MFAHP: A novel method on the performance evaluation of the industrial wireless networked control system

NASA Astrophysics Data System (ADS)

Wu, Linqin; Xu, Sheng; Jiang, Dezhi

2015-12-01

Industrial wireless networked control system has been widely used, and how to evaluate the performance of the wireless network is of great significance. In this paper, considering the shortcoming of the existing performance evaluation methods, a comprehensive performance evaluation method of networks multi-indexes fuzzy analytic hierarchy process (MFAHP) combined with the fuzzy mathematics and the traditional analytic hierarchy process (AHP) is presented. The method can overcome that the performance evaluation is not comprehensive and subjective. Experiments show that the method can reflect the network performance of real condition. It has direct guiding role on protocol selection, network cabling, and node setting, and can meet the requirements of different occasions by modifying the underlying parameters.

MSFC Skylab thermal and environmental control system mission evaluation

NASA Technical Reports Server (NTRS)

Hopson, G. D.; Littles, J. W.; Patterson, W. C.

1974-01-01

An evaluation of the performance of the Skylab thermal and environmental control system is presented. Actual performance is compared to design and functional requirements and anomalies and discrepancies and their resolution are discussed. The thermal and environmental control systems performed their intended role. Based on the experience gained in design, development and flight, recommendations are provided which may be beneficial to future system designs.

Evaluation of the Anaheim Advanced Traffic Control System Field Operational Test : introduction and Task A : evaluation of SCOOT performance

DOT National Transportation Integrated Search

1999-03-01

This report provides an overview of both the Anaheim Advanced Traffic Control System Field Operations Test (FOT) and of the technical issues associated with the evaluation of SCOOT performance during the test. The primary objective of the FOT was to ...

Lateral directional requirements for a low L/D aeromaneuvering orbital transfer vehicle

NASA Technical Reports Server (NTRS)

Gamble, J. D.; Spratlin, K. M.; Skalecki, L. M.

1984-01-01

The lateral-directional aerodynamics and control requirements for a low L/D (0.3) aeromaneuvering orbital transfer vehicle are evaluated. A lateral directional RCS control concept that permits a linearized analysis is utilized to evaluate the effect of Dutch Roll frequency and damping on the atmospheric guidance and control performance. The bank rate and acceleration requirements for acceptable performance are defined and the sensitivity to a parameter similar to the lateral control departure parameter but involving the RCS jets is evaluated.

Crash Tests of Work Zone Traffic Control Devices

DOT National Transportation Integrated Search

1990-02-01

Full-scale vehicle crash tests evaluated performance of typical work zone traffic control devices. Modified test procedures and evaluation criteria from NCHRP Report 230 were used in 108 tests, providing significant insight into impact performance. P...

Flight tests for the assessment of task performance and control activity

NASA Technical Reports Server (NTRS)

Pausder, H. J.; Hummes, D.

1982-01-01

The tests were performed with the helicopters BO 105 and UH-1D. Closely connected with tactical demands the six test pilots' task was to minimize the time and the altitude over the obstacles. The data reduction yields statistical evaluation parameters describing the control activity of the pilots and the achieved task performance. The results are shown in form of evaluation diagrams. Additionally dolphin tests with varied control strategy were performed to get more insight into the influence of control techniques. From these test results recommendations can be derived to emphasize the direct force control and to reduce the collective to pitch crosscoupling for the dolphin.

Performance Evaluation of Reliable Multicast Protocol for Checkout and Launch Control Systems

NASA Technical Reports Server (NTRS)

Shu, Wei Wennie; Porter, John

2000-01-01

The overall objective of this project is to study reliability and performance of Real Time Critical Network (RTCN) for checkout and launch control systems (CLCS). The major tasks include reliability and performance evaluation of Reliable Multicast (RM) package and fault tolerance analysis and design of dual redundant network architecture.

Evaluation of control and display configurations for helicopter shipboard operations

NASA Technical Reports Server (NTRS)

Paulk, C. H., Jr.; Donley, S. T.; Hollis, M. K.

1983-01-01

A simulation evaluation of several approach and landing flight-control configurations and of two out-of-the-cockpit display devices (a head-up display and a helmet-mounted display) was performed for the task of landing a helicopter on a destroyer in adverse weather. The results indicated that the ship airwake turbulence was the most significant environmental variable affecting hover performance. In addition, to achieve adequate landing performance, attitude-command control compensation was required for the pilot regardless of the display used. For improved performance with reduced pilot effort, a velocity-command, position-hold control system was desired.

Sliding Mode Control of Real-Time PNU Vehicle Driving Simulator and Its Performance Evaluation

NASA Astrophysics Data System (ADS)

Lee, Min Cheol; Park, Min Kyu; Yoo, Wan Suk; Son, Kwon; Han, Myung Chul

This paper introduces an economical and effective full-scale driving simulator for study of human sensibility and development of new vehicle parts and its control. Real-time robust control to accurately reappear a various vehicle motion may be a difficult task because the motion platform is the nonlinear complex system. This study proposes the sliding mode controller with a perturbation compensator using observer-based fuzzy adaptive network (FAN). This control algorithm is designed to solve the chattering problem of a sliding mode control and to select the adequate fuzzy parameters of the perturbation compensator. For evaluating the trajectory control performance of the proposed approach, a tracking control of the developed simulator named PNUVDS is experimentally carried out. And then, the driving performance of the simulator is evaluated by using human perception and sensibility of some drivers in various driving conditions.

Display/control requirements for automated VTOL aircraft

NASA Technical Reports Server (NTRS)

Hoffman, W. C.; Kleinman, D. L.; Young, L. R.

1976-01-01

A systematic design methodology for pilot displays in advanced commercial VTOL aircraft was developed and refined. The analyst is provided with a step-by-step procedure for conducting conceptual display/control configurations evaluations for simultaneous monitoring and control pilot tasks. The approach consists of three phases: formulation of information requirements, configuration evaluation, and system selection. Both the monitoring and control performance models are based upon the optimal control model of the human operator. Extensions to the conventional optimal control model required in the display design methodology include explicit optimization of control/monitoring attention; simultaneous monitoring and control performance predictions; and indifference threshold effects. The methodology was applied to NASA's experimental CH-47 helicopter in support of the VALT program. The CH-47 application examined the system performance of six flight conditions. Four candidate configurations are suggested for evaluation in pilot-in-the-loop simulations and eventual flight tests.

Optimization and evaluation of a proportional derivative controller for planar arm movement.

PubMed

Jagodnik, Kathleen M; van den Bogert, Antonie J

2010-04-19

In most clinical applications of functional electrical stimulation (FES), the timing and amplitude of electrical stimuli have been controlled by open-loop pattern generators. The control of upper extremity reaching movements, however, will require feedback control to achieve the required precision. Here we present three controllers using proportional derivative (PD) feedback to stimulate six arm muscles, using two joint angle sensors. Controllers were first optimized and then evaluated on a computational arm model that includes musculoskeletal dynamics. Feedback gains were optimized by minimizing a weighted sum of position errors and muscle forces. Generalizability of the controllers was evaluated by performing movements for which the controller was not optimized, and robustness was tested via model simulations with randomly weakened muscles. Robustness was further evaluated by adding joint friction and doubling the arm mass. After optimization with a properly weighted cost function, all PD controllers performed fast, accurate, and robust reaching movements in simulation. Oscillatory behavior was seen after improper tuning. Performance improved slightly as the complexity of the feedback gain matrix increased. Copyright 2009 Elsevier Ltd. All rights reserved.

Optimization and evaluation of a proportional derivative controller for planar arm movement

PubMed Central

Jagodnik, Kathleen M.; van den Bogert, Antonie J.

2013-01-01

In most clinical applications of functional electrical stimulation (FES), the timing and amplitude of electrical stimuli have been controlled by open-loop pattern generators. The control of upper extremity reaching movements, however, will require feedback control to achieve the required precision. Here we present three controllers using proportional derivative (PD) feedback to stimulate six arm muscles, using two joint angle sensors. Controllers were first optimized and then evaluated on a computational arm model that includes musculoskeletal dynamics. Feedback gains were optimized by minimizing a weighted sum of position errors and muscle forces. Generalizability of the controllers was evaluated by performing movements for which the controller was not optimized, and robustness was tested via model simulations with randomly weakened muscles. Robustness was further evaluated by adding joint friction and doubling the arm mass. After optimization with a properly weighted cost function, all PD controllers performed fast, accurate, and robust reaching movements in simulation. Oscillatory behavior was seen after improper tuning. Performance improved slightly as the complexity of the feedback gain matrix increased. PMID:20097345

Design and evaluation of prosthetic shoulder controller

PubMed Central

Barton, Joseph E.; Sorkin, John D.

2015-01-01

We developed a 2-degree-of-freedom (DOF) shoulder position transducer (sensing shoulder protraction-retraction and elevation-depression) that can be used to control two of a powered prosthetic humerus' DOFs. We also developed an evaluation protocol based on Fitts' law to assess the performance of our device. The primary motivation for this work was to support development of powered prosthetic shoulder joints of a new generation of prosthetic arms for people with shoulder disarticulation and very high-level transhumeral amputation. We found that transducers that provided resistance to shoulder movement performed better than those providing no resistance. We also found that a position control scheme, where effector position is proportional to shoulder position, performed better than a velocity control scheme, where effector velocity is proportional to shoulder position. More generally, our transducer can be used to control motion along any two DOFs. It can also be used in a more general 4-DOF control scheme by sequentially controlling two DOFs at a time. The evaluation protocol has general applicability for researchers and practitioners. Researchers can employ it to compare different prosthesis designs and control schemes, while practitioners may find the evaluation protocol useful in evaluating and training people with amputation in the use of prostheses. PMID:25357185

Crew Exploration Vehicle Launch Abort Controller Performance Analysis

NASA Technical Reports Server (NTRS)

Sparks, Dean W., Jr.; Raney, David L.

2007-01-01

This paper covers the simulation and evaluation of a controller design for the Crew Module (CM) Launch Abort System (LAS), to measure its ability to meet the abort performance requirements. The controller used in this study is a hybrid design, including features developed by the Government and the Contractor. Testing is done using two separate 6-degree-of-freedom (DOF) computer simulation implementations of the LAS/CM throughout the ascent trajectory: 1) executing a series of abort simulations along a nominal trajectory for the nominal LAS/CM system; and 2) using a series of Monte Carlo runs with perturbed initial flight conditions and perturbed system parameters. The performance of the controller is evaluated against a set of criteria, which is based upon the current functional requirements of the LAS. Preliminary analysis indicates that the performance of the present controller meets (with the exception of a few cases) the evaluation criteria mentioned above.

Implementation and Evaluation of Multiple Adaptive Control Technologies for a Generic Transport Aircraft Simulation

NASA Technical Reports Server (NTRS)

Campbell, Stefan F.; Kaneshige, John T.; Nguyen, Nhan T.; Krishakumar, Kalmanje S.

2010-01-01

Presented here is the evaluation of multiple adaptive control technologies for a generic transport aircraft simulation. For this study, seven model reference adaptive control (MRAC) based technologies were considered. Each technology was integrated into an identical dynamic-inversion control architecture and tuned using a methodology based on metrics and specific design requirements. Simulation tests were then performed to evaluate each technology s sensitivity to time-delay, flight condition, model uncertainty, and artificially induced cross-coupling. The resulting robustness and performance characteristics were used to identify potential strengths, weaknesses, and integration challenges of the individual adaptive control technologies

Extended performance electric propulsion power processor design study. Volume 2: Technical summary

NASA Technical Reports Server (NTRS)

Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.

1977-01-01

Electric propulsion power processor technology has processed during the past decade to the point that it is considered ready for application. Several power processor design concepts were evaluated and compared. Emphasis was placed on a 30 cm ion thruster power processor with a beam power rating supply of 2.2KW to 10KW for the main propulsion power stage. Extension in power processor performance were defined and were designed in sufficient detail to determine efficiency, component weight, part count, reliability and thermal control. A detail design was performed on a microprocessor as the thyristor power processor controller. A reliability analysis was performed to evaluate the effect of the control electronics redesign. Preliminary electrical design, mechanical design and thermal analysis were performed on a 6KW power transformer for the beam supply. Bi-Mod mechanical, structural and thermal control configurations were evaluated for the power processor and preliminary estimates of mechanical weight were determined.

First results of the wind evaluation breadboard for ELT primary mirror design

NASA Astrophysics Data System (ADS)

Reyes García-Talavera, Marcos; Viera, Teodora; Núñez, Miguel

2010-07-01

The Wind Evaluation Breadboard (WEB) is a primary mirror and telescope simulator formed by seven aluminium segments, including position sensors, electromechanical support systems and support structures. WEB has been developed to evaluate technologies for primary mirror wavefront control and to evaluate the performance of the control of wind buffeting disturbance on ELT segmented mirrors. For this purpose WEB electro-mechanical set-up simulates the real operational constrains applied to large segmented mirrors. This paper describes the WEB assembly, integration and verification, the instrument characterisation and close loop control design, including the dynamical characterization of the instrument and the control architecture. The performance of the new technologies developed for position sensing, acting and controlling is evaluated. The integration of the instrument in the observatory and the results of the first experiments are summarised, with different wind conditions, elevation and azimuth angles of incidence. Conclusions are extracted with respect the wind rejection performance and the control strategy for an ELT. WEB has been designed and developed by IAC, ESO, ALTRAN and JUPASA, with the integration of subsystems of FOGALE and TNO.

Evaluation of Seismic Performance and Effectiveness of Multiple Slim-Type Damper System for Seismic Response Control of Building Structures

PubMed Central

Kim, David; Sung, Eun Hee; Park, Kwan-Soon; Park, Jaegyun

2014-01-01

This paper presents the evaluation of seismic performance and cost-effectiveness of a multiple slim-type damper system developed for the vibration control of earthquake excited buildings. The multiple slim-type damper (MSD) that consists of several small slim-type dampers and linkage units can control damping capacity easily by changing the number of small dampers. To evaluate the performance of the MSD, dynamic loading tests are performed with three slim-type dampers manufactured at a real scale. Numerical simulations are also carried out by nonlinear time history analysis with a ten-story earthquake excited building structure. The seismic performance and cost-effectiveness of the MSD system are investigated according to the various installation configurations of the MSD system. From the results of numerical simulation and cost-effectiveness evaluation, it is shown that combinations of the MSD systems can effectively improve the seismic performance of earthquake excited building structures. PMID:25301387

Real-time robustness evaluation of regression based myoelectric control against arm position change and donning/doffing.

PubMed

Hwang, Han-Jeong; Hahne, Janne Mathias; Müller, Klaus-Robert

2017-01-01

There are some practical factors, such as arm position change and donning/doffing, which prevent robust myoelectric control. The objective of this study is to precisely characterize the impacts of the two representative factors on myoelectric controllability in practical control situations, thereby providing useful references that can be potentially used to find better solutions for clinically reliable myoelectric control. To this end, a real-time target acquisition task was performed by fourteen subjects including one individual with congenital upper-limb deficiency, where the impacts of arm position change, donning/doffing and a combination of both factors on control performance was systematically evaluated. The changes in online performance were examined with seven different performance metrics to comprehensively evaluate various aspects of myoelectric controllability. As a result, arm position change significantly affects offline prediction accuracy, but not online control performance due to real-time feedback, thereby showing no significant correlation between offline and online performance. Donning/doffing was still problematic in online control conditions. It was further observed that no benefit was attained when using a control model trained with multiple position data in terms of arm position change, and the degree of electrode shift caused by donning/doffing was not severely associated with the degree of performance loss under practical conditions (around 1 cm electrode shift). Since this study is the first to concurrently investigate the impacts of arm position change and donning/doffing in practical myoelectric control situations, all findings of this study provide new insights into robust myoelectric control with respect to arm position change and donning/doffing.

Real-time robustness evaluation of regression based myoelectric control against arm position change and donning/doffing

PubMed Central

Hahne, Janne Mathias; Müller, Klaus-Robert

2017-01-01

There are some practical factors, such as arm position change and donning/doffing, which prevent robust myoelectric control. The objective of this study is to precisely characterize the impacts of the two representative factors on myoelectric controllability in practical control situations, thereby providing useful references that can be potentially used to find better solutions for clinically reliable myoelectric control. To this end, a real-time target acquisition task was performed by fourteen subjects including one individual with congenital upper-limb deficiency, where the impacts of arm position change, donning/doffing and a combination of both factors on control performance was systematically evaluated. The changes in online performance were examined with seven different performance metrics to comprehensively evaluate various aspects of myoelectric controllability. As a result, arm position change significantly affects offline prediction accuracy, but not online control performance due to real-time feedback, thereby showing no significant correlation between offline and online performance. Donning/doffing was still problematic in online control conditions. It was further observed that no benefit was attained when using a control model trained with multiple position data in terms of arm position change, and the degree of electrode shift caused by donning/doffing was not severely associated with the degree of performance loss under practical conditions (around 1 cm electrode shift). Since this study is the first to concurrently investigate the impacts of arm position change and donning/doffing in practical myoelectric control situations, all findings of this study provide new insights into robust myoelectric control with respect to arm position change and donning/doffing. PMID:29095846

Primary Health Care and tuberculosis: services evaluation.

PubMed

Wysocki, Anneliese Domingues; Ponce, Maria Amélia Zanon; Brunello, Maria Eugênia Firmino; Beraldo, Aline Ale; Vendramini, Silvia Helena Figueiredo; Scatena, Lúcia Marina; Ruffino, Antonio; Villa, Tereza Cristina Scatena

2017-01-01

In order to control tuberculosis, the Brazilian Ministry of Health recommends the decentralization of control actions directed to the Primary Health Care, and there are few studies on the performance of the Tuberculosis Control Program in decentralized contexts. To evaluate the performance of Primary Health Care services in tuberculosis treatment. This is an evaluative study with cross-sectional approach conducted in 2011. Two hundred and thirty-nine health professionals from Primary Health Care units were interviewed using a structured instrument based on the evaluation reference of the health services quality (structure - process - results). The performance of these services was analyzed applying techniques of descriptive statistics, validation, and construction of indicators and by determining the reduced variable "Z". The indicators "participation of professionals in tuberculosis patients' care" (structure) and "reference and counterreference" (process) had the best evaluations, whereas "professional training" (structure) and "external actions for tuberculosis control" (process) had the worst results. The decentralization of tuberculosis control actions has been taking place in a vertical manner in Primary Health Care. The challenge of controlling tuberculosis involves overcoming constraints related to the engagement, training, and turnover rates among health professionals, which is a coordination between services and monitoring of control actions in Primary Health Care.

Propulsion system-flight control integration-flight evaluation and technology transition

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Gilyard, Glenn B.; Myers, Lawrence P.

1990-01-01

Integration of propulsion and flight control systems and their optimization offering significant performance improvement are assessed. In particular, research programs conducted by NASA on flight control systems and propulsion system-flight control interactions on the YF-12 and F-15 aircraft are addressed; these programs have demonstrated increased thrust, reduced fuel consumption, increased engine life, and improved aircraft performance. Focus is placed on altitude control, speed-Mach control, integrated controller design, as well as flight control systems and digital electronic engine control. A highly integrated digital electronic control program is analyzed and compared with a performance seeking control program. It is shown that the flight evaluation and demonstration of these technologies have been a key part in the transition of the concepts to production and operational use on a timely basis.

Performance evaluation of haptic hand-controllers in a robot-assisted surgical system.

PubMed

Zareinia, Kourosh; Maddahi, Yaser; Ng, Canaan; Sepehri, Nariman; Sutherland, Garnette R

2015-12-01

This paper presents the experimental evaluation of three commercially available haptic hand-controllers to evaluate which was more suitable to the participants. Two surgeons and seven engineers performed two peg-in-hole tasks with different levels of difficulty. Each operator guided the end-effector of a Kuka manipulator that held surgical forceps and was equipped with a surgical microscope. Sigma 7, HD(2) and PHANToM Premium 3.0 hand-controllers were compared. Ten measures were adopted to evaluate operators' performances with respect to effort, speed and accuracy in completing a task, operator improvement during the tests, and the force applied by each haptic device. The best performance was observed with the Premium 3.0; the hand-piece was able to be held in a similar way to that used by surgeons to hold conventional tools. Hand-controllers with a linkage structure similar to the human upper extremity take advantage of the inherent human brain connectome, resulting in improved surgeon performance during robotic-assisted surgery. Copyright © 2015 John Wiley & Sons, Ltd.

Human performance evaluation in dual-axis critical task tracking

NASA Technical Reports Server (NTRS)

Ritchie, M. L.; Nataraj, N. S.

1975-01-01

A dual axis tracking using a multiloop critical task was set up to evaluate human performance. The effects of control stick variation and display formats are evaluated. A secondary loading was used to measure the degradation in tracking performance.

Impact of Motivation on Cognitive Control in the Context of Vigilance Lowering: An ERP Study

ERIC Educational Resources Information Center

Bonnefond, Anne; Doignon-Camus, Nadege; Hoeft, Alain; Dufour, Andre

2011-01-01

We assessed the effects of time-on-task on cognitive control expressed by the CRN/Nc and the extent to which motivation modulates this relationship. We utilized two groups of participants, who were told that their performance would (evaluation condition) or would not (control condition) be evaluated online. Both groups performed a version of the…

Performance and evaluation of real-time multicomputer control systems

NASA Technical Reports Server (NTRS)

Shin, K. G.

1983-01-01

New performance measures, detailed examples, modeling of error detection process, performance evaluation of rollback recovery methods, experiments on FTMP, and optimal size of an NMR cluster are discussed.

The Researching on Evaluation of Automatic Voltage Control Based on Improved Zoning Methodology

NASA Astrophysics Data System (ADS)

Xiao-jun, ZHU; Ang, FU; Guang-de, DONG; Rui-miao, WANG; De-fen, ZHU

2018-03-01

According to the present serious phenomenon of increasing size and structure of power system, hierarchically structured automatic voltage control(AVC) has been the researching spot. In the paper, the reduced control model is built and the adaptive reduced control model is researched to improve the voltage control effect. The theories of HCSD, HCVS, SKC and FCM are introduced and the effect on coordinated voltage regulation caused by different zoning methodologies is also researched. The generic framework for evaluating performance of coordinated voltage regulation is built. Finally, the IEEE-96 stsyem is used to divide the network. The 2383-bus Polish system is built to verify that the selection of a zoning methodology affects not only the coordinated voltage regulation operation, but also its robustness to erroneous data and proposes a comprehensive generic framework for evaluating its performance. The New England 39-bus network is used to verify the adaptive reduced control models’ performance.

Development and testing of controller performance evaluation methodology for multi-input/multi-output digital control systems

NASA Technical Reports Server (NTRS)

Pototzky, Anthony; Wieseman, Carol; Hoadley, Sherwood Tiffany; Mukhopadhyay, Vivek

1991-01-01

Described here is the development and implementation of on-line, near real time controller performance evaluation (CPE) methods capability. Briefly discussed are the structure of data flow, the signal processing methods used to process the data, and the software developed to generate the transfer functions. This methodology is generic in nature and can be used in any type of multi-input/multi-output (MIMO) digital controller application, including digital flight control systems, digitally controlled spacecraft structures, and actively controlled wind tunnel models. Results of applying the CPE methodology to evaluate (in near real time) MIMO digital flutter suppression systems being tested on the Rockwell Active Flexible Wing (AFW) wind tunnel model are presented to demonstrate the CPE capability.

Motivation in vigilance - Effects of self-evaluation and experimenter-controlled feedback.

NASA Technical Reports Server (NTRS)

Warm, J. S.; Kanfer, F. H.; Kuwada, S.; Clark, J. L.

1972-01-01

Vigilance experiments have been performed to study the relative efficiency of feedback operations in enhancing vigilance performance. Two feedback operations were compared - i.e., experimenter-controlled feedback in the form of knowledge of results (KR) regarding response times to signal detections, and subject-controlled feedback in the form of self-evaluation (SE) of response times to signal detections. The subjects responded to the aperiodic offset of a visual signal during a 1-hr vigil. Both feedback operations were found to enhance performance efficiency: subjects in the KR and SE conditions had faster response times than controls receiving no evaluative feedback. Moreover, the data of the KR and SE groups did not differ significantly from each other. The results are discussed in terms of the hypothesis that self-evaluation is a critical factor underlying the incentive value of KR in vigilance tasks.

Neural-genetic synthesis for state-space controllers based on linear quadratic regulator design for eigenstructure assignment.

PubMed

da Fonseca Neto, João Viana; Abreu, Ivanildo Silva; da Silva, Fábio Nogueira

2010-04-01

Toward the synthesis of state-space controllers, a neural-genetic model based on the linear quadratic regulator design for the eigenstructure assignment of multivariable dynamic systems is presented. The neural-genetic model represents a fusion of a genetic algorithm and a recurrent neural network (RNN) to perform the selection of the weighting matrices and the algebraic Riccati equation solution, respectively. A fourth-order electric circuit model is used to evaluate the convergence of the computational intelligence paradigms and the control design method performance. The genetic search convergence evaluation is performed in terms of the fitness function statistics and the RNN convergence, which is evaluated by landscapes of the energy and norm, as a function of the parameter deviations. The control problem solution is evaluated in the time and frequency domains by the impulse response, singular values, and modal analysis.

Evaluation of control strategies using an oxidation ditch benchmark.

PubMed

Abusam, A; Keesman, K J; Spanjers, H; van, Straten G; Meinema, K

2002-01-01

This paper presents validation and implementation results of a benchmark developed for a specific full-scale oxidation ditch wastewater treatment plant. A benchmark is a standard simulation procedure that can be used as a tool in evaluating various control strategies proposed for wastewater treatment plants. It is based on model and performance criteria development. Testing of this benchmark, by comparing benchmark predictions to real measurements of the electrical energy consumptions and amounts of disposed sludge for a specific oxidation ditch WWTP, has shown that it can (reasonably) be used for evaluating the performance of this WWTP. Subsequently, the validated benchmark was then used in evaluating some basic and advanced control strategies. Some of the interesting results obtained are the following: (i) influent flow splitting ratio, between the first and the fourth aerated compartments of the ditch, has no significant effect on the TN concentrations in the effluent, and (ii) for evaluation of long-term control strategies, future benchmarks need to be able to assess settlers' performance.

Light Water Reactor Sustainability Program Operator Performance Metrics for Control Room Modernization: A Practical Guide for Early Design Evaluation

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

Ronald Boring; Roger Lew; Thomas Ulrich

2014-03-01

As control rooms are modernized with new digital systems at nuclear power plants, it is necessary to evaluate the operator performance using these systems as part of a verification and validation process. There are no standard, predefined metrics available for assessing what is satisfactory operator interaction with new systems, especially during the early design stages of a new system. This report identifies the process and metrics for evaluating human system interfaces as part of control room modernization. The report includes background information on design and evaluation, a thorough discussion of human performance measures, and a practical example of how themore » process and metrics have been used as part of a turbine control system upgrade during the formative stages of design. The process and metrics are geared toward generalizability to other applications and serve as a template for utilities undertaking their own control room modernization activities.« less

The relationship of post-event processing to self-evaluation of performance in social anxiety.

PubMed

Brozovich, Faith; Heimberg, Richard G

2011-06-01

Socially anxious and control participants engaged in a social interaction with a confederate and then wrote about themselves or the other person (i.e., self-focused post-event processing [SF-PEP] vs. other-focused post-event processing [OF-PEP]) and completed several questionnaires. One week later, participants completed measures concerning their evaluation of their performance in the social interaction and the degree to which they engaged in post-event processing (PEP) during the week. Socially anxious individuals evaluated their performance in the social interaction more poorly than control participants, both immediately after and 1 week later. Socially anxious individuals assigned to the SF-PEP condition displayed fewer positive feelings about their performance compared to the socially anxious individuals in the OF-PEP condition as well as controls in either condition. Also, the trait tendency to engage in PEP moderated the effect of social anxiety on participants' evaluation of their performance in the interaction, such that high socially anxious individuals with high trait PEP scores evaluated themselves in the interaction more negatively at the later assessment. These results suggest that PEP and other self-evaluative processes may perpetuate the cycle of social anxiety. Copyright © 2011. Published by Elsevier Ltd.

Improved rate control for electron-beam evaporation and evaluation of optical performance improvements.

PubMed

Gevelber, Michael; Xu, Bing; Smith, Douglas

2006-03-01

A new deposition-rate-control and electron-beam-gun (e-gun) strategy was developed that significantly reduces the growth-rate variations for e-beam-deposited SiO2 coatings. The resulting improvements in optical performance are evaluated for multilayer bandpass filters. The adverse effect of uneven silica-source depletion on coating spectral performances during long deposition runs is discussed.

Evaluation of selected auditory tests in school-age children suspected of auditory processing disorders.

PubMed

Vanniasegaram, Iyngaram; Cohen, Mazal; Rosen, Stuart

2004-12-01

To compare the auditory function of normal-hearing children attending mainstream schools who were referred for an auditory evaluation because of listening/hearing problems (suspected auditory processing disorders [susAPD]) with that of normal-hearing control children. Sixty-five children with a normal standard audiometric evaluation, ages 6-14 yr (32 of whom were referred for susAPD, with the rest age-matched control children), completed a battery of four auditory tests: a dichotic test of competing sentences; a simple discrimination of short tone pairs differing in fundamental frequency at varying interstimulus intervals (TDT); a discrimination task using consonant cluster minimal pairs of real words (CCMP), and an adaptive threshold task for detecting a brief tone presented either simultaneously with a masker (simultaneous masking) or immediately preceding it (backward masking). Regression analyses, including age as a covariate, were performed to determine the extent to which the performance of the two groups differed on each task. Age-corrected z-scores were calculated to evaluate the effectiveness of the complete battery in discriminating the groups. The performance of the susAPD group was significantly poorer than the control group on all but the masking tasks, which failed to differentiate the two groups. The CCMP discriminated the groups most effectively, as it yielded the lowest number of control children with abnormal scores, and performance in both groups was independent of age. By contrast, the proportion of control children who performed poorly on the competing sentences test was unacceptably high. Together, the CCMP (verbal) and TDT (nonverbal) tasks detected impaired listening skills in 56% of the children who were referred to the clinic, compared with 6% of the control children. Performance on the two tasks was not correlated. Two of the four tests evaluated, the CCMP and TDT, proved effective in differentiating the two groups of children of this study. The application of both tests increased the proportion of susAPD children who performed poorly compared with the application of each test alone, while reducing the proportion of control subjects who performed poorly. The findings highlight the importance of carrying out a complete auditory evaluation in children referred for medical attention, even if their standard audiometric evaluation is unremarkable.

Flight Evaluation of an Aircraft with Side and Center Stick Controllers and Rate-Limited Ailerons

NASA Technical Reports Server (NTRS)

Deppe, P. R.; Chalk, C. R.; Shafer, M. F.

1996-01-01

As part of an ongoing government and industry effort to study the flying qualities of aircraft with rate-limited control surface actuators, two studies were previously flown to examine an algorithm developed to reduce the tendency for pilot-induced oscillation when rate limiting occurs. This algorithm, when working properly, greatly improved the performance of the aircraft in the first study. In the second study, however, the algorithm did not initially offer as much improvement. The differences between the two studies caused concern. The study detailed in this paper was performed to determine whether the performance of the algorithm was affected by the characteristics of the cockpit controllers. Time delay and flight control system noise were also briefly evaluated. An in-flight simulator, the Calspan Learjet 25, was programmed with a low roll actuator rate limit, and the algorithm was programmed into the flight control system. Side- and center-stick controllers, force and position command signals, a rate-limited feel system, a low-frequency feel system, and a feel system damper were evaluated. The flight program consisted of four flights and 38 evaluations of test configurations. Performance of the algorithm was determined to be unaffected by using side- or center-stick controllers or force or position command signals. The rate-limited feel system performed as well as the rate-limiting algorithm but was disliked by the pilots. The low-frequency feel system and the feel system damper were ineffective. Time delay and noise were determined to degrade the performance of the algorithm.

40 CFR Appendix A to Subpart Ll of... - Applicability of General Provisions

Code of Federal Regulations, 2010 CFR

2010-07-01

... not require CMS or CMS performance evaluation. 63.8(e) Performance evaluation for CMS No 63.9(b)(1)-(5... evaluations No Subpart LL does not require performance evaluation for CMS. 63.11(a)-(b) Control device... Appendix A to Subpart LL of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

Management systems research study

NASA Technical Reports Server (NTRS)

Bruno, A. V.

1975-01-01

The development of a Monte Carlo simulation of procurement activities at the NASA Ames Research Center is described. Data cover: simulation of the procurement cycle, construction of a performance evaluation model, examination of employee development, procedures and review of evaluation criteria for divisional and individual performance evaluation. Determination of the influences and apparent impact of contract type and structure and development of a management control system for planning and controlling manpower requirements.

Evaluating Cross-Cutting Approaches to Chronic Disease Prevention and Management: Developing a Comprehensive Evaluation

PubMed Central

Jernigan, Jan; Barnes, Seraphine Pitt; Shea, Pat; Davis, Rachel; Rutledge, Stephanie

2017-01-01

We provide an overview of the comprehensive evaluation of State Public Health Actions to Prevent and Control Diabetes, Heart Disease, Obesity and Associated Risk Factors and Promote School Health (State Public Health Actions). State Public Health Actions is a program funded by the Centers for Disease Control and Prevention to support the statewide implementation of cross-cutting approaches to promote health and prevent and control chronic diseases. The evaluation addresses the relevance, quality, and impact of the program by using 4 components: a national evaluation, performance measures, state evaluations, and evaluation technical assistance to states. Challenges of the evaluation included assessing the extent to which the program contributed to changes in the outcomes of interest and the variability in the states’ capacity to conduct evaluations and track performance measures. Given the investment in implementing collaborative approaches at both the state and national level, achieving meaningful findings from the evaluation is critical. PMID:29215974

Remote control circuit breaker evaluation testing. [for space shuttles

NASA Technical Reports Server (NTRS)

Bemko, L. M.

1974-01-01

Engineering evaluation tests were performed on several models/types of remote control circuit breakers marketed in an attempt to gain some insight into their potential suitability for use on the space shuttle vehicle. Tests included the measurement of several electrical and operational performance parameters under laboratory ambient, space simulation, acceleration and vibration environmental conditions.

A comparison of control strategies for wave energy converters

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

Coe, Ryan G.; Bacelli, Giorgio; Wilson, David G.

In this study, we employ a numerical model to compare the performance of a number of wave energy converter control strategies. The controllers selected for evaluation span a wide range in their requirements for implementation. Each control strategy is evaluated using a single numerical model with a set of sea states to represent a deployment site off the coast of Newport, OR. A number of metrics, ranging from power absorption to kinematics, are employed to provide a comparison of each control strategy’s performance that accounts for both relative benefits and costs. The results show a wide range of performances frommore » the different controllers and highlight the need for a holistic design approach which considers control design as a parallel component within the larger process WEC design.« less

A comparison of control strategies for wave energy converters

DOE PAGES

Coe, Ryan G.; Bacelli, Giorgio; Wilson, David G.; ...

2017-11-15

In this study, we employ a numerical model to compare the performance of a number of wave energy converter control strategies. The controllers selected for evaluation span a wide range in their requirements for implementation. Each control strategy is evaluated using a single numerical model with a set of sea states to represent a deployment site off the coast of Newport, OR. A number of metrics, ranging from power absorption to kinematics, are employed to provide a comparison of each control strategy’s performance that accounts for both relative benefits and costs. The results show a wide range of performances frommore » the different controllers and highlight the need for a holistic design approach which considers control design as a parallel component within the larger process WEC design.« less

Trajectory tracking in quadrotor platform by using PD controller and LQR control approach

NASA Astrophysics Data System (ADS)

Islam, Maidul; Okasha, Mohamed; Idres, Moumen Mohammad

2017-11-01

The purpose of the paper is to discuss a comparative evaluation of performance of two different controllers i.e. Proportional-Derivative Controller (PD) and Linear Quadratic Regulation (LQR) in Quadrotor dynamic system that is under-actuated with high nonlinearity. As only four states can be controlled at the same time in the Quadrotor, the trajectories are designed on the basis of the four states whereas three dimensional position and rotation along an axis, known as yaw movement are considered. In this work, both the PD controller and LQR control approach are used for Quadrotor nonlinear model to track the trajectories. LQR control approach for nonlinear model is designed on the basis of a linear model of the Quadrotor because the performance of linear model and nonlinear model around certain nominal point is almost similar. Simulink and MATLAB software is used to design the controllers and to evaluate the performance of both the controllers.

Real-time performance assessment and adaptive control for a water chiller unit in an HVAC system

NASA Astrophysics Data System (ADS)

Bai, Jianbo; Li, Yang; Chen, Jianhao

2018-02-01

The paper proposes an adaptive control method for a water chiller unit in a HVAC system. Based on the minimum variance evaluation, the adaptive control method was used to realize better control of the water chiller unit. To verify the performance of the adaptive control method, the proposed method was compared with an a conventional PID controller, the simulation results showed that adaptive control method had superior control performance to that of the conventional PID controller.

Statistical Process Control: A Quality Tool for a Venous Thromboembolic Disease Registry.

PubMed

Posadas-Martinez, Maria Lourdes; Rojas, Liliana Paloma; Vazquez, Fernando Javier; De Quiros, Fernan Bernaldo; Waisman, Gabriel Dario; Giunta, Diego Hernan

2016-01-01

We aim to describe Statistical Control Process as a quality tool for the Institutional Registry of Venous Thromboembolic Disease (IRTD), a registry developed in a community-care tertiary hospital in Buenos Aires, Argentina. The IRTD is a prospective cohort. The process of data acquisition began with the creation of a computerized alert generated whenever physicians requested imaging or laboratory study to diagnose venous thromboembolism, which defined eligible patients. The process then followed a structured methodology for patient's inclusion, evaluation, and posterior data entry. To control this process, process performance indicators were designed to be measured monthly. These included the number of eligible patients, the number of included patients, median time to patient's evaluation, and percentage of patients lost to evaluation. Control charts were graphed for each indicator. The registry was evaluated in 93 months, where 25,757 patients were reported and 6,798 patients met inclusion criteria. The median time to evaluation was 20 hours (SD, 12) and 7.7% of the total was lost to evaluation. Each indicator presented trends over time, caused by structural changes and improvement cycles, and therefore the central limit suffered inflexions. Statistical process control through process performance indicators allowed us to control the performance of the registry over time to detect systematic problems. We postulate that this approach could be reproduced for other clinical registries.

Large-scale performance and design for construction activity erosion control best management practices.

PubMed

Faucette, L B; Scholl, B; Beighley, R E; Governo, J

2009-01-01

The National Pollutant Discharge Elimination System (NPDES) Phase II requires construction activities to have erosion and sediment control best management practices (BMPs) designed and installed for site storm water management. Although BMPs are specified on storm water pollution prevention plans (SWPPPs) as part of the construction general permit (GP), there is little evidence in the research literature as to how BMPs perform or should be designed. The objectives of this study were to: (i) comparatively evaluate the performance of common construction activity erosion control BMPs under a standardized test method, (ii) evaluate the performance of compost erosion control blanket thickness, (iii) evaluate the performance of compost erosion control blankets (CECBs) on a variety of slope angles, and (iv) determine Universal Soil Loss Equation (USLE) cover management factors (C factors) for these BMPs to assist site designers and engineers. Twenty-three erosion control BMPs were evaluated using American Society of Testing and Materials (ASTM) D-6459, standard test method for determination of ECB performance in protecting hill slopes from rainfall induced erosion, on 4:1 (H:V), 3:1, and 2:1 slopes. Soil loss reduction for treatments exposed to 5 cm of rainfall on a 2:1 slope ranged from-7 to 99%. For rainfall exposure of 10 cm, treatment soil loss reduction ranged from 8 to 99%. The 2.5 and 5 cm CECBs significantly reduced erosion on slopes up to 2:1, while CECBs < 2.5 cm are not recommended on slopes >or= 4:1 when rainfall totals reach 5 cm. Based on the soil loss results, USLE C factors ranged from 0.01 to 0.9. These performance and design criteria should aid site planners and designers in decision-making processes.

Evaluation of an Outer Loop Retrofit Architecture for Intelligent Turbofan Engine Thrust Control

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Sowers, T. Shane

2006-01-01

The thrust control capability of a retrofit architecture for intelligent turbofan engine control and diagnostics is evaluated. The focus of the study is on the portion of the hierarchical architecture that performs thrust estimation and outer loop thrust control. The inner loop controls fan speed so the outer loop automatically adjusts the engine's fan speed command to maintain thrust at the desired level, based on pilot input, even as the engine deteriorates with use. The thrust estimation accuracy is assessed under nominal and deteriorated conditions at multiple operating points, and the closed loop thrust control performance is studied, all in a complex real-time nonlinear turbofan engine simulation test bed. The estimation capability, thrust response, and robustness to uncertainty in the form of engine degradation are evaluated.

Advanced controls for airbreathing engines, volume 3: Allison gas turbine

NASA Technical Reports Server (NTRS)

Bough, R. M.

1993-01-01

The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for airbreathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two-phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 3 of these reports describes the studies performed by the Allison Gas Turbine Division.

Advanced control for airbreathing engines, volume 1: Pratt and Whitney

NASA Technical Reports Server (NTRS)

Ralph, J. A.

1993-01-01

The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 1 of these reports describes the studies performed by Pratt & Whitney.

Advanced control for airbreathing engines, volume 2: General Electric aircraft engines

NASA Technical Reports Server (NTRS)

Bansal, Indar

1993-01-01

The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 2 of these reports describes the studies performed by GE Aircraft Engines.

Robust tuning of robot control systems

NASA Technical Reports Server (NTRS)

Minis, I.; Uebel, M.

1992-01-01

The computed torque control problem is examined for a robot arm with flexible, geared, joint drive systems which are typical in many industrial robots. The standard computed torque algorithm is not directly applicable to this class of manipulators because of the dynamics introduced by the joint drive system. The proposed approach to computed torque control combines a computed torque algorithm with torque controller at each joint. Three such control schemes are proposed. The first scheme uses the joint torque control system currently implemented on the robot arm and a novel form of the computed torque algorithm. The other two use the standard computed torque algorithm and a novel model following torque control system based on model following techniques. Standard tasks and performance indices are used to evaluate the performance of the controllers. Both numerical simulations and experiments are used in evaluation. The study shows that all three proposed systems lead to improved tracking performance over a conventional PD controller.

Evaluating Environmental Effects of Dredged Material Management Alternatives - A Technical Framework. Revision

DTIC Science & Technology

2004-05-01

Significant Impact HELPQ - Hydrologic Evaluation of Leachate Production and Quality HELP - Hydrologic Evaluation of Landfill Performance LDC...BIOASSAY SURFACE RUNOFF CONTROLS • PONDING • TREATMENT • OTHERS (5.3.6) AND EVALUATE AND /OR GROUNDWATER /OR LEACHATE • • • LEACHATE TESTING... LEACHATE CONTROLS COVERS LINERS TREATMENT PLANT BIOASSAY PLANT UPTAKE CONTROLS • COVERS • SELECTIVE VEGETATION (5.1) (5.2) (5.3

Performance and control study of a low-pressure-ratio turbojet engine for a drone aircraft

NASA Technical Reports Server (NTRS)

Seldner, K.; Geyser, L. C.; Gold, H.; Walker, D.; Burgner, G.

1972-01-01

The results of analog and digital computer studies of a low-pressure-ratio turbojet engine system for use in a drone vehicle are presented. The turbojet engine consists of a four-stage axial compressor, single-stage turbine, and a fixed area exhaust nozzle. Three simplified fuel schedules and a generalized parameter fuel control for the engine system are presented and evaluated. The evaluation is based on the performance of each schedule or control during engine acceleration from a windmill start at Mach 0.8 and 6100 meters to 100 percent corrected speed. It was found that, because of the higher acceleration margin permitted by the control, the generalized parameter control exhibited the best dynamic performance.

POCO-MOEA: Using Evolutionary Algorithms to Solve the Controller Placement Problem

DTIC Science & Technology

2016-03-24

to gather data on POCO-MOEA performance to a series of iv model networks. The algorithm’s behavior is then evaluated and compared to ex- haustive... evaluation of a third heuristic based on a Multi 3 Objective Evolutionary Algorithm (MOEA). This heuristic is modeled after one of the most well known MOEAs...researchers to extend into more realistic evaluations of the performance characteristics of SDN controllers, such as the use of simulators or live

Performance of an Automated-Mixed-Traffic-Vehicle /AMTV/ System. [urban people mover

NASA Technical Reports Server (NTRS)

Peng, T. K. C.; Chon, K.

1978-01-01

This study analyzes the operation and evaluates the expected performance of a proposed automatic guideway transit system which uses low-speed Automated Mixed Traffic Vehicles (AMTV's). Vehicle scheduling and headway control policies are evaluated with a transit system simulation model. The effect of mixed-traffic interference on the average vehicle speed is examined with a vehicle-pedestrian interface model. Control parameters regulating vehicle speed are evaluated for safe stopping and passenger comfort.

Flight evaluation results for a digital electronic engine control in an F-15 airplane

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Myers, L. P.; Walsh, K. R.

1983-01-01

A digital electronic engine control (DEEC) system on an F100 engine in an F-15 airplane was evaluated in flight. Thirty flights were flown in a four-phase program from June 1981 to February 1983. Significant improvements in the operability and performance of the F100 engine were developed as a result of the flight evaluation: the augmentor envelope was increased by 15,000 ft, the airstart envelope was improved by 75 knots, and the need to periodically trim the engine was eliminated. The hydromechanical backup control performance was evaluated and was found to be satisfactory. Two system failures were encountered in the test program; both were detected and accommodated successfully. No transfers to the backup control system were required, and no automatic transfers occurred. As a result of the successful DEEC flight evaluation, the DEEC system has entered the full-scale development phase.

Evaluation of the External RNA Controls Consortium (ERCC) reference material using a modified Latin square design.

PubMed

Pine, P Scott; Munro, Sarah A; Parsons, Jerod R; McDaniel, Jennifer; Lucas, Anne Bergstrom; Lozach, Jean; Myers, Timothy G; Su, Qin; Jacobs-Helber, Sarah M; Salit, Marc

2016-06-24

Highly multiplexed assays for quantitation of RNA transcripts are being used in many areas of biology and medicine. Using data generated by these transcriptomic assays requires measurement assurance with appropriate controls. Methods to prototype and evaluate multiple RNA controls were developed as part of the External RNA Controls Consortium (ERCC) assessment process. These approaches included a modified Latin square design to provide a broad dynamic range of relative abundance with known differences between four complex pools of ERCC RNA transcripts spiked into a human liver total RNA background. ERCC pools were analyzed on four different microarray platforms: Agilent 1- and 2-color, Illumina bead, and NIAID lab-made spotted microarrays; and two different second-generation sequencing platforms: the Life Technologies 5500xl and the Illumina HiSeq 2500. Individual ERCC controls were assessed for reproducible performance in signal response to concentration among the platforms. Most demonstrated linear behavior if they were not located near one of the extremes of the dynamic range. Performance issues with any individual ERCC transcript could be attributed to detection limitations, platform-specific target probe issues, or potential mixing errors. Collectively, these pools of spike-in RNA controls were evaluated for suitability as surrogates for endogenous transcripts to interrogate the performance of the RNA measurement process of each platform. The controls were useful for establishing the dynamic range of the assay, as well as delineating the useable region of that range where differential expression measurements, expressed as ratios, would be expected to be accurate. The modified Latin square design presented here uses a composite testing scheme for the evaluation of multiple performance characteristics: linear performance of individual controls, signal response within dynamic range pools of controls, and ratio detection between pairs of dynamic range pools. This compact design provides an economical sample format for the evaluation of multiple external RNA controls within a single experiment per platform. These results indicate that well-designed pools of RNA controls, spiked into samples, provide measurement assurance for endogenous gene expression studies.

On the use of controls for subsonic transport performance improvement: Overview and future directions

NASA Technical Reports Server (NTRS)

Gilyard, Glenn; Espana, Martin

1994-01-01

Increasing competition among airline manufacturers and operators has highlighted the issue of aircraft efficiency. Fewer aircraft orders have led to an all-out efficiency improvement effort among the manufacturers to maintain if not increase their share of the shrinking number of aircraft sales. Aircraft efficiency is important in airline profitability and is key if fuel prices increase from their current low. In a continuing effort to improve aircraft efficiency and develop an optimal performance technology base, NASA Dryden Flight Research Center developed and flight tested an adaptive performance seeking control system to optimize the quasi-steady-state performance of the F-15 aircraft. The demonstrated technology is equally applicable to transport aircraft although with less improvement. NASA Dryden, in transitioning this technology to transport aircraft, is specifically exploring the feasibility of applying adaptive optimal control techniques to performance optimization of redundant control effectors. A simulation evaluation of a preliminary control law optimizes wing-aileron camber for minimum net aircraft drag. Two submodes are evaluated: one to minimize fuel and the other to maximize velocity. This paper covers the status of performance optimization of the current fleet of subsonic transports. Available integrated controls technologies are reviewed to define approaches using active controls. A candidate control law for adaptive performance optimization is presented along with examples of algorithm operation.

A Rotatable Quality Control Phantom for Evaluating the Performance of Flat Panel Detectors in Imaging Moving Objects.

PubMed

Haga, Yoshihiro; Chida, Koichi; Inaba, Yohei; Kaga, Yuji; Meguro, Taiichiro; Zuguchi, Masayuki

2016-02-01

As the use of diagnostic X-ray equipment with flat panel detectors (FPDs) has increased, so has the importance of proper management of FPD systems. To ensure quality control (QC) of FPD system, an easy method for evaluating FPD imaging performance for both stationary and moving objects is required. Until now, simple rotatable QC phantoms have not been available for the easy evaluation of the performance (spatial resolution and dynamic range) of FPD in imaging moving objects. We developed a QC phantom for this purpose. It consists of three thicknesses of copper and a rotatable test pattern of piano wires of various diameters. Initial tests confirmed its stable performance. Our moving phantom is very useful for QC of FPD images of moving objects because it enables visual evaluation of image performance (spatial resolution and dynamic range) easily.

Mariner Mars 1971 attitude control subsystem flight performance

NASA Technical Reports Server (NTRS)

Schumacher, L.

1973-01-01

The flight performance of the Mariner 71 attitude control subsystem is discussed. Each phase of the mission is delineated and the attitude control subsystem is evaluated within the observed operational environment. Performance anomalies are introduced and discussed within the context of general performance. Problems such as the sun sensor interface incompatibility, gas valve leaks, and scan platform dynamic coupling effects are given analytical considerations.

Uniform peanut performance test 2017

USDA-ARS?s Scientific Manuscript database

The Uniform Peanut Performance Tests (UPPT) are designed to evaluate the commercial potential of advanced breeding peanut lines not formally released. The tests are performed in ten locations across the peanut production belt. In this study, 2 controls and 14 entries were evaluated at 8 locations....

Hand controllers for teleoperation. A state-of-the-art technology survey and evaluation

NASA Technical Reports Server (NTRS)

Brooks, T. L.; Bejczy, A. K.

1985-01-01

Hand controller technology for teleoperation is surveyed in three major catagories: (1) hand grip design, (2) control input devices, and (3) control strategies. In the first category, 14 hand grip designs are reviewed and evaluated in light of human factor considerations. In the second, 12 hand controller input devices are evaluated in terms of task performance, configuration and force feedback, controller/slave correspondence, operating volume, operator workload, human limitations, cross coupling, singularities, anthropomorphic characteristics, physical complexity, control/display interference, accuracy, technological base, cost, and reliability. In the third catagory, control strategies, commonly called control modes, are surveyed and evaluated. The report contains a bibliography with 189 select references on hand controller technology.

75 FR 34110 - Agency Information Collection Activities; Proposed Collection; Comment Request; Performance...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

...; Performance Evaluation Studies on Wastewater Laboratories (Renewal) AGENCY: Environmental Protection Agency... Evaluation Studies on Wastewater Laboratories (Renewal) ICR numbers: EPA ICR No. 0234.10, OMB Control No...

In-Flight Validation of a Pilot Rating Scale for Evaluating Failure Transients in Electronic Flight Control Systems

NASA Technical Reports Server (NTRS)

Kalinowski, Kevin F.; Tucker, George E.; Moralez, Ernesto, III

2006-01-01

Engineering development and qualification of a Research Flight Control System (RFCS) for the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A has motivated the development of a pilot rating scale for evaluating failure transients in fly-by-wire flight control systems. The RASCAL RFCS includes a highly-reliable, dual-channel Servo Control Unit (SCU) to command and monitor the performance of the fly-by-wire actuators and protect against the effects of erroneous commands from the flexible, but single-thread Flight Control Computer. During the design phase of the RFCS, two piloted simulations were conducted on the Ames Research Center Vertical Motion Simulator (VMS) to help define the required performance characteristics of the safety monitoring algorithms in the SCU. Simulated failures, including hard-over and slow-over commands, were injected into the command path, and the aircraft response and safety monitor performance were evaluated. A subjective Failure/Recovery Rating (F/RR) scale was developed as a means of quantifying the effects of the injected failures on the aircraft state and the degree of pilot effort required to safely recover the aircraft. A brief evaluation of the rating scale was also conducted on the Army/NASA CH-47B variable stability helicopter to confirm that the rating scale was likely to be equally applicable to in-flight evaluations. Following the initial research flight qualification of the RFCS in 2002, a flight test effort was begun to validate the performance of the safety monitors and to validate their design for the safe conduct of research flight testing. Simulated failures were injected into the SCU, and the F/RR scale was applied to assess the results. The results validate the performance of the monitors, and indicate that the Failure/Recovery Rating scale is a very useful tool for evaluating failure transients in fly-by-wire flight control systems.

76 FR 18615 - 30-Day Notice of Proposed Information Collection: Performance Measurement, Evaluation and Public...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-04

...: Performance Measurement, Evaluation and Public Diplomacy Program Surveys. OMB Control Number: 1405-0158. Type... and Cultural Affairs, Office of Policy and Evaluation, Evaluation Division (ECA/P/ V). Form Number: SV... State. [FR Doc. 2011-7931 Filed 4-1-11; 8:45 am] BILLING CODE 4710-05-P ...

