Evaluating the dynamic response of in-flight thrust calculation techniques during throttle transients

NASA Technical Reports Server (NTRS)

Ray, Ronald J.

1994-01-01

New flight test maneuvers and analysis techniques for evaluating the dynamic response of in-flight thrust models during throttle transients have been developed and validated. The approach is based on the aircraft and engine performance relationship between thrust and drag. Two flight test maneuvers, a throttle step and a throttle frequency sweep, were developed and used in the study. Graphical analysis techniques, including a frequency domain analysis method, were also developed and evaluated. They provide quantitative and qualitative results. Four thrust calculation methods were used to demonstrate and validate the test technique. Flight test applications on two high-performance aircraft confirmed the test methods as valid and accurate. These maneuvers and analysis techniques were easy to implement and use. Flight test results indicate the analysis techniques can identify the combined effects of model error and instrumentation response limitations on the calculated thrust value. The methods developed in this report provide an accurate approach for evaluating, validating, or comparing thrust calculation methods for dynamic flight applications.

Computer systems performance measurement techniques.

DOT National Transportation Integrated Search

1971-06-01

Computer system performance measurement techniques, tools, and approaches are presented as a foundation for future recommendations regarding the instrumentation of the ARTS ATC data processing subsystem for purposes of measurement and evaluation.

Comparison of machine learning techniques to predict all-cause mortality using fitness data: the Henry ford exercIse testing (FIT) project.

PubMed

Sakr, Sherif; Elshawi, Radwa; Ahmed, Amjad M; Qureshi, Waqas T; Brawner, Clinton A; Keteyian, Steven J; Blaha, Michael J; Al-Mallah, Mouaz H

2017-12-19

Prior studies have demonstrated that cardiorespiratory fitness (CRF) is a strong marker of cardiovascular health. Machine learning (ML) can enhance the prediction of outcomes through classification techniques that classify the data into predetermined categories. The aim of this study is to present an evaluation and comparison of how machine learning techniques can be applied on medical records of cardiorespiratory fitness and how the various techniques differ in terms of capabilities of predicting medical outcomes (e.g. mortality). We use data of 34,212 patients free of known coronary artery disease or heart failure who underwent clinician-referred exercise treadmill stress testing at Henry Ford Health Systems Between 1991 and 2009 and had a complete 10-year follow-up. Seven machine learning classification techniques were evaluated: Decision Tree (DT), Support Vector Machine (SVM), Artificial Neural Networks (ANN), Naïve Bayesian Classifier (BC), Bayesian Network (BN), K-Nearest Neighbor (KNN) and Random Forest (RF). In order to handle the imbalanced dataset used, the Synthetic Minority Over-Sampling Technique (SMOTE) is used. Two set of experiments have been conducted with and without the SMOTE sampling technique. On average over different evaluation metrics, SVM Classifier has shown the lowest performance while other models like BN, BC and DT performed better. The RF classifier has shown the best performance (AUC = 0.97) among all models trained using the SMOTE sampling. The results show that various ML techniques can significantly vary in terms of its performance for the different evaluation metrics. It is also not necessarily that the more complex the ML model, the more prediction accuracy can be achieved. The prediction performance of all models trained with SMOTE is much better than the performance of models trained without SMOTE. The study shows the potential of machine learning methods for predicting all-cause mortality using cardiorespiratory fitness data.

Data analysis techniques used at the Oak Ridge Y-12 plant flywheel evaluation laboratory

NASA Astrophysics Data System (ADS)

Steels, R. S., Jr.; Babelay, E. F., Jr.

1980-07-01

Some of the more advanced data analysis techniques applied to the problem of experimentally evaluating the performance of high performance composite flywheels are presented. Real time applications include polar plots of runout with interruptions relating to balance and relative motions between parts, radial growth measurements, and temperature of the spinning part. The technique used to measure torque applied to a containment housing during flywheel failure is also presented. The discussion of pre and post test analysis techniques includes resonant frequency determination with modal analysis, waterfall charts, and runout signals at failure.

A computer technique for detailed analysis of mission radius and maneuverability characteristics of fighter aircraft

NASA Technical Reports Server (NTRS)

Foss, W. E., Jr.

1981-01-01

A computer technique to determine the mission radius and maneuverability characteristics of combat aircraft was developed. The technique was used to determine critical operational requirements and the areas in which research programs would be expected to yield the most beneficial results. In turn, the results of research efforts were evaluated in terms of aircraft performance on selected mission segments and for complete mission profiles. Extensive use of the technique in evaluation studies indicates that the calculated performance is essentially the same as that obtained by the proprietary programs in use throughout the aircraft industry.

Strapdown system performance optimization test evaluations (SPOT), volume 1

NASA Technical Reports Server (NTRS)

Blaha, R. J.; Gilmore, J. P.

1973-01-01

A three axis inertial system was packaged in an Apollo gimbal fixture for fine grain evaluation of strapdown system performance in dynamic environments. These evaluations have provided information to assess the effectiveness of real-time compensation techniques and to study system performance tradeoffs to factors such as quantization and iteration rate. The strapdown performance and tradeoff studies conducted include: (1) Compensation models and techniques for the inertial instrument first-order error terms were developed and compensation effectivity was demonstrated in four basic environments; single and multi-axis slew, and single and multi-axis oscillatory. (2) The theoretical coning bandwidth for the first-order quaternion algorithm expansion was verified. (3) Gyro loop quantization was identified to affect proportionally the system attitude uncertainty. (4) Land navigation evaluations identified the requirement for accurate initialization alignment in order to pursue fine grain navigation evaluations.

Evaluating the performance of a fault detection and diagnostic system for vapor compression equipment

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

Breuker, M.S.; Braun, J.E.

This paper presents a detailed evaluation of the performance of a statistical, rule-based fault detection and diagnostic (FDD) technique presented by Rossi and Braun (1997). Steady-state and transient tests were performed on a simple rooftop air conditioner over a range of conditions and fault levels. The steady-state data without faults were used to train models that predict outputs for normal operation. The transient data with faults were used to evaluate FDD performance. The effect of a number of design variables on FDD sensitivity for different faults was evaluated and two prototype systems were specified for more complete evaluation. Good performancemore » was achieved in detecting and diagnosing five faults using only six temperatures (2 input and 4 output) and linear models. The performance improved by about a factor of two when ten measurements (three input and seven output) and higher order models were used. This approach for evaluating and optimizing the performance of the statistical, rule-based FDD technique could be used as a design and evaluation tool when applying this FDD method to other packaged air-conditioning systems. Furthermore, the approach could also be modified to evaluate the performance of other FDD methods.« less

Study to perform preliminary experiments to evaluate particle generation and characterization techniques for zero-gravity cloud physics experiments

NASA Technical Reports Server (NTRS)

Katz, U.

1982-01-01

Methods of particle generation and characterization with regard to their applicability for experiments requiring cloud condensation nuclei (CCN) of specified properties were investigated. Since aerosol characterization is a prerequisite to assessing performance of particle generation equipment, techniques for characterizing aerosol were evaluated. Aerosol generation is discussed, and atomizer and photolytic generators including preparation of hydrosols (used with atomizers) and the evaluation of a flight version of an atomizer are studied.

Empirical performance of interpolation techniques in risk-neutral density (RND) estimation

NASA Astrophysics Data System (ADS)

Bahaludin, H.; Abdullah, M. H.

2017-03-01

The objective of this study is to evaluate the empirical performance of interpolation techniques in risk-neutral density (RND) estimation. Firstly, the empirical performance is evaluated by using statistical analysis based on the implied mean and the implied variance of RND. Secondly, the interpolation performance is measured based on pricing error. We propose using the leave-one-out cross-validation (LOOCV) pricing error for interpolation selection purposes. The statistical analyses indicate that there are statistical differences between the interpolation techniques:second-order polynomial, fourth-order polynomial and smoothing spline. The results of LOOCV pricing error shows that interpolation by using fourth-order polynomial provides the best fitting to option prices in which it has the lowest value error.

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.

Improved Sectional Image Analysis Technique for Evaluating Fiber Orientations in Fiber-Reinforced Cement-Based Materials.

PubMed

Lee, Bang Yeon; Kang, Su-Tae; Yun, Hae-Bum; Kim, Yun Yong

2016-01-12

The distribution of fiber orientation is an important factor in determining the mechanical properties of fiber-reinforced concrete. This study proposes a new image analysis technique for improving the evaluation accuracy of fiber orientation distribution in the sectional image of fiber-reinforced concrete. A series of tests on the accuracy of fiber detection and the estimation performance of fiber orientation was performed on artificial fiber images to assess the validity of the proposed technique. The validation test results showed that the proposed technique estimates the distribution of fiber orientation more accurately than the direct measurement of fiber orientation by image analysis.

Improved Sectional Image Analysis Technique for Evaluating Fiber Orientations in Fiber-Reinforced Cement-Based Materials

PubMed Central

Lee, Bang Yeon; Kang, Su-Tae; Yun, Hae-Bum; Kim, Yun Yong

2016-01-01

The distribution of fiber orientation is an important factor in determining the mechanical properties of fiber-reinforced concrete. This study proposes a new image analysis technique for improving the evaluation accuracy of fiber orientation distribution in the sectional image of fiber-reinforced concrete. A series of tests on the accuracy of fiber detection and the estimation performance of fiber orientation was performed on artificial fiber images to assess the validity of the proposed technique. The validation test results showed that the proposed technique estimates the distribution of fiber orientation more accurately than the direct measurement of fiber orientation by image analysis. PMID:28787839

Statistical Evaluation of Time Series Analysis Techniques

NASA Technical Reports Server (NTRS)

Benignus, V. A.

1973-01-01

The performance of a modified version of NASA's multivariate spectrum analysis program is discussed. A multiple regression model was used to make the revisions. Performance improvements were documented and compared to the standard fast Fourier transform by Monte Carlo techniques.

Extending the Distributed Lag Model framework to handle chemical mixtures.

PubMed

Bello, Ghalib A; Arora, Manish; Austin, Christine; Horton, Megan K; Wright, Robert O; Gennings, Chris

2017-07-01

Distributed Lag Models (DLMs) are used in environmental health studies to analyze the time-delayed effect of an exposure on an outcome of interest. Given the increasing need for analytical tools for evaluation of the effects of exposure to multi-pollutant mixtures, this study attempts to extend the classical DLM framework to accommodate and evaluate multiple longitudinally observed exposures. We introduce 2 techniques for quantifying the time-varying mixture effect of multiple exposures on an outcome of interest. Lagged WQS, the first technique, is based on Weighted Quantile Sum (WQS) regression, a penalized regression method that estimates mixture effects using a weighted index. We also introduce Tree-based DLMs, a nonparametric alternative for assessment of lagged mixture effects. This technique is based on the Random Forest (RF) algorithm, a nonparametric, tree-based estimation technique that has shown excellent performance in a wide variety of domains. In a simulation study, we tested the feasibility of these techniques and evaluated their performance in comparison to standard methodology. Both methods exhibited relatively robust performance, accurately capturing pre-defined non-linear functional relationships in different simulation settings. Further, we applied these techniques to data on perinatal exposure to environmental metal toxicants, with the goal of evaluating the effects of exposure on neurodevelopment. Our methods identified critical neurodevelopmental windows showing significant sensitivity to metal mixtures. Copyright © 2017 Elsevier Inc. All rights reserved.

Noninvasive evaluation system of fractured bone based on speckle interferometry

NASA Astrophysics Data System (ADS)

Yamanada, Shinya; Murata, Shigeru; Tanaka, Yohsuke

2010-11-01

This paper presents a noninvasive evaluation system of fractured bone based on speckle interferometry using a modified evaluation index for higher performance, and the experiments are carried out to examine the feasibility in evaluating bone fracture healing and the influence of some system parameters on the performance. From experimental results, it is shown that the presence of fractured part of bone and the state of bone fracture healing are successfully estimated by observing fine speckle fringes on the object surface. The proposed evaluation index also can successfully express the difference between the cases with cut and without it. Since most system parameters are found not to affect the performance of the present technique, the present technique is expected to be applied to various patients that have considerable individual variability.

Comparison of Two Variants Of a Kata Technique (Unsu): The Neuromechanical Point of View

PubMed Central

Camomilla, Valentina; Sbriccoli, Paola; Mario, Alberto Di; Arpante, Alessandro; Felici, Francesco

2009-01-01

The objective of this work was to characterize from a neuromechanical point of view a jump performed within the sequence of Kata Unsu in International top level karateka. A modified jumping technique was proposed to improve the already acquired technique. The neuromechanical evaluation, paralleled by a refereeing judgment, was then used to compare modified and classic technique to test if the modification could lead to a better performance capacity, e.g. a higher score during an official competition. To this purpose, four high ranked karateka were recruited and instructed to perform the two jumps. Surface electromyographic signals were recorded in a bipolar mode from the vastus lateralis, rectus femoris, biceps femoris, gluteus maximus, and gastrocnemious muscles of both lower limbs. Mechanical data were collected by means of a stereophotogrammetric system and force platforms. Performance was associated to parameters characterizing the initial conditions of the aerial phase and to the CoM maximal height. The most critical elements having a negative influence on the arbitral evaluation were associated to quantitative error indicators. 3D reconstruction of the movement and videos were used to obtain the referee scores. The Unsu jump was divided into five phases (preparation, take off, ascending flight, descending flight, and landing) and the critical elements were highlighted. When comparing the techniques, no difference was found in the pattern of sEMG activation of the throwing leg muscles, while the push leg showed an earlier activation of RF and GA muscles at the beginning of the modified technique. The only significant improvement associated with the modified technique was evidenced at the beginning of the aerial phase, while there was no significant improvement of the referee score. Nevertheless, the proposed neuromechanical analysis, finalized to correlate technique features with the core performance indicators, is new in the field and is a promising tool to perform further analyses. Key Points A quantitative phase analysis, highlighting the critical features of the technique, was provided for the jump executed during the Kata Unsu. Kinematics and neuromuscular activity can be assessed during the Kata Unsu jump performed by top level karateka. Neuromechanical parameters change during different Kata Unsu jump techniques. Appropriate performance capacity indicators based on the neuromechanical evaluation can describe changes due to a modification of the technique. PMID:24474884

A Comparative Study of Unsupervised Anomaly Detection Techniques Using Honeypot Data

NASA Astrophysics Data System (ADS)

Song, Jungsuk; Takakura, Hiroki; Okabe, Yasuo; Inoue, Daisuke; Eto, Masashi; Nakao, Koji

Intrusion Detection Systems (IDS) have been received considerable attention among the network security researchers as one of the most promising countermeasures to defend our crucial computer systems or networks against attackers on the Internet. Over the past few years, many machine learning techniques have been applied to IDSs so as to improve their performance and to construct them with low cost and effort. Especially, unsupervised anomaly detection techniques have a significant advantage in their capability to identify unforeseen attacks, i.e., 0-day attacks, and to build intrusion detection models without any labeled (i.e., pre-classified) training data in an automated manner. In this paper, we conduct a set of experiments to evaluate and analyze performance of the major unsupervised anomaly detection techniques using real traffic data which are obtained at our honeypots deployed inside and outside of the campus network of Kyoto University, and using various evaluation criteria, i.e., performance evaluation by similarity measurements and the size of training data, overall performance, detection ability for unknown attacks, and time complexity. Our experimental results give some practical and useful guidelines to IDS researchers and operators, so that they can acquire insight to apply these techniques to the area of intrusion detection, and devise more effective intrusion detection models.

The Influence of Body Mapping on Student Musicians' Performance Experiences

ERIC Educational Resources Information Center

Buchanan, Heather J.; Hays, Terrence

2014-01-01

This qualitative study examines student musicians' perceptions of their performance and development resulting from Body Mapping (BMG) technique. BMG is a somatic (mind-body) education technique designed to teach musicians skills in self-evaluation and change for performing with sensory-motor integrity. A qualitative study guided by an…

Grazing Incidence Wavefront Sensing and Verification of X-Ray Optics Performance

NASA Technical Reports Server (NTRS)

Saha, Timo T.; Rohrbach, Scott; Zhang, William W.

2011-01-01

Evaluation of interferometrically measured mirror metrology data and characterization of a telescope wavefront can be powerful tools in understanding of image characteristics of an x-ray optical system. In the development of soft x-ray telescope for the International X-Ray Observatory (IXO), we have developed new approaches to support the telescope development process. Interferometrically measuring the optical components over all relevant spatial frequencies can be used to evaluate and predict the performance of an x-ray telescope. Typically, the mirrors are measured using a mount that minimizes the mount and gravity induced errors. In the assembly and mounting process the shape of the mirror segments can dramatically change. We have developed wavefront sensing techniques suitable for the x-ray optical components to aid us in the characterization and evaluation of these changes. Hartmann sensing of a telescope and its components is a simple method that can be used to evaluate low order mirror surface errors and alignment errors. Phase retrieval techniques can also be used to assess and estimate the low order axial errors of the primary and secondary mirror segments. In this paper we describe the mathematical foundation of our Hartmann and phase retrieval sensing techniques. We show how these techniques can be used in the evaluation and performance prediction process of x-ray telescopes.

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

A performance evaluation postprocessor for computer-aided design and analysis of communication systems

NASA Technical Reports Server (NTRS)

Tranter, W. H.

1979-01-01

A technique for estimating the signal-to-noise ratio at a point in a digital simulation of a communication system is described; the technique is essentially a digital realization of a technique proposed by Shepertycki (1964) for the evaluation of analog communication systems. Signals having lowpass or bandpass spectra may be used. Simulation results show the technique to be accurate over a wide range of signal-to-noise ratios.

Models and techniques for evaluating the effectiveness of aircraft computing systems

NASA Technical Reports Server (NTRS)

Meyer, J. F.

1977-01-01

Models, measures and techniques were developed for evaluating the effectiveness of aircraft computing systems. The concept of effectiveness involves aspects of system performance, reliability and worth. Specifically done was a detailed development of model hierarchy at mission, functional task, and computational task levels. An appropriate class of stochastic models was investigated which served as bottom level models in the hierarchial scheme. A unified measure of effectiveness called 'performability' was defined and formulated.

Clinical performance of porcelain laminate veneers: outcomes of the aesthetic pre-evaluative temporary (APT) technique.

PubMed

Gurel, Galip; Morimoto, Susana; Calamita, Marcelo A; Coachman, Christian; Sesma, Newton

2012-12-01

This article evaluates the long-term clinical performance of porcelain laminate veneers bonded to teeth prepared with the use of an additive mock-up and aesthetic pre-evaluative temporary (APT) technique over a 12-year period. Sixty-six patients were restored with 580 porcelain laminate veneers. The technique, used for diagnosis, esthetic design, tooth preparation, and provisional restoration fabrication, was based on the APT protocol. The influence of several factors on the durability of veneers was analyzed according to pre- and postoperative parameters. With utilization of the APT restoration, over 80% of tooth preparations were confined to the dental enamel. Over 12 years, 42 laminate veneers failed, but when the preparations were limited to the enamel, the failure rate resulting from debonding and microleakage decreased to 0%. Porcelain laminate veneers presented a successful clinical performance in terms of marginal adaptation, discoloration, gingival recession, secondary caries, postoperative sensitivity, and satisfaction with restoration shade at the end of 12 years. The APT technique facilitated diagnosis, communication, and preparation, providing predictability for the restorative treatment. Limiting the preparation depth to the enamel surface significantly increases the performance of porcelain laminate veneers.

A Compendium of Assessment Techniques.

ERIC Educational Resources Information Center

Knapp, Joan; Sharon, Amiel

A wide variety of techniques are appropriate for evaluating different types of experiential learning. This monograph includes sections on performance tests, simulations, interviews, ratings, self evaluation, and product assessment. Each section orients the reader to one of these general types of assessment and then provides brief illustrations of…

Performance evaluation using SYSTID time domain simulation. [computer-aid design and analysis for communication systems

NASA Technical Reports Server (NTRS)

Tranter, W. H.; Ziemer, R. E.; Fashano, M. J.

1975-01-01

This paper reviews the SYSTID technique for performance evaluation of communication systems using time-domain computer simulation. An example program illustrates the language. The inclusion of both Gaussian and impulse noise models make accurate simulation possible in a wide variety of environments. A very flexible postprocessor makes possible accurate and efficient performance evaluation.

Design and Evaluation of Fusion Approach for Combining Brain and Gaze Inputs for Target Selection

PubMed Central

Évain, Andéol; Argelaguet, Ferran; Casiez, Géry; Roussel, Nicolas; Lécuyer, Anatole

2016-01-01

Gaze-based interfaces and Brain-Computer Interfaces (BCIs) allow for hands-free human–computer interaction. In this paper, we investigate the combination of gaze and BCIs. We propose a novel selection technique for 2D target acquisition based on input fusion. This new approach combines the probabilistic models for each input, in order to better estimate the intent of the user. We evaluated its performance against the existing gaze and brain–computer interaction techniques. Twelve participants took part in our study, in which they had to search and select 2D targets with each of the evaluated techniques. Our fusion-based hybrid interaction technique was found to be more reliable than the previous gaze and BCI hybrid interaction techniques for 10 participants over 12, while being 29% faster on average. However, similarly to what has been observed in hybrid gaze-and-speech interaction, gaze-only interaction technique still provides the best performance. Our results should encourage the use of input fusion, as opposed to sequential interaction, in order to design better hybrid interfaces. PMID:27774048

Non-destructive characterization of SiC coated carbon-carbon composites by multiple techniques

NASA Astrophysics Data System (ADS)

Nixon, Thomas D.; Hemstad, Stan N.; Pfeifer, William H.

SiC coated carbon-carbon composites were evaluated using several non-destructive techniques as a means of quantifying the quality of both the coating and substrate. The techniques employed included dye penetrant infiltration, eddy current measurement, C-scan, and computed tomography (CT). The NDE results were then correlated to oxidation performance and destructive evaluations by electron and optical microscopy.

A new technique for measuring listening and reading literacy in developing countries

NASA Astrophysics Data System (ADS)

Greene, Barbara A.; Royer, James M.; Anzalone, Stephen

1990-03-01

One problem in evaluating educational interventions in developing countries is the absence of tests that adequately reflect the culture and curriculum. The Sentence Verification Technique is a new procedure for measuring reading and listening comprehension that allows for the development of tests based on materials indigenous to a given culture. The validity of using the Sentence Verification Technique to measure reading comprehension in Grenada was evaluated in the present study. The study involved 786 students at standards 3, 4 and 5. The tests for each standard consisted of passages that varied in difficulty. The students identified as high ability students in all three standards performed better than those identified as low ability. All students performed better with easier passages. Additionally, students in higher standards performed bettter than students in lower standards on a given passage. These results supported the claim that the Sentence Verification Technique is a valid measure of reading comprehension in Grenada.

Evaluation of techniques for handling missing cost-to-charge ratios in the USA Nationwide Inpatient Sample: a simulation study.

