorm to be maximized or not. The developed methodology is robust and a powerful tool to estimate the relative change of the PMSA. Absolute results are in the same order of magnitude as those obtained with the traditional method and observed data; but are also found to depend strongly on the climate projection used and show spatial variability.

Assessment of the maximum voluntary arm muscle contraction in sign language for the deaf.

PubMed

Regalo, S C H; Teixeira, V R; Vitti, M; Chaves, T C; Hallak, J E C; Bevilaqua-Grossi, D; Siriani de Oliveira, A

2006-01-01

The purpose of this study was to investigate the levels of upper member muscles' activation of deaf individuals, who use the Brazilian sign language - LIBRAS, comparing these findings to volunteers with no postural deviations and normal hearing Forty eight volunteers divided into two groups comprising healthy and deaf subjects (24 volunteers for each group). The signs of rest were obtained with the volunteer maintaining the upper member in an anatomical position, but with the forearm flexed and sustained by the lower member. Maximum voluntary isometric contractions (MVIC) of the biceps, triceps, deltoid, and trapezius muscles were performed in the position of muscular function testing. Statistical analysis was performed using the SPSS-10.0. Continuous data with normal distribution were analyzed by ANOVA with the significance level of p < 0.01. The normalized electromyographic muscle data obtained in muscular rest do not show statistically significant differences among the studies muscles, in both groups. In the comparison of normalized RMS values obtained in MVIC, the mean values for the trapezius muscle of deaf group were statistically lower than control group. This study's results indicate there are no differences between the levels of muscular activation for arm biceps, arm triceps, and the anterior portion of the deltoid muscle between the mean normalized RMS values of deaf and healthy individuals.

An evaluation of several different classification schemes - Their parameters and performance. [maximum likelihood decision for crop identification

NASA Technical Reports Server (NTRS)

Scholz, D.; Fuhs, N.; Hixson, M.

1979-01-01

The overall objective of this study was to apply and evaluate several of the currently available classification schemes for crop identification. The approaches examined were: (1) a per point Gaussian maximum likelihood classifier, (2) a per point sum of normal densities classifier, (3) a per point linear classifier, (4) a per point Gaussian maximum likelihood decision tree classifier, and (5) a texture sensitive per field Gaussian maximum likelihood classifier. Three agricultural data sets were used in the study: areas from Fayette County, Illinois, and Pottawattamie and Shelby Counties in Iowa. The segments were located in two distinct regions of the Corn Belt to sample variability in soils, climate, and agricultural practices.

Maximum entropy, fluctuations and priors

NASA Astrophysics Data System (ADS)

Caticha, A.

2001-05-01

The method of maximum entropy (ME) is extended to address the following problem: Once one accepts that the ME distribution is to be preferred over all others, the question is to what extent are distributions with lower entropy supposed to be ruled out. Two applications are given. The first is to the theory of thermodynamic fluctuations. The formulation is exact, covariant under changes of coordinates, and allows fluctuations of both the extensive and the conjugate intensive variables. The second application is to the construction of an objective prior for Bayesian inference. The prior obtained by following the ME method to its inevitable conclusion turns out to be a special case (α=1) of what are currently known under the name of entropic priors. .

Statistical inference based on the nonparametric maximum likelihood estimator under double-truncation.

PubMed

Emura, Takeshi; Konno, Yoshihiko; Michimae, Hirofumi

2015-07-01

Doubly truncated data consist of samples whose observed values fall between the right- and left- truncation limits. With such samples, the distribution function of interest is estimated using the nonparametric maximum likelihood estimator (NPMLE) that is obtained through a self-consistency algorithm. Owing to the complicated asymptotic distribution of the NPMLE, the bootstrap method has been suggested for statistical inference. This paper proposes a closed-form estimator for the asymptotic covariance function of the NPMLE, which is computationally attractive alternative to bootstrapping. Furthermore, we develop various statistical inference procedures, such as confidence interval, goodness-of-fit tests, and confidence bands to demonstrate the usefulness of the proposed covariance estimator. Simulations are performed to compare the proposed method with both the bootstrap and jackknife methods. The methods are illustrated using the childhood cancer dataset.

The estimation of probable maximum precipitation: the case of Catalonia.

PubMed

Casas, M Carmen; Rodríguez, Raül; Nieto, Raquel; Redaño, Angel

2008-12-01

A brief overview of the different techniques used to estimate the probable maximum precipitation (PMP) is presented. As a particular case, the 1-day PMP over Catalonia has been calculated and mapped with a high spatial resolution. For this purpose, the annual maximum daily rainfall series from 145 pluviometric stations of the Instituto Nacional de Meteorología (Spanish Weather Service) in Catalonia have been analyzed. In order to obtain values of PMP, an enveloping frequency factor curve based on the actual rainfall data of stations in the region has been developed. This enveloping curve has been used to estimate 1-day PMP values of all the 145 stations. Applying the Cressman method, the spatial analysis of these values has been achieved. Monthly precipitation climatological data, obtained from the application of Geographic Information Systems techniques, have been used as the initial field for the analysis. The 1-day PMP at 1 km(2) spatial resolution over Catalonia has been objectively determined, varying from 200 to 550 mm. Structures with wavelength longer than approximately 35 km can be identified and, despite their general concordance, the obtained 1-day PMP spatial distribution shows remarkable differences compared to the annual mean precipitation arrangement over Catalonia.

Path Finding for Maximum Value of Information in Multi-Modal Underwater Wireless Sensor Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gjanci, Petrika; Petrioli, Chiara; Basagni, Stefano

Here, we consider underwater multi-modal wireless sensor networks (UWSNs) suitable for applications on submarine surveillance and monitoring, where nodes offload data to a mobile autonomous underwater vehicle (AUV) via optical technology, and coordinate using acoustic communication. Sensed data are associated with a value, decaying in time. In this scenario, we address the problem of finding the path of the AUV so that the Value of Information (VoI) of the data delivered to a sink on the surface is maximized. We define a Greedy and Adaptive AUV Path-finding (GAAP) heuristic that drives the AUV to collect data from nodes depending onmore » the VoI of their data. For benchmarking the performance of AUV path-finding heuristics, we define an integer linear programming (ILP) formulation that accurately models the considered scenario, deriving a path that drives the AUV to collect and deliver data with the maximum VoI. In our experiments GAAP consistently delivers more than 80 percent of the theoretical maximum VoI determined by the ILP model. We also compare the performance of GAAP with that of other strategies for driving the AUV among sensing nodes, namely, random paths, TSP-based paths and a “lawn mower”-like strategy. Our results show that GAAP always outperforms every other heuristic in terms of delivered VoI, also obtaining higher energy efficiency.« less

Path Finding for Maximum Value of Information in Multi-Modal Underwater Wireless Sensor Networks

DOE PAGES

Gjanci, Petrika; Petrioli, Chiara; Basagni, Stefano; ...

2017-05-19

Here, we consider underwater multi-modal wireless sensor networks (UWSNs) suitable for applications on submarine surveillance and monitoring, where nodes offload data to a mobile autonomous underwater vehicle (AUV) via optical technology, and coordinate using acoustic communication. Sensed data are associated with a value, decaying in time. In this scenario, we address the problem of finding the path of the AUV so that the Value of Information (VoI) of the data delivered to a sink on the surface is maximized. We define a Greedy and Adaptive AUV Path-finding (GAAP) heuristic that drives the AUV to collect data from nodes depending onmore » the VoI of their data. For benchmarking the performance of AUV path-finding heuristics, we define an integer linear programming (ILP) formulation that accurately models the considered scenario, deriving a path that drives the AUV to collect and deliver data with the maximum VoI. In our experiments GAAP consistently delivers more than 80 percent of the theoretical maximum VoI determined by the ILP model. We also compare the performance of GAAP with that of other strategies for driving the AUV among sensing nodes, namely, random paths, TSP-based paths and a “lawn mower”-like strategy. Our results show that GAAP always outperforms every other heuristic in terms of delivered VoI, also obtaining higher energy efficiency.« less

Analysis and Evaluation of Parameters Determining Maximum Efficiency of Fish Protection

NASA Astrophysics Data System (ADS)

Khetsuriani, E. D.; Kostyukov, V. P.; Khetsuriani, T. E.

2017-11-01

The article is concerned with experimental research findings. The efficiency of fish fry protection from entering water inlets is the main criterion of any fish protection facility or device. The research was aimed to determine an adequate mathematical model E = f(PCT, Vp, α), where PCT, Vp and α are controlled factors influencing the process of fish fry protection. The result of the processing of experimental data was an adequate regression model. We determined the maximum of fish protection Emax=94,21 and the minimum of optimization function Emin=44,41. As a result of the statistical processing of experimental data we obtained adequate dependences for determining an optimal rotational speed of tip and fish protection efficiency. The analysis of fish protection efficiency dependence E% = f(PCT, Vp, α) allowed the authors to recommend the following optimized operating modes for it: the maximum fish protection efficiency is achieved at the process pressure PCT=3 atm, stream velocity Vp=0,42 m/s and nozzle inclination angle α=47°49’. The stream velocity Vp has the most critical influence on fish protection efficiency. The maximum efficiency of fish protection is obtained at the tip rotational speed of 70.92 rpm.

The effect of crystal shape, size and bimodality on the maximum packing and the rheology of crystal bearing magma

NASA Astrophysics Data System (ADS)

Moitra, Pranabendu; Gonnermann, Helge

2014-05-01

Magma often contains crystals of various shapes and sizes. We present experimental results on the effect of the shape- and size-distribution of solid particles on the rheological properties of solid-liquid suspensions, which are hydrodynamically analogous to crystal-bearing magmas. The suspensions were comprised of either a single particle shape and size (unimodal) or a mixture of two different particle shapes and sizes (bimodal). For each type of suspension we characterized the dry maximum packing fraction of the particle mixture using the tap density method. We then systematically varied the total volume fraction of particles in the suspension, as well as the relative proportion of the two different particle types in the bimodal suspensions. For each of the resultant mixtures (suspensions) we performed controlled shear stress experiments using a rotational rheometer in parallel-plate geometry spanning 4 orders of magnitude in shear stress. The resultant data curves of shear stress as a function of shear rate were fitted using a Herschel-Bulkley rheological model. We find that the dry maximum packing decreases with increasing particle aspect ratio (ar) and decreasing particle size ratio (Λ). The highest dry maximum packing was obtained at 60-75% volume of larger particles for bimodal spherical particle mixture. Normalized consistency, Kr, defined as the ratio of the consistency of the suspension and the viscosity of the suspending liquid, was fitted using a Krieger-Dougherty model as a function of the total solid volume fraction (φ). The maximum packing fractions (φm) obtained from the shear experimental data fitting of the unimodal suspensions were similar in magnitude with the dry maximum packing fractions of the unimodal particles. Subsequently, we used the dry maximum packing fractions of the bimodal particle mixtures to fit Kr as a function of φ for the bimodal suspensions. We find that Kr increases rapidly for suspensions with larger ar and smaller �

Efficiency at maximum power output of linear irreversible Carnot-like heat engines.

PubMed

Wang, Yang; Tu, Z C

2012-01-01

The efficiency at maximum power output of linear irreversible Carnot-like heat engines is investigated based on the assumption that the rate of irreversible entropy production of the working substance in each "isothermal" process is a quadratic form of the heat exchange rate between the working substance and the reservoir. It is found that the maximum power output corresponds to minimizing the irreversible entropy production in two isothermal processes of the Carnot-like cycle, and that the efficiency at maximum power output has the form η(mP)=η(C)/(2-γη(C)), where η(C) is the Carnot efficiency, while γ depends on the heat transfer coefficients between the working substance and two reservoirs. The value of η(mP) is bounded between η(-)≡η(C)/2 and η(+)≡η(C)/(2-η(C)). These results are consistent with those obtained by Chen and Yan [J. Chem. Phys. 90, 3740 (1989)] based on the endoreversible assumption, those obtained by Esposito et al. [Phys. Rev. Lett. 105, 150603 (2010)] based on the low-dissipation assumption, and those obtained by Schmiedl and Seifert [Europhys. Lett. 81, 20003 (2008)] for stochastic heat engines which in fact also satisfy the low-dissipation assumption. Additionally, we find that the endoreversible assumption happens to hold for Carnot-like heat engines operating at the maximum power output based on our fundamental assumption, and that the Carnot-like heat engines that we focused on do not strictly satisfy the low-dissipation assumption, which implies that the low-dissipation assumption or our fundamental assumption is a sufficient but non-necessary condition for the validity of η(mP)=η(C)/(2-γη(C)) as well as the existence of two bounds, η(-)≡η(C)/2 and η(+)≡η(C)/(2-η(C)). © 2012 American Physical Society

On Parallel Push-Relabel based Algorithms for Bipartite Maximum Matching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langguth, Johannes; Azad, Md Ariful; Halappanavar, Mahantesh

2014-07-01

We study multithreaded push-relabel based algorithms for computing maximum cardinality matching in bipartite graphs. Matching is a fundamental combinatorial (graph) problem with applications in a wide variety of problems in science and engineering. We are motivated by its use in the context of sparse linear solvers for computing maximum transversal of a matrix. We implement and test our algorithms on several multi-socket multicore systems and compare their performance to state-of-the-art augmenting path-based serial and parallel algorithms using a testset comprised of a wide range of real-world instances. Building on several heuristics for enhancing performance, we demonstrate good scaling for themore » parallel push-relabel algorithm. We show that it is comparable to the best augmenting path-based algorithms for bipartite matching. To the best of our knowledge, this is the first extensive study of multithreaded push-relabel based algorithms. In addition to a direct impact on the applications using matching, the proposed algorithmic techniques can be extended to preflow-push based algorithms for computing maximum flow in graphs.« less

Jarzynski equality in the context of maximum path entropy

NASA Astrophysics Data System (ADS)

González, Diego; Davis, Sergio

2017-06-01

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

Using maximum topology matching to explore differences in species distribution models

USGS Publications Warehouse

Poco, Jorge; Doraiswamy, Harish; Talbert, Marian; Morisette, Jeffrey; Silva, Claudio

2015-01-01

Species distribution models (SDM) are used to help understand what drives the distribution of various plant and animal species. These models are typically high dimensional scalar functions, where the dimensions of the domain correspond to predictor variables of the model algorithm. Understanding and exploring the differences between models help ecologists understand areas where their data or understanding of the system is incomplete and will help guide further investigation in these regions. These differences can also indicate an important source of model to model uncertainty. However, it is cumbersome and often impractical to perform this analysis using existing tools, which allows for manual exploration of the models usually as 1-dimensional curves. In this paper, we propose a topology-based framework to help ecologists explore the differences in various SDMs directly in the high dimensional domain. In order to accomplish this, we introduce the concept of maximum topology matching that computes a locality-aware correspondence between similar extrema of two scalar functions. The matching is then used to compute the similarity between two functions. We also design a visualization interface that allows ecologists to explore SDMs using their topological features and to study the differences between pairs of models found using maximum topological matching. We demonstrate the utility of the proposed framework through several use cases using different data sets and report the feedback obtained from ecologists.

The maximum growth rate of life on Earth

NASA Astrophysics Data System (ADS)

Corkrey, Ross; McMeekin, Tom A.; Bowman, John P.; Olley, June; Ratkowsky, David

2018-01-01

Life on Earth spans a range of temperatures and exhibits biological growth rates that are temperature dependent. While the observation that growth rates are temperature dependent is well known, we have recently shown that the statistical distribution of specific growth rates for life on Earth is a function of temperature (Corkrey et al., 2016). The maximum rates of growth of all life have a distinct limit, even when grown under optimal conditions, and which vary predictably with temperature. We term this distribution of growth rates the biokinetic spectrum for temperature (BKST). The BKST possibly arises from a trade-off between catalytic activity and stability of enzymes involved in a rate-limiting Master Reaction System (MRS) within the cell. We develop a method to extrapolate quantile curves for the BKST to obtain the posterior probability of the maximum rate of growth of any form of life on Earth. The maximum rate curve conforms to the observed data except below 0°C and above 100°C where the predicted value may be positively biased. The deviation below 0°C may arise from the bulk properties of water, while the degradation of biomolecules may be important above 100°C. The BKST has potential application in astrobiology by providing an estimate of the maximum possible growth rate attainable by terrestrial life and perhaps life elsewhere. We suggest that the area under the maximum growth rate curve and the peak rate may be useful characteristics in considerations of habitability. The BKST can serve as a diagnostic for unusual life, such as second biogenesis or non-terrestrial life. Since the MRS must have been heavily conserved the BKST may contain evolutionary relics. The BKST can serve as a signature summarizing the nature of life in environments beyond Earth, or to characterize species arising from a second biogenesis on Earth.

Approximate maximum likelihood decoding of block codes

NASA Technical Reports Server (NTRS)

Greenberger, H. J.

1979-01-01

Approximate maximum likelihood decoding algorithms, based upon selecting a small set of candidate code words with the aid of the estimated probability of error of each received symbol, can give performance close to optimum with a reasonable amount of computation. By combining the best features of various algorithms and taking care to perform each step as efficiently as possible, a decoding scheme was developed which can decode codes which have better performance than those presently in use and yet not require an unreasonable amount of computation. The discussion of the details and tradeoffs of presently known efficient optimum and near optimum decoding algorithms leads, naturally, to the one which embodies the best features of all of them.

Maximum entropy principal for transportation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bilich, F.; Da Silva, R.

In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utilitymore » concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.« less

Maximum Entropy Principle for Transportation

NASA Astrophysics Data System (ADS)

Bilich, F.; DaSilva, R.

2008-11-01

In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.

A Comparison of a Maximum Exertion Method and a Model-Based, Sub-Maximum Exertion Method for Normalizing Trunk EMG

PubMed Central

Cholewicki, Jacek; van Dieën, Jaap; Lee, Angela S.; Reeves, N. Peter

2011-01-01

The problem with normalizing EMG data from patients with painful symptoms (e.g. low back pain) is that such patients may be unwilling or unable to perform maximum exertions. Furthermore, the normalization to a reference signal, obtained from a maximal or sub-maximal task, tends to mask differences that might exist as a result of pathology. Therefore, we presented a novel method (GAIN method) for normalizing trunk EMG data that overcomes both problems. The GAIN method does not require maximal exertions (MVC) and tends to preserve distinct features in the muscle recruitment patterns for various tasks. Ten healthy subjects performed various isometric trunk exertions, while EMG data from 10 muscles were recorded and later normalized using the GAIN and MVC methods. The MVC method resulted in smaller variation between subjects when tasks were executed at the three relative force levels (10%, 20%, and 30% MVC), while the GAIN method resulted in smaller variation between subjects when the tasks were executed at the three absolute force levels (50 N, 100 N, and 145 N). This outcome implies that the MVC method provides a relative measure of muscle effort, while the GAIN-normalized EMG data gives an estimate of the absolute muscle force. Therefore, the GAIN-normalized EMG data tends to preserve the EMG differences between subjects in the way they recruit their muscles to execute various tasks, while the MVC-normalized data will tend to suppress such differences. The appropriate choice of the EMG normalization method will depend on the specific question that an experimenter is attempting to answer. PMID:21665489

Investigation of Maximum Blade Loading Capability of Lift-Offset Rotors

NASA Technical Reports Server (NTRS)

Yeo, Hyeonsoo; Johnson, Wayne

2013-01-01

Maximum blade loading capability of a coaxial, lift-offset rotor is investigated using a rotorcraft configuration designed in the context of short-haul, medium-size civil and military missions. The aircraft was sized for a 6600-lb payload and a range of 300 nm. The rotor planform and twist were optimized for hover and cruise performance. For the present rotor performance calculations, the collective pitch angle is progressively increased up to and through stall with the shaft angle set to zero. The effects of lift offset on rotor lift, power, controls, and blade airloads and structural loads are examined. The maximum lift capability of the coaxial rotor increases as lift offset increases and extends well beyond the McHugh lift boundary as the lift potential of the advancing blades are fully realized. A parametric study is conducted to examine the differences between the present coaxial rotor and the McHugh rotor in terms of maximum lift capabilities and to identify important design parameters that define the maximum lift capability of the rotor. The effects of lift offset on rotor blade airloads and structural loads are also investigated. Flap bending moment increases substantially as lift offset increases to carry the hub roll moment even at low collective values. The magnitude of flap bending moment is dictated by the lift-offset value (hub roll moment) but is less sensitive to collective and speed.

Perturbative expansion for the maximum of fractional Brownian motion.

PubMed

Delorme, Mathieu; Wiese, Kay Jörg

2016-07-01

Brownian motion is the only random process which is Gaussian, scale invariant, and Markovian. Dropping the Markovian property, i.e., allowing for memory, one obtains a class of processes called fractional Brownian motion, indexed by the Hurst exponent H. For H=1/2, Brownian motion is recovered. We develop a perturbative approach to treat the nonlocality in time in an expansion in ɛ=H-1/2. This allows us to derive analytic results beyond scaling exponents for various observables related to extreme value statistics: the maximum m of the process and the time t_{max} at which this maximum is reached, as well as their joint distribution. We test our analytical predictions with extensive numerical simulations for different values of H. They show excellent agreement, even for H far from 1/2.

Energetic Phenomena on the Sun: The Solar Maximum Mission Flare Workshop. Proceedings

NASA Technical Reports Server (NTRS)

Kundu, Mukul (Editor); Woodgate, Bruce (Editor)

1986-01-01

The general objectives of the conference were as follows: (1) Synthesize flare studies after three years of Solar Maximum Mission (SSM) data analysis. Encourage a broader participation in the SMM data analysis and combine this more fully with theory and other data sources-data obtained with other spacecraft such as the HINOTORI, p78-1, and ISEE-3 spacecrafts, and with the Very Large Array (VLA) and many other ground-based instruments. Many coordinated data sets, unprecedented in their breadth of coverage and multiplicity of sources, had been obtained within the structure of the Solar Maximum Year (SMY). (2) Stimulate joint studies, and publication in the general scientific literature. The intended primary benefit was for informal collaborations to be started or broadened at the Workshops with subsequent publications. (3) Provide a special publication resulting from the Workshop.

The evaluation of maximum horizontal in-situ stress using the wellbore imagers data

NASA Astrophysics Data System (ADS)

Dubinya, N. V.; Ezhov, K. A.

2016-12-01

Well drilling provides a number of possibilities to improve the knowledge of stress state of the upper layers of the Earth crust. The data obtained from drilling, well logging, core experiments and special tests is used to evaluate the principal stresses' directions and magnitudes. Although the values of vertical stress and minimum horizontal stress may be decently estimated, the maximum horizontal stress remains a major problem. In this study a new method to estimate this value is proposed. The suggested approach is based on the concept of hydraulically conductive and non-conductive fractures near a wellbore (Barton, Zoback and Moos, 1995). It was stated that all the fractures which properties may be acquired from well logging data can be divided into two groups regarding hydraulic conductivity. The fracture properties and the in-situ stress state are put in relationship via the Mohr diagram. This approach was later used by Ito and Zoback (2000) to estimate the magnitude of the maximum horizontal stress from the temperature profiles. In the current study ultrasonic and resistivity borehole imaging are used to estimate the magnitude of maximum horizontal stress in rather precise way. After proper interpretation one is able to obtain orientation and hydraulic conductivity for each fracture appeared at the images. If the proper profiles of vertical and minimum horizontal stresses are known all the fractures may be analyzed at the Mohr diagram. Alteration of maximum horizontal stress profile grants an opportunity to adjust it so the conductive fractures at the Mohr diagram fit the data from imagers' interpretation. The precision of the suggested approach was evaluated for several oil production wells in Siberia with decent wellbore stability models. It appeared that the difference between maximum horizontal stress estimated in a suggested approach and the values obtained from drilling reports did not exceed 0.5 MPa. Thus the proposed approach may be used to evaluate

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

PubMed Central

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

2016-01-01

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

20 CFR 228.14 - Family maximum.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Family maximum. 228.14 Section 228.14... SURVIVOR ANNUITIES The Tier I Annuity Component § 228.14 Family maximum. (a) Family maximum defined. Under... person's earnings record is limited. This limited amount is called the family maximum. The family maximum...

20 CFR 228.14 - Family maximum.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Family maximum. 228.14 Section 228.14... SURVIVOR ANNUITIES The Tier I Annuity Component § 228.14 Family maximum. (a) Family maximum defined. Under... person's earnings record is limited. This limited amount is called the family maximum. The family maximum...

Estimation of maximum transdermal flux of nonionized xenobiotics from basic physicochemical determinants

PubMed Central

Milewski, Mikolaj; Stinchcomb, Audra L.

2012-01-01

An ability to estimate the maximum flux of a xenobiotic across skin is desirable both from the perspective of drug delivery and toxicology. While there is an abundance of mathematical models describing the estimation of drug permeability coefficients, there are relatively few that focus on the maximum flux. This article reports and evaluates a simple and easy-to-use predictive model for the estimation of maximum transdermal flux of xenobiotics based on three common molecular descriptors: logarithm of octanol-water partition coefficient, molecular weight and melting point. The use of all three can be justified on the theoretical basis of their influence on the solute aqueous solubility and the partitioning into the stratum corneum lipid domain. The model explains 81% of the variability in the permeation dataset comprised of 208 entries and can be used to obtain a quick estimate of maximum transdermal flux when experimental data is not readily available. PMID:22702370

40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes how to determine the maximum engine power, displacement, and power density of an engine for the...

40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes how to determine the maximum engine power, displacement, and power density of an engine for the...

Energy and maximum norm estimates for nonlinear conservation laws

NASA Technical Reports Server (NTRS)

Olsson, Pelle; Oliger, Joseph

1994-01-01

We have devised a technique that makes it possible to obtain energy estimates for initial-boundary value problems for nonlinear conservation laws. The two major tools to achieve the energy estimates are a certain splitting of the flux vector derivative f(u)(sub x), and a structural hypothesis, referred to as a cone condition, on the flux vector f(u). These hypotheses are fulfilled for many equations that occur in practice, such as the Euler equations of gas dynamics. It should be noted that the energy estimates are obtained without any assumptions on the gradient of the solution u. The results extend to weak solutions that are obtained as point wise limits of vanishing viscosity solutions. As a byproduct we obtain explicit expressions for the entropy function and the entropy flux of symmetrizable systems of conservation laws. Under certain circumstances the proposed technique can be applied repeatedly so as to yield estimates in the maximum norm.

Control of maximum metabolic rate in humans: dependence on performance phenotypes.

PubMed

Hochachka, Peter W; Burelle, Yan

2004-01-01

Borrowing from metabolic control analysis the concept of control coefficients or ci values, defined as fractional change in MMR/fractional change in the capacity of any given step in ATP turnover, we used four performance phenotypes to compare mechanisms of control of aerobic maximum metabolic rate (MMR): (i) untrained sedentary (US) subjects, as a reference group against which to compare (ii) power trained (PT), (iii) endurance trained (ET), and (iv) high altitude adapted native (HA) subject groups. Sprinters represented the PT group; long distance runners illustrated the ET group; and Andean natives represented the HA group. Numerous recent studies have identified contributors to control on both the adenosine triphosphate (ATP) supply side and the ATP demand side of ATP turnover. From the best available evidence it appears that at MMR all five of the major steps in energy delivery (namely, ventilation, pulmonary diffusion, cardiac output, tissue capillary--mitochondrial O2 transfer, and aerobic cell metabolism per se) approach an upper functional ceiling, with control strength being distributed amongst the various O2 flux steps. On the energy demand side, the situation is somewhat simplified since at MMR approximately 90% of O2-based ATP synthesis is used for actomyosin (AM) and Ca2+ ATPases; at MMR these two ATP demand rates also appear to be near an upper functional ceiling. In consequence, at MMR the control contributions or ci values are distributed amongst all seven major steps in ATP supply and ATP demand pathways right to the point of fatigue. Relative to US (the reference group), in PT subjects at MMR control strength shifts towards O2 delivery steps (ventilation, pulmonary diffusion, and cardiac output); here physiological regulation clearly dominates MMR control. In contrast in ET and HA subjects at MMR control shifts towards the energy demand steps (AM and Ca2+ ATPases), and more control strength is focussed on tissue level ATP supply and ATP demand

Maximum a posteriori classification of multifrequency, multilook, synthetic aperture radar intensity data

NASA Technical Reports Server (NTRS)

Rignot, E.; Chellappa, R.

1993-01-01

We present a maximum a posteriori (MAP) classifier for classifying multifrequency, multilook, single polarization SAR intensity data into regions or ensembles of pixels of homogeneous and similar radar backscatter characteristics. A model for the prior joint distribution of the multifrequency SAR intensity data is combined with a Markov random field for representing the interactions between region labels to obtain an expression for the posterior distribution of the region labels given the multifrequency SAR observations. The maximization of the posterior distribution yields Bayes's optimum region labeling or classification of the SAR data or its MAP estimate. The performance of the MAP classifier is evaluated by using computer-simulated multilook SAR intensity data as a function of the parameters in the classification process. Multilook SAR intensity data are shown to yield higher classification accuracies than one-look SAR complex amplitude data. The MAP classifier is extended to the case in which the radar backscatter from the remotely sensed surface varies within the SAR image because of incidence angle effects. The results obtained illustrate the practicality of the method for combining SAR intensity observations acquired at two different frequencies and for improving classification accuracy of SAR data.