Evaluation of EIT system performance.

PubMed

Yasin, Mamatjan; Böhm, Stephan; Gaggero, Pascal O; Adler, Andy

2011-07-01

An electrical impedance tomography (EIT) system images internal conductivity from surface electrical stimulation and measurement. Such systems necessarily comprise multiple design choices from cables and hardware design to calibration and image reconstruction. In order to compare EIT systems and study the consequences of changes in system performance, this paper describes a systematic approach to evaluate the performance of the EIT systems. The system to be tested is connected to a saline phantom in which calibrated contrasting test objects are systematically positioned using a position controller. A set of evaluation parameters are proposed which characterize (i) data and image noise, (ii) data accuracy, (iii) detectability of single contrasts and distinguishability of multiple contrasts, and (iv) accuracy of reconstructed image (amplitude, resolution, position and ringing). Using this approach, we evaluate three different EIT systems and illustrate the use of these tools to evaluate and compare performance. In order to facilitate the use of this approach, all details of the phantom, test objects and position controller design are made publicly available including the source code of the evaluation and reporting software.

Towards autonomous neuroprosthetic control using Hebbian reinforcement learning.

PubMed

Mahmoudi, Babak; Pohlmeyer, Eric A; Prins, Noeline W; Geng, Shijia; Sanchez, Justin C

2013-12-01

Our goal was to design an adaptive neuroprosthetic controller that could learn the mapping from neural states to prosthetic actions and automatically adjust adaptation using only a binary evaluative feedback as a measure of desirability/undesirability of performance. Hebbian reinforcement learning (HRL) in a connectionist network was used for the design of the adaptive controller. The method combines the efficiency of supervised learning with the generality of reinforcement learning. The convergence properties of this approach were studied using both closed-loop control simulations and open-loop simulations that used primate neural data from robot-assisted reaching tasks. The HRL controller was able to perform classification and regression tasks using its episodic and sequential learning modes, respectively. In our experiments, the HRL controller quickly achieved convergence to an effective control policy, followed by robust performance. The controller also automatically stopped adapting the parameters after converging to a satisfactory control policy. Additionally, when the input neural vector was reorganized, the controller resumed adaptation to maintain performance. By estimating an evaluative feedback directly from the user, the HRL control algorithm may provide an efficient method for autonomous adaptation of neuroprosthetic systems. This method may enable the user to teach the controller the desired behavior using only a simple feedback signal.

SIMS prototype system 1 test results: Engineering analysis

NASA Technical Reports Server (NTRS)

1978-01-01

The space and domestic water solar heating system designated SIMS Prototype Systems 1 was evaluated. The test system used 720 ft (gross) of Solar Energy Products Air Collectors, a Solar Control Corporation SAM 20 Air Handler with Model 75-175 control unit, a Jackson Solar Storage tank with Rho Sigma Mod 106 controller, and 20 tons of rack storage. The test data analysis performed evaluates the system performance and documents the suitability of SIMS Prototype System 1 hardware for field installation.

Evaluation of pavement marking performance.

DOT National Transportation Integrated Search

2008-06-01

The objective of the investigation was to evaluate the useful life of pavement markings. The Manual on Uniform Traffic Control Devices (MUTCD) provides general guidelines for the application and installation of pavement markings. However, performance...

A Perspective on Computational Human Performance Models as Design Tools

NASA Technical Reports Server (NTRS)

Jones, Patricia M.

2010-01-01

The design of interactive systems, including levels of automation, displays, and controls, is usually based on design guidelines and iterative empirical prototyping. A complementary approach is to use computational human performance models to evaluate designs. An integrated strategy of model-based and empirical test and evaluation activities is particularly attractive as a methodology for verification and validation of human-rated systems for commercial space. This talk will review several computational human performance modeling approaches and their applicability to design of display and control requirements.

The Effects of Performance Fatigability on Postural Control and Rehabilitation in the Older Patient

PubMed Central

Hassan, Mahdi; Bugnariu, Nicoleta

2016-01-01

Fatigue is common in older adults and has a significant effect on quality of life. Despite the high prevalence of fatigue in older individuals, several aspects are poorly understood. It is important to differentiate subjective fatigue complaints from fatigability of motor performance because the two are independent constructs with potentially distinct consequences on mobility. Performance fatigability is the magnitude of change in a performance criterion over a given time of task performance. Performance fatigability is a compulsory element of any strength training program, yet strength training is an important component of rehabilitation programs for older adults. The consequences of fatigability for older adults suggest that acute exercise of various types may result in acute impairments in postural control. The effects of performance fatigability on postural control in older adults are evaluated here to aid the rehabilitation clinician in making recommendations for evaluation of fall risks and exercise prescription. PMID:28154794

The Effects of Performance Fatigability on Postural Control and Rehabilitation in the Older Patient.

PubMed

Papa, Evan V; Hassan, Mahdi; Bugnariu, Nicoleta

2016-09-01

Fatigue is common in older adults and has a significant effect on quality of life. Despite the high prevalence of fatigue in older individuals, several aspects are poorly understood. It is important to differentiate subjective fatigue complaints from fatigability of motor performance because the two are independent constructs with potentially distinct consequences on mobility. Performance fatigability is the magnitude of change in a performance criterion over a given time of task performance. Performance fatigability is a compulsory element of any strength training program, yet strength training is an important component of rehabilitation programs for older adults. The consequences of fatigability for older adults suggest that acute exercise of various types may result in acute impairments in postural control. The effects of performance fatigability on postural control in older adults are evaluated here to aid the rehabilitation clinician in making recommendations for evaluation of fall risks and exercise prescription.

Modelling and temporal performances evaluation of networked control systems using (max, +) algebra

NASA Astrophysics Data System (ADS)

Ammour, R.; Amari, S.

2015-01-01

In this paper, we address the problem of temporal performances evaluation of producer/consumer networked control systems. The aim is to develop a formal method for evaluating the response time of this type of control systems. Our approach consists on modelling, using Petri nets classes, the behaviour of the whole architecture including the switches that support multicast communications used by this protocol. (max, +) algebra formalism is then exploited to obtain analytical formulas of the response time and the maximal and minimal bounds. The main novelty is that our approach takes into account all delays experienced at the different stages of networked automation systems. Finally, we show how to apply the obtained results through an example of networked control system.

Hand controller commonality evaluation process

NASA Technical Reports Server (NTRS)

Stuart, Mark A.; Bierschwale, John M.; Wilmington, Robert P.; Adam, Susan C.; Diaz, Manuel F.; Jensen, Dean G.

1990-01-01

A hand controller evaluation process has been developed to determine the appropriate hand controller configurations for supporting remotely controlled devices. These devices include remote manipulator systems (RMS), dexterous robots, and remotely-piloted free flyers. Standard interfaces were developed to evaluate six different hand controllers in three test facilities including dynamic computer simulations, kinematic computer simulations, and physical simulations. The hand controllers under consideration were six degree-of-freedom (DOF) position and rate minimaster and joystick controllers, and three-DOF rate controllers. Task performance data, subjective comments, and anthropometric data obtained during tests were used for controller configuration recommendations to the SSF Program.

The EyeHarp: A Gaze-Controlled Digital Musical Instrument

PubMed Central

Vamvakousis, Zacharias; Ramirez, Rafael

2016-01-01

We present and evaluate the EyeHarp, a new gaze-controlled Digital Musical Instrument, which aims to enable people with severe motor disabilities to learn, perform, and compose music using only their gaze as control mechanism. It consists of (1) a step-sequencer layer, which serves for constructing chords/arpeggios, and (2) a melody layer, for playing melodies and changing the chords/arpeggios. We have conducted a pilot evaluation of the EyeHarp involving 39 participants with no disabilities from both a performer and an audience perspective. In the first case, eight people with normal vision and no motor disability participated in a music-playing session in which both quantitative and qualitative data were collected. In the second case 31 people qualitatively evaluated the EyeHarp in a concert setting consisting of two parts: a solo performance part, and an ensemble (EyeHarp, two guitars, and flute) performance part. The obtained results indicate that, similarly to traditional music instruments, the proposed digital musical instrument has a steep learning curve, and allows to produce expressive performances both from the performer and audience perspective. PMID:27445885

Multicoordination Control Strategy Performance in Hybrid Power Systems

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

Pezzini, Paolo; Bryden, Kenneth M.; Tucker, David

This paper evaluates a state-space methodology of a multi-input multi-output (MIMO) control strategy using a 2 × 2 tightly coupled scenario applied to a physical gas turbine fuel cell hybrid power system. A centralized MIMO controller was preferred compared to a decentralized control approach because previous simulation studies showed that the coupling effect identified during the simultaneous control of the turbine speed and cathode airflow was better minimized. The MIMO controller was developed using a state-space dynamic model of the system that was derived using first-order transfer functions empirically obtained through experimental tests. The controller performance was evaluated in termsmore » of disturbance rejection through perturbations in the gas turbine operation, and setpoint tracking maneuver through turbine speed and cathode airflow steps. The experimental results illustrate that a multicoordination control strategy was able to mitigate the coupling of each actuator to each output during the simultaneous control of the system, and improved the overall system performance during transient conditions. On the other hand, the controller showed different performance during validation in simulation environment compared to validation in the physical facility, which will require a better dynamic modeling of the system for the implementation of future multivariable control strategies.« less

Multicoordination Control Strategy Performance in Hybrid Power Systems

DOE PAGES

Pezzini, Paolo; Bryden, Kenneth M.; Tucker, David

2018-04-11

This paper evaluates a state-space methodology of a multi-input multi-output (MIMO) control strategy using a 2 × 2 tightly coupled scenario applied to a physical gas turbine fuel cell hybrid power system. A centralized MIMO controller was preferred compared to a decentralized control approach because previous simulation studies showed that the coupling effect identified during the simultaneous control of the turbine speed and cathode airflow was better minimized. The MIMO controller was developed using a state-space dynamic model of the system that was derived using first-order transfer functions empirically obtained through experimental tests. The controller performance was evaluated in termsmore » of disturbance rejection through perturbations in the gas turbine operation, and setpoint tracking maneuver through turbine speed and cathode airflow steps. The experimental results illustrate that a multicoordination control strategy was able to mitigate the coupling of each actuator to each output during the simultaneous control of the system, and improved the overall system performance during transient conditions. On the other hand, the controller showed different performance during validation in simulation environment compared to validation in the physical facility, which will require a better dynamic modeling of the system for the implementation of future multivariable control strategies.« less

Image processing system performance prediction and product quality evaluation

NASA Technical Reports Server (NTRS)

Stein, E. K.; Hammill, H. B. (Principal Investigator)

1976-01-01

The author has identified the following significant results. A new technique for image processing system performance prediction and product quality evaluation was developed. It was entirely objective, quantitative, and general, and should prove useful in system design and quality control. The technique and its application to determination of quality control procedures for the Earth Resources Technology Satellite NASA Data Processing Facility are described.

34 CFR 361.82 - Evaluation standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... with disabilities under the VR program. (b) A DSU must achieve successful performance on both evaluation standards during each performance period. (c) The evaluation standards for the VR program are— (1... equal access to VR services. (Approved by the Office of Management and Budget under control number 1820...

34 CFR 361.82 - Evaluation standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... with disabilities under the VR program. (b) A DSU must achieve successful performance on both evaluation standards during each performance period. (c) The evaluation standards for the VR program are— (1... equal access to VR services. (Approved by the Office of Management and Budget under control number 1820...

34 CFR 361.82 - Evaluation standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... with disabilities under the VR program. (b) A DSU must achieve successful performance on both evaluation standards during each performance period. (c) The evaluation standards for the VR program are— (1... equal access to VR services. (Approved by the Office of Management and Budget under control number 1820...

34 CFR 361.82 - Evaluation standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

... with disabilities under the VR program. (b) A DSU must achieve successful performance on both evaluation standards during each performance period. (c) The evaluation standards for the VR program are— (1... equal access to VR services. (Approved by the Office of Management and Budget under control number 1820...

34 CFR 361.82 - Evaluation standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... with disabilities under the VR program. (b) A DSU must achieve successful performance on both evaluation standards during each performance period. (c) The evaluation standards for the VR program are— (1... equal access to VR services. (Approved by the Office of Management and Budget under control number 1820...

Kernel-based least squares policy iteration for reinforcement learning.

PubMed

Xu, Xin; Hu, Dewen; Lu, Xicheng

2007-07-01

In this paper, we present a kernel-based least squares policy iteration (KLSPI) algorithm for reinforcement learning (RL) in large or continuous state spaces, which can be used to realize adaptive feedback control of uncertain dynamic systems. By using KLSPI, near-optimal control policies can be obtained without much a priori knowledge on dynamic models of control plants. In KLSPI, Mercer kernels are used in the policy evaluation of a policy iteration process, where a new kernel-based least squares temporal-difference algorithm called KLSTD-Q is proposed for efficient policy evaluation. To keep the sparsity and improve the generalization ability of KLSTD-Q solutions, a kernel sparsification procedure based on approximate linear dependency (ALD) is performed. Compared to the previous works on approximate RL methods, KLSPI makes two progresses to eliminate the main difficulties of existing results. One is the better convergence and (near) optimality guarantee by using the KLSTD-Q algorithm for policy evaluation with high precision. The other is the automatic feature selection using the ALD-based kernel sparsification. Therefore, the KLSPI algorithm provides a general RL method with generalization performance and convergence guarantee for large-scale Markov decision problems (MDPs). Experimental results on a typical RL task for a stochastic chain problem demonstrate that KLSPI can consistently achieve better learning efficiency and policy quality than the previous least squares policy iteration (LSPI) algorithm. Furthermore, the KLSPI method was also evaluated on two nonlinear feedback control problems, including a ship heading control problem and the swing up control of a double-link underactuated pendulum called acrobot. Simulation results illustrate that the proposed method can optimize controller performance using little a priori information of uncertain dynamic systems. It is also demonstrated that KLSPI can be applied to online learning control by incorporating an initial controller to ensure online performance.

Piloted evaluation of an integrated propulsion and flight control simulator

NASA Technical Reports Server (NTRS)

Bright, Michelle M.; Simon, Donald L.

1992-01-01

A piloted evaluation of the integrated flight and propulsion control simulator for advanced integrated propulsion and airframe control design is described. The evaluation will cover control effector gains and deadbands, control effectiveness and control authority, and heads up display functionality. For this evaluation the flight simulator is configured for transition flight using an advanced Short Take-Off and Vertical Landing fighter aircraft model, a simplified high-bypass turbofan engine model, fighter cockpit displays, and pilot effectors. The piloted tasks used for rating displays and control effector gains are described. Pilot comments and simulation results confirm that the display symbology and control gains are very adequate for the transition flight task. Additionally, it is demonstrated that this small-scale, fixed base flight simulator facility can adequately perform a real time, piloted control evaluation.

Performance of Bipolar Disorder Patients in Attention Testing: Comparison with Normal Controls and Among Manic, Depressive, and Euthymic Phases.

PubMed

Camelo, Evelyn V M; Mograbi, Daniel; de Assis da Silva, Rafael; Bifano, Jaqueline; Wainstok, Mayra; Silveira, Luciana Angélica Silva; Netto, Tânia; Santana, Cristina M T; Cheniaux, Elie

2017-03-01

Several studies on cognition in bipolar disorder (BD) have been developed on the last decade. Neuropsychological evaluation of attention in BD patients is fundamental since alterations in attention affect other cognitive functions. Evaluate if performance of BD patients in attention tests varies according to each phase of the disease and verify if there are differences in attention when comparing BD patients with normal controls. The study included 101 BD patients, with ages between 18 and 65 years, being 52 euthymic, 22 manic and 27 depressive, besides 30 normal controls. All subjects were evaluated though Hamilton Depression Scale, Young Mania Rating Scale and Global Assessment of Functioning, bipolar version (CGI-BP). Attention was evaluated through a neuropsychological battery. Normal controls had a better performance in selective attention tests than BD patients. No differences were found among manic, depressive and euthymic phases. Attention is markedly impaired in BD. Nevertheless, the results of this study do not imply that the severity of the attention deficit in BD patients varies according to decease phase.

Continuous performance measurement in flight systems. [sequential control model

NASA Technical Reports Server (NTRS)

Connelly, E. M.; Sloan, N. A.; Zeskind, R. M.

1975-01-01

The desired response of many man machine control systems can be formulated as a solution to an optimal control synthesis problem where the cost index is given and the resulting optimal trajectories correspond to the desired trajectories of the man machine system. Optimal control synthesis provides the reference criteria and the significance of error information required for performance measurement. The synthesis procedure described provides a continuous performance measure (CPM) which is independent of the mechanism generating the control action. Therefore, the technique provides a meaningful method for online evaluation of man's control capability in terms of total man machine performance.

Design and numerical evaluation of full-authority flight control systems for conventional and thruster-augmented helicopters employed in NOE operations

NASA Technical Reports Server (NTRS)

Perri, Todd A.; Mckillip, R. M., Jr.; Curtiss, H. C., Jr.

1987-01-01

The development and methodology is presented for development of full-authority implicit model-following and explicit model-following optimal controllers for use on helicopters operating in the Nap-of-the Earth (NOE) environment. Pole placement, input-output frequency response, and step input response were used to evaluate handling qualities performance. The pilot was equipped with velocity-command inputs. A mathematical/computational trajectory optimization method was employed to evaluate the ability of each controller to fly NOE maneuvers. The method determines the optimal swashplate and thruster input histories from the helicopter's dynamics and the prescribed geometry and desired flying qualities of the maneuver. Three maneuvers were investigated for both the implicit and explicit controllers with and without auxiliary propulsion installed: pop-up/dash/descent, bob-up at 40 knots, and glideslope. The explicit controller proved to be superior to the implicit controller in performance and ease of design.

Screening studies of advanced control concepts for airbreathing engines

NASA Technical Reports Server (NTRS)

Ouzts, Peter J.; Lorenzo, Carl F.; Merrill, Walter C.

1993-01-01

The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Accordingly, the NASA Lewis Research Center has conducted screening studies of advanced control concepts for airbreathing engines to determine their potential impact on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed concepts was formulated by NASA and industry. These concepts were evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation, three target aircraft/engine combinations were considered: a military high performance fighter mission, a high speed civil transport mission, and a civil tiltrotor mission. Each of the advanced control concepts considered in the study were defined and described. The concept's potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts were also determined. Finally, the concepts were ranked with respect to the target aircraft/engine missions.

Evaluation of Application Accuracy and Performance of a Hydraulically Operated Variable-Rate Aerial Application System

USDA-ARS?s Scientific Manuscript database

An aerial variable-rate application system consisting of a DGPS-based guidance system, automatic flow controller, and hydraulically controlled pump/valve was evaluated for response time to rapidly changing flow requirements and accuracy of application. Spray deposition position error was evaluated ...

40 CFR 63.1426 - Process vent requirements for determining organic HAP concentration, control efficiency, and...

Code of Federal Regulations, 2013 CFR

2013-07-01

... performance test for those control techniques in accordance with paragraph (b)(6) of this section. The design..., immediately preceding the use of the control technique. A design evaluation shall also address other vent... paragraph (f)(1)(i) of this section, the design evaluation shall document the control efficiency and address...

Performance of Recycled Hot Mix Asphalt Mixtures

DOT National Transportation Integrated Search

1995-05-01

This research project was undertaken to evaluate the performance of recycled pavements in comparison to virgin (control) asphalt pavements. Five projects, each consisting of a recycled section and a control section, were subjected to detailed evaluat...

Control of large flexible space structures

NASA Technical Reports Server (NTRS)

Vandervelde, W. E.

1986-01-01

Progress in robust design of generalized parity relations, design of failure sensitive observers using the geometric system theory of Wonham, computational techniques for evaluation of the performance of control systems with fault tolerance and redundancy management features, and the design and evaluation od control systems for structures having nonlinear joints are described.

75 FR 63177 - Availability of FY 09 Grantee Performance Evaluation Reports for the Eight States of EPA Region 4...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-14

...-year evaluations of eight state air pollution control programs (Alabama Department of Environmental... Management, FL; Louisville Metro Air Pollution Control District, KY; Forsyth County Environmental Affairs... Regional Air Quality Agency, NC; Chattanooga-Hamilton County Air Pollution Control Bureau, TN; Memphis...

Experimental evaluation of model predictive control and inverse dynamics control for spacecraft proximity and docking maneuvers

NASA Astrophysics Data System (ADS)

Virgili-Llop, Josep; Zagaris, Costantinos; Park, Hyeongjun; Zappulla, Richard; Romano, Marcello

2018-03-01

An experimental campaign has been conducted to evaluate the performance of two different guidance and control algorithms on a multi-constrained docking maneuver. The evaluated algorithms are model predictive control (MPC) and inverse dynamics in the virtual domain (IDVD). A linear-quadratic approach with a quadratic programming solver is used for the MPC approach. A nonconvex optimization problem results from the IDVD approach, and a nonlinear programming solver is used. The docking scenario is constrained by the presence of a keep-out zone, an entry cone, and by the chaser's maximum actuation level. The performance metrics for the experiments and numerical simulations include the required control effort and time to dock. The experiments have been conducted in a ground-based air-bearing test bed, using spacecraft simulators that float over a granite table.

Air Traffic Control Experimentation and Evaluation with the NASA ATS-6 Satellite : Volume 6. Modem Evaluation Test

DOT National Transportation Integrated Search

1976-09-01

Results of performance evaluation of voice, digital data and ranging modems in the aeronautical satellite environment are given. Approximately 80 hours of modem performance data were acquired on board an FAA KC-135 jet aircraft operating over the Nor...

Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee.

PubMed

Hafner, Brian J; Willingham, Laura L; Buell, Noelle C; Allyn, Katheryn J; Smith, Douglas G

2007-02-01

To evaluate differences in function, performance, and preference between mechanical and microprocessor prosthetic knee control technologies. A-B-A-B reversal design. Home, community, and laboratory environments. Twenty-one unilateral, transfemoral amputees. Mechanical control prosthetic knee versus microprocessor control prosthetic knee (Otto Bock C-Leg). Stair rating, hill rating and time, obstacle course time, divided attention task accuracy and time, Amputee Mobility Predictor score, step activity, Prosthesis Evaluation Questionnaire score, Medical Outcomes Study 36-Item Short-Form Health Survey score, self-reported frequency of stumbles and falls, and self-reported concentration required for ambulation. Stair descent score, hill descent time, and hill sound-side step length showed significant (P<.01) improvement with the C-Leg. Users reported a significant (P<.05) decrease in frequency of stumbles and falls, frustration with falling, and difficulty in multitasking while using the microprocessor knee. Subject satisfaction with the C-Leg was significantly (P<.001) greater than the mechanical control prosthesis. The study population showed improved performance when negotiating stairs and hills, reduced frequency of stumbling and falling, and a preference for the microprocessor control C-Leg as compared with the mechanical control prosthetic knee.

Verification and Validation Methodology of Real-Time Adaptive Neural Networks for Aerospace Applications

NASA Technical Reports Server (NTRS)

Gupta, Pramod; Loparo, Kenneth; Mackall, Dale; Schumann, Johann; Soares, Fola

2004-01-01

Recent research has shown that adaptive neural based control systems are very effective in restoring stability and control of an aircraft in the presence of damage or failures. The application of an adaptive neural network with a flight critical control system requires a thorough and proven process to ensure safe and proper flight operation. Unique testing tools have been developed as part of a process to perform verification and validation (V&V) of real time adaptive neural networks used in recent adaptive flight control system, to evaluate the performance of the on line trained neural networks. The tools will help in certification from FAA and will help in the successful deployment of neural network based adaptive controllers in safety-critical applications. The process to perform verification and validation is evaluated against a typical neural adaptive controller and the results are discussed.

Cost effective prevention of reflective cracking of composite pavement.

DOT National Transportation Integrated Search

2011-09-01

Louisiana experimented with various techniques and treatments to control reflective cracking since the : 1970s. The objective of this study is to evaluate and compare different reflective cracking control : treatments by evaluating the performance, c...

Effects of spatially displaced feedback on remote manipulation tasks

NASA Technical Reports Server (NTRS)

Manahan, Meera K.; Stuart, Mark A.; Bierschwale, John M.; Hwang, Ellen Y.; Legendre, A. J.

1992-01-01

Several studies have been performed to determine the effects on computer and direct manipulation task performance when viewing conditions are spatially displaced. Whether results from these studies can be directly applied to remote manipulation tasks is quenstionable. The objective of this evaluation was to determine the effects of reversed, inverted, and inverted/reversed views on remote manipulation task performance using two 3-Degree of Freedom (DOF) hand controllers and a replica position hand controller. Results showed that trials using the inverted viewing condition showed the worst performance, followed by the inverted/reversed view and the reversed view when using the 2x3 DOF. However, these differences were not significant. The inverted and inverted/reversed viewing conditions were significantly worse than the normal and reversed viewing conditions when using the Kraft Replica. A second evaluation was conducted in which additional trials were performed with each viewing condition to determine the long term effects of spatially displaced views on task performance for the hand controllers. Results of the second evaluation indicated that there was more of a difference in performance between the perturbed viewing conditions and the normal viewing condition with the Kraft Replica than with the 2x3 DOF.

40 CFR Table 7 to Subpart Vvvv of... - Applicability and Timing of Notifications

Code of Federal Regulations, 2010 CFR

2010-07-01

... § 63.9(e). b. A notification of the date for the continuous monitoring system performance evaluation as... control device performance test and continuous monitoring system performance evaluation. ... Notifications 7 Table 7 to Subpart VVVV of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

Piloted evaluation of an integrated propulsion and flight control simulator

NASA Technical Reports Server (NTRS)

Bright, Michelle M.; Simon, Donald L.

1992-01-01

This paper describes a piloted evaluation of the integrated flight and propulsion control simulator at NASA Lewis Research Center. The purpose of this evaluation is to demonstrate the suitability and effectiveness of this fixed based simulator for advanced integrated propulsion and airframe control design. The evaluation will cover control effector gains and deadbands, control effectiveness and control authority, and heads up display functionality. For this evaluation the flight simulator is configured for transition flight using an advanced Short Take-Off and vertical Landing fighter aircraft model, a simplified high-bypass turbofan engine model, fighter cockpit, displays, and pilot effectors. The paper describes the piloted tasks used for rating displays and control effector gains. Pilot comments and simulation results confirm that the display symbology and control gains are very adequate for the transition flight task. Additionally, it is demonstrated that this small-scale, fixed base flight simulator facility can adequately perform a real time, piloted control evaluation.

40 CFR 63.5767 - What records must I keep?

Code of Federal Regulations, 2011 CFR

2011-07-01

... by an add-on control device (i.e., you are complying with organic HAP content limits, application...-average organic HAP content as determined in § 63.5749. (d) If your facility has an add-on control device... malfunction events; control device performance tests; and continuous monitoring system performance evaluations. ...

40 CFR 63.5767 - What records must I keep?

Code of Federal Regulations, 2010 CFR

2010-07-01

... by an add-on control device (i.e., you are complying with organic HAP content limits, application...-average organic HAP content as determined in § 63.5749. (d) If your facility has an add-on control device... malfunction events; control device performance tests; and continuous monitoring system performance evaluations. ...

Nursing students' self-evaluation using a video recording of foley catheterization: effects on students' competence, communication skills, and learning motivation.

PubMed

Yoo, Moon Sook; Yoo, Il Young; Lee, Hyejung

2010-07-01

An opportunity for a student to evaluate his or her own performance enhances self-awareness and promotes self-directed learning. Using three outcome measures of competency of procedure, communication skills, and learning motivation, the effects of self-evaluation using a video recording of the student's Foley catheterization was investigated in this study. The students in the experimental group (n = 20) evaluated their Foley catheterization performance by reviewing the video recordings of their own performance, whereas students in the control group (n = 20) received written evaluation guidelines only. The results showed that the students in the experimental group had better scores on competency (p < 0.001), communication skills (p < 0.001), and learning motivation (p = 0.018) than the control group at the post-test, which was conducted 8 weeks after the pretest. Self-awareness of one's own performance developed by reviewing a videotape appears to increase the competency of clinical skills in nursing students. Copyright 2010, SLACK Incorporated.

Life cycle cost assessment and performance evaluation of sediment control technologies.

DOT National Transportation Integrated Search

2015-10-01

This study was performed for the Georgia Department of Transportation (GDOT) : to better understand the environmental impacts associated with sediment control : technology currently employed on transportation projects. In this study, a review of : cu...

Effects of a Velocity-Vector Based Command Augmentation System and Synthetic Vision System Terrain Portrayal and Guidance Symbology Concepts on Single-Pilot Performance

NASA Technical Reports Server (NTRS)

Liu, Dahai; Goodrich, Kenneth H.; Peak, Bob

2010-01-01

This study investigated the effects of synthetic vision system (SVS) concepts and advanced flight controls on the performance of pilots flying a light, single-engine general aviation airplane. We evaluated the effects and interactions of two levels of terrain portrayal, guidance symbology, and flight control response type on pilot performance during the conduct of a relatively complex instrument approach procedure. The terrain and guidance presentations were evaluated as elements of an integrated primary flight display system. The approach procedure used in the study included a steeply descending, curved segment as might be encountered in emerging, required navigation performance (RNP) based procedures. Pilot performance measures consisted of flight technical performance, perceived workload, perceived situational awareness and subjective preference. The results revealed that an elevation based generic terrain portrayal significantly improved perceived situation awareness without adversely affecting flight technical performance or workload. Other factors (pilot instrument rating, control response type, and guidance symbology) were not found to significantly affect the performance measures.

A simulation evaluation of the engine monitoring and control system display

NASA Technical Reports Server (NTRS)

Abbott, Terence S.

1990-01-01

The Engine Monitoring and Control System (E-MACS) display is a new concept for an engine instrument display, the purpose of which is to provide an enhanced means for a pilot to control and monitor aircraft engine performance. It provides graphically-presented information about performance capabilities, current performance, and engine component or subsystem operational conditions relative to nominal conditions. The concept was evaluated by sixteen pilot-subjects against a traditional, state-of-the-art electronic engine display format. The results of this evaluation showed a substantial pilot preference for the E-MACS display relative to the traditional display. The results of the failure detection portion of the evaluation showed a 100 percent detection rate for the E-MACS display relative to a 57 percent rate for the traditional display. From these results, it is concluded that by providing this type of information in the cockpit, a reduction in pilot workload and an enhanced ability for detecting degraded or off-nominal conditions is probable, thus leading to an increase in operational safety.

Enhanced Attitude Control Experiment for SSTI Lewis Spacecraft

NASA Technical Reports Server (NTRS)

Maghami, Peoman G.

1997-01-01

The enhanced attitude control system experiment is a technology demonstration experiment on the NASA's small spacecraft technology initiative program's Lewis spacecraft to evaluate advanced attitude control strategies. The purpose of the enhanced attitude control system experiment is to evaluate the feasibility of designing and implementing robust multi-input/multi-output attitude control strategies for enhanced pointing performance of spacecraft to improve the quality of the measurements of the science instruments. Different control design strategies based on modern and robust control theories are being considered for the enhanced attitude control system experiment. This paper describes the experiment as well as the design and synthesis of a mixed H(sub 2)/H(sub infinity) controller for attitude control. The control synthesis uses a nonlinear programming technique to tune the controller parameters and impose robustness and performance constraints. Simulations are carried out to demonstrate the feasibility of the proposed attitude control design strategy. Introduction

Real-time closed-loop simulation and upset evaluation of control systems in harsh electromagnetic environments

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.

1989-01-01

Digital control systems for applications such as aircraft avionics and multibody systems must maintain adequate control integrity in adverse as well as nominal operating conditions. For example, control systems for advanced aircraft, and especially those with relaxed static stability, will be critical to flight and will, therefore, have very high reliability specifications which must be met regardless of operating conditions. In addition, multibody systems such as robotic manipulators performing critical functions must have control systems capable of robust performance in any operating environment in order to complete the assigned task reliably. Severe operating conditions for electronic control systems can result from electromagnetic disturbances caused by lightning, high energy radio frequency (HERF) transmitters, and nuclear electromagnetic pulses (NEMP). For this reason, techniques must be developed to evaluate the integrity of the control system in adverse operating environments. The most difficult and illusive perturbations to computer-based control systems that can be caused by an electromagnetic environment (EME) are functional error modes that involve no component damage. These error modes are collectively known as upset, can occur simultaneously in all of the channels of a redundant control system, and are software dependent. Upset studies performed to date have not addressed the assessment of fault tolerant systems and do not involve the evaluation of a control system operating in a closed-loop with the plant. A methodology for performing a real-time simulation of the closed-loop dynamics of a fault tolerant control system with a simulated plant operating in an electromagnetically harsh environment is presented. In particular, considerations for performing upset tests on the controller are discussed. Some of these considerations are the generation and coupling of analog signals representative of electromagnetic disturbances to a control system under test, analog data acquisition, and digital data acquisition from fault tolerant systems. In addition, a case study of an upset test methodology for a fault tolerant electromagnetic aircraft engine control system is presented.

Study on Performance of Integration Control by Man and Machine in Stage of Final Approaching for Spaceship Rendezvous and Docking

NASA Astrophysics Data System (ADS)

Zhou, Qianxiang; Liu, Zhongqi

With the development of manned space technology, space rendezvous and docking (RVD) technology will play a more and more important role. The astronauts’ participation in a final close period of man-machine combination control is an important way of RVD technology. Spacecraft RVD control involves control problem of a total of 12 degrees of freedom (location) and attitude which it relative to the inertial space the orbit. Therefore, in order to reduce the astronauts’ operation load and reduce the security requirements to the ground station and achieve an optimal performance of the whole man-machine system, it is need to study how to design the number of control parameters of astronaut or aircraft automatic control system. In this study, with the laboratory conditions on the ground, a method was put forward to develop an experimental system in which the performance evaluation of spaceship RVD integration control by man and machine could be completed. After the RVD precision requirements were determined, 26 male volunteers aged 20-40 took part in the performance evaluation experiments. The RVD integration control success rates and total thruster ignition time were chosen as evaluation indices. Results show that if less than three RVD parameters control tasks were finished by subject and the rest of parameters control task completed by automation, the RVD success rate would be larger than eighty-eight percent and the fuel consumption would be optimized. In addition, there were two subjects who finished the whole six RVD parameters control tasks by enough train. In conclusion, if the astronauts' role should be integrated into the RVD control, it was suitable for them to finish the heading, pitch and roll control in order to assure the man-machine system high performance. If astronauts were needed to finish all parameter control, two points should be taken into consideration, one was enough fuel and another was enough long operation time.

Internal Control, CPA Recognition and Performance Consequence: Evidence from Chinese Real Estate Enterprises

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Zhang, Lili; Geng, Yi

In recent years, internal control has caught more and more attention over the whole globe. However, whether internal control could improve business efficiency also lacks the empirical supports. Based on a sample size of 146 Chinese real estate enterprises, this study analyses the CPA’s recognition degree on firm’s implementing internal control, and its performance consequence. The evidence suggests that CPAs are able to give exact evaluation on firm’s internal control implement, and the higher the internal control implemented, the better performance the enterprise will have.

Predictive validity of driving-simulator assessments following traumatic brain injury: a preliminary study.

PubMed

Lew, Henry L; Poole, John H; Lee, Eun Ha; Jaffe, David L; Huang, Hsiu-Chen; Brodd, Edward

2005-03-01

To evaluate whether driving simulator and road test evaluations can predict long-term driving performance, we conducted a prospective study on 11 patients with moderate to severe traumatic brain injury. Sixteen healthy subjects were also tested to provide normative values on the simulator at baseline. At their initial evaluation (time-1), subjects' driving skills were measured during a 30-minute simulator trial using an automated 12-measure Simulator Performance Index (SPI), while a trained observer also rated their performance using a Driving Performance Inventory (DPI). In addition, patients were evaluated on the road by a certified driving evaluator. Ten months later (time-2), family members observed patients driving for at least 3 hours over 4 weeks and rated their driving performance using the DPI. At time-1, patients were significantly impaired on automated SPI measures of driving skill, including: speed and steering control, accidents, and vigilance to a divided-attention task. These simulator indices significantly predicted the following aspects of observed driving performance at time-2: handling of automobile controls, regulation of vehicle speed and direction, higher-order judgment and self-control, as well as a trend-level association with car accidents. Automated measures of simulator skill (SPI) were more sensitive and accurate than observational measures of simulator skill (DPI) in predicting actual driving performance. To our surprise, the road test results at time-1 showed no significant relation to driving performance at time-2. Simulator-based assessment of patients with brain injuries can provide ecologically valid measures that, in some cases, may be more sensitive than a traditional road test as predictors of long-term driving performance in the community.

Relationship of core self-evaluations traits--self-esteem, generalized self-efficacy, locus of control, and emotional stability--with job satisfaction and job performance: a meta-analysis.

PubMed

Judge, T A; Bono, J E

2001-02-01

This article presents meta-analytic results of the relationship of 4 traits--self-esteem, generalized self-efficacy, locus of control, and emotional stability (low neuroticism) with job satisfaction and job performance. With respect to job satisfaction, the estimated true score correlations were .26 for self-esteem, .45 for generalized self-efficacy, .32 for internal locus of control, and .24 for emotional stability. With respect to job performance, the correlations were .26 for self-esteem, .23 for generalized self-efficacy, .22 for internal locus of control, and .19 for emotional stability. In total, the results based on 274 correlations suggest that these traits are among the best dispositional predictors of job satisfaction and job performance. T. A. Judge, E. A. Locke. and C. C. Durham's (1997) theory of core self-evaluations is used as a framework for discussing similarities between the 4 traits and their relationships to satisfaction and performance.

Performance Evaluation of Engineered Structured Sorbents for Atmosphere Revitalization Systems On Board Crewed Space Vehicles and Habitats

NASA Technical Reports Server (NTRS)

Howard, David F.; Perry, Jay L.; Knox, James C.; Junaedi, Christian; Roychoudhury, Subir

2011-01-01

Engineered structured (ES) sorbents are being developed to meet the technical challenges of future crewed space exploration missions. ES sorbents offer the inherent performance and safety attributes of zeolite and other physical adsorbents but with greater structural integrity and process control to improve durability and efficiency over packed beds. ES sorbent techniques that are explored include thermally linked and pressure-swing adsorption beds for water-save dehumidification and sorbent-coated metal meshes for residual drying, trace contaminant control, and carbon dioxide control. Results from sub-scale performance evaluations of a thermally linked pressure-swing adsorbent bed and an integrated sub-scale ES sorbent system are discussed.

78 FR 68060 - Availability of FY 12 Grantee Performance Evaluation Reports for the Eight States of EPA Region 4...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-13

... County Air Pollution Control Bureau, TN; Shelby County Health Department, TN; Knox County Department of... evaluations of eight state air pollution control programs (Alabama Department of Environmental Management... Department, FL; Pinellas County Parks and Conservation Resources, FL; Louisville Metro Air Pollution Control...

Piloted Simulation Tests of Propulsion Control as Backup to Loss of Primary Flight Controls for a B747-400 Jet Transport

NASA Technical Reports Server (NTRS)

Bull, John; Mah, Robert; Hardy, Gordon; Sullivan, Barry; Jones, Jerry; Williams, Diane; Soukup, Paul; Winters, Jose

1997-01-01

Partial failures of aircraft primary flight control systems and structural damages to aircraft during flight have led to catastrophic accidents with subsequent loss of lives (e.g. DC-10, B-747, C-5, B-52, and others). Following the DC-10 accident at Sioux City, Iowa in 1989, the National Transportation Safety Board recommended 'Encourage research and development of backup flight control systems for newly certified wide-body airplanes that utilize an alternate source of motive power separate from that source used for the conventional control system.' This report describes the concept of a propulsion controlled aircraft (PCA), discusses pilot controls, displays, and procedures; and presents the results of a PCA piloted simulation test and evaluation of the B747-400 airplane conducted at NASA Ames Research Center in December, 1996. The purpose of the test was to develop and evaluate propulsion control throughout the full flight envelope of the B747-400 including worst case scenarios of engine failures and out of trim moments. Pilot ratings of PCA performance ranged from adequate to satisfactory. PCA performed well in unusual attitude recoveries at 35,000 ft altitude, performed well in fully coupled ILS approaches, performed well in single engine failures, and performed well at aft cg. PCA performance was primarily limited by out-of-trim moments.

A new robust adaptive controller for vibration control of active engine mount subjected to large uncertainties

NASA Astrophysics Data System (ADS)

Fakhari, Vahid; Choi, Seung-Bok; Cho, Chang-Hyun

2015-04-01

This work presents a new robust model reference adaptive control (MRAC) for vibration control caused from vehicle engine using an electromagnetic type of active engine mount. Vibration isolation performances of the active mount associated with the robust controller are evaluated in the presence of large uncertainties. As a first step, an active mount with linear solenoid actuator is prepared and its dynamic model is identified via experimental test. Subsequently, a new robust MRAC based on the gradient method with σ-modification is designed by selecting a proper reference model. In designing the robust adaptive control, structured (parametric) uncertainties in the stiffness of the passive part of the mount and in damping ratio of the active part of the mount are considered to investigate the robustness of the proposed controller. Experimental and simulation results are presented to evaluate performance focusing on the robustness behavior of the controller in the face of large uncertainties. The obtained results show that the proposed controller can sufficiently provide the robust vibration control performance even in the presence of large uncertainties showing an effective vibration isolation.

Evaluation of the intelligent cruise control system : volume 1 : study results

DOT National Transportation Integrated Search

1999-10-01

The Intelligent Cruise Control (ICC) system evaluation was based on an ICC Field Operational Test (FOT) performed in Michigan. The FOT involved 108 volunteers recruited to drive ten ICC-equipped Chrysler Concordes. Testing was initiated in July 1996 ...

Does evaluative pressure make you less or more distractible? Role of top-down attentional control over response selection.

PubMed

Normand, Alice; Bouquet, Cédric A; Croizet, Jean-Claude

2014-06-01

People's ability to resist cognitive distraction is crucial in many situations. The present research examines individuals' resistance to attentional distraction under conditions of evaluative pressure. In a series of 4 studies, participants had to complete various attentional tasks while believing their intelligence was or was not under the scrutiny of an experimenter. Using a spatial cuing paradigm, Studies 1 through 3 demonstrated that feeling evaluated led participants to implement stronger feature-based attentional control, which resulted in more (or less) distraction when irrelevant information matched (did not match) the searched-for target. Study 4 ruled out the possibility that the above effects were due to voluntary shifts of attention and demonstrated that the control settings implemented under evaluative pressure resulted in stronger goal-contingent response priming. Thus, the way individuals relate to the task-the performance context in which they are-induces strong attentional selection biases. Altogether, the present findings highlight an overlooked form of top-down modulation of attention based on performance self-relevance. Implications for both the current models of attentional control and the current hypotheses on the impact of evaluative pressure on cognition, as well as the consequences for more complex performances, are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Development of electrical feedback controlled heat pipes and the advanced thermal control flight experiment

NASA Technical Reports Server (NTRS)

Bienert, W. B.

1974-01-01

The development and characteristics of electrical feedback controlled heat pipes (FCHP) are discussed. An analytical model was produced to describe the performance of the FCHP under steady state and transient conditions. An advanced thermal control flight experiment was designed to demonstrate the performance of the thermal control component in a space environment. The thermal control equipment was evaluated on the ATS-F satellite to provide performance data for the components and to act as a thermal control system which can be used to provide temperature stability of spacecraft components in future applications.

An Adaptive Control Technology for Safety of a GTM-like Aircraft

NASA Technical Reports Server (NTRS)

Matsutani, Megumi; Crespo, Luis G.; Annaswamy, Anuradha; Jang, Jinho

2010-01-01

An adaptive control architecture for safe performance of a transport aircraft subject to various adverse conditions is proposed and verified in this report. This architecture combines a nominal controller based on a Linear Quadratic Regulator with integral action, and an adaptive controller that accommodates actuator saturation and bounded disturbances. The effectiveness of the baseline controller and its adaptive augmentation are evaluated using a stand-alone control veri fication methodology. Case studies that pair individual parameter uncertainties with critical flight maneuvers are studied. The resilience of the controllers is determined by evaluating the degradation in closed-loop performance resulting from increasingly larger deviations in the uncertain parameters from their nominal values. Symmetric and asymmetric actuator failures, flight upsets, and center of gravity displacements, are some of the uncertainties considered.

Experimental evaluation of the concept of supevisory manipulation

NASA Technical Reports Server (NTRS)

Brooks, T. L.; Sheridan, T. B.

1982-01-01

A computer-controlled teleoperator system which is based on task-referenced sensor-aided control has been developed to study supervisory manipulation. This system, called SUPERMAN, is capable of performing complicated tasks in real-time by utilizing the operator for high-level functions related to the unpredictable portions of a task, while the subordinate machine performs the more well-defined subtasks under human supervison. To determine whether supervisory control schemes such as these offer any advantage over manual control under real-time conditions, a number of experiments involving both simple and complicated tasks were performed. Six representative tasks were chosen for the study: (1) obtaining a tool from a rack, (2) returning the tool to the rack, (3) removing a nut, (4) placing samples in a storage bin, (5) opening and closing a valve, and (6) digging with a shovel. The experiments were performed under simulated conditions using four forms of manual control (i.e., switch rate, joystick rate, master-slave position control, and master-slave with force feedback), as well as supervisory control. Through these experiments the effectiveness and quality of control were evaluated on the basis of the time required to complete each portion of the task and the type and number of errors which occurred.

Application and Evaluation of Control Modes for Risk-Based Engine Performance Enhancements

NASA Technical Reports Server (NTRS)

Liu, Yuan; Litt, Jonathan S.; Sowers, T. Shane; Owen, A. Karl (Compiler); Guo, Ten-Huei

2014-01-01

The engine control system for civil transport aircraft imposes operational limits on the propulsion system to ensure compliance with safety standards. However, during certain emergency situations, aircraft survivability may benefit from engine performance beyond its normal limits despite the increased risk of failure. Accordingly, control modes were developed to improve the maximum thrust output and responsiveness of a generic high-bypass turbofan engine. The algorithms were designed such that the enhanced performance would always constitute an elevation in failure risk to a consistent predefined likelihood. This paper presents an application of these risk-based control modes to a combined engine/aircraft model. Through computer and piloted simulation tests, the aim is to present a notional implementation of these modes, evaluate their effects on a generic airframe, and demonstrate their usefulness during emergency flight situations. Results show that minimal control effort is required to compensate for the changes in flight dynamics due to control mode activation. The benefits gained from enhanced engine performance for various runway incursion scenarios are investigated. Finally, the control modes are shown to protect against potential instabilities during propulsion-only flight where all aircraft control surfaces are inoperable.

Application and Evaluation of Control Modes for Risk-Based Engine Performance Enhancements

NASA Technical Reports Server (NTRS)

Liu, Yuan; Litt, Jonathan S.; Sowers, T. Shane; Owen, A. Karl; Guo, Ten-Huei

2015-01-01

The engine control system for civil transport aircraft imposes operational limits on the propulsion system to ensure compliance with safety standards. However, during certain emergency situations, aircraft survivability may benefit from engine performance beyond its normal limits despite the increased risk of failure. Accordingly, control modes were developed to improve the maximum thrust output and responsiveness of a generic high-bypass turbofan engine. The algorithms were designed such that the enhanced performance would always constitute an elevation in failure risk to a consistent predefined likelihood. This paper presents an application of these risk-based control modes to a combined engine/aircraft model. Through computer and piloted simulation tests, the aim is to present a notional implementation of these modes, evaluate their effects on a generic airframe, and demonstrate their usefulness during emergency flight situations. Results show that minimal control effort is required to compensate for the changes in flight dynamics due to control mode activation. The benefits gained from enhanced engine performance for various runway incursion scenarios are investigated. Finally, the control modes are shown to protect against potential instabilities during propulsion-only flight where all aircraft control surfaces are inoperable.

Real-time simultaneous and proportional myoelectric control using intramuscular EMG

PubMed Central

Kuiken, Todd A; Hargrove, Levi J

2014-01-01

Objective Myoelectric prostheses use electromyographic (EMG) signals to control movement of prosthetic joints. Clinically available myoelectric control strategies do not allow simultaneous movement of multiple degrees of freedom (DOFs); however, the use of implantable devices that record intramuscular EMG signals could overcome this constraint. The objective of this study was to evaluate the real-time simultaneous control of three DOFs (wrist rotation, wrist flexion/extension, and hand open/close) using intramuscular EMG. Approach We evaluated task performance of five able-bodied subjects in a virtual environment using two control strategies with fine-wire EMG: (i) parallel dual-site differential control, which enabled simultaneous control of three DOFs and (ii) pattern recognition control, which required sequential control of DOFs. Main Results Over the course of the experiment, subjects using parallel dual-site control demonstrated increased use of simultaneous control and improved performance in a Fitts' Law test. By the end of the experiment, performance using parallel dual-site control was significantly better (up to a 25% increase in throughput) than when using sequential pattern recognition control for tasks requiring multiple DOFs. The learning trends with parallel dual-site control suggested that further improvements in performance metrics were possible. Subjects occasionally experienced difficulty in performing isolated single-DOF movements with parallel dual-site control but were able to accomplish related Fitts' Law tasks with high levels of path efficiency. Significance These results suggest that intramuscular EMG, used in a parallel dual-site configuration, can provide simultaneous control of a multi-DOF prosthetic wrist and hand and may outperform current methods that enforce sequential control. PMID:25394366

Real-time simultaneous and proportional myoelectric control using intramuscular EMG

NASA Astrophysics Data System (ADS)

Smith, Lauren H.; Kuiken, Todd A.; Hargrove, Levi J.

2014-12-01

Objective. Myoelectric prostheses use electromyographic (EMG) signals to control movement of prosthetic joints. Clinically available myoelectric control strategies do not allow simultaneous movement of multiple degrees of freedom (DOFs); however, the use of implantable devices that record intramuscular EMG signals could overcome this constraint. The objective of this study was to evaluate the real-time simultaneous control of three DOFs (wrist rotation, wrist flexion/extension, and hand open/close) using intramuscular EMG. Approach. We evaluated task performance of five able-bodied subjects in a virtual environment using two control strategies with fine-wire EMG: (i) parallel dual-site differential control, which enabled simultaneous control of three DOFs and (ii) pattern recognition control, which required sequential control of DOFs. Main results. Over the course of the experiment, subjects using parallel dual-site control demonstrated increased use of simultaneous control and improved performance in a Fitts’ Law test. By the end of the experiment, performance using parallel dual-site control was significantly better (up to a 25% increase in throughput) than when using sequential pattern recognition control for tasks requiring multiple DOFs. The learning trends with parallel dual-site control suggested that further improvements in performance metrics were possible. Subjects occasionally experienced difficulty in performing isolated single-DOF movements with parallel dual-site control but were able to accomplish related Fitts’ Law tasks with high levels of path efficiency. Significance. These results suggest that intramuscular EMG, used in a parallel dual-site configuration, can provide simultaneous control of a multi-DOF prosthetic wrist and hand and may outperform current methods that enforce sequential control.

Simulator evaluation of the effects of reduced spoiler and thrust authority on a decoupled longitudinal control system during landings in wind shear

NASA Technical Reports Server (NTRS)

Miller, G. K., Jr.

1981-01-01

The effect of reduced control authority, both in symmetric spoiler travel and thrust level, on the effectiveness of a decoupled longitudinal control system was examined during the approach and landing of the NASA terminal configured vehicle (TCV) aft flight deck simulator in the presence of wind shear. The evaluation was conducted in a fixed-base simulator that represented the TCV aft cockpit. There were no statistically significant effects of reduced spoiler and thrust authority on pilot performance during approach and landing. Increased wind severity degraded approach and landing performance by an amount that was often significant. However, every attempted landing was completed safely regardless of the wind severity. There were statistically significant differences in performance between subjects, but the differences were generally restricted to the control wheel and control-column activity during the approach.

Design and implementation of a controlled clinical trial to evaluate the effectiveness and efficiency of routine opt-out rapid human immunodeficiency virus screening in the emergency department.

PubMed

Haukoos, Jason S; Hopkins, Emily; Byyny, Richard L; Conroy, Amy A; Silverman, Morgan; Eisert, Sheri; Thrun, Mark; Wilson, Michael; Boyett, Brian; Heffelfinger, James D

2009-08-01

In 2006, the Centers for Disease Control and Prevention (CDC) released revised recommendations for performing human immunodeficiency virus (HIV) testing in health care settings, including implementing routine rapid HIV screening, the use of an integrated opt-out consent, and limited prevention counseling. Emergency departments (EDs) have been a primary focus of these efforts. These revised CDC recommendations were primarily based on feasibility studies and have not been evaluated through the application of rigorous research methods. This article describes the design and implementation of a large prospective controlled clinical trial to evaluate the CDC's recommendations in an ED setting. From April 15, 2007, through April 15, 2009, a prospective quasi-experimental equivalent time-samples clinical trial was performed to compare the clinical effectiveness and efficiency of routine (nontargeted) opt-out rapid HIV screening (intervention) to physician-directed diagnostic rapid HIV testing (control) in a high-volume urban ED. In addition, three nested observational studies were performed to evaluate the cost-effectiveness and patient and staff acceptance of the two rapid HIV testing methods. This article describes the rationale, methodologies, and study design features of this program evaluation clinical trial. It also provides details regarding the integration of the principal clinical trial and its nested observational studies. Such ED-based trials are rare, but serve to provide valid comparisons between testing approaches. Investigators should consider similar methodology when performing future ED-based health services research.

Evaluation of exercise capacity after severe stroke using robotics-assisted treadmill exercise: a proof-of-concept study.