PubMed

Yu, Tzy-Chyi; Zhou, Huanxue

2015-09-01

Evaluate performance of techniques used to handle missing cost-to-charge ratio (CCR) data in the USA Healthcare Cost and Utilization Project's Nationwide Inpatient Sample. Four techniques to replace missing CCR data were evaluated: deleting discharges with missing CCRs (complete case analysis), reweighting as recommended by Healthcare Cost and Utilization Project, reweighting by adjustment cells and hot deck imputation by adjustment cells. Bias and root mean squared error of these techniques on hospital cost were evaluated in five disease cohorts. Similar mean cost estimates would be obtained with any of the four techniques when the percentage of missing data is low (<10%). When total cost is the outcome of interest, a reweighting technique to avoid underestimation from dropping observations with missing data should be adopted.

Analyzing Teaching Performance of Instructors Using Data Mining Techniques

ERIC Educational Resources Information Center

Mardikyan, Sona; Badur, Bertain

2011-01-01

Student evaluations to measure the teaching effectiveness of instructor's are very frequently applied in higher education for many years. This study investigates the factors associated with the assessment of instructors teaching performance using two different data mining techniques; stepwise regression and decision trees. The data collected…

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.

Simplified Techniques for Evaluation and Interpretation of Pavement Deflections for Network-level Analysis : Guide for Assessment of Pavement Structure Performance for PMS Applications

DOT National Transportation Integrated Search

2012-06-01

The objective of this study was to develop an approach for incorporating techniques to interpret and evaluate deflection : data for network-level pavement management system (PMS) applications. The first part of this research focused on : identifying ...

Simulation verification techniques study: Simulation performance validation techniques document. [for the space shuttle system

NASA Technical Reports Server (NTRS)

Duncan, L. M.; Reddell, J. P.; Schoonmaker, P. B.

1975-01-01

Techniques and support software for the efficient performance of simulation validation are discussed. Overall validation software structure, the performance of validation at various levels of simulation integration, guidelines for check case formulation, methods for real time acquisition and formatting of data from an all up operational simulator, and methods and criteria for comparison and evaluation of simulation data are included. Vehicle subsystems modules, module integration, special test requirements, and reference data formats are also described.

Assessment of metal artifact reduction methods in pelvic CT

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

Abdoli, Mehrsima; Mehranian, Abolfazl; Ailianou, Angeliki

2016-04-15

Purpose: Metal artifact reduction (MAR) produces images with improved quality potentially leading to confident and reliable clinical diagnosis and therapy planning. In this work, the authors evaluate the performance of five MAR techniques for the assessment of computed tomography images of patients with hip prostheses. Methods: Five MAR algorithms were evaluated using simulation and clinical studies. The algorithms included one-dimensional linear interpolation (LI) of the corrupted projection bins in the sinogram, two-dimensional interpolation (2D), a normalized metal artifact reduction (NMAR) technique, a metal deletion technique, and a maximum a posteriori completion (MAPC) approach. The algorithms were applied to ten simulatedmore » datasets as well as 30 clinical studies of patients with metallic hip implants. Qualitative evaluations were performed by two blinded experienced radiologists who ranked overall artifact severity and pelvic organ recognition for each algorithm by assigning scores from zero to five (zero indicating totally obscured organs with no structures identifiable and five indicating recognition with high confidence). Results: Simulation studies revealed that 2D, NMAR, and MAPC techniques performed almost equally well in all regions. LI falls behind the other approaches in terms of reducing dark streaking artifacts as well as preserving unaffected regions (p < 0.05). Visual assessment of clinical datasets revealed the superiority of NMAR and MAPC in the evaluated pelvic organs and in terms of overall image quality. Conclusions: Overall, all methods, except LI, performed equally well in artifact-free regions. Considering both clinical and simulation studies, 2D, NMAR, and MAPC seem to outperform the other techniques.« less

[Development of performance evaluation and management system on advanced schistosomiasis medical treatment].

PubMed

Zhou, Xiao-Rong; Huang, Shui-Sheng; Gong, Xin-Guo; Cen, Li-Ping; Zhang, Cong; Zhu, Hong; Yang, Jun-Jing; Chen, Li

2012-04-01

To construct a performance evaluation and management system on advanced schistosomiasis medical treatment, and analyze and evaluate the work of the advanced schistosomiasis medical treatment over the years. By applying the database management technique and C++ programming technique, we inputted the information of the advanced schistosomiasis cases into the system, and comprehensively evaluated the work of the advanced schistosomiasis medical treatment through the cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. We made a set of software formula about cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. This system had many features such as clear building, easy to operate, friendly surface, convenient information input and information search. It could benefit the performance evaluation of the province's advanced schistosomiasis medical treatment work. This system can satisfy the current needs of advanced schistosomiasis medical treatment work and can be easy to be widely used.

Performance Evaluation of Cognitive Interference Channels Using a Spectrum Overlay Strategy

NASA Technical Reports Server (NTRS)

Knoblock, Eric J.

2018-01-01

The use of cognitive radios (CR) and cooperative communications techniques may assist in interference mitigation via sensing of the environment and dynamically altering communications parameters through the use of various mechanisms - one of which is the overlay technique. This report provides a performance analysis of an interference channel with a cognitive transceiver operating in an overlay configuration to evaluate the gains from using cognition. As shown in this report, a cognitive transceiver can simultaneously share spectrum while enhancing performance of non-cognitive nodes via knowledge of the communications channel as well as knowledge of neighboring users' modulation and coding schemes.

Advanced smoke meter development survey and analysis

NASA Technical Reports Server (NTRS)

Pitz, R. W.; Penney, C. M.; Stanforth, C. M.; Shaffernocker, W. M.

1984-01-01

Ideal smoke meter characteristics are determined to provide a basis for evaluation of candidate systems. Five promising techniques are analyzed in detail to evaluate compilance with the practical smoke meter requirements. Four of the smoke measurement concepts are optical methods: Modulated Transmission (MODTRAN), Cross Beam Absorption Counter (CBAC), Laser Induced Incandescence (LIN), and Photoacoustic Spectroscopy (PAS). A rapid response filter instrument called a Taper Element Oscillating Microbalance (TEOM) is also evaluated. For each technique, the theoretical principles are described, the expected performance is determined, and the advantages and disadvantages are discussed The expected performance is evaluated against each of the smoke meter specifications, and the key questions for further study are given. The most promising smoke meter technique analyzed was MODTRAN, which is a variation on a direct transmission measurement. The soot-laden gas is passed through a transmission cell, and the gas pressure is modulated by a speaker.

Diversity in Teacher Assessment: What's Working, What's Not?

ERIC Educational Resources Information Center

Nweke, Winifred; Noland, Juanie

The purpose of this study was to evaluate the effectiveness of using performance and portfolio assessment techniques to diversify assessment in a minority teacher education program at Tuskegee University (Alabama). Both performance and portfolio assessments served as the exit examination. These techniques were used for three reasons: a state…

Vis-A-Plan /visualize a plan/ management technique provides performance-time scale

NASA Technical Reports Server (NTRS)

Ranck, N. H.

1967-01-01

Vis-A-Plan is a bar-charting technique for representing and evaluating project activities on a performance-time basis. This rectilinear method presents the logic diagram of a project as a series of horizontal time bars. It may be used supplementary to PERT or independently.

Hardware Demonstration: Frequency Spectra of Transients

NASA Technical Reports Server (NTRS)

McCloskey, John; Dimov, Jen

2017-01-01

Radiated emissions measurements as specified by MIL-STD-461 are performed in the frequency domain, which is best suited to continuous wave (CW) types of signals. However, many platforms implement signals that are single event pulses or transients. Such signals can potentially generate momentary radiated emissions that can cause interference in the system, but they may be missed with traditional measurement techniques. This demonstration provides measurement and analysis techniques that effectively evaluate the potential emissions from such signals in order to evaluate their potential impacts to system performance.

Evaluation of the performance, cost-effectiveness, and timing of various preventive maintenances : interim report.

DOT National Transportation Integrated Search

2010-10-01

This research study evaluated the performance of various pavement preservation treatments over time and under different : environmental conditions to quantify the economics of each treatment type. There are three primary techniques utilized in Colora...

Transverse vibration technique to identify deteriorated wood floor systems

Treesearch

R.J. Ross; X. Wang; M.O. Hunt; L.A. Soltis

2002-01-01

The Forest Products Laboratory, USDA Forest Service, has been developing nondestructive evaluation (NDE) techniques to identify degradation of wood in structures and the performance characteristics that remain in the structure. This work has focused on using dynamic testing techniques, particularly stress wave and ultrasonic transmission NDE techniques for both...

On Evaluating Brain Tissue Classifiers without a Ground Truth

PubMed Central

Martin-Fernandez, Marcos; Ungar, Lida; Nakamura, Motoaki; Koo, Min-Seong; McCarley, Robert W.; Shenton, Martha E.

2009-01-01

In this paper, we present a set of techniques for the evaluation of brain tissue classifiers on a large data set of MR images of the head. Due to the difficulty of establishing a gold standard for this type of data, we focus our attention on methods which do not require a ground truth, but instead rely on a common agreement principle. Three different techniques are presented: the Williams’ index, a measure of common agreement; STAPLE, an Expectation Maximization algorithm which simultaneously estimates performance parameters and constructs an estimated reference standard; and Multidimensional Scaling, a visualization technique to explore similarity data. We apply these different evaluation methodologies to a set eleven different segmentation algorithms on forty MR images. We then validate our evaluation pipeline by building a ground truth based on human expert tracings. The evaluations with and without a ground truth are compared. Our findings show that comparing classifiers without a gold standard can provide a lot of interesting information. In particular, outliers can be easily detected, strongly consistent or highly variable techniques can be readily discriminated, and the overall similarity between different techniques can be assessed. On the other hand, we also find that some information present in the expert segmentations is not captured by the automatic classifiers, suggesting that common agreement alone may not be sufficient for a precise performance evaluation of brain tissue classifiers. PMID:17532646

Using Personal Selling Techniques to Influence Student Evaluation of Faculty Instruction

ERIC Educational Resources Information Center

Adrian, C. Mitchell; Phelps, Lonnie D.; Totten, Jeffery W.

2017-01-01

Use of Student Evaluation of Instruction (SEI) in higher education was originally intended as a source of feedback to faculty, but it has developed into a significant part of faculty performance evaluations. Administrators supporting the use of SEI's as a performance indicator assume students recognize and reward "good teaching." It is…

Comparison of digital and conventional impression techniques: evaluation of patients' perception, treatment comfort, effectiveness and clinical outcomes.

PubMed

Yuzbasioglu, Emir; Kurt, Hanefi; Turunc, Rana; Bilir, Halenur

2014-01-30

The purpose of this study was to compare two impression techniques from the perspective of patient preferences and treatment comfort. Twenty-four (12 male, 12 female) subjects who had no previous experience with either conventional or digital impression participated in this study. Conventional impressions of maxillary and mandibular dental arches were taken with a polyether impression material (Impregum, 3 M ESPE), and bite registrations were made with polysiloxane bite registration material (Futar D, Kettenbach). Two weeks later, digital impressions and bite scans were performed using an intra-oral scanner (CEREC Omnicam, Sirona). Immediately after the impressions were made, the subjects' attitudes, preferences and perceptions towards impression techniques were evaluated using a standardized questionnaire. The perceived source of stress was evaluated using the State-Trait Anxiety Scale. Processing steps of the impression techniques (tray selection, working time etc.) were recorded in seconds. Statistical analyses were performed with the Wilcoxon Rank test, and p < 0.05 was considered significant. There were significant differences among the groups (p < 0.05) in terms of total working time and processing steps. Patients stated that digital impressions were more comfortable than conventional techniques. Digital impressions resulted in a more time-efficient technique than conventional impressions. Patients preferred the digital impression technique rather than conventional techniques.

CCD correlation techniques

NASA Technical Reports Server (NTRS)

Hewes, C. R.; Bosshart, P. W.; Eversole, W. L.; Dewit, M.; Buss, D. D.

1976-01-01

Two CCD techniques were discussed for performing an N-point sampled data correlation between an input signal and an electronically programmable reference function. The design and experimental performance of an implementation of the direct time correlator utilizing two analog CCDs and MOS multipliers on a single IC were evaluated. The performance of a CCD implementation of the chirp z transform was described, and the design of a new CCD integrated circuit for performing correlation by multiplication in the frequency domain was presented. This chip provides a discrete Fourier transform (DFT) or inverse DFT, multipliers, and complete support circuitry for the CCD CZT. The two correlation techniques are compared.

An Evaluation of Crack, Seat and Overlay in California (Phase II)

DOT National Transportation Integrated Search

2011-01-18

During the past 20 years hundreds of highway miles in California have been rehabilitated employing CS&O technique with little performance data : available. This study was conducted to evaluate the performance of CS&O for sections built in different c...

USING BIOASSAYS TO EVALUATE THE PERFORMANCE OF EDC RISK MANAGEMENT METHODS

EPA Science Inventory

In Superfund risk management research, the performance of risk management techniques is typically evaluated by measuring "the concentrations of the chemicals of concern before and after risk management efforts. However, using bioassays and chemical data provides a more robust und...

Quality Attribute Techniques Framework

NASA Astrophysics Data System (ADS)

Chiam, Yin Kia; Zhu, Liming; Staples, Mark

The quality of software is achieved during its development. Development teams use various techniques to investigate, evaluate and control potential quality problems in their systems. These “Quality Attribute Techniques” target specific product qualities such as safety or security. This paper proposes a framework to capture important characteristics of these techniques. The framework is intended to support process tailoring, by facilitating the selection of techniques for inclusion into process models that target specific product qualities. We use risk management as a theory to accommodate techniques for many product qualities and lifecycle phases. Safety techniques have motivated the framework, and safety and performance techniques have been used to evaluate the framework. The evaluation demonstrates the ability of quality risk management to cover the development lifecycle and to accommodate two different product qualities. We identify advantages and limitations of the framework, and discuss future research on the framework.

Evaluation of Classifier Performance for Multiclass Phenotype Discrimination in Untargeted Metabolomics.

PubMed

Trainor, Patrick J; DeFilippis, Andrew P; Rai, Shesh N

2017-06-21

Statistical classification is a critical component of utilizing metabolomics data for examining the molecular determinants of phenotypes. Despite this, a comprehensive and rigorous evaluation of the accuracy of classification techniques for phenotype discrimination given metabolomics data has not been conducted. We conducted such an evaluation using both simulated and real metabolomics datasets, comparing Partial Least Squares-Discriminant Analysis (PLS-DA), Sparse PLS-DA, Random Forests, Support Vector Machines (SVM), Artificial Neural Network, k -Nearest Neighbors ( k -NN), and Naïve Bayes classification techniques for discrimination. We evaluated the techniques on simulated data generated to mimic global untargeted metabolomics data by incorporating realistic block-wise correlation and partial correlation structures for mimicking the correlations and metabolite clustering generated by biological processes. Over the simulation studies, covariance structures, means, and effect sizes were stochastically varied to provide consistent estimates of classifier performance over a wide range of possible scenarios. The effects of the presence of non-normal error distributions, the introduction of biological and technical outliers, unbalanced phenotype allocation, missing values due to abundances below a limit of detection, and the effect of prior-significance filtering (dimension reduction) were evaluated via simulation. In each simulation, classifier parameters, such as the number of hidden nodes in a Neural Network, were optimized by cross-validation to minimize the probability of detecting spurious results due to poorly tuned classifiers. Classifier performance was then evaluated using real metabolomics datasets of varying sample medium, sample size, and experimental design. We report that in the most realistic simulation studies that incorporated non-normal error distributions, unbalanced phenotype allocation, outliers, missing values, and dimension reduction, classifier performance (least to greatest error) was ranked as follows: SVM, Random Forest, Naïve Bayes, sPLS-DA, Neural Networks, PLS-DA and k -NN classifiers. When non-normal error distributions were introduced, the performance of PLS-DA and k -NN classifiers deteriorated further relative to the remaining techniques. Over the real datasets, a trend of better performance of SVM and Random Forest classifier performance was observed.

Skylab program earth resources experiment package sensor performance evaluation, volume 1, (S190A)

NASA Technical Reports Server (NTRS)

Kenney, G. P.

1975-01-01

The results of S190A sensor performance evaluation are summarized based on data presented by all contributors to the sensor performance evaluation interim reports. Techniques used in sensor performance evaluation are discussed. Topics discussed include: performance degradation identified during the Skylab missions, S190A and EREP system anomalies that affected S190A performance, and the performance achieved, in terms of pertinent S190A parameters. Additional analyses include final performance analyses completed after submittal of the SL4 interim sensor performance evaluation reports, including completion of detailed analyses of basic performance parameters initiated during the interim report periods and consolidation analyses to reduce independent mission data (SL2, SL3, and SL4) to determine overall performance realized during all three Skylab missions.

Models and techniques for evaluating the effectiveness of aircraft computing systems

NASA Technical Reports Server (NTRS)

Meyer, J. F.

1978-01-01

The development of system models that can provide a basis for the formulation and evaluation of aircraft computer system effectiveness, the formulation of quantitative measures of system effectiveness, and the development of analytic and simulation techniques for evaluating the effectiveness of a proposed or existing aircraft computer are described. Specific topics covered include: system models; performability evaluation; capability and functional dependence; computation of trajectory set probabilities; and hierarchical modeling of an air transport mission.

Job Performance Aids: Research and Technology State-of-the-Art. Final Report.

ERIC Educational Resources Information Center

Booher, Harold R.

Conducted as part of a major effort to test and evaluate Job Performance Aids (JPA) and their integration with Navy personnel and training systems, this study systematically reviewed and organized existing JPA techniques, related research data, and various applicable principles and concepts. One hundred and one JPA systems and techniques were…

Double Density Dual Tree Discrete Wavelet Transform implementation for Degraded Image Enhancement

NASA Astrophysics Data System (ADS)

Vimala, C.; Aruna Priya, P.

2018-04-01

Wavelet transform is a main tool for image processing applications in modern existence. A Double Density Dual Tree Discrete Wavelet Transform is used and investigated for image denoising. Images are considered for the analysis and the performance is compared with discrete wavelet transform and the Double Density DWT. Peak Signal to Noise Ratio values and Root Means Square error are calculated in all the three wavelet techniques for denoised images and the performance has evaluated. The proposed techniques give the better performance when comparing other two wavelet techniques.

Comparative Analysis Between Computed and Conventional Inferior Alveolar Nerve Block Techniques.

PubMed

Araújo, Gabriela Madeira; Barbalho, Jimmy Charles Melo; Dias, Tasiana Guedes de Souza; Santos, Thiago de Santana; Vasconcellos, Ricardo José de Holanda; de Morais, Hécio Henrique Araújo

2015-11-01

The aim of this randomized, double-blind, controlled trial was to compare the computed and conventional inferior alveolar nerve block techniques in symmetrically positioned inferior third molars. Both computed and conventional anesthetic techniques were performed in 29 healthy patients (58 surgeries) aged between 18 and 40 years. The anesthetic of choice was 2% lidocaine with 1: 200,000 epinephrine. The Visual Analogue Scale assessed the pain variable after anesthetic infiltration. Patient satisfaction was evaluated using the Likert Scale. Heart and respiratory rates, mean time to perform technique, and the need for additional anesthesia were also evaluated. Pain variable means were higher for the conventional technique as compared with computed, 3.45 ± 2.73 and 2.86 ± 1.96, respectively, but no statistically significant differences were found (P > 0.05). Patient satisfaction showed no statistically significant differences. The average computed technique runtime and the conventional were 3.85 and 1.61 minutes, respectively, showing statistically significant differences (P <0.001). The computed anesthetic technique showed lower mean pain perception, but did not show statistically significant differences when contrasted to the conventional technique.

Assessment of masticatory performance by means of a color-changeable chewing gum.

PubMed

Tarkowska, Agnieszka; Katzer, Lukasz; Ahlers, Marcus Oliver

2017-01-01

Previous research determined the relevance of masticatory performance with regard to nutritional status, cognitive functions, or stress management. In addition, the measurement of masticatory efficiency contributes to the evaluation of therapeutic successes within the stomatognathic system. However, the question remains unanswered as to what extent modern techniques are able to reproduce the subtle differences in masticatory efficiency within various patient groups. The purpose of this review is to provide an extensive summary of the evaluation of masticatory performance by means of a color-changeable chewing gum with regard to its clinical relevance and applicability. A general overview describing the various methods available for this task has already been published. This review focuses in depth on the research findings available on the technique of measuring masticatory performance by means of color-changeable chewing gum. Described are the mechanism and the differentiability of the color change and methods to evaluate the color changes. Subsequently, research on masticatory performance is conducted with regard to patient age groups, the impact of general diseases and the effect of prosthetic and surgical treatment. The studies indicate that color-changeable chewing gum is a valid and reliable method for the evaluation of masticatory function. Apart from other methods, in clinical practice this technique can enhance dental diagnostics as well as the assessment of therapy outcomes. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Analytical Modelling of the Effects of Different Gas Turbine Cooling Techniques on Engine Performance =

NASA Astrophysics Data System (ADS)

Uysal, Selcuk Can

In this research, MATLAB SimulinkRTM was used to develop a cooled engine model for industrial gas turbines and aero-engines. The model consists of uncooled on-design, mean-line turbomachinery design and a cooled off-design analysis in order to evaluate the engine performance parameters by using operating conditions, polytropic efficiencies, material information and cooling system details. The cooling analysis algorithm involves a 2nd law analysis to calculate losses from the cooling technique applied. The model is used in a sensitivity analysis that evaluates the impacts of variations in metal Biot number, thermal barrier coating Biot number, film cooling effectiveness, internal cooling effectiveness and maximum allowable blade temperature on main engine performance parameters of aero and industrial gas turbine engines. The model is subsequently used to analyze the relative performance impact of employing Anti-Vortex Film Cooling holes (AVH) by means of data obtained for these holes by Detached Eddy Simulation-CFD Techniques that are valid for engine-like turbulence intensity conditions. Cooled blade configurations with AVH and other different external cooling techniques were used in a performance comparison study. (Abstract shortened by ProQuest.).

Ground penetrating radar evaluation and implementation.

DOT National Transportation Integrated Search

2014-07-01

Six commercial ground penetrating radar (GPR) : systems were evaluated to determine the state-of-the-art of GPR technologies for railroad track : substructure inspection. : Phase 1 evaluated GPR ballast inspection : techniques by performing testing a...

Design and performance evaluation of a dispersion compensation unit using several chirping functions in a tanh apodized FBG and comparison with dispersion compensation fiber.