Universality of maximum-work efficiency of a cyclic heat engine based on a finite system of ultracold atoms.

PubMed

Ye, Zhuolin; Hu, Yingying; He, Jizhou; Wang, Jianhui

2017-07-24

We study the performance of a cyclic heat engine which uses a small system with a finite number of ultracold atoms as its working substance and works between two heat reservoirs at constant temperatures T h and T c (maximum-work efficiency η mw at small relative temperature difference can be expanded in terms of the Carnot value [Formula: see text], [Formula: see text], where a 0 is a function depending on the particle number N and becomes vanishing in the symmetric case. Moreover, we prove using the relationship between the temperatures of the working substance and heat reservoirs that the maximum-work efficiency, when accurate to the first order of η C , reads [Formula: see text](ΔT 2 ). Within the framework of linear irreversible thermodynamics, the maximum-power efficiency is obtained as [Formula: see text](ΔT 2 ) through appropriate identification of thermodynamic fluxes and forces, thereby showing that this kind of cyclic heat engines satisfy the tight-coupling condition.

Maximum Acceleration Recording Circuit

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

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

Obtaining high g-values with low degree expansion of the phasefunction

NASA Astrophysics Data System (ADS)

Rinzema, Kees; ten Bosch, Jaap J.; Ferwerda, Hedzer A.; Hoenders, Bernhard J.

1994-02-01

Analytic theory of anisotropic random flight requires the expansion of phase-functions in spherical harmonics. The number of terms should be limited while a g value should be obtained that is as high as possible. We describe how such a phase function can be constructed for a given number N of spherical components of the phasefunction, while obtaining a maximum value of the asymmetry parameter g.

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

PubMed

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

2014-12-02

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

Performance of J33 turbojet engine with shaft-power extraction III : turbine performance

NASA Technical Reports Server (NTRS)

Huppert, M C; Nettles, J C

1949-01-01

The performance of the turbine component of a J33 turbojet engine was determined over a range of turbine speeds from 8000 to 11,500 rpm.Turbine-inlet temperature was varied from the minimum required to drive the compressor to a maximum of approximately 2000 degrees R at each of several intermediate turbine speeds. Data are presented that show the horsepower developed by the turbine per pound of gas flow. The relation between turbine-inlet stagnation pressure, turbine-outlet stagnation pressure, and turbine-outlet static pressure was established. The turbine-weight-flow parameter varied from 39.2 to 43.6. The maximum turbine efficiency measured was 0.86 at a pressure ratio of 3.5 and a ratio of blade speed to theoretical nozzle velocity of 0.39. A generalized performance map of the turbine-horsepower parameter plotted against the turbine-speed parameter indicated that the best turbine efficiency is obtained when the turbine power is 10 percent greater than the compressor horsepower. The variation of efficiency with the ratio of blade speed to nozzle velocity indicated that the turbine operates at a speed above that for maximum efficiency when the engine is operated normally with the 19-inch-diameter jet nozzle.

Infrared image segmentation method based on spatial coherence histogram and maximum entropy

NASA Astrophysics Data System (ADS)

Liu, Songtao; Shen, Tongsheng; Dai, Yao

2014-11-01

In order to segment the target well and suppress background noises effectively, an infrared image segmentation method based on spatial coherence histogram and maximum entropy is proposed. First, spatial coherence histogram is presented by weighting the importance of the different position of these pixels with the same gray-level, which is obtained by computing their local density. Then, after enhancing the image by spatial coherence histogram, 1D maximum entropy method is used to segment the image. The novel method can not only get better segmentation results, but also have a faster computation time than traditional 2D histogram-based segmentation methods.

Efficiency at maximum power output of linear irreversible Carnot-like heat engines

NASA Astrophysics Data System (ADS)

Wang, Yang; Tu, Z. C.

2012-01-01

The efficiency at maximum power output of linear irreversible Carnot-like heat engines is investigated based on the assumption that the rate of irreversible entropy production of the working substance in each “isothermal” process is a quadratic form of the heat exchange rate between the working substance and the reservoir. It is found that the maximum power output corresponds to minimizing the irreversible entropy production in two isothermal processes of the Carnot-like cycle, and that the efficiency at maximum power output has the form ηmP=ηC/(2-γηC), where ηC is the Carnot efficiency, while γ depends on the heat transfer coefficients between the working substance and two reservoirs. The value of ηmP is bounded between η-≡ηC/2 and η+≡ηC/(2-ηC). These results are consistent with those obtained by Chen and Yan [J. Chem. Phys.JCPSA60021-960610.1063/1.455832 90, 3740 (1989)] based on the endoreversible assumption, those obtained by Esposito [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.105.150603 105, 150603 (2010)] based on the low-dissipation assumption, and those obtained by Schmiedl and Seifert [Europhys. Lett.EULEEJ0295-507510.1209/0295-5075/81/20003 81, 20003 (2008)] for stochastic heat engines which in fact also satisfy the low-dissipation assumption. Additionally, we find that the endoreversible assumption happens to hold for Carnot-like heat engines operating at the maximum power output based on our fundamental assumption, and that the Carnot-like heat engines that we focused on do not strictly satisfy the low-dissipation assumption, which implies that the low-dissipation assumption or our fundamental assumption is a sufficient but non-necessary condition for the validity of ηmP=ηC/(2-γηC) as well as the existence of two bounds, η-≡ηC/2 and η+≡ηC/(2-ηC).

Maximum principle for a stochastic delayed system involving terminal state constraints.

PubMed

Wen, Jiaqiang; Shi, Yufeng

2017-01-01

We investigate a stochastic optimal control problem where the controlled system is depicted as a stochastic differential delayed equation; however, at the terminal time, the state is constrained in a convex set. We firstly introduce an equivalent backward delayed system depicted as a time-delayed backward stochastic differential equation. Then a stochastic maximum principle is obtained by virtue of Ekeland's variational principle. Finally, applications to a state constrained stochastic delayed linear-quadratic control model and a production-consumption choice problem are studied to illustrate the main obtained result.

An EM Algorithm for Maximum Likelihood Estimation of Process Factor Analysis Models

ERIC Educational Resources Information Center

Lee, Taehun

2010-01-01

In this dissertation, an Expectation-Maximization (EM) algorithm is developed and implemented to obtain maximum likelihood estimates of the parameters and the associated standard error estimates characterizing temporal flows for the latent variable time series following stationary vector ARMA processes, as well as the parameters defining the…

Parametric performance of circumferentially grooved heat pipes with homogeneous and graded-porosity slab wicks at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Groll, M.; Pittman, R. B.; Eninger, J. E.

1975-01-01

A recently developed, potentially high-performance nonarterial wick has been extensively tested. This slab wick has an axially varying porosity which can be tailored to match the local stress imposed on the wick. The purpose of the tests was to establish the usefulness of the graded-porosity slab wick at cryogenic temperatures between 110 K and 260 K, with methane and ethane as working fluids. For comparison, a homogeneous (i.e., uniform porosity) slab wick was also tested. The tests included: (1) maximum heat pipe performance as a function of fluid inventory, (2) maximum performance as a function of operating temperature, (3) maximum performance as a function of evaporator elevation, and (4) influence of slab wick orientation on performance. The experimental data was compared with theoretical predictions obtained with the computer program GRADE.

Comparative Flight and Full-Scale Wind-Tunnel Measurements of the Maximum Lift of an Airplane

NASA Technical Reports Server (NTRS)

Silverstein, Abe; Katzoff, S; Hootman, James A

1938-01-01

Determinations of the power-off maximum lift of a Fairchild 22 airplane were made in the NACA full-scale wind tunnel and in flight. The results from the two types of test were in satisfactory agreement. It was found that, when the airplane was rotated positively in pitch through the angle of stall at rates of the order of 0.1 degree per second, the maximum lift coefficient was considerably higher than that obtained in the standard tests, in which the forces are measured with the angles of attack fixed. Scale effect on the maximum lift coefficient was also investigated.

Hybrid genetic algorithm in the Hopfield network for maximum 2-satisfiability problem

NASA Astrophysics Data System (ADS)

Kasihmuddin, Mohd Shareduwan Mohd; Sathasivam, Saratha; Mansor, Mohd. Asyraf

2017-08-01

Heuristic method was designed for finding optimal solution more quickly compared to classical methods which are too complex to comprehend. In this study, a hybrid approach that utilizes Hopfield network and genetic algorithm in doing maximum 2-Satisfiability problem (MAX-2SAT) was proposed. Hopfield neural network was used to minimize logical inconsistency in interpretations of logic clauses or program. Genetic algorithm (GA) has pioneered the implementation of methods that exploit the idea of combination and reproduce a better solution. The simulation incorporated with and without genetic algorithm will be examined by using Microsoft Visual 2013 C++ Express software. The performance of both searching techniques in doing MAX-2SAT was evaluate based on global minima ratio, ratio of satisfied clause and computation time. The result obtained form the computer simulation demonstrates the effectiveness and acceleration features of genetic algorithm in doing MAX-2SAT in Hopfield network.

Chapman Enskog-maximum entropy method on time-dependent neutron transport equation

NASA Astrophysics Data System (ADS)

Abdou, M. A.

2006-09-01

The time-dependent neutron transport equation in semi and infinite medium with linear anisotropic and Rayleigh scattering is proposed. The problem is solved by means of the flux-limited, Chapman Enskog-maximum entropy for obtaining the solution of the time-dependent neutron transport. The solution gives the neutron distribution density function which is used to compute numerically the radiant energy density E(x,t), net flux F(x,t) and reflectivity Rf. The behaviour of the approximate flux-limited maximum entropy neutron density function are compared with those found by other theories. Numerical calculations for the radiant energy, net flux and reflectivity of the proposed medium are calculated at different time and space.

Maximum occlusal force and physical performance in the oldest old: the Tokyo oldest old survey on total health.

PubMed

Iinuma, Toshimitsu; Arai, Yasumichi; Fukumoto, Motoko; Takayama, Michiyo; Abe, Yukiko; Asakura, Keiko; Nishiwaki, Yuji; Takebayashi, Toru; Iwase, Takashi; Komiyama, Kazuo; Gionhaku, Nobuhito; Hirose, Nobuyoshi

2012-01-01

To elucidate the independent relationship between masticatory and physical performance in community-living oldest old people (mean age ± standard deviation 87.8 ± 2.2, range 85-102). Cross-sectional analysis. University research center or home-based examination. Four hundred eighty-nine community-living individuals (219 men, 270 women) aged 85 and older. Maximum occlusal force (MOF) was measured using an occlusal force measuring device. Sociodemographic and functional factors, oral health, comorbidities, blood chemistry, lower extremity performance, and handgrip strength were assessed. Blood chemistry analyses included serum albumin, C-reactive protein, interleukin (IL)-6, and total and free testosterone. MOF was significantly associated with age, body mass index, and cognitive impairment in men but not in women. Comorbidities and blood chemistry were not associated with MOF except for a significant association with IL-6 concentration in women. In a multivariate model adjusted for various confounders, lower MOF was associated with greater risk for poor performance on the timed up and go (TUG) test in men and women (men: odds ratio (OR)=2.34, 95% confidence interval (CI)=1.02-5.38; women: OR=2.44, 95% CI=1.12-5.33). MOF was similarly associated with performance in chair standing, one-leg standing, and handgrip strength only in men. These associations remained after adjustment for number of natural teeth. MOF was strongly and independently associated with all measures of physical performance in men and with the TUG test in women after adjustment for various confounders, suggesting that age-related declines in masticatory and skeletal muscle functions share common mechanistic pathways in older age, particularly in men. © 2011, Copyright the Authors Journal compilation © 2011, The American Geriatrics Society.

In vitro performance of ceramic coatings obtained by high velocity oxy-fuel spray.

PubMed

Melero, H; Garcia-Giralt, N; Fernández, J; Díez-Pérez, A; Guilemany, J M

2014-01-01

Hydroxyapatite coatings obtained by plasma-spraying have been used for many years to improve biological performance of bone implants, but several studies have drawn attention to the problems arising from high temperatures and the lack of mechanical properties. In this study, plasma-spraying is substituted by high velocity oxy-fuel (HVOF) spray, with lower temperatures reached, and TiO2 is added in low amounts to hydroxyapatite in order to improve the mechanical properties. Four conditions have been tested to evaluate which are those with better biological properties. Viability and proliferation tests, as well as differentiation assays and morphology observation, are performed with human osteoblast cultures onto the studied coatings. The hydroxyapatite-TiO2 coatings maintain good cell viability and proliferation, especially the cases with higher amorphous phase amount and specific surface, and promote excellent differentiation, with a higher ALP amount for these cases than for polystyrene controls. Observation by SEM corroborates this excellent behaviour. In conclusion, these coatings are a good alternative to those used industrially, and an interesting issue would be improving biological behaviour of the worst cases, which in turn show the better mechanical properties.

Maximum Oxygen Uptake Determination in Insulin-Dependent Diabetes Mellitus.

ERIC Educational Resources Information Center

Fremion, Amy S.; And Others

1987-01-01

A study of 10 children with insulin-dependent diabetes mellitus performing a maximum-effort cycling test indicated blood glucose levels did not change appreciably during test, while maximal oxygen uptake was substandard for their age groups. Findings suggest patients in fair to poor metabolic control can tolerate stress testing without…

Impact of Clinical History on Maximum PI-RADS Version 2 Score: A Six-Reader 120-Case Sham History Retrospective Evaluation.

PubMed

Shankar, Prasad R; Kaza, Ravi K; Al-Hawary, Mahmoud M; Masch, William R; Curci, Nicole E; Mendiratta-Lala, Mishal; Sakala, Michelle D; Johnson, Timothy D; Davenport, Matthew S

2018-04-17

Purpose To assess the impact of clinical history on the maximum Prostate Imaging Recording and Data System (PI-RADS) version 2 (v2) score assigned to multiparametric magnetic resonance (MR) imaging of the prostate. Materials and Methods This retrospective cohort study included 120 consecutively selected multiparametric prostate MR imaging studies performed between November 1, 2016, and December 31, 2016. Sham clinical data in four domains (digital rectal examination, prostate-specific antigen level, plan for biopsy, prior prostate cancer history) were randomly assigned to each case by using a balanced orthogonal design. Six fellowship-trained abdominal radiologists independently reviewed the sham data, actual patient age, and each examination while they were blinded to interreader scoring, true clinical data, and histologic findings. Readers were told the constant sham histories were true, believed the study to be primarily investigating interrater agreement, and were asked to assign a maximum PI-RADS v2 score to each case. Linear regression was performed to assess the association between clinical variables and maximum PI-RADS v2 score designation. Intraclass correlation coefficients (ICCs) were obtained to compare interreader scoring. Results Clinical information had no significant effect on maximum PI-RADS v2 scoring for any of the six readers (P = .09-.99, 42 reader-variable pairs). Distributions of maximum PI-RADS v2 scores in the research context were similar to the distribution of the scores assigned clinically and had fair-to-excellent pairwise interrater agreement (ICC range: 0.53-0.76). Overall interrater agreement was good (ICC: 0.64; 95% confidence interval: 0.57, 0.71). Conclusion Clinical history does not appear to be a substantial bias in maximum PI-RADS v2 score assignment. This is potentially important for clinical nomograms that plan to incorporate PI-RADS v2 score and clinical data into their algorithms (ie, PI-RADS v2 scoring is not confounded by

Sub-200 ps CRT in monolithic scintillator PET detectors using digital SiPM arrays and maximum likelihood interaction time estimation.

PubMed

van Dam, Herman T; Borghi, Giacomo; Seifert, Stefan; Schaart, Dennis R

2013-05-21

Digital silicon photomultiplier (dSiPM) arrays have favorable characteristics for application in monolithic scintillator detectors for time-of-flight positron emission tomography (PET). To fully exploit these benefits, a maximum likelihood interaction time estimation (MLITE) method was developed to derive the time of interaction from the multiple time stamps obtained per scintillation event. MLITE was compared to several deterministic methods. Timing measurements were performed with monolithic scintillator detectors based on novel dSiPM arrays and LSO:Ce,0.2%Ca crystals of 16 × 16 × 10 mm(3), 16 × 16 × 20 mm(3), 24 × 24 × 10 mm(3), and 24 × 24 × 20 mm(3). The best coincidence resolving times (CRTs) for pairs of identical detectors were obtained with MLITE and measured 157 ps, 185 ps, 161 ps, and 184 ps full-width-at-half-maximum (FWHM), respectively. For comparison, a small reference detector, consisting of a 3 × 3 × 5 mm(3) LSO:Ce,0.2%Ca crystal coupled to a single pixel of a dSiPM array, was measured to have a CRT as low as 120 ps FWHM. The results of this work indicate that the influence of the optical transport of the scintillation photons on the timing performance of monolithic scintillator detectors can at least partially be corrected for by utilizing the information contained in the spatio-temporal distribution of the collection of time stamps registered per scintillation event.

Sub-200 ps CRT in monolithic scintillator PET detectors using digital SiPM arrays and maximum likelihood interaction time estimation

NASA Astrophysics Data System (ADS)

van Dam, Herman T.; Borghi, Giacomo; Seifert, Stefan; Schaart, Dennis R.

2013-05-01

Digital silicon photomultiplier (dSiPM) arrays have favorable characteristics for application in monolithic scintillator detectors for time-of-flight positron emission tomography (PET). To fully exploit these benefits, a maximum likelihood interaction time estimation (MLITE) method was developed to derive the time of interaction from the multiple time stamps obtained per scintillation event. MLITE was compared to several deterministic methods. Timing measurements were performed with monolithic scintillator detectors based on novel dSiPM arrays and LSO:Ce,0.2%Ca crystals of 16 × 16 × 10 mm3, 16 × 16 × 20 mm3, 24 × 24 × 10 mm3, and 24 × 24 × 20 mm3. The best coincidence resolving times (CRTs) for pairs of identical detectors were obtained with MLITE and measured 157 ps, 185 ps, 161 ps, and 184 ps full-width-at-half-maximum (FWHM), respectively. For comparison, a small reference detector, consisting of a 3 × 3 × 5 mm3 LSO:Ce,0.2%Ca crystal coupled to a single pixel of a dSiPM array, was measured to have a CRT as low as 120 ps FWHM. The results of this work indicate that the influence of the optical transport of the scintillation photons on the timing performance of monolithic scintillator detectors can at least partially be corrected for by utilizing the information contained in the spatio-temporal distribution of the collection of time stamps registered per scintillation event.

Maximum relative speeds of living organisms: Why do bacteria perform as fast as ostriches?

NASA Astrophysics Data System (ADS)

Meyer-Vernet, Nicole; Rospars, Jean-Pierre

2016-12-01

Self-locomotion is central to animal behaviour and survival. It is generally analysed by focusing on preferred speeds and gaits under particular biological and physical constraints. In the present paper we focus instead on the maximum speed and we study its order-of-magnitude scaling with body size, from bacteria to the largest terrestrial and aquatic organisms. Using data for about 460 species of various taxonomic groups, we find a maximum relative speed of the order of magnitude of ten body lengths per second over a 1020-fold mass range of running and swimming animals. This result implies a locomotor time scale of the order of one tenth of second, virtually independent on body size, anatomy and locomotion style, whose ubiquity requires an explanation building on basic properties of motile organisms. From first-principle estimates, we relate this generic time scale to other basic biological properties, using in particular the recent generalisation of the muscle specific tension to molecular motors. Finally, we go a step further by relating this time scale to still more basic quantities, as environmental conditions at Earth in addition to fundamental physical and chemical constants.

Coalescent-based species tree inference from gene tree topologies under incomplete lineage sorting by maximum likelihood.

PubMed

Wu, Yufeng

2012-03-01

Incomplete lineage sorting can cause incongruence between the phylogenetic history of genes (the gene tree) and that of the species (the species tree), which can complicate the inference of phylogenies. In this article, I present a new coalescent-based algorithm for species tree inference with maximum likelihood. I first describe an improved method for computing the probability of a gene tree topology given a species tree, which is much faster than an existing algorithm by Degnan and Salter (2005). Based on this method, I develop a practical algorithm that takes a set of gene tree topologies and infers species trees with maximum likelihood. This algorithm searches for the best species tree by starting from initial species trees and performing heuristic search to obtain better trees with higher likelihood. This algorithm, called STELLS (which stands for Species Tree InfErence with Likelihood for Lineage Sorting), has been implemented in a program that is downloadable from the author's web page. The simulation results show that the STELLS algorithm is more accurate than an existing maximum likelihood method for many datasets, especially when there is noise in gene trees. I also show that the STELLS algorithm is efficient and can be applied to real biological datasets. © 2011 The Author. Evolution© 2011 The Society for the Study of Evolution.

Repeatability and reproducibility of measurements of the suburethral tape location obtained in pelvic floor ultrasound performed with a transvaginal probe

PubMed Central

Dresler, Maria Magdalena; Kociszewski, Jacek; Pędraszewski, Piotr; Trzeciak, Agnieszka; Surkont, Grzegorz

2017-01-01

Introduction Implants used to treat patients with urogynecological conditions are well visible in US examination. The position of the suburethral tape (sling) is determined in relation to the urethra or the pubic symphysis. Aim of the study The study was aimed at assessing the accuracy of measurements determining suburethral tape location obtained in pelvic US examination performed with a transvaginal probe. Material and methods The analysis covered the results of sonographic measurements obtained according to a standardized technique in women referred for urogynecological diagnostics. Data from a total of 68 patients were used to analyse the repeatability and reproducibility of results obtained on the same day. Results The intraclass correlation coefficient for the repeatability and reproducibility of the sonographic measurements of suburethral tape location obtained with a transvaginal probe ranged from 0.6665 to 0.9911. The analysis of the measurements confirmed their consistency to be excellent or good. Conclusions Excellent and good repeatability and reproducibility of the measurements of the suburethral tape location obtained in a pelvic ultrasound performed with a transvaginal probe confirm the test’s validity and usefulness for clinical and academic purposes. PMID:28856017

34 CFR 386.42 - What must a scholar do to obtain a deferral or exception to performance or repayment under a...

Code of Federal Regulations, 2014 CFR

2014-07-01

... to performance or repayment under a scholarship agreement? 386.42 Section 386.42 Education... performance or repayment under a scholarship agreement? To obtain a deferral or exception to performance or repayment under a scholarship agreement, a scholar shall provide the following: (a) Written application. A...

34 CFR 386.42 - What must a scholar do to obtain a deferral or exception to performance or repayment under a...

Code of Federal Regulations, 2011 CFR

2011-07-01

... to performance or repayment under a scholarship agreement? 386.42 Section 386.42 Education... performance or repayment under a scholarship agreement? To obtain a deferral or exception to performance or repayment under a scholarship agreement, a scholar shall provide the following: (a) Written application. A...

Guidelines for developing spacecraft maximum allowable concentrations for Space Station contaminants

NASA Technical Reports Server (NTRS)

1992-01-01

The National Aeronautics and Space Administration (NASA) is preparing to launch a manned space station by the year 1996. Because of concerns about the health, safety, and functioning abilities of the crews, NASA has requested that the National Research Council (NRC) through the Board on Environmental Studies and Toxicology (BEST) provide advice on toxicological matters for the space-station program. The Subcommittee on Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants was established by the Committee on Toxicology (COT) to address NASA's concerns. Spacecraft maximum allowable concentrations (SMAC's) are defined as the maximum concentrations of airborne substances (such as gas, vapor, or aerosol) that will not cause adverse health effects, significant discomfort, or degradation in crew performance.

34 CFR 386.42 - What must a scholar do to obtain a deferral or exception to performance or repayment under a...

Code of Federal Regulations, 2010 CFR

2010-07-01

... exception to performance or repayment under a scholarship agreement? 386.42 Section 386.42 Education... performance or repayment under a scholarship agreement? To obtain a deferral or exception to performance or repayment under a scholarship agreement, a scholar shall provide the following: (a) Written application. A...

34 CFR 386.42 - What must a scholar do to obtain a deferral or exception to performance or repayment under a...

Code of Federal Regulations, 2012 CFR

2012-07-01

... exception to performance or repayment under a scholarship agreement? 386.42 Section 386.42 Education... performance or repayment under a scholarship agreement? To obtain a deferral or exception to performance or repayment under a scholarship agreement, a scholar shall provide the following: (a) Written application. A...

34 CFR 386.42 - What must a scholar do to obtain a deferral or exception to performance or repayment under a...

Code of Federal Regulations, 2013 CFR

2013-07-01

... exception to performance or repayment under a scholarship agreement? 386.42 Section 386.42 Education... performance or repayment under a scholarship agreement? To obtain a deferral or exception to performance or repayment under a scholarship agreement, a scholar shall provide the following: (a) Written application. A...

Understanding the Role of Reservoir Size on Probable Maximum Precipitation

NASA Astrophysics Data System (ADS)

Woldemichael, A. T.; Hossain, F.

2011-12-01

This study addresses the question 'Does surface area of an artificial reservoir matter in the estimation of probable maximum precipitation (PMP) for an impounded basin?' The motivation of the study was based on the notion that the stationarity assumption that is implicit in the PMP for dam design can be undermined in the post-dam era due to an enhancement of extreme precipitation patterns by an artificial reservoir. In addition, the study lays the foundation for use of regional atmospheric models as one way to perform life cycle assessment for planned or existing dams to formulate best management practices. The American River Watershed (ARW) with the Folsom dam at the confluence of the American River was selected as the study region and the Dec-Jan 1996-97 storm event was selected for the study period. The numerical atmospheric model used for the study was the Regional Atmospheric Modeling System (RAMS). First, the numerical modeling system, RAMS, was calibrated and validated with selected station and spatially interpolated precipitation data. Best combinations of parameterization schemes in RAMS were accordingly selected. Second, to mimic the standard method of PMP estimation by moisture maximization technique, relative humidity terms in the model were raised to 100% from ground up to the 500mb level. The obtained model-based maximum 72-hr precipitation values were named extreme precipitation (EP) as a distinction from the PMPs obtained by the standard methods. Third, six hypothetical reservoir size scenarios ranging from no-dam (all-dry) to the reservoir submerging half of basin were established to test the influence of reservoir size variation on EP. For the case of the ARW, our study clearly demonstrated that the assumption of stationarity that is implicit the traditional estimation of PMP can be rendered invalid to a large part due to the very presence of the artificial reservoir. Cloud tracking procedures performed on the basin also give indication of the

F/A-18 Performance Benefits Measured During the Autonomous Formation Flight Project

NASA Technical Reports Server (NTRS)

Vachon, M. Jake; Ray, Ronald J.; Walsh, Kevin R.; Ennix, Kimberly

2003-01-01

The Autonomous Formation Flight (AFF) project at the NASA Dryden Flight Research Center (Edwards, California) investigated performance benefits resulting from formation flight, such as reduced aerodynamic drag and fuel consumption. To obtain data on performance benefits, a trailing F/A-18 airplane flew within the wing tip-shed vortex of a leading F/A-18 airplane. The pilot of the trail airplane used advanced station-keeping technology to aid in positioning the trail airplane at precise locations behind the lead airplane. The specially instrumented trail airplane was able to obtain accurate fuel flow measurements and to calculate engine thrust and vehicle drag. A maneuver technique developed for this test provided a direct comparison of performance values while flying in and out of the vortex. Based on performance within the vortex as a function of changes in vertical, lateral, and longitudinal positioning, these tests explored design-drivers for autonomous stationkeeping control systems. Observations showed significant performance improvements over a large range of trail positions tested. Calculations revealed maximum drag reductions of over 20 percent, and demonstrated maximum reductions in fuel flow of just over 18 percent.

Specific considerations for obtaining appropriate La1-xSrxGa1-yMgyO3-δ thin films using pulsed-laser deposition and its influence on the performance of solid-oxide fuel cells

NASA Astrophysics Data System (ADS)

Hwang, Jaeyeon; Lee, Heon; Lee, Jong-Ho; Yoon, Kyung Joong; Kim, Hyoungchul; Hong, Jongsup; Son, Ji-Won

2015-01-01

To obtain La1-xSrxGa1-yMgyO3-δ (LSGM) thin films with the appropriate properties, pulsed-laser deposition (PLD) is employed, and specific considerations regarding control of the deposition parameters is investigated. It is demonstrated that with a target of stoichiometric composition, appropriate LSGM thin films cannot be produced because of the deviation of the composition from the target to the thin film. Only after adjusting the target composition an LSGM thin film with an appropriate composition and phase can be obtained. The optimized LSGM thin film possesses an electrical conductivity close to that of the bulk LSGM. In contrast, non-optimized thin films do not yield any measurable electrical conductivity. The impact of the optimization of the LSGM thin-film electrolyte on the cell performance is quite significant, in that a solid-oxide fuel cell (SOFC) with an optimized LSGM thin-film electrolyte produces a maximum power density of 1.1 W cm-2 at 600 °C, whereas an SOFC with a non-optimal LSGM thin-film electrolyte is not operable.