PubMed

Stoller, O; de Bruin, E D; Schindelholz, M; Schuster, C; de Bie, R A; Hunt, K J

2013-01-01

Robotics-assisted treadmill exercise (RATE) with focus on motor recovery has become popular in early post-stroke rehabilitation but low endurance for exercise is highly prevalent in these individuals. This study aimed to develop an exercise testing method using robotics-assisted treadmill exercise to evaluate aerobic capacity after severe stroke. Constant load testing (CLT) based on body weight support (BWS) control, and incremental exercise testing (IET) based on guidance force (GF) control were implemented during RATE. Analyses focussed on step change, step response kinetics, and peak performance parameters of oxygen uptake. Three subjects with severe motor impairment 16-23 days post-stroke were included. CLT yielded reasonable step change values in oxygen uptake, whereas response kinetics of oxygen uptake showed low goodness of fit. Peak performance parameters were not obtained during IET. Exercise testing in post-stroke individuals with severe motor impairments using a BWS control strategy for CLT is deemed feasible and safe. Our approach yielded reasonable results regarding cardiovascular performance parameters. IET based on GF control does not provoke peak cardiovascular performance due to uncoordinated walking patterns. GF control needs further development to optimally demand active participation during RATE. The findings warrant further research regarding the evaluation of exercise capacity after severe stroke.

A control method for bilateral teleoperating systems

NASA Astrophysics Data System (ADS)

Strassberg, Yesayahu

1992-01-01

The thesis focuses on control of bilateral master-slave teleoperators. The bilateral control issue of teleoperators is studied and a new scheme that overcomes basic unsolved problems is proposed. A performance measure, based on the multiport modeling method, is introduced in order to evaluate and understand the limitations of earlier published bilateral control laws. Based on the study evaluating the different methods, the objective of the thesis is stated. The proposed control law is then introduced, its ideal performance is demonstrated, and conditions for stability and robustness are derived. It is shown that stability, desired performance, and robustness can be obtained under the assumption that the deviation of the model from the actual system satisfies certain norm inequalities and the measurement uncertainties are bounded. The proposed scheme is validated by numerical simulation. The simulated system is based on the configuration of the RAL (Robotics and Automation Laboratory) telerobot. From the simulation results it is shown that good tracking performance can be obtained. In order to verify the performance of the proposed scheme when applied to a real hardware system, an experimental setup of a three degree of freedom master-slave teleoperator (i.e. three degree of freedom master and three degree of freedom slave robot) was built. Three basic experiments were conducted to verify the performance of the proposed control scheme. The first experiment verified the master control law and its contribution to the robustness and performance of the entire system. The second experiment demonstrated the actual performance of the system while performing a free motion teleoperating task. From the experimental results, it is shown that the control law has good performance and is robust to uncertainties in the models of the master and slave.

Aircraft flight test trajectory control

NASA Technical Reports Server (NTRS)

Menon, P. K. A.; Walker, R. A.

1988-01-01

Two control law design techniques are compared and the performance of the resulting controllers evaluated. The design requirement is for a flight test trajectory controller (FTTC) capable of closed-loop, outer-loop control of an F-15 aircraft performing high-quality research flight test maneuvers. The maneuver modeling, linearization, and design methodologies utilized in this research, are detailed. The results of applying these FTTCs to a nonlinear F-15 simulation are presented.

Cochlear Implantation in Patients With Usher Syndrome Type IIa Increases Performance and Quality of Life.

PubMed

Hartel, Bas P; van Nierop, Josephine W I; Huinck, Wendy J; Rotteveel, Liselotte J C; Mylanus, Emmanuel A M; Snik, Ad F; Kunst, Henricus P M; Pennings, Ronald J E

2017-07-01

Usher syndrome type IIa (USH2a) is characterized by congenital moderate to severe hearing impairment and retinitis pigmentosa. Hearing rehabilitation starts in early childhood with the application of hearing aids. In some patients with USH2a, severe progression of hearing impairment leads to insufficient speech intelligibility with hearing aids and issues with adequate communication and safety. Cochlear implantation (CI) is the next step in rehabilitation of such patients. This study evaluates the performance and benefit of CI in patients with USH2a. Retrospective case-control study to evaluate the performance and benefit of CI in 16 postlingually deaf adults (eight patients with USH2a and eight matched controls). Performance and benefit were evaluated by a speech intelligibility test and three quality-of-life questionnaires. Patients with USH2a with a mean age of 59 years at implantation exhibited good performance after CI. The phoneme scores improved significantly from 41 to 87% in patients with USH2a (p = 0.02) and from 30 to 86% in the control group (p = 0.001). The results of the questionnaire survey demonstrated a clear benefit from CI. There were no differences in performance or benefit between patients with USH2a and control patients before and after CI. CI increases speech intelligibility and improves quality of life in patients with USH2a.

Effects of computing time delay on real-time control systems

NASA Technical Reports Server (NTRS)

Shin, Kang G.; Cui, Xianzhong

1988-01-01

The reliability of a real-time digital control system depends not only on the reliability of the hardware and software used, but also on the speed in executing control algorithms. The latter is due to the negative effects of computing time delay on control system performance. For a given sampling interval, the effects of computing time delay are classified into the delay problem and the loss problem. Analysis of these two problems is presented as a means of evaluating real-time control systems. As an example, both the self-tuning predicted (STP) control and Proportional-Integral-Derivative (PID) control are applied to the problem of tracking robot trajectories, and their respective effects of computing time delay on control performance are comparatively evaluated. For this example, the STP (PID) controller is shown to outperform the PID (STP) controller in coping with the delay (loss) problem.

Overcoming Bias: Cognitive Control Reduces Susceptibility to Framing Effects in Evaluating Musical Performance.

PubMed

Aydogan, Gökhan; Flaig, Nicole; Ravi, Srekar N; Large, Edward W; McClure, Samuel M; Margulis, Elizabeth Hellmuth

2018-04-18

Prior expectations can bias evaluative judgments of sensory information. We show that information about a performer's status can bias the evaluation of musical stimuli, reflected by differential activity of the ventromedial prefrontal cortex (vmPFC). Moreover, we demonstrate that decreased susceptibility to this confirmation bias is (a) accompanied by the recruitment of and (b) correlated with the white-matter structure of the executive control network, particularly related to the dorsolateral prefrontal cortex (dlPFC). By using long-duration musical stimuli, we were able to track the initial biasing, subsequent perception, and ultimate evaluation of the stimuli, examining the full evolution of these biases over time. Our findings confirm the persistence of confirmation bias effects even when ample opportunity exists to gather information about true stimulus quality, and underline the importance of executive control in reducing bias.

Development and Integration of Control System Models

NASA Technical Reports Server (NTRS)

Kim, Young K.

1998-01-01

The computer simulation tool, TREETOPS, has been upgraded and used at NASA/MSFC to model various complicated mechanical systems and to perform their dynamics and control analysis with pointing control systems. A TREETOPS model of Advanced X-ray Astrophysics Facility - Imaging (AXAF-1) dynamics and control system was developed to evaluate the AXAF-I pointing performance for Normal Pointing Mode. An optical model of Shooting Star Experiment (SSE) was also developed and its optical performance analysis was done using the MACOS software.

Inter-relationships between objective handwriting features and executive control among children with developmental dysgraphia.

PubMed

Rosenblum, Sara

2018-01-01

To describe handwriting and executive control features and their inter-relationships among children with developmental dysgraphia, in comparison to controls. Participants included 64 children, aged 10-12 years, 32 with dysgraphia based on the Handwriting Proficiency Screening Questionnaire (HPSQ) and 32 matched controls. Children copied a paragraph onto paper affixed to a digitizer that supplied handwriting process objective measures (Computerized Penmanship Evaluation Tool (ComPET). Their written product was evaluated by the Hebrew Handwriting Evaluation (HHE). Parents completed the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire about their child's executive control abilities. Significant group differences were found for handwriting performance measures (HHE and ComPET) and executive control domains (BRIEF). Based on one discriminate function, including handwriting performance and executive control measures, 98.4% of the participants were correctly classified into groups. Significant correlations were found in each group between working memory and legibility as well as for other executive domains and handwriting measures. Furthermore, twenty percent of the variability of the mean pressure applied towards the writing surface among children with was explained by their 'emotional control' (BRIEF). The results strongly suggest consideration of executive control domains to obtain better insight into handwriting impairment characteristics among children with dysgraphia to improve their identification, evaluation and the intervention process.

Inter-relationships between objective handwriting features and executive control among children with developmental dysgraphia

PubMed Central

2018-01-01

Objective To describe handwriting and executive control features and their inter-relationships among children with developmental dysgraphia, in comparison to controls. Method Participants included 64 children, aged 10–12 years, 32 with dysgraphia based on the Handwriting Proficiency Screening Questionnaire (HPSQ) and 32 matched controls. Children copied a paragraph onto paper affixed to a digitizer that supplied handwriting process objective measures (Computerized Penmanship Evaluation Tool (ComPET). Their written product was evaluated by the Hebrew Handwriting Evaluation (HHE). Parents completed the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire about their child's executive control abilities. Results Significant group differences were found for handwriting performance measures (HHE and ComPET) and executive control domains (BRIEF). Based on one discriminate function, including handwriting performance and executive control measures, 98.4% of the participants were correctly classified into groups. Significant correlations were found in each group between working memory and legibility as well as for other executive domains and handwriting measures. Furthermore, twenty percent of the variability of the mean pressure applied towards the writing surface among children with was explained by their 'emotional control' (BRIEF). Conclusion The results strongly suggest consideration of executive control domains to obtain better insight into handwriting impairment characteristics among children with dysgraphia to improve their identification, evaluation and the intervention process. PMID:29689111

Evaluation of active control technology for short haul aircraft. [cost effectiveness

NASA Technical Reports Server (NTRS)

Renshaw, J. H.; Bennett, J. A.; Harris, O. C.; Honrath, J. F.; Patterson, R. W.

1975-01-01

An evaluation of the economics of short-haul aircraft designed with active controls technology and low wing-loading to achieve short field performance with good ride quality is presented. Results indicate that for such a system incorporating gust load alleviation and augmented stability the direct operating cost is better than for aircraft without active controls.

Staff Reductions and Performance Evaluations: Teacher Views on the Roles of Administrators and Colleagues.

ERIC Educational Resources Information Center

Phelan, William T.

As part of an ongoing three-year investigation into the effects of declining enrollment and reduction in force (RIF) on teachers, this paper explores: (1) teacher acceptance of exclusive administrative control over performance evaluations, and (2) teacher preferences for colleague input into the evaluation process. A sample of 85 schools was drawn…

Closed-loop, pilot/vehicle analysis of the approach and landing task

NASA Technical Reports Server (NTRS)

Schmidt, D. K.; Anderson, M. R.

1985-01-01

Optimal-control-theoretic modeling and frequency-domain analysis is the methodology proposed to evaluate analytically the handling qualities of higher-order manually controlled dynamic systems. Fundamental to the methodology is evaluating the interplay between pilot workload and closed-loop pilot/vehicle performance and stability robustness. The model-based metric for pilot workload is the required pilot phase compensation. Pilot/vehicle performance and loop stability is then evaluated using frequency-domain techniques. When these techniques were applied to the flight-test data for thirty-two highly-augmented fighter configurations, strong correlation was obtained between the analytical and experimental results.

Efficient evaluation of wireless real-time control networks.

PubMed

Horvath, Peter; Yampolskiy, Mark; Koutsoukos, Xenofon

2015-02-11

In this paper, we present a system simulation framework for the design and performance evaluation of complex wireless cyber-physical systems. We describe the simulator architecture and the specific developments that are required to simulate cyber-physical systems relying on multi-channel, multihop mesh networks. We introduce realistic and efficient physical layer models and a system simulation methodology, which provides statistically significant performance evaluation results with low computational complexity. The capabilities of the proposed framework are illustrated in the example of WirelessHART, a centralized, real-time, multi-hop mesh network designed for industrial control and monitor applications.

Evaluation of Aeroservoelastic Effects on Flutter

NASA Technical Reports Server (NTRS)

Nagaraja, K. S.; Felt, Larry R.; Kraft, Raymond

1998-01-01

This report presents work performed by The Boeing Company to satisfy the deliverable "Evaluation of aeroservoelastic Effects on Symmetric Flutter" for Subtask 7 of Reference 1. The objective of this report is to incorporate the improved methods for studying the effects of a closed-loop control system on the aeroservoelastic behavior of the airplane planned under NASA HSR technical Integration Task 20 work. Also, a preliminary evaluation of the existing pitch control laws on symmetric flutter of the TCA configuration was addressed."The goal is to develop an improved modeling methodology and perform design studies that account for the aero-structures-systems interaction effects.

A program to evaluate a control system based on feedback of aerodynamic pressure differentials

NASA Technical Reports Server (NTRS)

Levy, D. W.; Finn, P.; Roskam, J.

1981-01-01

The use of aerodynamic pressure differentials to position a control surface is evaluated. The system is a differential pressure command loop, analogous to a position command loop, where the surface is commanded to move until a desired differential pressure across the surface is achieved. This type of control is more direct and accurate because it is the differential pressure which causes the control forces and moments. A frequency response test was performed in a low speed wind tunnel to measure the performance of the system. Both pressure and position feedback were tested. The pressure feedback performed as well as position feedback implying that the actuator, with a break frequency on the order of 10 Rad/sec, was the limiting component. Theoretical considerations indicate that aerodynamic lags will not appear below frequencies of 50 Rad/sec, or higher.

Evaluation of Variable Refrigerant Flow Systems Performance and the Enhanced Control Algorithm on Oak Ridge National Laboratory s Flexible Research Platform

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

Im, Piljae; Munk, Jeffrey D; Gehl, Anthony C

2015-06-01

A research project “Evaluation of Variable Refrigerant Flow (VRF) Systems Performance and the Enhanced Control Algorithm on Oak Ridge National Laboratory’s (ORNL’s) Flexible Research Platform” was performed to (1) install and validate the performance of Samsung VRF systems compared with the baseline rooftop unit (RTU) variable-air-volume (VAV) system and (2) evaluate the enhanced control algorithm for the VRF system on the two-story flexible research platform (FRP) in Oak Ridge, Tennessee. Based on the VRF system designed by Samsung and ORNL, the system was installed from February 18 through April 15, 2014. The final commissioning and system optimization were completed onmore » June 2, 2014, and the initial test for system operation was started the following day, June 3, 2014. In addition, the enhanced control algorithm was implemented and updated on June 18. After a series of additional commissioning actions, the energy performance data from the RTU and the VRF system were monitored from July 7, 2014, through February 28, 2015. Data monitoring and analysis were performed for the cooling season and heating season separately, and the calibrated simulation model was developed and used to estimate the energy performance of the RTU and VRF systems. This final report includes discussion of the design and installation of the VRF system, the data monitoring and analysis plan, the cooling season and heating season data analysis, and the building energy modeling study« less

The effects of arousal reappraisal on stress responses, performance and attention.

PubMed

Sammy, Nadine; Anstiss, Paul A; Moore, Lee J; Freeman, Paul; Wilson, Mark R; Vine, Samuel J

2017-11-01

This study examined the effects of arousal reappraisal on cardiovascular responses, demand and resource evaluations, self-confidence, performance and attention under pressurized conditions. A recent study by Moore et al. [2015. Reappraising threat: How to optimize performance under pressure. Journal of Sport and Exercise Psychology, 37(3), 339-343. doi: 10.1123/jsep.2014-0186 ] suggested that arousal reappraisal is beneficial to the promotion of challenge states and leads to improvements in single-trial performance. This study aimed to further the work of Moore and colleagues (2015) by examining the effects of arousal reappraisal on cardiovascular responses, demand and resource evaluations, self-confidence, performance and attention in a multi-trial pressurized performance situation. Participants were randomly assigned to either an arousal reappraisal intervention or control condition, and completed a pressurized dart throwing task. The intervention encouraged participants to view their physiological arousal as facilitative rather than debilitative to performance. Measures of cardiovascular reactivity, demand and resource evaluations, self-confidence, task performance and attention were recorded. The reappraisal group displayed more favorable cardiovascular reactivity and reported higher resource evaluations and higher self-confidence than the control group but no task performance or attention effects were detected. These findings demonstrate the strength of arousal reappraisal in promoting adaptive stress responses, perceptions of resources and self-confidence.

Performance Management as a Means of Teacher Evaluation: A South Australian Perspective

ERIC Educational Resources Information Center

Naidu, Sham

2011-01-01

The introduction of performance management in South Australian public schools raises a number of issues regarding the structure, purpose and control of the process itself and the consequences of teacher evaluation. Performance management has the potential to shape teaching and the culture of schools according to what it values and what it ignores.…

40 CFR Table 13 to Subpart Wwww of... - Applicability and Timing of Notifications

Code of Federal Regulations, 2010 CFR

2010-07-01

... performance evaluation as specified in § 63.9(g) The date of submission of notification of intent to conduct a... days after the completion of the add-on control device performance test and CMS performance evaluation. ... Notifications 13 Table 13 to Subpart WWWW of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

On-road Driving Performance of Patients with Bilateral Moderate and Advanced Glaucoma

PubMed Central

Bhorade, Anjali M.; Yom, Victoria H.; Barco, Peggy; Wilson, Bradley; Gordon, Mae; Carr, David

2017-01-01

Purpose To compare on-road driving performance of patients with moderate or advanced glaucoma to controls and evaluate factors associated with unsafe driving. Design Case-control pilot study. Methods A consecutive sample of 21 patients with bilateral moderate or advanced glaucoma from Washington University, St. Louis, MO and 38 community-dwelling controls were enrolled. Participants, ages 55–90 years, underwent a comprehensive clinical evaluation by a trained occupational therapist and an on-road driving evaluation by a masked driver rehabilitation specialist. Overall driving performance of pass vs. marginal/fail and number of wheel and/or brake interventions were recorded. Results Fifty-two percent of glaucoma participants scored a marginal/fail compared to 21% of controls (odds ratio [OR], 4.1; 95% CI, 1.30–13.14;p=.02). Glaucoma participants had a higher risk of wheel interventions than controls (OR, 4.67; 95% CI, 1.03–21.17;p=.046). There were no differences detected between glaucoma participants who scored a pass vs. marginal/fail for visual field mean deviation of the better (p=.62) or worse (p=.88) eye, binocular distance (p=.15) or near (p=.23) visual acuity, contrast sensitivity (p=.28) or glare (p=.88). However, glaucoma participants with a marginal/fail score performed worse on Trail Making Tests A (p=.03) and B (p=.05), right-sided Jamar grip strength (p=.02), Rapid Pace Walk (p=.03), Braking Response Time (p=.03), and identifying traffic signs (p=.05). Conclusions and Relevance Patients with bilateral moderate or advanced glaucoma are at risk for unsafe driving – particularly those with impairments on psychometric and mobility tests. A comprehensive clinical assessment and on-road driving evaluation is recommended to effectively evaluate driving safety of these patients. PMID:26949136

Man/terminal interaction evaluation of computer operating system command and control service concepts. [in Spacelab

NASA Technical Reports Server (NTRS)

Dodson, D. W.; Shields, N. L., Jr.

1978-01-01

The Experiment Computer Operating System (ECOS) of the Spacelab will allow the onboard Payload Specialist to command experiment devices and display information relative to the performance of experiments. Three candidate ECOS command and control service concepts were reviewed and laboratory data on operator performance was taken for each concept. The command and control service concepts evaluated included a dedicated operator's menu display from which all command inputs were issued, a dedicated command key concept with which command inputs could be issued from any display, and a multi-display concept in which command inputs were issued from several dedicated function displays. Advantages and disadvantages are discussed in terms of training, operational errors, task performance time, and subjective comments of system operators.

A Multiple Agent Model of Human Performance in Automated Air Traffic Control and Flight Management Operations

NASA Technical Reports Server (NTRS)

Corker, Kevin; Pisanich, Gregory; Condon, Gregory W. (Technical Monitor)

1995-01-01

A predictive model of human operator performance (flight crew and air traffic control (ATC)) has been developed and applied in order to evaluate the impact of automation developments in flight management and air traffic control. The model is used to predict the performance of a two person flight crew and the ATC operators generating and responding to clearances aided by the Center TRACON Automation System (CTAS). The purpose of the modeling is to support evaluation and design of automated aids for flight management and airspace management and to predict required changes in procedure both air and ground in response to advancing automation in both domains. Additional information is contained in the original extended abstract.

Study of Synthetic Vision Systems (SVS) and Velocity-vector Based Command Augmentation System (V-CAS) on Pilot Performance

NASA Technical Reports Server (NTRS)

Liu, Dahai; Goodrich, Ken; Peak, Bob

2006-01-01

This study investigated the effects of synthetic vision system (SVS) concepts and advanced flight controls on single pilot performance (SPP). Specifically, we evaluated the benefits and interactions of two levels of terrain portrayal, guidance symbology, and control-system response type on SPP in the context of lower-landing minima (LLM) approaches. Performance measures consisted of flight technical error (FTE) and pilot perceived workload. In this study, pilot rating, control type, and guidance symbology were not found to significantly affect FTE or workload. It is likely that transfer from prior experience, limited scope of the evaluation task, specific implementation limitations, and limited sample size were major factors in obtaining these results.

Benchmark simulation model no 2: general protocol and exploratory case studies.

PubMed

Jeppsson, U; Pons, M-N; Nopens, I; Alex, J; Copp, J B; Gernaey, K V; Rosen, C; Steyer, J-P; Vanrolleghem, P A

2007-01-01

Over a decade ago, the concept of objectively evaluating the performance of control strategies by simulating them using a standard model implementation was introduced for activated sludge wastewater treatment plants. The resulting Benchmark Simulation Model No 1 (BSM1) has been the basis for a significant new development that is reported on here: Rather than only evaluating control strategies at the level of the activated sludge unit (bioreactors and secondary clarifier) the new BSM2 now allows the evaluation of control strategies at the level of the whole plant, including primary clarifier and sludge treatment with anaerobic sludge digestion. In this contribution, the decisions that have been made over the past three years regarding the models used within the BSM2 are presented and argued, with particular emphasis on the ADM1 description of the digester, the interfaces between activated sludge and digester models, the included temperature dependencies and the reject water storage. BSM2-implementations are now available in a wide range of simulation platforms and a ring test has verified their proper implementation, consistent with the BSM2 definition. This guarantees that users can focus on the control strategy evaluation rather than on modelling issues. Finally, for illustration, twelve simple operational strategies have been implemented in BSM2 and their performance evaluated. Results show that it is an interesting control engineering challenge to further improve the performance of the BSM2 plant (which is the whole idea behind benchmarking) and that integrated control (i.e. acting at different places in the whole plant) is certainly worthwhile to achieve overall improvement.

Problems in air traffic management. I., Longitudinal prediction of effectiveness of air traffic controllers.

DOT National Transportation Integrated Search

1961-12-01

Current (1961) job performance evaluations and medical history data were obtained for 149 of 197 men trained in air traffic control work in 1956. Evaluations of psychological test and biographical data collected at the time they went through training...

ERTS-1 flight evaluation report, 23 April - 23 July 1973

NASA Technical Reports Server (NTRS)

1973-01-01

The flight performance of the ERTS-1 satellite is analyzed for orbits 3810 to 5100. Systems analyzed include: orbital parameters, power subsystem, attitude control, telemetry, orbit adjust, thermal control, and data collection. Documents and reports related to the evaluation are also included.

Distributed Evaluation Functions for Fault Tolerant Multi-Rover Systems

NASA Technical Reports Server (NTRS)

Agogino, Adrian; Turner, Kagan

2005-01-01

The ability to evolve fault tolerant control strategies for large collections of agents is critical to the successful application of evolutionary strategies to domains where failures are common. Furthermore, while evolutionary algorithms have been highly successful in discovering single-agent control strategies, extending such algorithms to multiagent domains has proven to be difficult. In this paper we present a method for shaping evaluation functions for agents that provide control strategies that both are tolerant to different types of failures and lead to coordinated behavior in a multi-agent setting. This method neither relies of a centralized strategy (susceptible to single point of failures) nor a distributed strategy where each agent uses a system wide evaluation function (severe credit assignment problem). In a multi-rover problem, we show that agents using our agent-specific evaluation perform up to 500% better than agents using the system evaluation. In addition we show that agents are still able to maintain a high level of performance when up to 60% of the agents fail due to actuator, communication or controller faults.

Flight-Test Validation and Flying Qualities Evaluation of a Rotorcraft UAV Flight Control System

NASA Technical Reports Server (NTRS)

Mettler, Bernard; Tuschler, Mark B.; Kanade, Takeo

2000-01-01

This paper presents a process of design and flight-test validation and flying qualities evaluation of a flight control system for a rotorcraft-based unmanned aerial vehicle (RUAV). The keystone of this process is an accurate flight-dynamic model of the aircraft, derived by using system identification modeling. The model captures the most relevant dynamic features of our unmanned rotorcraft, and explicitly accounts for the presence of a stabilizer bar. Using the identified model we were able to determine the performance margins of our original control system and identify limiting factors. The performance limitations were addressed and the attitude control system was 0ptimize.d for different three performance levels: slow, medium, fast. The optimized control laws will be implemented in our RUAV. We will first determine the validity of our control design approach by flight test validating our optimized controllers. Subsequently, we will fly a series of maneuvers with the three optimized controllers to determine the level of flying qualities that can be attained. The outcome enable us to draw important conclusions on the flying qualities requirements for small-scale RUAVs.

Evaluation of feedback interventions for improving the quality assurance of cancer screening in Japan: study design and report of the baseline survey.

PubMed

Machii, Ryoko; Saika, Kumiko; Higashi, Takahiro; Aoki, Ayako; Hamashima, Chisato; Saito, Hiroshi

2012-02-01

The importance of quality assurance in cancer screening has recently gained increasing attention in Japan. To evaluate and improve quality, checklists and process indicators have been developed. To explore effective methods of enhancing quality in cancer screening, we started a randomized control study of the methods of evaluation and feedback for cancer control from 2009 to 2014. We randomly assigned 1270 municipal governments, equivalent to 71% of all Japanese municipal governments that performed screening programs, into three groups. The high-intensity intervention groups (n = 425) were individually evaluated using both checklist performance and process indicator values, while the low-intensity intervention groups (n= 421) were individually evaluated on the basis of only checklist performance. The control group (n = 424) received only a basic report that included the national average of checklist performance scores. We repeated the survey for each municipality's quality assurance activity performance using checklists and process indicators. In this paper, we report our study design and the result of the baseline survey. The checklist adherence rates were especially low in the checklist elements related to invitation of individuals, detailed monitoring of process indicators such as cancer detection rates according to screening histories and appropriate selection of screening facilities. Screening rate and percentage of examinees who underwent detailed examination tended to be lower for large cities when compared with smaller cities for all cancer sites. The performance of the Japanese cancer screening program in 2009 was identified for the first time.

40 CFR 63.2354 - What performance tests, design evaluations, and performance evaluations must I conduct?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., appendix A, to determine compliance with the organic HAP or TOC emission limit, you may use EPA Method 18... formaldehyde control efficiency as a surrogate for total organic HAP or TOC efficiency, or at the outlet of a...

Design and experimental evaluation of robust controllers for a two-wheeled robot

NASA Astrophysics Data System (ADS)

Kralev, J.; Slavov, Ts.; Petkov, P.

2016-11-01

The paper presents the design and experimental evaluation of two alternative μ-controllers for robust vertical stabilisation of a two-wheeled self-balancing robot. The controllers design is based on models derived by identification from closed-loop experimental data. In the first design, a signal-based uncertainty representation obtained directly from the identification procedure is used, which leads to a controller of order 29. In the second design the signal uncertainty is approximated by an input multiplicative uncertainty, which leads to a controller of order 50, subsequently reduced to 30. The performance of the two μ-controllers is compared with the performance of a conventional linear quadratic controller with 17th-order Kalman filter. A proportional-integral controller of the rotational motion around the vertical axis is implemented as well. The control code is generated using Simulink® controller models and is embedded in a digital signal processor. Results from the simulation of the closed-loop system as well as experimental results obtained during the real-time implementation of the designed controllers are given. The theoretical investigation and experimental results confirm that the closed-loop system achieves robust performance in respect to the uncertainties related to the identified robot model.

The “Dry-Run” Analysis: A Method for Evaluating Risk Scores for Confounding Control

PubMed Central

Wyss, Richard; Hansen, Ben B.; Ellis, Alan R.; Gagne, Joshua J.; Desai, Rishi J.; Glynn, Robert J.; Stürmer, Til

2017-01-01

Abstract A propensity score (PS) model's ability to control confounding can be assessed by evaluating covariate balance across exposure groups after PS adjustment. The optimal strategy for evaluating a disease risk score (DRS) model's ability to control confounding is less clear. DRS models cannot be evaluated through balance checks within the full population, and they are usually assessed through prediction diagnostics and goodness-of-fit tests. A proposed alternative is the “dry-run” analysis, which divides the unexposed population into “pseudo-exposed” and “pseudo-unexposed” groups so that differences on observed covariates resemble differences between the actual exposed and unexposed populations. With no exposure effect separating the pseudo-exposed and pseudo-unexposed groups, a DRS model is evaluated by its ability to retrieve an unconfounded null estimate after adjustment in this pseudo-population. We used simulations and an empirical example to compare traditional DRS performance metrics with the dry-run validation. In simulations, the dry run often improved assessment of confounding control, compared with the C statistic and goodness-of-fit tests. In the empirical example, PS and DRS matching gave similar results and showed good performance in terms of covariate balance (PS matching) and controlling confounding in the dry-run analysis (DRS matching). The dry-run analysis may prove useful in evaluating confounding control through DRS models. PMID:28338910

A follow-up study of adolescent attempted suicide in Israel.

PubMed

Farbstein, Ilana; Dycian, Anat; Gothelf, Doron; King, Robert A; Cohen, Donald J; Kron, Shmuel; Apter, Alan

2002-11-01

(1) To compare the outcome of adolescent subjects who have made a suicide attempt with the outcome of matched controls, using their psychological and psychometric screening tests for military service at age 16.5 years. Their subsequent performance during military service between ages 18 and 21 was also evaluated. (2) To compare the prognosis of those attempters who received intensive psychiatric inpatient evaluation in a general hospital with the prognosis of those who received emergency room treatment only. The computerized military records of 216 adolescents, who had been treated between 1987 and 1988 for attempted suicide in a general hospital emergency room, prior to their induction into the army, were evaluated. They were rated on the following tests: cognitive/educational performance and psychosocial adaptation, psychiatric and psychological health diagnoses, and performance during their military service between 1989 and 1992. Although the female attempters had slightly more problems in the military than the controls, their overall prognosis was surprisingly good. The male suicide attempters did very poorly in their subsequent military service. There was no long-term advantage in having had a psychiatric evaluation performed in a hospital over a brief emergency room evaluation. Most differences between attempters and controls were in service performance, rather than in cognitive and psychometric tests. There may be marked differences between the sexes in the significance of attempted suicide and in the indications for intervention. The policy of mandatory general hospitalization for suicide attempters may need reevaluation.

Algorithms for detecting and predicting influenza outbreaks: metanarrative review of prospective evaluations

PubMed Central

Spreco, A; Timpka, T

2016-01-01

Objectives Reliable monitoring of influenza seasons and pandemic outbreaks is essential for response planning, but compilations of reports on detection and prediction algorithm performance in influenza control practice are largely missing. The aim of this study is to perform a metanarrative review of prospective evaluations of influenza outbreak detection and prediction algorithms restricted settings where authentic surveillance data have been used. Design The study was performed as a metanarrative review. An electronic literature search was performed, papers selected and qualitative and semiquantitative content analyses were conducted. For data extraction and interpretations, researcher triangulation was used for quality assurance. Results Eight prospective evaluations were found that used authentic surveillance data: three studies evaluating detection and five studies evaluating prediction. The methodological perspectives and experiences from the evaluations were found to have been reported in narrative formats representing biodefence informatics and health policy research, respectively. The biodefence informatics narrative having an emphasis on verification of technically and mathematically sound algorithms constituted a large part of the reporting. Four evaluations were reported as health policy research narratives, thus formulated in a manner that allows the results to qualify as policy evidence. Conclusions Awareness of the narrative format in which results are reported is essential when interpreting algorithm evaluations from an infectious disease control practice perspective. PMID:27154479

STS-43 Commander Blaha conducts DTO 1208 using laptop on OV-104's flight deck

NASA Image and Video Library

1991-08-11

STS043-03-009 (5 Aug 1991) ---- Astronaut John E. Blaha is pictured executing development test objective (DTO) 1208, Space Station Cursor Control Device Evaluation II and advanced applications. The purpose of the Cursor Control Device Experiment is to evaluate human performance under space flight conditions of cursor control devices which are similar to the devices under consideration for use onboard Space Station computers. Here, the mission commander uses a thumbball/handgrip control device. Each crewmember evaluated the different types of cursor control devices during the nine-day STS-43 mission. Other methods of cursor control evaluated were the built-in trackball, a side mounted trackball with restraints and an optical pad with mouse.

STS-43 MS Adamson conducts DTO 1208 using laptop on OV-104's flight deck

NASA Image and Video Library

1991-08-11

STS043-14-034 (2-11 Aug 1991) --- Astronaut James C. Adamson is pictured executing Development Test Objective (DTO) 1208, Space Station Cursor Control Device Evaluation II and Advanced Applications. The purpose of the Cursor Control Device Experiment is to evaluate human performance under space flight conditions of cursor control devices which are similar to the devices under consideration for use onboard space station computers. Here, the mission specialists uses a thumbball/handgrip control device. Each crewmember evaluated the different types of cursor control devices during the nine-day STS-43 mission. Other methods of cursor control evaluated were the built-in trackball, a side mounted trackball with restraints and an optical pad with mouse.

Reliability and performance evaluation of systems containing embedded rule-based expert systems

NASA Technical Reports Server (NTRS)

Beaton, Robert M.; Adams, Milton B.; Harrison, James V. A.

1989-01-01

A method for evaluating the reliability of real-time systems containing embedded rule-based expert systems is proposed and investigated. It is a three stage technique that addresses the impact of knowledge-base uncertainties on the performance of expert systems. In the first stage, a Markov reliability model of the system is developed which identifies the key performance parameters of the expert system. In the second stage, the evaluation method is used to determine the values of the expert system's key performance parameters. The performance parameters can be evaluated directly by using a probabilistic model of uncertainties in the knowledge-base or by using sensitivity analyses. In the third and final state, the performance parameters of the expert system are combined with performance parameters for other system components and subsystems to evaluate the reliability and performance of the complete system. The evaluation method is demonstrated in the context of a simple expert system used to supervise the performances of an FDI algorithm associated with an aircraft longitudinal flight-control system.

Animation-assisted CPRII program as a reminder tool in achieving effective one-person-CPR performance.

PubMed

Choa, Minhong; Cho, Junho; Choi, Young Hwan; Kim, Seungho; Sung, Ji Min; Chung, Hyun Soo

2009-06-01

The objective of this study is to compare the skill retention of two groups of lay persons, six months after their last CPR training. The intervention group was provided with animation-assisted CPRII (AA-CPRII) instruction on their cellular phones, and the control group had nothing but what they learned from their previous training. This study was a single blind randomized controlled trial. The participants' last CPR trainings were held at least six months ago. We revised our CPR animation for on-site CPR instruction content emphasizing importance of chest compression. Participants were randomized into two groups, the AA-CPRII group (n=42) and the control group (n=38). Both groups performed three cycles of CPR and their performances were video recorded. These video clips were assessed by three evaluators using a checklist. The psychomotor skills were evaluated using the ResusciAnne SkillReporter. Using the 30-point scoring checklist, the AA-CPRII group had a significantly better score compared to the control group (p<0.001). Psychomotor skills evaluated with the AA-CPRII group demonstrated better performance in hand positioning (p=0.025), compression depth (p=0.035) and compression rate (p<0.001) than the control group. The AA-CPRII group resulted in better checklist scores, including chest compression rate, depth and hand positioning. Animation-assisted CPR could be used as a reminder tool in achieving effective one-person-CPR performance. By installing the CPR instruction on cellular phones and having taught them CPR with it during the training enabled participants to perform better CPR.

Comparative cross-sectional study of masticatory performance and mastication predominance for patients with missing posterior teeth.

PubMed

Iwashita, Hayato; Tsukiyama, Yoshihiro; Kori, Hidehiro; Kuwatsuru, Rika; Yamasaki, Yo; Koyano, Kiyoshi

2014-10-01

Missing posterior teeth can decrease masticatory function and cause horizontal mastication deviation, i.e., mastication predominance. Mastication predominance may lead to abnormal tooth attrition and temporomandibular disorders. This study evaluated masticatory performance and mastication predominance in patients with missing posterior teeth to investigate effects of missing posterior teeth on masticatory performance and mastication predominance. Thirty volunteers with normal dentition (control group), 30 patients with unilateral missing posterior teeth (unilateral group), and 23 patients with bilateral missing posterior teeth (bilateral group) participated. Gummy jellies were used to evaluate participants' masticatory performance, and electromyography was used to assess the degree of mastication predominance. Chewing gums, gummy jellies, and peanuts were used as foods of various hardnesses for evaluating mastication predominance. Compared with the control group, masticatory performance did not differ in the unilateral group but was significantly decreased in the bilateral group. With chewing gum and gummy jellies, the degree of mastication predominance was significantly increased in both unilateral and bilateral groups than the control group. With peanuts, the degree of mastication predominance was significantly increased in the unilateral group than the control group. Although masticatory performance was not decreased in the unilateral group, the degree of mastication predominance was increased. Decreased masticatory performance was observed in the bilateral group, and for foods with normal hardness and soft foods, the degree of mastication predominance was increased. These results suggested that mastication predominance should be considered in the recovery of masticatory performance in patients with missing posterior teeth. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Evaluation of total energy-rate feedback for glidescope tracking in wind shear

NASA Technical Reports Server (NTRS)

Belcastro, C. M.; Ostroff, A. J.

1986-01-01

Low-altitude wind shear is recognized as an infrequent but significant hazard to all aircraft during take-off and landing. A total energy-rate sensor, which is potentially applicable to this problem, has been developed for measuring specific total energy-rate of an airplane with respect to the air mass. This paper presents control system designs, with and without energy-rate feedback, for the approach to landing of a transport airplane through severe wind shear and gusts to evaluate application of this sensor. A system model is developed which incorporates wind shear dynamics equations with the airplance equations of motion, thus allowing the control systems to be analyzed under various wind shears. The control systems are designed using optimal output feedback and are analyzed using frequency domain control theory techniques. Control system performance is evaluated using a complete nonlinear simulation of the airplane and a severe wind shear and gust data package. The analysis and simulation results indicate very similar stability and performance characteristics for the two designs. An implementation technique for distributing the velocity gains between airspeed and ground speed in the simulation is also presented, and this technique is shown to improve the performance characteristics of both designs.

High perfomance liquid chromatography fingerprint analysis for quality control of brotowali (Tinospora crispa)

NASA Astrophysics Data System (ADS)

Syarifah, V. B.; Rafi, M.; Wahyuni, W. T.

2017-05-01

Brotowali (Tinospora crispa) is widely used in Indonesia as ingredient of herbal medicine formulation. To ensure the quality, safety, and efficacy of herbal medicine products, its chemical constituents should be continuously evaluated. High performance liquid chromatography (HPLC) fingerprint is one of powerful technique for this quality control process. In this study, HPLC fingerprint analysis method was developed for quality control of brotowali. HPLC analysis was performed in C18 column and detection was performed using photodiode array detector. The optimum mobile phase for brotowali fingerprint was acetonitrile (ACN) and 0.1% formic acid in gradient elution mode at a flow rate of 1 mL/min. The number of peaks detected in HPLC fingerprint of brotowali was 32 peaks and 23 peaks for stems and leaves, respectively. Berberine as marker compound was detected at retention time of 20.525 minutes. Evaluation of analytical performance including precision, reproducibility, and stability prove that this HPLC fingerprint analysis was reliable and could be applied for quality control of brotowali.

Aquatic Plant Control Research Program: Literature Review of Economic Valuation of Aquatic Plant Control

DTIC Science & Technology

1991-02-01

200 words) Aquatic plant control is necessary to maintain the flow of benefits for which water resources projects are constructed and operated (e.g...but little work has been performed by the Corps to evaluate the economic benefits resulting from aquatic plant control programs. This report reviewed...the applicability of the project evaluation guidance, Principles and Guidelines (P&G), for the eval- uation of aquatic plant control benefits . It was

Evaluation of corrosion and corrosion control on interstate 89 bridge #30 and #31.

DOT National Transportation Integrated Search

2015-06-01

This report summarizes the evaluation of the performance of cathodic protection installed on I-89 bridges over : Gile Pond Road (NH Route 114) during a rehabilitation project in 1987. : Control bridges of I-89 over Hominy Pot Road, approximately 1.5 ...

Evaluation of functional color vision requirements and current color vision screening tests for air traffic control specialists.

DOT National Transportation Integrated Search

1990-08-01

An experiment was conducted to evaluate the relation of type and degree of color vision deficiency and aeromedical color vision screening test scores to performance of color-dependent tasks of Air Traffic Control Specialists. The subjects included 37...

Evaluation of innovative devices to control traffic entering from low-volume access points within a land closure.

DOT National Transportation Integrated Search

2014-04-01

This report describes the methodology and results of analyses performed to identify and evaluate : alternative methods to control traffic entering a lane closure on a two-lane, two-way road from low-volume : access points. Researchers documented the ...

Teachers' Perceptions of Administrative Autonomy-Supportive versus Controlling Behaviors: Factors That Influence Teacher Intrinsic Motivation and Relationships with Administrators

ERIC Educational Resources Information Center

Scudella, Christine M.

2015-01-01

Federal policy around supervision and evaluation has prompted state action to develop new evaluation systems to increase student achievement. Systems, such as the Framework for Educator Effectiveness implemented in Wisconsin, are tied to teacher performance as well as student achievement. This type of performance-based evaluation system relies on…

Flight evaluations of several hover control and display combinations for precise blind vertical landings

NASA Technical Reports Server (NTRS)

Schroeder, J. A.; Merrick, V. K.

1990-01-01

Several control and display concepts were evaluated on a variable-stability helicopter prior to future evaluations on a modified Harrier. The control and display concepts had been developed to enable precise hover maneuvers, station keeping, and vertical landings in simulated zero-visibility conditions and had been evaluated extensively in previous piloted simulations. Flight evaluations early in the program revealed several inadequacies in the display drive laws that were later corrected using an alternative design approach that integrated the control and display characteristics with the desired guidance law. While hooded, three pilots performed landing-pad captures followed by vertical landings with attitude-rate, attitude, and translation-velocity-command control systems. The latter control system incorporated a modified version of state-rate-feedback implicit-model following. Precise landing within 2 ft of the desired touchdown point were achieved.

NHTSA's heavy duty vehicle brake research program report number 11 : evaluation of stopping performance of trailer antilock brake systems

DOT National Transportation Integrated Search

1997-04-01

In order to better understand the functioning of antilock brake systems on pneumatically braked trailers, a series of tests were conducted to evaluate different ABS control strategies, performance variations among systems supplied by different manufa...

Synthetic Vision Systems in GA Cockpit-Evaluation of Basic Maneuvers Performed by Low Time GA Pilots During Transition from VMC to IMC

NASA Technical Reports Server (NTRS)

Takallu, M. A.; Wong, D. T.; Uenking, M. D.

2002-01-01

An experimental investigation was conducted to study the effectiveness of modern flight displays in general aviation cockpits for mitigating Low Visibility Loss of Control and the Controlled Flight Into Terrain accidents. A total of 18 General Aviation (GA) pilots with private pilot, single engine land rating, with no additional instrument training beyond private pilot license requirements, were recruited to evaluate three different display concepts in a fixed-based flight simulator at the NASA Langley Research Center's General Aviation Work Station. Evaluation pilots were asked to continue flight from Visual Meteorological Conditions (VMC) into Instrument Meteorological Conditions (IMC) while performing a series of 4 basic precision maneuvers. During the experiment, relevant pilot/vehicle performance variables, pilot control inputs and physiological data were recorded. Human factors questionnaires and interviews were administered after each scenario. Qualitative and quantitative data have been analyzed and the results are presented here. Pilot performance deviations from the established target values (errors) were computed and compared with the FAA Practical Test Standards. Results of the quantitative data indicate that evaluation pilots committed substantially fewer errors when using the Synthetic Vision Systems (SVS) displays than when they were using conventional instruments. Results of the qualitative data indicate that evaluation pilots perceived themselves to have a much higher level of situation awareness while using the SVS display concept.

U.S. Geological Survey Standard Reference Sample Project: Performance Evaluation of Analytical Laboratories

USGS Publications Warehouse

Long, H. Keith; Daddow, Richard L.; Farrar, Jerry W.

1998-01-01

Since 1962, the U.S. Geological Survey (USGS) has operated the Standard Reference Sample Project to evaluate the performance of USGS, cooperator, and contractor analytical laboratories that analyze chemical constituents of environmental samples. The laboratories are evaluated by using performance evaluation samples, called Standard Reference Samples (SRSs). SRSs are submitted to laboratories semi-annually for round-robin laboratory performance comparison purposes. Currently, approximately 100 laboratories are evaluated for their analytical performance on six SRSs for inorganic and nutrient constituents. As part of the SRS Project, a surplus of homogeneous, stable SRSs is maintained for purchase by USGS offices and participating laboratories for use in continuing quality-assurance and quality-control activities. Statistical evaluation of the laboratories results provides information to compare the analytical performance of the laboratories and to determine possible analytical deficiences and problems. SRS results also provide information on the bias and variability of different analytical methods used in the SRS analyses.

A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft equipped with wing spoilers

NASA Technical Reports Server (NTRS)

Brown, S. C.; Hardy, G. H.; Hindson, W. S.

1984-01-01

As part of a comprehensive flight-test investigation of short takeoff and landing (STOL) operating systems for the terminal systems for the terminal area, an automatic landing system has been developed and evaluated for a light wing-loading turboprop-powered aircraft. An advanced digital avionics system performed display, navigation, guidance, and control functions for the test aircraft. Control signals were generated in order to command powered actuators for all conventional controls and for a set of symmetrically driven wing spoilers. This report describes effects of the spoiler control on longitudinal autoland (automatic landing) performance. Flight-test results, with and without spoiler control, are presented and compared with available (basically, conventional takeoff and landing) performance criteria. These comparisons are augmented by results from a comprehensive simulation of the controlled aircraft that included representations of the microwave landing system navigation errors that were encountered in flight as well as expected variations in atmospheric turbulence and wind shear. Flight-test results show that the addition of spoiler control improves the touchdown performance of the automatic landing system. Spoilers improve longitudinal touchdown and landing pitch-attitude performance, particularly in tailwind conditions. Furthermore, simulation results indicate that performance would probably be satisfactory for a wider range of atmospheric disturbances than those encountered in flight. Flight results also indicate that the addition of spoiler control during the final approach does not result in any measurable change in glidepath track performance, and results in a very small deterioration in airspeed tracking. This difference contrasts with simulations results, which indicate some improvement in glidepath tracking and no appreciable change in airspeed tracking. The modeling problem in the simulation that contributed to this discrepancy with flight was not resolved.

Sediment and erosion control laboratory facility expansion.

DOT National Transportation Integrated Search

2016-08-01

The Sediment and Erosion Control Laboratory (SEC Lab), formerly the Hydraulics, Sedimentation, and : Erosion Control Laboratory, is operated by the Texas A&M Transportation Institutes Environment and : Planning Program. Performance evaluation prog...

Design of neural network model-based controller in a fed-batch microbial electrolysis cell reactor for bio-hydrogen gas production

NASA Astrophysics Data System (ADS)

Azwar; Hussain, M. A.; Abdul-Wahab, A. K.; Zanil, M. F.; Mukhlishien

2018-03-01

One of major challenge in bio-hydrogen production process by using MEC process is nonlinear and highly complex system. This is mainly due to the presence of microbial interactions and highly complex phenomena in the system. Its complexity makes MEC system difficult to operate and control under optimal conditions. Thus, precise control is required for the MEC reactor, so that the amount of current required to produce hydrogen gas can be controlled according to the composition of the substrate in the reactor. In this work, two schemes for controlling the current and voltage of MEC were evaluated. The controllers evaluated are PID and Inverse neural network (NN) controller. The comparative study has been carried out under optimal condition for the production of bio-hydrogen gas wherein the controller output is based on the correlation of optimal current and voltage to the MEC. Various simulation tests involving multiple set-point changes and disturbances rejection have been evaluated and the performances of both controllers are discussed. The neural network-based controller results in fast response time and less overshoots while the offset effects are minimal. In conclusion, the Inverse neural network (NN)-based controllers provide better control performance for the MEC system compared to the PID controller.

DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

PubMed

Ruano, M V; Ribes, J; Seco, A; Ferrer, J

2011-01-01

This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP.

Improving Primary Care Residents' Proficiency in the Diagnosis of Skin Cancer

PubMed Central

Gerbert, Barbara; Bronstone, Amy; Wolff, Mimi; Maurer, Toby; Berger, Timothy; Pantilat, Steven; McPhee, Stephen J

1998-01-01

OBJECTIVE To determine whether a brief, multicomponent intervention could improve the skin cancer diagnosis and evaluation planning performance of primary care residents to a level equivalent to that of dermatologists. PARTICIPANTS Fifty-two primary care residents (26 in the control group and 26 in the intervention group) and 13 dermatologists completed a pretest and posttest. DESIGN A randomized, controlled trial with pretest and posttest measurements of residents' ability to diagnose and make evaluation plans for lesions indicative of skin cancer. INTERVENTION The intervention included face-to-face feedback sessions focusing on residents' performance deficiencies; an interactive seminar including slide presentations, case examples, and live demonstrations; and the Melanoma Prevention Kit including a booklet, magnifying tool, measuring tool, and skin color guide. MEASUREMENTS AND MAIN RESULTS We compared the abilities of a control and an intervention group of primary care residents, and a group of dermatologists to diagnose and make evaluation plans for six categories of skin lesions including three types of skin cancer—malignant melanoma, squamous cell carcinoma, and basal cell carcinoma. At posttest, both the intervention and control group demonstrated improved performance, with the intervention group revealing significantly larger gains. The intervention group showed greater improvement than the control group across all six diagnostic categories (a gain of 13 percentage points vs 5, p < .05), and in evaluation planning for malignant melanoma (a gain of 46 percentage points vs 36, p < .05) and squamous cell carcinoma (a gain of 42 percentage points vs 21, p < .01). The intervention group performed as well as the dermatologists on five of the six skin cancer diagnosis and evaluation planning scores with the exception of the diagnosis of basal cell carcinoma. CONCLUSIONS Primary care residents can diagnose and make evaluation plans for cancerous skin lesions, including malignant melanoma, at a level equivalent to that of dermatologists if they receive relevant, targeted education. PMID:9502368

Designing and evaluating the effectiveness of a serious game for safe administration of blood transfusion: A randomized controlled trial.

PubMed

Tan, Apphia Jia Qi; Lee, Cindy Ching Siang; Lin, Patrick Yongxing; Cooper, Simon; Lau, Lydia Siew Tiang; Chua, Wei Ling; Liaw, Sok Ying

2017-08-01

Preparing nursing students for the knowledge and skills required for the administration and monitoring of blood components is crucial for entry into clinical practice. Serious games create opportunities to develop this competency, which can be used as a self-directed learning strategy to complement existing didactic learning and simulation-based strategies. To describe the development and evaluation of a serious game to improve nursing students' knowledge, confidence, and performance in blood transfusion. An experiential gaming model was applied to guide the design of the serious game environment. A clustered, randomized controlled trial was conducted with 103 second-year undergraduate nursing students who were randomized into control or experimental groups. After a baseline evaluation of the participants' knowledge and confidence on blood transfusion procedure, the experimental group undertook a blood transfusion serious game and completed a questionnaire to evaluate their learning experience. All participants' clinical performances were evaluated in a simulated environment. The post-test knowledge and confidence mean scores of the experimental group improved significantly (p<0.001) after the serious game intervention compared to pre-test mean scores and to post-test mean scores of the control group (p<0.001). However, no significance difference (p=0.11) was found between the experimental and control groups on the post-test performance mean scores. The participants evaluated the serious game positively. The study provided evidence on the effectiveness of a serious game in improving the knowledge and confidence of nursing students on blood transfusion practice. The features of this serious game could be further developed to incorporate additional scenarios with repetitive exercises and feedback to enhance the impact on clinical performance. Given the flexibility, practicality, and scalability of such a game, they can serve as a promising approach to optimize learning when blended with high-fidelity simulation. Copyright © 2017. Published by Elsevier Ltd.

Optimal Controller Design for the Microgravity Isolation Mount (MIM)

NASA Technical Reports Server (NTRS)

Hampton, R. David

1998-01-01

H2 controllers, when designed using an appropriate design model and carefully chosen frequency weightings, appear to provide robust performance and robust stability for Microgravity Isolation Mount (MIM). The STS-85 flight data will be used to evaluate the H2 controllers' performance on the actual hardware under working conditions. Next, full-order H-infinity controllers will be developed, as an intermediate step, in order to determine appropriate H-infinity performance weights for use in the mixed-norm design. Finally the basic procedure outlined above will be used to develop fixed-order mixed-norm controllers for MIM.

On the impact of `smart tyres' on existing ABS/EBD control systems

NASA Astrophysics Data System (ADS)

Cheli, Federico; Leo, Elisbetta; Melzi, Stefano; Sabbioni, Edoardo

2010-12-01

The paper focuses on the possibility of enhancing the performances of the ABS (Antilock Braking System)/EBD (electronic braking distribution) control system by using the additional information provided by 'smart tyres' (i.e. tyres with embedded sensors and digital-computing capability). In particular, on the basis of previous works [Braghin et al., Future car active controls through the measurement of contact forces and patch features, Veh. Syst. Dyn. 44 (2006), pp. 3-13], the authors assumed that these components should be able to provide estimates for the normal loads acting on the four wheels and for the tyre-road friction coefficient. The benefits produced by the introduction of these additional channels into the existing ABS/EBD control logic were evaluated through simulations carried out with a validated 14 degrees of freedom (dofs) vehicle + ABS/EBD control logic numerical model. The performance of the ABS control system was evaluated through a series of braking manoeuvres on straight track focusing the attention on μ -jump conditions, while the performance of the EBD control system was assessed by means of braking manoeuvres carried out considering several weight distributions.