PubMed

Mohammed, Nazmi A; Solaiman, Mohammad; Aly, Moustafa H

2014-10-10

In this work, various dispersion compensation methods are designed and evaluated to search for a cost-effective technique with remarkable dispersion compensation and a good pulse shape. The techniques consist of different chirp functions applied to a tanh fiber Bragg grating (FBG), a dispersion compensation fiber (DCF), and a DCF merged with an optimized linearly chirped tanh FBG (joint technique). The techniques are evaluated using a standard 10 Gb/s optical link over a 100 km long haul. The linear chirp function is the most appropriate choice of chirping function, with a pulse width reduction percentage (PWRP) of 75.15%, lower price, and poor pulse shape. The DCF yields an enhanced PWRP of 93.34% with a better pulse quality; however, it is the most costly of the evaluated techniques. Finally, the joint technique achieved the optimum PWRP (96.36%) among all the evaluated techniques and exhibited a remarkable pulse shape; it is less costly than the DCF, but more expensive than the chirped tanh FBG.

Parallel implementation and evaluation of motion estimation system algorithms on a distributed memory multiprocessor using knowledge based mappings

NASA Technical Reports Server (NTRS)

Choudhary, Alok Nidhi; Leung, Mun K.; Huang, Thomas S.; Patel, Janak H.

1989-01-01

Several techniques to perform static and dynamic load balancing techniques for vision systems are presented. These techniques are novel in the sense that they capture the computational requirements of a task by examining the data when it is produced. Furthermore, they can be applied to many vision systems because many algorithms in different systems are either the same, or have similar computational characteristics. These techniques are evaluated by applying them on a parallel implementation of the algorithms in a motion estimation system on a hypercube multiprocessor system. The motion estimation system consists of the following steps: (1) extraction of features; (2) stereo match of images in one time instant; (3) time match of images from different time instants; (4) stereo match to compute final unambiguous points; and (5) computation of motion parameters. It is shown that the performance gains when these data decomposition and load balancing techniques are used are significant and the overhead of using these techniques is minimal.

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...

The Effect of Conductor Expressivity on Ensemble Performance Evaluation

ERIC Educational Resources Information Center

Morrison, Steven J.; Price, Harry E.; Geiger, Carla G.; Cornacchio, Rachel A.

2009-01-01

In this study, the authors examined whether a conductor's use of high-expressivity or low-expressivity techniques affected evaluations of ensemble performances that were identical across conducting conditions. Two conductors each conducted two 1-minute parallel excerpts from Percy Grainger's "Walking Tune." Each directed one excerpt…

Longitudinal Joint Construction Techniques for Asphalt Pavements

DOT National Transportation Integrated Search

1997-08-01

Thirty hot mix asphalt (HMA) test sections were constructed in Michigan (1992), Wisconsin (1992), Colorado (1994), and Pennsylvania (1995) to evaluate the effectiveness of twelve different longitudinal joint construction techniques. The performance o...

Evaluation methodologies for an advanced information processing system

NASA Technical Reports Server (NTRS)

Schabowsky, R. S., Jr.; Gai, E.; Walker, B. K.; Lala, J. H.; Motyka, P.

1984-01-01

The system concept and requirements for an Advanced Information Processing System (AIPS) are briefly described, but the emphasis of this paper is on the evaluation methodologies being developed and utilized in the AIPS program. The evaluation tasks include hardware reliability, maintainability and availability, software reliability, performance, and performability. Hardware RMA and software reliability are addressed with Markov modeling techniques. The performance analysis for AIPS is based on queueing theory. Performability is a measure of merit which combines system reliability and performance measures. The probability laws of the performance measures are obtained from the Markov reliability models. Scalar functions of this law such as the mean and variance provide measures of merit in the AIPS performability evaluations.

Performance measurement for supply chain management and evaluation criteria determination for reverse supply chain management

NASA Astrophysics Data System (ADS)

Kongar, N. Elif

2004-12-01

Today, since customers are able to obtain similar-quality products for similar prices, the lead time has become the only preference criterion for most of the consumers. Therefore, it is crucial that the lead time, i.e., the time spent from the raw material phase till the manufactured good reaches the customer, is minimized. This issue can be investigated under the title of Supply Chain Management (SCM). An efficiently managed supply chain can lead to reduced response time for customers. To achieve this, continuous observation of supply chain efficiency, i.e., a constant performance evaluation of the current SCM is required. Widely used conventional performance measurement methods lack the ability to evaluate a SCM since the supply chain is a dynamic system that requires a more thorough and flexible performance measurement technique. Balanced Scorecard (BS) is an efficient tool for measuring the performance of dynamic systems and has a proven capability of providing the decision makers with the appropriate feedback data. In addition to SCM, a relatively new management field, namely reverse supply chain management (RSCM), also necessitates an appropriate evaluation approach. RSCM differs from SCM in many aspects, i.e., the criteria used for evaluation, the high level of uncertainty involved etc., not allowing the usage of identical evaluation techniques used for SCM. This study proposes a generic Balanced Scorecard to measure the performance of supply chain management while defining the appropriate performance measures for SCM. A scorecard prototype, ESCAPE, is presented to demonstrate the evaluation process.

Comparison of digital and conventional impression techniques: evaluation of patients’ perception, treatment comfort, effectiveness and clinical outcomes

PubMed Central

2014-01-01

Background The purpose of this study was to compare two impression techniques from the perspective of patient preferences and treatment comfort. Methods Twenty-four (12 male, 12 female) subjects who had no previous experience with either conventional or digital impression participated in this study. Conventional impressions of maxillary and mandibular dental arches were taken with a polyether impression material (Impregum, 3 M ESPE), and bite registrations were made with polysiloxane bite registration material (Futar D, Kettenbach). Two weeks later, digital impressions and bite scans were performed using an intra-oral scanner (CEREC Omnicam, Sirona). Immediately after the impressions were made, the subjects’ attitudes, preferences and perceptions towards impression techniques were evaluated using a standardized questionnaire. The perceived source of stress was evaluated using the State-Trait Anxiety Scale. Processing steps of the impression techniques (tray selection, working time etc.) were recorded in seconds. Statistical analyses were performed with the Wilcoxon Rank test, and p < 0.05 was considered significant. Results There were significant differences among the groups (p < 0.05) in terms of total working time and processing steps. Patients stated that digital impressions were more comfortable than conventional techniques. Conclusions Digital impressions resulted in a more time-efficient technique than conventional impressions. Patients preferred the digital impression technique rather than conventional techniques. PMID:24479892

Non-destructive Analysis Reveals Effect of Installation Details on Plywood Siding Performance

Treesearch

Christopher G. Hunt; Gregory T. Schueneman; Steven Lacher; Xiping Wang; R. Sam Williams

2015-01-01

This study evaluated the influence of a variety of construction techniques on the performance of plywood siding and the applied paint, using both ultrasound and conventional visual inspection techniques. The impact of bottom edge contact, flashing vs. caulking board ends, priming the bottom edge, location (Wisconsin vs. Mississippi) and a gap behind the siding to...

A systematic review on the quality of measurement techniques for the assessment of burn wound depth or healing potential.

PubMed

Jaspers, Mariëlle E H; van Haasterecht, Ludo; van Zuijlen, Paul P M; Mokkink, Lidwine B

2018-06-22

Reliable and valid assessment of burn wound depth or healing potential is essential to treatment decision-making, to provide a prognosis, and to compare studies evaluating different treatment modalities. The aim of this review was to critically appraise, compare and summarize the quality of relevant measurement properties of techniques that aim to assess burn wound depth or healing potential. A systematic literature search was performed using PubMed, EMBASE and Cochrane Library. Two reviewers independently evaluated the methodological quality of included articles using an adapted version of the Consensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. A synthesis of evidence was performed to rate the measurement properties for each technique and to draw an overall conclusion on quality of the techniques. Thirty-six articles were included, evaluating various techniques, classified as (1) laser Doppler techniques; (2) thermography or thermal imaging; (3) other measurement techniques. Strong evidence was found for adequate construct validity of laser Doppler imaging (LDI). Moderate evidence was found for adequate construct validity of thermography, videomicroscopy, and spatial frequency domain imaging (SFDI). Only two studies reported on the measurement property reliability. Furthermore, considerable variation was observed among comparator instruments. Considering the evidence available, it appears that LDI is currently the most favorable technique; thereby assessing burn wound healing potential. Additional research is needed into thermography, videomicroscopy, and SFDI to evaluate their full potential. Future studies should focus on reliability and measurement error, and provide a precise description of which construct is aimed to measure. Copyright © 2018 Elsevier Ltd and ISBI. All rights reserved.

Electrochemical impedance spectroscopy (EIS) as a tool for measuring corrosion of polymer-coated fasteners used in treated wood

Treesearch

Samuel L. Zelinka; Lorraine Ortiz-Candelaria; Donald S. Stone; Douglas R. Rammer

2009-01-01

Currently, many of the polymer-coated fasteners on the market are designed for improved corrosion performance in treated wood; yet, there is no way to evaluate their corrosion performance. In this study, a common technique for measuring the corrosion performance of polymer-coated metals, electrochemical impedance spectroscopy (EIS), was used to evaluate commercial...

Use of the Marshall Space Flight Center solar simulator in collector performance evaluation

NASA Technical Reports Server (NTRS)

Humphries, W. R.

1978-01-01

Actual measured values from simulator checkout tests are detailed. Problems encountered during initial startup are discussed and solutions described. Techniques utilized to evaluate collector performance from simulator test data are given. Performance data generated in the simulator are compared to equivalent data generated during natural outdoor testing. Finally, a summary of collector performance parameters generated to date as a result of simulator testing are given.

An Evaluation of shore-based radio direction finding

DOT National Transportation Integrated Search

1978-09-30

This report describes an evaluation of Radio Direction Finding (RDF) techniques for shore-based position location performed by the Transportation Systems Center (TSC). The evaluation consisted of the following three phases: (1) A preliminary survey t...

New Techniques to Evaluate the Incendiary Behavior of Insulators

NASA Technical Reports Server (NTRS)

Buhler, Charles; Calle, Carlos; Clements, Sid; Trigwell, Steve; Ritz, Mindy

2008-01-01

New techniques for evaluating the incendiary behavior of insulators is presented. The onset of incendive brush discharges in air is evaluated using standard spark probe techniques for the case simulating approaches of an electrically grounded sphere to a charged insulator in the presence of a flammable atmosphere. However, this standard technique is unsuitable for the case of brush discharges that may occur during the charging-separation process for two insulator materials. We present experimental techniques to evaluate this hazard in the presence of a flammable atmosphere which is ideally suited to measure the incendiary nature of micro-discharges upon separation, a measurement never before performed. Other measurement techniques unique to this study include; surface potential measurements of insulators before, during and after contact and separation, as well as methods to verify fieldmeter calibrations using a charge insulator surface opposed to standard high voltage plates. Key words: Kapton polyimide film, incendiary discharges, brush discharges, contact and frictional electrification, ignition hazards, insulators, contact angle, surface potential measurements.

Application and use of spinal immobilization devices in zero-gravity flight

NASA Technical Reports Server (NTRS)

Krupa, Debra T.; Gosbee, John; Billica, Roger; Boyce, Joey B.

1991-01-01

A KC-135 parabolic flight was performed for the purpose of evaluation of spinal immobilization techniques in microgravity. The flight followed the standard 40 parabola profile with four NASA/KRUG experimenters involved. One performed as coordinator/recorder, one as test subject, and two as the Crew Medical Officers (CMO). The flight was to evaluate the application of spinal immobilization devices and techniques in microgravity as are performed during initial stabilization or patient transport scenarios. The sequence of detail for examination of the following objectives included: attempted cervical spine immobilization with all free floating, the patient restrained to the floor, various hand positioning techniques; c-collar placement; Kendrick Extrication Device (KED) application with various restraints for patient and CMO; patient immobilization and transport using the KED; patient transported on KED and spine board. Observations for each task are included. Major conclusions and issues are also included.

Validation of motion correction techniques for liver CT perfusion studies

PubMed Central

Chandler, A; Wei, W; Anderson, E F; Herron, D H; Ye, Z; Ng, C S

2012-01-01

Objectives Motion in images potentially compromises the evaluation of temporally acquired CT perfusion (CTp) data; image registration should mitigate this, but first requires validation. Our objective was to compare the relative performance of manual, rigid and non-rigid registration techniques to correct anatomical misalignment in acquired liver CTp data sets. Methods 17 data sets in patients with liver tumours who had undergone a CTp protocol were evaluated. Each data set consisted of a cine acquisition during a breath-hold (Phase 1), followed by six further sets of cine scans (each containing 11 images) acquired during free breathing (Phase 2). Phase 2 images were registered to a reference image from Phase 1 cine using two semi-automated intensity-based registration techniques (rigid and non-rigid) and a manual technique (the only option available in the relevant vendor CTp software). The performance of each technique to align liver anatomy was assessed by four observers, independently and blindly, on two separate occasions, using a semi-quantitative visual validation study (employing a six-point score). The registration techniques were statistically compared using an ordinal probit regression model. Results 306 registrations (2448 observer scores) were evaluated. The three registration techniques were significantly different from each other (p=0.03). On pairwise comparison, the semi-automated techniques were significantly superior to the manual technique, with non-rigid significantly superior to rigid (p<0.0001), which in turn was significantly superior to manual registration (p=0.04). Conclusion Semi-automated registration techniques achieved superior alignment of liver anatomy compared with the manual technique. We hope this will translate into more reliable CTp analyses. PMID:22374283

Wide Panel Testing Technique for Evaluating Repair Weld Strengths

NASA Technical Reports Server (NTRS)

Rogers, Patrick R.; Bynum, Julian E.; Shah, Sandeep R.

1998-01-01

This paper describes a new tensile testing technique for evaluating the overall effect of a repair weld on the strength of a welded joint. Previously, repair weld strengths have been evaluated using one-inch width tensile specimens, but this technique does not capture all of the effects that result from a repair. The new technique involves testing of "wide panel" tensile specimens which contain the full length of a repair weld within a longer initial weld, allowing the specimen to capture the combined effects of residual stresses, local strength degradation, and load redistribution around a repair. The development of strains in the repair area of standard aluminum alloy specimens and new high-performance aluminum-lithium alloy specimens was observed and evaluated using photoelastic material. The results of this evaluation show an increased sensitivity to repair welding residual stresses in the aluminum-lithium alloy specimens.

Evaluation of velocity-sensitized and acceleration-sensitized NCE-MRA for below-knee peripheral arterial disease.

PubMed

Shaida, Nadeem; Priest, Andrew N; See, T C; Winterbottom, Andrew P; Graves, Martin J; Lomas, David J

2017-06-01

To evaluate the diagnostic performance of velocity- and acceleration-sensitized noncontrast-enhanced magnetic resonance angiography (NCE-MRA) of the infrageniculate arteries using contrast-enhanced MRA (CE-MRA) as a reference standard. Twenty-four patients with symptoms of peripheral arterial disease were recruited. Each patient's infrageniculate arterial tree was examined using a velocity-dependent flow-sensitized dephasing (VEL-FSD) technique, an acceleration-dependent (ACC-FSD) technique, and our conventional CE-MRA technique performed at 1.5T. The images were independently reviewed by two experienced vascular radiologists, who evaluated each vessel segment to assess visibility, diagnostic confidence, venous contamination, and detection of pathology. In all, 432 segments were evaluated by each of the three techniques by each reader in total. Overall diagnostic confidence was rated as moderate or high in 98.5% of segments with CE-MRA, 92.1% with VEL-FSD, and 79.9% with ACC-FSD. No venous contamination was seen in 96% of segments with CE-MRA, 72.2% with VEL-FSD, and 85.8% with ACC-FSD. Per-segment, per-limb, and per-patient sensitivities for detecting significant stenotic disease were 63.4%, 73%, and 92%, respectively, for ACC-FSD, and 65.3%, 87.2%, and 96% for VEL-FSD, and as such no significant statistical change was detected using McNemar's chi-squared test with P-values of 1.00, 0.13, and 0.77 obtained, respectively. Flow-dependent NCE-MRA techniques may have a role to play in evaluation of patients with peripheral vascular disease. Increased sensitivity of a velocity-based technique compared to an acceleration-based technique comes at the expense of greater venous contamination. 2J. Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1846-1853. © 2016 International Society for Magnetic Resonance in Medicine.

Evaluation of cardiopulmonary resuscitation techniques in microgravity

NASA Technical Reports Server (NTRS)

Billica, Roger; Gosbee, John; Krupa, Debra T.

1991-01-01

Cardiopulmonary resuscitation (CPR) techniques were investigated in microgravity with specific application to planned medical capabilities for Space Station Freedom (SSF). A KC-135 parabolic flight test was performed with the goal of evaluating and quantifying the efficacy of different types of microgravity CPR techniques. The flight followed the standard 40 parabola profile with 20 to 25 seconds of near-zero gravity in each parabola. Three experiments were involved chosen for their clinical background, certification, and practical experience in prior KC-135 parabolic flight. The CPR evaluation was performed using a standard training mannequin (recording resusci-Annie) which was used in practice prior to the actual flight. Aboard the KC-135, the prototype medical restraint system (MRS) for the SSF Health Maintenance Facility (HMF) was used for part of the study. Standard patient and crew restraints were used for interface with the MRS. During the portion of study where CPR was performed without MRS, a set of straps for crew restraint similar to those currently employed for the Space Shuttle program were used. The entire study was recorded via still camera and video.

UNIX-based operating systems robustness evaluation

NASA Technical Reports Server (NTRS)

Chang, Yu-Ming

1996-01-01

Robust operating systems are required for reliable computing. Techniques for robustness evaluation of operating systems not only enhance the understanding of the reliability of computer systems, but also provide valuable feed- back to system designers. This thesis presents results from robustness evaluation experiments on five UNIX-based operating systems, which include Digital Equipment's OSF/l, Hewlett Packard's HP-UX, Sun Microsystems' Solaris and SunOS, and Silicon Graphics' IRIX. Three sets of experiments were performed. The methodology for evaluation tested (1) the exception handling mechanism, (2) system resource management, and (3) system capacity under high workload stress. An exception generator was used to evaluate the exception handling mechanism of the operating systems. Results included exit status of the exception generator and the system state. Resource management techniques used by individual operating systems were tested using programs designed to usurp system resources such as physical memory and process slots. Finally, the workload stress testing evaluated the effect of the workload on system performance by running a synthetic workload and recording the response time of local and remote user requests. Moderate to severe performance degradations were observed on the systems under stress.

Application of pattern recognition techniques to crime analysis

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

Bender, C.F.; Cox, L.A. Jr.; Chappell, G.A.

1976-08-15

The initial goal was to evaluate the capabilities of current pattern recognition techniques when applied to existing computerized crime data. Performance was to be evaluated both in terms of the system's capability to predict crimes and to optimize police manpower allocation. A relation was sought to predict the crime's susceptibility to solution, based on knowledge of the crime type, location, time, etc. The preliminary results of this work are discussed. They indicate that automatic crime analysis involving pattern recognition techniques is feasible, and that efforts to determine optimum variables and techniques are warranted. 47 figures (RWR)

Quantitative magnetic resonance (MR) neurography for evaluation of peripheral nerves and plexus injuries

PubMed Central

Barousse, Rafael; Socolovsky, Mariano; Luna, Antonio

2017-01-01

Traumatic conditions of peripheral nerves and plexus have been classically evaluated by morphological imaging techniques and electrophysiological tests. New magnetic resonance imaging (MRI) studies based on 3D fat-suppressed techniques are providing high accuracy for peripheral nerve injury evaluation from a qualitative point of view. However, these techniques do not provide quantitative information. Diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) are functional MRI techniques that are able to evaluate and quantify the movement of water molecules within different biological structures. These techniques have been successfully applied in other anatomical areas, especially in the assessment of central nervous system, and now are being imported, with promising results for peripheral nerve and plexus evaluation. DWI and DTI allow performing a qualitative and quantitative peripheral nerve analysis, providing valuable pathophysiological information about functional integrity of these structures. In the field of trauma and peripheral nerve or plexus injury, several derived parameters from DWI and DTI studies such as apparent diffusion coefficient (ADC) or fractional anisotropy (FA) among others, can be used as potential biomarkers of neural damage providing information about fiber organization, axonal flow or myelin integrity. A proper knowledge of physical basis of these techniques and their limitations is important for an optimal interpretation of the imaging findings and derived data. In this paper, a comprehensive review of the potential applications of DWI and DTI neurographic studies is performed with a focus on traumatic conditions, including main nerve entrapment syndromes in both peripheral nerves and brachial or lumbar plexus. PMID:28932698

Implementation and evaluation of shared-memory communication and synchronization operations in MPICH2 using the Nemesis communication subsystem.

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

Buntinas, D.; Mercier, G.; Gropp, W.

2007-09-01

This paper presents the implementation of MPICH2 over the Nemesis communication subsystem and the evaluation of its shared-memory performance. We describe design issues as well as some of the optimization techniques we employed. We conducted a performance evaluation over shared memory using microbenchmarks. The evaluation shows that MPICH2 Nemesis has very low communication overhead, making it suitable for smaller-grained applications.

Support Vector Machine Based on Adaptive Acceleration Particle Swarm Optimization

PubMed Central

Abdulameer, Mohammed Hasan; Othman, Zulaiha Ali

2014-01-01

Existing face recognition methods utilize particle swarm optimizer (PSO) and opposition based particle swarm optimizer (OPSO) to optimize the parameters of SVM. However, the utilization of random values in the velocity calculation decreases the performance of these techniques; that is, during the velocity computation, we normally use random values for the acceleration coefficients and this creates randomness in the solution. To address this problem, an adaptive acceleration particle swarm optimization (AAPSO) technique is proposed. To evaluate our proposed method, we employ both face and iris recognition based on AAPSO with SVM (AAPSO-SVM). In the face and iris recognition systems, performance is evaluated using two human face databases, YALE and CASIA, and the UBiris dataset. In this method, we initially perform feature extraction and then recognition on the extracted features. In the recognition process, the extracted features are used for SVM training and testing. During the training and testing, the SVM parameters are optimized with the AAPSO technique, and in AAPSO, the acceleration coefficients are computed using the particle fitness values. The parameters in SVM, which are optimized by AAPSO, perform efficiently for both face and iris recognition. A comparative analysis between our proposed AAPSO-SVM and the PSO-SVM technique is presented. PMID:24790584

On the performance evaluation of LQAM-MPPM techniques over exponentiated Weibull fading free-space optical channels

NASA Astrophysics Data System (ADS)

Khallaf, Haitham S.; Elfiqi, Abdulaziz E.; Shalaby, Hossam M. H.; Sampei, Seiichi; Obayya, Salah S. A.

2018-06-01

We investigate the performance of hybrid L-ary quadrature-amplitude modulation-multi-pulse pulse-position modulation (LQAM-MPPM) techniques over exponentiated Weibull (EW) fading free-space optical (FSO) channel, considering both weather and pointing-error effects. Upper bound and approximate-tight upper bound expressions for the bit-error rate (BER) of LQAM-MPPM techniques over EW FSO channels are obtained, taking into account the effects of fog, beam divergence, and pointing-error. Setup block diagram for both the transmitter and receiver of the LQAM-MPPM/FSO system are introduced and illustrated. The BER expressions are evaluated numerically and the results reveal that LQAM-MPPM technique outperforms ordinary LQAM and MPPM schemes under different fading levels and weather conditions. Furthermore, the effect of modulation-index is investigated and it turned out that a modulation-index greater than 0.4 is required in order to optimize the system performance. Finally, the effect of pointing-error introduces a great power penalty on the LQAM-MPPM system performance. Specifically, at a BER of 10-9, pointing-error introduces power penalties of about 45 and 28 dB for receiver aperture sizes of DR = 50 and 200 mm, respectively.