An extended heterogeneous car-following model accounting for anticipation driving behavior and mixed maximum speeds

NASA Astrophysics Data System (ADS)

Sun, Fengxin; Wang, Jufeng; Cheng, Rongjun; Ge, Hongxia

2018-02-01

The optimal driving speeds of the different vehicles may be different for the same headway. In the optimal velocity function of the optimal velocity (OV) model, the maximum speed vmax is an important parameter determining the optimal driving speed. A vehicle with higher maximum speed is more willing to drive faster than that with lower maximum speed in similar situation. By incorporating the anticipation driving behavior of relative velocity and mixed maximum speeds of different percentages into optimal velocity function, an extended heterogeneous car-following model is presented in this paper. The analytical linear stable condition for this extended heterogeneous traffic model is obtained by using linear stability theory. Numerical simulations are carried out to explore the complex phenomenon resulted from the cooperation between anticipation driving behavior and heterogeneous maximum speeds in the optimal velocity function. The analytical and numerical results all demonstrate that strengthening driver's anticipation effect can improve the stability of heterogeneous traffic flow, and increasing the lowest value in the mixed maximum speeds will result in more instability, but increasing the value or proportion of the part already having higher maximum speed will cause different stabilities at high or low traffic densities.

Extracting maximum power from active colloidal heat engines

NASA Astrophysics Data System (ADS)

Martin, D.; Nardini, C.; Cates, M. E.; Fodor, É.

2018-03-01

Colloidal heat engines extract power out of a fluctuating bath by manipulating a confined tracer. Considering a self-propelled tracer surrounded by a bath of passive colloids, we optimize the engine performances based on the maximum available power. Our approach relies on an adiabatic mean-field treatment of the bath particles which reduces the many-body description into an effective tracer dynamics. It leads us to reveal that, when operated at constant activity, an engine can only produce less maximum power than its passive counterpart. In contrast, the output power of an isothermal engine, operating with cyclic variations of the self-propulsion without any passive equivalent, exhibits an optimum in terms of confinement and activity. Direct numerical simulations of the microscopic dynamics support the validity of these results even beyond the mean-field regime, with potential relevance to the design of experimental engines.

Developing the fuzzy c-means clustering algorithm based on maximum entropy for multitarget tracking in a cluttered environment

NASA Astrophysics Data System (ADS)

Chen, Xiao; Li, Yaan; Yu, Jing; Li, Yuxing

2018-01-01

For fast and more effective implementation of tracking multiple targets in a cluttered environment, we propose a multiple targets tracking (MTT) algorithm called maximum entropy fuzzy c-means clustering joint probabilistic data association that combines fuzzy c-means clustering and the joint probabilistic data association (PDA) algorithm. The algorithm uses the membership value to express the probability of the target originating from measurement. The membership value is obtained through fuzzy c-means clustering objective function optimized by the maximum entropy principle. When considering the effect of the public measurement, we use a correction factor to adjust the association probability matrix to estimate the state of the target. As this algorithm avoids confirmation matrix splitting, it can solve the high computational load problem of the joint PDA algorithm. The results of simulations and analysis conducted for tracking neighbor parallel targets and cross targets in a different density cluttered environment show that the proposed algorithm can realize MTT quickly and efficiently in a cluttered environment. Further, the performance of the proposed algorithm remains constant with increasing process noise variance. The proposed algorithm has the advantages of efficiency and low computational load, which can ensure optimum performance when tracking multiple targets in a dense cluttered environment.

High dose rates obtained outside ISS in June 2015 during SEP event

NASA Astrophysics Data System (ADS)

Dachev, T. P.; Tomov, B. T.; Matviichuk, Yu. N.; Dimitrov, Pl. G.; Bankov, N. G.

2016-06-01

The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform outside the Russian "Zvezda" module of the International Space Station (ISS) in the period 24 October 2014-11 January 2016. It is the Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2015a). Took place in November 2014, this was the first attempt to monitor a small solar energetic particle (SEP) event outside ISS using the Liulin-type DES (Dachev et al., 2015d). In this study, we describe the dosimetric characteristics of the largest SEP event, observed on 22 June 2015 with the R3DR2 instrument outside ISS. The main finding of this study is that SEP protons with a minimum energy of approximately 7 MeV at the surface of the R3DR2 detector produced high dose rates, reaching >5000 μGy h-1, while the inner radiation belt maximum dose was at the level of 2200 μGy h-1. If a virtual external vehicle activity (EVA) was performed in the same period of the SEP maximum on 22 June 2015, the doses obtained in the skin of cosmonauts/astronauts can reach 2.84 mGy after 6.5 h, which is similar to the average absorbed dose inside ISS for 15 days (Reitz et al., 2005). A comparison with other extreme events measured with Liulin-type instruments shows that SEPs similar to that observed on 22 June 2015 could be one of the most dangerous events for the cosmonauts/astronauts involved in EVA.

An improved maximum power point tracking method for a photovoltaic system

NASA Astrophysics Data System (ADS)

Ouoba, David; Fakkar, Abderrahim; El Kouari, Youssef; Dkhichi, Fayrouz; Oukarfi, Benyounes

2016-06-01

In this paper, an improved auto-scaling variable step-size Maximum Power Point Tracking (MPPT) method for photovoltaic (PV) system was proposed. To achieve simultaneously a fast dynamic response and stable steady-state power, a first improvement was made on the step-size scaling function of the duty cycle that controls the converter. An algorithm was secondly proposed to address wrong decision that may be made at an abrupt change of the irradiation. The proposed auto-scaling variable step-size approach was compared to some various other approaches from the literature such as: classical fixed step-size, variable step-size and a recent auto-scaling variable step-size maximum power point tracking approaches. The simulation results obtained by MATLAB/SIMULINK were given and discussed for validation.

Efficiency at Maximum Power Output of a Quantum-Mechanical Brayton Cycle

NASA Astrophysics Data System (ADS)

Yuan, Yuan; He, Ji-Zhou; Gao, Yong; Wang, Jian-Hui

2014-03-01

The performance in finite time of a quantum-mechanical Brayton engine cycle is discussed, without introduction of temperature. The engine model consists of two quantum isoenergetic and two quantum isobaric processes, and works with a single particle in a harmonic trap. Directly employing the finite-time thermodynamics, the efficiency at maximum power output is determined. Extending the harmonic trap to a power-law trap, we find that the efficiency at maximum power is independent of any parameter involved in the model, but depends on the confinement of the trapping potential.

Comparison of VO[subscript 2] Maximum Obtained from 20 m Shuttle Run and Cycle Ergometer in Children with and without Developmental Coordination Disorder

ERIC Educational Resources Information Center

Cairney, John; Hay, John; Veldhuizen, Scott; Faught, Brent

2010-01-01

Oxygen consumption at peak physical exertion (VO[subscript 2] maximum) is the most widely used indicator of cardiorespiratory fitness. The purpose of this study was to compare two protocols for its estimation, cycle ergometer testing and the 20 m shuttle run, among children with and without probable developmental coordination disorder (pDCD). The…

Mean common or mean maximum carotid intima-media thickness as primary outcome in lipid-modifying intervention studies.

PubMed

Dogan, Soner; Kastelein, Johannes Jacob Pieter; Grobbee, Diederick Egbertus; Bots, Michiel Leonardus

2011-01-01

Carotid intima-media thickness (CIMT) measurements are used as a disease outcome in randomized controlled trials that assess the effects of lipid-modifying treatment. It is unclear whether common CIMT or mean maximum CIMT should be used as the primary outcome. We directly compared both measurements using aspects that are of great importance in deciding which is most favorable for use in clinical trials. A literature search was performed (PUBMED, up to March 31, 2008). Fifteen trials with lipid-modifying treatment were identified that had information on both outcome measures. Common CIMT and mean maximum CIMT were compared on reproducibility, strength of relation with LDL and HDL cholesterol and congruency of their results (harm/neutral/beneficial) with data from event trials. Findings showed that the reported reproducibility was high for both measurements, although a direct comparison was not possible. The relationship between the achieved LDL-C and HDL-C levels with CIMT progression was modest and showed no difference in magnitude between CIMT measurements. CIMT progression rates differed across carotid segments with the highest progression rates observed in the bifurcation segment. Treatment effects differed across carotid segments without a clear preference pattern. Trials using mean maximum CIMT progression more often (12 out of 15 studies) paralleled the findings of event trials in contrast to the mean common CIMT (11 out of 15 studies), a difference not reaching statistical significance. Based on the literature, with equal results for reproducibility (assumed), lipid relationship and congruency with event findings, but with treatment effects that differ across carotid segments that can not be predicted, the mean maximum CIMT as the primary outcome may be preferred in trials on the impact of lipid-modifying interventions. One advantage is that information on mean common CIMT can generally be obtained easily in protocols assessing mean maximum CIMT, but not the

5 CFR 1600.22 - Maximum contributions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Maximum contributions. 1600.22 Section... ELECTIONS AND CONTRIBUTION ALLOCATIONS Program of Contributions § 1600.22 Maximum contributions. (a) Regular...) FERS percentage limit. The maximum employee contribution from basic pay for a FERS participant for 2005...

Maximum Likelihood Dynamic Factor Modeling for Arbitrary "N" and "T" Using SEM

ERIC Educational Resources Information Center

Voelkle, Manuel C.; Oud, Johan H. L.; von Oertzen, Timo; Lindenberger, Ulman

2012-01-01

This article has 3 objectives that build on each other. First, we demonstrate how to obtain maximum likelihood estimates for dynamic factor models (the direct autoregressive factor score model) with arbitrary "T" and "N" by means of structural equation modeling (SEM) and compare the approach to existing methods. Second, we go beyond standard time…

Statistical downscaling of CMIP5 outputs for projecting future maximum and minimum temperature over the Haihe River Bain, China

NASA Astrophysics Data System (ADS)

Yan, Tiezhu; Shen, Zhenyao; Heng, Lee; Dercon, Gerd

2016-04-01

Future climate change information is important to formulate adaptation and mitigation strategies for climate change. In this study, a statistical downscaling model (SDSM) was established using both NCEP reanalysis data and ground observations (daily maximum and minimum temperature) during the period 1971-2010, and then calibrated model was applied to generate the future maximum and minimum temperature projections using predictors from the two CMIP5 models (MPI-ESM-LR and CNRM-CM5) under two Representative Concentration Pathway (RCP2.6 and RCP8.5) during the period 2011-2100 for the Haihe River Basin, China. Compared to the baseline period, future change in annual and seasonal maximum and minimum temperature was computed after bias correction. The spatial distribution and trend change of annual maximum and minimum temperature were also analyzed using ensemble projections. The results shows that: (1)The downscaling model had a good applicability on reproducing daily and monthly mean maximum and minimum temperature over the whole basin. (2) Bias was observed when using historical predictors from CMIP5 models and the performance of CNRM-CM5 was a little worse than that of MPI-ESM-LR. (3) The change in annual mean maximum and minimum temperature under the two scenarios in 2020s, 2050s and 2070s will increase and magnitude of maximum temperature will be higher than minimum temperature. (4) The increase in temperature in the mountains and along the coastline is remarkably high than the other parts of the studies basin. (5) For annual maximum and minimum temperature, the significant upward trend will be obtained under RCP 8.5 scenario and the magnitude will be 0.37 and 0.39 ℃ per decade, respectively; the increase in magnitude under RCP 2.6 scenario will be upward in 2020s and then decrease in 2050s and 2070s, and the magnitude will be 0.01 and 0.01℃ per decade, respectively.

Optimum performance of explosives in a quasistatic detonation cycle

NASA Astrophysics Data System (ADS)

Baker, Ernest L.; Stiel, Leonard I.

2017-01-01

Analyses were conducted on the behavior of explosives in a quasistatic detonation cycle. This type of cycle has been proposed for the determination of the maximum work that can be performed by the explosive. The Jaguar thermochemical equilibrium program enabled the direct analyses of explosive performance at the various steps in the detonation cycle. In all cases the explosive is initially detonated to a point on the Hugoniot curve for the reaction products. The maximum useful work that can be obtained from the explosive is equal to the P-V work on the isentrope for expansion after detonation to atmospheric pressure, minus one-half the square of the particle velocity at the detonation point. This quantity is calculated form the internal energy of the explosive at the initial and final atmospheric temperatures. Cycle efficiencies (net work/ heat added) are also calculated with these procedures. For several explosives including TNT, RDX, and aluminized compositions, maximum work effects were established through the Jaguar calculations for Hugoniot points corresponding to C-J, overdriven, underdriven and constant volume detonations. Detonation to the C-J point is found to result in the maximum net work in all cases.

A pairwise maximum entropy model accurately describes resting-state human brain networks

PubMed Central

Watanabe, Takamitsu; Hirose, Satoshi; Wada, Hiroyuki; Imai, Yoshio; Machida, Toru; Shirouzu, Ichiro; Konishi, Seiki; Miyashita, Yasushi; Masuda, Naoki

2013-01-01

The resting-state human brain networks underlie fundamental cognitive functions and consist of complex interactions among brain regions. However, the level of complexity of the resting-state networks has not been quantified, which has prevented comprehensive descriptions of the brain activity as an integrative system. Here, we address this issue by demonstrating that a pairwise maximum entropy model, which takes into account region-specific activity rates and pairwise interactions, can be robustly and accurately fitted to resting-state human brain activities obtained by functional magnetic resonance imaging. Furthermore, to validate the approximation of the resting-state networks by the pairwise maximum entropy model, we show that the functional interactions estimated by the pairwise maximum entropy model reflect anatomical connexions more accurately than the conventional functional connectivity method. These findings indicate that a relatively simple statistical model not only captures the structure of the resting-state networks but also provides a possible method to derive physiological information about various large-scale brain networks. PMID:23340410

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

NASA Astrophysics Data System (ADS)

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

2017-07-01

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

Motor vehicle driver death and high state maximum speed limits: 1991-1993.

PubMed

Yamane, Grover K; Bradshaw, Benjamin S

2008-09-01

To measure the association between motor vehicle crash (MVC) driver death and high state maximum speed limits. This study used a case-control design and assessed driver deaths from three major types of MVCs: non-collision; collision with motor vehicles in transit; and collision with stationary objects. The study period was 1991-1993. For each type of crash, case subject populations of fatally injured drivers were obtained from the U.S. Department of Transportation Fatality Analysis Reporting System. Four control subject populations, each associated with a different cause of death, were obtained from a U.S. national death certificate database (the causes of death were unintentional poisoning, non-Hodgkin lymphoma, drowning, and diabetes mellitus). Subjects were considered exposed if the state in which they crashed (for cases) or died (for controls) had a maximum speed limit greater than 55 mph. Each of the three case subject populations was compared against each of the four control subject populations. Odds ratios (ORs) were adjusted for age and gender. For non-collision driver death, ORs ranged from 3.06 to 6.56, depending on the year and control group; all the ORs were significant. For collision with motor vehicles in transit driver death, ORs ranged from 1.12 to 2.22; all the ORs were significant. For collision with stationary objects driver death, ORs ranged from 0.87 to 1.83. There was a moderately strong and significant association between non-collision driver death and high state maximum speed limits. For collision with motor vehicles in transit driver death, the association was somewhat milder but still consistent. For collision with stationary objects driver death, the presence of an association was unclear. During 1991-1993, the effects of high state maximum speed limits may have been different for different types of MVCs.

Influence of Distributed Dead Loads on Vehicle Position for Maximum Moment in Simply Supported Bridges

NASA Astrophysics Data System (ADS)

Gupta, Tanmay; Kumar, Manoj

2017-06-01

Usually, the design moments in the simply supported bridges are obtained as the sum of moments due to dead loads and live load where the live load moments are calculated using the rolling load concept neglecting the effect of dead loads. For the simply supported bridges, uniformly distributed dead load produces maximum moment at mid-span while the absolute maximum bending moment due to multi-axel vehicles occur under a wheel which usually do not lie at mid-span. Since, the location of absolute maximum bending moment due to multi-axel vehicle do not coincide with the location of maximum moment due to dead loads occurring at mid-span, the design moment may not be obtained by simply superimposing the effect of dead load and live load. Moreover, in case of Class-A and Class-70R wheeled vehicular live loads, which consists of several axels, the number of axels to be considered over the bridge of given span and their location is tedious to find out and needs several trials. The aim of the present study is to find the number of wheels for Class-A and Class-70R wheeled vehicles and their precise location to produce absolute maximum moment in the bridge considering the effect of dead loads and impact factor. Finally, in order to enable the designers, the design moments due to Class-70R wheeled and Class-A loading have been presented in tabular form for the spans from 10 to 50 m.

Numerical and experimental study of actuator performance on piezoelectric microelectromechanical inkjet print head.

PubMed

Van So, Pham; Jun, Hyun Woo; Lee, Jaichan

2013-12-01

We have investigated the actuator performance of a piezoelectrically actuated inkjet print head via the numerical and experimental analysis. The actuator consisting of multi-layer membranes, such as piezoelectric, elastic and other buffer layers, and ink chamber was fabricated by MEMS processing. The maximum displacement of the actuator membrane obtained in the experiment is explained by numerical analysis. A simulation of the actuator performance with fluidic damping shows that the resonant frequency of the membrane in liquid is reduced from its resonant frequency in air by a factor of three, which was also verified in the experiment. These simulation and experimental studies demonstrate how much "dynamic force," in terms of a membrane's maximum displacement, maximum force and driving frequency, can be produced by an actuator membrane interacting with fluid.

20 CFR 229.48 - Family maximum.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Family maximum. 229.48 Section 229.48... OVERALL MINIMUM GUARANTEE Computation of the Overall Minimum Rate § 229.48 Family maximum. (a) Family... month on one person's earnings record is limited. This limited amount is called the family maximum. The...

49 CFR 107.329 - Maximum penalties.

Code of Federal Regulations, 2012 CFR

2012-10-01

... maximum civil penalty is $110,000 if the violation results in death, serious illness or severe injury to... 49 Transportation 2 2012-10-01 2012-10-01 false Maximum penalties. 107.329 Section 107.329... PROGRAM PROCEDURES Enforcement Compliance Orders and Civil Penalties § 107.329 Maximum penalties. (a) A...

49 CFR 107.329 - Maximum penalties.

Code of Federal Regulations, 2010 CFR

2010-10-01

... maximum civil penalty is $110,000 if the violation results in death, serious illness or severe injury to... 49 Transportation 2 2010-10-01 2010-10-01 false Maximum penalties. 107.329 Section 107.329... PROGRAM PROCEDURES Enforcement Compliance Orders and Civil Penalties § 107.329 Maximum penalties. (a) A...

49 CFR 107.329 - Maximum penalties.

Code of Federal Regulations, 2011 CFR

2011-10-01

... maximum civil penalty is $110,000 if the violation results in death, serious illness or severe injury to... 49 Transportation 2 2011-10-01 2011-10-01 false Maximum penalties. 107.329 Section 107.329... PROGRAM PROCEDURES Enforcement Compliance Orders and Civil Penalties § 107.329 Maximum penalties. (a) A...

Efficient heuristics for maximum common substructure search.

PubMed

Englert, Péter; Kovács, Péter

2015-05-26

Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results.

34 CFR 674.12 - Loan maximums.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Loan maximums. 674.12 Section 674.12 Education..., DEPARTMENT OF EDUCATION FEDERAL PERKINS LOAN PROGRAM General Provisions § 674.12 Loan maximums. (a) The maximum annual amount of Federal Perkins Loans and NDSLs an eligible student may borrow is— (1) $5,500 for...

49 CFR 190.223 - Maximum penalties.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Maximum penalties. 190.223 Section 190.223... PROCEDURES Enforcement Civil Penalties § 190.223 Maximum penalties. (a) Any person who is determined to have... except that the maximum civil penalty may not exceed $1,000,000 for any related series of violations. (b...

14 CFR 1261.102 - Maximum amount.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Maximum amount. 1261.102 Section 1261.102...) Employees' Personal Property Claims § 1261.102 Maximum amount. From October 1, 1982, to October 30, 1988, the maximum amount that may be paid under the Military Personnel and Civilian Employees' Claim Act of...

20 CFR 211.14 - Maximum creditable compensation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Maximum creditable compensation. 211.14... CREDITABLE RAILROAD COMPENSATION § 211.14 Maximum creditable compensation. Maximum creditable compensation for calendar years after 1984 is the maximum annual taxable wage base defined in section 3231(e)(2)(B...

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) The draft...) The draft of a vessel shall not, in any case, exceed 79.2 dm or the maximum permissible draft...

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) The draft...) The draft of a vessel shall not, in any case, exceed 79.2 dm or the maximum permissible draft...

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) The draft...) The draft of a vessel shall not, in any case, exceed 79.2 dm or the maximum permissible draft...

Parametric performance of circumferentially grooved heat pipes with homogeneous and graded-porosity slab wicks at cryogenic temperatures. [methane and ethane working fluids

NASA Technical Reports Server (NTRS)

Groll, M.; Pittman, R. B.; Eninger, J. E.

1976-01-01

A recently developed, potentially high-performance nonarterial wick was extensively tested. This slab wick has an axially varying porosity which can be tailored to match the local stress imposed on the wick. The purpose of the tests was to establish the usefulness of the graded-porosity slab wick at cryogenic temperatures between 110 and 260 K, with methane and ethane as working fluids. For comparison, a homogeneous (i.e., uniform porosity) slab wick was also tested. The tests included: maximum heat pipe performance as a function of fluid inventory, maximum performance as a function of operating temperature, maximum performance as a function of evaporator elevation, and influence of slab wick orientation on performance. The experimental data were compared with theoretical predictions obtained with the GRADE computer program.

24 CFR 941.306 - Maximum project cost.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Maximum project cost. 941.306... DEVELOPMENT PUBLIC HOUSING DEVELOPMENT Application and Proposal § 941.306 Maximum project cost. (a) Calculation of maximum project cost. The maximum project cost represents the total amount of public housing...

24 CFR 941.306 - Maximum project cost.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Maximum project cost. 941.306... DEVELOPMENT PUBLIC HOUSING DEVELOPMENT Application and Proposal § 941.306 Maximum project cost. (a) Calculation of maximum project cost. The maximum project cost represents the total amount of public housing...

20 CFR 226.51 - Maximum monthly amount.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Maximum monthly amount. 226.51 Section 226.51... EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Railroad Retirement Family Maximum § 226.51 Maximum monthly amount. The railroad retirement family maximum is equal to an employee's “final average monthly...

Maximum step length: relationships to age and knee and hip extensor capacities.

PubMed

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2007-07-01

Maximum Step Length may be used to identify older adults at increased risk for falls. Since leg muscle weakness is a risk factor for falls, we tested the hypotheses that maximum knee and hip extension speed, strength, and power capacities would significantly correlate with Maximum Step Length and also that the "step out and back" Maximum Step Length [Medell, J.L., Alexander, N.B., 2000. A clinical measure of maximal and rapid stepping in older women. J. Gerontol. A Biol. Sci. Med. Sci. 55, M429-M433.] would also correlate with the Maximum Step Length of its two sub-tasks: stepping "out only" and stepping "back only". These sub-tasks will be referred to as versions of Maximum Step Length. Unimpaired younger (N=11, age=24[3]years) and older (N=10, age=73[5]years) women performed the above three versions of Maximum Step Length. Knee and hip extension speed, strength, and power capacities were determined on a separate day and regressed on Maximum Step Length and age group. Version and practice effects were quantified and subjective impressions of test difficulty recorded. Hypotheses were tested using linear regressions, analysis of variance, and Fisher's exact test. Maximum Step Length explained 6-22% additional variance in knee and hip extension speed, strength, and power capacities after controlling for age group. Within- and between-block and test-retest correlation values were high (>0.9) for all test versions. Shorter Maximum Step Lengths are associated with reduced knee and hip extension speed, strength, and power capacities after controlling for age. A single out-and-back step of maximal length is a feasible, rapid screening measure that may provide insight into underlying functional impairment, regardless of age.

Theoretical Analysis of Maximum Flow Declination Rate versus Maximum Area Declination Rate in Phonation

ERIC Educational Resources Information Center

Titze, Ingo R.

2006-01-01

Purpose: Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal airflow waveform, is in part attributable to the maximum area declination rate (MADR) and in part to the overall inertia of the air column of the vocal tract (lungs to…

49 CFR 230.24 - Maximum allowable stress.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

49 CFR 230.24 - Maximum allowable stress.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

49 CFR 230.24 - Maximum allowable stress.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

49 CFR 230.24 - Maximum allowable stress.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

49 CFR 230.24 - Maximum allowable stress.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

14 CFR 23.1527 - Maximum operating altitude.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established for...

Performance tests of a single-cylinder compression-ignition engine with a displacer piston

NASA Technical Reports Server (NTRS)

Moore, C S; Foster, H H

1935-01-01

Engine performance was investigated using a rectangular displacer on the piston crown to cause a forced air flow in a vertical-disk combustion chamber of a single-cylinder, 4-stroke-cycle compression-ignition engine. The optimum air-flow area was determined first with the area concentrated at one end of the displacer and then with the area equally divided between two passages, one at each end of the displacer. Best performance was obtained with the two-passage air flow arranged to give a calculated maximum air-flow speed of 8 times the linear crank-pin speed. With the same fuel-spray formation as used without the air flow, the maximum clear exhaust brake mean effective pressure at 1,500 r.p.m. was increased from 90 to 115 pounds per square inch and the corresponding fuel consumption reduced from 0.46 to 0.43 pound per brake horsepower-hour. At 1,200 r.p.m., a maximum clear exhaust brake mean effective pressure of 120 pounds per square inch was obtained at a fuel consumption of 0.42 pound per brake horsepower-hour. At higher specific fuel consumption the brake mean effective pressure was still increasing rapidly.

Multi-Group Maximum Entropy Model for Translational Non-Equilibrium

NASA Technical Reports Server (NTRS)

Jayaraman, Vegnesh; Liu, Yen; Panesi, Marco

2017-01-01

The aim of the current work is to describe a new model for flows in translational non- equilibrium. Starting from the statistical description of a gas proposed by Boltzmann, the model relies on a domain decomposition technique in velocity space. Using the maximum entropy principle, the logarithm of the distribution function in each velocity sub-domain (group) is expressed with a power series in molecular velocity. New governing equations are obtained using the method of weighted residuals by taking the velocity moments of the Boltzmann equation. The model is applied to a spatially homogeneous Boltzmann equation with a Bhatnagar-Gross-Krook1(BGK) model collision operator and the relaxation of an initial non-equilibrium distribution to a Maxwellian is studied using the model. In addition, numerical results obtained using the model for a 1D shock tube problem are also reported.

Minimum maximum temperature gradient coil design.

PubMed

While, Peter T; Poole, Michael S; Forbes, Larry K; Crozier, Stuart

2013-08-01

Ohmic heating is a serious problem in gradient coil operation. A method is presented for redesigning cylindrical gradient coils to operate at minimum peak temperature, while maintaining field homogeneity and coil performance. To generate these minimaxT coil windings, an existing analytic method for simulating the spatial temperature distribution of single layer gradient coils is combined with a minimax optimization routine based on sequential quadratic programming. Simulations are provided for symmetric and asymmetric gradient coils that show considerable improvements in reducing maximum temperature over existing methods. The winding patterns of the minimaxT coils were found to be heavily dependent on the assumed thermal material properties and generally display an interesting "fish-eye" spreading of windings in the dense regions of the coil. Small prototype coils were constructed and tested for experimental validation and these demonstrate that with a reasonable estimate of material properties, thermal performance can be improved considerably with negligible change to the field error or standard figures of merit. © 2012 Wiley Periodicals, Inc.

The variation in frequency locations in Doppler ultrasound spectra for maximum blood flow velocities in narrowed vessels.

PubMed

Zhang, Yingyun; Zhang, Yufeng; Gao, Lian; Deng, Li; Hu, Xiao; Zhang, Kexin; Li, Haiyan

2017-11-01

This study assessed the variation in the frequency locations in the Doppler ultrasound spectra for the maximum blood flow velocities of in vessels with different degrees of bilaterally axisymmetric stenosis. This was done by comparing the relationship between the velocity distributions and corresponding Doppler power spectra. First, a geometric vessel model with axisymmetric stenosis was established. This made it possible to obtain the blood flow velocity distributions for different degrees of stenosis from the solutions of the Navier-Stokes equations. Then, the Doppler spectra were calculated for the entire segment of the vessel that was covered by the sound field. Finally, the maximum frequency locations for the spectra were determined based on the intersections of the maximum values chosen from the calculated blood flow velocity distributions and their corresponding spectra. The computational analysis showed that the maximum frequencies, which corresponded to the maximum blood flow velocities for different degrees of stenosis, were located at different positions along the spectral falling edges. The location for a normal (stenosis free) vessel was in the middle of the falling edge. For vessels with increasing degrees of stenosis, this location shifted approximately linearly downward along the falling edge. For 40% stenosis, the location reached a position at the falling edge of 0.32. Results obtained using the Field II simulation tool demonstrated the validity of the theoretical analysis and calculations, and may help to improve the maximum velocity estimation accuracy for Doppler blood flow spectra in stenosed vessels. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Collinear Latent Variables in Multilevel Confirmatory Factor Analysis: A Comparison of Maximum Likelihood and Bayesian Estimations.