Power-Aware Compiler Controllable Chip Multiprocessor

NASA Astrophysics Data System (ADS)

Shikano, Hiroaki; Shirako, Jun; Wada, Yasutaka; Kimura, Keiji; Kasahara, Hironori

A power-aware compiler controllable chip multiprocessor (CMP) is presented and its performance and power consumption are evaluated with the optimally scheduled advanced multiprocessor (OSCAR) parallelizing compiler. The CMP is equipped with power control registers that change clock frequency and power supply voltage to functional units including processor cores, memories, and an interconnection network. The OSCAR compiler carries out coarse-grain task parallelization of programs and reduces power consumption using architectural power control support and the compiler's power saving scheme. The performance evaluation shows that MPEG-2 encoding on the proposed CMP with four CPUs results in 82.6% power reduction in real-time execution mode with a deadline constraint on its sequential execution time. Furthermore, MP3 encoding on a heterogeneous CMP with four CPUs and four accelerators results in 53.9% power reduction at 21.1-fold speed-up in performance against its sequential execution in the fastest execution mode.

Test and evaluation of the HIDEC engine uptrim algorithm. [Highly Integrated Digital Electronic Control for aircraft

NASA Technical Reports Server (NTRS)

Ray, R. J.; Myers, L. P.

1986-01-01

The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrated engine-airframe control systems. Performance improvements will result from an adaptive engine stall margin mode, a highly integrated mode that uses the airplane flight conditions and the resulting inlet distortion to continuously compute engine stall margin. When there is excessive stall margin, the engine is uptrimmed for more thrust by increasing engine pressure ratio (EPR). The EPR uptrim logic has been evaluated and implemente into computer simulations. Thrust improvements over 10 percent are predicted for subsonic flight conditions. The EPR uptrim was successfully demonstrated during engine ground tests. Test results verify model predictions at the conditions tested.

The Use of Decentralized Control in the Design of a Large Segmented Space Reflector

NASA Technical Reports Server (NTRS)

Ryaciotaki-Boussalis, Helen; Mirmirani, Maj; Rad, Khosrow; Morales, Mauricio; Velazquez, Efrain; Chassiakos, Anastasios; Luzardo, Jose-Alberto

1997-01-01

The 3-dimensional model for a segmented reflector telescope is developed using finite element techniques. The structure is decomposed into six subsystems. System control design using neural networks is performed. Performance evaluation is demonstrated via simulation using PRO-MATLAB and SIMULINK.

Evaluating the impact of a pre-rotation workshop on student preparation for clinical advanced pharmacy practice experiences.

PubMed

Medina, Melissa S; Stark, Jennifer E; Vesta, Kimi S; Lockhart, Staci M

2008-10-01

This pilot study was designed to evaluate the impact of a pre-rotation workshop (PRW) on pharmacy students' clinical skills and preparation for clinical Advanced Pharmacy Practice Experiences (APPE) involving direct patient care. Randomized controlled trial of an educational intervention with Institutional Review Board approval. PRW activities designed to simulate rotation activities around five competencies, patient charts, medication histories, SOAP notes, patient presentations, and professionalism. Endpoints were evaluated using clinical rotation preceptors' evaluation of performance and students' performance on objective structured clinical exams (OSCE). Eight fourth-year students and eight GPA matched controls (20% of the total class) were selected to voluntarily participate. The PRW demonstrated a positive impact on students' clinical skills and preparation for rotations by improving OSCE performance. However, no significant differences were found between groups when comparing preceptor evaluations of skills on rotations. These results are limited by the small sample size, potential OSCE "test-wiseness" effects, lack of OSCE evaluator blinding to study groups, potential case specificity effects due to the limited number of cases used on the OSCE and possible lack of sensitivity of the rotation evaluation tool to capture true differences among the experimental and control group participants. The PRW was successful at advancing students' clinical skills and preparation for rotations and may be considered as a tool to help bridge didactic to clinical experiences in the Pharm.D. curriculum.

Teleoperator technology and system development, volume 1

NASA Technical Reports Server (NTRS)

1972-01-01

A two phase approach was undertaken to: (1) evaluate the performance of a general-purpose anthropomorphic manipulator with various controllers and display arrangements, (2) identify basic technical limitations of existing teleoperator designs, and associated controls and displays, and (3) identify, through experimentation, the effects that controls and displays have on the performance of an anthropomorphic manipulator. In Phase 1 the NASA-furnished manipulators, controls and displays were integrated with the remote maneuvering unit; in Phase 2 experiments were defined and performed to assess the utility of teleoperators for 6 typical space inspection, maintenance and repair tasks.

Smith predictor with sliding mode control for processes with large dead times

NASA Astrophysics Data System (ADS)

Mehta, Utkal; Kaya, İbrahim

2017-11-01

The paper discusses the Smith Predictor scheme with Sliding Mode Controller (SP-SMC) for processes with large dead times. This technique gives improved load-disturbance rejection with optimum input control signal variations. A power rate reaching law is incorporated in the sporadic part of sliding mode control such that the overall performance recovers meaningfully. The proposed scheme obtains parameter values by satisfying a new performance index which is based on biobjective constraint. In simulation study, the efficiency of the method is evaluated for robustness and transient performance over reported techniques.

MSFC Skylab attitude and pointing control system mission evaluation

NASA Technical Reports Server (NTRS)

Chubb, W. B.

1974-01-01

The results of detailed performance analyses of the attitude and pointing control system in-orbit hardware and software on Skylab are reported. Performance is compared with requirements, test results, and prelaunch predictions. A brief history of the altitude and pointing control system evolution leading to the launch configuration is presented. The report states that the attitude and pointing system satisfied all requirements.

Modeling and comparative study of linear and nonlinear controllers for rotary inverted pendulum

NASA Astrophysics Data System (ADS)

Lima, Byron; Cajo, Ricardo; Huilcapi, Víctor; Agila, Wilton

2017-01-01

The rotary inverted pendulum (RIP) is a problem difficult to control, several studies have been conducted where different control techniques have been applied. Literature reports that, although problem is nonlinear, classical PID controllers presents appropriate performances when applied to the system. In this paper, a comparative study of the performances of linear and nonlinear PID structures is carried out. The control algorithms are evaluated in the RIP system, using indices of performance and power consumption, which allow the categorization of control strategies according to their performance. This article also presents the modeling system, which has been estimated some of the parameters involved in the RIP system, using computer-aided design tools (CAD) and experimental methods or techniques proposed by several authors attended. The results indicate a better performance of the nonlinear controller with an increase in the robustness and faster response than the linear controller.

Improvement of the Performance of an Electrocoagulation Process System Using Fuzzy Control of pH.

PubMed

Demirci, Yavuz; Pekel, Lutfiye Canan; Altinten, Ayla; Alpbaz, Mustafa

2015-12-01

The removal efficiencies of electrocoagulation (EC) systems are highly dependent on the initial value of pH. If an EC system has an acidic influent, the pH of the effluent increases during the treatment process; conversely, if such a system has an alkaline influent, the pH of the effluent decreases during the treatment process. Thus, changes in the pH of the wastewater affect the efficiency of the EC process. In this study, we investigated the dynamic effects of pH. To evaluate approaches for preventing increases in the pH of the system, the MATLAB/Simulink program was used to develop and evaluate an on-line computer-based system for pH control. The aim of this work was to study Proportional-Integral-Derivative (PID) control and fuzzy control of the pH of a real textile wastewater purification process using EC. The performances and dynamic behaviors of these two control systems were evaluated based on determinations of COD, colour, and turbidity removal efficiencies.

Additional Development and Systems Analyses of Pneumatic Technology for High Speed Civil Transport Aircraft

NASA Technical Reports Server (NTRS)

Englar, Robert J.; Willie, F. Scott; Lee, Warren J.

1999-01-01

In the Task I portion of this NASA research grant, configuration development and experimental investigations have been conducted on a series of pneumatic high-lift and control surface devices applied to a generic High Speed Civil Transport (HSCT) model configuration to determine their potential for improved aerodynamic performance, plus stability and control of higher performance aircraft. These investigations were intended to optimize pneumatic lift and drag performance; provide adequate control and longitudinal stability; reduce separation flowfields at high angle of attack; increase takeoff/climbout lift-to-drag ratios; and reduce system complexity and weight. Experimental aerodynamic evaluations were performed on a semi-span HSCT generic model with improved fuselage fineness ratio and with interchangeable plain flaps, blown flaps, pneumatic Circulation Control Wing (CCW) high-lift configurations, plain and blown canards, a novel Circulation Control (CC) cylinder blown canard, and a clean cruise wing for reference. Conventional tail power was also investigated for longitudinal trim capability. Also evaluated was unsteady pulsed blowing of the wing high-lift system to determine if reduced pulsed mass flow rates and blowing requirements could be made to yield the same lift as that resulting from steady-state blowing. Depending on the pulsing frequency applied, reduced mass flow rates were indeed found able to provide lift augmentation at lesser blowing values than for the steady conditions. Significant improvements in the aerodynamic characteristics leading to improved performance and stability/control were identified, and the various components were compared to evaluate the pneumatic potential of each. Aerodynamic results were provided to the Georgia Tech Aerospace System Design Lab. to conduct the companion system analyses and feasibility study (Task 2) of theses concepts applied to an operational advanced HSCT aircraft. Results and conclusions from these experimental evaluations are presented herein, as are recommendations for further development and follow-on investigations. Also provided as an Appendix for reference are the basic results from the previous pneumatic HSCT investigations.

Glycemic penalty index for adequately assessing and comparing different blood glucose control algorithms

PubMed Central

Van Herpe, Tom; De Brabanter, Jos; Beullens, Martine; De Moor, Bart; Van den Berghe, Greet

2008-01-01

Introduction Blood glucose (BG) control performed by intensive care unit (ICU) nurses is becoming standard practice for critically ill patients. New (semi-automated) 'BG control' algorithms (or 'insulin titration' algorithms) are under development, but these require stringent validation before they can replace the currently used algorithms. Existing methods for objectively comparing different insulin titration algorithms show weaknesses. In the current study, a new approach for appropriately assessing the adequacy of different algorithms is proposed. Methods Two ICU patient populations (with different baseline characteristics) were studied, both treated with a similar 'nurse-driven' insulin titration algorithm targeting BG levels of 80 to 110 mg/dl. A new method for objectively evaluating BG deviations from normoglycemia was founded on a smooth penalty function. Next, the performance of this new evaluation tool was compared with the current standard assessment methods, on an individual as well as a population basis. Finally, the impact of four selected parameters (the average BG sampling frequency, the duration of algorithm application, the severity of disease, and the type of illness) on the performance of an insulin titration algorithm was determined by multiple regression analysis. Results The glycemic penalty index (GPI) was proposed as a tool for assessing the overall glycemic control behavior in ICU patients. The GPI of a patient is the average of all penalties that are individually assigned to each measured BG value based on the optimized smooth penalty function. The computation of this index returns a number between 0 (no penalty) and 100 (the highest penalty). For some patients, the assessment of the BG control behavior using the traditional standard evaluation methods was different from the evaluation with GPI. Two parameters were found to have a significant impact on GPI: the BG sampling frequency and the duration of algorithm application. A higher BG sampling frequency and a longer algorithm application duration resulted in an apparently better performance, as indicated by a lower GPI. Conclusion The GPI is an alternative method for evaluating the performance of BG control algorithms. The blood glucose sampling frequency and the duration of algorithm application should be similar when comparing algorithms. PMID:18302732

Quality Control and Nondestructive Evaluation Techniques for Composites. Part 1. Overview of Characterization Techniques for Composite Reliability

DTIC Science & Technology

1982-05-01

MONITORING AND MANAGEMENT , 34 7.0 NONDESTRUCTIVE EVALUATION ( NDE ) 37 8. 0 SURFACE NDE 44 9.0 PERFORMANCE AND PROOF TESTING 46 10.0 SUMMARY AND...Chemical Quality Assurance Testing 2. Processability Testing 3. Cure Monitoring and Management 4. Nondestructive Evaluation ( NDE ) 5. Performance and...the management concept for implementing the specific tests. Chemical analysis, nondestructive evaluation ( NDE ) and environmental fatigue testing of

Characteristics of on-road driving performance of persons with central vision loss who use bioptic telescopes.

PubMed

Wood, Joanne M; McGwin, Gerald; Elgin, Jennifer; Searcey, Karen; Owsley, Cynthia

2013-05-01

To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls. Participants included 23 persons (mean age = 33 ± 12 years) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a state bioptic driving program, and 23 visually normal age-matched controls (mean age = 33 ± 12 years). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection, and frequency of bioptic telescope use. Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls. Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation.

Reconfigurable Control Design for the Full X-33 Flight Envelope

NASA Technical Reports Server (NTRS)

Cotting, M. Christopher; Burken, John J.

2001-01-01

A reconfigurable control law for the full X-33 flight envelope has been designed to accommodate a failed control surface and redistribute the control effort among the remaining working surfaces to retain satisfactory stability and performance. An offline nonlinear constrained optimization approach has been used for the X-33 reconfigurable control design method. Using a nonlinear, six-degree-of-freedom simulation, three example failures are evaluated: ascent with a left body flap jammed at maximum deflection; entry with a right inboard elevon jammed at maximum deflection; and landing with a left rudder jammed at maximum deflection. Failure detection and identification are accomplished in the actuator controller. Failure response comparisons between the nominal control mixer and the reconfigurable control subsystem (mixer) show the benefits of reconfiguration. Single aerosurface jamming failures are considered. The cases evaluated are representative of the study conducted to prove the adequate and safe performance of the reconfigurable control mixer throughout the full flight envelope. The X-33 flight control system incorporates reconfigurable flight control in the existing baseline system.

Linear quadratic Gaussian and feedforward controllers for the DSS-13 antenna

NASA Technical Reports Server (NTRS)

Gawronski, W. K.; Racho, C. S.; Mellstrom, J. A.

1994-01-01

The controller development and the tracking performance evaluation for the DSS-13 antenna are presented. A trajectory preprocessor, linear quadratic Gaussian (LQG) controller, feedforward controller, and their combination were designed, built, analyzed, and tested. The antenna exhibits nonlinear behavior when the input to the antenna and/or the derivative of this input exceeds the imposed limits; for slewing and acquisition commands, these limits are typically violated. A trajectory preprocessor was designed to ensure that the antenna behaves linearly, just to prevent nonlinear limit cycling. The estimator model for the LQG controller was identified from the data obtained from the field test. Based on an LQG balanced representation, a reduced-order LQG controller was obtained. The feedforward controller and the combination of the LQG and feedforward controller were also investigated. The performance of the controllers was evaluated with the tracking errors (due to following a trajectory) and the disturbance errors (due to the disturbances acting on the antenna). The LQG controller has good disturbance rejection properties and satisfactory tracking errors. The feedforward controller has small tracking errors but poor disturbance rejection properties. The combined LQG and feedforward controller exhibits small tracking errors as well as good disturbance rejection properties. However, the cost for this performance is the complexity of the controller.

Pilot-in-the-Loop Evaluation of a Yaw Rate to Throttle Feedback Control with Enhanced Engine Response

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Guo, Ten-Huei; Sowers, T. Shane; Chicatelli, Amy K.; Fulton, Christopher E.; May, Ryan D.; Owen, A. Karl

2012-01-01

This paper describes the implementation and evaluation of a yaw rate to throttle feedback system designed to replace a damaged rudder. It can act as a Dutch roll damper and as a means to facilitate pilot input for crosswind landings. Enhanced propulsion control modes were implemented to increase responsiveness and thrust level of the engine, which impact flight dynamics and performance. Piloted evaluations were performed to determine the capability of the engines to substitute for the rudder function under emergency conditions. The results showed that this type of implementation is beneficial, but the engines' capability to replace the rudder is limited.

Evaluation of Performance and Perceptions of Electronic vs. Paper Multiple-Choice Exams

ERIC Educational Resources Information Center

Washburn, Shannon; Herman, James; Stewart, Randolph

2017-01-01

In the veterinary professional curriculum, methods of examination in many courses are transitioning from the traditional paper-based exams to electronic-based exams. Therefore, a controlled trial to evaluate the impact of testing methodology on examination performance in a veterinary physiology course was designed and implemented. Formalized…

Development of a Rubric for Collegiate Jazz Improvisation Performance Assessment

ERIC Educational Resources Information Center

Moore, Kendall Ryan

2016-01-01

The purpose of this study was to develop a jazz improvisation rubric for the evaluation of collegiate jazz improvisation. To create this measure, research objectives were devised to investigate the aurally-observed performer-controlled components of improvisation, which aurally-observed components should be evaluated in an improvisatory…

Use of Fiber Bragg Grating (FBG) sensors for performing automated bridge pier structural damage detection and scour monitoring.

DOT National Transportation Integrated Search

2012-04-01

The goal of this study was to evaluate the performance of Fiber Bragg Grating (FBG) sensors able to detect impacts with : different frequencies on a bridge pier. The FBG technology was evaluated under controlled conditions in a laboratory : flume set...

ENVIRONMENTAL RESEARCH BRIEF: LONG-TERM PERFORMANCE OF PERMEABLE REACTIVE BARRIERS USING ZERO-VALENT IRON: AN EVALUATION AT TWO SITES

EPA Science Inventory

Geochemical and microbiological factors that control long-term performance of subsurface permeable reactive barriers were evaluated at the Elizabeth City, NC and the Denver Federal Center, CO sites. These groundwater treatment systems use zero-valent iron filings to intercept an...

LANDSAT-1 and Landsat-2 flight evaluation report, 23 October 1976 to 23 January 1977

NASA Technical Reports Server (NTRS)

1977-01-01

Performance analyses for LANDSAT 1 and 2, launched respectively in 1972 and 1975, are reported. Operational controls are evaluated, as well as orbital parameters and various subsystems. Both satellites continue to perform their missions normally, in spite of past minor operational malfunctions.

Examining the relationships between span of control and manager job and unit performance outcomes.

PubMed

Wong, Carol A; Elliott-Miller, Pat; Laschinger, Heather; Cuddihy, Michael; Meyer, Raquel M; Keatings, Margaret; Burnett, Camille; Szudy, Natalie

2015-03-01

Our aim was to examine the combination of frontline manager (FLM) personal characteristics and span of control (SOC) on their job and unit performance outcomes. Healthcare downsizing and reform have contributed to larger spans for FLMs in Canadian hospitals and increased concerns about manager workload. Despite a heightened awareness of SOC issues among decision makers, there is limited empirical evidence related to the effects of SOC on outcomes. A non-experimental predictive survey design was used to examine FLM SOC in 14 Canadian academic hospitals. Managers (n = 121) completed an online survey of work characteristics and The Ottawa Hospital (TOH) SOC tool. Unit turnover data were collected from organisational databases. The combination of SOC and core self-evaluation significantly predicted role overload, work control and job satisfaction, but only SOC predicted unit adverse outcomes and neither significantly predicted unit turnover. The findings contribute to an understanding of connections between the combination of SOC and core self-evaluation and manager job and unit performance outcomes. Organisational strategies to create manageable FLM SOC are essential to ensure exemplary job and unit outcomes. Core self-evaluation is a personality characteristic that may enhance manager performance in the face of high spans of control. © 2013 John Wiley & Sons Ltd.

Performance Evaluation of Speech Recognition Systems as a Next-Generation Pilot-Vehicle Interface Technology

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Shelton, Kevin J.; Prinzel, Lawrence J., III; Bailey, Randall E.

2016-01-01

During the flight trials known as Gulfstream-V Synthetic Vision Systems Integrated Technology Evaluation (GV-SITE), a Speech Recognition System (SRS) was used by the evaluation pilots. The SRS system was intended to be an intuitive interface for display control (rather than knobs, buttons, etc.). This paper describes the performance of the current "state of the art" Speech Recognition System (SRS). The commercially available technology was evaluated as an application for possible inclusion in commercial aircraft flight decks as a crew-to-vehicle interface. Specifically, the technology is to be used as an interface from aircrew to the onboard displays, controls, and flight management tasks. A flight test of a SRS as well as a laboratory test was conducted.

Design of a video system providing optimal visual information for controlling payload and experiment operations with television

NASA Technical Reports Server (NTRS)

1975-01-01

A program was conducted which included the design of a set of simplified simulation tasks, design of apparatus and breadboard TV equipment for task performance, and the implementation of a number of simulation tests. Performance measurements were made under controlled conditions and the results analyzed to permit evaluation of the relative merits (effectivity) of various TV systems. Burden factors were subsequently generated for each TV system to permit tradeoff evaluation of system characteristics against performance. For the general remote operation mission, the 2-view system is recommended. This system is characterized and the corresponding equipment specifications were generated.

Influence of control parameters on the joint tracking performance of a coaxial weld vision system

NASA Technical Reports Server (NTRS)

Gangl, K. J.; Weeks, J. L.

1985-01-01

The first phase of a series of evaluations of a vision-based welding control sensor for the Space Shuttle Main Engine Robotic Welding System is described. The robotic welding system is presently under development at the Marshall Space Flight Center. This evaluation determines the standard control response parameters necessary for proper trajectory of the welding torch along the joint.

Environmental Control System Installer/Servicer (Residential Air Conditioning Mechanic). V-TECS Guide.

ERIC Educational Resources Information Center

Meyer, Calvin F.; Benson, Robert T.

This guide provides job relevant tasks, performance objectives, performance guides, resources, learning activitites, evaluation standards, and achievement testing in the occupation of environmental control system installer/servicer (residential air conditioning mechanic). It is designed to be used with any chosen teaching method. The course…

10 CFR 74.59 - Quality assurance and accounting requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... analyses and evaluations of the design, installation, preoperational tests, calibration, and operation of... performed at a pre-determined frequency, indicate a need for recalibration. Calibrations and tests must be... necessary for performance of the material control tests required by § 74.53(b). (e) Measurement control. The...

10 CFR 74.59 - Quality assurance and accounting requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... analyses and evaluations of the design, installation, preoperational tests, calibration, and operation of... performed at a pre-determined frequency, indicate a need for recalibration. Calibrations and tests must be... necessary for performance of the material control tests required by § 74.53(b). (e) Measurement control. The...

Development of an environmental chamber for evaluating the performance of low-cost air quality sensors under controlled conditions

NASA Astrophysics Data System (ADS)

Papapostolou, Vasileios; Zhang, Hang; Feenstra, Brandon J.; Polidori, Andrea

2017-12-01

A state-of-the-art integrated chamber system has been developed for evaluating the performance of low-cost air quality sensors. The system contains two professional grade chamber enclosures. A 1.3 m3 stainless-steel outer chamber and a 0.11 m3 Teflon-coated stainless-steel inner chamber are used to create controlled aerosol and gaseous atmospheres, respectively. Both chambers are temperature and relative humidity controlled with capability to generate a wide range of environmental conditions. The system is equipped with an integrated zero-air system, an ozone and two aerosol generation systems, a dynamic dilution calibrator, certified gas cylinders, an array of Federal Reference Method (FRM), Federal Equivalent Method (FEM), and Best Available Technology (BAT) reference instruments and an automated control and sequencing software. Our experiments have demonstrated that the chamber system is capable of generating stable and reproducible aerosol and gas concentrations at low, medium, and high levels. This paper discusses the development of the chamber system along with the methods used to quantitatively evaluate sensor performance. Considering that a significant number of academic and research institutions, government agencies, public and private institutions, and individuals are becoming interested in developing and using low-cost air quality sensors, it is important to standardize the procedures used to evaluate their performance. The information discussed herein provides a roadmap for entities who are interested in characterizing air quality sensors in a rigorous, systematic and reproducible manner.

Plan delivery quality assurance for CyberKnife: Statistical process control analysis of 350 film-based patient-specific QAs.

PubMed

Bellec, J; Delaby, N; Jouyaux, F; Perdrieux, M; Bouvier, J; Sorel, S; Henry, O; Lafond, C

2017-07-01

Robotic radiosurgery requires plan delivery quality assurance (DQA) but there has never been a published comprehensive analysis of a patient-specific DQA process in a clinic. We proposed to evaluate 350 consecutive film-based patient-specific DQAs using statistical process control. We evaluated the performance of the process to propose achievable tolerance criteria for DQA validation and we sought to identify suboptimal DQA using control charts. DQAs were performed on a CyberKnife-M6 using Gafchromic-EBT3 films. The signal-to-dose conversion was performed using a multichannel-correction and a scanning protocol that combined measurement and calibration in a single scan. The DQA analysis comprised a gamma-index analysis at 3%/1.5mm and a separate evaluation of spatial and dosimetric accuracy of the plan delivery. Each parameter was plotted on a control chart and control limits were calculated. A capability index (Cpm) was calculated to evaluate the ability of the process to produce results within specifications. The analysis of capability showed that a gamma pass rate of 85% at 3%/1.5mm was highly achievable as acceptance criteria for DQA validation using a film-based protocol (Cpm>1.33). 3.4% of DQA were outside a control limit of 88% for gamma pass-rate. The analysis of the out-of-control DQA helped identify a dosimetric error in our institute for a specific treatment type. We have defined initial tolerance criteria for DQA validations. We have shown that the implementation of a film-based patient-specific DQA protocol with the use of control charts is an effective method to improve patient treatment safety on CyberKnife. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

An Overview of Controls and Flying Qualities Technology on the F/A-18 High Alpha Research Vehicle

NASA Technical Reports Server (NTRS)

Pahle, Joseph W.; Wichman, Keith D.; Foster, John V.; Bundick, W. Thomas

1996-01-01

The NASA F/A-18 High Alpha Research Vehicle (HARV) has been the flight test bed of a focused technology effort to significantly increase maneuvering capability at high angles of attack. Development and flight test of control law design methodologies, handling qualities metrics, performance guidelines, and flight evaluation maneuvers are described. The HARV has been modified to include two research control effectors, thrust vectoring, and actuated forebody strakes in order to provide increased control power at high angles of attack. A research flight control system has been used to provide a flexible, easily modified capability for high-angle-of-attack research controls. Different control law design techniques have been implemented and flight-tested, including eigenstructure assignment, variable gain output feedback, pseudo controls, and model-following. Extensive piloted simulation has been used to develop nonlinear performance guide-lines and handling qualities criteria for high angles of attack. This paper reviews the development and evaluation of technologies useful for high-angle-of-attack control. Design, development, and flight test of the research flight control system, control laws, flying qualities specifications, and flight test maneuvers are described. Flight test results are used to illustrate some of the lessons learned during flight test and handling qualities evaluations.

Evaluation of New Jersey Route 18 OPAC/MIST traffic-control system

DOT National Transportation Integrated Search

1997-01-01

Conventional traffic-control strategies have limitations in handling unanticipated traffic demands. An adaptive traffic-signal control is expected to mitigate this problem and improve overall system performance. Furthermore, with the increasing needs...

Field Evaluation of Fracture Control in Tunnel Blasting

DOT National Transportation Integrated Search

1979-12-01

The objective of this research was to implement fracture control procedures in a tunnel project and to assess the practicality, advantages, disadvantages, performance and cost effectiveness of fracture control methods against smooth blasting procedur...

Evaluation of high-voltage, high-power, solid-state remote power controllers for amps

NASA Technical Reports Server (NTRS)

Callis, Charles P.

1987-01-01

The Electrical Power Branch at Marshall Space Flight Center has a Power System Development Facility where various power circuit breadboards are tested and evaluated. This project relates to the evaluation of a particular remote power controller (RPC) energizing high power loads. The Facility equipment permits the thorough testing and evaluation of high-voltage, high-power solid-state remote power controllers. The purpose is to evaluate a Type E, 30 Ampere, 200 V dc remote power controller. Three phases of the RPC evaluation are presented. The RPC is evaluated within a low-voltage, low-power circuit to check its operational capability. The RPC is then evaluated while performing switch/circuit breaker functions within a 200 V dc, 30 Ampere power circuit. The final effort of the project relates to the recommended procedures for installing these RPC's into the existing Autonomously Managed Power System (AMPS) breadboard/test facility at MSFC.

Preliminary supersonic flight test evaluation of performance seeking control

NASA Technical Reports Server (NTRS)

Orme, John S.; Gilyard, Glenn B.

1993-01-01

Digital flight and engine control, powerful onboard computers, and sophisticated controls techniques may improve aircraft performance by maximizing fuel efficiency, maximizing thrust, and extending engine life. An adaptive performance seeking control system for optimizing the quasi-steady state performance of an F-15 aircraft was developed and flight tested. This system has three optimization modes: minimum fuel, maximum thrust, and minimum fan turbine inlet temperature. Tests of the minimum fuel and fan turbine inlet temperature modes were performed at a constant thrust. Supersonic single-engine flight tests of the three modes were conducted using varied after burning power settings. At supersonic conditions, the performance seeking control law optimizes the integrated airframe, inlet, and engine. At subsonic conditions, only the engine is optimized. Supersonic flight tests showed improvements in thrust of 9 percent, increases in fuel savings of 8 percent, and reductions of up to 85 deg R in turbine temperatures for all three modes. The supersonic performance seeking control structure is described and preliminary results of supersonic performance seeking control tests are given. These findings have implications for improving performance of civilian and military aircraft.

Current Performance Characteristics of NASA Langley Research Center's Cockpit Motion Base and Standardized Test Procedure for Future Performance Characterization

NASA Technical Reports Server (NTRS)

Cowen, Brandon; Stringer, Mary T.; Hutchinson, Brian K.; Davidson, Paul C.; Gupton, Lawrence E.

2014-01-01

This report documents the updated performance characteristics of NASA Langley Research Center's (LaRC) Cockpit Motion Base (CMB) after recent revisions that were made to its inner-loop, feedback control law. The modifications to the control law will be briefly described. The performance of the Cockpit Motion Facility (CMF) will be presented. A short graphical comparison to the previous control law can be found in the appendix of this report. The revised controller will be shown to yield reduced parasitic accelerations with respect to the previous controller. Metrics based on the AGARD Advisory Report No. 144 are used to assess the overall system performance due to its recent control algorithm modification. This report also documents the standardized simulator test procedure which can be used in the future to evaluate potential updates to the control law.

Face Recognition for Access Control Systems Combining Image-Difference Features Based on a Probabilistic Model

NASA Astrophysics Data System (ADS)

Miwa, Shotaro; Kage, Hiroshi; Hirai, Takashi; Sumi, Kazuhiko

We propose a probabilistic face recognition algorithm for Access Control System(ACS)s. Comparing with existing ACSs using low cost IC-cards, face recognition has advantages in usability and security that it doesn't require people to hold cards over scanners and doesn't accept imposters with authorized cards. Therefore face recognition attracts more interests in security markets than IC-cards. But in security markets where low cost ACSs exist, price competition is important, and there is a limitation on the quality of available cameras and image control. Therefore ACSs using face recognition are required to handle much lower quality images, such as defocused and poor gain-controlled images than high security systems, such as immigration control. To tackle with such image quality problems we developed a face recognition algorithm based on a probabilistic model which combines a variety of image-difference features trained by Real AdaBoost with their prior probability distributions. It enables to evaluate and utilize only reliable features among trained ones during each authentication, and achieve high recognition performance rates. The field evaluation using a pseudo Access Control System installed in our office shows that the proposed system achieves a constant high recognition performance rate independent on face image qualities, that is about four times lower EER (Equal Error Rate) under a variety of image conditions than one without any prior probability distributions. On the other hand using image difference features without any prior probabilities are sensitive to image qualities. We also evaluated PCA, and it has worse, but constant performance rates because of its general optimization on overall data. Comparing with PCA, Real AdaBoost without any prior distribution performs twice better under good image conditions, but degrades to a performance as good as PCA under poor image conditions.

Everyday memory impairment in patients with temporal lobe epilepsy caused by hippocampal sclerosis.

PubMed

Rzezak, Patrícia; Lima, Ellen Marise; Gargaro, Ana Carolina; Coimbra, Erica; de Vincentiis, Silvia; Velasco, Tonicarlo Rodrigues; Leite, João Pereira; Busatto, Geraldo F; Valente, Kette D

2017-04-01

Patients with temporal lobe epilepsy caused by hippocampal sclerosis (TLE-HS) have episodic memory impairment. Memory has rarely been evaluated using an ecologic measure, even though performance on these tests is more related to patients' memory complaints. We aimed to measure everyday memory of patients with TLE-HS to age- and gender-matched controls. We evaluated 31 patients with TLE-HS and 34 healthy controls, without epilepsy and psychiatric disorders, using the Rivermead Behavioral Memory Test (RBMT), Visual Reproduction (WMS-III) and Logical Memory (WMS-III). We evaluated the impact of clinical variables such as the age of onset, epilepsy duration, AED use, history of status epilepticus, and seizure frequency on everyday memory. Statistical analyses were performed using MANCOVA with years of education as a confounding factor. Patients showed worse performance than controls on traditional memory tests and in the overall score of RBMT. Patients had more difficulties to recall names, a hidden belonging, to deliver a message, object recognition, to remember a story full of details, a previously presented short route, and in time and space orientation. Clinical epilepsy variables were not associated with RBMT performance. Memory span and working memory were correlated with worse performance on RBMT. Patients with TLE-HS demonstrated deficits in everyday memory functions. A standard neuropsychological battery, designed to assess episodic memory, would not evaluate these impairments. Impairment in recalling names, routes, stories, messages, and space/time disorientation can adversely impact social adaptation, and we must consider these ecologic measures with greater attention in the neuropsychological evaluation of patients with memory complaints. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Neuhauser, K.

Through discussion of five case studies (test homes), this project evaluates strategies to elevate the performance of existing homes to a level commensurate with best-in-class implementation of high-performance new construction homes. The test homes featured in this research activity participated in Deep Energy Retrofit (DER) Pilot Program sponsored by the electric and gas utility National Grid in Massachusetts and Rhode Island. Building enclosure retrofit strategies are evaluated for impact on durability and indoor air quality in addition to energy performance. Evaluation of strategies is structured around the critical control functions of water, airflow, vapor flow, and thermal control. The aimmore » of the research project is to develop guidance that could serve as a foundation for wider adoption of high performance, 'deep' retrofit work. The project will identify risk factors endemic to advanced retrofit in the context of the general building type, configuration and vintage encountered in the National Grid DER Pilot. Results for the test homes are based on observation and performance testing of recently completed projects. Additional observation would be needed to fully gauge long-term energy performance, durability, and occupant comfort.« less

Human factors engineering verification and validation for APR1400 computerized control room

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

Shin, Y. C.; Moon, H. K.; Kim, J. H.

2006-07-01

This paper introduces the Advanced Power Reactor 1400 (APR1400) HFE V and V activities the Korea Hydro Nuclear Plant Co. LTD. (KHNP) has performed for the last 10 years and some of the lessons learned through these activities. The features of APR1400 main control room include large display panel, redundant compact workstations, computer-based procedure, and safety console. Several iterations of human factors evaluations have been performed from small scale proof of concept tests to large scale integrated system tests for identifying human engineering deficiencies in the human system interface design. Evaluations in the proof of concept test were focused onmore » checking the presence of any show stopper problems in the design concept. Later evaluations were mostly for finding design problems and for assuring the resolution of human factors issues of advanced control room. The results of design evaluations were useful not only for refining the control room design, but also for licensing the standard design. Several versions of APR1400 mock-ups with dynamic simulation models of currently operating Korea Standard Nuclear Plant (KSNP) have been used for the evaluations with the participation of operators from KSNP plants. (authors)« less

ATS-6 engineering performance report. Volume:Program and systems summaries: Mechanical and thermal details

NASA Technical Reports Server (NTRS)

Wales, R. O. (Editor)

1981-01-01

The overall mission and spacecraft systems, testing, and operations are summarized. The mechanical subsystems are reviewed, encompassing mechanical design requirements; separation and deployment mechanisms; design and performance evaluation; and the television camera reflector monitor. Thermal control and contamination are discussed in terms of thermal control subsystems, design validation, subsystems performance, the advanced flight experiment, and the quartz-crystal microbalance contamination monitor.

CF6 Jet Engine Performance Improvement: High Pressure Turbine Active Clearance Control

NASA Technical Reports Server (NTRS)

Rich, S. E.; Fasching, W. A.

1982-01-01

An active clearance control system was developed which reduces fuel consumption and performance degradation. This system utilizes compressor discharge air during takeoff and fan discharge air during cruise to impinge on the shroud structure to improve the thermal response. The system was evaluated in component and engine tests. The test results demonstrated a performance improvement of 0.7 percent in cruise SFC.

A new eddy current model for magnetic bearing control system design

NASA Technical Reports Server (NTRS)

Feeley, Joseph J.; Ahlstrom, Daniel J.

1992-01-01

This paper describes a new VLSI-based controller for the implementation of a Linear-Quadratic-Gaussian (LQG) theory-based control system. Use of the controller is demonstrated by design of a controller for a magnetic bearing and its performance is evaluated by computer simulation.

Spacecraft Formation Flying Maneuvers Using Linear Quadratic Regulation With No Radial Axis Inputs

NASA Technical Reports Server (NTRS)

Starin, Scott R.; Yedavalli, R. K.; Sparks, Andrew G.; Bauer, Frank H. (Technical Monitor)

2001-01-01

Regarding multiple spacecraft formation flying, the observation has been made that control thrust need only be applied coplanar to the local horizon to achieve complete controllability of a two-satellite (leader-follower) formation. A formulation of orbital dynamics using the state of one satellite relative to another is used. Without the need for thrust along the radial (zenith-nadir) axis of the relative reference frame, propulsion system simplifications and weight reduction may be accomplished. This work focuses on the validation of this control system on its own merits, and in comparison to a related system which does provide thrust along the radial axis of the relative frame. Maneuver simulations are performed using commercial ODE solvers to propagate the Keplerian dynamics of a controlled satellite relative to an uncontrolled leader. These short maneuver simulations demonstrate the capacity of the controller to perform changes from one formation geometry to another. Control algorithm performance is evaluated based on measures such as the fuel required to complete a maneuver and the maximum acceleration required by the controller. Based on this evaluation, the exclusion of the radial axis of control still allows enough control authority to use Linear Quadratic Regulator (LQR) techniques to design a gain matrix of adequate performance over finite maneuvers. Additional simulations are conducted including perturbations and using no radial control inputs. A major conclusion presented is that control inputs along the three axes have significantly different relationships to the governing orbital dynamics that may be exploited using LQR.

ACSYNT inner loop flight control design study

NASA Technical Reports Server (NTRS)

Bortins, Richard; Sorensen, John A.

1993-01-01

The NASA Ames Research Center developed the Aircraft Synthesis (ACSYNT) computer program to synthesize conceptual future aircraft designs and to evaluate critical performance metrics early in the design process before significant resources are committed and cost decisions made. ACSYNT uses steady-state performance metrics, such as aircraft range, payload, and fuel consumption, and static performance metrics, such as the control authority required for the takeoff rotation and for landing with an engine out, to evaluate conceptual aircraft designs. It can also optimize designs with respect to selected criteria and constraints. Many modern aircraft have stability provided by the flight control system rather than by the airframe. This may allow the aircraft designer to increase combat agility, or decrease trim drag, for increased range and payload. This strategy requires concurrent design of the airframe and the flight control system, making trade-offs of performance and dynamics during the earliest stages of design. ACSYNT presently lacks means to implement flight control system designs but research is being done to add methods for predicting rotational degrees of freedom and control effector performance. A software module to compute and analyze the dynamics of the aircraft and to compute feedback gains and analyze closed loop dynamics is required. The data gained from these analyses can then be fed back to the aircraft design process so that the effects of the flight control system and the airframe on aircraft performance can be included as design metrics. This report presents results of a feasibility study and the initial design work to add an inner loop flight control system (ILFCS) design capability to the stability and control module in ACSYNT. The overall objective is to provide a capability for concurrent design of the aircraft and its flight control system, and enable concept designers to improve performance by exploiting the interrelationships between aircraft and flight control system design parameters.

Function evaluation of asphalt mixture with industrially produced BOF slag aggregate.

PubMed

Zhao, Meiling; Wu, Shaopeng; Chen, Zongwu; Li, Chao

2016-07-04

Laboratory research suggested that basic oxygen furnace (BOF) slag-based asphalt mixture was a functional material. However, the BOF slag aggregate's quality was difficult to control when it was heavily used in entity engineering. The primary objective of this research was to evaluate the functional performances of asphalt mixture containing BOF slag coarse aggregate (BSCA), which was from an industrialized production line. Limestone mixture was a control group. The Marshall method was first adopted to design asphalt mixtures. The performances of limestone asphalt mixture and BOF slag asphalt mixture including fatigue failure resistance and moisture stability were then evaluated and compared. Results showed that the asphalt mixture containing BSCA possessed better durability, which meant the quality of BSCA from industrialized production lines was well controlled and this BSCA can be heavily used in entity engineering.

A 10 cm Dual Frequency Doppler Weather Radar. Part I. The Radar System.

DTIC Science & Technology

1982-10-25

Evaluation System ( RAMCES )". The step attenuator required for this calibration can be programmed remotely, has low power and temperature coefficients, and...Control and Evaluation System". The Quality Assurance/Fault Location Network makes use of fault location techniques at critical locations in the radar and...quasi-con- tinuous monitoring of radar performance. The Radar Monitor, Control and Evaluation System provides for automated system calibration and

Polarization Control with Piezoelectric and LiNbO3 Transducers

NASA Astrophysics Data System (ADS)

Bradley, E.; Miles, E.; Loginov, B.; Vu, N.

Several Polarization control transducers have appeared on the market, and now automated, endless polarization control systems using these transducers are becoming available. Unfortunately it is not entirely clear what benchmark performance tests a polarization control system must pass, and the polarization disturbances a system must handle are open to some debate. We present quantitative measurements of realistic polarization disturbances and two benchmark tests we have successfully used to evaluate the performance of an automated, endless polarization control system. We use these tests to compare the performance of a system using piezoelectric transducers to that of a system using LiNbO3 transducers.

77 FR 58767 - Definitions Relating to Electronic Orders and Prescriptions for Controlled Substances

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-24

... of Certified Public Accountants (AICPA) Statement of Auditing Standards (SAS) 70 criteria. Signing... professional service performed by a qualified certified public accountant to evaluate one or more aspects of... performed by a qualified certified public accountant to evaluate one or more aspects of Web sites. [75 FR...

Performance evaluation of traffic sensing and control devices : [technical summary].

DOT National Transportation Integrated Search

2011-01-01

High quality sensing and control systems are essential for providing efficient signalized arterial operations. INDOT operates over 2600 traffic signal controllers, approximately 2000 of which use some form of vehicle detection. The private sector con...

[Comparison between the diagnosis of attention deficit hyperactivity disorder with the DSM-5 and neuropsychological evaluation of the executive functions].

PubMed

Abad-Mas, L; Caloca-Catala, O; Mulas, F; Ruiz-Andres, R

2017-02-24

The attention deficit-hyperactivity disorder (ADHD) has a prevalence among 3-7% in scholar population and it is associated with learning disabilities and executive dysfunctions. To study the relationship between the ADHD diagnostic through DSM-5 criteria and the neuropshychology evaluation of executive functions. The sample of this study consisted in 50 subjects, 12 females and 38 males, with an age between 8 and 10 years old. To evaluate the inhibitory control, we used the Stroop Test and the Continuous Performance Test (CPT), to evaluate intelligence and working memory we use the Wechsler Intelligence Scale WISC-IV, to evaluate attention we used the CPT and Selective Attention Test. There weren't significant differences between both subtypes of ADHD regarding working memory, on the other hand the female group had better abilities in cognitive flexibility task than males and subjects diagnosed with combined ADHD had more difficulties in inhibitory control. We can confirm that the definition of ADHD in DSM-5 isn't enough as them are imprecise. Therefore, the disease definition it's performed by a specific evaluation of attention and inhibitory control mechanisms and its necessary a neuropshychological evaluation of these brain functions.

Evaluating performance of risk identification methods through a large-scale simulation of observational data.

PubMed

Ryan, Patrick B; Schuemie, Martijn J

2013-10-01

There has been only limited evaluation of statistical methods for identifying safety risks of drug exposure in observational healthcare data. Simulations can support empirical evaluation, but have not been shown to adequately model the real-world phenomena that challenge observational analyses. To design and evaluate a probabilistic framework (OSIM2) for generating simulated observational healthcare data, and to use this data for evaluating the performance of methods in identifying associations between drug exposure and health outcomes of interest. Seven observational designs, including case-control, cohort, self-controlled case series, and self-controlled cohort design were applied to 399 drug-outcome scenarios in 6 simulated datasets with no effect and injected relative risks of 1.25, 1.5, 2, 4, and 10, respectively. Longitudinal data for 10 million simulated patients were generated using a model derived from an administrative claims database, with associated demographics, periods of drug exposure derived from pharmacy dispensings, and medical conditions derived from diagnoses on medical claims. Simulation validation was performed through descriptive comparison with real source data. Method performance was evaluated using Area Under ROC Curve (AUC), bias, and mean squared error. OSIM2 replicates prevalence and types of confounding observed in real claims data. When simulated data are injected with relative risks (RR) ≥ 2, all designs have good predictive accuracy (AUC > 0.90), but when RR < 2, no methods achieve 100 % predictions. Each method exhibits a different bias profile, which changes with the effect size. OSIM2 can support methodological research. Results from simulation suggest method operating characteristics are far from nominal properties.

Improved methodology to assess modification and completion of landfill gas management in the aftercare period

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

Morris, Jeremy W.F., E-mail: jmorris@geosyntec.com; Crest, Marion, E-mail: marion.crest@suez-env.com; Barlaz, Morton A., E-mail: barlaz@ncsu.edu

Highlights: Black-Right-Pointing-Pointer Performance-based evaluation of landfill gas control system. Black-Right-Pointing-Pointer Analytical framework to evaluate transition from active to passive gas control. Black-Right-Pointing-Pointer Focus on cover oxidation as an alternative means of passive gas control. Black-Right-Pointing-Pointer Integrates research on long-term landfill behavior with practical guidance. - Abstract: Municipal solid waste landfills represent the dominant option for waste disposal in many parts of the world. While some countries have greatly reduced their reliance on landfills, there remain thousands of landfills that require aftercare. The development of cost-effective strategies for landfill aftercare is in society's interest to protect human health and the environmentmore » and to prevent the emergence of landfills with exhausted aftercare funding. The Evaluation of Post-Closure Care (EPCC) methodology is a performance-based approach in which landfill performance is assessed in four modules including leachate, gas, groundwater, and final cover. In the methodology, the objective is to evaluate landfill performance to determine when aftercare monitoring and maintenance can be reduced or possibly eliminated. This study presents an improved gas module for the methodology. While the original version of the module focused narrowly on regulatory requirements for control of methane migration, the improved gas module also considers best available control technology for landfill gas in terms of greenhouse gas emissions, air quality, and emissions of odoriferous compounds. The improved module emphasizes the reduction or elimination of fugitive methane by considering the methane oxidation capacity of the cover system. The module also allows for the installation of biologically active covers or other features designed to enhance methane oxidation. A methane emissions model, CALMIM, was used to assist with an assessment of the methane oxidation capacity of landfill covers.« less

Evaluation of the performance of statistical tests used in making cleanup decisions at Superfund sites. Part 1: Choosing an appropriate statistical test

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

Berman, D.W.; Allen, B.C.; Van Landingham, C.B.

1998-12-31

The decision rules commonly employed to determine the need for cleanup are evaluated both to identify conditions under which they lead to erroneous conclusions and to quantify the rate that such errors occur. Their performance is also compared with that of other applicable decision rules. The authors based the evaluation of decision rules on simulations. Results are presented as power curves. These curves demonstrate that the degree of statistical control achieved is independent of the form of the null hypothesis. The loss of statistical control that occurs when a decision rule is applied to a data set that does notmore » satisfy the rule`s validity criteria is also clearly demonstrated. Some of the rules evaluated do not offer the formal statistical control that is an inherent design feature of other rules. Nevertheless, results indicate that such informal decision rules may provide superior overall control of error rates, when their application is restricted to data exhibiting particular characteristics. The results reported here are limited to decision rules applied to uncensored and lognormally distributed data. To optimize decision rules, it is necessary to evaluate their behavior when applied to data exhibiting a range of characteristics that bracket those common to field data. The performance of decision rules applied to data sets exhibiting a broader range of characteristics is reported in the second paper of this study.« less

Study of automatic and manual terminal guidance and control systems for space shuttle vehicles. Volume 2: Section 4 through appendix B

NASA Technical Reports Server (NTRS)

Osder, S.; Keller, R.

1971-01-01

Guidance and control design studies that were performed for three specific space shuttle candidate vehicles are described. Three types of simulation were considered. The manual control investigations and pilot evaluations of the automatic system performance is presented. Recommendations for systems and equipment, both airborne and ground-based, necessary to flight test the guidance and control concepts for shuttlecraft terminal approach and landing are reported.

Evaluation and characterization of the methane-carbon dioxide decomposition reaction

NASA Technical Reports Server (NTRS)

Davenport, R. J.; Schubert, F. H.; Shumar, J. W.; Steenson, T. S.

1975-01-01

A program was conducted to evaluate and characterize the carbon dioxide-methane (CO2-CH4) decomposition reaction, i.e., CO2 + CH4 = 2C + 2H2O. The primary objective was to determine the feasibility of applying this reaction at low temperatures as a technique for recovering the oxygen (O2) remaining in the CO2 which exits mixed with CH4 from a Sabatier CO2 reduction subsystem (as part of an air revitalization system of a manned spacecraft). A test unit was designed, fabricated, and assembled for characterizing the performance of various catalysts for the reaction and ultraviolet activation of the CH4 and CO2. The reactor included in the test unit was designed to have sufficient capacity to evaluate catalyst charges of up to 76 g (0.17 lb). The test stand contained the necessary instrumentation and controls to obtain the data required to characterize the performance of the catalysts and sensitizers tested: flow control and measurement, temperature control and measurement, product and inlet gas analysis, and pressure measurement. A product assurance program was performed implementing the concepts of quality control and safety into the program effort.

TREATMENT PLANT EVALUATION FOR PARTICULATE CONTAMINANT REMOVAL

EPA Science Inventory

A general procedure is suggested for evaluating performance of water filtration plants. Plant operating records should be reviewed. Plant hydraulics should be evaluated. Chemical feed pumps, measuring, and additional points, plus control of chemical doses, are discussed. Rapid mi...

A software control system for the ACTS high-burst-rate link evaluation terminal

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Daugherty, Elaine S.

1991-01-01

Control and performance monitoring of NASA's High Burst Rate Link Evaluation Terminal (HBR-LET) is accomplished by using several software control modules. Different software modules are responsible for controlling remote radio frequency (RF) instrumentation, supporting communication between a host and a remote computer, controlling the output power of the Link Evaluation Terminal and data display. Remote commanding of microwave RF instrumentation and the LET digital ground terminal allows computer control of various experiments, including bit error rate measurements. Computer communication allows system operators to transmit and receive from the Advanced Communications Technology Satellite (ACTS). Finally, the output power control software dynamically controls the uplink output power of the terminal to compensate for signal loss due to rain fade. Included is a discussion of each software module and its applications.

Definition and evaluation of the data-link layer of PACnet

NASA Astrophysics Data System (ADS)

Alsafadi, Yasser H.; Martinez, Ralph; Sanders, William H.

1991-07-01

PACnet is a 200-500 Mbps dual-ring fiber optic network designed to implement a picture archiving and communication system (PACS) in a hospital environment. The network consists of three channels: an image transfer channel, a command and control channel, and a real-time data channel. An initial network interface unit (NIU) design for PACnet consisted of a functional description of the protocols and NIU major components. In order to develop a demonstration prototype, additional definition of protocol algorithms of each channel is necessary. Using the International Standards Organization/Open Systems Interconnection (ISO/OSI) reference model as a guide, the definition of the data link layer is extended. This definition covers interface service specifications for the two constituent sublayers: logical link control (LLC) and medium access control (MAC). Furthermore, it describes procedures for data transfer, mechanisms of error detection and fault recovery. A performance evaluation study was then made to determine how the network performs under various application scenarios. The performance evaluation study was performed using stochastic activity networks, which can formally describe the network behavior. The results of the study demonstrate the feasibility of PACnet as an integrated image, data, and voice network for PACS.

Effects of sand sagebrush control in southern mixed-grass prairie rangeland on cattle performance and economic return

USDA-ARS?s Scientific Manuscript database

To evaluate the effects of sand sagebrush (Artemisia filifolia Torr.) control in native rangelands on cattle performance, 15 pastures (10 to 21 ha each) were selected in Northwest Oklahoma. Eleven pastures had been sprayed with 2,4-dichlorophenoxyacetic acid in 1984 or 2003 to establish differences...

Greenhouse production of Impatiens wallerana using a controlled-release fertiliser produces quality finished plants with enhanced garden performance

USDA-ARS?s Scientific Manuscript database

Nutrient management during production can greatly influence post-production quality of plants. The objective of this research was to evaluate the effect of controlled release fertilizer (CRF) applied at the time of plug planting on the garden performance (post-production) of impatiens (Impatiens wal...

Development of a Self-Balancing Human Transportation Vehicle for the Teaching of Feedback Control

ERIC Educational Resources Information Center

Lin, Shui-Chun; Tsai, Ching-Chih

2009-01-01

Control systems education often needs to design interesting hands-on exercises that keep students interested in the control theory presented in lectures. These exercises include system modeling, system analyses, controller syntheses, implementation, experimentation, and performance evaluation of a control system. This paper presents an interesting…

Subsonic flight test evaluation of a propulsion system parameter estimation process for the F100 engine

NASA Technical Reports Server (NTRS)

Orme, John S.; Gilyard, Glenn B.

1992-01-01

Integrated engine-airframe optimal control technology may significantly improve aircraft performance. This technology requires a reliable and accurate parameter estimator to predict unmeasured variables. To develop this technology base, NASA Dryden Flight Research Facility (Edwards, CA), McDonnell Aircraft Company (St. Louis, MO), and Pratt & Whitney (West Palm Beach, FL) have developed and flight-tested an adaptive performance seeking control system which optimizes the quasi-steady-state performance of the F-15 propulsion system. This paper presents flight and ground test evaluations of the propulsion system parameter estimation process used by the performance seeking control system. The estimator consists of a compact propulsion system model and an extended Kalman filter. The extended Laman filter estimates five engine component deviation parameters from measured inputs. The compact model uses measurements and Kalman-filter estimates as inputs to predict unmeasured propulsion parameters such as net propulsive force and fan stall margin. The ability to track trends and estimate absolute values of propulsion system parameters was demonstrated. For example, thrust stand results show a good correlation, especially in trends, between the performance seeking control estimated and measured thrust.