Hyperspectral face recognition with spatiospectral information fusion and PLS regression.

PubMed

Uzair, Muhammad; Mahmood, Arif; Mian, Ajmal

2015-03-01

Hyperspectral imaging offers new opportunities for face recognition via improved discrimination along the spectral dimension. However, it poses new challenges, including low signal-to-noise ratio, interband misalignment, and high data dimensionality. Due to these challenges, the literature on hyperspectral face recognition is not only sparse but is limited to ad hoc dimensionality reduction techniques and lacks comprehensive evaluation. We propose a hyperspectral face recognition algorithm using a spatiospectral covariance for band fusion and partial least square regression for classification. Moreover, we extend 13 existing face recognition techniques, for the first time, to perform hyperspectral face recognition.We formulate hyperspectral face recognition as an image-set classification problem and evaluate the performance of seven state-of-the-art image-set classification techniques. We also test six state-of-the-art grayscale and RGB (color) face recognition algorithms after applying fusion techniques on hyperspectral images. Comparison with the 13 extended and five existing hyperspectral face recognition techniques on three standard data sets show that the proposed algorithm outperforms all by a significant margin. Finally, we perform band selection experiments to find the most discriminative bands in the visible and near infrared response spectrum.

Comparative study of shear wave-based elastography techniques in optical coherence tomography

NASA Astrophysics Data System (ADS)

Zvietcovich, Fernando; Rolland, Jannick P.; Yao, Jianing; Meemon, Panomsak; Parker, Kevin J.

2017-03-01

We compare five optical coherence elastography techniques able to estimate the shear speed of waves generated by one and two sources of excitation. The first two techniques make use of one piezoelectric actuator in order to produce a continuous shear wave propagation or a tone-burst propagation (TBP) of 400 Hz over a gelatin tissue-mimicking phantom. The remaining techniques utilize a second actuator located on the opposite side of the region of interest in order to create three types of interference patterns: crawling waves, swept crawling waves, and standing waves, depending on the selection of the frequency difference between the two actuators. We evaluated accuracy, contrast to noise ratio, resolution, and acquisition time for each technique during experiments. Numerical simulations were also performed in order to support the experimental findings. Results suggest that in the presence of strong internal reflections, single source methods are more accurate and less variable when compared to the two-actuator methods. In particular, TBP reports the best performance with an accuracy error <4.1%. Finally, the TBP was tested in a fresh chicken tibialis anterior muscle with a localized thermally ablated lesion in order to evaluate its performance in biological tissue.

Laparoscopic cholecystectomy poses physical injury risk to surgeons: analysis of hand technique and standing position.

PubMed

Youssef, Yassar; Lee, Gyusung; Godinez, Carlos; Sutton, Erica; Klein, Rosemary V; George, Ivan M; Seagull, F Jacob; Park, Adrian

2011-07-01

This study compares surgical techniques and surgeon's standing position during laparoscopic cholecystectomy (LC), investigating each with respect to surgeons' learning, performance, and ergonomics. Little homogeneity exists in LC performance and training. Variations in standing position (side-standing technique vs. between-standing technique) and hand technique (one-handed vs. two-handed) exist. Thirty-two LC procedures performed on a virtual reality simulator were video-recorded and analyzed. Each subject performed four different procedures: one-handed/side-standing, one-handed/between-standing, two-handed/side-standing, and two-handed/between-standing. Physical ergonomics were evaluated using Rapid Upper Limb Assessment (RULA). Mental workload assessment was acquired with the National Aeronautics and Space Administration-Task Load Index (NASA-TLX). Virtual reality (VR) simulator-generated performance evaluation and a subjective survey were analyzed. RULA scores were consistently lower (indicating better ergonomics) for the between-standing technique and higher (indicating worse ergonomics) for the side-standing technique, regardless of whether one- or two-handed. Anatomical scores overall showed side-standing to have a detrimental effect on the upper arms and trunk. The NASA-TLX showed significant association between the side-standing position and high physical demand, effort, and frustration (p<0.05). The two-handed technique in the side-standing position required more effort than the one-handed (p<0.05). No difference in operative time or complication rate was demonstrated among the four procedures. The two-handed/between-standing method was chosen as the best procedure to teach and standardize. Laparoscopic cholecystectomy poses a risk of physical injury to the surgeon. As LC is currently commonly performed in the United States, the left side-standing position may lead to increased physical demand and effort, resulting in ergonomically unsound conditions for the surgeon. Though further investigations should be conducted, adopting the between-standing position deserves serious consideration as it may be the best short-term ergonomic alternative.

Practice patterns of lymph-node mapping and sentinel-node biopsy for breast cancer in British Columbia.

PubMed

Chua, Boon; Olivotto, Ivo A; Donald, James C; Hayashi, Allen H; Davis, Noelle; Rusnak, Conrad H

2003-08-01

Because there is no standardized technique for mapping of lymph nodes and no optimal technique for evaluating the sentinel node, we decided to evaluate practice patterns for sentinel-node biopsy (SNB) for breast cancer in British Columbia 5 years after its introduction in 1996. We carried out mail and telephone surveys of general surgeons performing at least 1 SNB (n = 28) or not performing SNB (n = 50), and carried out telephone surveys or on-site visits with pathologists (n = 7) and nuclear medicine physicians (n = 5) from institutions supporting SNB in the province. We collected data on training, perceived indications and techniques for the surgical, imaging and pathologic assessments of SNB to obtain data on practice patterns in 2001 and the degree of consistency among surgeons and institutions involved in performing SNB and reasons for not adopting the SNB technique. By 2001, SNB was incorporated into the practice of 19% of surgeons (28 of 150) performing breast cancer surgery in British Columbia. The survey response rate among SNB surgeons was 89% (25 of 28). Twelve (48%) of the 25 surgeons implemented SNB in the context of a validation study. Ten (40%) of the 25 had no data management support to monitor their results. Surgical training included intraoperative mentoring alone (48%), formal training courses alone (20%), both (24%) and self-teaching (8%). One-third of the surgeons had performed fewer than 10 procedures. Five surgeons had abandoned routine axillary dissection. There was considerable variation regarding the indications for SNB, definition of a sentinel node and surgical techniques. All nuclear medicine departments had a written lymphatic mapping protocol, but each used a different volume and activity of radiotracer. Immunohistochemical evaluation of the sentinel nodes was performed at just 3 pathology laboratories. The survey response rate from surgeons not practising SNB was 54% (27 of 50). Among 24 responders in active practice, 7 (29%) planned to perform SNB; 79% had not decided on the SNB indications. Lack of operating room time was a major limiting factor. There was considerable variation in the surgical, nuclear medicine and pathology techniques for SNB in the absence of a planned approach for its implementation in British Columbia. Developing consensus around written guidelines for the indications and techniques of SNB may reduce this variation.

Quasi-optical grids with thin rectangular patch/aperture elements

NASA Technical Reports Server (NTRS)

Wu, Te-Kao

1993-01-01

Theoretical analysis is presented for an efficient and accurate performance evaluation of quasi-optical grids comprised of thin rectangular patch/aperture elements with/without a dielectric substrate/superstrate. The convergence rate of this efficient technique is improved by an order of magnitude with the approximate edge conditions incorporated in the basis functions of the integral equation solution. Also presented are the interesting applications of this efficient analytical technique to the design and performance evaluation of the coupling grids and beam splitters in the optical systems as well as thermal protection sunshields used in the communication systems of satellites and spacecrafts.

3RIP Evaluation of the Performance of the Search System Using a Realtime Simulation Technique.

ERIC Educational Resources Information Center

Lofstrom, Mats

This report describes a real-time simulation experiment to evaluate the performance of the search and editing system 3RIP, an interactive system written in the language BLISS on a DEC-10 computer. The test vehicle, preliminary test runs, and capacity test are detailed, and the following conclusions are reported: (1) 3RIP performs well up to the…

PERFORMANCE EVALUATION OF AN INNOVATIVE FIBER REINFORCED GEOPOLYMER SPRAY-APPLIED MORTAR FOR LARGE DIAMETER WASTEWATER MAIN REHABILITATION IN HOUSTON, TX

EPA Science Inventory

This report describes the performance evaluation of a fiber reinforced geopolymer spray-applied mortar, which has potential as a structural alternative to traditional open cut techniques used in large-diameter sewer pipes. Geopolymer is a sustainable green material that incorpor...

Mobile Formative Assessment Tool Based on Data Mining Techniques for Supporting Web-Based Learning

ERIC Educational Resources Information Center

Chen, Chih-Ming; Chen, Ming-Chuan

2009-01-01

Current trends clearly indicate that online learning has become an important learning mode. However, no effective assessment mechanism for learning performance yet exists for e-learning systems. Learning performance assessment aims to evaluate what learners learned during the learning process. Traditional summative evaluation only considers final…

Development and evaluation of a technique for in vivo monitoring of 60Co in human lungs

NASA Astrophysics Data System (ADS)

de Mello, J. Q.; Lucena, E. A.; Dantas, A. L. A.; Dantas, B. M.

2016-07-01

60Co is a fission product of 235U and represents a risk of internal exposure of workers in nuclear power plants, especially those involved in the maintenance of potentially contaminated parts and equipment. The control of 60Co intake by inhalation can be performed through in vivo monitoring. This work describes the evaluation of a technique through the minimum detectable activity and the corresponding minimum detectable effective doses, based on biokinetic and dosimetric models of 60Co in the human body. The results allow to state that the technique is suitable either for monitoring of occupational exposures or evaluation of accidental intake.

Skylab program earth resouces experiment package. Volume 4: Sensor performance evaluation (S193 R/S). [radiometer/scatterometer

NASA Technical Reports Server (NTRS)

Kenney, G. P.

1975-01-01

The results of the sensor performance evaluation of the 13.9 GHz radiometer/scatterometer, which was part of the earth resources experiment package on Skylab. Findings are presented in the areas of housekeeping parameters, antenna gain and scanning performance, dynamic range, linearity, precision, resolution, stability, integration time, and transmitter output. Supplementary analyses covering performance anomalies, data stream peculiarities, aircraft sensor data comparisons, scatterometer saturation characteristics, and RF heating effects are reported. Results of the evaluation show that instrument performance was generally as expected, but capability degradations were observed to result from three major anomalies. Conclusions are drawn from the evaluation results, and recommendations for improving the effectiveness of a future program are offered. An addendum describes the special evaluation techniques developed and applied in the sensor performance evaluation tasks.

Psychophysical evaluation of the image quality of a dynamic flat-panel digital x-ray image detector using the threshold contrast detail detectability (TCDD) technique

NASA Astrophysics Data System (ADS)

Davies, Andrew G.; Cowen, Arnold R.; Bruijns, Tom J. C.

1999-05-01

We are currently in an era of active development of the digital X-ray imaging detectors that will serve the radiological communities in the new millennium. The rigorous comparative physical evaluations of such devices are therefore becoming increasingly important from both the technical and clinical perspectives. The authors have been actively involved in the evaluation of a clinical demonstration version of a flat-panel dynamic digital X-ray image detector (or FDXD). Results of objective physical evaluation of this device have been presented elsewhere at this conference. The imaging performance of FDXD under radiographic exposure conditions have been previously reported, and in this paper a psychophysical evaluation of the FDXD detector operating under continuous fluoroscopic conditions is presented. The evaluation technique employed was the threshold contrast detail detectability (TCDD) technique, which enables image quality to be measured on devices operating in the clinical environment. This approach addresses image quality in the context of both the image acquisition and display processes, and uses human observers to measure performance. The Leeds test objects TO[10] and TO[10+] were used to obtain comparative measurements of performance on the FDXD and two digital spot fluorography (DSF) systems, one utilizing a Plumbicon camera and the other a state of the art CCD camera. Measurements were taken at a range of detector entrance exposure rates, namely 6, 12, 25 and 50 (mu) R/s. In order to facilitate comparisons between the systems, all fluoroscopic image processing such as noise reduction algorithms, were disabled during the experiments. At the highest dose rate FDXD significantly outperformed the DSF comparison systems in the TCDD comparisons. At 25 and 12 (mu) R/s all three-systems performed in an equivalent manner and at the lowest exposure rate FDXD was inferior to the two DSF systems. At standard fluoroscopic exposures, FDXD performed in an equivalent manner to the DSF systems for the TCDD comparisons. This would suggest that FDXD would therefore perform adequately in a clinical fluoroscopic environment and our initial clinical experiences support this. Noise reduction processing of the fluoroscopic data acquired on FDXD was also found to further improve TCDD performance for FDXD. FDXD therefore combines acceptable fluoroscopic performance with excellent radiographic (snap shot) imaging fidelity, allowing the possibility of a universal x-ray detector to be developed, based on FDXD's technology. It is also envisaged that fluoroscopic performance will be improved by the development of digital image enhancement techniques specifically tailored to the characteristics of the FDXD detector.

Models and techniques for evaluating the effectiveness of aircraft computing systems

NASA Technical Reports Server (NTRS)

Meyer, J. F.

1982-01-01

Models, measures, and techniques for evaluating the effectiveness of aircraft computing systems were developed. By "effectiveness" in this context we mean the extent to which the user, i.e., a commercial air carrier, may expect to benefit from the computational tasks accomplished by a computing system in the environment of an advanced commercial aircraft. Thus, the concept of effectiveness involves aspects of system performance, reliability, and worth (value, benefit) which are appropriately integrated in the process of evaluating system effectiveness. Specifically, the primary objectives are: the development of system models that provide a basis for the formulation and evaluation of aircraft computer system effectiveness, the formulation of quantitative measures of system effectiveness, and the development of analytic and simulation techniques for evaluating the effectiveness of a proposed or existing aircraft computer.

Girls' soccer performance and motivation: games vs technique approach.

PubMed

Chatzopoulos, Dimitris; Drakou, Amalia; Kotzamanidou, Marina; Tsorbatzoudis, Haralambos

2006-10-01

The purpose of this study was to investigate the effects of the Technique and Games approaches on girls' soccer performance and motivation. The Technique approach focuses on technique instruction using drills, whereas the Games approach places emphasis on tactic instruction with modified games. 37 girls, 12 to 13 years old, were taught 15 soccer lessons by the Technique approach and 35 girls by the Games approach. At the beginning and at the end of the research soccer matches were videotaped and evaluated by Oslin, Mitchell, and Griffin's Game Performance Assessment Instrument. Girls' motivation was assessed on the Intrinsic Motivation Inventory. The Games group had significantly better scores after training on tactical behaviour and intrinsic motivation than the Technique group. There were no significant differences in skill execution between groups trained under the two approaches. Considering the importance of intrinsic motivation for a lifelong, physically active lifestyle, researchers could focus study on the approaches and girls' motivation.

Practical Framework for an Electron Beam Induced Current Technique Based on a Numerical Optimization Approach

NASA Astrophysics Data System (ADS)

Yamaguchi, Hideshi; Soeda, Takeshi

2015-03-01

A practical framework for an electron beam induced current (EBIC) technique has been established for conductive materials based on a numerical optimization approach. Although the conventional EBIC technique is useful for evaluating the distributions of dopants or crystal defects in semiconductor transistors, issues related to the reproducibility and quantitative capability of measurements using this technique persist. For instance, it is difficult to acquire high-quality EBIC images throughout continuous tests due to variation in operator skill or test environment. Recently, due to the evaluation of EBIC equipment performance and the numerical optimization of equipment items, the constant acquisition of high contrast images has become possible, improving the reproducibility as well as yield regardless of operator skill or test environment. The technique proposed herein is even more sensitive and quantitative than scanning probe microscopy, an imaging technique that can possibly damage the sample. The new technique is expected to benefit the electrical evaluation of fragile or soft materials along with LSI materials.

Aqua splint suture technique in isolated zygomatic arch fractures.

PubMed

Kim, Dong-Kyu; Kim, Seung Kyun; Lee, Jun Ho; Park, Chan Hum

2014-04-01

Various methods have been used to treat zygomatic arch fractures, but no optimal modality exists for reducing these fractures and supporting the depressed bone fragments without causing esthetic problems and discomfort for life. We developed a novel aqua splint and suture technique for stabilizing isolated zygomatic arch fractures. The objective of this study is to evaluate the effect of novel aqua splint and suture technique in isolated zygomatic arch fractures. Patients with isolated zygomatic arch fractures were treated by a single surgeon in a single center from January 2000 through December 2012. Classic Gillies approach without external fixation was performed from January 2000 to December 2003, while the novel technique has been performed since 2004. 67 consecutive patients were included (Classic method, n = 32 and Novel method, n = 35). An informed consent was obtained from all patients. The novel aqua splint and suture technique was performed by the following fashion: first, we evaluated intraoperatively the bony alignment by ultrasonography and then, reduced the depressed fracture surgically using the Gillies approach. Thereafter, to stabilize the fracture and obtain the smooth facial figure, we made an aqua splint that fit the facial contour and placed monofilament nonabsorbable sutures around the fractured zygomatic arch. The novel aqua splint and suture technique showed significantly correlated with better cosmetic and functional results. In conclusion, the aqua splint suture technique is very simple, quick, safe, and effective for stabilizing repositioned zygomatic arch fractures. The aqua splint suture technique can be a good alternative procedure in isolated zygomatic arch fractures.

Statistical approach for selection of biologically informative genes.

PubMed

Das, Samarendra; Rai, Anil; Mishra, D C; Rai, Shesh N

2018-05-20

Selection of informative genes from high dimensional gene expression data has emerged as an important research area in genomics. Many gene selection techniques have been proposed so far are either based on relevancy or redundancy measure. Further, the performance of these techniques has been adjudged through post selection classification accuracy computed through a classifier using the selected genes. This performance metric may be statistically sound but may not be biologically relevant. A statistical approach, i.e. Boot-MRMR, was proposed based on a composite measure of maximum relevance and minimum redundancy, which is both statistically sound and biologically relevant for informative gene selection. For comparative evaluation of the proposed approach, we developed two biological sufficient criteria, i.e. Gene Set Enrichment with QTL (GSEQ) and biological similarity score based on Gene Ontology (GO). Further, a systematic and rigorous evaluation of the proposed technique with 12 existing gene selection techniques was carried out using five gene expression datasets. This evaluation was based on a broad spectrum of statistically sound (e.g. subject classification) and biological relevant (based on QTL and GO) criteria under a multiple criteria decision-making framework. The performance analysis showed that the proposed technique selects informative genes which are more biologically relevant. The proposed technique is also found to be quite competitive with the existing techniques with respect to subject classification and computational time. Our results also showed that under the multiple criteria decision-making setup, the proposed technique is best for informative gene selection over the available alternatives. Based on the proposed approach, an R Package, i.e. BootMRMR has been developed and available at https://cran.r-project.org/web/packages/BootMRMR. This study will provide a practical guide to select statistical techniques for selecting informative genes from high dimensional expression data for breeding and system biology studies. Published by Elsevier B.V.

Endoscopic Ultrasound-guided Specimen Collection and Evaluation Techniques Affect Diagnostic Accuracy.

PubMed

Bang, Ji Young; Navaneethan, Udayakumar; Hasan, Muhammad K; Hawes, Robert; Varadarajulu, Shyam

2018-03-11

Outcomes of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) evaluation vary with technique, needles, and methods of specimen evaluation. We performed a direct comparison of diagnostic yields of EUS-FNA samples collected using different gauge needles (22- vs 25-gauge), with or without suction. We performed a randomized controlled study of 352 patients with suspected pancreatic masses, referred for EUS-FNA at a tertiary referral center. Patients were randomly assigned to 22-gauge needles with or without suction or 25-gauge needles with or without suction. Specimens were evaluated offsite by cell block and rapid onsite cytologic evaluation (ROSE). Final diagnoses were made based on histologic analyses or 12-month follow-up evaluations. The primary outcome was diagnostic adequacy of cell blocks. Secondary outcomes were operating characteristics of ROSE and EUS-FNA, number of passes required for accurate onsite diagnosis, and amount of blood in specimens. The final diagnoses were malignancy (81.5% of patients) and benign disease (17.0% of patients); 1.4% of patients were lost during follow up. Cell block, ROSE, and EUS-FNA led to diagnostic accuracies of 71.9%, 95.5%, and 96.6%, respectively. A 22-gauge needle with suction was associated with more passes for adequate onsite diagnosis (P = .003) and specimens contained more blood (P = .01). Diagnostic accuracy of specimens collected by transduodenal EUS-FNA was lower with 22-gauge needles with suction compared to other techniques (P = .004). In a randomized trial of patients undergoing EUS-FNA for pancreatic masses, samples collected with 22-gauge vs 25-gauge needles performed equally well for offsite specimen evaluation. Use of suction appears to increase number of passes needed and specimen bloodiness. Specimen collection techniques should be individualized based on method of evaluation. ClinicalTrials.gov no: NCT02424838. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Expanded Awareness of Student Performance: A Case Study in Applied Ethnographic Monitoring in a Bilingual Classroom. Sociolinguistic Working Paper Number 60.

ERIC Educational Resources Information Center

Carrasco, Robert L.

The case study of the use of a classroom observation technique to evaluate the abilities and performance of a bilingual kindergarten student previously assessed as a low achiever is described. There are three objectives: to show the validity of the ethnographic monitoring technique, to show the value of teachers as collaborating researchers, and…

Geophysical background and as-built target characteristics

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

Allen, J.W.

1994-09-01

The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) has provided a facility for DOE, other Government agencies, and the private sector to evaluate and document the utility of specific geophysical measurement techniques for detecting and defining cultural and environmental targets. This facility is the Rabbit Valley Geophysics Performance Evaluation Range (GPER). Geophysical surveys prior to the fiscal year (FY) 1994 construction of new test cells showed the primary test area to be relatively homogeneous and free from natural or man-made artifacts, which would generate spurious responses in performance evaluation data. Construction of nine new cell areas inmore » Rabbit Valley was completed in June 1994 and resulted in the emplacement of approximately 150 discrete targets selected for their physical and electrical properties. These targets and their geophysical environment provide a broad range of performance evaluation parameters from ``very easy to detect`` to ``challenging to the most advanced systems.`` Use of nonintrusive investigative techniques represents a significant improvement over intrusive characterization methods, such as drilling or excavation, because there is no danger of exposing personnel to possible hazardous materials and no risk of releasing or spreading contamination through the characterization activity. Nonintrusive geophysical techniques provide the ability to infer near-surface structure and waste characteristics from measurements of physical properties associated with those targets.« less

Objective evaluation of reconstruction methods for quantitative SPECT imaging in the absence of ground truth.