PubMed

Can, Seda; van de Schoot, Rens; Hox, Joop

2015-06-01

Because variables may be correlated in the social and behavioral sciences, multicollinearity might be problematic. This study investigates the effect of collinearity manipulated in within and between levels of a two-level confirmatory factor analysis by Monte Carlo simulation. Furthermore, the influence of the size of the intraclass correlation coefficient (ICC) and estimation method; maximum likelihood estimation with robust chi-squares and standard errors and Bayesian estimation, on the convergence rate are investigated. The other variables of interest were rate of inadmissible solutions and the relative parameter and standard error bias on the between level. The results showed that inadmissible solutions were obtained when there was between level collinearity and the estimation method was maximum likelihood. In the within level multicollinearity condition, all of the solutions were admissible but the bias values were higher compared with the between level collinearity condition. Bayesian estimation appeared to be robust in obtaining admissible parameters but the relative bias was higher than for maximum likelihood estimation. Finally, as expected, high ICC produced less biased results compared to medium ICC conditions.

High dose rates obtained outside ISS in June 2015 during SEP event.

PubMed

Dachev, T P; Tomov, B T; Matviichuk, Yu N; Dimitrov, Pl G; Bankov, N G

2016-06-01

The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform outside the Russian "Zvezda" module of the International Space Station (ISS) in the period 24 October 2014-11 January 2016. It is the Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2015a). Took place in November 2014, this was the first attempt to monitor a small solar energetic particle (SEP) event outside ISS using the Liulin-type DES (Dachev et al., 2015d). In this study, we describe the dosimetric characteristics of the largest SEP event, observed on 22 June 2015 with the R3DR2 instrument outside ISS. The main finding of this study is that SEP protons with a minimum energy of approximately 7MeV at the surface of the R3DR2 detector produced high dose rates, reaching >5000µGyh(-1), while the inner radiation belt maximum dose was at the level of 2200µGyh(-1). If a virtual external vehicle activity (EVA) was performed in the same period of the SEP maximum on 22 June 2015, the doses obtained in the skin of cosmonauts/astronauts can reach 2.84mGy after 6.5h, which is similar to the average absorbed dose inside ISS for 15days (Reitz et al., 2005). A comparison with other extreme events measured with Liulin-type instruments shows that SEPs similar to that observed on 22 June 2015 could be one of the most dangerous events for the cosmonauts/astronauts involved in EVA. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Does respiratory muscle training increase physical performance?

PubMed

Sperlich, Billy; Fricke, Hannes; de Marées, Markus; Linville, John W; Mester, Joachim

2009-09-01

Special force units and military personnel undergo demanding physical exercise and might benefit from high-intensity respiratory muscle training (RMT) by increasing their endurance performance. This study examined the effects of a 6-week high-intensity RMT on running performance and oxygen uptake (VO2max) in a group of German Special Force Squad members. 17 participants were randomly assigned to a training or control group. Baseline and post-testing included a ramp test, as well as an incremental test on a treadmill, performed to physical exhaustion. VO2, respiratory exchange ratio, and heart rate were measured breath by breath. Furthermore, maximum running speed (V(max)), 4 mmol x 1(-1) lactate threshold (V4) and perception of respiratory effort were determined. During pulmonary testing, sustained maximum inspiratory and expiratory pressure (PI(max) and PE(max)) were obtained. RMT was performed daily at approximately 90% PI(max) for 6 weeks with 2 x 30 breath cycles using an Ultrabreathe lung trainer. No statistical differences were detected between the groups for any parameter after RMT. High-intensity RMT did not show any benefits on VO2max and endurance performance and are unlikely to be of benefit to military or paramilitary training programs for an increase in endurance performance.

Calculations of the Performance of a Compression-Ignition Engine-Compressor Turbine Combination I : Performance of a Highly Supercharged Compression-Ignition Engine

NASA Technical Reports Server (NTRS)

Sanders, J. C.; Mendelson, Alexander

1945-01-01

Small high-speed single-cylinder compression-ignition engines were tested to determine their performance characteristics under high supercharging. Calculations were made on the energy available in the exhaust gas of the compression-ignition engines. The maximum power at any given maximum cylinder pressure was obtained when the compression pressure was equal to the maximum cylinder pressure. Constant-pressure combustion was found possible at an engine speed of 2200 rpm. Exhaust pressures and temperatures were determined from an analysis of indicator cards. The analysis showed that, at rich mixtures with the exhaust back pressure equal to the inlet-air pressure, there is excess energy available for driving a turbine over that required for supercharging. The presence of this excess energy indicates that a highly supercharged compression-ignition engine might be desirable as a compressor and combustion chamber for a turbine.

Determination of the maximum MGS mounting height : phase II detailed analysis with LS-DYNA.

DOT National Transportation Integrated Search

2012-12-01

Determination of the maximum Midwest Guardrail System (MGS) mounting height was performed in two phases. : Phase I concentrated on crash testing: two full-scale crash tests were performed on the MGS with top-rail mounting heights : of 34 in. (864 mm)...

Determination of the Maximum Control Forces and Attainable Quickness in the Operation of Airplane Controls

NASA Technical Reports Server (NTRS)

Hertel, Heinrich

1930-01-01

This report is intended to furnish bases for load assumptions in the designing of airplane controls. The maximum control forces and quickness of operation are determined. The maximum forces for a strong pilot with normal arrangement of the controls is taken as 1.25 times the mean value obtained from tests with twelve persons. Tests with a number of persons were expected to show the maximum forces that a man of average strength can exert on the control stick in operating the elevator and ailerons and also on the rudder bar. The effect of fatigue, of duration and of the nature (static or dynamic) of the force, as also the condition of the test subject (with or without belt) were also considered.

Dynamic Programming and Error Estimates for Stochastic Control Problems with Maximum Cost

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bokanowski, Olivier, E-mail: boka@math.jussieu.fr; Picarelli, Athena, E-mail: athena.picarelli@inria.fr; Zidani, Hasnaa, E-mail: hasnaa.zidani@ensta.fr

2015-02-15

This work is concerned with stochastic optimal control for a running maximum cost. A direct approach based on dynamic programming techniques is studied leading to the characterization of the value function as the unique viscosity solution of a second order Hamilton–Jacobi–Bellman (HJB) equation with an oblique derivative boundary condition. A general numerical scheme is proposed and a convergence result is provided. Error estimates are obtained for the semi-Lagrangian scheme. These results can apply to the case of lookback options in finance. Moreover, optimal control problems with maximum cost arise in the characterization of the reachable sets for a system ofmore » controlled stochastic differential equations. Some numerical simulations on examples of reachable analysis are included to illustrate our approach.« less

12-mode OFDM transmission using reduced-complexity maximum likelihood detection.

PubMed

Lobato, Adriana; Chen, Yingkan; Jung, Yongmin; Chen, Haoshuo; Inan, Beril; Kuschnerov, Maxim; Fontaine, Nicolas K; Ryf, Roland; Spinnler, Bernhard; Lankl, Berthold

2015-02-01

We report the transmission of 163-Gb/s MDM-QPSK-OFDM and 245-Gb/s MDM-8QAM-OFDM transmission over 74 km of few-mode fiber supporting 12 spatial and polarization modes. A low-complexity maximum likelihood detector is employed to enhance the performance of a system impaired by mode-dependent loss.

Impact of marine reserve on maximum sustainable yield in a traditional prey-predator system

NASA Astrophysics Data System (ADS)

Paul, Prosenjit; Kar, T. K.; Ghorai, Abhijit

2018-01-01

Multispecies fisheries management requires managers to consider the impact of fishing activities on several species as fishing impacts both targeted and non-targeted species directly or indirectly in several ways. The intended goal of traditional fisheries management is to achieve maximum sustainable yield (MSY) from the targeted species, which on many occasions affect the targeted species as well as the entire ecosystem. Marine reserves are often acclaimed as the marine ecosystem management tool. Few attempts have been made to generalize the ecological effects of marine reserve on MSY policy. We examine here how MSY and population level in a prey-predator system are affected by the low, medium and high reserve size under different possible scenarios. Our simulation works shows that low reserve area, the value of MSY for prey exploitation is maximum when both prey and predator species have fast movement rate. For medium reserve size, our analysis revealed that the maximum value of MSY for prey exploitation is obtained when prey population has fast movement rate and predator population has slow movement rate. For high reserve area, the maximum value of MSY for prey's exploitation is very low compared to the maximum value of MSY for prey's exploitation in case of low and medium reserve. On the other hand, for low and medium reserve area, MSY for predator exploitation is maximum when both the species have fast movement rate.

Gauging the Nearness and Size of Cycle Maximum

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.

2003-01-01

A simple method for monitoring the nearness and size of conventional cycle maximum for an ongoing sunspot cycle is examined. The method uses the observed maximum daily value and the maximum monthly mean value of international sunspot number and the maximum value of the 2-mo moving average of monthly mean sunspot number to effect the estimation. For cycle 23, a maximum daily value of 246, a maximum monthly mean of 170.1, and a maximum 2-mo moving average of 148.9 were each observed in July 2000. Taken together, these values strongly suggest that conventional maximum amplitude for cycle 23 would be approx. 124.5, occurring near July 2002 +/-5 mo, very close to the now well-established conventional maximum amplitude and occurrence date for cycle 23-120.8 in April 2000.

Maximum Likelihood Time-of-Arrival Estimation of Optical Pulses via Photon-Counting Photodetectors

NASA Technical Reports Server (NTRS)

Erkmen, Baris I.; Moision, Bruce E.

2010-01-01

Many optical imaging, ranging, and communications systems rely on the estimation of the arrival time of an optical pulse. Recently, such systems have been increasingly employing photon-counting photodetector technology, which changes the statistics of the observed photocurrent. This requires time-of-arrival estimators to be developed and their performances characterized. The statistics of the output of an ideal photodetector, which are well modeled as a Poisson point process, were considered. An analytical model was developed for the mean-square error of the maximum likelihood (ML) estimator, demonstrating two phenomena that cause deviations from the minimum achievable error at low signal power. An approximation was derived to the threshold at which the ML estimator essentially fails to provide better than a random guess of the pulse arrival time. Comparing the analytic model performance predictions to those obtained via simulations, it was verified that the model accurately predicts the ML performance over all regimes considered. There is little prior art that attempts to understand the fundamental limitations to time-of-arrival estimation from Poisson statistics. This work establishes both a simple mathematical description of the error behavior, and the associated physical processes that yield this behavior. Previous work on mean-square error characterization for ML estimators has predominantly focused on additive Gaussian noise. This work demonstrates that the discrete nature of the Poisson noise process leads to a distinctly different error behavior.

Preliminary Investigation of Performance and Starting Characteristics of Liquid Fluorine : Liquid Oxygen Mixtures with Jet Fuel

NASA Technical Reports Server (NTRS)

Rothenberg, Edward A; Ordin, Paul M

1954-01-01

The performance of jet fuel with an oxidant mixture containing 70 percent liquid fluorine and 30 percent liquid oxygen by weight was investigated in a 500-pound-thrust engine operating at a chamber pressure of 300 pounds per square inch absolute. A one-oxidant-on-one-fuel skewed-hole impinging-jet injector was evaluated in a chamber of characteristic length equal to 50 inches. A maximum experimental specific impulse of 268 pound-seconds per pound was obtained at 25 percent fuel, which corresponds to 96 percent of the maximum theoretical specific impulse based on frozen composition expansion. The maximum characteristic velocity obtained was 6050 feet per second at 23 percent fuel, or 94 percent of the theoretical maximum. The average thrust coefficient was 1.38 for the 500-pound thrust combustion-chamber nozzle used, which was 99 percent of the theoretical (frozen) maximum. Mixtures of fluorine and oxygen were found to be self-igniting with jet fuel with fluorine concentrations as low as 4 percent, when low starting propellant flow rated were used.

Maximum von Mises Stress in the Loading Environment of Mass Acceleration Curve

NASA Technical Reports Server (NTRS)

Glaser, Robert J.; Chen, Long Y.

2006-01-01

Method for calculating stress due to acceleration loading: 1) Part has been designed by FEA and hand calculation in one critical loading direction judged by the analyst; 2) Maximum stress can be due to loading in another direction; 3) Analysis procedure to be presented determines: a) The maximum Mises stress at any point; and b) The direction of maximum loading associated with the "stress". Concept of Mass Acceleration Curves (MAC): 1) Developed by JPL to perform preliminary structural sizing (i.e. Mariners, Voyager, Galileo, Pathfinder, MER,...MSL); 2) Acceleration of physical masses are bounded by a curve; 3) G-levels of vibro-acoustic and transient environments; 4) Convergent process before the couple loads cycle; and 5) Semi-empirical method to effectively bound the loads, not a simulation of the actual response.

Target-adaptive polarimetric synthetic aperture radar target discrimination using maximum average correlation height filters.

PubMed

Sadjadi, Firooz A; Mahalanobis, Abhijit

2006-05-01

We report the development of a technique for adaptive selection of polarization ellipse tilt and ellipticity angles such that the target separation from clutter is maximized. From the radar scattering matrix [S] and its complex components, in phase and quadrature phase, the elements of the Mueller matrix are obtained. Then, by means of polarization synthesis, the radar cross section of the radar scatters are obtained at different transmitting and receiving polarization states. By designing a maximum average correlation height filter, we derive a target versus clutter distance measure as a function of four transmit and receive polarization state angles. The results of applying this method on real synthetic aperture radar imagery indicate a set of four transmit and receive angles that lead to maximum target versus clutter discrimination. These optimum angles are different for different targets. Hence, by adaptive control of the state of polarization of polarimetric radar, one can noticeably improve the discrimination of targets from clutter.

Optimum Projection Angle for Attaining Maximum Distance in a Soccer Punt Kick

PubMed Central

Linthorne, Nicholas P.; Patel, Dipesh S.

2011-01-01

To produce the greatest horizontal distance in a punt kick the ball must be projected at an appropriate angle. Here, we investigated the optimum projection angle that maximises the distance attained in a punt kick by a soccer goalkeeper. Two male players performed many maximum-effort kicks using projection angles of between 10° and 90°. The kicks were recorded by a video camera at 100 Hz and a 2 D biomechanical analysis was conducted to obtain measures of the projection velocity, projection angle, projection height, ball spin rate, and foot velocity at impact. The player’s optimum projection angle was calculated by substituting mathematical equations for the relationships between the projection variables into the equations for the aerodynamic flight of a soccer ball. The calculated optimum projection angles were in agreement with the player’s preferred projection angles (40° and 44°). In projectile sports even a small dependence of projection velocity on projection angle is sufficient to produce a substantial shift in the optimum projection angle away from 45°. In the punt kicks studied here, the optimum projection angle was close to 45° because the projection velocity of the ball remained almost constant across all projection angles. This result is in contrast to throwing and jumping for maximum distance, where the projection velocity the athlete is able to achieve decreases substantially with increasing projection angle and so the optimum projection angle is well below 45°. Key points The optimum projection angle that maximizes the distance of a punt kick by a soccer goalkeeper is about 45°. The optimum projection angle is close to 45° because the projection velocity of the ball is almost the same at all projection angles. This result is in contrast to throwing and jumping for maximum distance, where the optimum projection angle is well below 45° because the projection velocity the athlete is able to achieve decreases substantially with increasing

Consistent maximum entropy representations of pipe flow networks

NASA Astrophysics Data System (ADS)

Waldrip, Steven H.; Niven, Robert K.; Abel, Markus; Schlegel, Michael

2017-06-01

The maximum entropy method is used to predict flows on water distribution networks. This analysis extends the water distribution network formulation of Waldrip et al. (2016) Journal of Hydraulic Engineering (ASCE), by the use of a continuous relative entropy defined on a reduced parameter set. This reduction in the parameters that the entropy is defined over ensures consistency between different representations of the same network. The performance of the proposed reduced parameter method is demonstrated with a one-loop network case study.

Modeling the impact of the indigenous microbial population on the maximum population density of Salmonella on alfalfa.

PubMed

Rijgersberg, Hajo; Franz, Eelco; Nierop Groot, Masja; Tromp, Seth-Oscar

2013-07-01

Within a microbial risk assessment framework, modeling the maximum population density (MPD) of a pathogenic microorganism is important but often not considered. This paper describes a model predicting the MPD of Salmonella on alfalfa as a function of the initial contamination level, the total count of the indigenous microbial population, the maximum pathogen growth rate and the maximum population density of the indigenous microbial population. The model is parameterized by experimental data describing growth of Salmonella on sprouting alfalfa seeds at inoculum size, native microbial load and Pseudomonas fluorescens 2-79. The obtained model fits well to the experimental data, with standard errors less than ten percent of the fitted average values. The results show that the MPD of Salmonella is not only dictated by performance characteristics of Salmonella but depends on the characteristics of the indigenous microbial population like total number of cells and its growth rate. The model can improve the predictions of microbiological growth in quantitative microbial risk assessments. Using this model, the effects of preventive measures to reduce pathogenic load and a concurrent effect on the background population can be better evaluated. If competing microorganisms are more sensitive to a particular decontamination method, a pathogenic microorganism may grow faster and reach a higher level. More knowledge regarding the effect of the indigenous microbial population (size, diversity, composition) of food products on pathogen dynamics is needed in order to make adequate predictions of pathogen dynamics on various food products.

Accounting for mudflow genesis in preliminary assessment of the maximum volume of solid mudflow sediments in the North Caucasus

NASA Astrophysics Data System (ADS)

Zalikhanov, M. Ch.; Kondratieva, N. V.; Adzhiev, A. Kh.; Razumov, V. V.

2016-09-01

The area of investigation was subject to multifactor analysis of the relationship between the maximum amount of mudflow solid sediments ( W) and parameters such as the mudflow basin area ( S), average channel slope (α), and mudflow channel length ( L). They were used to obtain analytical expressions in order to approximate the W( S, L, α) relation based on the mudflow genesis and source height. Statistical data on mudflow manifestations in different basins in the North Caucasus covering more than fifty years were used to obtain the analytical expressions in order to assess the maximum volume of mudflow solid sediments.

On the maximum drawdown during speculative bubbles

NASA Astrophysics Data System (ADS)

Rotundo, Giulia; Navarra, Mauro

2007-08-01

A taxonomy of large financial crashes proposed in the literature locates the burst of speculative bubbles due to endogenous causes in the framework of extreme stock market crashes, defined as falls of market prices that are outlier with respect to the bulk of drawdown price movement distribution. This paper goes on deeper in the analysis providing a further characterization of the rising part of such selected bubbles through the examination of drawdown and maximum drawdown movement of indices prices. The analysis of drawdown duration is also performed and it is the core of the risk measure estimated here.

Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

NASA Technical Reports Server (NTRS)

Reynolds, R. G.; Markley, F. Landis

2001-01-01

Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum which the wheels can provide. For an n-wheel configuration, the torque or momentum envelope can be obtained by projecting the n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, into three dimensional space via the 3xn matrix of wheel axes. In this paper, the properties of the projected hypercube are discussed, and algorithms are proposed for determining this maximal torque or momentum envelope for general wheel configurations. Practical implementation strategies for specific wheel configurations are also considered.

Active impulsive noise control using maximum correntropy with adaptive kernel size

NASA Astrophysics Data System (ADS)

Lu, Lu; Zhao, Haiquan

2017-03-01

The active noise control (ANC) based on the principle of superposition is an attractive method to attenuate the noise signals. However, the impulsive noise in the ANC systems will degrade the performance of the controller. In this paper, a filtered-x recursive maximum correntropy (FxRMC) algorithm is proposed based on the maximum correntropy criterion (MCC) to reduce the effect of outliers. The proposed FxRMC algorithm does not requires any priori information of the noise characteristics and outperforms the filtered-x least mean square (FxLMS) algorithm for impulsive noise. Meanwhile, in order to adjust the kernel size of FxRMC algorithm online, a recursive approach is proposed through taking into account the past estimates of error signals over a sliding window. Simulation and experimental results in the context of active impulsive noise control demonstrate that the proposed algorithms achieve much better performance than the existing algorithms in various noise environments.

Direct tests of a pixelated microchannel plate as the active element of a shower maximum detector

DOE PAGES

Apresyan, A.; Los, S.; Pena, C.; ...

2016-05-07

One possibility to make a fast and radiation resistant shower maximum detector is to use a secondary emitter as an active element. We report our studies of microchannel plate photomultipliers (MCPs) as the active element of a shower-maximum detector. We present test beam results obtained using Photonis XP85011 to detect secondary particles of an electromagnetic shower. We focus on the use of the multiple pixels on the Photonis MCP in order to find a transverse two-dimensional shower distribution. A spatial resolution of 0.8 mm was obtained with an 8 GeV electron beam. As a result, a method for measuring themore » arrival time resolution for electromagnetic showers is presented, and we show that time resolution better than 40 ps can be achieved.« less

Direct tests of a pixelated microchannel plate as the active element of a shower maximum detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Apresyan, A.; Los, S.; Pena, C.

One possibility to make a fast and radiation resistant shower maximum detector is to use a secondary emitter as an active element. We report our studies of microchannel plate photomultipliers (MCPs) as the active element of a shower-maximum detector. We present test beam results obtained using Photonis XP85011 to detect secondary particles of an electromagnetic shower. We focus on the use of the multiple pixels on the Photonis MCP in order to find a transverse two-dimensional shower distribution. A spatial resolution of 0.8 mm was obtained with an 8 GeV electron beam. As a result, a method for measuring themore » arrival time resolution for electromagnetic showers is presented, and we show that time resolution better than 40 ps can be achieved.« less

The numerical evaluation of maximum-likelihood estimates of the parameters for a mixture of normal distributions from partially identified samples

NASA Technical Reports Server (NTRS)

Walker, H. F.

1976-01-01

Likelihood equations determined by the two types of samples which are necessary conditions for a maximum-likelihood estimate were considered. These equations suggest certain successive approximations iterative procedures for obtaining maximum likelihood estimates. The procedures, which are generalized steepest ascent (deflected gradient) procedures, contain those of Hosmer as a special case.

12 CFR 741.204 - Maximum public unit and nonmember accounts, and low-income designation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... low-income designation. 741.204 Section 741.204 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION... Unions § 741.204 Maximum public unit and nonmember accounts, and low-income designation. Any credit union...) Obtain a low-income designation in order to accept nonmember accounts, other than from public units or...

Direct comparison of phase-sensitive vibrational sum frequency generation with maximum entropy method: case study of water.

PubMed

de Beer, Alex G F; Samson, Jean-Sebastièn; Hua, Wei; Huang, Zishuai; Chen, Xiangke; Allen, Heather C; Roke, Sylvie

2011-12-14

We present a direct comparison of phase sensitive sum-frequency generation experiments with phase reconstruction obtained by the maximum entropy method. We show that both methods lead to the same complex spectrum. Furthermore, we discuss the strengths and weaknesses of each of these methods, analyzing possible sources of experimental and analytical errors. A simulation program for maximum entropy phase reconstruction is available at: http://lbp.epfl.ch/. © 2011 American Institute of Physics

The use of the Hurst exponent to investigate the global maximum of the Warsaw Stock Exchange WIG20 index

NASA Astrophysics Data System (ADS)

Domino, Krzysztof

2012-01-01

The WIG20 index-the index of the 20 biggest companies traded on the Warsaw Stock Exchange-reached the global maximum on 29th October 2007. I have used the local DFA (Detrended Functional Analysis) to obtain the Hurst exponent (diffusion exponent) and investigate the signature of anti-correlation of share price evolution around the maximum. The analysis was applied to the share price evolution for variable DFA parameters. For many values of parameters, the evidence of anti-correlation near the WIG20 maximum was pointed out.

Direct tests of micro channel plates as the active element of a new shower maximum detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronzhin, A.; Los, S.; Ramberg, E.

2015-05-22

We continue the study of micro channel plates (MCP) as the active element of a shower maximum (SM) detector. We present below test beam results obtained with MCPs detecting directly secondary particles of an electromagnetic shower. The MCP efficiency to shower particles is close to 100%. Furthermore, the time resolution obtained for this new type of the SM detector is at the level of 40 ps.

A maximum power point tracking algorithm for photovoltaic applications

NASA Astrophysics Data System (ADS)

Nelatury, Sudarshan R.; Gray, Robert

2013-05-01

The voltage and current characteristic of a photovoltaic (PV) cell is highly nonlinear and operating a PV cell for maximum power transfer has been a challenge for a long time. Several techniques have been proposed to estimate and track the maximum power point (MPP) in order to improve the overall efficiency of a PV panel. A strategic use of the mean value theorem permits obtaining an analytical expression for a point that lies in a close neighborhood of the true MPP. But hitherto, an exact solution in closed form for the MPP is not published. This problem can be formulated analytically as a constrained optimization, which can be solved using the Lagrange method. This method results in a system of simultaneous nonlinear equations. Solving them directly is quite difficult. However, we can employ a recursive algorithm to yield a reasonably good solution. In graphical terms, suppose the voltage current characteristic and the constant power contours are plotted on the same voltage current plane, the point of tangency between the device characteristic and the constant power contours is the sought for MPP. It is subject to change with the incident irradiation and temperature and hence the algorithm that attempts to maintain the MPP should be adaptive in nature and is supposed to have fast convergence and the least misadjustment. There are two parts in its implementation. First, one needs to estimate the MPP. The second task is to have a DC-DC converter to match the given load to the MPP thus obtained. Availability of power electronics circuits made it possible to design efficient converters. In this paper although we do not show the results from a real circuit, we use MATLAB to obtain the MPP and a buck-boost converter to match the load. Under varying conditions of load resistance and irradiance we demonstrate MPP tracking in case of a commercially available solar panel MSX-60. The power electronics circuit is simulated by PSIM software.

Finding Maximum Cliques on the D-Wave Quantum Annealer

DOE PAGES

Chapuis, Guillaume; Djidjev, Hristo; Hahn, Georg; ...

2018-05-03

This work assesses the performance of the D-Wave 2X (DW) quantum annealer for finding a maximum clique in a graph, one of the most fundamental and important NP-hard problems. Because the size of the largest graphs DW can directly solve is quite small (usually around 45 vertices), we also consider decomposition algorithms intended for larger graphs and analyze their performance. For smaller graphs that fit DW, we provide formulations of the maximum clique problem as a quadratic unconstrained binary optimization (QUBO) problem, which is one of the two input types (together with the Ising model) acceptable by the machine, andmore » compare several quantum implementations to current classical algorithms such as simulated annealing, Gurobi, and third-party clique finding heuristics. We further estimate the contributions of the quantum phase of the quantum annealer and the classical post-processing phase typically used to enhance each solution returned by DW. We demonstrate that on random graphs that fit DW, no quantum speedup can be observed compared with the classical algorithms. On the other hand, for instances specifically designed to fit well the DW qubit interconnection network, we observe substantial speed-ups in computing time over classical approaches.« less

Finding Maximum Cliques on the D-Wave Quantum Annealer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapuis, Guillaume; Djidjev, Hristo; Hahn, Georg

This work assesses the performance of the D-Wave 2X (DW) quantum annealer for finding a maximum clique in a graph, one of the most fundamental and important NP-hard problems. Because the size of the largest graphs DW can directly solve is quite small (usually around 45 vertices), we also consider decomposition algorithms intended for larger graphs and analyze their performance. For smaller graphs that fit DW, we provide formulations of the maximum clique problem as a quadratic unconstrained binary optimization (QUBO) problem, which is one of the two input types (together with the Ising model) acceptable by the machine, andmore » compare several quantum implementations to current classical algorithms such as simulated annealing, Gurobi, and third-party clique finding heuristics. We further estimate the contributions of the quantum phase of the quantum annealer and the classical post-processing phase typically used to enhance each solution returned by DW. We demonstrate that on random graphs that fit DW, no quantum speedup can be observed compared with the classical algorithms. On the other hand, for instances specifically designed to fit well the DW qubit interconnection network, we observe substantial speed-ups in computing time over classical approaches.« less

High performance diamond-like carbon layers obtained by pulsed laser deposition for conductive electrode applications

NASA Astrophysics Data System (ADS)

Stock, F.; Antoni, F.; Le Normand, F.; Muller, D.; Abdesselam, M.; Boubiche, N.; Komissarov, I.