Subsonic flight test evaluation of a performance seeking control algorithm on an F-15 airplane

NASA Technical Reports Server (NTRS)

Gilyard, Glenn B.; Orme, John S.

1992-01-01

The subsonic flight test evaluation phase of the NASA F-15 (powered by F 100 engines) performance seeking control program was completed for single-engine operation at part- and military-power settings. The subsonic performance seeking control algorithm optimizes the quasi-steady-state performance of the propulsion system for three modes of operation. The minimum fuel flow mode minimizes fuel consumption. The minimum thrust mode maximizes thrust at military power. Decreases in thrust-specific fuel consumption of 1 to 2 percent were measured in the minimum fuel flow mode; these fuel savings are significant, especially for supersonic cruise aircraft. Decreases of up to approximately 100 degree R in fan turbine inlet temperature were measured in the minimum temperature mode. Temperature reductions of this magnitude would more than double turbine life if inlet temperature was the only life factor. Measured thrust increases of up to approximately 15 percent in the maximum thrust mode cause substantial increases in aircraft acceleration. The system dynamics of the closed-loop algorithm operation were good. The subsonic flight phase has validated the performance seeking control technology, which can significantly benefit the next generation of fighter and transport aircraft.

Effects of Relaxing Music on Mental Fatigue Induced by a Continuous Performance Task: Behavioral and ERPs Evidence.

PubMed

Guo, Wei; Ren, Jie; Wang, Biye; Zhu, Qin

2015-01-01

The purpose of this study was to investigate whether listening to relaxing music would help reduce mental fatigue and to maintain performance after a continuous performance task. The experiment involved two fatigue evaluation phases carried out before and after a fatigue inducing phase. A 1-hour AX-continuous performance test was used to induce mental fatigue in the fatigue-inducing phase, and participants' subjective evaluation on the mental fatigue, as well as their neurobehavioral performance in a Go/NoGo task, were measured before and after the fatigue-inducing phase. A total of 36 undergraduate students (18-22 years) participated in the study and were randomly assigned to the music group and control group. The music group performed the fatigue-inducing task while listening to relaxing music, and the control group performed the same task without any music. Our results revealed that after the fatigue-inducing phase, (a) the music group demonstrated significantly less mental fatigue than control group, (b) reaction time significantly increased for the control group but not for the music group, (c) larger Go-P3 and NoGo-P3 amplitudes were observed in the music group, although larger NoGo-N2 amplitudes were detected for both groups. These results combined to suggest that listening to relaxing music alleviated the mental fatigue associated with performing an enduring cognitive-motor task.

Characteristics of On-Road Driving Performance of Persons With Central Vision Loss Who Use Bioptic Telescopes

PubMed Central

Wood, Joanne M.; McGwin, Gerald; Elgin, Jennifer; Searcey, Karen; Owsley, Cynthia

2013-01-01

Purpose. To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls. Methods. Participants included 23 persons (mean age = 33 ± 12 years) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a state bioptic driving program, and 23 visually normal age-matched controls (mean age = 33 ± 12 years). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection, and frequency of bioptic telescope use. Results. Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls. Conclusions. Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation. PMID:23640044

Neural network-based model reference adaptive control system.

PubMed

Patino, H D; Liu, D

2000-01-01

In this paper, an approach to model reference adaptive control based on neural networks is proposed and analyzed for a class of first-order continuous-time nonlinear dynamical systems. The controller structure can employ either a radial basis function network or a feedforward neural network to compensate adaptively the nonlinearities in the plant. A stable controller-parameter adjustment mechanism, which is determined using the Lyapunov theory, is constructed using a sigma-modification-type updating law. The evaluation of control error in terms of the neural network learning error is performed. That is, the control error converges asymptotically to a neighborhood of zero, whose size is evaluated and depends on the approximation error of the neural network. In the design and analysis of neural network-based control systems, it is important to take into account the neural network learning error and its influence on the control error of the plant. Simulation results showing the feasibility and performance of the proposed approach are given.

Proceedings of the Conference on the Design of Experiments in Army Research, Development, and Testing (33rd)

DTIC Science & Technology

1988-05-01

Evaluation Directorate (ARMTE) was tasked to conduct a "side- by-side" comparison of EMPS vs . DATMs and to conduct a human factors evaluation of the EMPS...performance ("side-by-side") comparison of EMPS vs . DATMs and to conduct a human factors evaluation. The performance evaluation was based on the speed... independent targets over time. To acquire data for this research, the BRL conducted a statistically designed exper- iment, the Firepower Control Experiment

A study to assess the long-term stability of the ionization chamber reference system in the LNMRI

NASA Astrophysics Data System (ADS)

Trindade Filho, O. L.; Conceição, D. A.; da Silva, C. J.; Delgado, J. U.; de Oliveira, A. E.; Iwahara, A.; Tauhata, L.

2018-03-01

Ionization chambers are used as secondary standard in order to maintain the calibration factors of radionuclides in the activity measurements in metrology laboratories. Used as radionuclide calibrator in nuclear medicine clinics to control dose in patients, its long-term performance is not evaluated systematically. A methodology for long-term evaluation for its stability is monitored and checked. Historical data produced monthly of 2012 until 2017, by an ionization chamber, electrometer and 226Ra, were analyzed via control chart, aiming to follow the long-term performance. Monitoring systematic errors were consistent within the limits of control, demonstrating the quality of measurements in compliance with ISO17025.

Digital autopilots: Design considerations and simulator evaluations

NASA Technical Reports Server (NTRS)

Osder, S.; Neuman, F.; Foster, J.

1971-01-01

The development of a digital autopilot program for a transport aircraft and the evaluation of that system's performance on a transport aircraft simulator is discussed. The digital autopilot includes three axis attitude stabilization, automatic throttle control and flight path guidance functions with emphasis on the mode progression from descent into the terminal area through automatic landing. The study effort involved a sequence of tasks starting with the definition of detailed system block diagrams of control laws followed by a flow charting and programming phase and concluding with performance verification using the transport aircraft simulation. The autopilot control laws were programmed in FORTRAN 4 in order to isolate the design process from requirements peculiar to an individual computer.

A performance analysis method for distributed real-time robotic systems: A case study of remote teleoperation

NASA Technical Reports Server (NTRS)

Lefebvre, D. R.; Sanderson, A. C.

1994-01-01

Robot coordination and control systems for remote teleoperation applications are by necessity implemented on distributed computers. Modeling and performance analysis of these distributed robotic systems is difficult, but important for economic system design. Performance analysis methods originally developed for conventional distributed computer systems are often unsatisfactory for evaluating real-time systems. The paper introduces a formal model of distributed robotic control systems; and a performance analysis method, based on scheduling theory, which can handle concurrent hard-real-time response specifications. Use of the method is illustrated by a case of remote teleoperation which assesses the effect of communication delays and the allocation of robot control functions on control system hardware requirements.

Integrated modeling and analysis of a space-truss article

NASA Technical Reports Server (NTRS)

Stockwell, Alan E.; Perez, Sharon E.; Pappa, Richard S.

1990-01-01

MSC/NASTRAN is being used in the Controls-Structures Interaction (CSI) program at NASA Langley Research Center as a key analytical tool for structural analysis as well as the basis for control law development, closed-loop performance evaluation, and system safety checks. Guest investigators from academia and industry are performing dynamics and control experiments on a flight-like deployable space truss called Mini-Mast to determine the effectiveness of various active-vibration control laws. MSC/NASTRAN was used to calculate natural frequencies and mode shapes below 100 Hz to describe the dynamics of the 20-meter-long lightweight Mini-Mast structure. Gravitational effects contribute significantly to structural stiffness and are accounted for through a two-phase solution in which the differential stiffness matrix is calculated and then used in the eigensolution. Reduced modal models are extracted for control law design and evaluation of closed-loop system performance. Predicted actuator forces from controls simulations are then applied to the extended model to predict member loads and stresses. These pre-test analyses reduce risks associated with the structural integrity of the test article, which is a major concern in closed-loop control experiments due to potential instabilities.

Evaluation of the leap motion controller as a new contact-free pointing device.

PubMed

Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

2014-12-24

This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8% for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC.

Evaluation of the Leap Motion Controller as a New Contact-Free Pointing Device

PubMed Central

Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

2015-01-01

This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8 % for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC. PMID:25609043

Reliability issues in active control of large flexible space structures

NASA Technical Reports Server (NTRS)

Vandervelde, W. E.

1986-01-01

Efforts in this reporting period were centered on four research tasks: design of failure detection filters for robust performance in the presence of modeling errors, design of generalized parity relations for robust performance in the presence of modeling errors, design of failure sensitive observers using the geometric system theory of Wonham, and computational techniques for evaluation of the performance of control systems with fault tolerance and redundancy management

Seismic Performance Evaluation of Reinforced Concrete Frames Subjected to Seismic Loads

NASA Astrophysics Data System (ADS)

Zameeruddin, Mohd.; Sangle, Keshav K.

2017-06-01

Ten storied-3 bays reinforced concrete bare frame designed for gravity loads following the guidelines of IS 456 and IS 13920 for ductility is subjected to seismic loads. The seismic demands on this building were calculated by following IS 1893 for response spectra of 5% damping (for hard soil type). Plastic hinges were assigned to the beam and column at both ends to represent the failure mode, when member yields. Non-linear static (pushover) analysis was performed to evaluate the performance of the building in reference to first (ATC 40), second (FEMA 356) and next-generation (FEMA 440) performance based seismic design procedures. Base shear against top displacement curve of structure, known as pushover curve was obtained for two actions of plastic hinge behavior, force-controlled (brittle) and deformation-controlled (ductile) actions. Lateral deformation corresponding to performance point proves the building capability to sustain a certain level of seismic loads. The failure is represented by a sequence of formation of plastic hinges. Deformation-controlled action of hinges showed that building behaves like strong-column-weak-beam mechanism, whereas force-controlled action showed formation of hinges in the column. The study aims to understand the first, second and next generation performance based design procedure in prediction of actual building responses and their conservatism into the acceptance criteria.

On the estimation algorithm used in adaptive performance optimization of turbofan engines

NASA Technical Reports Server (NTRS)

Espana, Martin D.; Gilyard, Glenn B.

1993-01-01

The performance seeking control algorithm is designed to continuously optimize the performance of propulsion systems. The performance seeking control algorithm uses a nominal model of the propulsion system and estimates, in flight, the engine deviation parameters characterizing the engine deviations with respect to nominal conditions. In practice, because of measurement biases and/or model uncertainties, the estimated engine deviation parameters may not reflect the engine's actual off-nominal condition. This factor has a necessary impact on the overall performance seeking control scheme exacerbated by the open-loop character of the algorithm. The effects produced by unknown measurement biases over the estimation algorithm are evaluated. This evaluation allows for identification of the most critical measurements for application of the performance seeking control algorithm to an F100 engine. An equivalence relation between the biases and engine deviation parameters stems from an observability study; therefore, it is undecided whether the estimated engine deviation parameters represent the actual engine deviation or whether they simply reflect the measurement biases. A new algorithm, based on the engine's (steady-state) optimization model, is proposed and tested with flight data. When compared with previous Kalman filter schemes, based on local engine dynamic models, the new algorithm is easier to design and tune and it reduces the computational burden of the onboard computer.

A benchmark for fault tolerant flight control evaluation

NASA Astrophysics Data System (ADS)

Smaili, H.; Breeman, J.; Lombaerts, T.; Stroosma, O.

2013-12-01

A large transport aircraft simulation benchmark (REconfigurable COntrol for Vehicle Emergency Return - RECOVER) has been developed within the GARTEUR (Group for Aeronautical Research and Technology in Europe) Flight Mechanics Action Group 16 (FM-AG(16)) on Fault Tolerant Control (2004 2008) for the integrated evaluation of fault detection and identification (FDI) and reconfigurable flight control strategies. The benchmark includes a suitable set of assessment criteria and failure cases, based on reconstructed accident scenarios, to assess the potential of new adaptive control strategies to improve aircraft survivability. The application of reconstruction and modeling techniques, based on accident flight data, has resulted in high-fidelity nonlinear aircraft and fault models to evaluate new Fault Tolerant Flight Control (FTFC) concepts and their real-time performance to accommodate in-flight failures.

Family incivility and job performance: a moderated mediation model of psychological distress and core self-evaluation.

PubMed

Lim, Sandy; Tai, Kenneth

2014-03-01

This study extends the stress literature by exploring the relationship between family incivility and job performance. We examine whether psychological distress mediates the link between family incivility and job performance. We also investigate how core self-evaluation might moderate this mediated relationship. Data from a 2-wave study indicate that psychological distress mediates the relationship between family incivility and job performance. In addition, core self-evaluation moderates the relationship between family incivility and psychological distress but not the relationship between psychological distress and job performance. The results hold while controlling for general job stress, family-to-work conflict, and work-to-family conflict. The findings suggest that family incivility is linked to poor performance at work, and psychological distress and core self-evaluation are key mechanisms in the relationship.

Implementation of Insight Responsibilities in Process Engineering

NASA Technical Reports Server (NTRS)

Osborne, Deborah M.

1997-01-01

This report describes an approach for evaluating flight readiness (COFR) and contractor performance evaluation (award fee) as part of the insight role of NASA Process Engineering at Kennedy Space Center. Several evaluation methods are presented, including systems engineering evaluations and use of systems performance data. The transition from an oversight function to the insight function is described. The types of analytical tools appropriate for achieving the flight readiness and contractor performance evaluation goals are described and examples are provided. Special emphasis is placed upon short and small run statistical quality control techniques. Training requirements for system engineers are delineated. The approach described herein would be equally appropriate in other directorates at Kennedy Space Center.

Asymmetric balance control between legs for quiet but not for perturbed stance.

PubMed

Vieira, Osvaldo; Coelho, Daniel Boari; Teixeira, Luis Augusto

2014-10-01

Interlateral performance asymmetry in upright balance control was evaluated in this investigation by comparing unipedal stance on the right versus the left leg. Participants were healthy young adults, hand-foot congruent preference for the right body side. Balance performance was evaluated in unperturbed quiet stance and in the recovery of balance stability following a mechanical perturbation induced by unexpected load release. Evaluation was made under availability of full sensory information, and under deprivation of vision combined with distortion of sensory inputs from the feet soles. Results from perturbed posture revealed that muscular response latency and postural sway were symmetric between the legs. Unipedal stance was more stable when the body was supported on the right as compared with the left leg. No interaction was found between leg and sensory condition. Our findings are interpreted as resulting from specialization of the sensorimotor system controlling the right leg for continuous low-magnitude postural adjustments, while corrections to large-scale stance sway are symmetrically controlled between body sides.

Microgravity isolation system design: A modern control analysis framework

NASA Technical Reports Server (NTRS)

Hampton, R. D.; Knospe, C. R.; Allaire, P. E.; Grodsinsky, C. M.

1994-01-01

Many acceleration-sensitive, microgravity science experiments will require active vibration isolation from the manned orbiters on which they will be mounted. The isolation problem, especially in the case of a tethered payload, is a complex three-dimensional one that is best suited to modern-control design methods. These methods, although more powerful than their classical counterparts, can nonetheless go only so far in meeting the design requirements for practical systems. Once a tentative controller design is available, it must still be evaluated to determine whether or not it is fully acceptable, and to compare it with other possible design candidates. Realistically, such evaluation will be an inherent part of a necessary iterative design process. In this paper, an approach is presented for applying complex mu-analysis methods to a closed-loop vibration isolation system (experiment plus controller). An analysis framework is presented for evaluating nominal stability, nominal performance, robust stability, and robust performance of active microgravity isolation systems, with emphasis on the effective use of mu-analysis methods.

Strategic performance evaluation in cancer centers.

PubMed

Delgado, Rigoberto I; Langabeer, James R

2009-01-01

Most research in healthcare strategy has focused on formulating or implementing organizational plans and strategies, and little attention has been dedicated to the post-implementation control and evaluation of strategy, which we contend is the most critical aspect of achieving organizational goals. The objective of this study was to identify strategic control approaches used by major cancer centers in the country and to relate these practices to financial performance. Our intent was to expand the theory and practice of healthcare strategy to focused services, such as oncology. We designed a 17-question survey to capture elements of strategy and performance from our study sample, which comprised major cancer hospitals in the United States and shared similar mandates and resource constraints. The results suggest that high-performing cancer centers use more sophisticated analytical approaches, invest greater financial resources in performance analysis, and conduct more frequent performance reviews than do low-performing organizations. Our conclusions point to the need for a more robust approach to strategic assessment. In this article, we offer a number of recommendations for management to achieve strategic plans and goals on the basis of our research. To our knowledge, this study is one of the first to concentrate on the area of strategic control.

Solid polymer electrolyte (SPE) fuel cell technology program, phase 2/2A. [testing and evaluations

NASA Technical Reports Server (NTRS)

1976-01-01

Test evaluations were performed on a fabricated single solid polymer electrolyte cell unit. The cell operated at increased current density and at higher performance levels. This improved performance was obtained through a combination of increased temperature, increased reactant pressures, improved activation techniques and improved thermal control over the baseline cell configuration. The cell demonstrated a higher acid content membrane which resulted in increased performance. Reduced catalyst loading and low cost membrane development showed encouraging results.

Model-centric distribution automation: Capacity, reliability, and efficiency

DOE PAGES

Onen, Ahmet; Jung, Jaesung; Dilek, Murat; ...

2016-02-26

A series of analyses along with field validations that evaluate efficiency, reliability, and capacity improvements of model-centric distribution automation are presented. With model-centric distribution automation, the same model is used from design to real-time control calculations. A 14-feeder system with 7 substations is considered. The analyses involve hourly time-varying loads and annual load growth factors. Phase balancing and capacitor redesign modifications are used to better prepare the system for distribution automation, where the designs are performed considering time-varying loads. Coordinated control of load tap changing transformers, line regulators, and switched capacitor banks is considered. In evaluating distribution automation versus traditionalmore » system design and operation, quasi-steady-state power flow analysis is used. In evaluating distribution automation performance for substation transformer failures, reconfiguration for restoration analysis is performed. In evaluating distribution automation for storm conditions, Monte Carlo simulations coupled with reconfiguration for restoration calculations are used. As a result, the evaluations demonstrate that model-centric distribution automation has positive effects on system efficiency, capacity, and reliability.« less

Model-centric distribution automation: Capacity, reliability, and efficiency

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

Onen, Ahmet; Jung, Jaesung; Dilek, Murat

A series of analyses along with field validations that evaluate efficiency, reliability, and capacity improvements of model-centric distribution automation are presented. With model-centric distribution automation, the same model is used from design to real-time control calculations. A 14-feeder system with 7 substations is considered. The analyses involve hourly time-varying loads and annual load growth factors. Phase balancing and capacitor redesign modifications are used to better prepare the system for distribution automation, where the designs are performed considering time-varying loads. Coordinated control of load tap changing transformers, line regulators, and switched capacitor banks is considered. In evaluating distribution automation versus traditionalmore » system design and operation, quasi-steady-state power flow analysis is used. In evaluating distribution automation performance for substation transformer failures, reconfiguration for restoration analysis is performed. In evaluating distribution automation for storm conditions, Monte Carlo simulations coupled with reconfiguration for restoration calculations are used. As a result, the evaluations demonstrate that model-centric distribution automation has positive effects on system efficiency, capacity, and reliability.« less

Analytic derivation and evaluation of a state-trajectory control law for dc-to-dc converters

NASA Technical Reports Server (NTRS)

Burns, W. W., III; Wilson, T. G.

1977-01-01

Mathematical representations of a state-plane switching boundary employed in a state-trajectory control law for dc-to-dc converters are derived. Several levels of approximation to the switching boundary equations are presented, together with an evaluation of the effects of nonideal operating characteristics of converter power stage components on the shape and location of the boundary and the behavior of a system controlled by it. Digital computer simulations of dc-to-dc converters operating in conjunction with each of these levels of control are presented and evaluated with respect to changes in transient and steady-state performance.

Summary of Federal Aviation Administration Responses to National Transportation Safety Board Safety Recommendations.

DTIC Science & Technology

1982-01-01

A-81-154. A-81-155. Adopt procedures and directives to use the student evaluations prepared by academic personnel at the FAA controller training...density ATC facilities. This determination, which is based on academic evaluations and the performance of the trainee in the radar training facility...81-154) Adopt procedures and directives to use the student evaluations prepared by academic personnel at the FAA controller training center as a

Evaluation of the performance of accelerometer-based gait event detection algorithms in different real-world scenarios using the MAREA gait database.

PubMed

Khandelwal, Siddhartha; Wickström, Nicholas

2017-01-01

Numerous gait event detection (GED) algorithms have been developed using accelerometers as they allow the possibility of long-term gait analysis in everyday life. However, almost all such existing algorithms have been developed and assessed using data collected in controlled indoor experiments with pre-defined paths and walking speeds. On the contrary, human gait is quite dynamic in the real-world, often involving varying gait speeds, changing surfaces and varying surface inclinations. Though portable wearable systems can be used to conduct experiments directly in the real-world, there is a lack of publicly available gait datasets or studies evaluating the performance of existing GED algorithms in various real-world settings. This paper presents a new gait database called MAREA (n=20 healthy subjects) that consists of walking and running in indoor and outdoor environments with accelerometers positioned on waist, wrist and both ankles. The study also evaluates the performance of six state-of-the-art accelerometer-based GED algorithms in different real-world scenarios, using the MAREA gait database. The results reveal that the performance of these algorithms is inconsistent and varies with changing environments and gait speeds. All algorithms demonstrated good performance for the scenario of steady walking in a controlled indoor environment with a combined median F1score of 0.98 for Heel-Strikes and 0.94 for Toe-Offs. However, they exhibited significantly decreased performance when evaluated in other lesser controlled scenarios such as walking and running in an outdoor street, with a combined median F1score of 0.82 for Heel-Strikes and 0.53 for Toe-Offs. Moreover, all GED algorithms displayed better performance for detecting Heel-Strikes as compared to Toe-Offs, when evaluated in different scenarios. Copyright © 2016 Elsevier B.V. All rights reserved.

Attitude control study for a large flexible spacecraft using a Solar Electric Propulsion System (SEPS)

NASA Technical Reports Server (NTRS)

Tolivar, A. F.; Key, R. W.

1980-01-01

The attitude control performance of the solar electric propulsion system (SEPS) was evaluated. A thrust vector control system for powered flight control was examined along with a gas jet reaction control system, and a reaction wheel system, both of which have been proposed for nonpowered flight control. Comprehensive computer simulations of each control system were made and evaluated using a 30 mode spacecraft model. Results obtained indicate that thrust vector control and reaction wheel systems offer acceptable smooth proportional control. The gas jet control system is shown to be risky for a flexible structure such as SEPS, and is therefore, not recommended as a primary control method.

Emotional Learning Based Intelligent Controllers for Rotor Flux Oriented Control of Induction Motor

NASA Astrophysics Data System (ADS)

Abdollahi, Rohollah; Farhangi, Reza; Yarahmadi, Ali

2014-08-01

This paper presents design and evaluation of a novel approach based on emotional learning to improve the speed control system of rotor flux oriented control of induction motor. The controller includes a neuro-fuzzy system with speed error and its derivative as inputs. A fuzzy critic evaluates the present situation, and provides the emotional signal (stress). The controller modifies its characteristics so that the critics stress is reduced. The comparative simulation results show that the proposed controller is more robust and hence found to be a suitable replacement of the conventional PI controller for the high performance industrial drive applications.

Installation of active noise control and active vibration control on a GP40-2 locomotive : final report.

DOT National Transportation Integrated Search

2016-06-01

This project evaluated the performance of active noise control (ANC) and active vibration control (AVC) technologies using a GP40-2 locomotive located at the Transportation Technology Center (TTC) near Pueblo, CO, to determine the applicability of AN...

CSM digital autopilot testing in support of ASTP experiments control requirements

NASA Technical Reports Server (NTRS)

Rue, D. L.

1975-01-01

Results are presented of CSM digital autopilot (DAP) testing. The testing was performed to demonstrate and evaluate control modes which are currently planned or could be considered for use in support of experiments on the ASTP mission. The testing was performed on the Lockheed Guidance, Navigation, and Control System Functional Simulator (GNCFS). This simulator, which was designed to test the Apollo and Skylab DAP control system, has been used extensively and is a proven tool for CSM DAP analysis.

Development of High Fidelity Mobility Simulation of an Autonomous Vehicle in an Off-Road Scenario Using Integrated Sensor, Controller, and Multi-Body Dynamics

DTIC Science & Technology

2011-08-01

VEHICLE IN AN OFF-ROAD SCENARIO USING INTEGRATED SENSOR, CONTROLLER, AND MULTI-BODY DYNAMICS Paramsothy Jayakumar , PhD William Smith US Army...environment for a control system, mechanical system dynamics , and sensor simulation for an improved assessment of the vehicle system performance...improve vehicle dynamic performance; we must also evaluate and improve the sensor suite employed on the vehicle, and the controller used to operate

A unified method for evaluating real-time computer controllers: A case study. [aircraft control

NASA Technical Reports Server (NTRS)

Shin, K. G.; Krishna, C. M.; Lee, Y. H.

1982-01-01

A real time control system consists of a synergistic pair, that is, a controlled process and a controller computer. Performance measures for real time controller computers are defined on the basis of the nature of this synergistic pair. A case study of a typical critical controlled process is presented in the context of new performance measures that express the performance of both controlled processes and real time controllers (taken as a unit) on the basis of a single variable: controller response time. Controller response time is a function of current system state, system failure rate, electrical and/or magnetic interference, etc., and is therefore a random variable. Control overhead is expressed as a monotonically nondecreasing function of the response time and the system suffers catastrophic failure, or dynamic failure, if the response time for a control task exceeds the corresponding system hard deadline, if any. A rigorous probabilistic approach is used to estimate the performance measures. The controlled process chosen for study is an aircraft in the final stages of descent, just prior to landing. First, the performance measures for the controller are presented. Secondly, control algorithms for solving the landing problem are discussed and finally the impact of the performance measures on the problem is analyzed.

Applications Technology Satellite ATS-6 experiment checkout and continuing spacecraft evaluation report

NASA Technical Reports Server (NTRS)

Moore, W.; Prensky, W. (Editor)

1974-01-01

The activities of the ATS-6 spacecraft are reviewed. The following subsystems and experiments are summarized: (1) radio beacon experiments; (2) spacecraft attitude precision pointing and slewing adaptive control experiment; (3) satellite instruction television experiment; (4) thermal control subsystem; (5) spacecraft propulsion subsystem; (6) telemetry and control subsystem; (7) millimeter wave experiment; and (8) communications subsystem. The results of performance evaluation of its subsystems and experiments are presented.

40 CFR 63.8005 - What requirements apply to my process vessels?

Code of Federal Regulations, 2010 CFR

2010-07-01

... condensers, as defined in § 63.1251, are not considered to be control devices for process vessels. (d... 1 to this subpart, you must conduct the performance test or design evaluation under conditions as specified in § 63.7(e)(1), except that the performance test or design evaluation must be conducted under...

Effect of motor dynamics on nonlinear feedback robot arm control

NASA Technical Reports Server (NTRS)

Tarn, Tzyh-Jong; Li, Zuofeng; Bejczy, Antal K.; Yun, Xiaoping

1991-01-01

A nonlinear feedback robot controller that incorporates the robot manipulator dynamics and the robot joint motor dynamics is proposed. The manipulator dynamics and the motor dynamics are coupled to obtain a third-order-dynamic model, and differential geometric control theory is applied to produce a linearized and decoupled robot controller. The derived robot controller operates in the robot task space, thus eliminating the need for decomposition of motion commands into robot joint space commands. Computer simulations are performed to verify the feasibility of the proposed robot controller. The controller is further experimentally evaluated on the PUMA 560 robot arm. The experiments show that the proposed controller produces good trajectory tracking performances and is robust in the presence of model inaccuracies. Compared with a nonlinear feedback robot controller based on the manipulator dynamics only, the proposed robot controller yields conspicuously improved performance.

Effect of magnetic therapy on selected physical performances.

PubMed

Schall, David M; Ishee, Jimmy H; Titlow, Larry W

2003-05-01

The purpose of this study was to investigate the effects of magnetic therapy in the form of shoe insoles on vertical jump, bench squat, 40-yd dash, and a soccer-specific fitness test performance. Subjects were 14 collegiate male soccer players who were pretested, retested 3 weeks later, and then placed into a double-blind control or treatment group using a matching procedure. The control group received magnetic shoe insoles with a rating of 125 gauss, and the treatment group received insoles with a rating of 600 gauss. Subjects wore the insoles during practice and games for 7 weeks and were then retested. Results indicated significant differences among test scores during the 3 time periods but not between the treatment and control groups. There was a decline in 40-yd dash performance from the initial evaluation (5.10 seconds) to the final evaluation (5.08 seconds). There were no other significant differences. Within the limitations of the study, magnetic therapy did not improve physical performance.

Evaluation of Alternative Field Buses for Lighting ControlApplications

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

Koch, Ed; Rubinstein, Francis

2005-03-21

The Subcontract Statement of Work consists of two major tasks. This report is the Final Report in fulfillment of the contract deliverable for Task 1. The purpose of Task 1 was to evaluate existing and emerging protocols and standards for interfacing sensors and controllers for communicating with integrated lighting control systems in commercial buildings. The detailed task description follows: Task 1. Evaluate alternative sensor/field buses. The objective of this task is to evaluate existing and emerging standards for interfacing sensors and controllers for communicating with integrated lighting control systems in commercial buildings. The protocols to be evaluated will include atmore » least: (1) 1-Wire Net, (2) DALI, (3) MODBUS (or appropriate substitute such as EIB) and (4) ZigBee. The evaluation will include a comparative matrix for comparing the technical performance features of the different alternative systems. The performance features to be considered include: (1) directionality and network speed, (2) error control, (3) latency times, (4) allowable cable voltage drop, (5) topology, and (6) polarization. Specifically, Subcontractor will: (1) Analyze the proposed network architecture and identify potential problems that may require further research and specification. (2) Help identify and specify additional software and hardware components that may be required for the communications network to operate properly. (3) Identify areas of the architecture that can benefit from existing standards and technology and enumerate those standards and technologies. (4) Identify existing companies that may have relevant technology that can be applied to this research. (5) Help determine if new standards or technologies need to be developed.« less

\\t Capital Planning and Investment Control (CPIC) for the Management of Information Technology Investments

EPA Pesticide Factsheets

Capital Planning and Investment Control (CPIC) is the Information Technology (IT) governance and management methodology in use at EPA for selecting, controlling and evaluating the performance of EPA IT investments throughout the full lifecycle.

Design and Evaluation of a Proxy-Based Monitoring System for OpenFlow Networks.

PubMed

Taniguchi, Yoshiaki; Tsutsumi, Hiroaki; Iguchi, Nobukazu; Watanabe, Kenzi

2016-01-01

Software-Defined Networking (SDN) has attracted attention along with the popularization of cloud environment and server virtualization. In SDN, the control plane and the data plane are decoupled so that the logical topology and routing control can be configured dynamically depending on network conditions. To obtain network conditions precisely, a network monitoring mechanism is necessary. In this paper, we focus on OpenFlow which is a core technology to realize SDN. We propose, design, implement, and evaluate a network monitoring system for OpenFlow networks. Our proposed system acts as a proxy between an OpenFlow controller and OpenFlow switches. Through experimental evaluations, we confirm that our proposed system can capture packets and monitor traffic information depending on administrator's configuration. In addition, we show that our proposed system does not influence significant performance degradation to overall network performance.

Design and Evaluation of a Proxy-Based Monitoring System for OpenFlow Networks

PubMed Central

Taniguchi, Yoshiaki; Tsutsumi, Hiroaki; Iguchi, Nobukazu; Watanabe, Kenzi

2016-01-01

Software-Defined Networking (SDN) has attracted attention along with the popularization of cloud environment and server virtualization. In SDN, the control plane and the data plane are decoupled so that the logical topology and routing control can be configured dynamically depending on network conditions. To obtain network conditions precisely, a network monitoring mechanism is necessary. In this paper, we focus on OpenFlow which is a core technology to realize SDN. We propose, design, implement, and evaluate a network monitoring system for OpenFlow networks. Our proposed system acts as a proxy between an OpenFlow controller and OpenFlow switches. Through experimental evaluations, we confirm that our proposed system can capture packets and monitor traffic information depending on administrator's configuration. In addition, we show that our proposed system does not influence significant performance degradation to overall network performance. PMID:27006977

Reduced-cost Chlamydia trachomatis-specific multiplex real-time PCR diagnostic assay evaluated for ocular swabs and use by trachoma research programmes.

PubMed

Butcher, Robert; Houghton, Jo; Derrick, Tamsyn; Ramadhani, Athumani; Herrera, Beatriz; Last, Anna R; Massae, Patrick A; Burton, Matthew J; Holland, Martin J; Roberts, Chrissy H

2017-08-01

Trachoma, caused by the intracellular bacterium Chlamydia trachomatis (Ct), is the leading infectious cause of preventable blindness. Many commercial platforms are available that provide highly sensitive and specific detection of Ct DNA. However, the majority of these commercial platforms are inaccessible for population-level surveys in resource-limited settings typical to trachoma control programmes. We developed two low-cost quantitative PCR (qPCR) tests for Ct using readily available reagents on standard real-time thermocyclers. Each multiplex qPCR test targets one genomic and one plasmid Ct target in addition to an endogenous positive control for Homo sapiens DNA. The quantitative performance of the qPCR assays in clinical samples was determined by comparison to a previously evaluated droplet digital PCR (ddPCR) test. The diagnostic performance of the qPCR assays were evaluated against a commercial assay (artus C. trachomatis Plus RG PCR, Qiagen) using molecular diagnostics quality control standards and clinical samples. We examined the yield of Ct DNA prepared from five different DNA extraction kits and a cold chain-free dry-sample preservation method using swabs spiked with fixed concentrations of human and Ct DNA. The qPCR assay was highly reproducible (Ct plasmid and genomic targets mean total coefficients of variance 41.5% and 48.3%, respectively). The assay detected 8/8 core specimens upon testing of a quality control panel and performed well in comparison to commercially marketed comparator test (sensitivity and specificity>90%). Optimal extraction and sample preservation methods for research applications were identified. We describe a pipeline from collection to diagnosis providing the most efficient sample preservation and extraction with significant per test cost savings over a commercial qPCR diagnostic assay. The assay and its evaluation should allow control programs wishing to conduct independent research within the context of trachoma control, access to an affordable test with defined performance characteristics. Copyright © 2017. Published by Elsevier B.V.

An evaluative model of system performance in manned teleoperational systems

NASA Technical Reports Server (NTRS)

Haines, Richard F.

1989-01-01

Manned teleoperational systems are used in aerospace operations in which humans must interact with machines remotely. Manual guidance of remotely piloted vehicles, controling a wind tunnel, carrying out a scientific procedure remotely are examples of teleoperations. A four input parameter throughput (Tp) model is presented which can be used to evaluate complex, manned, teleoperations-based systems and make critical comparisons among candidate control systems. The first two parameters of this model deal with nominal (A) and off-nominal (B) predicted events while the last two focus on measured events of two types, human performance (C) and system performance (D). Digital simulations showed that the expression A(1-B)/C+D) produced the greatest homogeneity of variance and distribution symmetry. Results from a recently completed manned life science telescience experiment will be used to further validate the model. Complex, interacting teleoperational systems may be systematically evaluated using this expression much like a computer benchmark is used.

Integrated flight/propulsion control system design based on a decentralized, hierarchical approach

NASA Technical Reports Server (NTRS)

Mattern, Duane; Garg, Sanjay; Bullard, Randy

1989-01-01

A sample integrated flight/propulsion control system design is presented for the piloted longitudinal landing task with a modern, statistically unstable fighter aircraft. The design procedure is summarized. The vehicle model used in the sample study is described, and the procedure for partitioning the integrated system is presented along with a description of the subsystems. The high-level airframe performance specifications and control design are presented and the control performance is evaluated. The generation of the low-level (engine) subsystem specifications from the airframe requirements are discussed, and the engine performance specifications are presented along with the subsystem control design. A compensator to accommodate the influence of airframe outputs on the engine subsystem is also considered. Finally, the entire closed loop system performance and stability characteristics are examined.

Integrated flight/propulsion control system design based on a decentralized, hierarchical approach

NASA Technical Reports Server (NTRS)

Mattern, Duane; Garg, Sanjay; Bullard, Randy

1989-01-01

A sample integrated flight/propulsion control system design is presented for the piloted longitiudinal landing task with a modern, statistically unstable fighter aircraft. The design procedure is summarized, the vehicle model used in the sample study is described, and the procedure for partitioning the integrated system is presented along with a description of the subsystems. The high-level airframe performance specifications and control design are presented and the control performance is evaluated. The generation of the low-level (engine) subsystem specifications from the airframe requirements are discussed, and the engine performance specifications are presented along with the subsystem control design. A compensator to accommodate the influence of airframe outputs on the engine subsystem is also considered. Finally, the entire closed loop system performance and stability characteristics are examined.

Effect of insulin therapy and dietary adjustments on safety and performance during simulated soccer tests in people with type 1 diabetes: study protocol for a randomized controlled trial.

PubMed

Calvo-Marín, Javier; Torrealba-Acosta, Gabriel; Campbell, Matthew; Gaboury, Jesse; Ali, Ajmol; Chen-Ku, Chih Hao

2017-07-20

Despite the reduction in glycemic derangement in patients with type 1 diabetes mellitus (T1D) through dietary and therapeutic adjustments implemented before, during and after continuous exercise, evidence for its effectiveness with intermittent forms of exercise, such as soccer, is still lacking. We designed a study protocol for a randomized, crossover, double-blinded, controlled trial, for the evaluation of the effect that a strategy of dietary and therapeutic modifications may have on safety and performance of persons with T1D in soccer training sessions and cognitive testing. Inclusion criteria comprise: age older than 18 years, more than 2 years since T1D diagnosis, low C-peptide level, a stable insulin regimen, HbA1c less than 9.0% and regular participation in soccer activities. Our primary outcome evaluates safety regarding hypoglycemia events in patients using dietary and therapeutic adjustments, compared with the performance under the implementation of current American Diabetes Association (ADA) usual recommendations for nutritional and pharmacological adjustments for exercise. Additionally, we will evaluate as secondary outcomes: soccer performance, indexed by performance in well-established soccer skill tests, cognitive functions (indexed by Stroop, digital vigilance test (DVT), Corsi block-tapping task (CBP), and rapid visual information processing (RVIP) tests), and glycemic control measured with a continuous glucose monitor (CGM). Dietary and insulin adjustments standardized under a 4-step method strategy have never been tested in a clinical trial setting with intermittent forms of exercise, such as soccer. We hypothesize that through this strategy we will observe better performance by persons with T1D in soccer and cognitive evaluations, and more stable control of glycemic parameters before, during and after exercise execution, indexed by CGM measurements. ISRCTN, ISRCTN17447843. Registered on 5 January 2017.

Flight testing the Digital Electronic Engine Control (DEEC) A unique management experience

NASA Technical Reports Server (NTRS)

Putnam, T. W.; Burcham, F. W., Jr.; Kock, B. M.

1983-01-01

The concept for the DEEC had its origin in the early 1970s. At that time it was recognized that the F100 engine performance, operability, reliability, and cost could be substantially improved by replacing the original mechanical/supervisory electronic control system with a full-authority digital control system. By 1978, the engine manufacturer had designed and initiated the procurement of flight-qualified control system hardware. As a precursor to an integrated controls program, a flight evaluation of the DEEC system on the F-15 aircraft was proposed. Questions regarding the management of the DEEC flight evaluation program are discussed along with the program elements, the technical results of the F-15 evaluation, and the impact of the flight evaluation on after-burning turbofan controls technology and its use in and application to military aircraft. The lessons learned through the conduct of the program are discussed.

Job control and coworker support improve employee job performance.

PubMed

Nagami, Makiko; Tsutsumi, Akizumi; Tsuchiya, Masao; Morimoto, Kanehisa

2010-01-01

We examined the prospective association of psychosocial job characteristics with employee job performance among 777 full-time employees at a manufacturing company in Japan, using data from a one-year follow-up survey. Psychosocial job characteristics were measured by the Job Content Questionnaire in 2008; job performance was evaluated using the item from the World Mental Health Survey Instrument in 2008 and 2009. The association between psychosocial job characteristics and job performance was tested using multiple regression analysis, controlling for demographic variables, work status, average working hours per day, job type and job performance in 2008. Job control and coworker support in 2008 were positively related to job performance in 2009. Stratified analyses revealed that job control for staff and coworker support for managers were positively related to job performance in 2009. These associations were prominent among men; however, supervisor support in 2008 was negatively related to job performance in 2009 among men. Job demand was not significantly related to job performance. Our findings suggest that it is worthwhile to enhance employees' job control and provide a mutually supportive environment to ensure positive employee job performance.

Design study for LANDSAT D attitude control system

NASA Technical Reports Server (NTRS)

Iwens, R. P.; Bernier, G. E.; Hofstadter, R. F.

1976-01-01

A design and performance evaluation is presented for the LANDSAT D attitude control system (ACS). Control and configuration of the gimballed Ku-band antenna system for communication with the tracking and data relay satellite (TDRS). Control of the solar array drive considered part of the ACS is also addressed.

Effect of a brief training program based on cognitive behavioral therapy in improving work performance: A randomized controlled trial.

PubMed

Kimura, Risa; Mori, Makiko; Tajima, Miyuki; Somemura, Hironori; Sasaki, Norio; Yamamoto, Megumi; Nakamura, Saki; Okanoya, June; Ito, Yukio; Otsubo, Tempei; Tanaka, Katsutoshi

2015-01-01

Efforts to improve performance in the workplace with respect to positive mental health have increased, and cognitive behavioral therapy (CBT) has recently attracted attention as an intervention measure to this end. Here, we conducted a randomized controlled trial to evaluate the effectiveness of a brief training program on CBT for improving work performance of employees. The participants were employees of an electric company in Japan. The intervention consisted of 1 group session of CBT (120 min) and web-based CBT homework for 1 month. We evaluated employees in both the intervention and control groups at baseline and follow-up after three months. The main outcome was work performance, which was evaluated by a subjective score from 1 to 10. The secondary outcome was self-evaluation of cognitive flexibility. Analyses were conducted based on ITT. In the intervention group, 84 participants attended the group session, with 79 subsequently completing at least 1 instance of online homework. ITT analysis showed that the subjective performance of the intervention group was significantly improved compared with that of the control group (1.47 vs. 0.69, mean difference 0.78 [95% confidence interval {CI}, 0.05 to 1.51], Cohen's d=0.31). The ability to recognize dysfunctional thinking patterns and change them to positive ones significantly improved in the intervention group compared to the control group (0.71 vs. 0.26, mean difference 0.45 [95% CI 0.06 to 0.83], d=0.33). However, after adjustment for baseline scores, no significant difference was observed. The ability to view a situation from multiple perspectives and expand one's repertoire of thought patterns in the intervention group also significantly improved (0.83 vs. 0.35, mean difference 0.48 [95% CI 0.35 to 0.95], d=0.29), but here again, significance was lost after adjusting for baseline scores. Our results suggest that a brief training program that combines a group CBT session with web-based CBT homework improved subjective work performance. In addition, this program might help improve employees' cognitive flexibility.

Towards a balanced performance measurement system in a public health care organization.

PubMed

Yuen, Peter P; Ng, Artie W

2012-01-01

This article attempts to devise an integrated performance measurement framework to assess the Hong Kong Hospital Authority (HA) management system by harnessing previous performance measurement systems. An integrated evaluative framework based on the balanced score card (BSC) was developed and applied using the case study method and longitudinal data to evaluate the HA's performance management system. The authors unveil evolving HA performance indicators (P1). Despite the HA staffs explicit quality emphasis, cost control remains the primary focus in their performance measurements. RESEARCH LHNITATIONS/IMPLICATIONS: Data used in this study are from secondary sources, disclosed mostly by HA staff. This study shows public sector staff often attach too much importance to cost control and easily measurable activities at the expense of quality and other less easily measurable attributes'. A balanced performance measurement system, linked to health targets, with a complementary budgeting process that supports pertinent resource allocation is yet to be implemented in Hong Kong's public hospitals.

Performance Evaluation of a Data Validation System

NASA Technical Reports Server (NTRS)

Wong, Edmond (Technical Monitor); Sowers, T. Shane; Santi, L. Michael; Bickford, Randall L.

2005-01-01

Online data validation is a performance-enhancing component of modern control and health management systems. It is essential that performance of the data validation system be verified prior to its use in a control and health management system. A new Data Qualification and Validation (DQV) Test-bed application was developed to provide a systematic test environment for this performance verification. The DQV Test-bed was used to evaluate a model-based data validation package known as the Data Quality Validation Studio (DQVS). DQVS was employed as the primary data validation component of a rocket engine health management (EHM) system developed under NASA's NGLT (Next Generation Launch Technology) program. In this paper, the DQVS and DQV Test-bed software applications are described, and the DQV Test-bed verification procedure for this EHM system application is presented. Test-bed results are summarized and implications for EHM system performance improvements are discussed.

Conjugating binary systems for spacecraft thermal control

NASA Technical Reports Server (NTRS)

Grodzka, Philomena G.; Dean, William G.; Sisk, Lori A.; Karu, Zain S.

1989-01-01

The materials search was directed to liquid pairs which can form hydrogen bonds of just the right strength, i.e., strong enough to give a high heat of mixing, but weak enough to enable phase change to occur. The cursory studies performed in the area of additive effects indicate that Conjugating Binary (CB) performance can probably be fine-tuned by this means. The Fluid Loop Test Systems (FLTS) tests of candidate CBs indicate that the systems Triethylamine (TEA)/water and propionaldehyde/water show close to the ideal, reversible behavior, at least initially. The Quick Screening Tests QSTs and FLTS tests, however, both suffer from rather severe static due either to inadequate stirring or temperature control. Thus it is not possible to adequately evaluate less than ideal CB performers. Less than ideal performers, it should be noted, may have features that make them better practical CBs than ideal performers. Improvement of the evaluation instrumentation is thus indicated.

Positioning and tracking control system analysis for mobile free space optical network

NASA Astrophysics Data System (ADS)

Li, Yushan; Refai, Hazem; Sluss, , James J., Jr.; Verma, Pramode; LoPresti, Peter

2005-08-01

Free Space Optical (FSO) communication has evolved to be applied to the mobile network, because it can provide up to 2.5Gbps or higher data rate wireless communication. One of the key challenges with FSO systems is to maintain the Line of Sight (LOS) between transmitter and receiver. In this paper, the feasibility and performance of applying the FSO technology to the mobile network is explored, and the design plan of the attitude positioning and tracking control system of the FSO transceiver is investigated. First, the system architecture is introduced, the requirements for the control system are analyzed, the involved reference frames and frame transformation are presented. Second, the control system bandwidth is used to evaluate the system performance in controlling a positioning system consisting of a gimbal and a steering mirror, some definitions to describe the positioning accuracy and tracking capacity are given. The attitude control of a FSO transceiver is split into 2 similar channels: pitch and yaw. Using an equivalent linear control system model, the simulations are carried out, with and without the presence of uncertainties that includes GPS data errors and sensor measurement errors. Finally, based on the simulation results in the pitch channel, the quantitative evaluation on the performance of the control system is given, including positioning accuracy, tracking capability and uncertainty tolerance.

Methylphenidate Reduces State Anxiety During a Continuous Performance Test That Distinguishes Adult ADHD Patients From Controls.

PubMed

Bloch, Yuval; Aviram, Shai; Segev, Aviv; Nitzan, Uri; Levkovitz, Yechiel; Braw, Yoram; Mimouni Bloch, Aviva

2017-01-01

We hypothesized that patients with ADHD were typified by distress more than by functional difficulties. Thus, a decline in state anxiety while performing a cognitive task when taking methylphenidate would discriminate between ADHD patients and controls. State anxiety and cognitive performance on a continuous performance test were assessed in ADHD patients and controls with and without taking methylphenidate. State anxiety and cognitive performance improved from baseline in 36 ADHD adults after taking methylphenidate. In 25 controls, cognitive performance improved, but state anxiety did not abate after a recess. In two additional studies, 5 controls were evaluated at baseline and after receiving methylphenidate, and showed improvement in cognitive assessment but not in state anxiety. Five ADHD adults were assessed at baseline and after a recess, and showed no improvement. Our results support the hypothesis that adult ADHD patients are characterized by distress and the relief of this distress under effective therapy as expressed by a decline in state anxiety while they perform a cognitive task.

Propulsion system-flight control integration and optimization: Flight evaluation and technology transition

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Gilyard, Glenn B.; Myers, Lawrence P.

1990-01-01

Integration of propulsion and flight control systems and their optimization offers significant performance improvements. Research programs were conducted which have developed new propulsion and flight control integration concepts, implemented designs on high-performance airplanes, demonstrated these designs in flight, and measured the performance improvements. These programs, first on the YF-12 airplane, and later on the F-15, demonstrated increased thrust, reduced fuel consumption, increased engine life, and improved airplane performance; with improvements in the 5 to 10 percent range achieved with integration and with no changes to hardware. The design, software and hardware developments, and testing requirements were shown to be practical.

Performance evaluation on air pollution reducing facilities and mechanism research on the third-party governance on environmental pollution

NASA Astrophysics Data System (ADS)

Bingsheng, Xu; Ling, Lin; Jin, Huang; Geng, Wang; Jianhua, Chen; Shuo, Yang; Huiting, Guo

2017-11-01

The paper focuses on developing the operational efficiency of air pollution reducing facilities and the treatment effect of the third-party governance on environmental pollution. Comprehensive analysis method and influence factor analysis are employed to build an evaluation index system by means of discussing major pollution control factors derived from the performance of pollution control equipment operation, environmental protection, technological economy, recourse consumption and manufacturing management. Based on the pattern of environmental pollution control offered by the third-party company, the static games model is further established between the government and the pollution emission firm by considering the whole process of the pollution abatement including investment, construction and operation of the treatment project, which focuses on establishing the policy condition and consequence by discussing the cost and benefit in a short and a long time, respectively. The research results can improve the market access requests of the pollution control equipment and normalize the environmental protection service offered by the third-party company. Moreover, the establishment of the evaluation index system for pollution control equipment and the evaluation mechanism for the third-party governance on environmental pollution has guiding significance on leading environmental protection industry and promoting market-oriented development

Progress Report for the Robotic Intelligence Evaluation. Program Year 1: Developing Test Methodology for Anti-Rollover Systems

DTIC Science & Technology

2006-06-01

Scientific Research. 5PAM-Crash is a trademark of the ESI Group . 6MATLAB and SIMULINK are registered trademarks of the MathWorks. 14 maneuvers...Laboratory (ARL) to develop methodologies to evaluate robotic behavior algorithms that control the actions of individual robots or groups of robots...methodologies to evaluate robotic behavior algorithms that control the actions of individual robots or groups of robots acting as a team to perform a

A Technique for Evaluating Vendor Bids for Stock Replenishment of a Consumable Item.

DTIC Science & Technology

1985-06-01

RD-A159 957 A TECHNIQUE FOR EVALUATING VENDOR BIDS FOR STOCK 1/1 REPLENISHMENT OF A CONSUMABLE I TEM(U) NAVAL POSTGRADUATE SCHOOL MONTEREY CA J...REPORT II PER106 COVERED *A Technique for Evaluating Vendor Bids Juner’ 1985 i for Stock Replenishment of a Consumable tern 6. PERFORMING ORG. REPORT...Control Center (SPCC) Uniform Inventory Control Program (UICP) wholesale replenishment model for 1H cognizance symbol ( consumable ) material is an order

Test and evaluation of the HIDEC engine uptrim algorithm

NASA Technical Reports Server (NTRS)

Ray, R. J.; Myers, L. P.

1986-01-01

The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrated engine-airframe control systems. Performance improvements will result from an adaptive engine stall margin mode, a highly integrated mode that uses the airplane flight conditions and the resulting inlet distortion to continuously compute engine stall margin. When there is excessive stall margin, the engine is uptrimmed for more thrust by increasing engine pressure ratio (EPR). The EPR uptrim logic has been evaluated and implemented into computer simulations. Thrust improvements over 10 percent are predicted for subsonic flight conditions. The EPR uptrim was successfully demonstrated during engine ground tests. Test results verify model predictions at the conditions tested.

Assessment of Anatomical Knowledge and Core Trauma Competency Vascular Skills.

PubMed

Granite, Guinevere; Pugh, Kristy; Chen, Hegang; Longinaker, Nyaradzo; Garofalo, Evan; Shackelford, Stacy; Shalin, Valerie; Puche, Adam; Pasley, Jason; Sarani, Babak; Henry, Sharon; Bowyer, Mark; Mackenzie, Colin

2018-03-01

Surgical residents express confidence in performing specific vascular exposures before training, but such self-reported confidence did not correlate with co-located evaluator ratings. This study reports residents' self-confidence evaluated before and after Advanced Surgical Skills for Exposure in Trauma (ASSET) cadaver-based training, and 12-18 mo later. We hypothesize that residents will better judge their own skill after ASSET than before when compared with evaluator ratings. Forty PGY2-7 surgical residents performed four procedures: axillary artery (AA), brachial artery (BA), femoral artery exposure and control (FA), and lower extremity fasciotomy (FAS) at the three evaluations. Using 5-point Likert scales, surgeons self-assessed their confidence in anatomical understanding and procedure performance after each procedure and evaluators rated each surgeon accordingly. For all the three evaluations, residents consistently rated their anatomical understanding (p < 0.04) and surgical performance (p < 0.03) higher than evaluators for both FA and FAS. Residents rated their anatomical understanding and surgical performance higher (p < 0.005) than evaluators for BA after training and up to 18 mo later. Only for third AA evaluation were there no rating differences. Residents overrate their anatomical understanding and performance abilities for BA, FA, and FAS even after performing the procedures and being debriefed three times in 18 mo.

Efficacy of a barrier gel for reducing the development of plaque, calculus, and gingivitis in cats.