PubMed

Jha, Abhinav K; Song, Na; Caffo, Brian; Frey, Eric C

2015-04-13

Quantitative single-photon emission computed tomography (SPECT) imaging is emerging as an important tool in clinical studies and biomedical research. There is thus a need for optimization and evaluation of systems and algorithms that are being developed for quantitative SPECT imaging. An appropriate objective method to evaluate these systems is by comparing their performance in the end task that is required in quantitative SPECT imaging, such as estimating the mean activity concentration in a volume of interest (VOI) in a patient image. This objective evaluation can be performed if the true value of the estimated parameter is known, i.e. we have a gold standard. However, very rarely is this gold standard known in human studies. Thus, no-gold-standard techniques to optimize and evaluate systems and algorithms in the absence of gold standard are required. In this work, we developed a no-gold-standard technique to objectively evaluate reconstruction methods used in quantitative SPECT when the parameter to be estimated is the mean activity concentration in a VOI. We studied the performance of the technique with realistic simulated image data generated from an object database consisting of five phantom anatomies with all possible combinations of five sets of organ uptakes, where each anatomy consisted of eight different organ VOIs. Results indicate that the method provided accurate ranking of the reconstruction methods. We also demonstrated the application of consistency checks to test the no-gold-standard output.

Evaluation Processes Used to Assess the Effectiveness of Vocational-Technical Programs.

ERIC Educational Resources Information Center

Bruhns, Arthur E.

Evaluation is quantitative or qualitative, the criteria determined by or given to the student. The criteria show how close he has come to the program's objectives and the ranking of individual performance. Vocational education programs susceptible to evaluation are listed and relevant evaluative techniques discussed. Graduate interviews concerning…

Comparative urologic complications of ureteroneocystostomy in kidney transplantation: transvesical Leadbetter-Politano versus extravesical Lich-Gregoir technique.

PubMed

Baston, C; Harza, M; Preda, A; Gener, I; Manea, I; Voinea, S; Olaru, V; Badescu, B; Sinescu, I

2014-01-01

The incidence of urologic complications after kidney transplantation remains high despite improvements in diagnosis and operative techniques. Urinary tract reconstruction is usually done by ureteroneocystostomy (UCNS), and several techniques are available. In this study, we evaluated the outcomes of 2 different UCNS techniques performed in our department, the transvesical Leadbetter-Politano (L-P) and the extravesical Lich-Gregoire (L-G) technique. We evaluated the outcomes of 2 different UCNS techniques, L-P versus L-G, performed in our department between July 1, 2006, and December 31, 2011. During this period, we performed 524 consecutive renal transplantations-264 cases using the L-P technique (50.3%) and 260 cases with L-G technique (49.7%). Renal grafts were obtained from cadaveric donors in 146 cases (27.86%) and from living-related donors in 378 cases (72.14%). Recipient mean age was 35.64 years and the male to female ratio was 1.63:1. Urologic complications after kidney transplantation occurred in 22 cases in the L-P UCNS group (8.33%). The most common complications were ureteral stenosis (3.41%) and leakage (2.65%). Other complications recorded were lymphoceles (1.89%) and hematoma with secondary ureteral obstruction (0.38%). Compared with the L-P UCNS technique, the L-G technique was associated with fewer overall complications (6.15% vs 8.33%; P = .06), a lesser rate of ureteral stenosis (2.31% vs 3.41%; P = .08), and a similar rate of leakage. However, statistical analysis revealed no differences between the 2 techniques (P = .06). In addition, we did not note any differences in graft and patient survival between the 2 groups. In our study, the extravesical L-G technique has a lower complication rate compared with transvesical L-P procedure, but without statistical differences. Furthermore, the L-G technique is easier and faster to perform, it avoids a separate cystotomy, and requires a shorter ureteral length. In conclusion, we recommend L-G technique as technique of choice in kidney transplantation. Copyright © 2014 Elsevier Inc. All rights reserved.

FY71 Engineering Report on Surveillance Techniques for Civil Aviation Security

DOT National Transportation Integrated Search

1971-11-01

This document discusses the work performed by the TSC task group on surveillance techniques in FY71. The principal section is devoted to the technical description, classification and evaluation of commercial metal detectors for concealed weapons. It ...

Comprehensive comparison of gap filling techniques for eddy covariance net carbon fluxes

NASA Astrophysics Data System (ADS)

Moffat, A. M.; Papale, D.; Reichstein, M.; Hollinger, D. Y.; Richardson, A. D.; Barr, A. G.; Beckstein, C.; Braswell, B. H.; Churkina, G.; Desai, A. R.; Falge, E.; Gove, J. H.; Heimann, M.; Hui, D.; Jarvis, A. J.; Kattge, J.; Noormets, A.; Stauch, V. J.

2007-12-01

Review of fifteen techniques for estimating missing values of net ecosystem CO2 exchange (NEE) in eddy covariance time series and evaluation of their performance for different artificial gap scenarios based on a set of ten benchmark datasets from six forested sites in Europe. The goal of gap filling is the reproduction of the NEE time series and hence this present work focuses on estimating missing NEE values, not on editing or the removal of suspect values in these time series due to systematic errors in the measurements (e.g. nighttime flux, advection). The gap filling was examined by generating fifty secondary datasets with artificial gaps (ranging in length from single half-hours to twelve consecutive days) for each benchmark dataset and evaluating the performance with a variety of statistical metrics. The performance of the gap filling varied among sites and depended on the level of aggregation (native half- hourly time step versus daily), long gaps were more difficult to fill than short gaps, and differences among the techniques were more pronounced during the day than at night. The non-linear regression techniques (NLRs), the look-up table (LUT), marginal distribution sampling (MDS), and the semi-parametric model (SPM) generally showed good overall performance. The artificial neural network based techniques (ANNs) were generally, if only slightly, superior to the other techniques. The simple interpolation technique of mean diurnal variation (MDV) showed a moderate but consistent performance. Several sophisticated techniques, the dual unscented Kalman filter (UKF), the multiple imputation method (MIM), the terrestrial biosphere model (BETHY), but also one of the ANNs and one of the NLRs showed high biases which resulted in a low reliability of the annual sums, indicating that additional development might be needed. An uncertainty analysis comparing the estimated random error in the ten benchmark datasets with the artificial gap residuals suggested that the techniques are already at or very close to the noise limit of the measurements. Based on the techniques and site data examined here, the effect of gap filling on the annual sums of NEE is modest, with most techniques falling within a range of ±25 g C m-2 y-1.

Dispersant use as a response to oil spills: toxicological effects on fish cardiac performance.

PubMed

Milinkovitch, Thomas; Thomas-Guyon, Hélène; Lefrançois, Christel; Imbert, Nathalie

2013-04-01

Dispersant use is a controversial technique used to respond to oil spills in nearshore areas. In order to assess the toxicity of this technique, this study evaluated the cardiac toxicological effects on juvenile golden grey mullets Liza aurata exposed for 48 h to either dispersant alone, chemically dispersed oil, mechanically dispersed oil, the water-soluble fraction of oil or a control condition. Following exposure, the positive inotropic effects of adrenaline were assessed in order to evaluate a potential impairment on the cardiac performance. The results revealed an impairment of the positive inotropic effects of adrenaline for all the contaminants (single dispersant, dispersed and undispersed oil, water-soluble fraction of oil). This suggests that: (1) cardiac performance is a valuable parameter to study the physiopathological effects of dispersed oil; (2) dispersant application is likely to impair cardiac performance.

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.

Determining the Number of Factors in P-Technique Factor Analysis

ERIC Educational Resources Information Center

Lo, Lawrence L.; Molenaar, Peter C. M.; Rovine, Michael

2017-01-01

Determining the number of factors is a critical first step in exploratory factor analysis. Although various criteria and methods for determining the number of factors have been evaluated in the usual between-subjects R-technique factor analysis, there is still question of how these methods perform in within-subjects P-technique factor analysis. A…

Prospective Study of the Surgical Techniques Used in Primary Rhinoplasty on the Caucasian Nose and Comparison of the Preoperative and Postoperative Anthropometric Nose Measurements

PubMed Central

Berger, Cezar Augusto Sarraf; Freitas, Renato da Silva; Malafaia, Osvaldo; Pinto, José Simão de Paula; Macedo Filho, Evaldo Dacheux; Mocellin, Marcos; Fagundes, Marina Serrato Coelho

2014-01-01

Introduction The knowledge and study of surgical techniques and anthropometric measurements of the nose make possible a qualitative and quantitative analysis of surgical results. Objective Study the main technique used in rhinoplasty on Caucasian noses and compare preoperative and postoperative anthropometric measurements of the nose. Methods A prospective study with 170 patients was performed at a private hospital. Data were collected using the Electronic System Integrated of Protocols software (Sistema Integrado de Protocolos Eletrônicos, SINPE©). The surgical techniques used in the nasal dorsum and tip were evaluated. Preoperative and 12-month follow-up photos as well as the measurements compared with the ideal aesthetic standard of a Caucasian nose were analyzed objectively. Student t test and standard deviation test were applied. Results There was a predominance of endonasal access (94.4%). The most common dorsum technique was hump removal (33.33%), and the predominance of sutures (24.76%) was observed on the nasal tip, with the lateral intercrural the most frequent (32.39%). Comparison between preoperative and postoperative photos found statistically significant alterations on the anthropometric measurements of the noses. Conclusion The main surgical techniques on Caucasian noses were evaluated, and a great variety was found. The evaluation of anthropometric measurements of the nose proved the efficiency of the performed procedures. PMID:25992149

Image coding of SAR imagery

NASA Technical Reports Server (NTRS)

Chang, C. Y.; Kwok, R.; Curlander, J. C.

1987-01-01

Five coding techniques in the spatial and transform domains have been evaluated for SAR image compression: linear three-point predictor (LTPP), block truncation coding (BTC), microadaptive picture sequencing (MAPS), adaptive discrete cosine transform (ADCT), and adaptive Hadamard transform (AHT). These techniques have been tested with Seasat data. Both LTPP and BTC spatial domain coding techniques provide very good performance at rates of 1-2 bits/pixel. The two transform techniques, ADCT and AHT, demonstrate the capability to compress the SAR imagery to less than 0.5 bits/pixel without visible artifacts. Tradeoffs such as the rate distortion performance, the computational complexity, the algorithm flexibility, and the controllability of compression ratios are also discussed.

Objective and automated protocols for the evaluation of biomedical search engines using No Title Evaluation protocols.

PubMed

Campagne, Fabien

2008-02-29

The evaluation of information retrieval techniques has traditionally relied on human judges to determine which documents are relevant to a query and which are not. This protocol is used in the Text Retrieval Evaluation Conference (TREC), organized annually for the past 15 years, to support the unbiased evaluation of novel information retrieval approaches. The TREC Genomics Track has recently been introduced to measure the performance of information retrieval for biomedical applications. We describe two protocols for evaluating biomedical information retrieval techniques without human relevance judgments. We call these protocols No Title Evaluation (NT Evaluation). The first protocol measures performance for focused searches, where only one relevant document exists for each query. The second protocol measures performance for queries expected to have potentially many relevant documents per query (high-recall searches). Both protocols take advantage of the clear separation of titles and abstracts found in Medline. We compare the performance obtained with these evaluation protocols to results obtained by reusing the relevance judgments produced in the 2004 and 2005 TREC Genomics Track and observe significant correlations between performance rankings generated by our approach and TREC. Spearman's correlation coefficients in the range of 0.79-0.92 are observed comparing bpref measured with NT Evaluation or with TREC evaluations. For comparison, coefficients in the range 0.86-0.94 can be observed when evaluating the same set of methods with data from two independent TREC Genomics Track evaluations. We discuss the advantages of NT Evaluation over the TRels and the data fusion evaluation protocols introduced recently. Our results suggest that the NT Evaluation protocols described here could be used to optimize some search engine parameters before human evaluation. Further research is needed to determine if NT Evaluation or variants of these protocols can fully substitute for human evaluations.

A prospective outcome and cost-effectiveness comparison between two ligament reattachment techniques using suture anchors for chronic ankle instability.

PubMed

Cho, Byung-Ki; Kim, Yong-Min; Park, Kyoung-Jin; Park, Ji-Kang; Kim, Do-Kyoon

2015-02-01

There are various ligament reattachment techniques for the modified Brostrom procedure. There have been few comparative studies on recently developed techniques. This prospective study was performed to compare the functional outcomes of 2 different ligament reattachment techniques using suture anchors. We furthermore evaluated the cost-effectiveness of the suture bridge technique. Forty-five amateur athletes under 30 years of age were followed for more than 2 years. Twenty-four procedures with the suture anchor technique and 21 procedures with the suture bridge technique were performed by one surgeon. The functional evaluation consisted of the American Orthopaedic Foot & Ankle Society (AOFAS) score, Foot and Ankle Outcome Score (FAOS), Karlsson score, Sefton grading system, and the period to return to various forms of exercise (jogging, spurt running, jumping, one leg standing for >1 minute, walking on uneven ground, and going down stairs). Measurement of talar tilt angle and anterior talar translation was obtained from stress radiographs to evaluate mechanical stability. There were no significant differences on AOFAS score, FAOS, Karlsson score, Sefton grade, and stress radiographs. There were no significant differences on the return to exercises, except for jumping. As the most common complication, there were 3 cases of skin irritation by suture materials in the suture anchor group and 2 cases of intraoperative breakage of the suture anchor in suture bridge group. Both ligament reattachment techniques using suture anchors showed similar functional outcomes. Considering the additional medical expenses incurred by more suture anchors, the modified Brostrom procedure using the suture bridge technique had low cost-effectiveness. Proper indication and clinical usefulness of suture bridge technique for chronic ankle instability will be addressed in further studies. Level II, prospective comparative study. © The Author(s) 2014.

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.

Evaluating a de-cluttering technique for NextGen RNAV and RNP charts

DOT National Transportation Integrated Search

2012-10-14

The authors propose a de-cluttering technique to simplify the depiction of visually complex Area Navigation (RNAV) and Required Navigation Performance (RNP) procedures by reducing the number of paths shown on a single chart page. An experiment was co...

Single-Incision Transumbilical Surgery (SITUS) versus Single-Port Laparoscopic Surgery and conventional laparoscopic surgery: a prospective randomized comparative study of performance with novices in a dry laboratory.

PubMed

Schoenthaler, Martin; Avcil, Tuba; Sevcenco, Sabina; Nagele, Udo; Hermann, Thomas E W; Kuehhas, Franklin E; Shariat, Shahrokh F; Frankenschmidt, Alexander; Wetterauer, Ulrich; Miernik, Arkadiusz

2015-01-01

To evaluate the Single-Incision Transumbilical Surgery (SITUS) technique as compared to an established laparoendoscopic single-site surgery (LESS) technique (Single-Port Laparoscopic Surgery, SPLS) and conventional laparoscopy (CLS) in a surgical simulator model. Sixty-three medical students without previous laparoscopic experience were randomly assigned to one of the three groups (SITUS, SPLS and CLS). Subjects were asked to perform five standardized tasks of increasing difficulty adopted from the Fundamentals of Laparoscopic Surgery curriculum. Statistical evaluation included task completion times and accuracy. Overall performances of all tasks (except precision cutting) were significantly faster and of higher accuracy in the CLS and SITUS groups than in the SPLS group (p = 0.004 to p < 0.001). CLS and SITUS groups alone showed no significant difference in performance times and accuracy measurements for all tasks (p = 0.048 to p = 0.989). SITUS proved to be a simple, but highly effective technique to overcome restrictions of SPLS. In a surgical simulator model, novices were able to achieve task performances comparable to CLS and did significantly better than using a port-assisted LESS technique such as SPLS. The demonstrated advantages of SITUS may be attributed to a preservation of the basic principles of conventional laparoscopy, such as the use of straight instruments and an adequate degree of triangulation.

Analysis and Performance Evaluation of Electrocardiogram Data compression Techniques.

DTIC Science & Technology

1980-12-01

techniques were investigated for potential real time implementation on an 8 bit Motorola 6800 microprocessor. Research indicated entropy reduction transform...EKG has been an area of active research since the late nineteen sixties. References (1) , (7) , (12) ,(26) ,(28) , (29) .(32) ,(33) , and (35) are...representative of the research efforts performed in the last ten years . The reasons for compressing EKG data are twofold: 1) digita" storage costs are

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.

Evaluation of modified Dennis parasitological technique for diagnosis of bovine fascioliasis.

PubMed

Correa, Stefanya; Martínez, Yudy Liceth; López, Jessika Lissethe; Velásquez, Luz Elena

2016-02-23

Bovine fascioliasis causes important economic losses, estimated at COP$ 12,483 billion per year; its prevalence is 25% in dairy cattle. Parasitological techniques are required for it diagnosis. The Dennis technique, modified in 2002, is the one used in Colombia, but its sensitivity, specificity and validity are not known.  To evaluate the validity and performance of the modified Dennis technique for diagnosis of bovine fascioliasis using as reference test the observation of parasites in the liver.  We conducted a diagnostic evaluation study. We selected a convenience sample of discarded bovines sacrificed between March and June, 2013, in Frigocolanta for the study. We collected 25 g of feces from each animal and their liver and bile ducts were examined for Fasciola hepatica. The sensitivity, specificity, predictive positive value, predictive negative value, and validity index were calculated with 95% confidence intervals. The post-mortem evaluation was used as the gold standard.  We analyzed 180 bovines. The sensitivity and specificity of the modified Dennis technique were 73.2% (95% CI=58.4% - 87.9%) and 84.2% (95% CI= 77.7% - 90.6%), respectively. The positive predictive value was 57.7% (95% CI= 43.3% - 72.1%) and the negative one 91.4% (95% CI= 86.2% - 96.6%). The prevalence of bovine fascioliasis was 22.8% (95% CI= 16.4% - 29.2%).  The validity and the performance of the modified Dennis technique were higher than those of the traditional one, which makes it a good screening test for diagnosing fascioliasis for population and prevalence studies and during animal health campaigns.

Comparative measurement of collagen bundle orientation by Fourier analysis and semiquantitative evaluation: reliability and agreement in Masson's trichrome, Picrosirius red and confocal microscopy techniques.

PubMed

Marcos-Garcés, V; Harvat, M; Molina Aguilar, P; Ferrández Izquierdo, A; Ruiz-Saurí, A

2017-08-01

Measurement of collagen bundle orientation in histopathological samples is a widely used and useful technique in many research and clinical scenarios. Fourier analysis is the preferred method for performing this measurement, but the most appropriate staining and microscopy technique remains unclear. Some authors advocate the use of Haematoxylin-Eosin (H&E) and confocal microscopy, but there are no studies comparing this technique with other classical collagen stainings. In our study, 46 human skin samples were collected, processed for histological analysis and stained with Masson's trichrome, Picrosirius red and H&E. Five microphotographs of the reticular dermis were taken with a 200× magnification with light microscopy, polarized microscopy and confocal microscopy, respectively. Two independent observers measured collagen bundle orientation with semiautomated Fourier analysis with the Image-Pro Plus 7.0 software and three independent observers performed a semiquantitative evaluation of the same parameter. The average orientation for each case was calculated with the values of the five pictures. We analyzed the interrater reliability, the consistency between Fourier analysis and average semiquantitative evaluation and the consistency between measurements in Masson's trichrome, Picrosirius red and H&E-confocal. Statistical analysis for reliability and agreement was performed with the SPSS 22.0 software and consisted of intraclass correlation coefficient (ICC), Bland-Altman plots and limits of agreement and coefficient of variation. Interrater reliability was almost perfect (ICC > 0.8) with all three histological and microscopy techniques and always superior in Fourier analysis than in average semiquantitative evaluation. Measurements were consistent between Fourier analysis by one observer and average semiquantitative evaluation by three observers, with an almost perfect agreement with Masson's trichrome and Picrosirius red techniques (ICC > 0.8) and a strong agreement with H&E-confocal (0.7 < ICC < 0.8). Comparison of measurements between the three techniques for the same observer showed an almost perfect agreement (ICC > 0.8), better with Fourier analysis than with semiquantitative evaluation (single and average). These results in nonpathological skin samples were also confirmed in a preliminary analysis in eight scleroderma skin samples. Our results show that Masson's trichrome and Picrosirius red are consistent with H&E-confocal for measuring collagen bundle orientation in histological samples and could thus be used indistinctly for this purpose. Fourier analysis is superior to average semiquantitative evaluation and should keep being used as the preferred method. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Comparing the frequency of physical examination techniques performed by associate and baccalaureate degree prepared nurses in clinical practice: does education make a difference?

PubMed

Giddens, Jean

2006-03-01

Rapid changes in health care have underscored the need for reform in health professions education, including nursing education. One of many problems cited in the nursing and other health sciences education literature is overcrowded curricula; therefore, an evaluation of content is necessary. The purpose of this study was to determine whether differences exist in the frequency that physical examination techniques are performed by associate and baccalaureate degree prepared nurses. Participants completed a survey on performance of various physical examination techniques. A Mann-Whitney test showed no differences between the two groups in terms of frequency of techniques performed. A small negative correlation was found between frequency and years of experience with the nutrition assessment category. A comparison of physical examination content covered in baccalaureate and associate degree nursing programs is needed to further understand these findings.

Evaluation Techniques for Individualized Instruction: Revision and Summative Evaluation.

ERIC Educational Resources Information Center

Englert, DuWayne C.; And Others

1987-01-01

Describes the collection and analysis of summative data for a slide/tape self-instruction program on an introductory zoology course. Points of concern regarding curricular changes, teaching assistant training, student use, student performance evaluation, development, and revision are discussed from their unique perspectives within the summative…

Stereotactic Radiofrequency Ablation (SRFA) of Liver Lesions: Technique Effectiveness, Safety, and Interoperator Performance

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

Widmann, Gerlig, E-mail: gerlig.widmann@i-med.ac.at; Schullian, Peter, E-mail: peter.schullian@i-med.ac.at; Haidu, Marion, E-mail: marion.haidu@i-med.ac.at

Purpose: To evaluate technique effectiveness, safety, and interoperator performance of stereotactic radiofrequency ablation (SRFA) of liver lesions. Methods: Retrospective review including 90 consecutive patients from January 2008 to January 2010 with 106 computed tomography-guided SRFA sessions using both single and multiple electrodes for the treatment of 177 lesions: 72 hepatocellular carcinoma (HCC) and 105 metastases with a mean size of 2.9 cm (range 0.5-11 cm). Technique effectiveness and 1-year local recurrence were evaluated by computed tomographic scans. Complications, mortality, and hospital days were recorded. The performance between an experienced and inexperienced interventional radiologist was compared. Results: The overall technique effectivenessmore » after a single SRFA was 95.5% (93.1% for HCC and 97.1% for metastases). Four of the eight unsuccessfully treated lesions could be retreated (secondary technique effectiveness of 97.7%). Local recurrence at 1 year was 2.9%. Technique effectiveness was significantly different for lesions <5 cm (96.7%) and >5 cm (87.5%) (P = 0.044) but not for lesions <3 cm (95.9%) and 3-5 cm (100%). Compared to clear parenchymal property (97.3%), vessel vicinity (93.3%) (P = 0.349) and subcapsular (95.2%) (P = 0.532) had no, but hollow viscera vicinity (83.3%) had a significantly lower technique effectiveness (P = 0.020). Mortality rate was 0.9%. Major complications and hospital days were higher for cirrhosis Child-Pugh B (20%, 7.2 days) than Child-Pugh A (3.1%, 4.7 days) patients and for metastases (5.1%, 4.3 days). There was no significant difference in interoperator performance. Conclusions: RFA allowed for efficient, reliable, and safe ablation of large-volume liver disease.« less

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...