2017-09-01

For the future, one of the biggest challenge faced to the technologies of flat panel display and various optoelectronic and photovoltaic devices is to find an alternative to the use of transparent conducting oxides like ITO. In this new approach, the objective is to grow high conductive thin-layer graphene (TLG) on the top of diamond-like carbon (DLC) layers presenting high performance. DLC prepared by pulsed laser deposition (PLD) have attracted special interest due to a unique combination of their properties, close to those of monocrystalline diamond, like its transparency, hardness and chemical inertia, very low roughness, hydrogen-free and thus high thermal stability up to 1000 K. In our future work, we plane to explore the synthesis of conductive TLG on top of insulating DLC thin films. The feasibility and obtained performances of the multi-layered structure will be explored in great details in the short future to develop an alternative to ITO with comparable performance (conductivity of transparency). To select the best DLC candidate for this purpose, we focus this work on the physicochemical properties of the DLC thin films deposited by PLD from a pure graphite target at two wavelengths (193 and 248 nm) at various laser fluences. A surface graphenization process, as well as the required efficiency of the complete structure (TLG/DLC) will clearly be related to the DLC properties, especially to the initial sp3/sp2 hybridization ratio. Thus, an exhaustive description of the physicochemical properties of the DLC layers is a fundamental step in the research of comparable performance to ITO.

Extracting volatility signal using maximum a posteriori estimation

NASA Astrophysics Data System (ADS)

Neto, David

2016-11-01

This paper outlines a methodology to estimate a denoised volatility signal for foreign exchange rates using a hidden Markov model (HMM). For this purpose a maximum a posteriori (MAP) estimation is performed. A double exponential prior is used for the state variable (the log-volatility) in order to allow sharp jumps in realizations and then log-returns marginal distributions with heavy tails. We consider two routes to choose the regularization and we compare our MAP estimate to realized volatility measure for three exchange rates.

The radial distribution of cosmic rays in the heliosphere at solar maximum

NASA Astrophysics Data System (ADS)

McDonald, F. B.; Fujii, Z.; Heikkila, B.; Lal, N.

2003-08-01

To obtain a more detailed profile of the radial distribution of galactic (GCRs) and anomalous (ACRs) cosmic rays, a unique time in the 11-year solar activity cycle has been selected - that of solar maximum. At this time of minimum cosmic ray intensity a simple, straight-forward normalization technique has been found that allows the cosmic ray data from IMP 8, Pioneer 10 (P-10) and Voyagers 1 and 2 (V1, V2) to be combined for the solar maxima of cycles 21, 22 and 23. This combined distribution reveals a functional form of the radial gradient that varies as G 0/r with G 0 being constant and relatively small in the inner heliosphere. After a transition region between ˜10 and 20 AU, G 0 increases to a much larger value that remains constant between ˜25 and 82 AU. This implies that at solar maximum the changes that produce the 11-year modulation cycle are mainly occurring in the outer heliosphere between ˜15 AU and the termination shock. These observations are not inconsistent with the concept that Global Merged Interaction. regions (GMIRs) are the principal agent of modulation between solar minimum and solar maximum. There does not appear to be a significant change in the amount of heliosheath modulation occurring between the 1997 solar minimum and the cycle 23 solar maximum.

14 CFR 27.1527 - Maximum operating altitude.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as limited...

24 CFR 232.903 - Maximum mortgage limitations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Maximum mortgage limitations. 232... ASSISTED LIVING FACILITIES Insurance of Mortgages Covering Existing Projects § 232.903 Maximum mortgage limitations. Notwithstanding the maximum mortgage limitations set forth in § 232.30, a mortgage within the...

14 CFR 29.1527 - Maximum operating altitude.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

Application of maximum likelihood methods to laser Thomson scattering measurements of low density plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Washeleski, Robert L.; Meyer, Edmond J. IV; King, Lyon B.

2013-10-15

Laser Thomson scattering (LTS) is an established plasma diagnostic technique that has seen recent application to low density plasmas. It is difficult to perform LTS measurements when the scattered signal is weak as a result of low electron number density, poor optical access to the plasma, or both. Photon counting methods are often implemented in order to perform measurements in these low signal conditions. However, photon counting measurements performed with photo-multiplier tubes are time consuming and multi-photon arrivals are incorrectly recorded. In order to overcome these shortcomings a new data analysis method based on maximum likelihood estimation was developed. Themore » key feature of this new data processing method is the inclusion of non-arrival events in determining the scattered Thomson signal. Maximum likelihood estimation and its application to Thomson scattering at low signal levels is presented and application of the new processing method to LTS measurements performed in the plume of a 2-kW Hall-effect thruster is discussed.« less

Application of maximum likelihood methods to laser Thomson scattering measurements of low density plasmas.

PubMed

Washeleski, Robert L; Meyer, Edmond J; King, Lyon B

2013-10-01

Laser Thomson scattering (LTS) is an established plasma diagnostic technique that has seen recent application to low density plasmas. It is difficult to perform LTS measurements when the scattered signal is weak as a result of low electron number density, poor optical access to the plasma, or both. Photon counting methods are often implemented in order to perform measurements in these low signal conditions. However, photon counting measurements performed with photo-multiplier tubes are time consuming and multi-photon arrivals are incorrectly recorded. In order to overcome these shortcomings a new data analysis method based on maximum likelihood estimation was developed. The key feature of this new data processing method is the inclusion of non-arrival events in determining the scattered Thomson signal. Maximum likelihood estimation and its application to Thomson scattering at low signal levels is presented and application of the new processing method to LTS measurements performed in the plume of a 2-kW Hall-effect thruster is discussed.

Operational forecasting of daily temperatures in the Valencia Region. Part I: maximum temperatures in summer.

NASA Astrophysics Data System (ADS)

Gómez, I.; Estrela, M.

2009-09-01

Extreme temperature events have a great impact on human society. Knowledge of summer maximum temperatures is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, summer maximum daily temperatures are considered a parameter of interest and concern since persistent heat-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict heat-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that high temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily maximum temperatures during summer over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the summer forecast period of 1 June - 30 September, 2007. The results obtained are encouraging and indicate a good agreement between the observed and simulated maximum temperatures. Moreover, the model captures quite well the temperatures in the extreme heat episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educación y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulación de las olas de calor e invasiones de frío y su regionalización en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia, Spain).

A general formula for computing maximum proportion correct scores in various psychophysical paradigms with arbitrary probability distributions of stimulus observations.

PubMed

Dai, Huanping; Micheyl, Christophe

2015-05-01

Proportion correct (Pc) is a fundamental measure of task performance in psychophysics. The maximum Pc score that can be achieved by an optimal (maximum-likelihood) observer in a given task is of both theoretical and practical importance, because it sets an upper limit on human performance. Within the framework of signal detection theory, analytical solutions for computing the maximum Pc score have been established for several common experimental paradigms under the assumption of Gaussian additive internal noise. However, as the scope of applications of psychophysical signal detection theory expands, the need is growing for psychophysicists to compute maximum Pc scores for situations involving non-Gaussian (internal or stimulus-induced) noise. In this article, we provide a general formula for computing the maximum Pc in various psychophysical experimental paradigms for arbitrary probability distributions of sensory activity. Moreover, easy-to-use MATLAB code implementing the formula is provided. Practical applications of the formula are illustrated, and its accuracy is evaluated, for two paradigms and two types of probability distributions (uniform and Gaussian). The results demonstrate that Pc scores computed using the formula remain accurate even for continuous probability distributions, as long as the conversion from continuous probability density functions to discrete probability mass functions is supported by a sufficiently high sampling resolution. We hope that the exposition in this article, and the freely available MATLAB code, facilitates calculations of maximum performance for a wider range of experimental situations, as well as explorations of the impact of different assumptions concerning internal-noise distributions on maximum performance in psychophysical experiments.

31 CFR 149.3 - Maximum obligation limitation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Maximum obligation limitation. 149.3 Section 149.3 Money and Finance: Treasury Regulations Relating to Money and Finance MONETARY OFFICES, DEPARTMENT OF THE TREASURY CALCULATION OF MAXIMUM OBLIGATION LIMITATION § 149.3 Maximum obligation limitation...

40 CFR 35.175 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.175 Section 35.175 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...)) § 35.175 Maximum federal share. The Regional Administrator may provide a maximum of 75 percent of the...

10 CFR 600.20 - Maximum DOE obligation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Maximum DOE obligation. 600.20 Section 600.20 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS FINANCIAL ASSISTANCE RULES General § 600.20 Maximum DOE obligation. (a) The maximum DOE obligation to the recipient is— (1) For monetary awards, the...

5 CFR 582.402 - Maximum garnishment limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Maximum garnishment limitations. 582.402... Maximum garnishment limitations. Pursuant to section 1673(a)(1) of title 15 of the United States Code (the... Federal Regulations, part 870, the following limitations are applicable: (a) Unless a lower maximum...

5 CFR 581.402 - Maximum garnishment limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Maximum garnishment limitations. 581.402... § 581.402 Maximum garnishment limitations. (a) Except as provided in paragraph (b) of this section... Protection Act, as amended), unless a lower maximum garnishment limitation is provided by applicable State or...

40 CFR 35.195 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.195 Section 35.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... 1443(b)) § 35.195 Maximum federal share. The Regional Administrator may provide a maximum of 75 percent...

Bayesian image reconstruction for improving detection performance of muon tomography.

PubMed

Wang, Guobao; Schultz, Larry J; Qi, Jinyi

2009-05-01

Muon tomography is a novel technology that is being developed for detecting high-Z materials in vehicles or cargo containers. Maximum likelihood methods have been developed for reconstructing the scattering density image from muon measurements. However, the instability of maximum likelihood estimation often results in noisy images and low detectability of high-Z targets. In this paper, we propose using regularization to improve the image quality of muon tomography. We formulate the muon reconstruction problem in a Bayesian framework by introducing a prior distribution on scattering density images. An iterative shrinkage algorithm is derived to maximize the log posterior distribution. At each iteration, the algorithm obtains the maximum a posteriori update by shrinking an unregularized maximum likelihood update. Inverse quadratic shrinkage functions are derived for generalized Laplacian priors and inverse cubic shrinkage functions are derived for generalized Gaussian priors. Receiver operating characteristic studies using simulated data demonstrate that the Bayesian reconstruction can greatly improve the detection performance of muon tomography.

7 CFR 3565.210 - Maximum interest rate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Maximum interest rate. 3565.210 Section 3565.210... AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.210 Maximum interest rate. The interest rate for a guaranteed loan must not exceed the maximum allowable rate specified by the Agency in...

49 CFR 1503.401 - Maximum penalty amounts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Maximum penalty amounts. 1503.401 Section 1503.401... Assessment of Civil Penalties by TSA § 1503.401 Maximum penalty amounts. (a) General. TSA may assess civil.... TSA may adjust the maximum civil penalty amounts in conformity with the Federal Civil Penalties...

34 CFR 682.204 - Maximum loan amounts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Maximum loan amounts. 682.204 Section 682.204 Education..., DEPARTMENT OF EDUCATION FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM General Provisions § 682.204 Maximum... a full academic year, the maximum annual amount that the student may receive may not exceed the...

40 CFR 35.675 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.675 Section... (section 1443(a) and Section 1451) § 35.675 Maximum federal share. (a) The Regional Administrator may... maximum federal share if the Tribe or Intertribal Consortium can demonstrate in writing to the...

Maximum work extraction and implementation costs for nonequilibrium Maxwell's demons.

PubMed

Sandberg, Henrik; Delvenne, Jean-Charles; Newton, Nigel J; Mitter, Sanjoy K

2014-10-01

We determine the maximum amount of work extractable in finite time by a demon performing continuous measurements on a quadratic Hamiltonian system subjected to thermal fluctuations, in terms of the information extracted from the system. The maximum work demon is found to apply a high-gain continuous feedback involving a Kalman-Bucy estimate of the system state and operates in nonequilibrium. A simple and concrete electrical implementation of the feedback protocol is proposed, which allows for analytic expressions of the flows of energy, entropy, and information inside the demon. This let us show that any implementation of the demon must necessarily include an external power source, which we prove both from classical thermodynamics arguments and from a version of Landauer's memory erasure argument extended to nonequilibrium linear systems.

3D flexible alignment using 2D maximum common substructure: dependence of prediction accuracy on target-reference chemical similarity.

PubMed

Kawabata, Takeshi; Nakamura, Haruki

2014-07-28

A protein-bound conformation of a target molecule can be predicted by aligning the target molecule on the reference molecule obtained from the 3D structure of the compound-protein complex. This strategy is called "similarity-based docking". For this purpose, we develop the flexible alignment program fkcombu, which aligns the target molecule based on atomic correspondences with the reference molecule. The correspondences are obtained by the maximum common substructure (MCS) of 2D chemical structures, using our program kcombu. The prediction performance was evaluated using many target-reference pairs of superimposed ligand 3D structures on the same protein in the PDB, with different ranges of chemical similarity. The details of atomic correspondence largely affected the prediction success. We found that topologically constrained disconnected MCS (TD-MCS) with the simple element-based atomic classification provides the best prediction. The crashing potential energy with the receptor protein improved the performance. We also found that the RMSD between the predicted and correct target conformations significantly correlates with the chemical similarities between target-reference molecules. Generally speaking, if the reference and target compounds have more than 70% chemical similarity, then the average RMSD of 3D conformations is <2.0 Å. We compared the performance with a rigid-body molecular alignment program based on volume-overlap scores (ShaEP). Our MCS-based flexible alignment program performed better than the rigid-body alignment program, especially when the target and reference molecules were sufficiently similar.

Applying a Weighted Maximum Likelihood Latent Trait Estimator to the Generalized Partial Credit Model

ERIC Educational Resources Information Center

Penfield, Randall D.; Bergeron, Jennifer M.

2005-01-01

This article applies a weighted maximum likelihood (WML) latent trait estimator to the generalized partial credit model (GPCM). The relevant equations required to obtain the WML estimator using the Newton-Raphson algorithm are presented, and a simulation study is described that compared the properties of the WML estimator to those of the maximum…

40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

Code of Federal Regulations, 2010 CFR

2010-07-01

... vapor pressure of my remediation material? 63.7944 Section 63.7944 Protection of Environment... Pollutants: Site Remediation Performance Tests § 63.7944 How do I determine the maximum HAP vapor pressure of my remediation material? (a) You must determine the maximum HAP vapor pressure of your remediation...

22 CFR 201.67 - Maximum freight charges.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Maximum freight charges. 201.67 Section 201.67... TRANSACTIONS FINANCED BY USAID Price Provisions § 201.67 Maximum freight charges. (a) Ocean freight rates—(1... the United States. (2) Maximum charter rates. (i) USAID will not finance ocean freight under any...

40 CFR 35.635 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.635 Section... (sections 319(h) and 518(f)) § 35.635 Maximum federal share. (a) The Regional Administrator may provide up... be provided from non-federal sources. (b) The Regional Administrator may increase the maximum federal...

40 CFR 35.575 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.575 Section...) § 35.575 Maximum federal share. (a) For Tribes and Intertribal Consortia eligible under § 35.573(a... the maximum federal share to 90 percent if the Regional Administrator determines that the Tribe or...

40 CFR 35.685 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.685 Section... (section 1443(b)) § 35.685 Maximum federal share. (a) The Regional Administrator may provide up to 75 percent of the approved work plan costs. (b) The Regional Administrator may increase the maximum federal...

5 CFR 550.105 - Biweekly maximum earnings limitation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Biweekly maximum earnings limitation. 550... PAY ADMINISTRATION (GENERAL) Premium Pay Maximum Earnings Limitations § 550.105 Biweekly maximum... basic pay and premium pay for any biweekly pay period to exceed the greater of— (1) The maximum biweekly...

5 CFR 550.106 - Annual maximum earnings limitation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Annual maximum earnings limitation. 550... PAY ADMINISTRATION (GENERAL) Premium Pay Maximum Earnings Limitations § 550.106 Annual maximum... and premium pay for the calendar year to exceed the greater of— (1) The maximum annual rate of basic...

Approximated maximum likelihood estimation in multifractal random walks

NASA Astrophysics Data System (ADS)

Løvsletten, O.; Rypdal, M.

2012-04-01

We present an approximated maximum likelihood method for the multifractal random walk processes of [E. Bacry , Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.64.026103 64, 026103 (2001)]. The likelihood is computed using a Laplace approximation and a truncation in the dependency structure for the latent volatility. The procedure is implemented as a package in the r computer language. Its performance is tested on synthetic data and compared to an inference approach based on the generalized method of moments. The method is applied to estimate parameters for various financial stock indices.

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

NASA Astrophysics Data System (ADS)

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

2018-04-01

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

The Maximum Likelihood Estimation of Signature Transformation /MLEST/ algorithm. [for affine transformation of crop inventory data

NASA Technical Reports Server (NTRS)

Thadani, S. G.

1977-01-01

The Maximum Likelihood Estimation of Signature Transformation (MLEST) algorithm is used to obtain maximum likelihood estimates (MLE) of affine transformation. The algorithm has been evaluated for three sets of data: simulated (training and recognition segment pairs), consecutive-day (data gathered from Landsat images), and geographical-extension (large-area crop inventory experiment) data sets. For each set, MLEST signature extension runs were made to determine MLE values and the affine-transformed training segment signatures were used to classify the recognition segments. The classification results were used to estimate wheat proportions at 0 and 1% threshold values.

29 CFR 778.100 - The maximum-hours provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false The maximum-hours provisions. 778.100 Section 778.100 Labor... Requirements Introductory § 778.100 The maximum-hours provisions. Section 7(a) of the Act deals with maximum... specifically exempt from its overtime pay requirements. It prescribes the maximum weekly hours of work...

29 CFR 778.101 - Maximum nonovertime hours.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Maximum nonovertime hours. 778.101 Section 778.101 Labor... Requirements Introductory § 778.101 Maximum nonovertime hours. As a general standard, section 7(a) of the Act provides 40 hours as the maximum number that an employee subject to its provisions may work for an employer...

Performance calculations for 200-1000 MWe MHD/steam power plants

NASA Technical Reports Server (NTRS)

Staiger, P. J.

1981-01-01

The effects of MHD generator length, level of oxygen enrichment, and oxygen production power on the performance of MHD/steam power plants ranging from 200 to 1000 MW in electrical output are investigated. The plants considered use oxygen enriched combustion air preheated to 1100 F. Both plants in which the MHD generator is cooled with low temperature and pressure boiler feedwater and plants in which the generator is cooled with high temperature and pressure boiler feedwater are considered. For plants using low temperature boiler feedwater for generator cooling the maximum thermodynamic efficiency is obtained with shorter generators and a lower level of oxygen enrichment compared to plants using high temperature boiler feedwater for generator cooling. The generator length at which the maximum plant efficiency occurs increases with power plant size for plants with a generator cooled by low temperature feedwater. Also shown is the relationship of the magnet stored energy requirement of the generator length and the power plant performance. Possible cost/performance tradeoffs between magnet cost and plant performance are indicated.

Computing Maximum Cardinality Matchings in Parallel on Bipartite Graphs via Tree-Grafting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azad, Ariful; Buluc, Aydn; Pothen, Alex

It is difficult to obtain high performance when computing matchings on parallel processors because matching algorithms explicitly or implicitly search for paths in the graph, and when these paths become long, there is little concurrency. In spite of this limitation, we present a new algorithm and its shared-memory parallelization that achieves good performance and scalability in computing maximum cardinality matchings in bipartite graphs. This algorithm searches for augmenting paths via specialized breadth-first searches (BFS) from multiple source vertices, hence creating more parallelism than single source algorithms. Algorithms that employ multiple-source searches cannot discard a search tree once no augmenting pathmore » is discovered from the tree, unlike algorithms that rely on single-source searches. We describe a novel tree-grafting method that eliminates most of the redundant edge traversals resulting from this property of multiple-source searches. We also employ the recent direction-optimizing BFS algorithm as a subroutine to discover augmenting paths faster. Our algorithm compares favorably with the current best algorithms in terms of the number of edges traversed, the average augmenting path length, and the number of iterations. Here, we provide a proof of correctness for our algorithm. Our NUMA-aware implementation is scalable to 80 threads of an Intel multiprocessor and to 240 threads on an Intel Knights Corner coprocessor. On average, our parallel algorithm runs an order of magnitude faster than the fastest algorithms available. The performance improvement is more significant on graphs with small matching number.« less

Computing Maximum Cardinality Matchings in Parallel on Bipartite Graphs via Tree-Grafting

DOE PAGES

Azad, Ariful; Buluc, Aydn; Pothen, Alex

2016-03-24

It is difficult to obtain high performance when computing matchings on parallel processors because matching algorithms explicitly or implicitly search for paths in the graph, and when these paths become long, there is little concurrency. In spite of this limitation, we present a new algorithm and its shared-memory parallelization that achieves good performance and scalability in computing maximum cardinality matchings in bipartite graphs. This algorithm searches for augmenting paths via specialized breadth-first searches (BFS) from multiple source vertices, hence creating more parallelism than single source algorithms. Algorithms that employ multiple-source searches cannot discard a search tree once no augmenting pathmore » is discovered from the tree, unlike algorithms that rely on single-source searches. We describe a novel tree-grafting method that eliminates most of the redundant edge traversals resulting from this property of multiple-source searches. We also employ the recent direction-optimizing BFS algorithm as a subroutine to discover augmenting paths faster. Our algorithm compares favorably with the current best algorithms in terms of the number of edges traversed, the average augmenting path length, and the number of iterations. Here, we provide a proof of correctness for our algorithm. Our NUMA-aware implementation is scalable to 80 threads of an Intel multiprocessor and to 240 threads on an Intel Knights Corner coprocessor. On average, our parallel algorithm runs an order of magnitude faster than the fastest algorithms available. The performance improvement is more significant on graphs with small matching number.« less

Superfast maximum-likelihood reconstruction for quantum tomography

NASA Astrophysics Data System (ADS)

Shang, Jiangwei; Zhang, Zhengyun; Ng, Hui Khoon

2017-06-01

Conventional methods for computing maximum-likelihood estimators (MLE) often converge slowly in practical situations, leading to a search for simplifying methods that rely on additional assumptions for their validity. In this work, we provide a fast and reliable algorithm for maximum-likelihood reconstruction that avoids this slow convergence. Our method utilizes the state-of-the-art convex optimization scheme, an accelerated projected-gradient method, that allows one to accommodate the quantum nature of the problem in a different way than in the standard methods. We demonstrate the power of our approach by comparing its performance with other algorithms for n -qubit state tomography. In particular, an eight-qubit situation that purportedly took weeks of computation time in 2005 can now be completed in under a minute for a single set of data, with far higher accuracy than previously possible. This refutes the common claim that MLE reconstruction is slow and reduces the need for alternative methods that often come with difficult-to-verify assumptions. In fact, recent methods assuming Gaussian statistics or relying on compressed sensing ideas are demonstrably inapplicable for the situation under consideration here. Our algorithm can be applied to general optimization problems over the quantum state space; the philosophy of projected gradients can further be utilized for optimization contexts with general constraints.

Maximum group velocity in a one-dimensional model with a sinusoidally varying staggered potential

NASA Astrophysics Data System (ADS)

Nag, Tanay; Sen, Diptiman; Dutta, Amit

2015-06-01

We use Floquet theory to study the maximum value of the stroboscopic group velocity in a one-dimensional tight-binding model subjected to an on-site staggered potential varying sinusoidally in time. The results obtained by numerically diagonalizing the Floquet operator are analyzed using a variety of analytical schemes. In the low-frequency limit we use adiabatic theory, while in the high-frequency limit the Magnus expansion of the Floquet Hamiltonian turns out to be appropriate. When the magnitude of the staggered potential is much greater or much less than the hopping, we use degenerate Floquet perturbation theory; we find that dynamical localization occurs in the former case when the maximum group velocity vanishes. Finally, starting from an "engineered" initial state where the particles (taken to be hard-core bosons) are localized in one part of the chain, we demonstrate that the existence of a maximum stroboscopic group velocity manifests in a light-cone-like spreading of the particles in real space.

Probabilistic description of probable maximum precipitation

NASA Astrophysics Data System (ADS)

Ben Alaya, Mohamed Ali; Zwiers, Francis W.; Zhang, Xuebin

2017-04-01

Probable Maximum Precipitation (PMP) is the key parameter used to estimate probable Maximum Flood (PMF). PMP and PMF are important for dam safety and civil engineering purposes. Even if the current knowledge of storm mechanisms remains insufficient to properly evaluate limiting values of extreme precipitation, PMP estimation methods are still based on deterministic consideration, and give only single values. This study aims to provide a probabilistic description of the PMP based on the commonly used method, the so-called moisture maximization. To this end, a probabilistic bivariate extreme values model is proposed to address the limitations of traditional PMP estimates via moisture maximization namely: (i) the inability to evaluate uncertainty and to provide a range PMP values, (ii) the interpretation that a maximum of a data series as a physical upper limit (iii) and the assumption that a PMP event has maximum moisture availability. Results from simulation outputs of the Canadian Regional Climate Model CanRCM4 over North America reveal the high uncertainties inherent in PMP estimates and the non-validity of the assumption that PMP events have maximum moisture availability. This later assumption leads to overestimation of the PMP by an average of about 15% over North America, which may have serious implications for engineering design.

An investigation of rugby scrimmaging posture and individual maximum pushing force.

PubMed

Wu, Wen-Lan; Chang, Jyh-Jong; Wu, Jia-Hroung; Guo, Lan-Yuen

2007-02-01

Although rugby is a popular contact sport and the isokinetic muscle torque assessment has recently found widespread application in the field of sports medicine, little research has examined the factors associated with the performance of game-specific skills directly by using the isokinetic-type rugby scrimmaging machine. This study is designed to (a) measure and observe the differences in the maximum individual pushing forward force produced by scrimmaging in different body postures (3 body heights x 2 foot positions) with a self-developed rugby scrimmaging machine and (b) observe the variations in hip, knee, and ankle angles at different body postures and explore the relationship between these angle values and the individual maximum pushing force. Ten national rugby players were invited to participate in the examination. The experimental equipment included a self-developed rugby scrimmaging machine and a 3-dimensional motion analysis system. Our results showed that the foot positions (parallel and nonparallel foot positions) do not affect the maximum pushing force; however, the maximum pushing force was significantly lower in posture I (36% body height) than in posture II (38%) and posture III (40%). The maximum forward force in posture III (40% body height) was also slightly greater than for the scrum in posture II (38% body height). In addition, it was determined that hip, knee, and ankle angles under parallel feet positioning are factors that are closely negatively related in terms of affecting maximum pushing force in scrimmaging. In cross-feet postures, there was a positive correlation between individual forward force and hip angle of the rear leg. From our results, we can conclude that if the player stands in an appropriate starting position at the early stage of scrimmaging, it will benefit the forward force production.

Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy.

PubMed

Sengbusch, E; Pérez-Andújar, A; DeLuca, P M; Mackie, T R

2009-02-01

Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment system. The commonly used value for the maximum kinetic energy required for a medical proton accelerator is 250 MeV, but it has not been demonstrated that this energy is indeed necessary to treat all or most patients eligible for proton therapy. This article quantifies the maximum kinetic energy of protons, immediately prior to entry into the patient, necessary to treat a given percentage of patients with rotational proton therapy, and examines the impact of this energy threshold on the cost and feasibility of a compact, gantry-mounted proton accelerator treatment system. One hundred randomized treatment plans from patients treated with IMRT were analyzed. The maximum radiological pathlength from the surface of the patient to the distal edge of the treatment volume was obtained for 180 degrees continuous arc proton therapy and for 180 degrees split arc proton therapy (two 90 degrees arcs) using CT# profiles from the Pinnacle (Philips Medical Systems, Madison, WI) treatment planning system. In each case, the maximum kinetic energy of protons, immediately prior to entry into the patient, that would be necessary to treat the patient was calculated using proton range tables for various media. In addition, Monte Carlo simulations were performed to quantify neutron production in a water phantom representing a patient as a function of the maximum proton kinetic energy achievable by a proton treatment system. Protons with a kinetic energy of 240 MeV, immediately prior to entry into the patient, were needed to treat 100% of patients in this study. However, it was shown that 90% of patients could be treated at 198 MeV, and 95% of patients could be treated at 207 MeV. Decreasing the

Does the prevalence of levator ani muscle avulsion differ when assessed using tomographic ultrasound imaging at rest vs on maximum pelvic floor muscle contraction?

PubMed

van Delft, K; Thakar, R; Sultan, A H; Kluivers, K B

2015-07-01

It has been suggested that transperineal ultrasound images obtained during maximum pelvic floor muscle contraction improve the diagnosis of levator ani muscle (LAM) avulsion by comparison with those obtained at rest. The objective of this study was to establish, using transperineal tomographic ultrasound imaging (TUI), the correlation between LAM avulsion diagnosed at rest and that on contraction. Primiparous women were examined 3 months postpartum by Pelvic Organ Prolapse Quantification (POP-Q) assessment and for LAM avulsion clinically by digital palpation and by transperineal TUI performed at rest and on pelvic floor muscle contraction. LAM avulsion was diagnosed on TUI when the three central slices were abnormal. A comparison was made between LAM avulsion diagnosed at rest and on maximum contraction. Two independent blinded investigators performed the analyses and a third investigator resolved discrepancies. One hundred and ninety primiparae were analyzed providing 380 results for comparison, as right and left LAM were analyzed independently. LAM avulsion was found in 36 (9.5%) images obtained at rest and in 35 (9.2%) on contraction, revealing moderate correlation between the two (ICC, 0.58 (95% CI, 0.51-0.64)). Twenty-two cases of LAM avulsion were identified both at rest and on contraction. One woman had LAM avulsion on palpation, which was seen on TUI as LAM avulsion on contraction, but not at rest. More cases of anterior and posterior compartment prolapse were found in women with LAM avulsion diagnosed on contraction only compared to LAM avulsion observed at rest only (POP-Q assessment point Ba, -1.8 vs -2.5 (P = 0.075) and point Bp, -2.5 vs -2.8 (P = 0.072)). Findings on transperineal TUI performed in women at rest and on contraction correlate reasonably well. However, given the trend towards an association with signs of pelvic floor dysfunction, diagnosis of LAM avulsion on contraction seems to be more reliable. Consistency in technique and

7 CFR 1778.11 - Maximum grants.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 12 2010-01-01 2010-01-01 false Maximum grants. 1778.11 Section 1778.11 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE (CONTINUED) EMERGENCY AND IMMINENT COMMUNITY WATER ASSISTANCE GRANTS § 1778.11 Maximum grants. (a) Grants not...