PubMed

Bellows, Jan; Carithers, Douglas S; Gross, Sheila J

2012-01-01

This study was performed to assess the field efficacy of a professional and home-care barrier gel against the development of plaque, calculus, gingival bleeding, and gingivitis in client-owned cats over a 56-day period compared with negative controls. In a randomized, negative-controlled, outcome evaluator-blinded, client-owned animal clinical field study, 31 cats were evaluated to assess if the barrier gel dental product was effective in cats. Following an enrollment-qualification assessment and enrollment of each cat, all cats received a professional dental cleaning, including polishing and irrigation. Following cleaning, a post-cleaning assessment was performed by the evaluator. Then, using a pre-developed randomization schedule, cats were assigned to the treated or control group. The professional version of the barrier gel was applied to the treated group on day 0. The negative-control group patients did not receive any applications of the barrier gel following dental cleaning. Treated-group cats were brought back to the clinic for subsequent applications of the home-care version of the barrier gel, applied by a non-blinded trained assistant. The home-care version product applications began on day 14 and then were applied weekly (days, 21, 28, 35, 42, 49 and 56) through day 56. All cats enrolled in the study underwent full oral examinations and assessments by the blinded evaluator on or about their respective days 28 and 56. At these evaluations, the evaluator performed standardized assessments for plaque, calculus, gingivitis, and gingival bleeding. Numeric scores were assigned for each assessment using predetermined target teeth to ensure consistency. Using these assessment scores, statistical analyses were performed to determine the efficacies against plaque and calculus deposition; additionally, measurements of gingivitis and gingival bleeding were assessed. Change in plaque score from baseline, for all teeth assessed (all 4 canine teeth, and all 4 [corrected] premolar teeth), was significantly (P < 0.05) lower for treated cats than for control cats for both left side average and right side average on day 56. No statistical differences were seen for calculus, gingivitis, or gingival bleeding in this study. In cats with a history of developing plaque, application of the barrier gel dental product following dental cleaning reduced plaque deposition (P < 0.05) compared with control cats.

Performance of the active sidewall boundary-layer removal system for the Langley 0.3-meter Transonic Cryogenic Tunnel

NASA Technical Reports Server (NTRS)

Balakrishna, S.; Kilgore, W. Allen; Murthy, A. V.

1989-01-01

A performance evaluation of an active sidewall boundary-layer removal system for the Langley 0.3-m Transonic Cryogenic Tunnel (TCT) was evaluated in 1988. This system uses a compressor and two throttling digital valves to control the boundary-layer mass flow removal from the tunnel. The compressor operates near the maximum pressure ratio for all conditions. The system uses a surge prevention and flow recirculation scheme. A microprocessor based controller is used to provide the necessary mass flow and compressor pressure ratio control. Initial tests on the system indicated problems in realizing smooth mass flow control while running the compressor at high speed and high pressure ratios. An alternate method has been conceived to realize boundary-layer mass flow control which avoids the recirculation of the compressor mass flow and operation near the compressor surge point. This scheme is based on varying the speed of the compressor for a sufficient pressure ratio to provide needed mass flow removal. The system has a mass flow removal capability of about 10 percent of test section flow at M = 0.3 and 4 percent at M = 0.8. The system performance has been evaluated in the form of the compressor map, and compressor tunnel interface characteristics covering most of the 0.3-m TCT operational envelope.

Computer graphics for quality control in the INAA of geological samples

USGS Publications Warehouse

Grossman, J.N.; Baedecker, P.A.

1987-01-01

A data reduction system for the routine instrumental activation analysis of samples is described, with particular emphasis on interactive graphics capabilities for evaluating analytical quality. Graphics procedures have been developed to interactively control the analysis of selected photopeaks during spectral analysis, and to evaluate detector performance during a given counting cycle. Graphics algorithms are also used to compare the data on reference samples with accepted values, to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time. ?? 1987 Akade??miai Kiado??.

Performance evaluation of mobile downflow booths for reducing airborne particles in the workplace.

PubMed

Lo, Li-Ming; Hocker, Braden; Steltz, Austin E; Kremer, John; Feng, H Amy

2017-11-01

Compared to other common control measures, the downflow booth is a costly engineering control used to contain airborne dust or particles. The downflow booth provides unidirectional filtered airflow from the ceiling, entraining released particles away from the workers' breathing zone, and delivers contained airflow to a lower level exhaust for removing particulates by filtering media. In this study, we designed and built a mobile downflow booth that is capable of quick assembly and easy size change to provide greater flexibility and particle control for various manufacturing processes or tasks. An experimental study was conducted to thoroughly evaluate the control performance of downflow booths used for removing airborne particles generated by the transfer of powdered lactose between two containers. Statistical analysis compared particle reduction ratios obtained from various test conditions including booth size (short, regular, or extended), supply air velocity (0.41 and 0.51 m/s or 80 and 100 feet per minute, fpm), powder transfer location (near or far from the booth exhaust), and inclusion or exclusion of curtains at the booth entrance. Our study results show that only short-depth downflow booths failed to protect the worker performing powder transfer far from the booth exhausts. Statistical analysis shows that better control performance can be obtained with supply air velocity of 0.51 m/s (100 fpm) than with 0.41 m/s (80 fpm) and that use of curtains for downflow booths did not improve their control performance.

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices...) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550, you...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2011 CFR

2011-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices...) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550, you...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2014 CFR

2014-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices... (c) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices... (c) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550...

40 CFR 63.2460 - What requirements must I meet for batch process vents?

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (ii) When you conduct a performance test or design evaluation for a non-flare control device used to... paragraphs (c)(9)(ii)(A) through (D) of this section. The design evaluation option for small control devices... (c) of this section. (b) Group status. If a process has batch process vents, as defined in § 63.2550...

Rigorous Program Evaluations on a Budget: How Low-Cost Randomized Controlled Trials Are Possible in Many Areas of Social Policy

ERIC Educational Resources Information Center

Coalition for Evidence-Based Policy, 2012

2012-01-01

The increasing ability of social policy researchers to conduct randomized controlled trials (RCTs) at low cost could revolutionize the field of performance-based government. RCTs are widely judged to be the most credible method of evaluating whether a social program is effective, overcoming the demonstrated inability of other, more common methods…

An Assessment of Statistical Process Control-Based Approaches for Charting Student Evaluation Scores

ERIC Educational Resources Information Center

Ding, Xin; Wardell, Don; Verma, Rohit

2006-01-01

We compare three control charts for monitoring data from student evaluations of teaching (SET) with the goal of improving student satisfaction with teaching performance. The two charts that we propose are a modified "p" chart and a z-score chart. We show that these charts overcome some of the shortcomings of the more traditional charts…

Evaluating School-Based Tobacco Control Programs and Policies: An Opportunity Gained and Many Opportunities Lost

ERIC Educational Resources Information Center

Leatherdale, Scott T.

2009-01-01

In the domain of school-based tobacco control, there is a large gap between the research being performed and the type of research needed to inform school-based prevention activities. The tobacco module of the school health action planning and evaluation system is a data collection and feedback system designed to support school-based tobacco…

Forward-viewing endoscopic ultrasound-guided NOTES interventions: A study on peritoneoscopic potential

PubMed Central

Jeong, Seung Uk; Aizan, Hassanuddin; Song, Tae Jun; Seo, Dong Wan; Kim, Su-Hui; Park, Do Hyun; Lee, Sang Soo; Lee, Sung Koo; Kim, Myung-Hwan

2013-01-01

AIM: To evaluate the feasibility of diagnostic and therapeutic transgastric (TG) peritoneoscopic interventions with a forward-viewing endoscopic ultrasound (FV-EUS). METHODS: This prospective endoscopic experimental study used an animal model. Combined TG peritoneoscopic interventions and EUS examination of the intra-abdominal organs were performed using an FV-EUS on 10 animal models (1 porcine and 9 canine). The procedures carried out include EUS evaluation and endoscopic biopsy of intraperitoneal organs, EUS-guided fine needle aspiration (EUS-FNA), EUS-guided radiofrequency ablation (EUS-RFA), and argon plasma coagulation (APC) for hemostatic control. The animals were kept alive for 7 d, and then necropsy was performed to evaluate results and complications. RESULTS: In all 10 animals, TG peritoneoscopy, followed by endoscopic biopsy for the liver, spleen, abdominal wall, and omentum, was performed successfully. APC helped control minor bleeding. Visualization of intra-abdominal solid organs with real-time EUS was accomplished with ease. Intraperitoneal EUS-FNA was successfully performed on the liver, spleen, and kidney. Similarly, a successful outcome was achieved with EUS-RFA of the hepatic parenchyma. No adverse events were recorded during the study. CONCLUSION: Peritoneoscopic natural orifice transluminal endoscopic surgery (NOTES) interventions through FV-EUS were feasible in providing evaluation and performing endoscopic procedures. It promises potential as a platform for future EUS-based NOTES. PMID:24222961

Storm Water Control Management & Monitoring

DOT National Transportation Integrated Search

2017-11-30

Temple and Villanova universities collected monitoring and assessment data along the I-95 corridor to evaluate the performance of current stormwater control design and maintenance practices. An extensive inventory was developed that ranks plants in t...

Performance evaluation of traffic sensing and control devices.

DOT National Transportation Integrated Search

2011-01-01

High quality vehicle detection is essential to properly operate actuated phases at traffic signals and to facilitate effective : management of technician and engineering resources. INDOT operates over 2600 traffic signal controllers, approximately 20...

Airborne Data Link Operational Evaluation Test Plan

DOT National Transportation Integrated Search

1993-08-01

This plan describes an end-to-end study of operational concepts and procedures associated with the introduction of electronic data communications between flight crews and air traffic controllers. Full performance controllers from : terminal facilitie...

Metacognition in Upper-Division Biology Students: Awareness Does Not Always Lead to Control

PubMed Central

Dye, Kathryn Morris; Stanton, Julie Dangremond

2017-01-01

Students with awareness and control of their own thinking can learn more and perform better than students who are not metacognitive. Metacognitive regulation is how you control your thinking in order to learn. It includes the skill of evaluation, which is the ability to appraise your approaches to learning and then modify future plans based on those appraisals. We asked when, why, and how upper-division biology students evaluated their approaches to learning. We used self-evaluation assignments to identify students with potentially high metacognition and conducted semistructured interviews to collect rich qualitative data from them. Through content analysis, we found that students evaluated their approaches to learning when their courses presented novel challenges. Most students evaluated in response to an unsatisfactory grade. While evaluating study strategies, many students considered performance and learning simultaneously. We gained insights on the barriers students face when they try to change their approaches to learning based on their evaluations. A few students continued to use ineffective study strategies even though they were aware of the ineffectiveness of those strategies. A desire to avoid feeling uncomfortable was the primary reason they avoided strategies that they knew were more effective. We examined the behavioral change literature to help interpret these findings. PMID:28495935

Development of an adaptive failure detection and identification system for detecting aircraft control element failures

NASA Technical Reports Server (NTRS)

Bundick, W. Thomas

1990-01-01

A methodology for designing a failure detection and identification (FDI) system to detect and isolate control element failures in aircraft control systems is reviewed. An FDI system design for a modified B-737 aircraft resulting from this methodology is also reviewed, and the results of evaluating this system via simulation are presented. The FDI system performed well in a no-turbulence environment, but it experienced an unacceptable number of false alarms in atmospheric turbulence. An adaptive FDI system, which adjusts thresholds and other system parameters based on the estimated turbulence level, was developed and evaluated. The adaptive system performed well over all turbulence levels simulated, reliably detecting all but the smallest magnitude partially-missing-surface failures.

Structural dynamic interaction with solar tracking control for evolutionary Space Station concepts

NASA Technical Reports Server (NTRS)

Lim, Tae W.; Cooper, Paul A.; Ayers, J. Kirk

1992-01-01

The sun tracking control system design of the Solar Alpha Rotary Joint (SARJ) and the interaction of the control system with the flexible structure of Space Station Freedom (SSF) evolutionary concepts are addressed. The significant components of the space station pertaining to the SARJ control are described and the tracking control system design is presented. Finite element models representing two evolutionary concepts, enhanced operations capability (EOC) and extended operations capability (XOC), are employed to evaluate the influence of low frequency flexible structure on the control system design and performance. The design variables of the control system are synthesized using a constrained optimization technique to meet design requirements, to provide a given level of control system stability margin, and to achieve the most responsive tracking performance. The resulting SARJ control system design and performance of the EOC and XOC configurations are presented and compared to those of the SSF configuration. Performance limitations caused by the low frequency of the dominant flexible mode are discussed.

Towards practical control design using neural computation

NASA Technical Reports Server (NTRS)

Troudet, Terry; Garg, Sanjay; Mattern, Duane; Merrill, Walter

1991-01-01

The objective is to develop neural network based control design techniques which address the issue of performance/control effort tradeoff. Additionally, the control design needs to address the important issue if achieving adequate performance in the presence of actuator nonlinearities such as position and rate limits. These issues are discussed using the example of aircraft flight control. Given a set of pilot input commands, a feedforward net is trained to control the vehicle within the constraints imposed by the actuators. This is achieved by minimizing an objective function which is the sum of the tracking errors, control input rates and control input deflections. A tradeoff between tracking performance and control smoothness is obtained by varying, adaptively, the weights of the objective function. The neurocontroller performance is evaluated in the presence of actuator dynamics using a simulation of the vehicle. Appropriate selection of the different weights in the objective function resulted in the good tracking of the pilot commands and smooth neurocontrol. An extension of the neurocontroller design approach is proposed to enhance its practicality.

Evolving Multi Rover Systems in Dynamic and Noisy Environments

NASA Technical Reports Server (NTRS)

Tumer, Kagan; Agogino, Adrian

2005-01-01

In this chapter, we address how to evolve control strategies for a collective: a set of entities that collectively strives to maximize a global evaluation function that rates the performance of the full system. Addressing such problems by directly applying a global evolutionary algorithm to a population of collectives is unworkable because the search space is prohibitively large. Instead, we focus on evolving control policies for each member of the collective, where each member is trying to maximize the fitness of its own population. The main difficulty with this approach is creating fitness evaluation functions for the members of the collective that induce the collective to achieve high performance with respect to the system level goal. To overcome this difficulty, we derive member evaluation functions that are both aligned with the global evaluation function (ensuring that members trying to achieve high fitness results in a collective with high fitness) and sensitive to the fitness of each member (a member's fitness depends more on its own actions than on actions of other members). In a difficult rover coordination problem in dynamic and noisy environments, we show how to construct evaluation functions that lead to good collective behavior. The control policy evolved using aligned and member-sensitive evaluations outperforms global evaluation methods by up to a factor of four. in addition we show that the collective continues to perform well in the presence of high noise levels and when the environment is highly dynamic. More notably, in the presence of a larger number of rovers or rovers with noisy sensors, the improvements due to the proposed method become significantly more pronounced.

X-48B Flight Test Progress Overview

NASA Technical Reports Server (NTRS)

Risch, Timoth K.; Cosentino, Gary B.; Regan, Christopher D.; Kisska, Michael; Princen, Norman

2009-01-01

The results of a series of 39 flight tests of the X-48B Low Speed Vehicle (LSV) performed at the NASA Dryden Flight Research Center from July 2007 through December 2008 are reported here. The goal of these tests is to evaluate the aerodynamic and controls and dynamics performance of the subscale LSV aircraft, eventually leading to the development of a control system for a full-scale vehicle. The X-48B LSV is an 8.5%-scale aircraft of a potential, full-scale Blended Wing Body (BWB) type aircraft and is flown remotely from a ground control station using a computerized flight control system located onboard the aircraft. The flight tests were the first two phases of a planned three-phase research program aimed at ascertaining the flying characteristics of this type of aircraft. The two test phases reported here are: 1) envelope expansion, during which the basic flying characteristics of the airplane were examined, and 2) parameter identification, stalls, and engine-out testing, during which further information on the aircraft performance was obtained and the airplane was tested to the limits of controlled flight. The third phase, departure limiter assaults, has yet to be performed. Flight tests in two different wing leading edge configurations (slats extended and slats retracted) as well as three weight and three center of gravity positions were conducted during each phase. Data gathered in the test program included measured airplane performance parameters such as speed, acceleration, and control surface deflections along with qualitative flying evaluations obtained from pilot and crew observations. Flight tests performed to-date indicate the aircraft exhibits good handling qualities and performance, consistent with pre-flight simulations.

Progressing quality control in environmental impact assessment beyond legislative compliance: An evaluation of the IEMA EIA Quality Mark certification scheme

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

Bond, Alan, E-mail: alan.bond@uea.ac.uk; Research Unit for Environmental Sciences and Management, North-West University; Fischer, Thomas B, E-mail: fischer@liverpool.ac.uk

The effectiveness of Environmental Impact Assessment (EIA) systems is contingent on a number of control mechanisms: procedural; judicial; evaluative; public and government agency; professional; and development aid agency. If we assume that procedural and judicial controls are guaranteed in developed EIA systems, then progressing effectiveness towards an acceptable level depends on improving the performance of other control mechanisms over time. These other control mechanisms are either absent, or are typically centrally controlled, requiring public finances; this we argue is an unpopular model in times of greater Government austerity. Here we evaluate a market-based mechanism for improving the performance of evaluativemore » and professional control mechanisms, the UK Institute of Environmental Management and Assessments' EIA Quality Mark. We do this by defining dimensions of effectiveness for the purposes of our evaluation, and by identifying international examples of the approaches taken to delivering the other control measures to validate the approach taken in the EIA Quality Mark. We then evaluate the EIA Quality Mark, when used in combination with legal procedures and an active judiciary, against the effectiveness dimensions and use time-series analysis of registrant data to examine its ability to progress practice. We conclude that the EIA Quality Mark has merit as a model for a market-based mechanism, and may prove a more financially palatable approach for delivering effective EIA in mature systems in countries that lack centralised agency oversight. It may, therefore, be of particular interest to some Member States of the European Union for ensuring forthcoming certification requirements stemming from recent amendments to the EIA Directive. - Highlights: • Quality control mechanisms in EIA are identified. • Effectiveness of EIA is conceptualised for evaluation purposes. • The UK IEMA EIA Quality Mark is introduced as a market-based mechanism. • The EIA Quality Mark is found to progress quality in many, but not all, areas.« less

Eccentric overload training for patients with chronic Achilles tendon pain--a randomised controlled study with reliability testing of the evaluation methods.

PubMed

Silbernagel, K G; Thomeé, R; Thomeé, P; Karlsson, J

2001-08-01

The purpose was to examine the reliability of measurement techniques and evaluate the effect of a treatment protocol including eccentric overload for patients with chronic pain from the Achilles tendon. Thirty-two patients with proximal achillodynia (44 involved Achilles tendons) participated in tests for reliability measures. No significant differences and strong (r=0.56-0.72) or very strong (r=0.90-0.93) correlations were found between pre-tests, except for the documentation of pain at rest (P<0.008, r=0.45). To evaluate the effect of a 12-week treatment protocol for patients with chronic proximal achillodynia (pain longer than three months) 40 patients (57 involved Achilles tendons) with a mean age of 45 years (range 19-77) were randomised into an experiment group (n=22) and a control group (n=18). Evaluations were performed after six weeks of treatment and after three and six months. The evaluations (including the pre-tests), performed by a physical therapist unaware of the group the patients belonged to, consisted of a questionnaire, a range of motion test, a jumping test, a toe-raise test, a pain on palpation test and pain evaluation during jumping, toe-raises and at rest. A follow-up was also performed after one year. There were no significant differences between groups at any of the evaluations, except that the experiment group jumped significantly lower than the control group at the six-week evaluation. There was, however, an overall better result for the experiment group with significant improvements in plantar flexion, and reduction in pain on palpation, number of patients having pain during walking, having periods when asymptomatic and having swollen Achilles tendon. The controls did not show such changes. Furthermore, at the one-year follow-up there were significantly more patients in the experiment group, compared with the control group, that were satisfied with their present physical activity level, considered themselves fully recovered, and had no pain during or after physical activity. The measurement techniques and the treatment protocol with eccentric overload used in the present study can be recommended for patients with chronic pain from the Achilles tendon.

A Method for Evaluation of Microcomputers for Tactical Applications.

DTIC Science & Technology

1980-06-01

application. The computational requirements of a tactical application are specified in terms of performance parameters. The presently marketed microcomputer...computational requirements of a tactical application are specified in terms of performance parameters. The presently marketed microcomputer and multi...also to provide a method to evaluate microcomputer systems for tactical applications, i.e., Command Control Communications (C 3), weapon systems, etc

Interaction Metrics for Feedback Control of Sound Radiation from Stiffened Panels

NASA Technical Reports Server (NTRS)

Cabell, Randolph H.; Cox, David E.; Gibbs, Gary P.

2003-01-01

Interaction metrics developed for the process control industry are used to evaluate decentralized control of sound radiation from bays on an aircraft fuselage. The metrics are applied to experimentally measured frequency response data from a model of an aircraft fuselage. The purpose is to understand how coupling between multiple bays of the fuselage can destabilize or limit the performance of a decentralized active noise control system. The metrics quantitatively verify observations from a previous experiment, in which decentralized controllers performed worse than centralized controllers. The metrics do not appear to be useful for explaining control spillover which was observed in a previous experiment.

Experimental Evaluation of High Performance Integrated Heat Pump

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

Miller, William A; Berry, Robert; Durfee, Neal

2016-01-01

Integrated heat pump (IHP) technology provides significant potential for energy savings and comfort improvement for residential buildings. In this study, we evaluate the performance of a high performance IHP that provides space heating, cooling, and water heating services. Experiments were conducted according to the ASHRAE Standard 206-2013 where 24 test conditions were identified in order to evaluate the IHP performance indices based on the airside performance. Empirical curve fits of the unit s compressor maps are used in conjunction with saturated condensing and evaporating refrigerant conditions to deduce the refrigerant mass flowrate, which, in turn was used to evaluate themore » refrigerant side performance as a check on the airside performance. Heat pump (compressor, fans, and controls) and water pump power were measured separately per requirements of Standard 206. The system was charged per the system manufacturer s specifications. System test results are presented for each operating mode. The overall IHP performance metrics are determined from the test results per the Standard 206 calculation procedures.« less

An algorithm for control system design via parameter optimization. M.S. Thesis

NASA Technical Reports Server (NTRS)

Sinha, P. K.

1972-01-01

An algorithm for design via parameter optimization has been developed for linear-time-invariant control systems based on the model reference adaptive control concept. A cost functional is defined to evaluate the system response relative to nominal, which involves in general the error between the system and nominal response, its derivatives and the control signals. A program for the practical implementation of this algorithm has been developed, with the computational scheme for the evaluation of the performance index based on Lyapunov's theorem for stability of linear invariant systems.

Integrated Resilient Aircraft Control Project Full Scale Flight Validation

NASA Technical Reports Server (NTRS)

Bosworth, John T.

2009-01-01

Objective: Provide validation of adaptive control law concepts through full scale flight evaluation. Technical Approach: a) Engage failure mode - destabilizing or frozen surface. b) Perform formation flight and air-to-air tracking tasks. Evaluate adaptive algorithm: a) Stability metrics. b) Model following metrics. Full scale flight testing provides an ability to validate different adaptive flight control approaches. Full scale flight testing adds credence to NASA's research efforts. A sustained research effort is required to remove the road blocks and provide adaptive control as a viable design solution for increased aircraft resilience.

Performance on the Wechsler Adult Intelligence Scale-III in Japanese patients with schizophrenia.

PubMed

Fujino, Haruo; Sumiyoshi, Chika; Sumiyoshi, Tomiki; Yasuda, Yuka; Yamamori, Hidenaga; Ohi, Kazutaka; Fujimoto, Michiko; Umeda-Yano, Satomi; Higuchi, Arisa; Hibi, Yumiko; Matsuura, Yukako; Hashimoto, Ryota; Takeda, Masatoshi; Imura, Osamu

2014-07-01

Patients with schizophrenia have been reported to perform worse than non-schizophrenic populations on neuropsychological tests, which may be affected by cultural factors. The aim of this study was to examine the performance of a sizable number of patients with schizophrenia on the Japanese version of the Wechsler Adult Intelligence Scale-III (WAIS-III) compared with healthy controls. Performance on the WAIS-III was evaluated in 157 Japanese patients with schizophrenia and in 264 healthy control subjects. All IQ scores and four indices from the WAIS-III were impaired for patients with schizophrenia compared with healthy controls. Processing Speed was markedly disturbed, approximately 2 SD below that of the healthy control group. Among the 13 subtests, Comprehension (z = -1.70, d = 1.55), Digit Symbol Coding (z = -1.84, d = 1.88), and Symbol Search (z = -1.85, d = 1.77) were profoundly impaired relative to the healthy controls. These results indicate that the pattern and degree of impairment, as evaluated by the WAIS-III, in Japanese patients are similar to those previously reported in English-speaking patients and that the deficits of some neuropsychological domains relevant to functional outcomes are universally characteristic of schizophrenia. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

Accelerated development and flight evaluation of active controls concepts for subsonic transport aircraft. Volume 2: AFT C.G. simulation and analysis

NASA Technical Reports Server (NTRS)

Urie, D. M.

1979-01-01

Relaxed static stability and stability augmentation with active controls were investigated for subsonic transport aircraft. Analytical and simulator evaluations were done using a contemporary wide body transport as a baseline. Criteria for augmentation system performance and unaugmented flying qualities were evaluated. Augmentation control laws were defined based on selected frequency response and time history criteria. Flying qualities evaluations were conducted by pilots using a moving base simulator with a transport cab. Static margin and air turbulence intensity were varied in test with and without augmentation. Suitability of a simple pitch control law was verified at neutral static margin in cruise and landing flight tasks. Neutral stability was found to be marginally acceptable in heavy turbulence in both cruise and landing conditions.

ARAMIS project: a more explicit demonstration of risk control through the use of bow-tie diagrams and the evaluation of safety barrier performance.

PubMed

de Dianous, Valérie; Fiévez, Cécile

2006-03-31

Over the last two decades a growing interest for risk analysis has been noted in the industries. The ARAMIS project has defined a methodology for risk assessment. This methodology has been built to help the industrialist to demonstrate that they have a sufficient risk control on their site. Risk analysis consists first in the identification of all the major accidents, assuming that safety functions in place are inefficient. This step of identification of the major accidents uses bow-tie diagrams. Secondly, the safety barriers really implemented on the site are taken into account. The barriers are identified on the bow-ties. An evaluation of their performance (response time, efficiency, and level of confidence) is performed to validate that they are relevant for the expected safety function. At last, the evaluation of their probability of failure enables to assess the frequency of occurrence of the accident. The demonstration of the risk control based on a couple gravity/frequency of occurrence is also possible for all the accident scenarios. During the risk analysis, a practical tool called risk graph is used to assess if the number and the reliability of the safety functions for a given cause are sufficient to reach a good risk control.

School-based sleep education program improves sleep and academic performance of school-age children.

PubMed

Gruber, Reut; Somerville, Gail; Bergmame, Lana; Fontil, Laura; Paquin, Soukaina

2016-05-01

The objective of this study was to develop and evaluate the effectiveness of a school-based sleep education program aimed at improving the sleep and academic performance of school-age children. Using a community-based participatory research approach, we created a school-based sleep education program, "Sleep for Success"™ (SFS), composed of four distinct modules that addressed the children, their family and community, the school staff, and decision makers within the school setting. Implementation was carried out in three elementary schools. Seventy-one students participated in the evaluation of the program. The effectiveness of the SFS program was evaluated using non-randomized controlled before-and-after study groups (intervention and control) assessed over two time points (pre- and post-program implementation). Before (baseline) and after implementation, sleep and academic performance were measured using actigraphy and report card marks, respectively. In the intervention group, true sleep was extended by 18.2 min per night, sleep efficiency improved by 2.3%, and sleep latency was shortened by 2.3 min, and report card grades in mathematics and English improved significantly. No changes were noted in the control group. Participation in the sleep education program was associated with significant improvements in children's sleep and academic performance. Copyright © 2016 Elsevier B.V. All rights reserved.

Improving prospective memory performance with future event simulation in traumatic brain injury patients.

PubMed

Mioni, Giovanna; Bertucci, Erica; Rosato, Antonella; Terrett, Gill; Rendell, Peter G; Zamuner, Massimo; Stablum, Franca

2017-06-01

Previous studies have shown that traumatic brain injury (TBI) patients have difficulties with prospective memory (PM). Considering that PM is closely linked to independent living it is of primary interest to develop strategies that can improve PM performance in TBI patients. This study employed Virtual Week task as a measure of PM, and we included future event simulation to boost PM performance. Study 1 evaluated the efficacy of the strategy and investigated possible practice effects. Twenty-four healthy participants performed Virtual Week in a no strategy condition, and 24 healthy participants performed it in a mixed condition (no strategy - future event simulation). In Study 2, 18 TBI patients completed the mixed condition of Virtual Week and were compared with the 24 healthy controls who undertook the mixed condition of Virtual Week in Study 1. All participants also completed a neuropsychological evaluation to characterize the groups on level of cognitive functioning. Study 1 showed that participants in the future event simulation condition outperformed participants in the no strategy condition, and these results were not attributable to practice effects. Results of Study 2 showed that TBI patients performed PM tasks less accurately than controls, but that future event simulation can substantially reduce TBI-related deficits in PM performance. The future event simulation strategy also improved the controls' PM performance. These studies showed the value of future event simulation strategy in improving PM performance in healthy participants as well as in TBI patients. TBI patients performed PM tasks less accurately than controls, confirming prospective memory impairment in these patients. Participants in the future event simulation condition out-performed participants in the no strategy condition. Future event simulation can substantially reduce TBI-related deficits in PM performance. Future event simulation strategy also improved the controls' PM performance. © 2017 The British Psychological Society.

Design and Evaluation of a Robust PID Controller for a Fully Implantable Artificial Pancreas

PubMed Central

2015-01-01

Treatment of type 1 diabetes mellitus could be greatly improved by applying a closed-loop control strategy to insulin delivery, also known as an artificial pancreas (AP). In this work, we outline the design of a fully implantable AP using intraperitoneal (IP) insulin delivery and glucose sensing. The design process utilizes the rapid glucose sensing and insulin action offered by the IP space to tune a PID controller with insulin feedback to provide safe and effective insulin delivery. The controller was tuned to meet robust performance and stability specifications. An anti-reset windup strategy was introduced to prevent dangerous undershoot toward hypoglycemia after a large meal disturbance. The final controller design achieved 78% of time within the tight glycemic range of 80–140 mg/dL, with no time spent in hypoglycemia. The next step is to test this controller design in an animal model to evaluate the in vivo performance. PMID:26538805

Speech responses and dual-task performance - Better time-sharing or asymmetric transfer?

NASA Technical Reports Server (NTRS)

Vidulich, Michael A.

1988-01-01

The value of speech controls in a dual-task experiment that also evaluated asymmetric transfer effects is considered. There was no evidence of asymmetric transfer in spite of significant effects supporting the advantage of mixing manual and speech responses. The data suggest that speech controls can be used to enhance performance in operational multiple-task environments.

Evaluation of linearly solvable Markov decision process with dynamic model learning in a mobile robot navigation task.

PubMed

Kinjo, Ken; Uchibe, Eiji; Doya, Kenji

2013-01-01

Linearly solvable Markov Decision Process (LMDP) is a class of optimal control problem in which the Bellman's equation can be converted into a linear equation by an exponential transformation of the state value function (Todorov, 2009b). In an LMDP, the optimal value function and the corresponding control policy are obtained by solving an eigenvalue problem in a discrete state space or an eigenfunction problem in a continuous state using the knowledge of the system dynamics and the action, state, and terminal cost functions. In this study, we evaluate the effectiveness of the LMDP framework in real robot control, in which the dynamics of the body and the environment have to be learned from experience. We first perform a simulation study of a pole swing-up task to evaluate the effect of the accuracy of the learned dynamics model on the derived the action policy. The result shows that a crude linear approximation of the non-linear dynamics can still allow solution of the task, despite with a higher total cost. We then perform real robot experiments of a battery-catching task using our Spring Dog mobile robot platform. The state is given by the position and the size of a battery in its camera view and two neck joint angles. The action is the velocities of two wheels, while the neck joints were controlled by a visual servo controller. We test linear and bilinear dynamic models in tasks with quadratic and Guassian state cost functions. In the quadratic cost task, the LMDP controller derived from a learned linear dynamics model performed equivalently with the optimal linear quadratic regulator (LQR). In the non-quadratic task, the LMDP controller with a linear dynamics model showed the best performance. The results demonstrate the usefulness of the LMDP framework in real robot control even when simple linear models are used for dynamics learning.

Performance of particulate containment at nanotechnology workplaces

NASA Astrophysics Data System (ADS)

Lo, Li-Ming; Tsai, Candace S.-J.; Dunn, Kevin H.; Hammond, Duane; Marlow, David; Topmiller, Jennifer; Ellenbecker, Michael

2015-11-01

The evaluation of engineering controls for the production or use of carbon nanotubes (CNTs) was investigated at two facilities. These control assessments are necessary to evaluate the current status of control performance and to develop proper control strategies for these workplaces. The control systems evaluated in these studies included ventilated enclosures, exterior hoods, and exhaust filtration systems. Activity-based monitoring with direct-reading instruments and filter sampling for microscopy analysis were used to evaluate the effectiveness of control measures at study sites. Our study results showed that weighing CNTs inside the biological safety cabinet can have a 37 % reduction on the particle concentration in the worker's breathing zone, and produce a 42 % lower area concentration outside the enclosure. The ventilated enclosures used to reduce fugitive emissions from the production furnaces exhibited good containment characteristics when closed, but they failed to contain emissions effectively when opened during product removal/harvesting. The exhaust filtration systems employed for exhausting these ventilated enclosures did not provide promised collection efficiencies for removing engineered nanomaterials from furnace exhaust. The exterior hoods were found to be a challenge for controlling emissions from machining nanocomposites: the downdraft hood effectively contained and removed particles released from the manual cutting process, but using the canopy hood for powered cutting of nanocomposites created 15-20 % higher ultrafine (<500 nm) particle concentrations at the source and at the worker's breathing zone. The microscopy analysis showed that CNTs can only be found at production sources but not at the worker breathing zones during the tasks monitored.

Transcontinental anaesthesia: a pilot study.

PubMed

Hemmerling, T M; Arbeid, E; Wehbe, M; Cyr, S; Giunta, F; Zaouter, C

2013-05-01

Although telemedicine is one of the key initiatives of the World Health Organization, no study has explored the feasibility and efficacy of teleanaesthesia. This bi-centre pilot study investigates the feasibility of transcontinental anaesthesia. Twenty patients aged ≥ 18 yr undergoing elective thyroid surgery for ≥ 30 min were enrolled in this study. The remote and local set-up was composed of a master-computer (Montreal) and a slave-computer (Pisa). Standard Internet connection, remote desktop control, and video conference software were used. All patients received total i.v. anaesthesia controlled remotely (Montreal). The main outcomes were feasibility, clinical performance, and controller performance of transcontinental anaesthesia. The clinical performance of hypnosis control was the efficacy to maintain bispectral index (BIS) at 45: 'excellent', 'good', 'poor', and 'inadequate' control represented BIS values within 10, from 11 to 20, from 21 to 30, or >30% from target. The clinical performance of analgesia was the efficacy to maintain Analgoscore values at 0 (-9 to 9); -3 to +3 representing 'excellent' pain control, -3 to -6 and +3 to +6 representing 'good' pain control, and -6 to -9 and +6 to +9 representing 'insufficient' pain control. The controller performance was evaluated using Varvel parameters. Transcontinental anaesthesia was successful in all 20 consecutive patients. The clinical performance of hypnosis showed an 'excellent and good' control for 69% of maintenance time, and the controller performance showed an average global performance index of 57. The clinical performance of analgesia was 'excellent and good' for 92% of maintenance time, and the controller performance showed a global performance index of 1118. Transcontinental anaesthesia is feasible; control of anaesthesia shows good performance indexes. Clinical registration number NCT01331096.

An Opinion of the Relationship Between Outpatient Department Organization and Evaluation of Clinical Competency

ERIC Educational Resources Information Center

Scherer, Paul R.

1978-01-01

Observations of a departmental and non-departmental outpatient service organization are compared regarding student attitude and evaluation, patient care, clinical exposure control, and faculty attitude and performance. Tables show the evaluation topics of each rotation in the departmental system. (LBH)

Evaluation of warning lights on maintenance of traffic devices and development of possible alternatives.

DOT National Transportation Integrated Search

2013-07-01

This report documents the efforts and results of a number of studies and evaluations performed by TTI : researchers to evaluate the effect and value of steady-burn warning lights on temporary traffic control : devices used to delineate the correct tr...

Performance evaluation of the Personal Mobility and Manipulation Appliance (PerMMA).

PubMed

Wang, Hongwu; Xu, Jijie; Grindle, Garrett; Vazquez, Juan; Salatin, Ben; Kelleher, Annmarie; Ding, Dan; Collins, Diane M; Cooper, Rory A

2013-11-01

The Personal Mobility and Manipulation Appliance (PerMMA) is a recently developed personal assistance robot created to provide people with severe physical disabilities enhanced assistance in both mobility and manipulation. PerMMA aims to improve functional independence when a personal care attendant is not available on site. PerMMA integrates both a smart powered wheelchair and two dexterous robotic arms to assist its users in completing essential mobility and manipulation tasks during basic and instrumental activities of daily living (ADL). Two user interfaces were developed: a local control interface and a remote operator controller. This paper reports on the evaluation of PerMMA with end users completing basic ADL tasks. Participants with both lower and upper extremity impairments (N=15) were recruited to operate PerMMA and complete up to five ADL tasks in a single session of no more than two hours (to avoid fatigue or frustration of the participants). The performance of PerMMA was evaluated by participants completing ADL tasks with two different control modes: local mode and cooperative control. The users' task completion performance and answers on pre/post-evaluation questionnaires demonstrated not only the ease in learning and usefulness of PerMMA, but also their attitudes toward assistance from advanced technology like PerMMA. As a part of the iterative development process, results of this work will serve as supporting evidence to identify design criteria and other areas for improvement of PerMMA. Copyright © 2013 IPEM. All rights reserved.

Field testing of particulate matter continuous emission monitors at the DOE Oak Ridge TSCA incinerator. Toxic Substances Control Act.

PubMed

Dunn, James E; Davis, Wayne T; Calcagno, James A; Allen, Marshall W

2002-01-01

A field study to evaluate the performance of three commercially available particulate matter (PM) continuous emission monitors (CEMs) was conducted in 1999-2000 at the US Department of Energy (DOE) Toxic Substances Control Act (TSCA) Incinerator. This study offers unique features that are believed to enhance the collective US experience with PM CEMs. The TSCA Incinerator is permitted to treat PCB-contaminated RCRA hazardous low-level radioactive wastes. The air pollution control system utilizes MACT control technology and is comprised of a rapid quench, venturi scrubber, packed bed scrubber, and two ionizing wet scrubbers in series, which create a saturated flue gas that must be conditioned by the CEMs prior to measurement. The incinerator routinely treats a wide variety of wastes including high and low BTU organic liquids, aqueous, and solid wastes. The various possible combinations for treating liquid and solid wastes may present a challenge in establishing a single, acceptable correlation relationship for individual CEMs. The effect of low-level radioactive material present in the waste is a unique site-specific factor not evaluated in previous tests. The three systems chosen for evaluation were two beta gauge devices and a light scattering device. The performance of the CEMs was evaluated using the requirements in draft Environmental Protection Agency (EPA) Performance Specification 11 (PS11) and Procedure 2. The results of Reference Method 5i stack tests for establishing statistical correlations between the reference method data and the CEMs responses are discussed.

The effects of music on the cardiac resuscitation education of nursing students.

PubMed

Tastan, Sevinc; Ayhan, Hatice; Unver, Vesile; Cinar, Fatma Ilknur; Kose, Gulsah; Basak, Tulay; Cinar, Orhan; Iyigun, Emine

2017-03-01

The purpose of this study is to examine the effects of music on the appropriate performance of the rate and depth of chest compression for nursing students. This randomized controlled study was conducted in the School of Nursing in Turkey between November 2014 and January 2015. The study's participants were second-year nursing school students with no previous formal cardiac resuscitation training (n=77). Participants were randomly assigned to one of two groups: an intervention group with music and a control group without music. During practical training, the intervention group performed chest compressions with music. The outcomes of this study were collected twice. The first evaluation was conducted one day after CPR education, and the second evaluation was conducted six weeks after the initial training. The first evaluation shows that the participants in the intervention group had an average rate of 107.33±7.29 chest compressions per minute, whereas the rate for the control group was 121.47±12.91. The second evaluation shows that the rates of chest compression for the intervention and control groups were 106.24±8.72 and 100.71±9.54, respectively. The results of this study show that a musical piece enables students to remember the ideal rhythm for chest compression. Performing chest compression with music can easily be integrated into CPR education because it does not require additional technology and is cheap. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluating the Specificity of Cognitive Control Deficits in Schizophrenia Using Antisaccades, Functional Magnetic Resonance Imaging, and Healthy Individuals With Poor Cognitive Control.

PubMed

Rodrigue, Amanda L; Schaeffer, David J; Pierce, Jordan E; Clementz, Brett A; McDowell, Jennifer E

2018-01-01

Cognitive control impairments in schizophrenia (SZ) can be evaluated using antisaccade tasks and functional magnetic resonance imaging (fMRI). Studies, however, often compare people with SZ to high performing healthy people, making it unclear if antisaccade-related disruptions are specific to the disease or due to generalized deficits in cognitive control. We included two healthy comparison groups in addition to people with SZ: healthy people with high cognitive control (HCC), who represent a more typical comparison group, and healthy people with low cognitive control (LCC), who perform similarly on antisaccade measures as people with SZ. Using two healthy comparison groups may help determine which antisaccade-related deficits are specific to SZ (distinguish SZ from LCC and HCC groups) and which are due to poor cognitive control (distinguish the LCC and SZ groups from the HCC group). People with SZ and healthy people with HCC or LCC performed an antisaccade task during fMRI acquisition. LCC and SZ groups showed under-activation of saccade circuitry. SZ-specific disruptions were observed in the left superior temporal gyrus and insula during error trials (suppression of activation in the SZ group compared to the LCC and HCC group). Differences related to antisaccade errors may distinguish people with SZ from healthy people with LCC.

Implementation of statistical process control for proteomic experiments via LC MS/MS.

PubMed

Bereman, Michael S; Johnson, Richard; Bollinger, James; Boss, Yuval; Shulman, Nick; MacLean, Brendan; Hoofnagle, Andrew N; MacCoss, Michael J

2014-04-01

Statistical process control (SPC) is a robust set of tools that aids in the visualization, detection, and identification of assignable causes of variation in any process that creates products, services, or information. A tool has been developed termed Statistical Process Control in Proteomics (SProCoP) which implements aspects of SPC (e.g., control charts and Pareto analysis) into the Skyline proteomics software. It monitors five quality control metrics in a shotgun or targeted proteomic workflow. None of these metrics require peptide identification. The source code, written in the R statistical language, runs directly from the Skyline interface, which supports the use of raw data files from several of the mass spectrometry vendors. It provides real time evaluation of the chromatographic performance (e.g., retention time reproducibility, peak asymmetry, and resolution), and mass spectrometric performance (targeted peptide ion intensity and mass measurement accuracy for high resolving power instruments) via control charts. Thresholds are experiment- and instrument-specific and are determined empirically from user-defined quality control standards that enable the separation of random noise and systematic error. Finally, Pareto analysis provides a summary of performance metrics and guides the user to metrics with high variance. The utility of these charts to evaluate proteomic experiments is illustrated in two case studies.

Performance of Optimized Actuator and Sensor Arrays in an Active Noise Control System

NASA Technical Reports Server (NTRS)

Palumbo, D. L.; Padula, S. L.; Lyle, K. H.; Cline, J. H.; Cabell, R. H.

1996-01-01

Experiments have been conducted in NASA Langley's Acoustics and Dynamics Laboratory to determine the effectiveness of optimized actuator/sensor architectures and controller algorithms for active control of harmonic interior noise. Tests were conducted in a large scale fuselage model - a composite cylinder which simulates a commuter class aircraft fuselage with three sections of trim panel and a floor. Using an optimization technique based on the component transfer functions, combinations of 4 out of 8 piezoceramic actuators and 8 out of 462 microphone locations were evaluated against predicted performance. A combinatorial optimization technique called tabu search was employed to select the optimum transducer arrays. Three test frequencies represent the cases of a strong acoustic and strong structural response, a weak acoustic and strong structural response and a strong acoustic and weak structural response. Noise reduction was obtained using a Time Averaged/Gradient Descent (TAGD) controller. Results indicate that the optimization technique successfully predicted best and worst case performance. An enhancement of the TAGD control algorithm was also evaluated. The principal components of the actuator/sensor transfer functions were used in the PC-TAGD controller. The principal components are shown to be independent of each other while providing control as effective as the standard TAGD.

The use of vestibular models for design and evaluation of flight simulator motion

NASA Technical Reports Server (NTRS)

Bussolari, Steven R.; Young, Laurence R.; Lee, Alfred T.

1989-01-01

Quantitative models for the dynamics of the human vestibular system are applied to the design and evaluation of flight simulator platform motion. An optimal simulator motion control algorithm is generated to minimize the vector difference between perceived spatial orientation estimated in flight and in simulation. The motion controller has been implemented on the Vertical Motion Simulator at NASA Ames Research Center and evaluated experimentally through measurement of pilot performance and subjective rating during VTOL aircraft simulation. In general, pilot performance in a longitudinal tracking task (formation flight) did not appear to be sensitive to variations in platform motion condition as long as motion was present. However, pilot assessment of motion fidelity by means of a rating scale designed for this purpose, were sensitive to motion controller design. Platform motion generated with the optimal motion controller was found to be generally equivalent to that generated by conventional linear crossfeed washout. The vestibular models are used to evaluate the motion fidelity of transport category aircraft (Boeing 727) simulation in a pilot performance and simulator acceptability study at the Man-Vehicle Systems Research Facility at NASA Ames Research Center. Eighteen airline pilots, currently flying B-727, were given a series of flight scenarios in the simulator under various conditions of simulator motion. The scenarios were chosen to reflect the flight maneuvers that these pilots might expect to be given during a routine pilot proficiency check. Pilot performance and subjective rating of simulator fidelity was relatively insensitive to the motion condition, despite large differences in the amplitude of motion provided. This lack of sensitivity may be explained by means of the vestibular models, which predict little difference in the modeled motion sensations of the pilots when different motion conditions are imposed.

Early crisis nontechnical skill teaching in residency leads to long-term skill retention and improved performance during crises: A prospective, nonrandomized controlled study.

PubMed

Doumouras, Aristithes G; Engels, Paul T

2017-07-01

Medical error is common in crises, and the majority of observed errors are nontechnical in nature. The long-term impact of teaching crisis nontechnical skills to residents has not been evaluated. The objective of this study was to determine the effect of simulation-based teaching of crisis nontechnical skills compared to controls one year after initial teaching. This was a prospective study using both historical controls and a before-and-after methodology to evaluate the effect of a high-fidelity simulation curriculum that used crisis resource management principles to teach nontechnical skills. Postgraduate year 2 and 3 residents were invited to take part in a prospective training course over 2 years. The primary outcome was leader performance evaluated by expert raters using the previously validated 7-point Ottawa Global Rating Scale. Overall, 23 residents performed 30 simulations over the 2 years with the intervention group of 7 residents being assessed in both years. After adjustment, the postgraduate year 3 intervention group who received training the previous year had significantly higher overall performance scores than all postgraduate year 2 scores (1.09 95% confidence interval 0.70-1.47, P < .001) and the historical postgraduate year 3 cohort who received no prior training (1.20, 95% confidence interval 0.37-2.03, P = .005). There was no decay of skills noted over the course of the study. Postgraduate year 3 residents who had prior training had significantly improved crisis performance compared to historical postgraduate year 3 controls and untrained postgraduate year 2 residents. There were no significant differences between the crisis performance of postgraduate year 2 residents and the untrained postgraduate year 3 controls. This confirms the beneficial effect and long-term retention after crisis nontechnical skill training. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative Evaluation of Energy Measurement Models for Transit Systems

DOT National Transportation Integrated Search

1984-02-01

Recent advances in solid state control technology have led to chopper-controlled propulsion systems in urban rail transit applications. Such systems offer the potential for superior train performance through increased train propulsion efficiency and ...

21 CFR 314.126 - Adequate and well-controlled studies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... permits a valid comparison with a control to provide a quantitative assessment of drug effect. The... data analyses performed. (c) The Director of the Center for Drug Evaluation and Research may, on the...

21 CFR 314.126 - Adequate and well-controlled studies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... permits a valid comparison with a control to provide a quantitative assessment of drug effect. The... data analyses performed. (c) The Director of the Center for Drug Evaluation and Research may, on the...

21 CFR 314.126 - Adequate and well-controlled studies.

Code of Federal Regulations, 2013 CFR

2013-04-01

... permits a valid comparison with a control to provide a quantitative assessment of drug effect. The... data analyses performed. (c) The Director of the Center for Drug Evaluation and Research may, on the...

21 CFR 314.126 - Adequate and well-controlled studies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... permits a valid comparison with a control to provide a quantitative assessment of drug effect. The... data analyses performed. (c) The Director of the Center for Drug Evaluation and Research may, on the...

21 CFR 314.126 - Adequate and well-controlled studies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... permits a valid comparison with a control to provide a quantitative assessment of drug effect. The... data analyses performed. (c) The Director of the Center for Drug Evaluation and Research may, on the...

Altitude Wind Tunnel Investigation of XJ34-WE-32 Engine Performance Without Electronic Control

NASA Technical Reports Server (NTRS)

Bloomer, Harry E; Walker, William J; Pantages, George L

1953-01-01

An investigation was conducted in the NACA Lewis altitude wind tunnel to evaluate the performance characteristics of an XJ34-WE-32 turbojet engine which was equipped with an afterburner, a variable-area exhaust nozzle, and an integrated electronic control. The data were obtained with the afterburner and electronic control inoperative. Performance data were obtained at altitudes from 5000 to 55,000 feet and flight Mach numbers from 0.28 to 1.06 for a complete range of operable engine speeds at each of four fixed positions of the variable-area exhaust nozzle.

Cognitive inhibition in students with and without dyslexia and dyscalculia.

PubMed

Wang, Li-Chih; Tasi, Hung-Ju; Yang, Hsien-Ming

2012-01-01

The present study presents a comparison of the cognitive inhibition abilities of dyslexic, dyscalculic, and control students. The participants were 45 dyslexic students, 45 dyscalculic students, and 45 age-, gender-, and IQ-matched control students. The major evaluation tools included six cognitive inhibition tasks which were restructured during principal component analysis into three categories: graph inhibition, number inhibition, and word inhibition. Comparisons of the 3 groups of students revealed that in graph inhibition, dyscalculic students performed worst of the 3 groups, with dyslexic students also performing worse than control students in this category. For number inhibition, the control students' performances were equal to those of dyslexic students, with both groups performing better than dyscalculic students. For word inhibition, control students' performances were equal to those of dyscalculic students; both groups had shorter response times and lower incorrect rates than dyslexic students. These results suggest the complexity of the different cognitive inhibition abilities displayed by dyslexic, dyscalculic, and control students. However, some regular patterns occurred. Copyright © 2012 Elsevier Ltd. All rights reserved.

Managing Performance Evaluation Uncertainties in Schools: When Teachers Become Struggling Performers

ERIC Educational Resources Information Center

Englund, Hans; Frostenson, Magnus

2017-01-01

Performative technologies are increasingly relied upon as a means of controlling the work of teachers. As noted in the literature, one possible outcome of this trend is the performer, a teacher identity that presupposes the internalization of, and adaptation to, a performative logic. Based on the findings from an empirical study of a Swedish upper…

Handling Qualities of Model Reference Adaptive Controllers with Varying Complexity for Pitch-Roll Coupled Failures

NASA Technical Reports Server (NTRS)

Schaefer, Jacob; Hanson, Curt; Johnson, Marcus A.; Nguyen, Nhan

2011-01-01

Three model reference adaptive controllers (MRAC) with varying levels of complexity were evaluated on a high performance jet aircraft and compared along with a baseline nonlinear dynamic inversion controller. The handling qualities and performance of the controllers were examined during failure conditions that induce coupling between the pitch and roll axes. Results from flight tests showed with a roll to pitch input coupling failure, the handling qualities went from Level 2 with the baseline controller to Level 1 with the most complex MRAC tested. A failure scenario with the left stabilator frozen also showed improvement with the MRAC. Improvement in performance and handling qualities was generally seen as complexity was incrementally added; however, added complexity usually corresponds to increased verification and validation effort required for certification. The tradeoff between complexity and performance is thus important to a controls system designer when implementing an adaptive controller on an aircraft. This paper investigates this relation through flight testing of several controllers of vary complexity.

Control Chart on Semi Analytical Weighting

NASA Astrophysics Data System (ADS)

Miranda, G. S.; Oliveira, C. C.; Silva, T. B. S. C.; Stellato, T. B.; Monteiro, L. R.; Marques, J. R.; Faustino, M. G.; Soares, S. M. V.; Ulrich, J. C.; Pires, M. A. F.; Cotrim, M. E. B.

2018-03-01

Semi-analytical balance verification intends to assess the balance performance using graphs that illustrate measurement dispersion, trough time, and to demonstrate measurements were performed in a reliable manner. This study presents internal quality control of a semi-analytical balance (GEHAKA BG400) using control charts. From 2013 to 2016, 2 weight standards were monitored before any balance operation. This work intended to evaluate if any significant difference or bias were presented on weighting procedure over time, to check the generated data reliability. This work also exemplifies how control intervals are established.

Design and Analysis of Precise Pointing Systems

NASA Technical Reports Server (NTRS)

Kim, Young K.

2000-01-01

The mathematical models of Glovebox Integrated Microgravity Isolation Technology (g- LIMIT) dynamics/control system, which include six degrees of freedom (DOF) equations of motion, mathematical models of position sensors, accelerometers and actuators, and acceleration and position controller, were developed using MATLAB and TREETOPS simulations. Optimal control parameters of G-LIMIT control system were determined through sensitivity studies and its performance were evaluated with the TREETOPS model of G-LIMIT dynamics and control system. The functional operation and performance of the Tektronix DTM920 digital thermometer were studied and the inputs to the crew procedures and training of the DTM920 were documented.