Implementation and evaluation of a dilation and evacuation simulation training curriculum.

PubMed

York, Sloane L; McGaghie, William C; Kiley, Jessica; Hammond, Cassing

2016-06-01

To evaluate obstetrics and gynecology resident physicians' performance following a simulation curriculum on dilation and evacuation (D&E) procedures. This study included two phases: simulation curriculum development and resident physician performance evaluation following training on a D&E simulator. Trainees participated in two evaluations. Simulation training evaluated participants performing six cases on a D&E simulator, measuring procedural time and a 26-step checklist of D&E steps. The operative training portion evaluated residents' performance after training on the simulator using mastery learning techniques. Intra-operative evaluation was based on a 21-step checklist score, Objective Structured Assessment of Technical Skills (OSATS), and percentage of cases completed. Twenty-two residents participated in simulation training, demonstrating improved performance from cases one and two to cases five and six, as measured by checklist score and procedural time (p<.001 and p=.001, respectively). Of 10 participants in the operative training, all performed at least three D&Es, while seven performed at least six cases. While checklist scores did not change significantly from the first to sixth case (mean for first case: 18.3; for sixth case: 19.6; p=.593), OSATS ratings improved from case one (19.7) to case three (23.5; p=.001) and to case six (26.8; p=.005). Trainees completed approximately 71.6% of their first case (range: 21.4-100%). By case six, the six participants performed 81.2% of the case (range: 14.3-100%). D&E simulation using a newly-developed uterine model and simulation curriculum improves resident technical skills. Simulation training with mastery learning techniques transferred to high level of performance in OR using checklist. The OSATS measured skills and showed improvement in performance with subsequent cases. Implementation of a D&E simulation curriculum offers potential for improved surgical training and abortion provision. Copyright © 2016 Elsevier Inc. All rights reserved.

Generalized approach for identification and evaluation of technology-insertion options for military avionics systems

NASA Astrophysics Data System (ADS)

Harkness, Linda L.; Sjoberg, Eric S.

1996-06-01

The Georgia Tech Research Institute, sponsored by the Warner Robins Air Logistics Center, has developed an approach for efficiently postulating and evaluating methods for extending the life of radars and other avionics systems. The technique identified specific assemblies for potential replacement and evaluates the system level impact, including performance, reliability and life-cycle cost of each action. The initial impetus for this research was the increasing obsolescence of integrated circuits contained in the AN/APG-63 system. The operational life of military electronics is typically in excess of twenty years, which encompasses several generations of IC technology. GTRI has developed a systems approach to inserting modern technology components into older systems based upon identification of those functions which limit the system's performance or reliability and which are cost drivers. The presentation will discuss the above methodology and a technique for evaluating and ranking the different potential system upgrade options.

Dynamic Assessment for 3- and 4-Year-Old Children Who Use Augmentative and Alternative Communication: Evaluating Expressive Syntax

ERIC Educational Resources Information Center

Binger, Cathy; Kent-Walsh, Jennifer; King, Marika

2017-01-01

Purpose: The developmental readiness to produce early sentences with an iPad communication application was assessed with ten 3- and 4-year-old children with severe speech disorders using graduated prompting dynamic assessment (DA) techniques. The participants' changes in performance within the DA sessions were evaluated, and DA performance was…

Development and validation of a sensor-based health monitoring model for the Parkview Bridge deck.

DOT National Transportation Integrated Search

2012-01-31

Accelerated bridge construction (ABC) using full-depth precast deck panels is an innovative technique that brings all : the benefits listed under ABC to full fruition. However, this technique needs to be evaluated and the performance of : the bridge ...

[Health protection for rural workers: the need to standardize techniques for quantifying dermal exposure to pesticides].

PubMed

Selmi, Giuliana da Fontoura Rodrigues; Trapé, Angelo Zanaga

2014-05-01

Quantification of dermal exposure to pesticides in rural workers, used in risk assessment, can be performed with different techniques such as patches or whole body evaluation. However, the wide variety of methods can jeopardize the process by producing disparate results, depending on the principles in sample collection. A critical review was thus performed on the main techniques for quantifying dermal exposure, calling attention to this issue and the need to establish a single methodology for quantification of dermal exposure in rural workers. Such harmonization of different techniques should help achieve safer and healthier working conditions. Techniques that can provide reliable exposure data are an essential first step towards avoiding harm to workers' health.

Description and Evaluation of a Measurement Technique for Assessment of Performing Gender

PubMed Central

Harris, Kathleen Mullan; Halpern, Carolyn Tucker

2016-01-01

The influence of masculinity and femininity on behaviors and outcomes has been extensively studied in social science research using various measurement strategies. In the present paper, we describe and evaluate a measurement technique that uses existing survey items to capture the extent to which an individual behaves similarly to their same-gender peers. We use data from the first four waves of The National Longitudinal Study of Adolescent to Adult Health (Add Health), a nationally representative sample of adolescents (age 12–18) in the United States who were re-interviewed at ages 13–19, 18–26, and 24–32. We estimate split-half reliability and provide evidence that supports the validity of this measurement technique. We demonstrate that the resulting measure does not perform as a trait measure and is associated with involvement in violent fights, a pattern consistent with theory and empirical findings. This measurement technique represents a novel approach for gender researchers with the potential for expanding our current knowledge base. PMID:28630528

Mathematics Competency for Beginning Chemistry Students Through Dimensional Analysis.

PubMed

Pursell, David P; Forlemu, Neville Y; Anagho, Leonard E

2017-01-01

Mathematics competency in nursing education and practice may be addressed by an instructional variation of the traditional dimensional analysis technique typically presented in beginning chemistry courses. The authors studied 73 beginning chemistry students using the typical dimensional analysis technique and the variation technique. Student quantitative problem-solving performance was evaluated. Students using the variation technique scored significantly better (18.3 of 20 points, p < .0001) on the final examination quantitative titration problem than those who used the typical technique (10.9 of 20 points). American Chemical Society examination scores and in-house assessment indicate that better performing beginning chemistry students were more likely to use the variation technique rather than the typical technique. The variation technique may be useful as an alternative instructional approach to enhance beginning chemistry students' mathematics competency and problem-solving ability in both education and practice. [J Nurs Educ. 2017;56(1):22-26.]. Copyright 2017, SLACK Incorporated.

ANATOMICAL RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT OF THE KNEE: DOUBLE BAND OR SINGLE BAND?

PubMed

Zanella, Luiz Antonio Zanotelli; Junior, Adair Bervig; Badotti, Augusto Alves; Michelin, Alexandre Froes; Algarve, Rodrigo Ilha; de Quadros Martins, Cesar Antonio

2012-01-01

To evaluate the double-band and single-band techniques for anatomical reconstruction of the anterior cruciate ligament of the knee and demonstrate that the double-band technique not only provides greater anterior stability but also causes less pain and a better subjective patient response. We selected 42 patients who underwent anterior cruciate ligament reconstruction, by means of either the single-band anatomical reconstruction technique, using flexor tendon grafts with two tunnels, or the double-band anatomical reconstruction technique, using four tunnels and grafts from the semitendinosus and gracilis tendons. All fixations were performed using interference screws. There was no variation in the sample. Before the operation, the objective and subjective IKDC scores, Lysholm score and length of time with the injury were evaluated. All these variables were reassessed six months later, and the KT-1000 correlation with the contralateral knee was also evaluated. There was no significant difference between the two groups in subjective evaluations, but the single-band group showed better results in relation to range of motion and objective evaluations including KT-1000 (with statistical significance). Our study demonstrated that there was no difference between the two groups in subjective evaluations, but better results were found using the single-band anatomical technique, in relation to objective evaluations.

ANATOMICAL RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT OF THE KNEE: DOUBLE BAND OR SINGLE BAND?

PubMed Central

Zanella, Luiz Antonio Zanotelli; Junior, Adair Bervig; Badotti, Augusto Alves; Michelin, Alexandre Froes; Algarve, Rodrigo Ilha; de Quadros Martins, Cesar Antonio

2015-01-01

Objective: To evaluate the double-band and single-band techniques for anatomical reconstruction of the anterior cruciate ligament of the knee and demonstrate that the double-band technique not only provides greater anterior stability but also causes less pain and a better subjective patient response. Methods: We selected 42 patients who underwent anterior cruciate ligament reconstruction, by means of either the single-band anatomical reconstruction technique, using flexor tendon grafts with two tunnels, or the double-band anatomical reconstruction technique, using four tunnels and grafts from the semitendinosus and gracilis tendons. All fixations were performed using interference screws. There was no variation in the sample. Before the operation, the objective and subjective IKDC scores, Lysholm score and length of time with the injury were evaluated. All these variables were reassessed six months later, and the KT-1000 correlation with the contralateral knee was also evaluated. Results: There was no significant difference between the two groups in subjective evaluations, but the single-band group showed better results in relation to range of motion and objective evaluations including KT-1000 (with statistical significance). Conclusion: Our study demonstrated that there was no difference between the two groups in subjective evaluations, but better results were found using the single-band anatomical technique, in relation to objective evaluations. PMID:27042621

Real-time in-flight engine performance and health monitoring techniques for flight research application

NASA Technical Reports Server (NTRS)

Ray, Ronald J.; Hicks, John W.; Wichman, Keith D.

1991-01-01

Procedures for real time evaluation of the inflight health and performance of gas turbine engines and related systems were developed to enhance flight test safety and productivity. These techniques include the monitoring of the engine, the engine control system, thrust vectoring control system health, and the detection of engine stalls. Real time performance techniques were developed for the determination and display of inflight thrust and for aeroperformance drag polars. These new methods were successfully shown on various research aircraft at NASA-Dryden. The capability of NASA's Western Aeronautical Test Range and the advanced data acquisition systems were key factors for implementation and real time display of these methods.

Evaluation of interpolation techniques for the creation of gridded daily precipitation (1 × 1 km2); Cyprus, 1980-2010

NASA Astrophysics Data System (ADS)

Camera, Corrado; Bruggeman, Adriana; Hadjinicolaou, Panos; Pashiardis, Stelios; Lange, Manfred A.

2014-01-01

High-resolution gridded daily data sets are essential for natural resource management and the analyses of climate changes and their effects. This study aims to evaluate the performance of 15 simple or complex interpolation techniques in reproducing daily precipitation at a resolution of 1 km2 over topographically complex areas. Methods are tested considering two different sets of observation densities and different rainfall amounts. We used rainfall data that were recorded at 74 and 145 observational stations, respectively, spread over the 5760 km2 of the Republic of Cyprus, in the Eastern Mediterranean. Regression analyses utilizing geographical copredictors and neighboring interpolation techniques were evaluated both in isolation and combined. Linear multiple regression (LMR) and geographically weighted regression methods (GWR) were tested. These included a step-wise selection of covariables, as well as inverse distance weighting (IDW), kriging, and 3D-thin plate splines (TPS). The relative rank of the different techniques changes with different station density and rainfall amounts. Our results indicate that TPS performs well for low station density and large-scale events and also when coupled with regression models. It performs poorly for high station density. The opposite is observed when using IDW. Simple IDW performs best for local events, while a combination of step-wise GWR and IDW proves to be the best method for large-scale events and high station density. This study indicates that the use of step-wise regression with a variable set of geographic parameters can improve the interpolation of large-scale events because it facilitates the representation of local climate dynamics.

The Linear Programming to evaluate the performance of Oral Health in Primary Care.

PubMed

Colussi, Claudia Flemming; Calvo, Maria Cristina Marino; Freitas, Sergio Fernando Torres de

2013-01-01

To show the use of Linear Programming to evaluate the performance of Oral Health in Primary Care. This study used data from 19 municipalities of Santa Catarina city that participated of the state evaluation in 2009 and have more than 50,000 habitants. A total of 40 indicators were evaluated, calculated using the Microsoft Excel 2007, and converted to the interval [0, 1] in ascending order (one indicating the best situation and zero indicating the worst situation). Applying the Linear Programming technique municipalities were assessed and compared among them according to performance curve named "quality estimated frontier". Municipalities included in the frontier were classified as excellent. Indicators were gathered, and became synthetic indicators. The majority of municipalities not included in the quality frontier (values different of 1.0) had lower values than 0.5, indicating poor performance. The model applied to the municipalities of Santa Catarina city assessed municipal management and local priorities rather than the goals imposed by pre-defined parameters. In the final analysis three municipalities were included in the "perceived quality frontier". The Linear Programming technique allowed to identify gaps that must be addressed by city managers to enhance actions taken. It also enabled to observe each municipal performance and compare results among similar municipalities.

Nondestructive Evaluation for Aerospace Composites

NASA Technical Reports Server (NTRS)

Leckey, Cara; Cramer, Elliott; Perey, Daniel

2015-01-01

Nondestructive evaluation (NDE) techniques are important for enabling NASA's missions in space exploration and aeronautics. The expanded and continued use of composite materials for aerospace components and vehicles leads to a need for advanced NDE techniques capable of quantitatively characterizing damage in composites. Quantitative damage detection techniques help to ensure safety, reliability and durability of space and aeronautic vehicles. This presentation will give a broad outline of NASA's range of technical work and an overview of the NDE research performed in the Nondestructive Evaluation Sciences Branch at NASA Langley Research Center. The presentation will focus on ongoing research in the development of NDE techniques for composite materials and structures, including development of automated data processing tools to turn NDE data into quantitative location and sizing results. Composites focused NDE research in the areas of ultrasonics, thermography, X-ray computed tomography, and NDE modeling will be discussed.

Evaluation of thresholding techniques for segmenting scaffold images in tissue engineering

NASA Astrophysics Data System (ADS)

Rajagopalan, Srinivasan; Yaszemski, Michael J.; Robb, Richard A.

2004-05-01

Tissue engineering attempts to address the ever widening gap between the demand and supply of organ and tissue transplants using natural and biomimetic scaffolds. The regeneration of specific tissues aided by synthetic materials is dependent on the structural and morphometric properties of the scaffold. These properties can be derived non-destructively using quantitative analysis of high resolution microCT scans of scaffolds. Thresholding of the scanned images into polymeric and porous phase is central to the outcome of the subsequent structural and morphometric analysis. Visual thresholding of scaffolds produced using stochastic processes is inaccurate. Depending on the algorithmic assumptions made, automatic thresholding might also be inaccurate. Hence there is a need to analyze the performance of different techniques and propose alternate ones, if needed. This paper provides a quantitative comparison of different thresholding techniques for segmenting scaffold images. The thresholding algorithms examined include those that exploit spatial information, locally adaptive characteristics, histogram entropy information, histogram shape information, and clustering of gray-level information. The performance of different techniques was evaluated using established criteria, including misclassification error, edge mismatch, relative foreground error, and region non-uniformity. Algorithms that exploit local image characteristics seem to perform much better than those using global information.

A near-optimal low complexity sensor fusion technique for accurate indoor localization based on ultrasound time of arrival measurements from low-quality sensors

NASA Astrophysics Data System (ADS)

Mitilineos, Stelios A.; Argyreas, Nick D.; Thomopoulos, Stelios C. A.

2009-05-01

A fusion-based localization technique for location-based services in indoor environments is introduced herein, based on ultrasound time-of-arrival measurements from multiple off-the-shelf range estimating sensors which are used in a market-available localization system. In-situ field measurements results indicated that the respective off-the-shelf system was unable to estimate position in most of the cases, while the underlying sensors are of low-quality and yield highly inaccurate range and position estimates. An extensive analysis is performed and a model of the sensor-performance characteristics is established. A low-complexity but accurate sensor fusion and localization technique is then developed, which consists inof evaluating multiple sensor measurements and selecting the one that is considered most-accurate based on the underlying sensor model. Optimality, in the sense of a genie selecting the optimum sensor, is subsequently evaluated and compared to the proposed technique. The experimental results indicate that the proposed fusion method exhibits near-optimal performance and, albeit being theoretically suboptimal, it largely overcomes most flaws of the underlying single-sensor system resulting in a localization system of increased accuracy, robustness and availability.

Speckle noise reduction in ultrasound images using a discrete wavelet transform-based image fusion technique.

PubMed

Choi, Hyun Ho; Lee, Ju Hwan; Kim, Sung Min; Park, Sung Yun

2015-01-01

Here, the speckle noise in ultrasonic images is removed using an image fusion-based denoising method. To optimize the denoising performance, each discrete wavelet transform (DWT) and filtering technique was analyzed and compared. In addition, the performances were compared in order to derive the optimal input conditions. To evaluate the speckle noise removal performance, an image fusion algorithm was applied to the ultrasound images, and comparatively analyzed with the original image without the algorithm. As a result, applying DWT and filtering techniques caused information loss and noise characteristics, and did not represent the most significant noise reduction performance. Conversely, an image fusion method applying SRAD-original conditions preserved the key information in the original image, and the speckle noise was removed. Based on such characteristics, the input conditions of SRAD-original had the best denoising performance with the ultrasound images. From this study, the best denoising technique proposed based on the results was confirmed to have a high potential for clinical application.

Advanced Video Analysis Needs for Human Performance Evaluation

NASA Technical Reports Server (NTRS)

Campbell, Paul D.

1994-01-01

Evaluators of human task performance in space missions make use of video as a primary source of data. Extraction of relevant human performance information from video is often a labor-intensive process requiring a large amount of time on the part of the evaluator. Based on the experiences of several human performance evaluators, needs were defined for advanced tools which could aid in the analysis of video data from space missions. Such tools should increase the efficiency with which useful information is retrieved from large quantities of raw video. They should also provide the evaluator with new analytical functions which are not present in currently used methods. Video analysis tools based on the needs defined by this study would also have uses in U.S. industry and education. Evaluation of human performance from video data can be a valuable technique in many industrial and institutional settings where humans are involved in operational systems and processes.

BIOMARKER ASSAYS IN NIPPLE APIRATE FLUID

EPA Science Inventory

ABSTRACT

The noninvasive technique of nipple aspiration as a potential source of biomarkers of breast cancer risk was evaluated. The feasibility of performing mutagenesis assays, amplifying DNA and performing protein electrophoresis on nipple aspirate fluid was explored. ...

Performance Analyses of Intercity Ground Passenger Transportation Systems

DOT National Transportation Integrated Search

1976-04-01

This report documents the development of analytical techniques and their use for investigating the performance of intercity ground passenger transportation systems. The purpose of the study is twofold: (1) to provide a capability of evaluating new pa...

A simplified flight-test method for determining aircraft takeoff performance that includes effects of pilot technique

NASA Technical Reports Server (NTRS)

Larson, T. J.; Schweikhard, W. G.

1974-01-01

A method for evaluating aircraft takeoff performance from brake release to air-phase height that requires fewer tests than conventionally required is evaluated with data for the XB-70 airplane. The method defines the effects of pilot technique on takeoff performance quantitatively, including the decrease in acceleration from drag due to lift. For a given takeoff weight and throttle setting, a single takeoff provides enough data to establish a standardizing relationship for the distance from brake release to any point where velocity is appropriate to rotation. The lower rotation rates penalized takeoff performance in terms of ground roll distance; the lowest observed rotation rate required a ground roll distance that was 19 percent longer than the highest. Rotations at the minimum rate also resulted in lift-off velocities that were approximately 5 knots lower than the highest rotation rate at any given lift-off distance.

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.

A histogram-based technique for rapid vector extraction from PIV photographs

NASA Technical Reports Server (NTRS)

Humphreys, William M., Jr.

1991-01-01

A new analysis technique, performed totally in the image plane, is proposed which rapidly extracts all available vectors from individual interrogation regions on PIV photographs. The technique avoids the need for using Fourier transforms with the associated computational burden. The data acquisition and analysis procedure is described, and results of a preliminary simulation study to evaluate the accuracy of the technique are presented. Recently obtained PIV photographs are analyzed.

An Integrated Calibration Technique for Stereo Vision Systems (PREPRINT)

DTIC Science & Technology

2010-03-01

technique for stereo vision systems has been developed. To demonstrate and evaluate this calibration technique, multiple Wii Remotes (Wiimotes) from Nintendo ...from Nintendo were used to form stereo vision systems to perform 3D motion capture in real time. This integrated technique is a two-step process...Wiimotes) used in Nintendo Wii games. Many researchers have successfully dealt with the problem of camera calibration by taking images from a 2D

Study of Adaptive Mathematical Models for Deriving Automated Pilot Performance Measurement Techniques. Volume II. Appendices. Final Report.

ERIC Educational Resources Information Center

Connelly, E. M.; And Others

A new approach to deriving human performance measures and criteria for use in automatically evaluating trainee performance is described. Ultimately, this approach will allow automatic measurement of pilot performance in a flight simulator or from recorded in-flight data. An efficient method of representing performance data within a computer is…

Evaluation and management of gunshot wounds of the penis: 20-year experience at an urban trauma center.

PubMed

Kunkle, David A; Lebed, Brett D; Mydlo, Jack H; Pontari, Michel A

2008-04-01

Although gunshot injuries to the penis occur relatively infrequently in patients with penetrating trauma, they often present dilemmas of subsequent evaluation and management. We review our extensive experience with gunshot wounds to the penis at a high volume urban trauma center. The urologic trauma database was retrospectively reviewed to extract and compile information from the records of 63 patients treated for gunshot wounds to the penis. Data were accumulated for a 20-year period from 1985 to 2004 with regard to findings on physical examination, diagnostic evaluation, associated injuries, management, and outcome. We detail our technique of penile exploration and artificial erection in the management of these injuries. Penile gunshot wounds were associated with additional injuries in 53 of 63 (84%) patients. A total of 48 (76%) patients were taken to the operating room and 44 (70%) penile explorations were performed. Evaluation included retrograde urethrogram in 50 of 63 (79%) patients and was diagnostic for urethral injury in 11 of 12 (92%) cases. Primary urethral repair was performed in 8 of 12 (67%) patients with urethral injury versus 4 of 12 (33%) who underwent urinary diversion by means of suprapubic cystotomy. Evaluation and management of gunshot wounds to the penis may potentially be complex. Retrograde urethrogram should be performed in all cases except the most insignificant and superficial wounds. We describe our technique of penile exploration and artificial erection, noting excellent results in patients for whom follow-up is available. Additional studies are needed to prospectively evaluate techniques for management of gunshot urethral injuries.

24 CFR 203.605 - Loss mitigation performance.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Loss mitigation performance. 203....605 Loss mitigation performance. (a) Duty to mitigate. Before four full monthly installments due on... mitigation techniques provided at § 203.501 to determine which is appropriate. Based upon such evaluations...