24 CFR 200.15 - Maximum mortgage.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Maximum mortgage. 200.15 Section 200.15 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... Eligibility Requirements for Existing Projects Eligible Mortgage § 200.15 Maximum mortgage. Mortgages must not...

7 CFR 993.602 - Maximum tolerances.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Maximum tolerances. 993.602 Section 993.602 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... CALIFORNIA Grade Regulations § 993.602 Maximum tolerances. In lieu of the provision prescribed in I C of...

14 CFR 65.47 - Maximum hours.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Maximum hours. 65.47 Section 65.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators § 65.47 Maximum hours...

Performance analysis of InGaAs/GaAsP heterojunction double gate tunnel field effect transistor

NASA Astrophysics Data System (ADS)

Ahish, S.; Sharma, Dheeraj; Vasantha, M. H.; Kumar, Y. B. N.

2017-03-01

In this paper, analog/RF performance of InGaAs/GaAsP heterojunction double gate tunnel field effect transistor (HJTFET) has been explored. A highly doped n+ layer is placed at the Source-Channel junction in order to improve the horizontal electric field component and thus, improve the realiability of the device. The analog performance of the device is analysed by extracting current-voltage characteristics, transcondutance (gm), gate-to-drain capacitance (Cgd) and gate-to-source capacitance (Cgs). Further, RF performance of the device is evaluated by obtaining cut-off frequency (fT) and Gain Bandwidth (GBW) product. ION /IOFF ratio equal to ≈ 109, subthreshold slope of 27 mV/dec, maximum fT of 2.1 THz and maximum GBW of 484 GHz were achieved. Also, the impact of temperature variation on the linearity performance of the device has been investigated. Furthermore, the circuit level performance of the device is performed by implementing a Common Source (CS) amplifier; maximum gain of 31.11 dB and 3-dB cut-off frequency equal to 91.2 GHz were achieved for load resistance (RL) = 17.5 KΩ.

Renal Cell Carcinoma: Comparison of RENAL Nephrometry and PADUA Scores with Maximum Tumor Diameter for Prediction of Local Recurrence after Thermal Ablation.

PubMed

Maxwell, Aaron W P; Baird, Grayson L; Iannuccilli, Jason D; Mayo-Smith, William W; Dupuy, Damian E

2017-05-01

Purpose To evaluate the performance of the radius, exophytic or endophytic, nearness to collecting system or sinus, anterior or posterior, and location relative to polar lines (RENAL) nephrometry and preoperative aspects and dimensions used for anatomic classification (PADUA) scoring systems and other tumor biometrics for prediction of local tumor recurrence in patients with renal cell carcinoma after thermal ablation. Materials and Methods This HIPAA-compliant study was performed with a waiver of informed consent after institutional review board approval was obtained. A retrospective evaluation of 207 consecutive patients (131 men, 76 women; mean age, 71.9 years ± 10.9) with 217 biopsy-proven renal cell carcinoma tumors treated with thermal ablation was conducted. Serial postablation computed tomography (CT) or magnetic resonance (MR) imaging was used to evaluate for local tumor recurrence. For each tumor, RENAL nephrometry and PADUA scores were calculated by using imaging-derived tumor morphologic data. Several additional tumor biometrics and combinations thereof were also measured, including maximum tumor diameter. The Harrell C index and hazard regression techniques were used to quantify associations with local tumor recurrence. Results The RENAL (hazard ratio, 1.43; P = .003) and PADUA (hazard ratio, 1.80; P < .0001) scores were found to be significantly associated with recurrence when regression techniques were used but demonstrated only poor to fair discrimination according to Harrell C index results (C, 0.68 and 0.75, respectively). Maximum tumor diameter showed the highest discriminatory strength of any individual variable evaluated (C, 0.81) and was also significantly predictive when regression techniques were used (hazard ratio, 2.98; P < .0001). For every 1-cm increase in diameter, the estimated rate of recurrence risk increased by 198%. Conclusion Maximum tumor diameter demonstrates superior performance relative to existing tumor scoring systems and

Exact computation of the maximum-entropy potential of spiking neural-network models.

PubMed

Cofré, R; Cessac, B

2014-05-01

Understanding how stimuli and synaptic connectivity influence the statistics of spike patterns in neural networks is a central question in computational neuroscience. The maximum-entropy approach has been successfully used to characterize the statistical response of simultaneously recorded spiking neurons responding to stimuli. However, in spite of good performance in terms of prediction, the fitting parameters do not explain the underlying mechanistic causes of the observed correlations. On the other hand, mathematical models of spiking neurons (neuromimetic models) provide a probabilistic mapping between the stimulus, network architecture, and spike patterns in terms of conditional probabilities. In this paper we build an exact analytical mapping between neuromimetic and maximum-entropy models.

40 CFR 141.66 - Maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum contaminant levels for... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.66 Maximum contaminant levels for radionuclides. (a) [Reserved] (b) MCL for combined radium-226 and -228. The maximum...

40 CFR 141.66 - Maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum contaminant levels for... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.66 Maximum contaminant levels for radionuclides. (a) [Reserved] (b) MCL for combined radium-226 and -228. The maximum...

40 CFR 141.66 - Maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum contaminant levels for... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.66 Maximum contaminant levels for radionuclides. (a) [Reserved] (b) MCL for combined radium-226 and -228. The maximum...

40 CFR 141.66 - Maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Maximum contaminant levels for... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.66 Maximum contaminant levels for radionuclides. (a) [Reserved] (b) MCL for combined radium-226 and -228. The maximum...

13 CFR 130.440 - Maximum grant.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Maximum grant. 130.440 Section 130.440 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS DEVELOPMENT CENTERS § 130.440 Maximum grant. No recipient shall receive an SBDC grant exceeding the greater of the minimum...

13 CFR 130.440 - Maximum grant.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum grant. 130.440 Section 130.440 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS DEVELOPMENT CENTERS § 130.440 Maximum grant. No recipient shall receive an SBDC grant exceeding the greater of the minimum...

The in-flight performance of the Solar Maximum Mission Electrical Power System

NASA Technical Reports Server (NTRS)

Broderick, R. J.

1981-01-01

Circuitry, power handling, and operational characteristics and anomalies of the Electrical Power System (EPS) of the Solar Maximum Mission are discussed. The EPS is designed as a standard unit to be a candidate for use on future space missions. Blown, improperly derated fuses in the Attitude Control System and the Signal Conditioning Assembly have led to switching to magnetrons for solar angle, with a loss of accuracy, and a loss of one-half of telemetry data, respectively. In addition, reasons for an 11-14% degradation of solar array output are uncertain due to the loss of precise attitude control. Current surges to peak at 76.5 A (down from 94.5 A) at sunrise, stays for four to five minutes, then resumes nominal output for the remainder of the 61-68 daytime period. Eclipse varies between 28 and 35 minutes, with corresponding depth of discharge of 14%. The batteries charge at 20 A, and although an overcharge mode has been continuously sensed, operation has been normal and temperature sensors have not indicated overcharge; cell failure has also not been sensed. The system has a two year design life and a desired life of four years.

Preliminary Results of an Altitude-Wind-Tunnel Investigation of an Axial-Flow Gas Turbine-Propeller Engine. 4; Compressor and Turbine Performance Characteristics

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Saari, Martin J.

1948-01-01

As part of an investigation of the performance and operational characteristics of the axial-flow gas turbine-propeller engine, conducted in the Cleveland altitude wind tunnel, the performance characteristics of the compressor and the turbine were obtained. The data presented were obtained at a compressor-inlet ram-pressure ratio of 1.00 for altitudes from 5000 to 35,000 feet, engine speeds from 8000 to 13,000 rpm, and turbine-inlet temperatures from 1400 to 2100 R. The highest compressor pressure ratio obtained was 6.15 at a corrected air flow of 23.7 pounds per second and a corrected turbine-inlet temperature of 2475 R. Peak adiabatic compressor efficiencies of about 77 percent were obtained near the value of corrected air flow corresponding to a corrected engine speed of 13,000 rpm. This maximum efficiency may be somewhat low, however, because of dirt accumulations on the compressor blades. A maximum adiabatic turbine efficiency of 81.5 percent was obtained at rated engine speed for all altitudes and turbine-inlet temperatures investigated.

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) Notwithstanding any provision herein, the loading of cargo, draft and speed of a vessel in transit shall be...

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) Notwithstanding any provision herein, the loading of cargo, draft and speed of a vessel in transit shall be...

34 CFR 674.12 - Loan maximums.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., DEPARTMENT OF EDUCATION FEDERAL PERKINS LOAN PROGRAM General Provisions § 674.12 Loan maximums. (a) The maximum annual amount of Federal Perkins Loans and NDSLs an eligible student may borrow is— (1) $5,500 for... professional student. (b) The aggregate unpaid principal amount of all Federal Perkins Loans and NDSLs received...

40 CFR 420.134 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... Source Performance Standards (NSPS) Pollutant Maximum daily 1 Maximum monthly avg. 1 TSS 0.00998 0.00465... operations. Subpart M—New Source Performance Standards (NSPS) Pollutant Maximum daily 1 Maximum monthly avg...

40 CFR 420.134 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... Source Performance Standards (NSPS) Pollutant Maximum daily 1 Maximum monthly avg. 1 TSS 0.00998 0.00465... operations. Subpart M—New Source Performance Standards (NSPS) Pollutant Maximum daily 1 Maximum monthly avg...

Antihyperlipidemic Effect of Different Fractions Obtained from Teucrium polium Hydroalcoholic Extract in Rats.

PubMed

Safaeian, Leila; Ghanadian, Mustafa; Shafiee-Moghadam, Zahra

2018-01-01

This study was aimed to screen the antihyperlipidemic effect of different fractions of Teucrium polium to obtain the most efficient herbal fraction for isolation of bioactive constituents responsible for hypolipidemic activity. Chloroform, butanol, and aqueous fractions were obtained from hydroalcoholic extract of T. polium aerial parts using partitioning process. To induce hyperlipidemia, dexamethasone (Dex) was injected 10 mg/kg/day (s.c.) for 8 days. In the test groups, animals received 50, 100 and 150 mg/kg of T. polium hydroalcoholic extract and different fractions orally simultaneously with Dex. Serum lipid profile and hepatic marker enzymes were evaluated using biochemical kits. All treatments, especially chloroform and aqueous fractions, reversed serum lipid markers in hyperlipidemic rats. Maximum reduction in triglyceride (60.2%, P < 0.001) and maximum elevation in high-density lipoprotein (HDL) (35.0%, P < 0.01) was observed for chloroform fraction. Maximum cholesterol-lowering effect (29.0%, P < 0.001) and maximum reduction in low-density lipoprotein were found for hydroalcoholic extract (72.9%, P < 0.001). Aqueous fraction improved all lipid markers at the highest dose. Butanol fraction decreased triglyceride at the lowest dose (43.9%, P < 0.001) and increased HDL (33%, P < 0.05) at the highest dose. There was a significant increase in alanine aminotransferase and aspartate aminotransferase levels in all tested groups compared to normal group ( P < 0.001). This study showed strong antihyperlipidemic effect of various fractions derived from hydroalcoholic extract of T. polium . Chloroform and aqueous fractions may be worthy candidates for isolation of bioactive hypolipidemic constituents. However, possible hepatotoxicity should be considered for clinical application.

On the maximum principle for complete second-order elliptic operators in general domains

NASA Astrophysics Data System (ADS)

Vitolo, Antonio

This paper is concerned with the maximum principle for second-order linear elliptic equations in a wide generality. By means of a geometric condition previously stressed by Berestycki-Nirenberg-Varadhan, Cabré was very able to improve the classical ABP estimate obtaining the maximum principle also in unbounded domains, such as infinite strips and open connected cones with closure different from the whole space. Now we introduce a new geometric condition that extends the result to a more general class of domains including the complements of hypersurfaces, as for instance the cut plane. The methods developed here allow us to deal with complete second-order equations, where the admissible first-order term, forced to be zero in a preceding result with Cafagna, depends on the geometry of the domain.

Investigation of Performance of Axial-Flow Compressor of XT-46 Turbine-Propeller Engine. II - Performance of Revised Compressor at Design Equivalent Speed. II; Performance of Revised Compressor at Design Equivalent Speed

NASA Technical Reports Server (NTRS)

Creagh, John W. R.

1950-01-01

The compressor from the XT-46 turbine-propeller engine was revised by removing the last two rows of stator blades and by eliminating the interstage leakage paths described in a previous report. With the revised compressor, the flow choking point shifted upstream into the last rotor-blade row but the maximum weight flow was not increased over that of the original compressor. The flow range of the revised compressor was reduced to about two-thirds that obtained with the original compressor. The later stages of the compressor did not produce the design static-pressure increase probably because of excessive boundary-layer build-up in this region. Measurements obtained in the ninth-stage stator showed that the performance up to this station was promising but that the last three stages of the compressor were limiting the useful operating range of the preceding stages. Some modifications in flow-passage geometry and blade settings are believed to be necessary, however, before any major improvements in over-all compressor performance can be obtained.

49 CFR 107.329 - Maximum penalties.

Code of Federal Regulations, 2014 CFR

2014-10-01

... violation, except the maximum civil penalty is $175,000 if the violation results in death, serious illness... civil penalty is $175,000 if the violation results in death, serious illness or severe injury to any... 49 Transportation 2 2014-10-01 2014-10-01 false Maximum penalties. 107.329 Section 107.329...

49 CFR 107.329 - Maximum penalties.

Code of Federal Regulations, 2013 CFR

2013-10-01

... violation, except the maximum civil penalty is $175,000 if the violation results in death, serious illness... civil penalty is $175,000 if the violation results in death, serious illness or severe injury to any... 49 Transportation 2 2013-10-01 2013-10-01 false Maximum penalties. 107.329 Section 107.329...

A 3D approximate maximum likelihood localization solver

DOE Office of Scientific and Technical Information (OSTI.GOV)

2016-09-23

A robust three-dimensional solver was needed to accurately and efficiently estimate the time sequence of locations of fish tagged with acoustic transmitters and vocalizing marine mammals to describe in sufficient detail the information needed to assess the function of dam-passage design alternatives and support Marine Renewable Energy. An approximate maximum likelihood solver was developed using measurements of time difference of arrival from all hydrophones in receiving arrays on which a transmission was detected. Field experiments demonstrated that the developed solver performed significantly better in tracking efficiency and accuracy than other solvers described in the literature.

The maximum entropy method of moments and Bayesian probability theory

NASA Astrophysics Data System (ADS)

Bretthorst, G. Larry

2013-08-01

The problem of density estimation occurs in many disciplines. For example, in MRI it is often necessary to classify the types of tissues in an image. To perform this classification one must first identify the characteristics of the tissues to be classified. These characteristics might be the intensity of a T1 weighted image and in MRI many other types of characteristic weightings (classifiers) may be generated. In a given tissue type there is no single intensity that characterizes the tissue, rather there is a distribution of intensities. Often this distributions can be characterized by a Gaussian, but just as often it is much more complicated. Either way, estimating the distribution of intensities is an inference problem. In the case of a Gaussian distribution, one must estimate the mean and standard deviation. However, in the Non-Gaussian case the shape of the density function itself must be inferred. Three common techniques for estimating density functions are binned histograms [1, 2], kernel density estimation [3, 4], and the maximum entropy method of moments [5, 6]. In the introduction, the maximum entropy method of moments will be reviewed. Some of its problems and conditions under which it fails will be discussed. Then in later sections, the functional form of the maximum entropy method of moments probability distribution will be incorporated into Bayesian probability theory. It will be shown that Bayesian probability theory solves all of the problems with the maximum entropy method of moments. One gets posterior probabilities for the Lagrange multipliers, and, finally, one can put error bars on the resulting estimated density function.

Description and performance analysis of a generalized optimal algorithm for aerobraking guidance

NASA Technical Reports Server (NTRS)

Evans, Steven W.; Dukeman, Greg A.

1993-01-01

A practical real-time guidance algorithm has been developed for aerobraking vehicles which nearly minimizes the maximum heating rate, the maximum structural loads, and the post-aeropass delta V requirement for orbit insertion. The algorithm is general and reusable in the sense that a minimum of assumptions are made, thus greatly reducing the number of parameters that must be determined prior to a given mission. A particularly interesting feature is that in-plane guidance performance is tuned by adjusting one mission-dependent, the bank margin; similarly, the out-of-plane guidance performance is tuned by adjusting a plane controller time constant. Other features of the algorithm are simplicity, efficiency and ease of use. The trimmed vehicle with bank angle modulation as the method of trajectory control. Performance of this guidance algorithm is examined by its use in an aerobraking testbed program. The performance inquiry extends to a wide range of entry speeds covering a number of potential mission applications. Favorable results have been obtained with a minimum of development effort, and directions for improvement of performance are indicated.

Accuracy of maximum likelihood estimates of a two-state model in single-molecule FRET

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopich, Irina V.

2015-01-21

Photon sequences from single-molecule Förster resonance energy transfer (FRET) experiments can be analyzed using a maximum likelihood method. Parameters of the underlying kinetic model (FRET efficiencies of the states and transition rates between conformational states) are obtained by maximizing the appropriate likelihood function. In addition, the errors (uncertainties) of the extracted parameters can be obtained from the curvature of the likelihood function at the maximum. We study the standard deviations of the parameters of a two-state model obtained from photon sequences with recorded colors and arrival times. The standard deviations can be obtained analytically in a special case when themore » FRET efficiencies of the states are 0 and 1 and in the limiting cases of fast and slow conformational dynamics. These results are compared with the results of numerical simulations. The accuracy and, therefore, the ability to predict model parameters depend on how fast the transition rates are compared to the photon count rate. In the limit of slow transitions, the key parameters that determine the accuracy are the number of transitions between the states and the number of independent photon sequences. In the fast transition limit, the accuracy is determined by the small fraction of photons that are correlated with their neighbors. The relative standard deviation of the relaxation rate has a “chevron” shape as a function of the transition rate in the log-log scale. The location of the minimum of this function dramatically depends on how well the FRET efficiencies of the states are separated.« less

Accuracy of maximum likelihood estimates of a two-state model in single-molecule FRET

PubMed Central

Gopich, Irina V.

2015-01-01

Photon sequences from single-molecule Förster resonance energy transfer (FRET) experiments can be analyzed using a maximum likelihood method. Parameters of the underlying kinetic model (FRET efficiencies of the states and transition rates between conformational states) are obtained by maximizing the appropriate likelihood function. In addition, the errors (uncertainties) of the extracted parameters can be obtained from the curvature of the likelihood function at the maximum. We study the standard deviations of the parameters of a two-state model obtained from photon sequences with recorded colors and arrival times. The standard deviations can be obtained analytically in a special case when the FRET efficiencies of the states are 0 and 1 and in the limiting cases of fast and slow conformational dynamics. These results are compared with the results of numerical simulations. The accuracy and, therefore, the ability to predict model parameters depend on how fast the transition rates are compared to the photon count rate. In the limit of slow transitions, the key parameters that determine the accuracy are the number of transitions between the states and the number of independent photon sequences. In the fast transition limit, the accuracy is determined by the small fraction of photons that are correlated with their neighbors. The relative standard deviation of the relaxation rate has a “chevron” shape as a function of the transition rate in the log-log scale. The location of the minimum of this function dramatically depends on how well the FRET efficiencies of the states are separated. PMID:25612692

Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

NASA Technical Reports Server (NTRS)

Markley, F. Landis; Reynolds, Reid G.; Liu, Frank X.; Lebsock, Kenneth L.

2009-01-01

Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum that the wheels can provide. For an n-wheel configuration, the torque or momentum envelope can be obtained by projecting the n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, into three dimensional space via the 3xn matrix of wheel axes. In this paper, the properties of the projected hypercube are discussed, and algorithms are proposed for determining this maximal torque or momentum envelope for general wheel configurations. Practical strategies for distributing a prescribed torque or momentum among the n wheels are presented, with special emphasis on configurations of four, five, and six wheels.

Estimating the Maximum Magnitude of Induced Earthquakes With Dynamic Rupture Simulations

NASA Astrophysics Data System (ADS)

Gilmour, E.; Daub, E. G.

2017-12-01

Seismicity in Oklahoma has been sharply increasing as the result of wastewater injection. The earthquakes, thought to be induced from changes in pore pressure due to fluid injection, nucleate along existing faults. Induced earthquakes currently dominate central and eastern United States seismicity (Keranen et al. 2016). Induced earthquakes have only been occurring in the central US for a short time; therefore, too few induced earthquakes have been observed in this region to know their maximum magnitude. The lack of knowledge regarding the maximum magnitude of induced earthquakes means that large uncertainties exist in the seismic hazard for the central United States. While induced earthquakes follow the Gutenberg-Richter relation (van der Elst et al. 2016), it is unclear if there are limits to their magnitudes. An estimate of the maximum magnitude of the induced earthquakes is crucial for understanding their impact on seismic hazard. While other estimates of the maximum magnitude exist, those estimates are observational or statistical, and cannot take into account the possibility of larger events that have not yet been observed. Here, we take a physical approach to studying the maximum magnitude based on dynamic ruptures simulations. We run a suite of two-dimensional ruptures simulations to physically determine how ruptures propagate. The simulations use the known parameters of principle stress orientation and rupture locations. We vary the other unknown parameters of the ruptures simulations to obtain a large number of rupture simulation results reflecting different possible sets of parameters, and use these results to train a neural network to complete the ruptures simulations. Then using a Markov Chain Monte Carlo method to check different combinations of parameters, the trained neural network is used to create synthetic magnitude-frequency distributions to compare to the real earthquake catalog. This method allows us to find sets of parameters that are

Selective effects of weight and inertia on maximum lifting.

PubMed

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

2013-03-01

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

THESEUS: maximum likelihood superpositioning and analysis of macromolecular structures

PubMed Central

Theobald, Douglas L.; Wuttke, Deborah S.

2008-01-01

Summary THESEUS is a command line program for performing maximum likelihood (ML) superpositions and analysis of macromolecular structures. While conventional superpositioning methods use ordinary least-squares (LS) as the optimization criterion, ML superpositions provide substantially improved accuracy by down-weighting variable structural regions and by correcting for correlations among atoms. ML superpositioning is robust and insensitive to the specific atoms included in the analysis, and thus it does not require subjective pruning of selected variable atomic coordinates. Output includes both likelihood-based and frequentist statistics for accurate evaluation of the adequacy of a superposition and for reliable analysis of structural similarities and differences. THESEUS performs principal components analysis for analyzing the complex correlations found among atoms within a structural ensemble. PMID:16777907

High performance MIIM diode based on cobalt oxide/titanium oxide

NASA Astrophysics Data System (ADS)

Herner, S. B.; Weerakkody, A. D.; Belkadi, A.; Moddel, G.

2017-05-01

Optical rectennas for infrared energy harvesting commonly incorporate metal/double-insulator/metal diodes. Required diode characteristics include high responsivity and low resistance near zero bias with a sub-micron area, which have not been obtainable simultaneously. Diodes based on a new material set, Co/Co3O4/TiO2/Ti and an area of 0.071 μm2, provide a median maximum responsivity of 4.1 A/W, a median zero-bias responsivity of 1.2 A/W, and a median resistance of 14 kΩ. The highest performing diode has a maximum responsivity of 4.4 A/W, a zero-bias responsivity of 2.2 A/W, and a resistance of 18 kΩ.

Performance of Single-Stage Turbine of Mark 25 Torpedo Power Plant with Two Special Nozzles. III; Efficiency with Standard Rotor Blades

NASA Technical Reports Server (NTRS)

Schum, Harold J.; Whitney, Warren J.

1949-01-01

A Mark 25 torpedo power plant modified to operate as a single-stage turbine was investigated to determine the performance with two nozzle designs and a standard first-stage rotor having 0.40-inch blades with a 17O met-air angle. Both nozzles had smaller port cross-sectional areas than those nozzles of similar design, which were previously investigated. The performance of the two nozzles was compared on the basis of blade, rotor, and brake efficiencies as a function of blade-jet speed ratio for pressure ratios of 8, 15 (design), and 20. At pressure ratios of 15 and 20, the blade efficiency obtained with the nozzle having circular passages (K) was higher than that obtained with the nozzle having rectangular passages (J). At a pressure ratio of 8, the efficiencies obtained with the two nozzles were comparable for blade-jet speed ratios of less than 0.260. For blade-jet speed ratios exceeding this value, nozzle K yielded slightly higher efficiencies. The maximum blade efficiency of 0.569 was obtained with nozzle K at a pressure ratio of 8 and a blade-jet speed ratio of 0.295. At design speed and pressure ratio, nozzle K yielded a maximum blade efficiency of 0.534, an increase of 0.031 over that obtained with nozzle J. When the blade efficiencies of the two nozzles were compared with those of four other nozzles previously investigated, the maximum difference for the six nozzles with this rotor was 0.050. From, this comparison, no specific effect of nozzles size or shape on over-all performance was discernible.

5 CFR 9701.312 - Maximum rates.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Maximum rates. 9701.312 Section 9701.312... MANAGEMENT SYSTEM Pay and Pay Administration Overview of Pay System § 9701.312 Maximum rates. (a) DHS may not pay any employee an annual rate of basic pay in excess of the rate for level III of the Executive...

5 CFR 9701.312 - Maximum rates.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Maximum rates. 9701.312 Section 9701.312... MANAGEMENT SYSTEM Pay and Pay Administration Overview of Pay System § 9701.312 Maximum rates. (a) DHS may not pay any employee an annual rate of basic pay in excess of the rate for level III of the Executive...

5 CFR 9701.312 - Maximum rates.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Maximum rates. 9701.312 Section 9701.312... MANAGEMENT SYSTEM Pay and Pay Administration Overview of Pay System § 9701.312 Maximum rates. (a) DHS may not pay any employee an annual rate of basic pay in excess of the rate for level III of the Executive...

19 CFR 114.23 - Maximum period.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Maximum period. 114.23 Section 114.23 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CARNETS Processing of Carnets § 114.23 Maximum period. (a) A.T.A. carnet. No A.T.A. carnet with a period...

The Maximum Likelihood Solution for Inclination-only Data

NASA Astrophysics Data System (ADS)

Arason, P.; Levi, S.

2006-12-01

frequently for certain data sets, and relatively small perturbations in the data will drive the maxima to the boundary. We interpret this to indicate that, for such data sets, the information needed to separate the mean inclination and the precision parameter is permanently lost. To assess the reliability and accuracy of our method we generated large number of random Fisher-distributed data sets and used seven methods to estimate the mean inclination and precision paramenter. These comparisons are described by Levi and Arason at the 2006 AGU Fall meeting. The results of the various methods is very favourable to our new robust maximum likelihood method, which, on average, is the most reliable, and the mean inclination estimates are the least biased toward shallow values. Further information on our inclination-only analysis can be obtained from: http://www.vedur.is/~arason/paleomag

14 CFR 23.1524 - Maximum passenger seating configuration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum passenger seating configuration. 23.1524 Section 23.1524 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Operating Limitations and Information § 23.1524 Maximum passenger seating configuration. The maximum...

Maximum cycle work output optimization for generalized radiative law Otto cycle engines

NASA Astrophysics Data System (ADS)

Xia, Shaojun; Chen, Lingen; Sun, Fengrui

2016-11-01

An Otto cycle internal combustion engine which includes thermal and friction losses is investigated by finite-time thermodynamics, and the optimization objective is the maximum cycle work output. The thermal energy transfer from the working substance to the cylinder inner wall follows the generalized radiative law (q∝Δ (Tn)). Under the condition that all of the fuel consumption, the compression ratio and the cycle period are given, the optimal piston trajectories for both the examples with unlimited and limited accelerations on every stroke are determined, and the cycle-period distribution among all strokes is also optimized. Numerical calculation results for the case of radiative law are provided and compared with those obtained for the cases of Newtonian law and linear phenomenological law. The results indicate that the optimal piston trajectory on each stroke contains three sections, which consist of an original maximum-acceleration and a terminal maximum-deceleration parts; for the case of radiative law, optimizing the piston motion path can achieve an improvement of more than 20% in both the cycle-work output and the second-law efficiency of the Otto cycle compared with the conventional near-sinusoidal operation, and heat transfer mechanisms have both qualitative and quantitative influences on the optimal paths of piston movements.