Fuzzy regulator design for wind turbine yaw control.

PubMed

Theodoropoulos, Stefanos; Kandris, Dionisis; Samarakou, Maria; Koulouras, Grigorios

2014-01-01

This paper proposes the development of an advanced fuzzy logic controller which aims to perform intelligent automatic control of the yaw movement of wind turbines. The specific fuzzy controller takes into account both the wind velocity and the acceptable yaw error correlation in order to achieve maximum performance efficacy. In this way, the proposed yaw control system is remarkably adaptive to the existing conditions. In this way, the wind turbine is enabled to retain its power output close to its nominal value and at the same time preserve its yaw system from pointless movement. Thorough simulation tests evaluate the proposed system effectiveness.

Predicted performance benefits of an adaptive digital engine control system of an F-15 airplane

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Myers, L. P.; Ray, R. J.

1985-01-01

The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrating engine-airframe control systems. Currently this is accomplished on the NASA Ames Research Center's F-15 airplane. The two control modes used to implement the systems are an integrated flightpath management mode and in integrated adaptive engine control system (ADECS) mode. The ADECS mode is a highly integrated mode in which the airplane flight conditions, the resulting inlet distortion, and the available engine stall margin are continually computed. The excess stall margin is traded for thrust. The predicted increase in engine performance due to the ADECS mode is presented in this report.

Performance Evaluation of Hot Mix Asphalt with Different Proportions of RAP Content

NASA Astrophysics Data System (ADS)

Kamil Arshad, Ahmad; Awang, Haryati; Shaffie, Ekarizan; Hashim, Wardati; Rahman, Zanariah Abd

2018-03-01

Reclaimed Asphalt Pavement (RAP) is old asphalt pavement that has been removed from a road by milling or full depth removal. The use of RAP in hot mix asphalt (HMA) eliminates the need to dispose old asphalt pavements and conserves asphalt binders and aggregates, resulting in significant cost savings and benefits to society. This paper presents a study on HMA with different RAP proportions carried out to evaluate the volumetric properties and performance of asphalt mixes containing different proportions of RAP. Marshall Mix Design Method was used to produce control mix (0% RAP) and asphalt mixes containing 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia for AC14 dense graded asphalt gradation. Volumetric analysis was performed to ensure that the result is compliance with specification requirements. The resilient modulus test was performed to measure the stiffness of the mixes while the Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The Hamburg wheel tracking test was used to evaluate the rutting performance of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility, resilient modulus and rutting resistance between asphalt mixes with RAP and the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% RAP material.

Comparative Simulation Study of Glucose Control Methods Designed for Use in the Intensive Care Unit Setting via a Novel Controller Scoring Metric.

PubMed

DeJournett, Jeremy; DeJournett, Leon

2017-11-01

Effective glucose control in the intensive care unit (ICU) setting has the potential to decrease morbidity and mortality rates and thereby decrease health care expenditures. To evaluate what constitutes effective glucose control, typically several metrics are reported, including time in range, time in mild and severe hypoglycemia, coefficient of variation, and others. To date, there is no one metric that combines all of these individual metrics to give a number indicative of overall performance. We proposed a composite metric that combines 5 commonly reported metrics, and we used this composite metric to compare 6 glucose controllers. We evaluated the following controllers: Ideal Medical Technologies (IMT) artificial-intelligence-based controller, Yale protocol, Glucommander, Wintergerst et al PID controller, GRIP, and NICE-SUGAR. We evaluated each controller across 80 simulated patients, 4 clinically relevant exogenous dextrose infusions, and one nonclinical infusion as a test of the controller's ability to handle difficult situations. This gave a total of 2400 5-day simulations, and 585 604 individual glucose values for analysis. We used a random walk sensor error model that gave a 10% MARD. For each controller, we calculated severe hypoglycemia (<40 mg/dL), mild hypoglycemia (40-69 mg/dL), normoglycemia (70-140 mg/dL), hyperglycemia (>140 mg/dL), and coefficient of variation (CV), as well as our novel controller metric. For the controllers tested, we achieved the following median values for our novel controller scoring metric: IMT: 88.1, YALE: 46.7, GLUC: 47.2, PID: 50, GRIP: 48.2, NICE: 46.4. The novel scoring metric employed in this study shows promise as a means for evaluating new and existing ICU-based glucose controllers, and it could be used in the future to compare results of glucose control studies in critical care. The IMT AI-based glucose controller demonstrated the most consistent performance results based on this new metric.

Performance of recycled mixtures in state of Georgia.

DOT National Transportation Integrated Search

1994-01-01

The Georgia Department of Transportation (GDOT) has been constructing recycled asphalt pavements routinely for about four years. This research project was undertaken to evaluate the performance of recycled pavements in comparison to virgin (control) ...

On the tip of the tongue: learning typing and pointing with an intra-oral computer interface.

PubMed

Caltenco, Héctor A; Breidegard, Björn; Struijk, Lotte N S Andreasen

2014-07-01

To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control. Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users. Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.

Motion Perception and Manual Control Performance During Passive Tilt and Translation Following Space Flight

NASA Technical Reports Server (NTRS)

Clement, Gilles; Wood, Scott J.

2010-01-01

This joint ESA-NASA study is examining changes in motion perception following Space Shuttle flights and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data has been collected on 5 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s) combined with body translation (12-22 cm, peak-to-peak) is utilized to elicit roll-tilt perception (equivalent to 20 deg, peak-to-peak). A forward-backward moving sled (24-390 cm, peak-to-peak) with or without chair tilting in pitch is utilized to elicit pitch tilt perception (equivalent to 20 deg, peak-to-peak). These combinations are elicited at 0.15, 0.3, and 0.6 Hz for evaluating the effect of motion frequency on tilt-translation ambiguity. In both devices, a closed-loop nulling task is also performed during pseudorandom motion with and without vibrotactile feedback of tilt. All tests are performed in complete darkness. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for translation motion perception to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. The results of this study indicate that post-flight recovery of motion perception and manual control performance is complete within 8 days following short-duration space missions. Vibrotactile feedback of tilt improves manual control performance both before and after flight.

Strategic avionics technology definition studies. Subtask 3-1A3: Electrical Actuation (ELA) Systems Test Facility

NASA Technical Reports Server (NTRS)

Rogers, J. P.; Cureton, K. L.; Olsen, J. R.

1994-01-01

Future aerospace vehicles will require use of the Electrical Actuator systems for flight control elements. This report presents a proposed ELA Test Facility for dynamic evaluation of high power linear Electrical Actuators with primary emphasis on Thrust Vector Control actuators. Details of the mechanical design, power and control systems, and data acquisition capability of the test facility are presented. A test procedure for evaluating the performance of the ELA Test Facility is also included.

A Prospective Evaluation of Duplex Ultrasound for Thoracic Outlet Syndrome in High-Performance Musicians Playing Bowed String Instruments

PubMed Central

Adam, Garret; Wang, Kevin; Demaree, Christopher J.; Jiang, Jenny S.; Cheung, Mathew; Bechara, Carlos F.

2018-01-01

Thoracic outlet syndrome (TOS) is a neurovascular condition involving the upper extremity, which is known to occur in individuals who perform chronic repetitive upper extremity activities. We prospectively evaluate the incidence of TOS in high-performance musicians who played bowed string musicians. Sixty-four high-performance string instrument musicians from orchestras and professional musical bands were included in the study. Fifty-two healthy volunteers formed an age-matched control group. Bilateral upper extremity duplex scanning for subclavian vessel compression was performed in all subjects. Provocative maneuvers including Elevated Arm Stress Test (EAST) and Upper Limb Tension Test (ULTT) were performed. Abnormal ultrasound finding is defined by greater than 50% subclavian vessel compression with arm abduction, diminished venous waveforms, or arterial photoplethysmography (PPG) tracing with arm abduction. Bowed string instruments performed by musicians in our study included violin (41%), viola (33%), and cello (27%). Positive EAST or ULTT test in the musician group and control group were 44%, and 3%, respectively (p = 0.03). Abnormal ultrasound scan with vascular compression was detected in 69% of musicians, in contrast to 15% of control subjects (p = 0.03). TOS is a common phenomenon among high-performance bowed string instrumentalists. Musicians who perform bowed string instruments should be aware of this condition and its associated musculoskeletal symptoms. PMID:29370085

Evaluation of the hypertension disease management program in Korea.

PubMed

Kim, Younmi; Lee, Kunsei; Shin, Eunyoung; Kim, Hyeongsu; June, Kyung Ja

2010-07-01

This study evaluated how the Hypertension Disease Management Program (HDMP) affects patient's blood pressure, knowledge, health behaviors, and use of medical services. Evaluation was performed by 2 measures, which were before and after comparison within the management group (n = 210) and comparison between the management group and control group (n = 1050) in 2005. Systolic and diastolic blood pressure of management group significantly decreased from 137.5 and 86.0 mm Hg to 131.2 and 83.8 mm Hg (P < .001, P < .01), respectively. Dieting, snack control, consumption of low-sodium meals, low-cholesterol meals, and fruits or vegetables, regular checking of blood pressure, and stress management techniques significantly increased after HDMP. However, there was no significant difference in the use of medical service between the disease management group and the control group. This study showed that the HDMP improved lifestyle and reduced blood pressure on the disease management group, but changed neither medical costs nor use of medical services. Long-term evaluation should be performed to determine if the HDMP reduce medical costs and use of medical services.

A Literature Survey and Experimental Evaluation of the State-of-the-Art in Uplift Modeling: A Stepping Stone Toward the Development of Prescriptive Analytics.

PubMed

Devriendt, Floris; Moldovan, Darie; Verbeke, Wouter

2018-03-01

Prescriptive analytics extends on predictive analytics by allowing to estimate an outcome in function of control variables, allowing as such to establish the required level of control variables for realizing a desired outcome. Uplift modeling is at the heart of prescriptive analytics and aims at estimating the net difference in an outcome resulting from a specific action or treatment that is applied. In this article, a structured and detailed literature survey on uplift modeling is provided by identifying and contrasting various groups of approaches. In addition, evaluation metrics for assessing the performance of uplift models are reviewed. An experimental evaluation on four real-world data sets provides further insight into their use. Uplift random forests are found to be consistently among the best performing techniques in terms of the Qini and Gini measures, although considerable variability in performance across the various data sets of the experiments is observed. In addition, uplift models are frequently observed to be unstable and display a strong variability in terms of performance across different folds in the cross-validation experimental setup. This potentially threatens their actual use for business applications. Moreover, it is found that the available evaluation metrics do not provide an intuitively understandable indication of the actual use and performance of a model. Specifically, existing evaluation metrics do not facilitate a comparison of uplift models and predictive models and evaluate performance either at an arbitrary cutoff or over the full spectrum of potential cutoffs. In conclusion, we highlight the instability of uplift models and the need for an application-oriented approach to assess uplift models as prime topics for further research.

A novel integrated approach for path following and directional stability control of road vehicles after a tire blow-out

NASA Astrophysics Data System (ADS)

Wang, Fei; Chen, Hong; Guo, Konghui; Cao, Dongpu

2017-09-01

The path following and directional stability are two crucial problems when a road vehicle experiences a tire blow-out or sudden tire failure. Considering the requirement of rapid road vehicle motion control during a tire blow-out, this article proposes a novel linearized decoupling control procedure with three design steps for a class of second order multi-input-multi-output non-affine system. The evaluating indicators for controller performance are presented and a performance related control parameter distribution map is obtained based on the stochastic algorithm which is an innovation for non-blind parameter adjustment in engineering implementation. The analysis on the robustness of the proposed integrated controller is also performed. The simulation studies for a range of driving conditions are conducted, to demonstrate the effectiveness of the proposed controller.

Effectiveness of crack sealing on pavement serviceability and life.

DOT National Transportation Integrated Search

2011-06-01

This report presents the details of a study to evaluate effectiveness of Ohio Department of Transportations prevailing crack sealing program. Evaluation was performed through field monitoring a large number of crack sealed and control sections. Fi...

Evaluation of multicast schemes in optical burst-switched networks: the case with dynamic sessions

NASA Astrophysics Data System (ADS)

Jeong, Myoungki; Qiao, Chunming; Xiong, Yijun; Vandenhoute, Marc

2000-10-01

In this paper, we evaluate the performance of several multicast schemes in optical burst-switched WDM networks taking into accounts the overheads due to control packets and guard bands (Gbs) of bursts on separate channels (wavelengths). A straightforward scheme is called Separate Multicasting (S-MCAST) where each source node constructs separate bursts for its multicast (per each multicast session) and unicast traffic. To reduce the overhead due to Gbs (and control packets), one may piggyback the multicast traffic in bursts containing unicast traffic using a scheme called Multiple Unicasting (M-UCAST). The third scheme is called Tree-Shared Multicasting (TS-MCAST) wehreby multicast traffic belonging to multiple multicast sesions can be mixed together in a burst, which is delivered via a shared multicast tree. In [1], we have evaluated several multicast schemes with static sessions at the flow level. In this paper, we perform a simple analysis for the multicast schemes and evaluate the performance of three multicast schemes, focusing on the case with dynamic sessions in terms of the link utilization, bandwidth consumption, blocking (loss) probability, goodput and the processing loads.

Evaluation of respiratory system in textile-dyeing workers.

PubMed

Salmani Nodoushan, Mojahede; Mehrparvar, Amir Houshang; Loukzadeh, Ziba; Rahimian, Masoud; Ghove Nodoushan, Mohamad Ali; Jafari Nodoushan, Reza

2014-01-01

Despite the presence of many textile and dyeing plants in Iran, we couldn't find similar studies in this country. Forthermore, considering progress in the dyeing process and engineering controls, assessment of respiratory system is important for these workers. The present study was performed to evaluate the respiratory system in dyeing workers. In a cross-sectional study, 101 dyeing workers (all dyeing workers in yazd) and 90 workers without respiratory exposures (control group), were evaluated. A questionnaire was filled for each participant included Venables questionnaire and some other questions about age, work experience, personal or familial history of asthma or atopy, acute and chronic respiratory symptoms; Then spirometry was performed before and after the shift work Results: The frequency of acute and chronic respiratory symptoms was significantly higher among dyeing workers than controls. According to the Venables questionnaire, 11.9% of the dyeing workers suffered from asthma. Means of FVC and FEV1 of pre-shift spirometry were lower than control (p< 0.001). Across-shift spirometry showed significant reduction of FVC (p< 0.001), FEV1 (p< 0.001), FEF25-75% (p= 0.05) and FEF25% (p= 0.007) in dyeing workers compared to the control group. Evaluation of dyeing workers' respiratory system in this study showed that despite development in dyeing processes and engineering controls, workers in this job show more prevalent acute and chronic symptoms, and across-shift changes in spirometric parameters were significantly higher in this work group than the control group. Therefore it is necessary to pay attention to the control of respiratory exposures in this job.

Risk management in technovigilance: construction and validation of a medical-hospital product evaluation instrument.

PubMed

Kuwabara, Cleuza Catsue Takeda; Evora, Yolanda Dora Martinez; de Oliveira, Márcio Mattos Borges

2010-01-01

With the continuous incorporation of health technologies, hospital risk management should be implemented to systemize the monitoring of adverse effects, performing actions to control and eliminate their damage. As part of these actions, Technovigilance is active in the procedures of acquisition, use and quality control of health products and equipment. This study aimed to construct and validate an instrument to evaluate medical-hospital products. This is a quantitative, exploratory, longitudinal and methodological development study, based on the Six Sigma quality management model, which has as its principle basis the component stages of the DMAIC Cycle. For data collection and content validation, the Delphi technique was used with professionals from the Brazilian Sentinel Hospital Network. It was concluded that the instrument developed permitted the evaluation of the product, differentiating between the results of the tested brands, in line with the initial study goal of qualifying the evaluations performed.

Statistical evaluation of vibration analysis techniques

NASA Technical Reports Server (NTRS)

Milner, G. Martin; Miller, Patrice S.

1987-01-01

An evaluation methodology is presented for a selection of candidate vibration analysis techniques applicable to machinery representative of the environmental control and life support system of advanced spacecraft; illustrative results are given. Attention is given to the statistical analysis of small sample experiments, the quantification of detection performance for diverse techniques through the computation of probability of detection versus probability of false alarm, and the quantification of diagnostic performance.

Automation - Changes in cognitive demands and mental workload

NASA Technical Reports Server (NTRS)

Tsang, Pamela S.; Johnson, Walter W.

1987-01-01

The effect of partial automation on mental workloads in man/machine tasks is investigated experimentally. Subjective workload measures are obtained from six subjects after performance of a task battery comprising two manual (flight-path control, FC, and target acquisition, TA) tasks and one decisionmaking (engine failure, EF) task; the FC task was performed in both a fully manual (altitude and lateral control) mode and in a semiautomated mode (autmatic latitude control). The performance results and subjective evaluations are presented in graphs and characterized in detail. The automation is shown to improve objective performance and lower subjective workload significantly in the combined FC/TA task, but not in the FC task alone or in the FC/EF task.

Intertester and intratester reliability of movement control tests on the hip for patients with hip osteoarthritis.

PubMed

Lenzlinger-Asprion, Rahel; Keller, Niculina; Meichtry, André; Luomajoki, Hannu

2017-01-31

Hip joint complaints are a problem associated with increasing age and impair the mobility of a large section of the elderly population. Reliable and valid tests are necessary for a thorough investigation of a joint. A fundamental function of the hip joint is movement control and a test of this function forms a part of the standard examination. Until now there have been few scientific studies which specifically investigate the reliability of measurement tests of movement control of the hip joint. The aim of this study was to examine the intratester and intertester reliability of the movement control tests of the hip joint which are in use in current clinical practice. Sixteen participants with hip joint complaints and 14 without hip joint impairment were recruited. All participants performed five active movement control tests for the hip joint and were video filmed whilst performing these tests. These films formed the basis for the evaluation and were assessed by two independent physiotherapists. For the intertester and intratester reliability calculations specially set weighted kappa values and the calculated percentages were used. The intertester reliability of the five examined movement control tests of the hip joint showed good to almost perfect values (weighted kappa (wk) = 0.56-0.87). The intratester reliability of the more experienced evaluator A was better in regards to the less experienced evaluator B (average wk = 0.62 vs 0.38). The visual evaluation of movement control tests of the hip joint is especially reliable when carried out by an experienced evaluator. 4 out of 5 tests also showed good results for intertester reliability and support their use in clinical practice.

Examining the Relationship between Employee Satisfaction and Organizational Performance in Higher Education

ERIC Educational Resources Information Center

Dusing, Roger P.

2017-01-01

Organizations, regardless of industry/sector, should consistently evaluate and improve organizational performance. Higher education institutions have come under increasing pressures to control costs while improving outcomes and would benefit from strategies that improve the performance of their employees leading to improved organizational…

Integrated modeling and robust control for full-envelope flight of robotic helicopters

NASA Astrophysics Data System (ADS)

La Civita, Marco

Robotic helicopters have attracted a great deal of interest from the university, the industry, and the military world. They are versatile machines and there is a large number of important missions that they could accomplish. Nonetheless, there are only a handful of documented examples of robotic-helicopter applications in real-world scenarios. This situation is mainly due to the poor flight performance that can be achieved and---more important---guaranteed under automatic control. Given the maturity of control theory, and given the large body of knowledge in helicopter dynamics, it seems that the lack of success in flying high-performance controllers for robotic helicopters, especially by academic groups and by small industries, has nothing to do with helicopters or control theory as such. The problem lies instead in the large amount of time and resources needed to synthesize, test, and implement new control systems with the approach normally followed in the aeronautical industry. This thesis attempts to provide a solution by presenting a modeling and control framework that minimizes the time, cost, and both human and physical resources necessary to design high-performance flight controllers. The work is divided in two main parts. The first consists of the development of a modeling technique that allows the designer to obtain a high-fidelity model adequate for both real-time simulation and controller design, with few flight, ground, and wind-tunnel tests and a modest level of complexity in the dynamic equations. The second consists of the exploitation of the predictive capabilities of the model and of the robust stability and performance guarantees of the Hinfinity loop-shaping control theory to reduce the number of iterations of the design/simulated-evaluation/flight-test-evaluation procedure. The effectiveness of this strategy is demonstrated by designing and flight testing a wide-envelope high-performance controller for the Carnegie Mellon University robotic helicopter.

Performance analysis of different tuning rules for an isothermal CSTR using integrated EPC and SPC

NASA Astrophysics Data System (ADS)

Roslan, A. H.; Karim, S. F. Abd; Hamzah, N.

2018-03-01

This paper demonstrates the integration of Engineering Process Control (EPC) and Statistical Process Control (SPC) for the control of product concentration of an isothermal CSTR. The objectives of this study are to evaluate the performance of Ziegler-Nichols (Z-N), Direct Synthesis, (DS) and Internal Model Control (IMC) tuning methods and determine the most effective method for this process. The simulation model was obtained from past literature and re-constructed using SIMULINK MATLAB to evaluate the process response. Additionally, the process stability, capability and normality were analyzed using Process Capability Sixpack reports in Minitab. Based on the results, DS displays the best response for having the smallest rise time, settling time, overshoot, undershoot, Integral Time Absolute Error (ITAE) and Integral Square Error (ISE). Also, based on statistical analysis, DS yields as the best tuning method as it exhibits the highest process stability and capability.

Design and modeling of new suspension system using direct drive servo-valve system actuated by piezostack actuator

NASA Astrophysics Data System (ADS)

Han, Chulhee; Kim, Wan Ho; Choi, Seung-Bok

2016-04-01

This paper proposes a new type of a direct-drive valve (DDV) suspension system for vehicle controlled by the piezostack actuator associated with displacement amplifier. In order to achieve this goal, a new type of controllable piezostack DDV damper is designed and its performance evaluation of damping force is undertaken. Next, a full vehicle suspension system consisting of sprung mass, spring, tire and the piezostack DDV damper is constructed. After deriving the governing equations of the motion for the proposed the piezostack DDV suspension system, the skyhook controller is implemented for the realization of the full vehicle. Analytical model of the whole suspension system is then derived and performance characteristics are analyzed through numerical simulation. Finally, vibration control responses of the vehicle suspension system such as vertical acceleration are evaluated under both bump and sine road conditions.

Interference of different types of seats on postural control system during a forward-reaching task in individuals with paraplegia.

PubMed

de Abreu, Daniela Cristina Carvalho; Takara, Kelly; Metring, Nathália Lopes; Reis, Júlia Guimarães; Cliquet, Alberto

2012-09-01

We aimed to evaluate the influence of different types of wheelchair seats on paraplegic individuals' postural control using a maximum anterior reaching test. Balance evaluations during 50, 75, and 90% of each individual's maximum reach in the forward direction using two different cushions on seat (one foam and one gel) and a no-cushion condition were carried out on 11 individuals with a spinal cord injury (SCI) and six individuals without SCI. Trunk anterior displacement and the time spent to perform the test were assessed. No differences were found for the three types of seats in terms of trunk anterior displacement and the time spent to perform the test when intragroup comparisons were made in both groups (P>0.05). The intergroup comparison showed that body displacement was less prominent and the time spent to perform the test was more prolonged for individuals with SCI (P<0.05), which suggests a postural control deficit. The seat type did not affect the ability of the postural control system to maintain balance during the forward-reaching task.

Flight Test Results from the NF-15B Intelligent Flight Control System (IFCS) Project with Adaptation to a Simulated Stabilator Failure

NASA Technical Reports Server (NTRS)

Bosworth, John T.; Williams-Hayes, Peggy S.

2007-01-01

Adaptive flight control systems have the potential to be more resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane and subjected to an inflight simulation of a failed (frozen) (unmovable) stabilator. Formation flight handling qualities evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to decouple the roll and pitch response and reestablish good onboard model tracking. Flight evaluation with the simulated stabilator failure and adaptation engaged showed that there was generally improvement in the pitch response; however, a tendency for roll pilot-induced oscillation was experienced. A detailed discussion of the cause of the mixed results is presented.

Flight Test Results from the NF-15B Intelligent Flight Control System (IFCS) Project with Adaptation to a Simulated Stabilator Failure

NASA Technical Reports Server (NTRS)

Bosworth, John T.; Williams-Hayes, Peggy S.

2010-01-01

Adaptive flight control systems have the potential to be more resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane and subjected to an inflight simulation of a failed (frozen) (unmovable) stabilator. Formation flight handling qualities evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to decouple the roll and pitch response and reestablish good onboard model tracking. Flight evaluation with the simulated stabilator failure and adaptation engaged showed that there was generally improvement in the pitch response; however, a tendency for roll pilot-induced oscillation was experienced. A detailed discussion of the cause of the mixed results is presented.

Lay out, test verification and in orbit performance of HELIOS a temperature control system

NASA Technical Reports Server (NTRS)

Brungs, W.

1975-01-01

HELIOS temperature control system is described. The main design features and the impact of interactions between experiment, spacecraft system, and temperature control system requirements on the design are discussed. The major limitations of the thermal design regarding a closer sun approach are given and related to test experience and performance data obtained in orbit. Finally the validity of the test results achieved with prototype and flight spacecraft is evaluated by comparison between test data, orbit temperature predictions and flight data.

Experimental evaluation of HJB optimal controllers for the attitude dynamics of a multirotor aerial vehicle.

PubMed

Prado, Igor Afonso Acampora; Pereira, Mateus de Freitas Virgílio; de Castro, Davi Ferreira; Dos Santos, Davi Antônio; Balthazar, Jose Manoel

2018-06-01

The present paper is concerned with the design and experimental evaluation of optimal control laws for the nonlinear attitude dynamics of a multirotor aerial vehicle. Three design methods based on Hamilton-Jacobi-Bellman equation are taken into account. The first one is a linear control with guarantee of stability for nonlinear systems. The second and third are a nonlinear suboptimal control techniques. These techniques are based on an optimal control design approach that takes into account the nonlinearities present in the vehicle dynamics. The stability Proof of the closed-loop system is presented. The performance of the control system designed is evaluated via simulations and also via an experimental scheme using the Quanser 3-DOF Hover. The experiments show the effectiveness of the linear control method over the nonlinear strategy. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

An iterative learning control method with application for CNC machine tools

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

Kim, D.I.; Kim, S.

1996-01-01

A proportional, integral, and derivative (PID) type iterative learning controller is proposed for precise tracking control of industrial robots and computer numerical controller (CNC) machine tools performing repetitive tasks. The convergence of the output error by the proposed learning controller is guaranteed under a certain condition even when the system parameters are not known exactly and unknown external disturbances exist. As the proposed learning controller is repeatedly applied to the industrial robot or the CNC machine tool with the path-dependent repetitive task, the distance difference between the desired path and the actual tracked or machined path, which is one ofmore » the most significant factors in the evaluation of control performance, is progressively reduced. The experimental results demonstrate that the proposed learning controller can improve machining accuracy when the CNC machine tool performs repetitive machining tasks.« less

Preliminary simulation of an advanced, hingless rotor XV-15 tilt-rotor aircraft

NASA Technical Reports Server (NTRS)

Mcveigh, M. A.

1976-01-01

The feasibility of the tilt-rotor concept was verified through investigation of the performance, stability and handling qualities of the XV-15 tilt rotor. The rotors were replaced by advanced-technology fiberglass/composite hingless rotors of larger diameter, combined with an advanced integrated fly-by-wire control system. A parametric simulation model of the HRXV-15 was developed, model was used to define acceptable preliminary ranges of primary and secondary control schedules as functions of the flight parameters, to evaluate performance, flying qualities and structural loads, and to have a Boeing-Vertol pilot conduct a simulated flight test evaluation of the aircraft.

Performance evaluation of nursing students following competency-based education.

PubMed

Fan, Jun-Yu; Wang, Yu Hsin; Chao, Li Fen; Jane, Sui-Whi; Hsu, Li-Ling

2015-01-01

Competency-based education is known to improve the match between educational performance and employment opportunities. This study examined the effects of competency-based education on the learning outcomes of undergraduate nursing students. The study used a quasi-experimental design. A convenience sample of 312 second-year undergraduate nursing students from northern and southern Taiwan participated in the study. The experimental group (n=163) received competency-based education and the control group received traditional instruction (n=149) in a medical-surgical nursing course. Outcome measures included students' scores on the Objective Structured Clinical Examination, Self-Evaluated Core Competencies Scale, Metacognitive Inventory for Nursing Students questionnaire, and academic performance. Students who received competency-based education had significantly higher academic performance in the medical-surgical nursing course and practicum than did the control group. Required core competencies and metacognitive abilities improved significantly in the competency-based education group as compared to the control group after adjusting for covariates. Competency-based education is worth implementing and may close the gap between education and the ever-changing work environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

IMPAC: An Integrated Methodology for Propulsion and Airframe Control

NASA Technical Reports Server (NTRS)

Garg, Sanjay; Ouzts, Peter J.; Lorenzo, Carl F.; Mattern, Duane L.

1991-01-01

The National Aeronautics and Space Administration is actively involved in the development of enabling technologies that will lead towards aircraft with new/enhanced maneuver capabilities such as Short Take-Off Vertical Landing (STOVL) and high angle of attack performance. Because of the high degree of dynamic coupling between the airframe and propulsion systems of these types of aircraft, one key technology is the integration of the flight and propulsion control. The NASA Lewis Research Center approach to developing Integrated Flight Propulsion Control (IFPC) technologies is an in-house research program referred to as IMPAC (Integrated Methodology for Propulsion and Airframe Control). The goals of IMPAC are to develop a viable alternative to the existing integrated control design methodologies that will allow for improved system performance and simplicity of control law synthesis and implementation, and to demonstrate the applicability of the methodology to a supersonic STOVL fighter aircraft. Based on some preliminary control design studies that included evaluation of the existing methodologies, the IFPC design methodology that is emerging at the Lewis Research Center consists of considering the airframe and propulsion system as one integrated system for an initial centralized controller design and then partitioning the centralized controller into separate airframe and propulsion system subcontrollers to ease implementation and to set meaningful design requirements for detailed subsystem control design and evaluation. An overview of IMPAC is provided and detailed discussion of the various important design and evaluation steps in the methodology are included.

A randomized controlled study to evaluate the role of video-based coaching in training laparoscopic skills.

PubMed

Singh, Pritam; Aggarwal, Rajesh; Tahir, Muaaz; Pucher, Philip H; Darzi, Ara

2015-05-01

This study evaluates whether video-based coaching can enhance laparoscopic surgical skills performance. Many professions utilize coaching to improve performance. The sports industry employs video analysis to maximize improvement from every performance. Laparoscopic novices were baseline tested and then trained on a validated virtual reality (VR) laparoscopic cholecystectomy (LC) curriculum. After competence, subjects were randomized on a 1:1 ratio and each performed 5 VRLCs. After each LC, intervention group subjects received video-based coaching by a surgeon, utilizing an adaptation of the GROW (Goals, Reality, Options, Wrap-up) coaching model. Control subjects viewed online surgical lectures. All subjects then performed 2 porcine LCs. Performance was assessed by blinded video review using validated global rating scales. Twenty subjects were recruited. No significant differences were observed between groups in baseline performance and in VRLC1. For each subsequent repetition, intervention subjects significantly outperformed controls on all global rating scales. Interventions outperformed controls in porcine LC1 [Global Operative Assessment of Laparoscopic Skills: (20.5 vs 15.5; P = 0.011), Objective Structured Assessment of Technical Skills: (21.5vs 14.5; P = 0.001), and Operative Performance Rating System: (26 vs 19.5; P = 0.001)] and porcine LC2 [Global Operative Assessment of Laparoscopic Skills: (28 vs 17.5; P = 0.005), Objective Structured Assessment of Technical Skills: (30 vs 16.5; P < 0.001), and Operative Performance Rating System: (36 vs 21; P = 0.004)]. Intervention subjects took significantly longer than controls in porcine LC1 (2920 vs 2004 seconds; P = 0.009) and LC2 (2297 vs 1683; P = 0.003). Despite equivalent exposure to practical laparoscopic skills training, video-based coaching enhanced the quality of laparoscopic surgical performance on both VR and porcine LCs, although at the expense of increased time. Video-based coaching is a feasible method of maximizing performance enhancement from every clinical exposure.

Swimming training repercussion on metabolic and structural bone development; benefits of the incorporation of whole body vibration or pilometric training; the RENACIMIENTO project.

PubMed

Gómez-Bruton, A; Gonzalez-Agüero, A; Casajus, J A; Vicente-Rodriguez, German

2014-08-01

Enviromental factors such as exercise participation and nutrition have often been linked to bone improvements. However, not all sports have the same effects, being non-osteogenic sports such as swimming defined as negative or neutral sports to practice regarding bone mass by some authors, similarly exercise-diet interaction in especific groups is still not clear. To present the methodology of the RENACIMENTO project that aims to evaluate body composition and more specifically bone mass by several techniques in adolescent swimmers and to observe the effects and perdurability of whole body vibration (WBV) and jumping intervention (JIN) on body composition and fitness on this population and explore posible diet interactions. Randomized controlled trial. 78 swimmers (12-17 y) and 26 sex- and age-matched controls will participate in this study. Dual energy X-ray, peripheral Quantitative Computed Tomography, Quantitative Ultrasound, Bioelectrical Impedance Analysis, and anthropometry measurements will be performed in order to evaluate body composition. Physical activity, nutrition, pubertal development and socio-economical status may act as confounders of body composition and therefore will also be registered. Several fitness factors regarding strength, endurance, performance and others will also be registered to evaluate differences with controls and act as confounders. A 7-month WBV therapy will be performed by 26 swimmers consisting of a training of 15 minutes 3 times per week. An 8 month JIM will also be performed by 26 swimmers 3 times per week. The remaining 26 swimmers will continue their normal swimming training. Four evaluations will be performed, the first one in order to describe differences between swimmers and controls. The second one to describe the effects of the interventions and the third and fourth evaluations to describe the perdurability of the effects of the WBV and JIN. The RENACIMIENTO project will allow to answer several questions regarding body composition, fitness, bone mass and interaction with diet of adolescent swimmers, describe swimming as a positive, negative or neutral sport to practice regarding these parameters and elucidate the effects and perdurability of WBV and JIM on body composition. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Metrology for Fuel Cell Manufacturing

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

Stocker, Michael; Stanfield, Eric

2015-02-04

The project was divided into three subprojects. The first subproject is Fuel Cell Manufacturing Variability and Its Impact on Performance. The objective was to determine if flow field channel dimensional variability has an impact on fuel cell performance. The second subproject is Non-contact Sensor Evaluation for Bipolar Plate Manufacturing Process Control and Smart Assembly of Fuel Cell Stacks. The objective was to enable cost reduction in the manufacture of fuel cell plates by providing a rapid non-contact measurement system for in-line process control. The third subproject is Optical Scatterfield Metrology for Online Catalyst Coating Inspection of PEM Soft Goods. Themore » objective was to evaluate the suitability of Optical Scatterfield Microscopy as a viable measurement tool for in situ process control of catalyst coatings.« less

An Experimental Evaluation of Stress-Management Training for the Airborne Soldier

DTIC Science & Technology

1980-06-01

skill takes considerable time and involves the learning of respiration control techniques and exercises to relax both the skeletal and smooth muscle...NUMBER 7. AUTHORia) 8. CONTRACT OR GRANT NUMBER(.) William P. Burke 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK US Army...block number) Jumpmaster training Performance under stress Stress-management training Stress reaction Respiration -control Heart rate response Deep

Exploratory investigation of high-performance fiber-reinforced cementitious composites for crack control.

DOT National Transportation Integrated Search

2008-01-01

This study evaluated high-performance fiber-reinforced cementitious composites (HPFRCC), which are mortar mixtures with synthetic and steel fibers. The feasibility of using HPFRCC technology for transportation applications by the Virginia Department ...

Comparison of virtual patient simulation with mannequin-based simulation for improving clinical performances in assessing and managing clinical deterioration: randomized controlled trial.

PubMed

Liaw, Sok Ying; Chan, Sally Wai-Chi; Chen, Fun-Gee; Hooi, Shing Chuan; Siau, Chiang

2014-09-17

Virtual patient simulation has grown substantially in health care education. A virtual patient simulation was developed as a refresher training course to reinforce nursing clinical performance in assessing and managing deteriorating patients. The objective of this study was to describe the development of the virtual patient simulation and evaluate its efficacy, by comparing with a conventional mannequin-based simulation, for improving the nursing students' performances in assessing and managing patients with clinical deterioration. A randomized controlled study was conducted with 57 third-year nursing students who were recruited through email. After a baseline evaluation of all participants' clinical performance in a simulated environment, the experimental group received a 2-hour fully automated virtual patient simulation while the control group received 2-hour facilitator-led mannequin-based simulation training. All participants were then re-tested one day (first posttest) and 2.5 months (second posttest) after the intervention. The participants from the experimental group completed a survey to evaluate their learning experiences with the newly developed virtual patient simulation. Compared to their baseline scores, both experimental and control groups demonstrated significant improvements (P<.001) in first and second post-test scores. While the experimental group had significantly lower (P<.05) second post-test scores compared with the first post-test scores, no significant difference (P=.94) was found between these two scores for the control group. The scores between groups did not differ significantly over time (P=.17). The virtual patient simulation was rated positively. A virtual patient simulation for a refreshing training course on assessing and managing clinical deterioration was developed. Although the randomized controlled study did not show that the virtual patient simulation was superior to mannequin-based simulation, both simulations have demonstrated to be effective refresher learning strategies for improving nursing students' clinical performance. Given the greater resource requirements of mannequin-based simulation, the virtual patient simulation provides a more promising alternative learning strategy to mitigate the decay of clinical performance over time.

Investigating human cognitive performance during spaceflight

NASA Astrophysics Data System (ADS)

Pattyn, Nathalie; Migeotte, Pierre-Francois; Demaeseleer, Wim; Kolinsky, Regine; Morais, Jose; Zizi, Martin

2005-08-01

Although astronauts' subjective self-evaluation of cognitive functioning often reports impairments, to date most studies of human higher cognitive functions in space never yielded univocal results. Since no golden standard exists to evaluate the higher cognitive functions, we proposed to assess astronaut's cognitive performance through a novel series of tests combined with the simultaneous recording of physiological parameters. We report here the validation of our methodology and the cognitive results of this testing on the cosmonauts from the 11 days odISSsea mission to the ISS (2002) and on a control group of pilots, carefully matched to the characteristics of the subjects. For the first time, we show a performance decrement in higher cognitive functions during space flight. Our results show a significant performance decrement for inflight measurement, as well as measurable variations in executive control of cognitive functions. Taken together, our data establish the validity of our methodology and the presence of a different information processing in operational conditions.

Age-related changes in executive control and their relationships with activity performance in handwriting.

PubMed

Rosenblum, Sara; Engel-Yeger, Batya; Fogel, Yael

2013-04-01

Deterioration in the frontal and prefrontal cortex associated with executive functions (EF) occurs with age and may be associated with changes in daily performance. The aim of the present study was to describe changes occurring with age in Executive Functions (EF) and handwriting activity, as well as to analyze relationships between age, EF and handwriting performance. The study population included 80 healthy participants (aged 31 to 76+) living in the community. After answering five questions about their writing habits, the participants completed the Behavioral Assessment of the Dysexecutive Syndrome (BADS). In addition, they performed a handwriting task on a digitizer included in the Computerized Penmanship Evaluation Tool (ComPET), which provides kinematic measures of the handwriting process. Significant differences were found between the four age groups for both EF and temporal and spatial handwriting measures. A series of regressions indicated that age predicted 35% of the variance of the BADS profile score (EF control) and 32% of the variance of in-air time while writing. The results of this study indicated age effect on both EF control and handwriting performance. Possible implications for further research and clinical evaluation and intervention are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

A course for nurses to handle difficult communication situations. A randomized controlled trial of impact on self-efficacy and performance.

PubMed

Doyle, Daniel; Copeland, H Liesel; Bush, Donna; Stein, Linda; Thompson, Scott

2011-01-01

to evaluate the impact of a communication skills course for nurses on how to handle difficult communication situations in their daily work. a 7-h course was developed using a construct of "Awareness, Feelings, Listen, Solve" (AFLS). A pedagogy of experiential, learner-centered learning was adopted. The course evaluation used a randomized controlled design with pre- and post-measures of self-efficacy and performance. forty-one nurses volunteered and thirty-three nurses completed all assigned parts of the study. On self-assessment, there was significant improvement for self-efficacy (F=24.43, p<0.001), but not for emotional awareness. On performance, there was no significant improvement between intervention and control groups (F=3.46, p=0.073). a short course for nurses on handling difficult communication situations achieved significant improvements in self-efficacy but not in performance. teaching communication skills in community-based settings is important for the safety and effectiveness of patient care. Sponsoring organizations should weigh trade-offs between feasibility and achievement of measurable improvements in performance. One possible approach is to focus on specific communication skills rather than a full suite of skills. 2010 Elsevier Ireland Ltd. All rights reserved.

EVALUATION OF ENGINEERING CONTROLS FOR THE MIXING OF FLAVORINGS CONTAINING DIACETYL AND OTHER VOLATILE INGREDIENTS

PubMed Central

Hirst, Deborah V.L.; Dunn, Kevin H.; Shulman, Stanley A.; Hammond, Duane R.; Sestito, Nicholas

2015-01-01

Exposures to diacetyl, a primary ingredient of butter flavoring, have been shown to cause respiratory disease among workers who mix flavorings. This study focused on evaluating ventilation controls designed to reduce emissions from the flavor mixing tanks, the major source of diacetyl in the plants. Five exhaust hood configurations were evaluated in the laboratory: standard hinged lid-opened, standard hinged lid-closed, hinged lid-slotted, dome with 38-mm gap, and dome with 114-mm gap. Tracer gas tests were performed to evaluate quantitative capture efficiency for each hood. A perforated copper coil was used to simulate an area source within the 1.2-meter diameter mixing tank. Capture efficiencies were measured at four hood exhaust flow rates (2.83, 5.66, 11.3, and 17.0 cubic meters per minute) and three cross draft velocities (0, 30, and 60 meters per minute). All hoods evaluated performed well with capture efficiencies above 90% for most combinations of exhaust volume and cross drafts. The standard hinged lid was the least expensive to manufacture and had the best average capture efficiency (over 99%) in the closed configuration for all exhaust flow rates and cross drafts. The hinged lid-slotted hood had some of the lowest capture efficiencies at the low exhaust flow rates compared to the other hood designs. The standard hinged lid performed well, even in the open position, and it provided a flexible approach to controlling emissions from mixing tanks. The dome hood gave results comparable to the standard hinged lid but it is more expensive to manufacture. The results of the study indicate that emissions from mixing tanks used in the production of flavorings can be controlled using simple inexpensive exhaust hoods. PMID:24649880

PrismTech Data Distribution Service Java API Evaluation

NASA Technical Reports Server (NTRS)

Riggs, Cortney

2008-01-01

My internship duties with Launch Control Systems required me to start performance testing of an Object Management Group's (OMG) Data Distribution Service (DDS) specification implementation by PrismTech Limited through the Java programming language application programming interface (API). DDS is a networking middleware for Real-Time Data Distribution. The performance testing involves latency, redundant publishers, extended duration, redundant failover, and read performance. Time constraints allowed only for a data throughput test. I have designed the testing applications to perform all performance tests when time is allowed. Performance evaluation data such as megabits per second and central processing unit (CPU) time consumption were not easily attainable through the Java programming language; they required new methods and classes created in the test applications. Evaluation of this product showed the rate that data can be sent across the network. Performance rates are better on Linux platforms than AIX and Sun platforms. Compared to previous C++ programming language API, the performance evaluation also shows the language differences for the implementation. The Java API of the DDS has a lower throughput performance than the C++ API.

Performance Evaluation of an Automotive-Grade, High Speed Gate Driver for SiC FETs, Type UCC27531, Over a Wide Temperature Range

NASA Technical Reports Server (NTRS)

Boomer, Kristen; Hammoud, Ahmad

2015-01-01

Silicon carbide (SiC) devices are becoming widely used in electronic power circuits as replacement for conventional silicon parts due to their attractive properties that include low on-state resistance, high temperature tolerance, and high frequency operation. These attributes have a significant impact by reducing system weight, saving board space, and conserving power. In this work, the performance of an automotive-grade high speed gate driver with potential use in controlling SiC FETs (field-Effect Transistors) in converters or motor control applications was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to assess performance and to determine suitability of this device for use in space exploration missions under extreme temperature conditions.

Extended performance electric propulsion power processor design study. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.

1977-01-01

Several power processor design concepts were evaluated and compared. Emphasis was placed on a 30cm ion thruster power processor with a beam supply rating of 2.2kW to 10kW. Extensions in power processor performance were defined and were designed in sufficient detail to determine efficiency, component weight, part count, reliability and thermal control. Preliminary electrical design, mechanical design, and thermal analysis were performed on a 6kW power transformer for the beam supply. Bi-Mod mechanical, structural, and thermal control configurations were evaluated for the power processor, and preliminary estimates of mechanical weight were determined. A program development plan was formulated that outlines the work breakdown structure for the development, qualification and fabrication of the power processor flight hardware.

LSS systems planning and performance program

NASA Technical Reports Server (NTRS)

Mckenna, Victoria Jones; Dendy, Michael J.; Naumann, Charles B.; Rice, Sally A.; Weathers, John M.

1993-01-01

This report describes, using viewgraphs, the Marshall Space Flight Center's Large Space Structures Ground Test Facilities located in building 4619. Major topics include the Active Control Evaluation of Systems (ACES) Laboratory; the Control-Structures Interaction/Controls, Astrophysics, and Structures Experiment in Space (CSI/CASES); Advanced Development Facility; and the ACES Guest Investigator Program.

Intelligent control of a smart walker and its performance evaluation.

PubMed

Grondin, Simon L; Li, Qingguo

2013-06-01

Recent technological advances have allowed the development of force-dependent, intelligently controlled smart walkers that are able to provide users with enhanced mobility, support and gait assistance. The purpose of this study was to develop an intelligent rule-based controller for a smart walker to achieve a smooth interaction between the user and the walker. This study developed a rule-based mapping between the interaction force, measured by a load cell attached to the walker handle, and the acceleration of the walker. Ten young, healthy subjects were used to evaluate the performance of the proposed controller compared to a well-known admittance-based control system. There were no significant differences between the two control systems concerning their user experience, velocity profiles or average cost of transportation. However, the admittance-based control system required a 1.2N lower average interaction force to maintain the 1m/s target speed (p = 0.002). Metabolic data also indicated that smart walker-assisted gait could considerably reduce the metabolic demand of walking with a four-legged walker.

Controlling robots in the home: Factors that affect the performance of novice robot operators.

PubMed

McGinn, Conor; Sena, Aran; Kelly, Kevin

2017-11-01

For robots to successfully integrate into everyday life, it is important that they can be effectively controlled by laypeople. However, the task of manually controlling mobile robots can be challenging due to demanding cognitive and sensorimotor requirements. This research explores the effect that the built environment has on the manual control of domestic service robots. In this study, a virtual reality simulation of a domestic robot control scenario was developed. The performance of fifty novice users was evaluated, and their subjective experiences recorded through questionnaires. Through quantitative and qualitative analysis, it was found that untrained operators frequently perform poorly at navigation-based robot control tasks. The study found that passing through doorways accounted for the largest number of collisions, and was consistently identified as a very difficult operation to perform. These findings suggest that homes and other human-orientated settings present significant challenges to robot control. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intelligent Life-Extending Controls for Aircraft Engines

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei; Chen, Philip; Jaw, Link

2005-01-01

Aircraft engine controllers are designed and operated to provide desired performance and stability margins. The purpose of life-extending-control (LEC) is to study the relationship between control action and engine component life usage, and to design an intelligent control algorithm to provide proper trade-offs between performance and engine life usage. The benefit of this approach is that it is expected to maintain safety while minimizing the overall operating costs. With the advances of computer technology, engine operation models, and damage physics, it is necessary to reevaluate the control strategy fro overall operating cost consideration. This paper uses the thermo-mechanical fatigue (TMF) of a critical component to demonstrate how an intelligent engine control algorithm can drastically reduce the engine life usage with minimum sacrifice in performance. A Monte Carlo simulation is also performed to evaluate the likely engine damage accumulation under various operating conditions. The simulation results show that an optimized acceleration schedule can provide a significant life saving in selected engine components.

Tracking control of concentration profiles in a fed-batch bioreactor using a linear algebra methodology.

PubMed

Rómoli, Santiago; Serrano, Mario Emanuel; Ortiz, Oscar Alberto; Vega, Jorge Rubén; Eduardo Scaglia, Gustavo Juan

2015-07-01

Based on a linear algebra approach, this paper aims at developing a novel control law able to track reference profiles that were previously-determined in the literature. A main advantage of the proposed strategy is that the control actions are obtained by solving a system of linear equations. The optimal controller parameters are selected through Monte Carlo Randomized Algorithm in order to minimize a proposed cost index. The controller performance is evaluated through several tests, and compared with other controller reported in the literature. Finally, a Monte Carlo Randomized Algorithm is conducted to assess the performance of the proposed controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Vestibular models for design and evaluation of flight simulator motion

NASA Technical Reports Server (NTRS)

Bussolari, S. R.; Sullivan, R. B.; Young, L. R.

1986-01-01

The use of spatial orientation models in the design and evaluation of control systems for motion-base flight simulators is investigated experimentally. The development of a high-fidelity motion drive controller using an optimal control approach based on human vestibular models is described. The formulation and implementation of the optimal washout system are discussed. The effectiveness of the motion washout system was evaluated by studying the response of six motion washout systems to the NASA/AMES Vertical Motion Simulator for a single dash-quick-stop maneuver. The effects of the motion washout system on pilot performance and simulator acceptability are examined. The data reveal that human spatial orientation models are useful for the design and evaluation of flight simulator motion fidelity.

Thermal performance of MSFC hot air collectors under natural and simulated conditions

NASA Technical Reports Server (NTRS)

Shih, K., Sr.

1977-01-01

The procedures used and the results obtained from an evaluation test program conducted to determine the thermal performance and structural characteristics of selected MSFC--designed hot air collectors under both real and simulated environmental conditions are described. Five collectors were tested in the three phased program. A series of outdoor tests were conducted to determine stagnation temperatures on a typical bright day and to determine each collector's ability to withstand these temperatures. Two of the collectors experienced structural deformation sufficient to eliminate them from the remainder of the test program. A series of outdoor tests to evaluate the thermal performance of collector S/N 10 under certain test conditions were performed followed by a series of indoor tests to evaluate the thermal performance of the collector under closely controlled simulated conditions.

FLUORESCENT TRACER EVALUATION OF PROTECTIVE CLOTHING PERFORMANCE

EPA Science Inventory

Field studies evaluating chemical protective clothing (CPC), which is often employed as a primary control option to reduce occupational exposures during pesticide applications, are limited. This study, supported by the U.S. Environmental Protection Agency (EPA), was designed to...

Evaluation of narrow transverse contraction joints in jointed plain concrete pavements.

DOT National Transportation Integrated Search

2006-03-01

This report presents the results of a research project conducted at the Louisiana Transportation Research Center (LTRC) to evaluate the performance of narrow transverse contraction joints to control cracking in jointed plain concrete pavements. In ad...

EVALUATION OF FOUR NOVEL FINE PARTICULATE COLLECTION DEVICES

EPA Science Inventory

The report gives results of an experimental performance evaluation of four novel fine particulate control devices: the Johns-Manville Cleanable High-Efficiency Air Filtration (CHEAF) System, the APS Electrostatic Scrubber, the APS Electrotube, and the TRW Charged Droplet Scrubber...

Modeling and control of non-square MIMO system using relay feedback.

PubMed

Kalpana, D; Thyagarajan, T; Gokulraj, N

2015-11-01

This paper proposes a systematic approach for the modeling and control of non-square MIMO systems in time domain using relay feedback. Conventionally, modeling, selection of the control configuration and controller design of non-square MIMO systems are performed using input/output information of direct loop, while the output of undesired responses that bears valuable information on interaction among the loops are not considered. However, in this paper, the undesired response obtained from relay feedback test is also taken into consideration to extract the information about the interaction between the loops. The studies are performed on an Air Path Scheme of Turbocharged Diesel Engine (APSTDE) model, which is a typical non-square MIMO system, with input and output variables being 3 and 2 respectively. From the relay test response, the generalized analytical expressions are derived and these analytical expressions are used to estimate unknown system parameters and also to evaluate interaction measures. The interaction is analyzed by using Block Relative Gain (BRG) method. The model thus identified is later used to design appropriate controller to carry out closed loop studies. Closed loop simulation studies were performed for both servo and regulatory operations. Integral of Squared Error (ISE) performance criterion is employed to quantitatively evaluate performance of the proposed scheme. The usefulness of the proposed method is demonstrated on a lab-scale Two-Tank Cylindrical Interacting System (TTCIS), which is configured as a non-square system. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Summary of electric vehicle dc motor-controller tests

NASA Technical Reports Server (NTRS)

Mcbrien, E. F.; Tryon, H. B.

1982-01-01

The differences in the performance of dc motors are evaluated when operating with chopper type controllers, and when operating on direct current. The interactions between the motor and the controller which cause these differences are investigated. Motor-controlled tests provided some of the data the quantified motor efficiency variations for both ripple free and chopper modes of operation.

Evaluation of induction motor performance using an electronic power factor controller

NASA Technical Reports Server (NTRS)

1978-01-01

The concept of reducing the losses in an induction motor by electronically controlling the time interval between the zero crossing of the applied voltage and the zero crossing of the armature current was evaluated. The effect on power losses and power factor of reducing the applied sinusoidal voltages below the rated value was investigated experimentally. The reduction in power losses was measured using an electronic controller designed and built at MSFC. Modifications to the MSFC controller are described as well as a manually controlled electronic device which does not require that the motor be wye connected and the neutral available. Possible energy savings are examined.

Large-scale performance evaluation of Accu-Chek inform II point-of-care glucose meters.