24 CFR 203.605 - Loss mitigation performance.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Loss mitigation performance. 203....605 Loss mitigation performance. (a) Duty to mitigate. Before four full monthly installments due on... mitigation techniques provided at § 203.501 to determine which is appropriate. Based upon such evaluations...

24 CFR 203.605 - Loss mitigation performance.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Loss mitigation performance. 203....605 Loss mitigation performance. (a) Duty to mitigate. Before four full monthly installments due on... mitigation techniques provided at § 203.501 to determine which is appropriate. Based upon such evaluations...

24 CFR 203.605 - Loss mitigation performance.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Loss mitigation performance. 203....605 Loss mitigation performance. (a) Duty to mitigate. Before four full monthly installments due on... mitigation techniques provided at § 203.501 to determine which is appropriate. Based upon such evaluations...

Adhesive and Cohesive Strength in FeB/Fe2B Systems

NASA Astrophysics Data System (ADS)

Meneses-Amador, A.; Blancas-Pérez, D.; Corpus-Mejía, R.; Rodríguez-Castro, G. A.; Martínez-Trinidad, J.; Jiménez-Tinoco, L. F.

2018-05-01

In this work, FeB/Fe2B systems were evaluated by the scratch test. The powder-pack boriding process was performed on the surface of AISI M2 steel. The mechanical parameters, such as yield stress and Young's modulus of the boride layer, were obtained by the instrumented indentation technique. Residual stresses produced on the boride layer were estimated by using the x-ray diffraction (XRD) technique. The scratch test was performed in order to evaluate the cohesive/adhesive strength of the FeB/Fe2B coating. In addition, a numerical evaluation of the scratch test on boride layers was performed by the finite element method. Maximum principal stresses were related to the failure mechanisms observed by the experimental scratch test. Shear stresses at the interfaces of the FeB/Fe2B/substrate system were also evaluated. Finally, the results obtained provide essential information about the effect of the layer thickness, the residual stresses, and the resilience modulus on the cohesive/adhesive strength in FeB/Fe2B systems.

A novel hybrid MCDM model for performance evaluation of research and technology organizations based on BSC approach.

PubMed

Varmazyar, Mohsen; Dehghanbaghi, Maryam; Afkhami, Mehdi

2016-10-01

Balanced Scorecard (BSC) is a strategic evaluation tool using both financial and non-financial indicators to determine the business performance of organizations or companies. In this paper, a new integrated approach based on the Balanced Scorecard (BSC) and multi-criteria decision making (MCDM) methods are proposed to evaluate the performance of research centers of research and technology organization (RTO) in Iran. Decision-Making Trial and Evaluation Laboratory (DEMATEL) are employed to reflect the interdependencies among BSC perspectives. Then, Analytic Network Process (ANP) is utilized to weight the indices influencing the considered problem. In the next step, we apply four MCDM methods including Additive Ratio Assessment (ARAS), Complex Proportional Assessment (COPRAS), Multi-Objective Optimization by Ratio Analysis (MOORA), and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) for ranking of alternatives. Finally, the utility interval technique is applied to combine the ranking results of MCDM methods. Weighted utility intervals are computed by constructing a correlation matrix between the ranking methods. A real case is presented to show the efficacy of the proposed approach. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transit Station Renovation: A Case Study of Planning and Design Procedures

DOT National Transportation Integrated Search

1979-06-01

The general techniques and procedures for planning and evaluating transit : interface facilities are applied comprehensively to the problem of station : renovation. The 69th Street Terminal in Philadelphia is evaluated in terms of : its performance i...

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.

Application of thrusting ejectors to tactical aircraft having vertical lift and short-field capability

NASA Technical Reports Server (NTRS)

Koenig, D. G.; Stoll, F.; Aoyagi, K.

1981-01-01

The status of ejector development in terms of application to V/STOL aircraft is reported in three categories: aircraft systems and ejector concepts; ejector performance including prediction techniques and experimental data base available; and, integration of the ejector with complete aircraft configurations. Available prediction techniques are reviewed and performance of three ejector designs with vertical lift capability is summarized. Applications of the 'fuselage' and 'short diffuser' ejectors to fighter aircraft are related to current and planned research programs. Recommendations are listed for effort needed to evaluate installed performance.

Development and validation of a sensor-based health monitoring model for the Parkview Bridge deck : [appendices].

DOT National Transportation Integrated Search

2012-01-31

Accelerated bridge construction (ABC) using full-depth precast deck panels is an innovative technique that brings all the benefits listed under ABC to full fruition. However, this technique needs to be evaluated and the performance of the bridge need...

Post-processing techniques to enhance reliability of assignment algorithm based performance measures : [technical summary].

DOT National Transportation Integrated Search

2011-01-01

Travel demand modeling plays a key role in the transportation system planning and evaluation process. The four-step sequential travel demand model is the most widely used technique in practice. Traffic assignment is the key step in the conventional f...

Carrier recovery techniques on satellite mobile channels

NASA Technical Reports Server (NTRS)

Vucetic, B.; Du, J.

1990-01-01

An analytical method and a stored channel model were used to evaluate error performance of uncoded quadrature phase shift keying (QPSK) and M-ary phase shift keying (MPSK) trellis coded modulation (TCM) over shadowed satellite mobile channels in the presence of phase jitter for various carrier recovery techniques.

Evaluation of traction stirrup distraction technique to increase the joint space of the shoulder joint in the dog: A cadaveric study.

PubMed

Devesa, V; Rovesti, G L; Urrutia, P G; Sanroman, F; Rodriguez-Quiros, J

2015-06-01

The objective of this study was to evaluate technical feasibility and efficacy of a joint distraction technique by traction stirrup to facilitate shoulder arthroscopy and assess potential soft tissue damage. Twenty shoulders were evaluated radiographically before distraction. Distraction was applied with loads from 40 N up to 200 N, in 40 N increments, and the joint space was recorded at each step by radiographic images. The effects of joint flexion and intra-articular air injection at maximum load were evaluated. Radiographic evaluation was performed after distraction to evaluate ensuing joint laxity. Joint distraction by traction stirrup technique produces a significant increase in the joint space; an increase in joint laxity could not be inferred by standard and stress radiographs. However, further clinical studies are required to evaluate potential neurovascular complications. A wider joint space may be useful to facilitate arthroscopy, reducing the likelihood for iatrogenic damage to intra-articular structures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Smart Sampling and HPC-based Probabilistic Look-ahead Contingency Analysis Implementation and its Evaluation with Real-world Data

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

Chen, Yousu; Etingov, Pavel V.; Ren, Huiying

This paper describes a probabilistic look-ahead contingency analysis application that incorporates smart sampling and high-performance computing (HPC) techniques. Smart sampling techniques are implemented to effectively represent the structure and statistical characteristics of uncertainty introduced by different sources in the power system. They can significantly reduce the data set size required for multiple look-ahead contingency analyses, and therefore reduce the time required to compute them. High-performance-computing (HPC) techniques are used to further reduce computational time. These two techniques enable a predictive capability that forecasts the impact of various uncertainties on potential transmission limit violations. The developed package has been tested withmore » real world data from the Bonneville Power Administration. Case study results are presented to demonstrate the performance of the applications developed.« less

One way Doppler extractor. Volume 1: Vernier technique

NASA Technical Reports Server (NTRS)

Blasco, R. W.; Klein, S.; Nossen, E. J.; Starner, E. R.; Yanosov, J. A.

1974-01-01

A feasibility analysis, trade-offs, and implementation for a One Way Doppler Extraction system are discussed. A Doppler error analysis shows that quantization error is a primary source of Doppler measurement error. Several competing extraction techniques are compared and a Vernier technique is developed which obtains high Doppler resolution with low speed logic. Parameter trade-offs and sensitivities for the Vernier technique are analyzed, leading to a hardware design configuration. A detailed design, operation, and performance evaluation of the resulting breadboard model is presented which verifies the theoretical performance predictions. Performance tests have verified that the breadboard is capable of extracting Doppler, on an S-band signal, to an accuracy of less than 0.02 Hertz for a one second averaging period. This corresponds to a range rate error of no more than 3 millimeters per second.

MEASUREMENT OF NATURAL RADIONUCLIDES AND EXTERNAL RADIATION EXPOSURE DUE TO FLY ASH FROM A COAL-FIRED POWER PLANT (SPAIN) DEPOSITED ON SOILS. COMPARISON USING TWO DIFFERENT MEASUREMENT TECHNIQUES.

PubMed

Corbacho, J A; Baeza, A

2018-05-17

The evaluation of the radiological impact in soils due to the fly-ash ponds using both in situ techniques and laboratory based measurements is presented. In order to check the in situ techniques capabilities for monitoring this type of industries, a comparison between both techniques was performed. A characterization of external radiation exposure in the fly-ash pond and in its surrounding soils was made. The associated external radiological hazard due to the fly-ash pond has been evaluated. In situ techniques could be used to determine the radiological impact on soils due to fly-ash deposition, but its use could be limited due to the associated uncertainties.

Performance of protective coatings on structural plate pipe arches.

DOT National Transportation Integrated Search

1978-01-01

The performance of bituminous coatings on structural plate pipe and pipe arches was evaluated in a limited field study supplemented by a survey of information from other agencies. Of the two available application techniques, immersion of individual p...

Evaluation of a technique to simplify area navigation and required navigation performance charts

DOT National Transportation Integrated Search

2013-06-30

Performance based navigation (PBN), an enabler for the Federal Aviation Administration's Next Generation Air Transportation System (NextGEN), supports the design of more precise flight procedures. However, these new procedures can be visually complex...

Evaluation of performance of asphalt pavements constructed using intelligent compaction techniques.

DOT National Transportation Integrated Search

2014-10-01

The long-term performance of asphalt pavements depends on the quality of the subgrade and : asphalt layers. Intelligent compaction methods continuously monitor the modulus/stiffness of : subgrade and asphalt layers during compaction process and have ...

Robust human machine interface based on head movements applied to assistive robotics.

PubMed

Perez, Elisa; López, Natalia; Orosco, Eugenio; Soria, Carlos; Mut, Vicente; Freire-Bastos, Teodiano

2013-01-01

This paper presents an interface that uses two different sensing techniques and combines both results through a fusion process to obtain the minimum-variance estimator of the orientation of the user's head. Sensing techniques of the interface are based on an inertial sensor and artificial vision. The orientation of the user's head is used to steer the navigation of a robotic wheelchair. Also, a control algorithm for assistive technology system is presented. The system is evaluated by four individuals with severe motors disability and a quantitative index was developed, in order to objectively evaluate the performance. The results obtained are promising since most users could perform the proposed tasks with the robotic wheelchair.

Robust Human Machine Interface Based on Head Movements Applied to Assistive Robotics

PubMed Central

Perez, Elisa; López, Natalia; Orosco, Eugenio; Soria, Carlos; Mut, Vicente; Freire-Bastos, Teodiano

2013-01-01

This paper presents an interface that uses two different sensing techniques and combines both results through a fusion process to obtain the minimum-variance estimator of the orientation of the user's head. Sensing techniques of the interface are based on an inertial sensor and artificial vision. The orientation of the user's head is used to steer the navigation of a robotic wheelchair. Also, a control algorithm for assistive technology system is presented. The system is evaluated by four individuals with severe motors disability and a quantitative index was developed, in order to objectively evaluate the performance. The results obtained are promising since most users could perform the proposed tasks with the robotic wheelchair. PMID:24453877

Low Earth orbit atomic oxygen simulation for durability evaluation of solar reflector surfaces

NASA Technical Reports Server (NTRS)

Degroh, Kim K.; Banks, Bruce A.

1992-01-01

To evaluate the performance and durability of solar reflector surfaces in the atomic oxygen environment typical of low Earth orbit (LEO), one must expose the reflector surface either directly to LEO or to ground-laboratory atomic oxygen environments. Although actual LEO exposures are most desired, such opportunities are typically scarce, expensive, and of limited duration. As a result, ground-laboratory exposures must be relied upon as the most practical long-term durability evaluation technique. Plasma ashers are widely used as LEO simulation facilities by producing atomic oxygen environments for durability evaluation of potential spacecraft materials. Atomic oxygen arrival differs between ground and space exposure in that plasma asher exposure produces isotropic arrival and space solar tracking produces sweeping arrival. Differences in initial impact reaction probability occur, dependent upon the energy and species existing in these environments. Due to the variations in ground-laboratory and space atomic oxygen, quantification of in-space performance based on plasma asher testing is not straightforward. The various atomic oxygen interactions that can occur with reflector surfaces, such as undercutting in organic substrates at protective coating defect sites, ground-laboratory techniques recommended for evaluating the atomic oxygen durability of reflectors based on asher exposures, and computational techniques which make use of ground-laboratory atomic oxygen exposure to predict in-space LEO durability are addressed.

Evaluation of Data Processing Techniques for Unobtrusive Gait Authentication

DTIC Science & Technology

2014-03-01

scatter plot depicting the performance of kNN , by TER, on all experimental mixtures...30  Table 9.  Mean TER of SVM and kNN performance with different voting parameters...performance on XYZ-axis data. ...........................................................51  Table 19.  kNN and SVM results in back pocket carrying

Endovascular treatment of wide-neck intracranial aneurysms using a microcatheter protective technique: results and outcomes in 75 aneurysms.

PubMed

Lee, J Y; Seo, J H; Cho, Y D; Kang, H-S; Han, M H

2011-05-01

The microcatheter protective technique positions an additional microcatheter in the parent or side-branching artery to protect it during coil embolization. The purpose of this study was to describe this method and to evaluate its efficacy and safety as an alternative to a multiple-microcatheter or balloon- or stent-assisted technique for wide-neck aneurysms. A retrospective review of 74 patients (43 women; mean age, 59.6 years) with 75 wide-neck aneurysms treated with the microcatheter protective technique between January 2003 and April 2010 was performed. Immediate postembolization angiograms were evaluated by using a conventional angiographic scale, and clinical evaluation was performed by using the GOS. Clinical and imaging follow-up were available in 57 (76%) patients, with a mean of 14.7 months. Postembolization angiograms demonstrated total occlusion in 45 of 75 (60%) aneurysms, a neck remnant in 17 (22.7%), and body filling in 13 (17.3%). The technique-related complication rate was 17.4% (13/75), and the procedural-related morbidity rate was 1.3% (1/74). All patients, except 3 complicated cases with a GOS of <4, had a GOS of 5 at the end of the study period. Of the 57 aneurysms with follow-up, recanalization developed in 5 (8.8%) aneurysms, and 3 (5.3%) cases of major recanalization were re-treated endovascularly. The microcatheter protective technique is feasible and safe for coil embolization of wide-neck aneurysms, especially in cases that are not suitable for multiple catheter or balloon- or stent-assisted techniques.

Daily pan evaporation modelling using a neuro-fuzzy computing technique

NASA Astrophysics Data System (ADS)

Kişi, Özgür

2006-10-01

SummaryEvaporation, as a major component of the hydrologic cycle, is important in water resources development and management. This paper investigates the abilities of neuro-fuzzy (NF) technique to improve the accuracy of daily evaporation estimation. Five different NF models comprising various combinations of daily climatic variables, that is, air temperature, solar radiation, wind speed, pressure and humidity are developed to evaluate degree of effect of each of these variables on evaporation. A comparison is made between the estimates provided by the NF model and the artificial neural networks (ANNs). The Stephens-Stewart (SS) method is also considered for the comparison. Various statistic measures are used to evaluate the performance of the models. Based on the comparisons, it was found that the NF computing technique could be employed successfully in modelling evaporation process from the available climatic data. The ANN also found to perform better than the SS method.

An image compression survey and algorithm switching based on scene activity

NASA Technical Reports Server (NTRS)

Hart, M. M.

1985-01-01

Data compression techniques are presented. A description of these techniques is provided along with a performance evaluation. The complexity of the hardware resulting from their implementation is also addressed. The compression effect on channel distortion and the applicability of these algorithms to real-time processing are presented. Also included is a proposed new direction for an adaptive compression technique for real-time processing.

Peak-to-average power ratio reduction in orthogonal frequency division multiplexing-based visible light communication systems using a modified partial transmit sequence technique

NASA Astrophysics Data System (ADS)

Liu, Yan; Deng, Honggui; Ren, Shuang; Tang, Chengying; Qian, Xuewen

2018-01-01

We propose an efficient partial transmit sequence technique based on genetic algorithm and peak-value optimization algorithm (GAPOA) to reduce high peak-to-average power ratio (PAPR) in visible light communication systems based on orthogonal frequency division multiplexing (VLC-OFDM). By analysis of hill-climbing algorithm's pros and cons, we propose the POA with excellent local search ability to further process the signals whose PAPR is still over the threshold after processed by genetic algorithm (GA). To verify the effectiveness of the proposed technique and algorithm, we evaluate the PAPR performance and the bit error rate (BER) performance and compare them with partial transmit sequence (PTS) technique based on GA (GA-PTS), PTS technique based on genetic and hill-climbing algorithm (GH-PTS), and PTS based on shuffled frog leaping algorithm and hill-climbing algorithm (SFLAHC-PTS). The results show that our technique and algorithm have not only better PAPR performance but also lower computational complexity and BER than GA-PTS, GH-PTS, and SFLAHC-PTS technique.

Evaluating the sources of water to wells: Three techniques for metamodeling of a groundwater flow model

USGS Publications Warehouse

Fienen, Michael N.; Nolan, Bernard T.; Feinstein, Daniel T.

2016-01-01

For decision support, the insights and predictive power of numerical process models can be hampered by insufficient expertise and computational resources required to evaluate system response to new stresses. An alternative is to emulate the process model with a statistical “metamodel.” Built on a dataset of collocated numerical model input and output, a groundwater flow model was emulated using a Bayesian Network, an Artificial neural network, and a Gradient Boosted Regression Tree. The response of interest was surface water depletion expressed as the source of water-to-wells. The results have application for managing allocation of groundwater. Each technique was tuned using cross validation and further evaluated using a held-out dataset. A numerical MODFLOW-USG model of the Lake Michigan Basin, USA, was used for the evaluation. The performance and interpretability of each technique was compared pointing to advantages of each technique. The metamodel can extend to unmodeled areas.

Numerical evaluation of the radiation from unbaffled, finite plates using the FFT

NASA Technical Reports Server (NTRS)

Williams, E. G.

1983-01-01

An iteration technique is described which numerically evaluates the acoustic pressure and velocity on and near unbaffled, finite, thin plates vibrating in air. The technique is based on Rayleigh's integral formula and its inverse. These formulas are written in their angular spectrum form so that the fast Fourier transform (FFT) algorithm may be used to evaluate them. As an example of the technique the pressure on the surface of a vibrating, unbaffled disk is computed and shown to be in excellent agreement with the exact solution using oblate spheroidal functions. Furthermore, the computed velocity field outside the disk shows the well-known singularity at the rim of the disk. The radiated fields from unbaffled flat sources of any geometry with prescribed surface velocity may be evaluated using this technique. The use of the FFT to perform the integrations in Rayleigh's formulas provides a great savings in computation time compared with standard integration algorithms, especially when an array processor can be used to implement the FFT.

Application of imaging techniques to evaluate polishing characteristics of aggregates : final report.

DOT National Transportation Integrated Search

2016-12-01

Previous research conducted at the University of Florida (UF) to investigate the use of the Aggregate Image Measurement System (AIMS) and Micro-Deval (MD) to evaluate frictional performance of aggregates concluded that the current AIMS system cannot ...

Laboratory evaluation of alcohol safety interlock systems. Volume 3 : instrument performance at high BAL

DOT National Transportation Integrated Search

1974-01-01

This report contains the results of an experimental and analytical evaluation of instruments and techniques designed to prevent an intoxicated driver from operating his automobile. The prototype 'Alcohol Safety Interlock Systems' tested were develope...

Techniques for obtaining subjective response to vertical vibration

NASA Technical Reports Server (NTRS)

Clarke, M. J.; Oborne, D. J.

1975-01-01

Laboratory experiments were performed to validate the techniques used for obtaining ratings in the field surveys carried out by the University College of Swansea. In addition, attempts were made to evaluate the basic form of the human response to vibration. Some of the results obtained by different methods are described.

Evaluating motion processing algorithms for use with functional near-infrared spectroscopy data from young children.

PubMed

Delgado Reyes, Lourdes M; Bohache, Kevin; Wijeakumar, Sobanawartiny; Spencer, John P

2018-04-01

Motion artifacts are often a significant component of the measured signal in functional near-infrared spectroscopy (fNIRS) experiments. A variety of methods have been proposed to address this issue, including principal components analysis (PCA), correlation-based signal improvement (CBSI), wavelet filtering, and spline interpolation. The efficacy of these techniques has been compared using simulated data; however, our understanding of how these techniques fare when dealing with task-based cognitive data is limited. Brigadoi et al. compared motion correction techniques in a sample of adult data measured during a simple cognitive task. Wavelet filtering showed the most promise as an optimal technique for motion correction. Given that fNIRS is often used with infants and young children, it is critical to evaluate the effectiveness of motion correction techniques directly with data from these age groups. This study addresses that problem by evaluating motion correction algorithms implemented in HomER2. The efficacy of each technique was compared quantitatively using objective metrics related to the physiological properties of the hemodynamic response. Results showed that targeted PCA (tPCA), spline, and CBSI retained a higher number of trials. These techniques also performed well in direct head-to-head comparisons with the other approaches using quantitative metrics. The CBSI method corrected many of the artifacts present in our data; however, this approach produced sometimes unstable HRFs. The targeted PCA and spline methods proved to be the most robust, performing well across all comparison metrics. When compared head to head, tPCA consistently outperformed spline. We conclude, therefore, that tPCA is an effective technique for correcting motion artifacts in fNIRS data from young children.

Application of a novel new multispectral nanoparticle tracking technique

NASA Astrophysics Data System (ADS)

McElfresh, Cameron; Harrington, Tyler; Vecchio, Kenneth S.

2018-06-01

Fast, reliable, and accurate particle size analysis techniques must meet the demands of evolving industrial and academic research in areas of functionalized nanoparticle synthesis, advanced materials development, and other nanoscale enabled technologies. In this study a new multispectral particle tracking analysis (m-PTA) technique enabled by the ViewSizer™ 3000 (MANTA Instruments, USA) was evaluated using solutions of monomodal and multimodal gold and polystyrene latex nanoparticles, as well as a spark eroded polydisperse 316L stainless steel nanopowder, and large (non-Brownian) borosilicate particles. It was found that m-PTA performed comparably to the DLS in evaluation of monomodal particle size distributions. When measuring bimodal, trimodal and polydisperse solutions, the m-PTA technique overwhelmingly outperformed traditional dynamic light scattering (DLS) in both peak detection and relative particle concentration analysis. It was also observed that the m-PTA technique is less susceptible to large particle overexpression errors. The ViewSizer™ 3000 was also found to be successful in accurately evaluating sizes and concentrations of monomodal and bimodal sinking borosilicate particles.