48 CFR 209.105-1 - Obtaining information.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Performance Information Retrieval System (PPIRS), available at http://www.ppirs.gov. Information relating to... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Obtaining information. 209....105-1 Obtaining information. (1) For guidance on using the System for Award Management Exclusions, see...

Psychophysical basis for maximum pushing and pulling forces: A review and recommendations.

PubMed

Garg, Arun; Waters, Thomas; Kapellusch, Jay; Karwowski, Waldemar

2014-03-01

The objective of this paper was to perform a comprehensive review of psychophysically determined maximum acceptable pushing and pulling forces. Factors affecting pushing and pulling forces are identified and discussed. Recent studies show a significant decrease (compared to previous studies) in maximum acceptable forces for males but not for females when pushing and pulling on a treadmill. A comparison of pushing and pulling forces measured using a high inertia cart with those measured on a treadmill shows that the pushing and pulling forces using high inertia cart are higher for males but are about the same for females. It is concluded that the recommendations of Snook and Ciriello (1991) for pushing and pulling forces are still valid and provide reasonable recommendations for ergonomics practitioners. Regression equations as a function of handle height, frequency of exertion and pushing/pulling distance are provided to estimate maximum initial and sustained forces for pushing and pulling acceptable to 75% male and female workers. At present it is not clear whether pushing or pulling should be favored. Similarly, it is not clear what handle heights would be optimal for pushing and pulling. Epidemiological studies are needed to determine relationships between psychophysically determined maximum acceptable pushing and pulling forces and risk of musculoskeletal injuries, in particular to low back and shoulders.

A High Performance Micro Channel Interface for Real-Time Industrial Image Processing

Treesearch

Thomas H. Drayer; Joseph G. Tront; Richard W. Conners

1995-01-01

Data collection and transfer devices are critical to the performance of any machine vision system. The interface described in this paper collects image data from a color line scan camera and transfers the data obtained into the system memory of a Micro Channel-based host computer. A maximum data transfer rate of 20 Mbytes/sec can be achieved using the DMA capabilities...

Maximum permissible voltage of YBCO coated conductors

NASA Astrophysics Data System (ADS)

Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.

2014-06-01

Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

30 CFR 56.19062 - Maximum acceleration and deceleration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum acceleration and deceleration. 56.19062 Section 56.19062 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoisting Procedures § 56.19062 Maximum acceleration and deceleration. Maximum normal operating...

30 CFR 57.19062 - Maximum acceleration and deceleration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum acceleration and deceleration. 57.19062 Section 57.19062 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoisting Procedures § 57.19062 Maximum acceleration and deceleration. Maximum normal operating...

Maximum efficiency of state-space models of nanoscale energy conversion devices

NASA Astrophysics Data System (ADS)

Einax, Mario; Nitzan, Abraham

2016-07-01

The performance of nano-scale energy conversion devices is studied in the framework of state-space models where a device is described by a graph comprising states and transitions between them represented by nodes and links, respectively. Particular segments of this network represent input (driving) and output processes whose properly chosen flux ratio provides the energy conversion efficiency. Simple cyclical graphs yield Carnot efficiency for the maximum conversion yield. We give general proof that opening a link that separate between the two driving segments always leads to reduced efficiency. We illustrate these general result with simple models of a thermoelectric nanodevice and an organic photovoltaic cell. In the latter an intersecting link of the above type corresponds to non-radiative carriers recombination and the reduced maximum efficiency is manifested as a smaller open-circuit voltage.

Maximum efficiency of state-space models of nanoscale energy conversion devices.

PubMed

Einax, Mario; Nitzan, Abraham

2016-07-07

The performance of nano-scale energy conversion devices is studied in the framework of state-space models where a device is described by a graph comprising states and transitions between them represented by nodes and links, respectively. Particular segments of this network represent input (driving) and output processes whose properly chosen flux ratio provides the energy conversion efficiency. Simple cyclical graphs yield Carnot efficiency for the maximum conversion yield. We give general proof that opening a link that separate between the two driving segments always leads to reduced efficiency. We illustrate these general result with simple models of a thermoelectric nanodevice and an organic photovoltaic cell. In the latter an intersecting link of the above type corresponds to non-radiative carriers recombination and the reduced maximum efficiency is manifested as a smaller open-circuit voltage.

An analysis of functional shoulder movements during task performance using Dartfish movement analysis software.

PubMed

Khadilkar, Leenesh; MacDermid, Joy C; Sinden, Kathryn E; Jenkyn, Thomas R; Birmingham, Trevor B; Athwal, George S

2014-01-01

Video-based movement analysis software (Dartfish) has potential for clinical applications for understanding shoulder motion if functional measures can be reliably obtained. The primary purpose of this study was to describe the functional range of motion (ROM) of the shoulder used to perform a subset of functional tasks. A second purpose was to assess the reliability of functional ROM measurements obtained by different raters using Dartfish software. Ten healthy participants, mean age 29 ± 5 years, were videotaped while performing five tasks selected from the Disabilities of the Arm, Shoulder and Hand (DASH). Video cameras and markers were used to obtain video images suitable for analysis in Dartfish software. Three repetitions of each task were performed. Shoulder movements from all three repetitions were analyzed using Dartfish software. The tracking tool of the Dartfish software was used to obtain shoulder joint angles and arcs of motion. Test-retest and inter-rater reliability of the measurements were evaluated using intraclass correlation coefficients (ICC). Maximum (coronal plane) abduction (118° ± 16°) and (sagittal plane) flexion (111° ± 15°) was observed during 'washing one's hair;' maximum extension (-68° ± 9°) was identified during 'washing one's own back.' Minimum shoulder ROM was observed during 'opening a tight jar' (33° ± 13° abduction and 13° ± 19° flexion). Test-retest reliability (ICC = 0.45 to 0.94) suggests high inter-individual task variability, and inter-rater reliability (ICC = 0.68 to 1.00) showed moderate to excellent agreement. KEY FINDINGS INCLUDE: 1) functional shoulder ROM identified in this study compared to similar studies; 2) healthy individuals require less than full ROM when performing five common ADL tasks 3) high participant variability was observed during performance of the five ADL tasks; and 4) Dartfish software provides a clinically relevant tool to analyze shoulder function.

42 CFR 457.560 - Cumulative cost-sharing maximum.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Cumulative cost-sharing maximum. 457.560 Section... State Plan Requirements: Enrollee Financial Responsibilities § 457.560 Cumulative cost-sharing maximum... writing and orally if appropriate of their individual cumulative cost-sharing maximum amount at the time...

49 CFR 192.620 - Alternative maximum allowable operating pressure for certain steel pipelines.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of a maximum allowable operating pressure based on higher stress levels in the following areas: Take... pipeline at the increased stress level under this section with conventional operation; and (ii) Describe... targeted audience; and (B) Include information about the integrity management activities performed under...

49 CFR 192.620 - Alternative maximum allowable operating pressure for certain steel pipelines.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of a maximum allowable operating pressure based on higher stress levels in the following areas: Take... pipeline at the increased stress level under this section with conventional operation; and (ii) Describe... targeted audience; and (B) Include information about the integrity management activities performed under...

49 CFR 192.620 - Alternative maximum allowable operating pressure for certain steel pipelines.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of a maximum allowable operating pressure based on higher stress levels in the following areas: Take... pipeline at the increased stress level under this section with conventional operation; and (ii) Describe... targeted audience; and (B) Include information about the integrity management activities performed under...

Developing a diagnostic tool for measuring maximum effective temperature within high pressure electrodeless discharges

NASA Astrophysics Data System (ADS)

Whiting, Michael; Preston, Barry; Mucklejohn, Stuart; Santos, Monica; Lister, Graeme

2016-09-01

Here we present an investigation into the feasibility of creating a diagnostic tool for obtaining maximum arc temperature measurements within a high pressure electrodeless discharge; utilizing integrating sphere measurements of optically thin lines emitted from mercury atoms within commercially available high pressure mercury lamp arc tubes. The optically thin lines chosen were 577 nm and 1014 nm from a 250 W high pressure mercury lamp operated at various powers. The effective temperature could be calculated by considering the relative intensities of the two optically thin lines and comparison with the theoretical ratio of the temperature dependent power emitted from the lines derived from the atomic spectral data provided by NIST. The calculations gave effective arc temperatures of 5755, 5804 and 5820 K at 200, 225, 250 W respectively. This method was subsequently used as a basis for determining maximum effective arc temperature within microwave-driven electrodeless discharge capsules, with varying mercury content of 6.07, 9.4 and 12.95 mg within 1 × 10-6 m3 giving maximum effective temperatures of 5163, 4768 and 4715 K respectively at 240 W.

Maximum Neutral Buoyancy Depth of Juvenile Chinook Salmon: Implications for Survival during Hydroturbine Passage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pflugrath, Brett D.; Brown, Richard S.; Carlson, Thomas J.

This study investigated the maximum depth at which juvenile Chinook salmon Oncorhynchus tshawytscha can acclimate by attaining neutral buoyancy. Depth of neutral buoyancy is dependent upon the volume of gas within the swim bladder, which greatly influences the occurrence of injuries to fish passing through hydroturbines. We used two methods to obtain maximum swim bladder volumes that were transformed into depth estimations - the increased excess mass test (IEMT) and the swim bladder rupture test (SBRT). In the IEMT, weights were surgically added to the fishes exterior, requiring the fish to increase swim bladder volume in order to remain neutrallymore » buoyant. SBRT entailed removing and artificially increasing swim bladder volume through decompression. From these tests, we estimate the maximum acclimation depth for juvenile Chinook salmon is a median of 6.7m (range = 4.6-11.6 m). These findings have important implications to survival estimates, studies using tags, hydropower operations, and survival of juvenile salmon that pass through large Kaplan turbines typical of those found within the Columbia and Snake River hydropower system.« less

Porous materials based on foaming solutions obtained from industrial waste

NASA Astrophysics Data System (ADS)

Starostina, I. V.; Antipova, A. N.; Ovcharova, I. V.; Starostina, Yu L.

2018-03-01

This study analyzes foam concrete production efficiency. Research has shown the possibility of using a newly-designed protein-based foaming agent to produce porous materials using gypsum and cement binders. The protein foaming agent is obtained by alkaline hydrolysis of a raw mixture consisting of industrial waste in an electromagnetic field. The mixture consists of spent biomass of the Aspergillus niger fungus and dust from burning furnaces used in cement production. Varying the content of the foaming agent allows obtaining gypsum binder-based foam concretes with the density of 200-500 kg/m3 and compressive strength of 0.1-1.0 MPa, which can be used for thermal and sound insulation of building interiors. Cement binders were used to obtain structural and thermal insulation materials with the density of 300-950 kg/m3 and compressive strength of 0.9-9.0 MPa. The maximum operating temperature of cement-based foam concretes is 500°C because it provides the shrinkage of less than 2%.

Estimation Methods for Non-Homogeneous Regression - Minimum CRPS vs Maximum Likelihood

NASA Astrophysics Data System (ADS)

Gebetsberger, Manuel; Messner, Jakob W.; Mayr, Georg J.; Zeileis, Achim

2017-04-01

Non-homogeneous regression models are widely used to statistically post-process numerical weather prediction models. Such regression models correct for errors in mean and variance and are capable to forecast a full probability distribution. In order to estimate the corresponding regression coefficients, CRPS minimization is performed in many meteorological post-processing studies since the last decade. In contrast to maximum likelihood estimation, CRPS minimization is claimed to yield more calibrated forecasts. Theoretically, both scoring rules used as an optimization score should be able to locate a similar and unknown optimum. Discrepancies might result from a wrong distributional assumption of the observed quantity. To address this theoretical concept, this study compares maximum likelihood and minimum CRPS estimation for different distributional assumptions. First, a synthetic case study shows that, for an appropriate distributional assumption, both estimation methods yield to similar regression coefficients. The log-likelihood estimator is slightly more efficient. A real world case study for surface temperature forecasts at different sites in Europe confirms these results but shows that surface temperature does not always follow the classical assumption of a Gaussian distribution. KEYWORDS: ensemble post-processing, maximum likelihood estimation, CRPS minimization, probabilistic temperature forecasting, distributional regression models

Maximum bite force in elderly indigenous and non-indigenous denture wearers.

PubMed

Borie, Eduardo; Orsi, Iara A; Fuentes, Ramón; Beltrán, Víctor; Navarro, Pablo; Pareja, Felipe; Raimundo, Lariça B

2014-01-01

The aim of this study was to compare the measures of maximum bite force (MBF) in elderly edentulous indigenous (Mapuche) and non-indigenous individuals with new complete dentures at two different measuring times. A sample of 100 elderly subjects was divided into two groups: 50 indigenous and 50 non-indigenous, each including 25 females and 25 males. All individuals were totally edentulous, with new maxillary and mandibular removable complete dentures. Measurements were taken at the time of new prosthesis placement and after 1 month of use. Subjects were asked to perform with maximum effort three bites per side at maximum intercuspidation, with a rest time of 2 minutes in between. Statistics were analyzed with Student 's t-test. The MBF values were significantly higher in indigenous than non-indigenous subjects. Force after 1 month of wearing the new prosthesis was significantly higher than at the time of new prosthesis placement. No significant difference was found between sides. Elderly indigenous complete denture wearers had the greatest MBF values. Denture wearers were observed to undergo an adaptation process to the new prosthesis, with MBF increasing considerably after one month of use.

Do we perform surgical programming well? How can we improve it?

PubMed

Albareda, J; Clavel, D; Mahulea, C; Blanco, N; Ezquerra, L; Gómez, J; Silva, J M

The objective is to establish the duration of our interventions, intermediate times and surgical performance. This will create a virtual waiting list to apply a mathematical programme that performs programming with maximum performance. Retrospective review of 49 surgical sessions obtaining the delay in start time, intermediate time and surgical performance. Retrospective review of 4,045 interventions performed in the last 3 years to obtain the average duration of each type of surgery. Creation of a virtual waiting list of 700 patients in order to perform virtual programming through the MIQCP-P until achieving optimal performance. Our surgical performance with manual programming was 75.9%, ending 22.4% later than 3pm. The performance in the days without suspensions was 78.4%. The delay at start time was 9.7min. The optimum performance was 77.5% with a confidence of finishing before 15h of 80.6%. The waiting list has been scheduled in 254 sessions. Our manual surgical performance without suspensions (78.4%) was superior to the optimal (77.5%), generating days finished later than 3pm and suspensions. The possibilities for improvement are to achieve punctuality at the start time and adjust the schedule to the ideal performance. The virtual programming has allowed us to obtain our ideal performance and to establish the number of operating rooms necessary to solve the waiting list created. The data obtained in virtual mathematical programming are reliable enough to implement this model with guarantees. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

36 CFR 20.3 - Maximum number of permittees.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Maximum number of permittees... INTERIOR ISLE ROYALE NATIONAL PARK; COMMERCIAL FISHING § 20.3 Maximum number of permittees. Commercial fishermen to whom the annual revocable permits may be granted shall not exceed the maximum number of persons...

44 CFR 208.12 - Maximum Pay Rate Table.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Maximum Pay Rate Table. 208... § 208.12 Maximum Pay Rate Table. (a) Purpose. This section establishes the process for creating and updating the Maximum Pay Rate Table (Table), and the Table's use to reimburse Affiliated Personnel (Task...

13 CFR 107.840 - Maximum term of Financing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum term of Financing. 107.840... COMPANIES Financing of Small Businesses by Licensees Structuring Licensee's Financing of An Eligible Small Business: Terms and Conditions of Financing § 107.840 Maximum term of Financing. The maximum term of any...

Maximum spreading of liquid drop on various substrates with different wettabilities

NASA Astrophysics Data System (ADS)

Choudhury, Raihan; Choi, Junho; Yang, Sangsun; Kim, Yong-Jin; Lee, Donggeun

2017-09-01

This paper describes a novel model developed for a priori prediction of the maximal spread of a liquid drop on a surface. As a first step, a series of experiments were conducted under precise control of the initial drop diameter, its falling height, roughness, and wettability of dry surfaces. The transient liquid spreading was recorded by a high-speed camera to obtain its maximum spreading under various conditions. Eight preexisting models were tested for accurate prediction of the maximum spread; however, most of the model predictions were not satisfactory except one, in comparison with our experimental data. A comparative scaling analysis of the literature models was conducted to elucidate the condition-dependent prediction characteristics of the models. The conditioned bias in the predictions was mainly attributed to the inappropriate formulations of viscous dissipation or interfacial energy of liquid on the surface. Hence, a novel model based on energy balance during liquid impact was developed to overcome the limitations of the previous models. As a result, the present model was quite successful in predicting the liquid spread in all the conditions.

48 CFR 209.105-1 - Obtaining information.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Obtaining information. 209....105-1 Obtaining information. (1) For guidance on using the Exclusions section of the System for Award... responsibility (see FAR 9.104-1(c)). One source of information relating to contractor performance is the Past...

On the Performance of Maximum Likelihood versus Means and Variance Adjusted Weighted Least Squares Estimation in CFA

ERIC Educational Resources Information Center

Beauducel, Andre; Herzberg, Philipp Yorck

2006-01-01

This simulation study compared maximum likelihood (ML) estimation with weighted least squares means and variance adjusted (WLSMV) estimation. The study was based on confirmatory factor analyses with 1, 2, 4, and 8 factors, based on 250, 500, 750, and 1,000 cases, and on 5, 10, 20, and 40 variables with 2, 3, 4, 5, and 6 categories. There was no…

Simple Statistical Model to Quantify Maximum Expected EMC in Spacecraft and Avionics Boxes

NASA Technical Reports Server (NTRS)

Trout, Dawn H.; Bremner, Paul

2014-01-01

This study shows cumulative distribution function (CDF) comparisons of composite a fairing electromagnetic field data obtained by computational electromagnetic 3D full wave modeling and laboratory testing. Test and model data correlation is shown. In addition, this presentation shows application of the power balance and extention of this method to predict the variance and maximum exptected mean of the E-field data. This is valuable for large scale evaluations of transmission inside cavities.

Maximum likelihood estimation for Cox's regression model under nested case-control sampling.

PubMed

Scheike, Thomas H; Juul, Anders

2004-04-01

Nested case-control sampling is designed to reduce the costs of large cohort studies. It is important to estimate the parameters of interest as efficiently as possible. We present a new maximum likelihood estimator (MLE) for nested case-control sampling in the context of Cox's proportional hazards model. The MLE is computed by the EM-algorithm, which is easy to implement in the proportional hazards setting. Standard errors are estimated by a numerical profile likelihood approach based on EM aided differentiation. The work was motivated by a nested case-control study that hypothesized that insulin-like growth factor I was associated with ischemic heart disease. The study was based on a population of 3784 Danes and 231 cases of ischemic heart disease where controls were matched on age and gender. We illustrate the use of the MLE for these data and show how the maximum likelihood framework can be used to obtain information additional to the relative risk estimates of covariates.

Maximum likelihood decoding analysis of Accumulate-Repeat-Accumulate Codes

NASA Technical Reports Server (NTRS)

Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

2004-01-01

Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve good performance. However, they cannot compete with Turbo codes or low-density parity check codes (LDPC) as far as performance is concerned. The Accumulate Repeat Accumulate (ARA) codes, as a subclass of LDPC codes, are obtained by adding a pre-coder in front of RA codes with puncturing where an accumulator is chosen as a precoder. These codes not only are very simple, but also achieve excellent performance with iterative decoding. In this paper, the performance of these codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. The weight distribution of some simple ARA codes is obtained, and through existing tightest bounds we have shown the ML SNR threshold of ARA codes approaches very closely to the performance of random codes. We have shown that the use of precoder improves the SNR threshold but interleaving gain remains unchanged with respect to RA code with puncturing.

Text Summarization Model based on Maximum Coverage Problem and its Variant

NASA Astrophysics Data System (ADS)

Takamura, Hiroya; Okumura, Manabu

We discuss text summarization in terms of maximum coverage problem and its variant. To solve the optimization problem, we applied some decoding algorithms including the ones never used in this summarization formulation, such as a greedy algorithm with performance guarantee, a randomized algorithm, and a branch-and-bound method. We conduct comparative experiments. On the basis of the experimental results, we also augment the summarization model so that it takes into account the relevance to the document cluster. Through experiments, we showed that the augmented model is at least comparable to the best-performing method of DUC'04.

20 CFR 226.52 - Total annuity subject to maximum.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Total annuity subject to maximum. 226.52... COMPUTING EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Railroad Retirement Family Maximum § 226.52 Total annuity subject to maximum. The total annuity amount which is compared to the maximum monthly amount to...

40 CFR 35.2205 - Maximum allowable project cost.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum allowable project cost. 35.2205... ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2205 Maximum allowable... regulation, the maximum allowable project cost will be the sum of: (1) The allowable cost of the following...

A comparative study of artificial intelligent-based maximum power point tracking for photovoltaic systems

NASA Astrophysics Data System (ADS)

Hussain Mutlag, Ammar; Mohamed, Azah; Shareef, Hussain

2016-03-01

Maximum power point tracking (MPPT) is normally required to improve the performance of photovoltaic (PV) systems. This paper presents artificial intelligent-based maximum power point tracking (AI-MPPT) by considering three artificial intelligent techniques, namely, artificial neural network (ANN), adaptive neuro fuzzy inference system with seven triangular fuzzy sets (7-tri), and adaptive neuro fuzzy inference system with seven gbell fuzzy sets. The AI-MPPT is designed for the 25 SolarTIFSTF-120P6 PV panels, with the capacity of 3 kW peak. A complete PV system is modelled using 300,000 data samples and simulated in the MATLAB/SIMULINK. The AI-MPPT has been tested under real environmental conditions for two days from 8 am to 18 pm. The results showed that the ANN based MPPT gives the most accurate performance and then followed by the 7-tri-based MPPT.

Effect of atomic layer deposition temperature on the performance of top-down ZnO nanowire transistors

PubMed Central

2014-01-01

This paper studies the effect of atomic layer deposition (ALD) temperature on the performance of top-down ZnO nanowire transistors. Electrical characteristics are presented for 10-μm ZnO nanowire field-effect transistors (FETs) and for deposition temperatures in the range 120°C to 210°C. Well-behaved transistor output characteristics are obtained for all deposition temperatures. It is shown that the maximum field-effect mobility occurs for an ALD temperature of 190°C. This maximum field-effect mobility corresponds with a maximum Hall effect bulk mobility and with a ZnO film that is stoichiometric. The optimized transistors have a field-effect mobility of 10 cm2/V.s, which is approximately ten times higher than can typically be achieved in thin-film amorphous silicon transistors. Furthermore, simulations indicate that the drain current and field-effect mobility extraction are limited by the contact resistance. When the effects of contact resistance are de-embedded, a field-effect mobility of 129 cm2/V.s is obtained. This excellent result demonstrates the promise of top-down ZnO nanowire technology for a wide variety of applications such as high-performance thin-film electronics, flexible electronics, and biosensing. PMID:25276107

49 CFR 236.55 - Dead section; maximum length.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Dead section; maximum length. 236.55 Section 236... Instructions: All Systems Track Circuits § 236.55 Dead section; maximum length. Where dead section exceeds 35... over such dead section is less than 35 feet, the maximum length of the dead section shall not exceed...

49 CFR 236.55 - Dead section; maximum length.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Dead section; maximum length. 236.55 Section 236... Instructions: All Systems Track Circuits § 236.55 Dead section; maximum length. Where dead section exceeds 35... over such dead section is less than 35 feet, the maximum length of the dead section shall not exceed...

49 CFR 236.55 - Dead section; maximum length.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Dead section; maximum length. 236.55 Section 236... Instructions: All Systems Track Circuits § 236.55 Dead section; maximum length. Where dead section exceeds 35... over such dead section is less than 35 feet, the maximum length of the dead section shall not exceed...

49 CFR 236.55 - Dead section; maximum length.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Dead section; maximum length. 236.55 Section 236... Instructions: All Systems Track Circuits § 236.55 Dead section; maximum length. Where dead section exceeds 35... over such dead section is less than 35 feet, the maximum length of the dead section shall not exceed...

49 CFR 236.55 - Dead section; maximum length.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Dead section; maximum length. 236.55 Section 236... Instructions: All Systems Track Circuits § 236.55 Dead section; maximum length. Where dead section exceeds 35... over such dead section is less than 35 feet, the maximum length of the dead section shall not exceed...

14 CFR 25.1505 - Maximum operating limit speed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not be...

14 CFR 25.1505 - Maximum operating limit speed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not be...

Does combined strength training and local vibration improve isometric maximum force? A pilot study.

PubMed

Goebel, Ruben; Haddad, Monoem; Kleinöder, Heinz; Yue, Zengyuan; Heinen, Thomas; Mester, Joachim

2017-01-01

The aim of the study was to determine whether a combination of strength training (ST) and local vibration (LV) improved the isometric maximum force of arm flexor muscles. ST was applied to the left arm of the subjects; LV was applied to the right arm of the same subjects. The main aim was to examine the effect of LV during a dumbbell biceps curl (Scott Curl) on isometric maximum force of the opposite muscle among the same subjects. It is hypothesized, that the intervention with LV produces a greater gain in isometric force of the arm flexors than ST. Twenty-seven collegiate students participated in the study. The training load was 70% of the individual 1 RM. Four sets with 12 repetitions were performed three times per week during four weeks. The right arm of all subjects represented the vibration trained body side (VS) and the left arm served as the traditional trained body side (TTS). A significant increase of isometric maximum force in both body sides (Arms) occurred. VS, however, significantly increased isometric maximum force about 43% in contrast to 22% of the TTS. The combined intervention of ST and LC improves isometric maximum force of arm flexor muscles. III.

40 CFR 94.107 - Determination of maximum test speed.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Determination of maximum test speed... Determination of maximum test speed. (a) Overview. This section specifies how to determine maximum test speed from a lug curve. This maximum test speed is used in §§ 94.105, 94.106, and § 94.109 (including the...

40 CFR 94.107 - Determination of maximum test speed.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Determination of maximum test speed... Determination of maximum test speed. (a) Overview. This section specifies how to determine maximum test speed from a lug curve. This maximum test speed is used in §§ 94.105, 94.106, and § 94.109 (including the...

Optimal flapping wing for maximum vertical aerodynamic force in hover: twisted or flat?

PubMed

Phan, Hoang Vu; Truong, Quang Tri; Au, Thi Kim Loan; Park, Hoon Cheol

2016-07-08

This work presents a parametric study, using the unsteady blade element theory, to investigate the role of twist in a hovering flapping wing. For the investigation, a flapping-wing system was developed to create a wing motion of large flapping amplitude. Three-dimensional kinematics of a passively twisted wing, which is capable of creating a linearly variable geometric angle of attack (AoA) along the wingspan, was measured during the flapping motion and used for the analysis. Several negative twist or wash-out configurations with different values of twist angle, which is defined as the difference in the average geometric AoAs at the wing root and the wing tip, were obtained from the measured wing kinematics through linear interpolation and extrapolation. The aerodynamic force generation and aerodynamic power consumption of these twisted wings were obtained and compared with those of flat wings. For the same aerodynamic power consumption, the vertical aerodynamic forces produced by the negatively twisted wings are approximately 10%-20% less than those produced by the flat wings. However, these twisted wings require approximately 1%-6% more power than flat wings to produce the same vertical force. In addition, the maximum-force-producing twisted wing, which was found to be the positive twist or wash-in configuration, was used for comparison with the maximum-force-producing flat wing. The results revealed that the vertical aerodynamic force and aerodynamic power consumption of the two types of wings are almost identical for the hovering condition. The power loading of the positively twisted wing is only approximately 2% higher than that of the maximum-force-producing flat wing. Thus, the flat wing with proper wing kinematics (or wing rotation) can be regarded as a simple and efficient candidate for the development of hovering flapping-wing micro air vehicle.

Performance analysis for minimally nonlinear irreversible refrigerators at finite cooling power

NASA Astrophysics Data System (ADS)

Long, Rui; Liu, Zhichun; Liu, Wei

2018-04-01

The coefficient of performance (COP) for general refrigerators at finite cooling power have been systematically researched through the minimally nonlinear irreversible model, and its lower and upper bounds in different operating regions have been proposed. Under the tight coupling conditions, we have calculated the universal COP bounds under the χ figure of merit in different operating regions. When the refrigerator operates in the region with lower external flux, we obtained the general bounds (0 < ε <(√{ 9 + 8εC } - 3) / 2) under the χ figure of merit. We have also calculated the universal bounds for maximum gain in COP under different operating regions to give a further insight into the COP gain with the cooling power away from the maximum one. When the refrigerator operates in the region located between maximum cooling power and maximum COP with lower external flux, the upper bound for COP and the lower bound for relative gain in COP present large values, compared to a relative small loss from the maximum cooling power. If the cooling power is the main objective, it is desirable to operate the refrigerator at a slightly lower cooling power than at the maximum one, where a small loss in the cooling power induces a much larger COP enhancement.