PubMed

Jeong, Tae-Dong; Cho, Eun-Jung; Ko, Dae-Hyun; Lee, Woochang; Chun, Sail; Hong, Ki-Sook; Min, Won-Ki

2016-12-01

The aim of this study was to report the experience of large-scale performance evaluation of 238 Accu-Chek Inform II point-of-care (POC) glucose meters in a single medical setting. The repeatability of 238 POC devices, the within-site imprecision of 12 devices, and the linearity of 49 devices were evaluated using glucose control solutions. The glucose results of 24 POC devices and central laboratory were compared using patient samples. Mean concentration of control solutions was 2.39 mmol/L for Level 1 and 16.52 mmol/L for Level 2. The pooled repeatability coefficient of variation (CV) of the 238 devices was 2.0% for Level 1 and 1.6% for Level 2. The pooled within-site imprecision CV and reproducibility CV of the 12 devices were 2.7% and 2.7% for Level 1, and 1.9%, and 1.9% for Level 2, respectively. The test results of all 49 devices were linear within analytical measurement range from 1.55-31.02 mmol/L. The correlation coefficient for individual POC devices ranged from 0.9967-0.9985. The total correlation coefficient for the 24 devices was 0.998. The Accu-Chek Inform II POC blood glucose meters performed well in terms of precision, linearity, and correlation evaluations. Consensus guidelines for the large-scale performance evaluations of POC devices are required.

Manual and automatic flight control during severe turbulence penetration

NASA Technical Reports Server (NTRS)

Johnston, D. E.; Klein, R. H.; Hoh, R. H.

1976-01-01

An analytical and experimental investigation of possible contributing factors in jet aircraft turbulence upsets was conducted. Major contributing factors identified included autopilot and display deficiencies, the large aircraft inertia and associated long response time, and excessive pilot workload. An integrated flight and thrust energy management director system was synthesized. The system was incorporated in a moving-base simulation and evaluated using highly experienced airline pilots. The evaluation included comparison of pilot workload and flight performance during severe turbulence penetration utilizing four control/display concepts: manual control with conventional full panel display, conventional autopilot (A/P-A) with conventional full panel display, improved autopilot (A/P-B) with conventional full panel display plus thrust director display, and longitudinal flight director with conventional full panel display plus thrust director display. Simulation results show improved performance, reduced pilot workload, and a pilot preference for the autopilot system controlling to the flight director command and manual control of thrust following the trim thrust director.

Mindfulness Meditation Improves Mood, Quality of Life, and Attention in Adults with Attention Deficit Hyperactivity Disorder

PubMed Central

2015-01-01

Objective. Adults with attention deficit hyperactivity disorder (ADHD) display affective problems and impaired attention. Mood in ADHD can be improved by mindful awareness practices (MAP), but results are mixed regarding the enhancement of attentional performance. Here we evaluated MAP-induced changes in quality of life (QoL), mood, and attention in adult ADHD patients and controls using more measures of attention than prior studies. Methods. Twenty-one ADHD patients and 8 healthy controls underwent 8 weekly MAP sessions; 22 similar patients and 9 controls did not undergo the intervention. Mood and QoL were assessed using validated questionnaires, and attention was evaluated using the Attentional Network Test (ANT) and the Conners Continuous Performance Test (CPT II), before and after intervention. Results. MAP enhanced sustained attention (ANT) and detectability (CPT II) and improved mood and QoL of patients and controls. Conclusion. MAP is a complementary intervention that improves affect and attention of adults with ADHD and controls. PMID:26137496

Mindfulness Meditation Improves Mood, Quality of Life, and Attention in Adults with Attention Deficit Hyperactivity Disorder.

PubMed

Bueno, Viviane Freire; Kozasa, Elisa H; da Silva, Maria Aparecida; Alves, Tânia Maria; Louzã, Mario Rodrigues; Pompéia, Sabine

2015-01-01

Adults with attention deficit hyperactivity disorder (ADHD) display affective problems and impaired attention. Mood in ADHD can be improved by mindful awareness practices (MAP), but results are mixed regarding the enhancement of attentional performance. Here we evaluated MAP-induced changes in quality of life (QoL), mood, and attention in adult ADHD patients and controls using more measures of attention than prior studies. Twenty-one ADHD patients and 8 healthy controls underwent 8 weekly MAP sessions; 22 similar patients and 9 controls did not undergo the intervention. Mood and QoL were assessed using validated questionnaires, and attention was evaluated using the Attentional Network Test (ANT) and the Conners Continuous Performance Test (CPT II), before and after intervention. MAP enhanced sustained attention (ANT) and detectability (CPT II) and improved mood and QoL of patients and controls. MAP is a complementary intervention that improves affect and attention of adults with ADHD and controls.

Neural networks as a control methodology

NASA Technical Reports Server (NTRS)

Mccullough, Claire L.

1990-01-01

While conventional computers must be programmed in a logical fashion by a person who thoroughly understands the task to be performed, the motivation behind neural networks is to develop machines which can train themselves to perform tasks, using available information about desired system behavior and learning from experience. There are three goals of this fellowship program: (1) to evaluate various neural net methods and generate computer software to implement those deemed most promising on a personal computer equipped with Matlab; (2) to evaluate methods currently in the professional literature for system control using neural nets to choose those most applicable to control of flexible structures; and (3) to apply the control strategies chosen in (2) to a computer simulation of a test article, the Control Structures Interaction Suitcase Demonstrator, which is a portable system consisting of a small flexible beam driven by a torque motor and mounted on springs tuned to the first flexible mode of the beam. Results of each are discussed.

ATAD control goals through the analysis of process variables and evaluation of quality, production and cost.

PubMed

Nájera, S; Gil-Martínez, M; Zambrano, J A

2015-01-01

The aim of this paper is to establish and quantify different operational goals and control strategies in autothermal thermophilic aerobic digestion (ATAD). This technology appears as an alternative to conventional sludge digestion systems. During the batch-mode reaction, high temperatures promote sludge stabilization and pasteurization. The digester temperature is usually the only online, robust, measurable variable. The average temperature can be regulated by manipulating both the air injection and the sludge retention time. An improved performance of diverse biochemical variables can be achieved through proper manipulation of these inputs. However, a better quality of treated sludge usually implies major operating costs or a lower production rate. Thus, quality, production and cost indices are defined to quantify the outcomes of the treatment. Based on these, tradeoff control strategies are proposed and illustrated through some examples. This paper's results are relevant to guide plant operators, to design automatic control systems and to compare or evaluate the control performance on ATAD systems.

Effects of modified constraint-induced movement therapy on reach-to-grasp movements and functional performance after chronic stroke: a randomized controlled study.

PubMed

Lin, K-C; Wu, C-Y; Wei, T-H; Lee, C-Y; Liu, J-S

2007-12-01

To evaluate changes in (1) motor control characteristics of the hemiparetic hand during the performance of a functional reach-to-grasp task and (2) functional performance of daily activities in patients with stroke treated with modified constraint-induced movement therapy. Two-group randomized controlled trial with pretreatment and posttreatment measures. Rehabilitation clinics. Thirty-two chronic stroke patients (21 men, 11 women; mean age=57.9 years, range=43-81 years) 13-26 months (mean 16.3 months) after onset of a first-ever cerebrovascular accident. Thirty-two patients were randomized to receive modified constraint-induced movement therapy (restraint of the unaffected limb combined with intensive training of the affected limb) or traditional rehabilitation for three weeks. Kinematic analysis was used to assess motor control characteristics as patients reached to grasp a beverage can. Functional outcomes were evaluated using the Motor Activity Log and Functional Independence Measure. There were moderate and significant effects of modified constraint-induced movement therapy on some aspects of motor control of reach-to-grasp and on functional ability. The modified constraint-induced movement therapy group preplanned reaching and grasping (P=0.018) more efficiently and depended more on the feedforward control of reaching (P=0.046) than did the traditional rehabilitation group. The modified constraint-induced movement therapy group also showed significantly improved functional performance on the Motor Activity Log (P<0.0001) and the Functional Independence Measure (P=0.016). In addition to improving functional use of the affected arm and daily functioning, modified constraint-induced movement therapy improved motor control strategy during goal-directed reaching, a possible mechanism for the improved movement performance of stroke patients undergoing this therapy.

Terrain interaction with the quarter scale beam walker

NASA Technical Reports Server (NTRS)

Chun, Wendell H.; Price, S.; Spiessbach, A.

1990-01-01

Frame walkers are a class of mobile robots that are robust and capable mobility platforms. Variations of the frame walker robot are in commercial use today. Komatsu Ltd. of Japan developed the Remotely Controlled Underwater Surveyor (ReCUS) and Normed Shipyards of France developed the Marine Robot (RM3). Both applications of the frame walker concept satisfied robotic mobility requirements that could not be met by a wheeled or tracked design. One vehicle design concept that falls within this class of mobile robots is the walking beam. A one-quarter scale prototype of the walking beam was built by Martin Marietta to evaluate the potential merits of utilizing the vehicle as a planetary rover. The initial phase of prototype rover testing was structured to evaluate the mobility performance aspects of the vehicle. Performance parameters such as vehicle power, speed, and attitude control were evaluated as a function of the environment in which the prototype vehicle was tested. Subsequent testing phases will address the integrated performance of the vehicle and a local navigation system.

Terrain Interaction With The Quarter Scale Beam Walker

NASA Astrophysics Data System (ADS)

Chun, Wendell H.; Price, R. S.; Spiessbach, Andrew J.

1990-03-01

Frame walkers are a class of mobile robots that are robust and capable mobility platforms. Variations of the frame walker robot are in commercial use today. Komatsu Ltd. of Japan developed the Remotely Controlled Underwater Surveyor (ReCUS) and Normed Shipyards of France developed the Marine Robot (RM3). Both applications of the frame walker concept satisfied robotic mobility requirements that could not be met by a wheeled or tracked design. One vehicle design concept that falls within this class of mobile robots is the walking beam. A one-quarter scale prototype of the walking beam was built by Martin Marietta to evaluate the potential merits of utilizing the vehicle as a planetary rover. The initial phase of prototype rover testing was structured to evaluate the mobility performance aspects of the vehicle. Performance parameters such as vehicle power, speed, and attitude control were evaluated as a function of the environment in which the prototype vehicle was tested. Subsequent testing phases will address the integrated performance of the vehicle and a local navigation system.

Combustion performance and heat transfer characterization of LOX/hydrocarbon type propellants

NASA Technical Reports Server (NTRS)

Michel, R. W.

1983-01-01

An evaluation liquid oxygen (LOX) and various hydrocarbon fuels as low cost alternative propellants suitable for future space transportation system applications was done. The emphasis was directed toward low earth orbit maneuvering engine and reaction control engine systems. The feasibility of regeneratively cooling an orbit maneuvering thruster was analytically determined over a range of operating conditions from 100 to 1000 psia chamber pressure and 1000 to 10,000-1bF thrust, and specific design points were analyzed in detail for propane, methane, RP-1, ammonia, and ethanol; similar design point studies were performed for a film-cooled reaction control thruster. Heat transfer characteristics of propane were experimentally evaluated in heated tube tests. Forced convection heat transfer coefficients were determined. Seventy-seven hot firing tests were conducted with LOX/propane and LOX/ethanol, for a total duration of nearly 1400 seconds, using both heat sink and water-cooled calorimetric chambers. Combustion performance and stability and gas-side heat transfer characteristics were evaluated.

A state-trajectory control law for dc-to-dc converters

NASA Technical Reports Server (NTRS)

Burns, W. W., III; Wilson, T. G.

1978-01-01

Mathematical representations of a state-plane switching boundary employed in a state-trajectory control law for dc-to-dc converters are derived. Several levels of approximation to the switching boundary equations are presented, together with an evaluation of the effects of nonideal operating characteristics of converter power stage components on the shape and location of the boundary and the behavior of a system controlled by it. Digital computer simulations of dc-to-dc converters operating in conjunction with each of these levels of control are presented and evaluated with respect to changes in transient and steady-state performance.

A high performing brain-machine interface driven by low-frequency local field potentials alone and together with spikes

NASA Astrophysics Data System (ADS)

Stavisky, Sergey D.; Kao, Jonathan C.; Nuyujukian, Paul; Ryu, Stephen I.; Shenoy, Krishna V.

2015-06-01

Objective. Brain-machine interfaces (BMIs) seek to enable people with movement disabilities to directly control prosthetic systems with their neural activity. Current high performance BMIs are driven by action potentials (spikes), but access to this signal often diminishes as sensors degrade over time. Decoding local field potentials (LFPs) as an alternative or complementary BMI control signal may improve performance when there is a paucity of spike signals. To date only a small handful of LFP decoding methods have been tested online; there remains a need to test different LFP decoding approaches and improve LFP-driven performance. There has also not been a reported demonstration of a hybrid BMI that decodes kinematics from both LFP and spikes. Here we first evaluate a BMI driven by the local motor potential (LMP), a low-pass filtered time-domain LFP amplitude feature. We then combine decoding of both LMP and spikes to implement a hybrid BMI. Approach. Spikes and LFP were recorded from two macaques implanted with multielectrode arrays in primary and premotor cortex while they performed a reaching task. We then evaluated closed-loop BMI control using biomimetic decoders driven by LMP, spikes, or both signals together. Main results. LMP decoding enabled quick and accurate cursor control which surpassed previously reported LFP BMI performance. Hybrid decoding of both spikes and LMP improved performance when spikes signal quality was mediocre to poor. Significance. These findings show that LMP is an effective BMI control signal which requires minimal power to extract and can substitute for or augment impoverished spikes signals. Use of this signal may lengthen the useful lifespan of BMIs and is therefore an important step towards clinically viable BMIs.

The Effectiveness of Permanent Highway Runoff Controls: Sedimentation/Filtration Systems

DOT National Transportation Integrated Search

1998-09-01

Original Report Date: October 1997. This study evaluates the performance of sedimentation/filtration systems that are the most common control for treating highway runoff in the Edwards Aquifer recharge zone. The study includes: 1) monitoring and eval...

Global chemical profiling based quality evaluation approach of rhubarb using ultra performance liquid chromatography with tandem quadrupole time-of-flight mass spectrometry.

PubMed

Zhang, Li; Liu, Haiyu; Qin, Lingling; Zhang, Zhixin; Wang, Qing; Zhang, Qingqing; Lu, Zhiwei; Wei, Shengli; Gao, Xiaoyan; Tu, Pengfei

2015-02-01

A global chemical profiling based quality evaluation approach using ultra performance liquid chromatography with tandem quadrupole time-of-flight mass spectrometry was developed for the quality evaluation of three rhubarb species, including Rheum palmatum L., Rheum tanguticum Maxim. ex Balf., and Rheum officinale Baill. Considering that comprehensive detection of chemical components is crucial for the global profile, a systemic column performance evaluation method was developed. Based on this, a Cortecs column was used to acquire the chemical profile, and Chempattern software was employed to conduct similarity evaluation and hierarchical cluster analysis. The results showed R. tanguticum could be differentiated from R. palmatum and R. officinale at the similarity value 0.65, but R. palmatum and R. officinale could not be distinguished effectively. Therefore, a common pattern based on three rhubarb species was developed to conduct the quality evaluation, and the similarity value 0.50 was set as an appropriate threshold to control the quality of rhubarb. A total of 88 common peaks were identified by their accurate mass and fragmentation, and partially verified by reference standards. Through the verification, the newly developed method could be successfully used for evaluating the holistic quality of rhubarb. It would provide a reference for the quality control of other herbal medicines. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

LANDSAT-4 MSS Geometric Correction: Methods and Results

NASA Technical Reports Server (NTRS)

Brooks, J.; Kimmer, E.; Su, J.

1984-01-01

An automated image registration system such as that developed for LANDSAT-4 can produce all of the information needed to verify and calibrate the software and to evaluate system performance. The on-line MSS archive generation process which upgrades systematic correction data to geodetic correction data is described as well as the control point library build subsystem which generates control point chips and support data for on-line upgrade of correction data. The system performance was evaluated for both temporal and geodetic registration. For temporal registration, 90% errors were computed to be .36 IFOV (instantaneous field of view) = 82.7 meters) cross track, and .29 IFOV along track. Also, for actual production runs monitored, the 90% errors were .29 IFOV cross track and .25 IFOV along track. The system specification is .3 IFOV, 90% of the time, both cross and along track. For geodetic registration performance, the model bias was measured by designating control points in the geodetically corrected imagery.

Performance of ZnO based piezo-generators under controlled compression

NASA Astrophysics Data System (ADS)

Tao, Ran; Parmar, Mitesh; Ardila, Gustavo; Oliveira, Paulo; Marques, Daniel; Montès, Laurent; Mouis, Mireille

2017-06-01

This paper reports on the fabrication and characterization of ZnO based vertically integrated nanogenerator (VING) devices under controlled compression. The basic NG structure is a composite material integrating hydrothermally grown vertical piezoelectric zinc oxide (ZnO) nanowires (NWs) into a dielectric matrix (PMMA). A specific characterization set-up has been developed to control the applied compression and the perpendicularity of the applied force on the devices. The role of different fabrication parameters has been evaluated experimentally and compared with previously reported theoretical models, including the thickness of the top PMMA layer and the density of the NWs array in the matrix. Finally, the performance of the VING structure has been evaluated experimentally for different resistive loads obtaining a power density of 85 μW cm-3 considering only the active layer of the device. This has been compared to the performance of a commercial bulk layer of PZT (25 μW cm-3) under the same applied force of 5 N.

Comparative study of popular objective functions for damping power system oscillations in multimachine system.

PubMed

Islam, Naz Niamul; Hannan, M A; Shareef, Hussain; Mohamed, Azah; Salam, M A

2014-01-01

Power oscillation damping controller is designed in linearized model with heuristic optimization techniques. Selection of the objective function is very crucial for damping controller design by optimization algorithms. In this research, comparative analysis has been carried out to evaluate the effectiveness of popular objective functions used in power system oscillation damping. Two-stage lead-lag damping controller by means of power system stabilizers is optimized using differential search algorithm for different objective functions. Linearized model simulations are performed to compare the dominant mode's performance and then the nonlinear model is continued to evaluate the damping performance over power system oscillations. All the simulations are conducted in two-area four-machine power system to bring a detailed analysis. Investigated results proved that multiobjective D-shaped function is an effective objective function in terms of moving unstable and lightly damped electromechanical modes into stable region. Thus, D-shape function ultimately improves overall system damping and concurrently enhances power system reliability.

Effect of vaginal spheres and pelvic floor muscle training in women with urinary incontinence: a randomized, controlled trial.

PubMed

Porta-Roda, Oriol; Vara-Paniagua, Jesús; Díaz-López, Miguel A; Sobrado-Lozano, Pilar; Simó-González, Marta; Díaz-Bellido, Paloma; Reula-Blasco, María C; Muñoz-Garrido, Francisco

2015-08-01

To compare the efficacy and safety of Kegel exercises performed with or without, vaginal spheres as treatment for women with urinary incontinence. Multicentre parallel-group, open, randomized controlled trial. Women were allocated to either a pelvic floor muscle-training program consisting of Kegel exercises performed twice daily, 5 days/week at home, over 6 months with vaginal spheres, or to the same program without spheres. The primary endpoint was women's report of urinary incontinence at 6 months using the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI-SF). Secondary outcome measures were the 1 hr pad-test, King's Health Questionnaire (KHQ) and a five-point Likert scale for subjective evaluation. Adherence was measured with the Morisky-Green test. Thirty-seven women were randomized to the spheres group and 33 to the control group. The primary endpoint was evaluated in 65 women (35 in the spheres group vs. 30 controls). ICIQ-UI-SF results improved significantly at 1-month follow-up in the spheres group (P < 0.01) and at 6 months in the controls. The 1 hr pad-test improved in the spheres group but not in the control group. No significant differences were found in the KHQ results or in the subjective evaluation of efficacy and safety. Adherence was higher in the spheres group but differences were not significant. Mild transient side effects were reported in four patients in the spheres group and one in the control group. Both treatments improved urinary incontinence but women who performed the exercises with vaginal spheres showed an earlier improvement. Vaginal spheres were well tolerated and safe. © 2014 Wiley Periodicals, Inc.

Novel surgical performance evaluation approximates Standardized Incidence Ratio with high accuracy at simple means.

PubMed

Gabbay, Itay E; Gabbay, Uri

2013-01-01

Excess adverse events may be attributable to poor surgical performance but also to case-mix, which is controlled through the Standardized Incidence Ratio (SIR). SIR calculations can be complicated, resource consuming, and unfeasible in some settings. This article suggests a novel method for SIR approximation. In order to evaluate a potential SIR surrogate measure we predefined acceptance criteria. We developed a new measure - Approximate Risk Index (ARI). "Number Needed for Event" (NNE) is the theoretical number of patients needed "to produce" one adverse event. ARI is defined as the quotient of the group of patients needed for no observed events Ge by total patients treated Ga. Our evaluation compared 2500 surgical units and over 3 million heterogeneous risk surgical patients that were induced through a computerized simulation. Surgical unit's data were computed for SIR and ARI to evaluate compliance with the predefined criteria. Approximation was evaluated by correlation analysis and performance prediction capability by Receiver Operating Characteristics (ROC) analysis. ARI strongly correlates with SIR (r(2) = 0.87, p < 0.05). ARI prediction of excessive risk revealed excellent ROC (Area Under the Curve > 0.9) 87% sensitivity and 91% specificity. ARI provides good approximation of SIR and excellent prediction capability. ARI is simple and cost-effective as it requires thorough risk evaluation of only the adverse events patients. ARI can provide a crucial screening and performance evaluation quality control tool. The ARI method may suit other clinical and epidemiological settings where relatively small fraction of the entire population is affected. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Performance of Particulate Containment at Nanotechnology Workplaces

PubMed Central

Lo, Li-Ming; Tsai, Candace S.-J.; Dunn, Kevin H.; Hammond, Duane; Marlow, David; Topmiller, Jennifer; Ellenbecker, Michael

2015-01-01

The evaluation of engineering controls for the production or use of carbon nanotubes (CNTs) was investigated at two facilities. These controls assessments are necessary to evaluate the current status of control performance and to develop proper control strategies for these workplaces. The control systems evaluated in these studies included ventilated enclosures, exterior hoods, and exhaust filtration systems. Activity-based monitoring with direct-reading instruments and filter sampling for microscopy analysis were used to evaluate the effectiveness of control measures at study sites. Our study results showed that weighing CNTs inside the biological safety cabinet can have a 37% reduction on the particle concentration in the worker’s breathing zone, and produce a 42% lower area concentration outside the enclosure. The ventilated enclosures used to reduce fugitive emissions from the production furnaces exhibited good containment characteristics when closed, but they failed to contain emissions effectively when opened during product removal/harvesting. The exhaust filtration systems employed for exhausting these ventilated enclosures did not provide promised collection efficiencies for removing engineered nanomaterials from furnace exhaust. The exterior hoods were found to be a challenge for controlling emissions from machining nanocomposites: the downdraft hood effectively contained and removed particles released from the manual cutting process, but using the canopy hood for powered cutting of nanocomposites created 15%–20% higher ultrafine (<500 nm) particle concentrations at the source and at the worker’s breathing zone. The microscopy analysis showed that CNTs can only be found at production sources but not at the worker breathing zones during the tasks monitored. PMID:26705393

Knowledge-Acquisition Tool For Expert System

NASA Technical Reports Server (NTRS)

Disbrow, James D.; Duke, Eugene L.; Regenie, Victoria A.

1988-01-01

Digital flight-control systems monitored by computer program that evaluates and recommends. Flight-systems engineers for advanced, high-performance aircraft use knowlege-acquisition tool for expert-system flight-status monitor suppling interpretative data. Interpretative function especially important in time-critical, high-stress situations because it facilitates problem identification and corrective strategy. Conditions evaluated and recommendations made by ground-based engineers having essential knowledge for analysis and monitoring of performances of advanced aircraft systems.

Precision Stellar Catalogs and the Role of Anomalous Refraction.

DTIC Science & Technology

1978-01-01

program to evaluate the use of Two Color Refractometry (TCR) for the determination of precise stel- lar positions is discussed. Various aspects of...Display Control Console Most of the electronic subsystems which are required to perform the various functions for the Two Color Refractometry are...development of the Two-Color Refractometry System. To this end, we are performing Two-Color Refractometry evaluations on components similar to those to be

Open friction courses on an asphaltic concrete base: A seven-year progress report

NASA Astrophysics Data System (ADS)

Dodge, K. S.

1982-10-01

The performance of two open-friction courses (OFC) having 1/2 in. and 1/4 in. maximum-sized aggregates - and their adjacent conventional New York State 1A top-course (control) is documented over the final 4 years of their 7-year design lives. The pavements were evaluated by analysis of mix properties and surface performance. The physical properties examined by means of extracted pavement cores were aggregate gradation, binder penetration and viscosities, and void content. Testing of frictional performance, rut depths, microtecture and macrotexture, rideability, and cracking were used to evaluate the pavement's surface performance.

Home-based, early intervention with mechatronic toys for preterm infants at risk of neurodevelopmental disorders (CARETOY): a RCT protocol.

PubMed

Sgandurra, Giuseppina; Bartalena, Laura; Cioni, Giovanni; Greisen, Gorm; Herskind, Anna; Inguaggiato, Emanuela; Lorentzen, Jakob; Nielsen, Jens Bo; Sicola, Elisa

2014-10-15

Preterm infants are at risk for neurodevelopmental disorders, including motor, cognitive or behavioural problems, which may potentially be modified by early intervention. The EU CareToy Project Consortium (http://www.caretoy.eu) has developed a new modular system for intensive, individualized, home-based and family-centred early intervention, managed remotely by rehabilitation staff. A randomised controlled trial (RCT) has been designed to evaluate the efficacy of CareToy training in a first sample of low-risk preterm infants. The trial, randomised, multi-center, evaluator-blinded, parallel group controlled, is designed according to CONSORT Statement. Eligible subjects are infants born preterm without major complications, aged 3-9 months of corrected age with specific gross-motor abilities defined by Ages & Stages Questionnaire scores. Recruited infants, whose parents will sign a written informed consent for participation, will be randomized in CareToy training and control groups at baseline (T0). CareToy group will perform four weeks of personalized activities with the CareToy system, customized by the rehabilitation staff. The control group will continue standard care. Infant Motor Profile Scale is the primary outcome measure and a total sample size of 40 infants has been established. Bayley-Cognitive subscale, Alberta Infants Motor Scale and Teller Acuity Cards are secondary outcome measures. All measurements will be performed at T0 and at the end of training/control period (T1). For ethical reasons, after this first phase infants enrolled in the control group will perform the CareToy training, while the training group will continue standard care. At the end of open phase (T2) all infants will be assessed as at T1. Further assessment will be performed at 18 months corrected age (T3) to evaluate the long-term effects on neurodevelopmental outcome. Caregivers and rehabilitation staff will not be blinded whereas all the clinical assessments will be performed, videotaped and scored by blind assessors. The trial is ongoing and it is expected to be completed by April 2015. This paper describes RCT methodology to evaluate CareToy as a new tool for early intervention in preterm infants, first contribution to test this new type of system. It presents background, hypotheses, outcome measures and trial methodology. ClinicalTrials.gov: NCT01990183. EU grant ICT-2011.5.1-287932.

Advanced Shock Position Control for Mode Transition in a Turbine Based Combined Cycle Engine Inlet Model

NASA Technical Reports Server (NTRS)

Csank, Jeffrey T.; Stueber, Thomas J.

2013-01-01

A dual flow-path inlet system is being tested to evaluate methodologies for a Turbine Based Combined Cycle (TBCC) propulsion system to perform a controlled inlet mode transition. Prior to experimental testing, simulation models are used to test, debug, and validate potential control algorithms. One simulation package being used for testing is the High Mach Transient Engine Cycle Code simulation, known as HiTECC. This paper discusses the closed loop control system, which utilizes a shock location sensor to improve inlet performance and operability. Even though the shock location feedback has a coarse resolution, the feedback allows for a reduction in steady state error and, in some cases, better performance than with previous proposed pressure ratio based methods. This paper demonstrates the design and benefit with the implementation of a proportional-integral controller, an H-Infinity based controller, and a disturbance observer based controller.

Distributed control of large space antennas

NASA Technical Reports Server (NTRS)

Cameron, J. M.; Hamidi, M.; Lin, Y. H.; Wang, S. J.

1983-01-01

A systematic way to choose control design parameters and to evaluate performance for large space antennas is presented. The structural dynamics and control properties for a Hoop and Column Antenna and a Wrap-Rib Antenna are characterized. Some results of the effects of model parameter uncertainties to the stability, surface accuracy, and pointing errors are presented. Critical dynamics and control problems for these antenna configurations are identified and potential solutions are discussed. It was concluded that structural uncertainties and model error can cause serious performance deterioration and can even destabilize the controllers. For the hoop and column antenna, large hoop and long meat and the lack of stiffness between the two substructures result in low structural frequencies. Performance can be improved if this design can be strengthened. The two-site control system is more robust than either single-site control systems for the hoop and column antenna.

Air Traffic Control Experimentation and Evaluation with the NASA ATS-6 Satellite : Volume 7. Aircraft Antenna Evaluation Test

DOT National Transportation Integrated Search

1976-09-01

Aircraft L-band antennas designed for satellite communication were evaluated using an FAA KC-135 aircraft and the NASA ATS-6 satellite. All tests were performed between September 1974 and April 1975 as one component of the U.S. DOT/FAA aeronautical t...

Tracking Control and System Development for Laser-Driven Micro-Vehicles

NASA Astrophysics Data System (ADS)

Kajiwara, Itsuro; Hoshino, Kentaro; Hara, Shinji; Shiokata, Daisuke; Yabe, Takashi

The purpose of this paper is to design a control system for an integrated laser propulsion/tracking system to achieve continuous motion and control of laser-driven micro-vehicles. Laser propulsion is significant in achieving miniature and light micro-vehicles. A laser-driven micro-airplane has been studied using a paper airplane and YAG laser, resulting in successful gliding of the airplane. High-performance laser tracking control is required to achieve continuous flight. This paper presents a control design strategy based on the generalized Kalman-Yakubovic-Popov lemma to achieve this requirement. Experiments have been carried out to evaluate the performance of the integrated laser propulsion/tracking system.

Fuzzy Regulator Design for Wind Turbine Yaw Control

PubMed Central

Koulouras, Grigorios

2014-01-01

This paper proposes the development of an advanced fuzzy logic controller which aims to perform intelligent automatic control of the yaw movement of wind turbines. The specific fuzzy controller takes into account both the wind velocity and the acceptable yaw error correlation in order to achieve maximum performance efficacy. In this way, the proposed yaw control system is remarkably adaptive to the existing conditions. In this way, the wind turbine is enabled to retain its power output close to its nominal value and at the same time preserve its yaw system from pointless movement. Thorough simulation tests evaluate the proposed system effectiveness. PMID:24693237

Load Frequency Control of AC Microgrid Interconnected Thermal Power System

NASA Astrophysics Data System (ADS)

Lal, Deepak Kumar; Barisal, Ajit Kumar

2017-08-01

In this paper, a microgrid (MG) power generation system is interconnected with a single area reheat thermal power system for load frequency control study. A new meta-heuristic optimization algorithm i.e. Moth-Flame Optimization (MFO) algorithm is applied to evaluate optimal gains of the fuzzy based proportional, integral and derivative (PID) controllers. The system dynamic performance is studied by comparing the results with MFO optimized classical PI/PID controllers. Also the system performance is investigated with fuzzy PID controller optimized by recently developed grey wolf optimizer (GWO) algorithm, which has proven its superiority over other previously developed algorithm in many interconnected power systems.

Impact on learning of an e-learning module on leukaemia: a randomised controlled trial.

PubMed

Morgulis, Yuri; Kumar, Rakesh K; Lindeman, Robert; Velan, Gary M

2012-05-28

e-learning resources may be beneficial for complex or conceptually difficult topics. Leukaemia is one such topic, yet there are no reports on the efficacy of e-learning for leukaemia. This study compared the learning impact on senior medical students of a purpose-built e-learning module on leukaemia, compared with existing online resources. A randomised controlled trial was performed utilising volunteer senior medical students. Participants were randomly allocated to Study and Control groups. Following a pre-test on leukaemia administered to both groups, the Study group was provided with access to the new e-learning module, while the Control group was directed to existing online resources. A post-test and an evaluation questionnaire were administered to both groups at the end of the trial period. Study and Control groups were equivalent in gender distribution, mean academic ability, pre-test performance and time studying leukaemia during the trial. The Study group performed significantly better than the Control group in the post-test, in which the group to which the students had been allocated was the only significant predictor of performance. The Study group's evaluation of the module was overwhelmingly positive. A targeted e-learning module on leukaemia had a significant effect on learning in this cohort, compared with existing online resources. We believe that the interactivity, dialogic feedback and integration with the curriculum offered by the e-learning module contributed to its impact. This has implications for e-learning design in medicine and other disciplines.

Interpersonal relationship modulates brain responses to outcome evaluation when gambling for/against others: an electrophysiological analysis.

PubMed

Leng, Yue; Zhou, Xiaolin

2014-10-01

When individuals play a gambling task and their actions have consequences for observers, how are the brain responses of the performers modulated by their interpersonal relationship with the observers? To address this issue, we examined the event-related potentials responses in performers while they played two gambling games: one during which they tried to earn money for the observers instead of themselves (i.e., Experiment 1) and another gambling game during which they attempted to earn money from the observers (i.e., Experiment 2). In Experiment 1, ERP results showed that when gambling for either the friends or the strangers, the feedback-related negativity (FRN) responses were more negative-going to the losses than to the gains. The FRN effect (loss minus gain) was significantly larger when gambling for the friends than for the strangers. The general P300 response was more positive-going when gambling for the friends than for the strangers. These results suggested that gambling for others enables individuals to assess the outcome from the interests of the other people, consequently, the FRN response may be driven by the evaluative process related to interests of the others. Because one׳s own economic interests were not involved, the performers׳ brain responses during both the early, semi-automatic stage (i.e., the FRN) and the later, controlled stage (i.e., the P300) of outcome evaluation were modulated by the interpersonal relationship between the performers and the observers. In Experiment 2, ERP results revealed that when gambling against others, the FRN response was more negative-going to the losses than to the gains, as well. However, neither the FRN effect nor the general FRN response was modulated by interpersonal relationship. The general P300 response was more positive-going when gambling against the stranger than against the friend. These results suggested that when gambling against others, the performers׳ FRN response may be driven by two evaluative processes: one is related to the interests of their own, and another is related to the interests of the other people; and the former one plays a dominant role. Because of highly self-involvement, only the performers׳ brain responses during the later controlled stage of outcome evaluation were modulated by interpersonal relationship. The present study extended previous research on brain responses to outcome evaluation when decision making actions have consequences for the other people by suggesting that the FRN response in the performer could also be driven by two evaluative processes. In addition, whether the FRN in the performer was modulated by interpersonal relationship depends on which evaluative process plays a dominant role. However, the P300 in the performer could always be modulated by interpersonal relationship. These findings provide evidence on outcome evaluation being composed of an early semi-automatic primitive process and a later controlled cognitive/affective appraisal process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluating large-scale propensity score performance through real-world and synthetic data experiments.

PubMed

Tian, Yuxi; Schuemie, Martijn J; Suchard, Marc A

2018-06-22

Propensity score adjustment is a popular approach for confounding control in observational studies. Reliable frameworks are needed to determine relative propensity score performance in large-scale studies, and to establish optimal propensity score model selection methods. We detail a propensity score evaluation framework that includes synthetic and real-world data experiments. Our synthetic experimental design extends the 'plasmode' framework and simulates survival data under known effect sizes, and our real-world experiments use a set of negative control outcomes with presumed null effect sizes. In reproductions of two published cohort studies, we compare two propensity score estimation methods that contrast in their model selection approach: L1-regularized regression that conducts a penalized likelihood regression, and the 'high-dimensional propensity score' (hdPS) that employs a univariate covariate screen. We evaluate methods on a range of outcome-dependent and outcome-independent metrics. L1-regularization propensity score methods achieve superior model fit, covariate balance and negative control bias reduction compared with the hdPS. Simulation results are mixed and fluctuate with simulation parameters, revealing a limitation of simulation under the proportional hazards framework. Including regularization with the hdPS reduces commonly reported non-convergence issues but has little effect on propensity score performance. L1-regularization incorporates all covariates simultaneously into the propensity score model and offers propensity score performance superior to the hdPS marginal screen.

The study on the evaluation of the pollution control situation of the sewage systems in the counties and cities of Taiwan by applying the VIKOR method.

PubMed

Kuo, Jun-Yuan

2017-12-01

Currently, the pollution control situation of the sewage systems across Taiwan can be divided into the two major sewage systems, namely, industrial area sewage and public community sewage. When the counties and cities of Taiwan cannot effectively control the sewage pollution situation, ecological pollution of the environment and personal health damage would result. Therefore, evaluating the pollution control situation of the sewage systems can help the environmental protection authorities developing strategies for the pollution control of the sewage systems in the future. In this study, the Vise Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method was applied to evaluate the pollution control situation of the sewage systems. The water sample test qualification rate, the emission permit issuance rate, and the staff setting rate of the dedicated wastewater treatment company were used as the pollution control evaluation indexes. According to the results, the use of the VIKOR method to evaluate the pollution control situation of the sewage systems is effective. In cities and counties in Taiwan, public community sewage systems, dedicated to pollution control case, the public community should be actively coached in emission control technology to upgrade sewage capacity, the issuance of discharge permits, and the staff setting rate of the dedicated wastewater treatment, to improve public community sewage pollution control system capabilities. In Taiwan, the industrial area sewage systems, dedicated to pollution control situations, must pay attention to business units in raw materials, spare part inventory, and machine supplier of choice, and we must choose to meet environmental supply chain of green suppliers, which would be effective in reducing effluent produce and improve water sample test qualification rate. The VIKOR value of Yilan County is 1.0000, which is the worst in the pollution control of all the industrial area sewage systems, followed by Taoyuan County (0.2253) and Kaohsiung City (0.1334). Other cities and counties of Taiwan have good performance in the pollution control of the industrial area sewage systems. The VIKOR value of Kinmen County is 1.0000, which is the worst pollution control among the all public community sewage systems, followed by Hsinchu County (0.7458) and New Taipei City (0.5527). Among the cities and counties with good pollution control of the public community sewage systems, the best is Chiayi County (0.0000), followed by Kaohsiung City (0.0159) and Hsinchu City (0.0352). Chiayi County is a good performance compromise between all VIKOR values (0.0000), whether in industrial or public community area pollution control sewage systems. Yilan County industrial pollution control has the poorest performance of all the industrial area sewage systems in Taiwan, but in the public community, it ranked as fourth place of all the public community area sewage systems in Taiwan. The VIKOR method proposed in this study can effectively evaluate the pollution control situation of the sewage systems, and serve as a reference for the environmental protection authorities in developing the strategies for the pollution control of the sewage systems.

Collision avoidance system cost-benefit analysis : volume I - technical manual

DOT National Transportation Integrated Search

1981-09-01

Collision-avoidance systems under development in the U.S.A., Japan and Germany were evaluated. The performance evaluation showed that the signal processing and the control law of a system were the key parameters that decided the system's capability, ...

Evaluation of Commercially Available Chikungunya Virus Immunoglobulin M Detection Assays

PubMed Central

Johnson, Barbara W.; Goodman, Christin H.; Holloway, Kimberly; de Salazar, P. Martinez; Valadere, Anne M.; Drebot, Michael A.

2016-01-01

Commercial chikungunya virus (CHIKV)–specific IgM detection kits were evaluated at the Centers for Disease Control and Prevention (CDC), the Public Health Agency of Canada National Microbiology Laboratory, and the Caribbean Public Health Agency (CARPHA). The Euroimmun Anti-CHIKV IgM ELISA kit had ≥ 95% concordance with all three reference laboratory results. The limit of detection for low CHIK IgM+ samples, as measured by serial dilution of seven sera up to 1:12,800 ranged from 1:800 to 1:3,200. The Euroimmun IIFT kit evaluated at CDC and CARPHA performed well, but required more retesting of equivocal results. The InBios CHIKjj Detect MAC-ELISA had 100% and 98% concordance with CDC and CARPHA results, respectively, and had equal sensitivity to the CDC MAC-ELISA to 1:12,800 dilution in serially diluted samples. The Abcam Anti-CHIKV IgM ELISA had high performance at CARPHA, but at CDC, performance was inconsistent between lots. After replacement of the biotinylated IgM antibody controls with serum containing CHIKV-specific IgM and additional quality assurance/control measures, the Abcam kit was rereleased and reevaluated at CDC. The reformatted Abcam kit had 97% concordance with CDC results and limit of detection of 1:800 to 1:3,200. Two rapid tests and three other CHIKV MAC-ELISAs evaluated at CDC had low sensitivity, as the CDC CHIKV IgM in-house positive controls were below the level of detection. In conclusion, laboratories have options for CHIKV serological diagnosis using validated commercial kits. PMID:26976887

A time delay controller for magnetic bearings

NASA Technical Reports Server (NTRS)

Youcef-Toumi, K.; Reddy, S.

1991-01-01

The control of systems with unknown dynamics and unpredictable disturbances has raised some challenging problems. This is particularly important when high system performance needs to be guaranteed at all times. Recently, the Time Delay Control has been suggested as an alternative control scheme. The proposed control system does not require an explicit plant model nor does it depend on the estimation of specific plant parameters. Rather, it combines adaptation with past observations to directly estimate the effect of the plant dynamics. A control law is formulated for a class of dynamic systems and a sufficient condition is presented for control systems stability. The derivation is based on the bounded input-bounded output stability approach using L sub infinity function norms. The control scheme is implemented on a five degrees of freedom high speed and high precision magnetic bearing. The control performance is evaluated using step responses, frequency responses, and disturbance rejection properties. The experimental data show an excellent control performance despite the system complexity.

Defining standardized protocols for determining the efficacy of a postmilking teat disinfectant following experimental exposure of teats to mastitis pathogens.

PubMed

Schukken, Y H; Rauch, B J; Morelli, J

2013-04-01

The objective of this paper was to define standardized protocols for determining the efficacy of a postmilking teat disinfectant following experimental exposure of teats to both Staphylococcus aureus and Streptococcus agalactiae. The standardized protocols describe the selection of cows and herds and define the critical points in performing experimental exposure, performing bacterial culture, evaluating the culture results, and finally performing statistical analyses and reporting of the results. The protocols define both negative control and positive control trials. For negative control trials, the protocol states that an efficacy of reducing new intramammary infections (IMI) of at least 40% is required for a teat disinfectant to be considered effective. For positive control trials, noninferiority to a control disinfectant with a published efficacy of reducing new IMI of at least 70% is required. Sample sizes for both negative and positive control trials are calculated. Positive control trials are expected to require a large trial size. Statistical analysis methods are defined and, in the proposed methods, the rate of IMI may be analyzed using generalized linear mixed models. The efficacy of the test product can be evaluated while controlling for important covariates and confounders in the trial. Finally, standards for reporting are defined and reporting considerations are discussed. The use of the defined protocol is shown through presentation of the results of a recent trial of a test product against a negative control. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Delivery performance of conventional aircraft by terminal-area, time-based air traffic control: A real-time simulation evaluation

NASA Technical Reports Server (NTRS)

Credeur, Leonard; Houck, Jacob A.; Capron, William R.; Lohr, Gary W.

1990-01-01

A description and results are presented of a study to measure the performance and reaction of airline flight crews, in a full workload DC-9 cockpit, flying in a real-time simulation of an air traffic control (ATC) concept called Traffic Intelligence for the Management of Efficient Runway-scheduling (TIMER). Experimental objectives were to verify earlier fast-time TIMER time-delivery precision results and obtain data for the validation or refinement of existing computer models of pilot/airborne performance. Experimental data indicated a runway threshold, interarrival-time-error standard deviation in the range of 10.4 to 14.1 seconds. Other real-time system performance parameters measured include approach speeds, response time to controller turn instructions, bank angles employed, and ATC controller message delivery-time errors.

Antiwindup analysis and design approaches for MIMO systems

NASA Technical Reports Server (NTRS)

Marcopoli, Vincent R.; Phillips, Stephen M.

1994-01-01

Performance degradation of multiple-input multiple-output (MIMO) control systems having limited actuators is often handled by augmenting the controller with an antiwindup mechanism, which attempts to maintain system performance when limits are encountered. The goals of this paper are: (1) To develop a method to analyze antiwindup systems to determine precisely what stability and performance degradation is incurred under limited conditions. It is shown that by reformulating limited actuator commands as resulting from multiplicative perturbations to the corresponding controller requests, mu-analysis tools can be utilized to obtain quantitative measures of stability and performance degradation. (2) To propose a linear, time invariant (LTI) criterion on which to base the antiwindup design. These analysis and design methods are illustrated through the evaluation of two competing antiwindup schemes augmenting the controller of a Short Take-Off and Vertical Landing (STOVL) aircraft in transition flight.

Antiwindup analysis and design approaches for MIMO systems

NASA Technical Reports Server (NTRS)

Marcopoli, Vincent R.; Phillips, Stephen M.

1993-01-01

Performance degradation of multiple-input multiple-output (MIMO) control systems having limited actuators is often handled by augmenting the controller with an antiwindup mechanism, which attempts to maintain system performance when limits are encountered. The goals of this paper are: 1) to develop a method to analyze antiwindup systems to determine precisely what stability and performance degradation is incurred under limited conditions. It is shown that by reformulating limited actuator commands as resulting from multiplicative perturbations to the corresponding controller requests, mu-analysis tools can be utilized to obtain quantitative measures of stability and performance degradation. 2) To propose a linear, time invariant (LTI) criterion on which to base the antiwindup design. These analysis and design methods are illustrated through the evaluation of two competing antiwindup schemes augmenting the controller of a Short Take-Off and Vertical Landing (STOVL) aircraft in transition flight.

Designs and performance of three new microprocessor-controlled knee joints.

PubMed

Thiele, Julius; Schöllig, Christina; Bellmann, Malte; Kraft, Marc

2018-02-09

A crossover design study with a small group of subjects was used to evaluate the performance of three microprocessor-controlled exoprosthetic knee joints (MPKs): C-Leg 4, Plié 3 and Rheo Knee 3. Given that the mechanical designs and control algorithms of the joints determine the user outcome, the influence of these inherent differences on the functional characteristics was investigated in this study. The knee joints were evaluated during level-ground walking at different velocities in a motion analysis laboratory. Additionally, technical analyses using patents, technical documentations and X-ray computed tomography (CT) for each knee joint were performed. The technical analyses showed that only C-Leg 4 and Rheo Knee 3 allow microprocessor-controlled adaptation of the joint resistances for different gait velocities. Furthermore, Plié 3 is not able to provide stance extension damping. The biomechanical results showed that only if a knee joint adapts flexion and extension resistances by the microprocessor all known advantages of MPKs can become apparent. But not all users may benefit from the examined functions: e.g. a good accommodation to fast walking speeds or comfortable stance phase flexion. Hence, a detailed comparison of user demands and performance of the designated knee joint is mandatory to ensure a maximum in user outcome.

Evaluation of measurement data from a sensor system for breath control

NASA Astrophysics Data System (ADS)

Seifert, Rolf; Keller, Hubert B.; Conrad, Thorsten; Peter, Jens

2017-03-01

Binary ethanol-H2 gas samples were measured by an innovative mobile sensor system for the alcohol control in the respiratory air. The measurements were performed by a gas sensor operated by cyclic variation of the working temperature at the sensor head. The evaluation of the data, using an updated version of the evaluation procedure ProSens, results in a very good substance identification and concentration determination of the components of the gas mixture. The relative analysis errors were in all cases less than 9%.

Management of the General Process of Parenteral Nutrition Using mHealth Technologies: Evaluation and Validation Study

PubMed Central

2018-01-01

Background Any system applied to the control of parenteral nutrition (PN) ought to prove that the process meets the established requirements and include a repository of records to allow evaluation of the information about PN processes at any time. Objective The goal of the research was to evaluate the mobile health (mHealth) app and validate its effectiveness in monitoring the management of the PN process. Methods We studied the evaluation and validation of the general process of PN using an mHealth app. The units of analysis were the PN bags prepared and administered at the Son Espases University Hospital, Palma, Spain, from June 1 to September 6, 2016. For the evaluation of the app, we used the Poststudy System Usability Questionnaire and subsequent analysis with the Cronbach alpha coefficient. Validation was performed by checking the compliance of control for all operations on each of the stages (validation and transcription of the prescription, preparation, conservation, and administration) and by monitoring the operative control points and critical control points. Results The results obtained from 387 bags were analyzed, with 30 interruptions of administration. The fulfillment of stages was 100%, including noncritical nonconformities in the storage control. The average deviation in the weight of the bags was less than 5%, and the infusion time did not present deviations greater than 1 hour. Conclusions The developed app successfully passed the evaluation and validation tests and was implemented to perform the monitoring procedures for the overall PN process. A new mobile solution to manage the quality and traceability of sensitive medicines such as blood-derivative drugs and hazardous drugs derived from this project is currently being deployed. PMID:29615389

Analysis of Radio Frequency Surveillance Systems for Air Traffic Control : Volume 1. Text.

DOT National Transportation Integrated Search

1976-02-01

Performance criteria that afford quantitative evaluation of a variety of current and proposed configurations of the Air Traffic Control Radar Beacon System (ATCRBS) are described in detail. Two analytic system models are developed to allow applicatio...

Testbed-based Performance Evaluation of Attack Resilient Control for AGC

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

Ashok, Aditya; Sridhar, Siddharth; McKinnon, Archibald D.

The modern electric power grid is a complex cyber-physical system whose reliable operation is enabled by a wide-area monitoring and control infrastructure. This infrastructure, supported by an extensive communication backbone, enables several control applications functioning at multiple time scales to ensure the grid is maintained within stable operating limits. Recent events have shown that vulnerabilities in this infrastructure may be exploited to manipulate the data being exchanged. Such a scenario could cause the associated control application to mis-operate, potentially causing system-wide instabilities. There is a growing emphasis on looking beyond traditional cybersecurity solutions to mitigate such threats. In this papermore » we perform a testbed-based validation of one such solution - Attack Resilient Control (ARC) - on Iowa State University's \\textit{PowerCyber} testbed. ARC is a cyber-physical security solution that combines domain-specific anomaly detection and model-based mitigation to detect stealthy attacks on Automatic Generation Control (AGC). In this paper, we first describe the implementation architecture of the experiment on the testbed. Next, we demonstrate the capability of stealthy attack templates to cause forced under-frequency load shedding in a 3-area test system. We then validate the performance of ARC by measuring its ability to detect and mitigate these attacks. Our results reveal that ARC is efficient in detecting stealthy attacks and enables AGC to maintain system operating frequency close to its nominal value during an attack. Our studies also highlight the importance of testbed-based experimentation for evaluating the performance of cyber-physical security and control applications.« less

Nonlinear stability and control study of highly maneuverable high performance aircraft

NASA Technical Reports Server (NTRS)

Mohler, R. R.

1993-01-01

This project is intended to research and develop new nonlinear methodologies for the control and stability analysis of high-performance, high angle-of-attack aircraft such as HARV (F18). Past research (reported in our Phase 1, 2, and 3 progress reports) is summarized and more details of final Phase 3 research is provided. While research emphasis is on nonlinear control, other tasks such as associated model development, system identification, stability analysis, and simulation are performed in some detail as well. An overview of various models that were investigated for different purposes such as an approximate model reference for control adaptation, as well as another model for accurate rigid-body longitudinal motion is provided. Only a very cursory analysis was made relative to type 8 (flexible body dynamics). Standard nonlinear longitudinal airframe dynamics (type 7) with the available modified F18 stability derivatives, thrust vectoring, actuator dynamics, and control constraints are utilized for simulated flight evaluation of derived controller performance in all cases studied.

Cause or effect? The relationship between student perception of the medical school learning environment and academic performance on USMLE Step 1.

PubMed

Wayne, Sharon J; Fortner, Sally A; Kitzes, Judith A; Timm, Craig; Kalishman, Summers

2013-05-01

A school's learning environment is believed to influence academic performance yet few studies have evaluated this association controlling for prior academic ability, an important factor since students who do well in school tend to rate their school's environment more highly than students who are less academically strong. To evaluate the effect of student perception of the learning environment on their performance on a standardized licensing test while controlling for prior academic ability. We measured perception of the learning environment after the first year of medical school in 267 students from five consecutive classes and related that measure to performance on United States Medical Licensing Examination (USMLE) Step 1, taken approximately six months later. We controlled for prior academic performance by including Medical College Admission Test score and undergraduate grade point average in linear regression models. Three of the five learning environment subscales were statistically associated with Step 1 performance (p < 0.05): meaningful learning environment, emotional climate, and student-student interaction. A one-point increase in the rating of the subscales (scale of 1-4) was associated with increases of 6.8, 6.6, and 4.8 points on the Step 1 exam. Our findings provide some evidence for the widely held assumption that a positively perceived learning environment contributes to better academic performance.

Shape Control of Plates with Piezo Actuators and Collocated Position/Rate Sensors

NASA Technical Reports Server (NTRS)

Balakrishnan, A. V.

1994-01-01

This paper treats the control problem of shaping the surface deformation of a circular plate using embedded piezo-electric actuators and collocated rate sensors. An explicit Linear Quadratic Gaussian (LQG) optimizer stability augmentation compensator is derived as well as the optimal feed-forward control. Corresponding performance evaluation formulas are also derived.

Shape Control of Plates with Piezo Actuators and Collocated Position/Rate Sensors

NASA Technical Reports Server (NTRS)

Balakrishnan, A. V.

1994-01-01

This paper treats the control problem of shaping the surface deformation of a circular plate using embedded piezo-electric actuator and collocated rate sensors. An explicit Linear Quadratic Gaussian (LQG) optimizer stability augmentation compensator is derived as well as the optimal feed-forward control. Corresponding performance evaluation formulas are also derived.

Evaluation of the USDA Northeast Area-wide Tick Control Project by Meta-analysis

USDA-ARS?s Scientific Manuscript database

As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using USDA ‘4-Poster’ devices to deliver targeted-acaricide to white-tailed d...