Essential Oil of Amomum maximum Roxb. and Its Bioactivities against Two Stored-Product Insects.

PubMed

Guo, Shan-Shan; You, Chun-Xue; Liang, Jun-Yu; Zhang, Wen-Juan; Yang, Kai; Geng, Zhu-Feng; Wang, Cheng-Fang; Du, Shu-Shan; Lei, Ning

2015-01-01

Amomum maximum Roxb. is a perennial herb distributed in South China and Southeast Asia. The objective of this work was to analyze the chemical constituents and assess insecticidal and repellent activities of the essential oil from Amomum maximum fruits against Tribolium castaneum (Herbst) and Liposcelis bostrychophila (Badonnel). The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. The main components of the essential oil were identified to be β-pinene (23.39%), β-caryophyllene (16.43%), α-pinene (7.55%), sylvestrene (6.61%) and ç-cadinene (4.19%). It was found that the essential oil of A. maximum fruits possessed contact and fumigant toxicities against T. castaneum adults (LD50 = 29.57 μg/adult and LC(50) = 23.09 mg/L air, respectively) and showed contact toxicity against L. bostrychophila (LD(50) = 67.46 μg/cm(2)). Repellency of the crude oil was also evaluated. After 2 h treatment, the essential oil possessed 100% repellency at 78.63 nL/cm(2) against T. castaneum and 84% repellency at 63.17 nL/cm(2) against L. bostrychophila. The results indicated that the essential oil of A. maximum fruits had the potential to be developed as a natural insecticide and repellent for control of T. castaneum and L. bostrychophila.

The turbulence structure of katabatic flows below and above wind-speed maximum

NASA Astrophysics Data System (ADS)

Grachev, Andrey; Leo, Laura; Di Sabatino, Silvana; Fernando, Harindra; Pardyjak, Eric; Fairall, Christopher

2015-04-01

Measurements of atmospheric small-scale turbulence made over the complex-terrain at the US Army Dugway Proving Grounds in Utah during the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program are used to describe the turbulence structure of katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels (up to seven) on four towers deployed along East lower slope (2-4 degrees) of Granite Mountain. The multi-level, multi-tower observations obtained during a 30-day long MATERHORN-Fall field campaign in September-October 2102 allow studying temporal and spatial structure of nocturnal slope flows in detail. In this study, we focus on the various statistics (fluxes, variances, spectra, cospectra, etc.) of the small-scale turbulence of katabatic winds. Observed vertical profiles of velocity, turbulent fluxes, and other quantities show steep gradients near the surface but in the layer above the slope jet these variables vary with height more slowly than near the surface. It is found that vertical momentum flux and horizontal heat (buoyancy) flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed downward (upward) whereas the horizontal heat flux is downslope (upslope) below (above) the wind maximum. Our study, therefore, suggests that a position of the jet speed maximum can be derived from linear interpolation between positive and negative values of the momentum flux (or the horizontal heat flux) and determination of a height where a flux becomes zero. It is shown that the standard deviations of all wind speed components (and therefore the turbulent kinetic energy) and the dissipation rate of turbulent kinetic energy have a local minimum, whereas the standard deviation of air temperature has an absolute maximum at the height of wind speed maximum. We report several cases when the destructive effect of vertical heat

Psychophysical basis for maximum pushing and pulling forces: A review and recommendations

PubMed Central

Garg, Arun; Waters, Thomas; Kapellusch, Jay; Karwowski, Waldemar

2015-01-01

The objective of this paper was to perform a comprehensive review of psychophysically determined maximum acceptable pushing and pulling forces. Factors affecting pushing and pulling forces are identified and discussed. Recent studies show a significant decrease (compared to previous studies) in maximum acceptable forces for males but not for females when pushing and pulling on a treadmill. A comparison of pushing and pulling forces measured using a high inertia cart with those measured on a treadmill shows that the pushing and pulling forces using high inertia cart are higher for males but are about the same for females. It is concluded that the recommendations of Snook and Ciriello (1991) for pushing and pulling forces are still valid and provide reasonable recommendations for ergonomics practitioners. Regression equations as a function of handle height, frequency of exertion and pushing/pulling distance are provided to estimate maximum initial and sustained forces for pushing and pulling acceptable to 75% male and female workers. At present it is not clear whether pushing or pulling should be favored. Similarly, it is not clear what handle heights would be optimal for pushing and pulling. Epidemiological studies are needed to determine relationships between psychophysically determined maximum acceptable pushing and pulling forces and risk of musculoskeletal injuries, in particular to low back and shoulders. PMID:26664045

Preliminary Results of an Altitude-Wind-Tunnel Investigation of a TG-100A Gas Turbine-Propeller Engine. 4; Compressor and Turbine Performance Characteristics

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Saari, Martin J.

1947-01-01

As part of an investigation of the performance and operational characteristics of the TG-100A gas turbine-propeller engine, conducted in the Cleveland altitude wind tunnel, the performance characteristics of the compressor and the turbine were obtained. The data presented were obtained at a compressor-inlet ram-pressure ratio of 1.00 for altitudes from 5000 to 35,000 feet, engine speeds from 8000 to 13,000 rpm, and turbine-inlet temperatures from 1400 to 2100R. The highest compressor pressure ratio was 6.15 at a corrected air flow of 23.7 pounds per second and a corrected turbine-inlet temperature of 2475R. Peak adiabatic compressor efficiencies of about 77 percent were obtained near the value of corrected air flow corresponding to a corrected engine speed of 13,000 rpm. This maximum efficiency may be somewhat low, however, because of dirt accumulations on the compressor blades. A maximum adiabatic turbine efficiency of 81.5 percent was obtained at rated engine speed for all altitudes and turbine-inlet temperatures investigated.

Tethered swimming can be used to evaluate force contribution for short-distance swimming performance.

PubMed

Morouço, Pedro G; Marinho, Daniel A; Keskinen, Kari L; Badillo, Juan J; Marques, Mário C

2014-11-01

The purpose of this study was two-fold: (a) to compare stroke and the physiological responses between maximal tethered and free front crawl swimming and (b) to evaluate the contribution of force exertion for swimming performance over short distances. A total of 34 male swimmers, representing various levels of competitive performance, participated in this study. Each participant was tested in both a 30-second maximal tethered swimming test and a 50-m free swimming test. The tethered force parameters, the swimming speed, stroke (stroke rate [SR]), and the physiological responses (increase in blood lactate concentration [ΔBLa], heart rate, and rate of perceived exertion) were recorded and calculated. The results showed no differences in stroke and the physiological responses between tethered and free swimming, with a high level of agreement for the SR and ΔBLa. A strong correlation was obtained between the maximum impulse of force per stroke and the speed (r = 0.91; p < 0.001). Multiple regression analysis revealed that the maximum impulse and SR in the tethered condition explained 84% of the free swimming performance. The relationship between the swimming speed and maximum force tended to be nonlinear, whereas linear relationships were observed with the maximum impulse. This study demonstrates that tethered swimming does not significantly alter stroke and the physiological responses compared with free swimming, and that the maximum impulse per stroke should be used to evaluate the balance between force and the ability to effectively apply force during sprint swimming. Consequently, coaches can rely on tethered forces to identify strength deficits and improve swimming performance over short distances.

Comparison of Water-Load Distributions Obtained during Seaplane Landings with Bureau of Aeronautics Specifications. TED No. NACA 2413

NASA Technical Reports Server (NTRS)

Smiley, Robert F.; Haines, Gilbert A.

1949-01-01

Bureau of Aeronautics Design Specifications SS-IC-2 for water loads in sheltered water are compared with experimental water loads obtained during a full--scale landing investigation. This investigation was conducted with a JRS-1 flying boat which has a 20 degrees dead-rise V-bottom with a partial chine flare. The range of landing conditions included airspeeds between 88 and 126 feet per second, sinking speeds between 1.6 and 9.1 feet per second, flight angles less than 6 degrees, and trims between 2 degrees and 12 degrees. Landings were moderate and were made in calm water. Measurements were obtained of maximum over-all loads, maximum pitching moments, and pressure distributions. Maximum experimental loads include over-all load factors of 2g, moments of 128,000 pound-feet, and maximum local pressures greater than 40 pounds per square inch. Experimental over-all loads are approximately one-half the design values, while local pressures are of the same order as or larger than pressures calculated from specifications for plating, stringer, floor, and frame design. The value of this comparison is limited, to some extent, by the moderate conditions of the test and by the necessary simplifying assumptions used in comparing the specifications with the experimental loads.

An improved wavelet neural network medical image segmentation algorithm with combined maximum entropy

NASA Astrophysics Data System (ADS)

Hu, Xiaoqian; Tao, Jinxu; Ye, Zhongfu; Qiu, Bensheng; Xu, Jinzhang

2018-05-01

In order to solve the problem of medical image segmentation, a wavelet neural network medical image segmentation algorithm based on combined maximum entropy criterion is proposed. Firstly, we use bee colony algorithm to optimize the network parameters of wavelet neural network, get the parameters of network structure, initial weights and threshold values, and so on, we can quickly converge to higher precision when training, and avoid to falling into relative extremum; then the optimal number of iterations is obtained by calculating the maximum entropy of the segmented image, so as to achieve the automatic and accurate segmentation effect. Medical image segmentation experiments show that the proposed algorithm can reduce sample training time effectively and improve convergence precision, and segmentation effect is more accurate and effective than traditional BP neural network (back propagation neural network : a multilayer feed forward neural network which trained according to the error backward propagation algorithm.

Maximum Relative Entropy of Coherence: An Operational Coherence Measure.

PubMed

Bu, Kaifeng; Singh, Uttam; Fei, Shao-Ming; Pati, Arun Kumar; Wu, Junde

2017-10-13

The operational characterization of quantum coherence is the cornerstone in the development of the resource theory of coherence. We introduce a new coherence quantifier based on maximum relative entropy. We prove that the maximum relative entropy of coherence is directly related to the maximum overlap with maximally coherent states under a particular class of operations, which provides an operational interpretation of the maximum relative entropy of coherence. Moreover, we show that, for any coherent state, there are examples of subchannel discrimination problems such that this coherent state allows for a higher probability of successfully discriminating subchannels than that of all incoherent states. This advantage of coherent states in subchannel discrimination can be exactly characterized by the maximum relative entropy of coherence. By introducing a suitable smooth maximum relative entropy of coherence, we prove that the smooth maximum relative entropy of coherence provides a lower bound of one-shot coherence cost, and the maximum relative entropy of coherence is equivalent to the relative entropy of coherence in the asymptotic limit. Similar to the maximum relative entropy of coherence, the minimum relative entropy of coherence has also been investigated. We show that the minimum relative entropy of coherence provides an upper bound of one-shot coherence distillation, and in the asymptotic limit the minimum relative entropy of coherence is equivalent to the relative entropy of coherence.

Effects of Age and Schooling on Intellectual Performance: Estimates Obtained from Analysis of Continuous Variation in Age and Length of Schooling

ERIC Educational Resources Information Center

Cliffordson, Christina; Gustafsson, Jan-Eric

2008-01-01

The effects of age and schooling on different aspects of intellectual performance, taking track of study into account, are investigated. The analyses were based on military enlistment test scores, obtained by 48,269 males, measuring Fluid ability (Gf), Crystallized intelligence (Gc), and General visualization (Gv) ability. A regression method,…

24 CFR 203.474 - Maximum claim period.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Maximum claim period. 203.474 Section 203.474 Housing and Urban Development Regulations Relating to Housing and Urban Development... SINGLE FAMILY MORTGAGE INSURANCE Contract Rights and Obligations Rehabilitation Loans § 203.474 Maximum...

40 CFR 35.265 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.265 Section 35.265 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE....265 Maximum federal share. The Regional Administrator may provide up to 60 percent of the approved...

33 CFR 401.3 - Maximum vessel dimensions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Maximum vessel dimensions. 401.3 Section 401.3 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.3 Maximum vessel dimensions...

24 CFR 220.820 - Maximum claim period.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Maximum claim period. 220.820 Section 220.820 Housing and Urban Development Regulations Relating to Housing and Urban Development... Contract Rights and Obligations-Projects Insured Project Improvement Loans § 220.820 Maximum claim period...

40 CFR 35.705 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.705 Section 35.705 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...) § 35.705 Maximum federal share. The Regional Administrator may provide Tribes and Intertribal Consortia...

40 CFR 35.295 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.295 Section 35.295 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Maximum federal share. The Regional Administrator may provide State agencies up to 50 percent of the...

Coefficient of performance and its bounds with the figure of merit for a general refrigerator

NASA Astrophysics Data System (ADS)

Long, Rui; Liu, Wei

2015-02-01

A general refrigerator model with non-isothermal processes is studied. The coefficient of performance (COP) and its bounds at maximum χ figure of merit are obtained and analyzed. This model accounts for different heat capacities during the heat transfer processes. So, different kinds of refrigerator cycles can be considered. Under the constant heat capacity condition, the upper bound of the COP is the Curzon-Ahlborn (CA) coefficient of performance and is independent of the time durations of the heat exchanging processes. With the maximum χ criterion, in the refrigerator cycles, such as the reversed Brayton refrigerator cycle, the reversed Otto refrigerator cycle and the reversed Atkinson refrigerator cycle, where the heat capacity in the heat absorbing process is not less than that in the heat releasing process, their COPs are bounded by the CA coefficient of performance; otherwise, such as for the reversed Diesel refrigerator cycle, its COP can exceed the CA coefficient of performance. Furthermore, the general refined upper and lower bounds have been proposed.

Maximum Frictional Charge Generation on Polymer Surfaces

NASA Astrophysics Data System (ADS)

Calle, Carlos; Groop, Ellen; Mantovani, James; Buehler, Martin

2001-03-01

The maximum amount of charge that a given surface area can hold is limited by the surrounding environmental conditions such as the atmospheric composition, pressure, humidity, and temperature. Above this charge density limit, the surface will discharge to the atmosphere or to a nearby conductive surface that is at a different electric potential. We have performed experiments using the MECA Electrometer, a flight instrument developed jointly by the Jet Propulsion Laboratory and NASA Kennedy Space Center to study the electrostatic properties of the Martian soil. The electrometer contains five types of polymers: fiberglass/epoxy, polycarbonate (Lexan), polytetraflouroethylene (Teflon), Rulon J, and polymethylmethacrylate (PMMA, Lucite). We repeatedly rubbed the polymers with another material until each polymer's charge saturation was determined. We will discuss the correlation of our data with the triboelectric series.

Calibration Modeling Methodology to Optimize Performance for Low Range Applications

NASA Technical Reports Server (NTRS)

McCollum, Raymond A.; Commo, Sean A.; Parker, Peter A.

2010-01-01

Calibration is a vital process in characterizing the performance of an instrument in an application environment and seeks to obtain acceptable accuracy over the entire design range. Often, project requirements specify a maximum total measurement uncertainty, expressed as a percent of full-scale. However in some applications, we seek to obtain enhanced performance at the low range, therefore expressing the accuracy as a percent of reading should be considered as a modeling strategy. For example, it is common to desire to use a force balance in multiple facilities or regimes, often well below its designed full-scale capacity. This paper presents a general statistical methodology for optimizing calibration mathematical models based on a percent of reading accuracy requirement, which has broad application in all types of transducer applications where low range performance is required. A case study illustrates the proposed methodology for the Mars Entry Atmospheric Data System that employs seven strain-gage based pressure transducers mounted on the heatshield of the Mars Science Laboratory mission.

PREAL: prediction of allergenic protein by maximum Relevance Minimum Redundancy (mRMR) feature selection

PubMed Central

2013-01-01

Background Assessment of potential allergenicity of protein is necessary whenever transgenic proteins are introduced into the food chain. Bioinformatics approaches in allergen prediction have evolved appreciably in recent years to increase sophistication and performance. However, what are the critical features for protein's allergenicity have been not fully investigated yet. Results We presented a more comprehensive model in 128 features space for allergenic proteins prediction by integrating various properties of proteins, such as biochemical and physicochemical properties, sequential features and subcellular locations. The overall accuracy in the cross-validation reached 93.42% to 100% with our new method. Maximum Relevance Minimum Redundancy (mRMR) method and Incremental Feature Selection (IFS) procedure were applied to obtain which features are essential for allergenicity. Results of the performance comparisons showed the superior of our method to the existing methods used widely. More importantly, it was observed that the features of subcellular locations and amino acid composition played major roles in determining the allergenicity of proteins, particularly extracellular/cell surface and vacuole of the subcellular locations for wheat and soybean. To facilitate the allergen prediction, we implemented our computational method in a web application, which can be available at http://gmobl.sjtu.edu.cn/PREAL/index.php. Conclusions Our new approach could improve the accuracy of allergen prediction. And the findings may provide novel insights for the mechanism of allergies. PMID:24565053

On the Maximum Storage Capacity of the Hopfield Model

PubMed Central

Folli, Viola; Leonetti, Marco; Ruocco, Giancarlo

2017-01-01

Recurrent neural networks (RNN) have traditionally been of great interest for their capacity to store memories. In past years, several works have been devoted to determine the maximum storage capacity of RNN, especially for the case of the Hopfield network, the most popular kind of RNN. Analyzing the thermodynamic limit of the statistical properties of the Hamiltonian corresponding to the Hopfield neural network, it has been shown in the literature that the retrieval errors diverge when the number of stored memory patterns (P) exceeds a fraction (≈ 14%) of the network size N. In this paper, we study the storage performance of a generalized Hopfield model, where the diagonal elements of the connection matrix are allowed to be different from zero. We investigate this model at finite N. We give an analytical expression for the number of retrieval errors and show that, by increasing the number of stored patterns over a certain threshold, the errors start to decrease and reach values below unit for P ≫ N. We demonstrate that the strongest trade-off between efficiency and effectiveness relies on the number of patterns (P) that are stored in the network by appropriately fixing the connection weights. When P≫N and the diagonal elements of the adjacency matrix are not forced to be zero, the optimal storage capacity is obtained with a number of stored memories much larger than previously reported. This theory paves the way to the design of RNN with high storage capacity and able to retrieve the desired pattern without distortions. PMID:28119595

Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics

PubMed Central

Bates, K. T.; Falkingham, P. L.

2012-01-01

Bite mechanics and feeding behaviour in Tyrannosaurus rex are controversial. Some contend that a modest bite mechanically limited T. rex to scavenging, while others argue that high bite forces facilitated a predatory mode of life. We use dynamic musculoskeletal models to simulate maximal biting in T. rex. Models predict that adult T. rex generated sustained bite forces of 35 000–57 000 N at a single posterior tooth, by far the highest bite forces estimated for any terrestrial animal. Scaling analyses suggest that adult T. rex had a strong bite for its body size, and that bite performance increased allometrically during ontogeny. Positive allometry in bite performance during growth may have facilitated an ontogenetic change in feeding behaviour in T. rex, associated with an expansion of prey range in adults to include the largest contemporaneous animals. PMID:22378742

Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics.

PubMed

Bates, K T; Falkingham, P L

2012-08-23

Bite mechanics and feeding behaviour in Tyrannosaurus rex are controversial. Some contend that a modest bite mechanically limited T. rex to scavenging, while others argue that high bite forces facilitated a predatory mode of life. We use dynamic musculoskeletal models to simulate maximal biting in T. rex. Models predict that adult T. rex generated sustained bite forces of 35 000-57 000 N at a single posterior tooth, by far the highest bite forces estimated for any terrestrial animal. Scaling analyses suggest that adult T. rex had a strong bite for its body size, and that bite performance increased allometrically during ontogeny. Positive allometry in bite performance during growth may have facilitated an ontogenetic change in feeding behaviour in T. rex, associated with an expansion of prey range in adults to include the largest contemporaneous animals.

Maximum-Likelihood Detection Of Noncoherent CPM

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Simon, Marvin K.

1993-01-01

Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.

Continuous-wave and passively Q-switched laser performance of Nd:(LaxGd1-x)3Ga5O12 crystal at 1062 nm CW and PQS laser performance of Nd:LaGGG crystal at 1062 nm

NASA Astrophysics Data System (ADS)

Yang, H.; Fu, X.-W.; Jia, Z.-T.; He, J.-L.; Yang, X.-Q.; Zhang, B.-T.; Wang, R.-H.; Liu, X.-M.; Hou, J.; Lou, F.; Wang, Z.-W.; Yang, Y.

2012-10-01

The performance of diode-pumped continuous-wave (CW) and passively Q-switched (PQS) Nd:(LaxGd1-x)3Ga5O12 lasers at 1062 nm were demonstrated for the first time to our knowledge. The highest CW output power of 9.9 W was obtained, corresponding to an optical-to-optical efficiency of 42.9%. For the passive Q-switching operation, when the output coupler of Toc = 27% was adopted, the maximum output power of 3.97 W was obtained by a Cr4+:YAG saturable absorber with the initial transmission of T0 = 89.9%.While at T0 = 81.4% and Toc = 27%, the output power of 2.83 W, with pulse width of 7.4 ns and the repetition rate of 13.87 kHz, was obtained, corresponding to the maximum peak power of 27.6 kW and single pulse energy of 0.2 mJ, respectively.

49 CFR 195.406 - Maximum operating pressure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for surge pressures and other variations from normal operations, no operator may operate a pipeline at a... 49 Transportation 3 2010-10-01 2010-10-01 false Maximum operating pressure. 195.406 Section 195...

49 CFR 195.406 - Maximum operating pressure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for surge pressures and other variations from normal operations, no operator may operate a pipeline at a... 49 Transportation 3 2012-10-01 2012-10-01 false Maximum operating pressure. 195.406 Section 195...

49 CFR 195.406 - Maximum operating pressure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for surge pressures and other variations from normal operations, no operator may operate a pipeline at a... 49 Transportation 3 2014-10-01 2014-10-01 false Maximum operating pressure. 195.406 Section 195...

49 CFR 195.406 - Maximum operating pressure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for surge pressures and other variations from normal operations, no operator may operate a pipeline at a... 49 Transportation 3 2011-10-01 2011-10-01 false Maximum operating pressure. 195.406 Section 195...

49 CFR 195.406 - Maximum operating pressure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for surge pressures and other variations from normal operations, no operator may operate a pipeline at a... 49 Transportation 3 2013-10-01 2013-10-01 false Maximum operating pressure. 195.406 Section 195...

40 CFR 35.235 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.235 Section 35.235 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...)(1)) § 35.235 Maximum federal share. The Regional Administrator may provide up to 100 percent of the...

40 CFR 35.315 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.315 Section 35.315 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... 28) § 35.315 Maximum federal share. The Regional Administrator may provide up to 75 percent of the...

40 CFR 35.215 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.215 Section 35.215 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...)) § 35.215 Maximum federal share. The Regional Administrator may provide up to 75 percent of the approved...

40 CFR 35.715 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.715 Section 35.715 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Monitoring (section 28) § 35.715 Maximum federal share. The Regional Administrator may provide up to 75...

29 CFR 4022.22 - Maximum guaranteeable benefit.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Maximum guaranteeable benefit. 4022.22 Section 4022.22 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION COVERAGE AND... Maximum guaranteeable benefit. Subject to section 4022B of ERISA and part 4022B of this chapter, benefits...

40 CFR 35.335 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.335 Section 35.335 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...)(2)) § 35.335 Maximum federal share. The Regional Administrator may provide up to 75 percent of the...

40 CFR 35.649 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.649 Section 35.649 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... and Training (section 23(a)(2)) § 35.649 Maximum federal share. The Regional Administrator may provide...

40 CFR 35.252 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.252 Section 35.252 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...)(1)) § 35.252 Maximum federal share. The Regional Administrator may provide up to 100 percent of the...

40 CFR 432.15 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... § 432.12(a)(1); and standards for ammonia (as N) are as follows: Performance Standards [NSPS] Regulatedparameter Maximum daily 1 Maximum monthly avg. 1 Ammonia (as N) 0.34 0.17 1 Pounds per 1000 lbs (or g/kg... ammonia (as N) apply: Performance Standards [NSPS] Regulatedparameter Maximum daily 1 Maximum monthly avg...

Efficiency at maximum power of a chemical engine.

PubMed

Hooyberghs, Hans; Cleuren, Bart; Salazar, Alberto; Indekeu, Joseph O; Van den Broeck, Christian

2013-10-07

A cyclically operating chemical engine is considered that converts chemical energy into mechanical work. The working fluid is a gas of finite-sized spherical particles interacting through elastic hard collisions. For a generic transport law for particle uptake and release, the efficiency at maximum power η(mp) [corrected] takes the form 1/2+cΔμ+O(Δμ(2)), with 1∕2 a universal constant and Δμ the chemical potential difference between the particle reservoirs. The linear coefficient c is zero for engines featuring a so-called left/right symmetry or particle fluxes that are antisymmetric in the applied chemical potential difference. Remarkably, the leading constant in η(mp) [corrected] is non-universal with respect to an exceptional modification of the transport law. For a nonlinear transport model, we obtain η(mp) = 1/(θ + 1) [corrected], with θ > 0 the power of Δμ in the transport equation.

Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum

USGS Publications Warehouse

Sluijs, A.; Schouten, S.; Pagani, M.; Woltering, M.; Brinkhuis, H.; Damste, J.S.S.; Dickens, G.R.; Huber, M.; Reichart, G.-J.; Stein, R.; Matthiessen, J.; Lourens, L.J.; Pedentchouk, N.; Backman, J.; Moran, K.; Clemens, S.; Cronin, T.; Eynaud, F.; Gattacceca, J.; Jakobsson, M.; Jordan, R.; Kaminski, M.; King, J.; Koc, N.; Martinez, N.C.; McInroy, D.; Moore, T.C.; O'Regan, M.; Onodera, J.; Palike, H.; Rea, B.; Rio, D.; Sakamoto, T.; Smith, D.C.; St John, K.E.K.; Suto, I.; Suzuki, N.; Takahashi, K.; Watanabe, M. E.; Yamamoto, M.

2006-01-01

The Palaeocene/Eocene thermal maximum, ???55 million years ago, was a brief period of widespread, extreme climatic warming, that was associated with massive atmospheric greenhouse gas input. Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition. We show that sea surface temperatures near the North Pole increased from ???18??C to over 23??C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. At the same time, sea level rose while anoxic and euxinic conditions developed in the ocean's bottom waters and photic zone, respectively. Increasing temperature and sea level match expectations based on palaeoclimate model simulations, but the absolute polar temperatures that we derive before, during and after the event are more than 10??C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms-perhaps polar stratospheric clouds or hurricane-induced ocean mixing-to amplify early Palaeogene polar temperatures. ?? 2006 Nature Publishing Group.

Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum.

PubMed

Sluijs, Appy; Schouten, Stefan; Pagani, Mark; Woltering, Martijn; Brinkhuis, Henk; Sinninghe Damsté, Jaap S; Dickens, Gerald R; Huber, Matthew; Reichart, Gert-Jan; Stein, Ruediger; Matthiessen, Jens; Lourens, Lucas J; Pedentchouk, Nikolai; Backman, Jan; Moran, Kathryn

2006-06-01

The Palaeocene/Eocene thermal maximum, approximately 55 million years ago, was a brief period of widespread, extreme climatic warming, that was associated with massive atmospheric greenhouse gas input. Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition. We show that sea surface temperatures near the North Pole increased from 18 degrees C to over 23 degrees C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. At the same time, sea level rose while anoxic and euxinic conditions developed in the ocean's bottom waters and photic zone, respectively. Increasing temperature and sea level match expectations based on palaeoclimate model simulations, but the absolute polar temperatures that we derive before, during and after the event are more than 10 degrees C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms--perhaps polar stratospheric clouds or hurricane-induced ocean mixing--to amplify early Palaeogene polar temperatures.

Hardware Implementation of Maximum Power Point Tracking for Thermoelectric Generators

NASA Astrophysics Data System (ADS)

Maganga, Othman; Phillip, Navneesh; Burnham, Keith J.; Montecucco, Andrea; Siviter, Jonathan; Knox, Andrew; Simpson, Kevin

2014-06-01

This work describes the practical implementation of two maximum power point tracking (MPPT) algorithms, namely those of perturb and observe, and extremum seeking control. The proprietary dSPACE system is used to perform hardware in the loop (HIL) simulation whereby the two control algorithms are implemented using the MATLAB/Simulink (Mathworks, Natick, MA) software environment in order to control a synchronous buck-boost converter connected to two commercial thermoelectric modules. The process of performing HIL simulation using dSPACE is discussed, and a comparison between experimental and simulated results is highlighted. The experimental results demonstrate the validity of the two MPPT algorithms, and in conclusion the benefits and limitations of real-time implementation of MPPT controllers using dSPACE are discussed.

Weighted Maximum-a-Posteriori Estimation in Tests Composed of Dichotomous and Polytomous Items

ERIC Educational Resources Information Center

Sun, Shan-Shan; Tao, Jian; Chang, Hua-Hua; Shi, Ning-Zhong