Instrument performance of a radon measuring system with the alpha-track detection technique.

PubMed

Tokonami, S; Zhuo, W; Ryuo, H; Yonehara, H; Yamada, Y; Shimo, M

2003-01-01

An instrument performance test has been carried out for a radon measuring system made in Hungary. The system measures radon using the alpha-track detection technique. It consists of three parts: the passive detector, the etching unit and the evaluation unit. A CR-39 detector is used as the radiation detector. Alpha-track reading and data analysis are carried out after chemical etching. The following subjects were examined in the present study: (1) radon sensitivity, (2) performance of etching and evaluation processes and (3) thoron sensitivity. The radon sensitivity of 6.9 x 10(-4) mm(-2) (Bq m(-3) d)(-1) was acceptable for practical application. The thoron sensitivity was estimated to be as low as 3.3 x 10(-5) mm(-2) (Bq m(-3) d)(-1) from the experimental study.

Evaluation of image features and classification methods for Barrett's cancer detection using VLE imaging

NASA Astrophysics Data System (ADS)

Klomp, Sander; van der Sommen, Fons; Swager, Anne-Fré; Zinger, Svitlana; Schoon, Erik J.; Curvers, Wouter L.; Bergman, Jacques J.; de With, Peter H. N.

2017-03-01

Volumetric Laser Endomicroscopy (VLE) is a promising technique for the detection of early neoplasia in Barrett's Esophagus (BE). VLE generates hundreds of high resolution, grayscale, cross-sectional images of the esophagus. However, at present, classifying these images is a time consuming and cumbersome effort performed by an expert using a clinical prediction model. This paper explores the feasibility of using computer vision techniques to accurately predict the presence of dysplastic tissue in VLE BE images. Our contribution is threefold. First, a benchmarking is performed for widely applied machine learning techniques and feature extraction methods. Second, three new features based on the clinical detection model are proposed, having superior classification accuracy and speed, compared to earlier work. Third, we evaluate automated parameter tuning by applying simple grid search and feature selection methods. The results are evaluated on a clinically validated dataset of 30 dysplastic and 30 non-dysplastic VLE images. Optimal classification accuracy is obtained by applying a support vector machine and using our modified Haralick features and optimal image cropping, obtaining an area under the receiver operating characteristic of 0.95 compared to the clinical prediction model at 0.81. Optimal execution time is achieved using a proposed mean and median feature, which is extracted at least factor 2.5 faster than alternative features with comparable performance.

Study of Adaptive Mathematical Models for Deriving Automated Pilot Performance Measurement Techniques. Volume I. Model Development.

ERIC Educational Resources Information Center

Connelly, Edward A.; And Others

A new approach to deriving human performance measures and criteria for use in automatically evaluating trainee performance is documented in this report. The ultimate application of the research is to provide methods for automatically measuring pilot performance in a flight simulator or from recorded in-flight data. An efficient method of…

Operator performance evaluation using multi criteria decision making methods

NASA Astrophysics Data System (ADS)

Rani, Ruzanita Mat; Ismail, Wan Rosmanira; Razali, Siti Fatihah

2014-06-01

Operator performance evaluation is a very important operation in labor-intensive manufacturing industry because the company's productivity depends on the performance of its operators. The aims of operator performance evaluation are to give feedback to operators on their performance, to increase company's productivity and to identify strengths and weaknesses of each operator. In this paper, six multi criteria decision making methods; Analytical Hierarchy Process (AHP), fuzzy AHP (FAHP), ELECTRE, PROMETHEE II, Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) are used to evaluate the operators' performance and to rank the operators. The performance evaluation is based on six main criteria; competency, experience and skill, teamwork and time punctuality, personal characteristics, capability and outcome. The study was conducted at one of the SME food manufacturing companies in Selangor. From the study, it is found that AHP and FAHP yielded the "outcome" criteria as the most important criteria. The results of operator performance evaluation showed that the same operator is ranked the first using all six methods.

Nondestructive evaluation of oriented strand board exposed to decay fungi.

Treesearch

Barbara L. Illman; Vina W. Yang; Robert J. Ross; William J. Nelson

2002-01-01

Stress wave nondestructive evaluation (NDE) technologies are being used in our laboratory to evaluate the performance properties of engineered wood. These techniques have proven useful in the inspection of timber structures to locate internal voids and decayed or deteriorated areas in large timbers. But no information exists concerning NDE and important properties of...

Analysis of Questionnaires Applied in the Evaluation Process of Academicians in Higher Education Institutes

ERIC Educational Resources Information Center

Kalayci, Nurdan; Cimen, Orhan

2012-01-01

The aim of this study is to examine the questionnaires used to evaluate teaching performance in higher education institutes and called "Instructor and Course Evaluation Questionnaires (ICEQ)" in terms of questionnaire preparation techniques and components of curriculum. Obtaining at least one ICEQ belonging to any state and private…

Autonomic Evaluation of Patients With Gastroparesis and Neurostimulation: Comparisons of Direct/Systemic and Indirect/Cardiac Measures

PubMed Central

Stocker, Abigail; Abell, Thomas L.; Rashed, Hani; Kedar, Archana; Boatright, Ben; Chen, Jiande

2016-01-01

Background Disorders of nausea, vomiting, abdominal pain, and related problems often are manifestations of gastrointestinal, neuromuscular, and/or autonomic dysfunction. Many of these patients respond to neurostimulation, either gastric electrical stimulation or electroacupuncture. Both of these therapeutic techniques appear to influence the autonomic nervous system which can be evaluated directly by traditional testing and indirectly by heart rate variability. Methods We studied patients undergoing gastric neuromodulation by both systemic autonomic testing (39 patients, six males and 33 females, mean age 38 years) and systemic autonomic testing and heart rate variability (35 patients, seven males and 28 females, mean age 37 years) testing before and after gastric neuromodulation. We also performed a pilot study using both systemic autonomic testing and heart rate variability in a small number of patients (five patients, all females, mean age 48.6 years) with diabetic gastroparesis at baseline to compare the two techniques at baseline. Systemic autonomic testing and heart rate variability were performed with standardized techniques and gastric electrical stimulation was performed as previously described with electrodes implanted serosally in the myenteric plexus. Results Both systemic autonomic testing and heart rate variability measures were often abnormal at baseline and showed changes after gastric neuromodulation therapy in two groups of symptomatic patients. Pilot data on a small group of similar patients with systemic automatic nervous measures and heart rate variability showed good concordance between the two techniques. Conclusions Both traditional direct autonomic measures and indirect measures such as heart rate variability were evaluated, including a pilot study of both methods in the same patient group. Both appear to be useful in evaluation of patients at baseline and after stimulation therapies; however, a future full head-to-head comparison is warranted. PMID:27785318

Performance evaluation of the RITG148+ set of TomoTherapy quality assurance tools using RTQA2 radiochromic film.

PubMed

Lobb, Eric C

2016-07-08

Version 6.3 of the RITG148+ software package offers eight automated analysis routines for quality assurance of the TomoTherapy platform. A performance evaluation of each routine was performed in order to compare RITG148+ results with traditionally accepted analysis techniques and verify that simulated changes in machine parameters are correctly identified by the software. Reference films were exposed according to AAPM TG-148 methodology for each routine and the RITG148+ results were compared with either alternative software analysis techniques or manual analysis techniques in order to assess baseline agreement. Changes in machine performance were simulated through translational and rotational adjustments to subsequently irradiated films, and these films were analyzed to verify that the applied changes were accurately detected by each of the RITG148+ routines. For the Hounsfield unit routine, an assessment of the "Frame Averaging" functionality and the effects of phantom roll on the routine results are presented. All RITG148+ routines reported acceptable baseline results consistent with alternative analysis techniques, with 9 of the 11 baseline test results showing agreement of 0.1mm/0.1° or better. Simulated changes were correctly identified by the RITG148+ routines within approximately 0.2 mm/0.2° with the exception of the Field Centervs. Jaw Setting routine, which was found to have limited accuracy in cases where field centers were not aligned for all jaw settings due to inaccurate autorotation of the film during analysis. The performance of the RITG148+ software package was found to be acceptable for introduction into our clinical environment as an automated alternative to traditional analysis techniques for routine TomoTherapy quality assurance testing.

Artificial intelligence in sports on the example of weight training.

PubMed

Novatchkov, Hristo; Baca, Arnold

2013-01-01

The overall goal of the present study was to illustrate the potential of artificial intelligence (AI) techniques in sports on the example of weight training. The research focused in particular on the implementation of pattern recognition methods for the evaluation of performed exercises on training machines. The data acquisition was carried out using way and cable force sensors attached to various weight machines, thereby enabling the measurement of essential displacement and force determinants during training. On the basis of the gathered data, it was consequently possible to deduce other significant characteristics like time periods or movement velocities. These parameters were applied for the development of intelligent methods adapted from conventional machine learning concepts, allowing an automatic assessment of the exercise technique and providing individuals with appropriate feedback. In practice, the implementation of such techniques could be crucial for the investigation of the quality of the execution, the assistance of athletes but also coaches, the training optimization and for prevention purposes. For the current study, the data was based on measurements from 15 rather inexperienced participants, performing 3-5 sets of 10-12 repetitions on a leg press machine. The initially preprocessed data was used for the extraction of significant features, on which supervised modeling methods were applied. Professional trainers were involved in the assessment and classification processes by analyzing the video recorded executions. The so far obtained modeling results showed good performance and prediction outcomes, indicating the feasibility and potency of AI techniques in assessing performances on weight training equipment automatically and providing sportsmen with prompt advice. Key pointsArtificial intelligence is a promising field for sport-related analysis.Implementations integrating pattern recognition techniques enable the automatic evaluation of data measurements.Artificial neural networks applied for the analysis of weight training data show good performance and high classification rates.

Artificial Intelligence in Sports on the Example of Weight Training

PubMed Central

Novatchkov, Hristo; Baca, Arnold

2013-01-01

The overall goal of the present study was to illustrate the potential of artificial intelligence (AI) techniques in sports on the example of weight training. The research focused in particular on the implementation of pattern recognition methods for the evaluation of performed exercises on training machines. The data acquisition was carried out using way and cable force sensors attached to various weight machines, thereby enabling the measurement of essential displacement and force determinants during training. On the basis of the gathered data, it was consequently possible to deduce other significant characteristics like time periods or movement velocities. These parameters were applied for the development of intelligent methods adapted from conventional machine learning concepts, allowing an automatic assessment of the exercise technique and providing individuals with appropriate feedback. In practice, the implementation of such techniques could be crucial for the investigation of the quality of the execution, the assistance of athletes but also coaches, the training optimization and for prevention purposes. For the current study, the data was based on measurements from 15 rather inexperienced participants, performing 3-5 sets of 10-12 repetitions on a leg press machine. The initially preprocessed data was used for the extraction of significant features, on which supervised modeling methods were applied. Professional trainers were involved in the assessment and classification processes by analyzing the video recorded executions. The so far obtained modeling results showed good performance and prediction outcomes, indicating the feasibility and potency of AI techniques in assessing performances on weight training equipment automatically and providing sportsmen with prompt advice. Key points Artificial intelligence is a promising field for sport-related analysis. Implementations integrating pattern recognition techniques enable the automatic evaluation of data measurements. Artificial neural networks applied for the analysis of weight training data show good performance and high classification rates. PMID:24149722

Evaluation of a rule-based compositing technique for Landsat-5 TM and Landsat-7 ETM+ images

NASA Astrophysics Data System (ADS)

Lück, W.; van Niekerk, A.

2016-05-01

Image compositing is a multi-objective optimization process. Its goal is to produce a seamless cloud and artefact-free artificial image. This is achieved by aggregating image observations and by replacing poor and cloudy data with good observations from imagery acquired within the timeframe of interest. This compositing process aims to minimise the visual artefacts which could result from different radiometric properties, caused by atmospheric conditions, phenologic patterns and land cover changes. It has the following requirements: (1) image compositing must be cloud free, which requires the detection of clouds and shadows, and (2) the image composite must be seamless, minimizing artefacts and visible across inter image seams. This study proposes a new rule-based compositing technique (RBC) that combines the strengths of several existing methods. A quantitative and qualitative evaluation is made of the RBC technique by comparing it to the maximum NDVI (MaxNDVI), minimum red (MinRed) and maximum ratio (MaxRatio) compositing techniques. A total of 174 Landsat TM and ETM+ images, covering three study sites and three different timeframes for each site, are used in the evaluation. A new set of quantitative/qualitative evaluation techniques for compositing quality measurement was developed and showed that the RBC technique outperformed all other techniques, with MaxRatio, MaxNDVI, and MinRed techniques in order of performance from best to worst.

Comparison of dual and single exposure techniques in dual-energy chest radiography.

PubMed

Ho, J T; Kruger, R A; Sorenson, J A

1989-01-01

Conventional chest radiography is the most effective tool for lung cancer detection and diagnosis; nevertheless, a high percentage of lung cancer tumors are missed because of the overlap of lung nodule image contrast with bone image contrast in a chest radiograph. Two different energy subtraction strategies, dual exposure and single exposure techniques, were studied for decomposing a radiograph into bone-free and soft tissue-free images to address this problem. For comparing the efficiency of these two techniques in lung nodule detection, the performances of the techniques were evaluated on the basis of residual tissue contrast, energy separation, and signal-to-noise ratio. The evaluation was based on both computer simulation and experimental verification. The dual exposure technique was found to be better than the single exposure technique because of its higher signal-to-noise ratio and greater residual tissue contrast. However, x-ray tube loading and patient motion are problems.

Time-dependent inertia analysis of vehicle mechanisms

NASA Astrophysics Data System (ADS)

Salmon, James Lee

Two methods for performing transient inertia analysis of vehicle hardware systems are developed in this dissertation. The analysis techniques can be used to predict the response of vehicle mechanism systems to the accelerations associated with vehicle impacts. General analytical methods for evaluating translational or rotational system dynamics are generated and evaluated for various system characteristics. The utility of the derived techniques are demonstrated by applying the generalized methods to two vehicle systems. Time dependent acceleration measured during a vehicle to vehicle impact are used as input to perform a dynamic analysis of an automobile liftgate latch and outside door handle. Generalized Lagrange equations for a non-conservative system are used to formulate a second order nonlinear differential equation defining the response of the components to the transient input. The differential equation is solved by employing the fourth order Runge-Kutta method. The events are then analyzed using commercially available two dimensional rigid body dynamic analysis software. The results of the two analytical techniques are compared to experimental data generated by high speed film analysis of tests of the two components performed on a high G acceleration sled at Ford Motor Company.

Protective Coatings for Metals

NASA Technical Reports Server (NTRS)

Ruggieri, D. J.; Rowe, A. P.

1986-01-01

Report evaluates protective coatings for metal structures in seashore and acid-cloud environments. Evaluation result of study of coating application characteristics, repair techniques, and field performance. Products from variety of manufacturers included in study. Also factory-coated panels and industrial galvanized panels with and without topcoats.

Simulations of motor unit number estimation techniques

NASA Astrophysics Data System (ADS)

Major, Lora A.; Jones, Kelvin E.

2005-06-01

Motor unit number estimation (MUNE) is an electrodiagnostic procedure used to evaluate the number of motor axons connected to a muscle. All MUNE techniques rely on assumptions that must be fulfilled to produce a valid estimate. As there is no gold standard to compare the MUNE techniques against, we have developed a model of the relevant neuromuscular physiology and have used this model to simulate various MUNE techniques. The model allows for a quantitative analysis of candidate MUNE techniques that will hopefully contribute to consensus regarding a standard procedure for performing MUNE.

Performance Evaluation of Adaptive Imaging Based on Multiphase Apodization with Cross-correlation: A Pilot Study in Abdominal Ultrasound.

PubMed

Shin, Junseob; Chen, Yu; Malhi, Harshawn; Chen, Frank; Yen, Jesse

2018-05-01

Degradation of image contrast caused by phase aberration, off-axis clutter, and reverberation clutter remains one of the most important problems in abdominal ultrasound imaging. Multiphase apodization with cross-correlation (MPAX) is a novel beamforming technique that enhances ultrasound image contrast by adaptively suppressing unwanted acoustic clutter. MPAX employs multiple pairs of complementary sinusoidal phase apodizations to intentionally introduce grating lobes that can be used to derive a weighting matrix, which mostly preserves the on-axis signals from tissue but reduces acoustic clutter contributions when multiplied with the beamformed radio-frequency (RF) signals. In this paper, in vivo performance of the MPAX technique was evaluated in abdominal ultrasound using data sets obtained from 10 human subjects referred for abdominal ultrasound at the USC Keck School of Medicine. Improvement in image contrast was quantified, first, by the contrast-to-noise ratio (CNR) and, second, by the rating of two experienced radiologists. The MPAX technique was evaluated for longitudinal and transverse views of the abdominal aorta, the inferior vena cava, the gallbladder, and the portal vein. Our in vivo results and analyses demonstrate the feasibility of the MPAX technique in enhancing image contrast in abdominal ultrasound and show potential for creating high contrast ultrasound images with improved target detectability and diagnostic confidence.

An Aerodynamic Performance Evaluation of the NASA/Ames Research Center Advanced Concepts Flight Simulator. M.S. Thesis

NASA Technical Reports Server (NTRS)

Donohue, Paul F.

1987-01-01

The results of an aerodynamic performance evaluation of the National Aeronautics and Space Administration (NASA)/Ames Research Center Advanced Concepts Flight Simulator (ACFS), conducted in association with the Navy-NASA Joint Institute of Aeronautics, are presented. The ACFS is a full-mission flight simulator which provides an excellent platform for the critical evaluation of emerging flight systems and aircrew performance. The propulsion and flight dynamics models were evaluated using classical flight test techniques. The aerodynamic performance model of the ACFS was found to realistically represent that of current day, medium range transport aircraft. Recommendations are provided to enhance the capabilities of the ACFS to a level forecast for 1995 transport aircraft. The graphical and tabular results of this study will establish a performance section of the ACFS Operation's Manual.

Pulmonary embolism in pediatric patients survey of CT pulmonary angiography practices and policies.

PubMed

Lee, Edward Y; Zurakowski, David; Boiselle, Phillip M

2010-12-01

To determine the current policies and practices of Society for Pediatric Radiology (SPR) members regarding the evaluation of pediatric patients with suspected pulmonary embolism (PE) with an emphasis on use of computed tomography pulmonary angiography (CTPA). Institutional review board exemption was granted for this study. Surveys were mailed electronically to the 1575 members of the SPR representing 416 institutions. Information gathered included the existence of written policies, the imaging study of choice for suspected PE, routine acquisition of chest radiographs before CTPA, currently used CTPA techniques, modifications of protocols for radiation dose reduction, typical DLP (dose-length-product) for CTPA, and estimated annual frequency of performing CTPA for evaluating PE in children. Survey items pertaining to policies and practices were compared between practice settings and populations using chi-square analysis. One hundred and sixty members representing 118 institutions responded, which resulted in a response rate of 28% (118/416), on an institutional basis. Of these 118 respondents, 104 (88%) perform CTPA in children with clinical suspicion of PE. Of the 104 respondents who perform CTPA, 26 (25%) have a written policy for CTPA, 93 (89%) perform CTPA as the first study choice, and 67 (64%) routinely obtain chest radiographs before CTPA. The most commonly used CTPA techniques in children with clinical suspicion of PE include intravenous contrast amount of 2 mL/kg, mechanical injection of intravenous contrast, and tailored bolus tracking method for CTPA scan initiation by observing the Hounsfield units of contrast in the central pulmonary artery on the monitoring scan. Sixty respondents (58%) modify CTPA imaging protocols for evaluating PE in children in order to decrease radiation dose. The two most common modifications for radiation dose reduction were reduced mAs in 41 (68%) and automatic exposure control in 38 (63%). The majority of respondents (88%) did not know the typical DLP for a 20-kg child during CTPA study performed to evaluate for PE. A significantly greater percentage of radiation dose-reduction techniques are performed within academic institutions compared with private institutions (P = .03). Most survey respondents perform CTPA as the study of choice for evaluating PE in children, but there is considerable variability in their policies and practices. Respondents from academic medical centers are more likely to employ radiation dose-reduction techniques for CTPA than those in private practice settings. Copyright © 2010 AUR. Published by Elsevier Inc. All rights reserved.

Comparison of commercial analytical techniques for measuring chlorine dioxide in urban desalinated drinking water.

PubMed

Ammar, T A; Abid, K Y; El-Bindary, A A; El-Sonbati, A Z

2015-12-01

Most drinking water industries are closely examining options to maintain a certain level of disinfectant residual through the entire distribution system. Chlorine dioxide is one of the promising disinfectants that is usually used as a secondary disinfectant, whereas the selection of the proper monitoring analytical technique to ensure disinfection and regulatory compliance has been debated within the industry. This research endeavored to objectively compare the performance of commercially available analytical techniques used for chlorine dioxide measurements (namely, chronoamperometry, DPD (N,N-diethyl-p-phenylenediamine), Lissamine Green B (LGB WET) and amperometric titration), to determine the superior technique. The commonly available commercial analytical techniques were evaluated over a wide range of chlorine dioxide concentrations. In reference to pre-defined criteria, the superior analytical technique was determined. To discern the effectiveness of such superior technique, various factors, such as sample temperature, high ionic strength, and other interferences that might influence the performance were examined. Among the four techniques, chronoamperometry technique indicates a significant level of accuracy and precision. Furthermore, the various influencing factors studied did not diminish the technique's performance where it was fairly adequate in all matrices. This study is a step towards proper disinfection monitoring and it confidently assists engineers with chlorine dioxide disinfection system planning and management.

A New Data Representation Based on Training Data Characteristics to Extract Drug Name Entity in Medical Text

PubMed Central

Basaruddin, T.

2016-01-01

One essential task in information extraction from the medical corpus is drug name recognition. Compared with text sources come from other domains, the medical text mining poses more challenges, for example, more unstructured text, the fast growing of new terms addition, a wide range of name variation for the same drug, the lack of labeled dataset sources and external knowledge, and the multiple token representations for a single drug name. Although many approaches have been proposed to overwhelm the task, some problems remained with poor F-score performance (less than 0.75). This paper presents a new treatment in data representation techniques to overcome some of those challenges. We propose three data representation techniques based on the characteristics of word distribution and word similarities as a result of word embedding training. The first technique is evaluated with the standard NN model, that is, MLP. The second technique involves two deep network classifiers, that is, DBN and SAE. The third technique represents the sentence as a sequence that is evaluated with a recurrent NN model, that is, LSTM. In extracting the drug name entities, the third technique gives the best F-score performance compared to the state of the art, with its average F-score being 0.8645. PMID:27843447

Identification of active sources inside cavities using the equivalent source method-based free-field recovery technique

NASA Astrophysics Data System (ADS)

Bi, Chuan-Xing; Hu, Ding-Yu; Zhang, Yong-Bin; Jing, Wen-Qian

2015-06-01

In previous studies, an equivalent source method (ESM)-based technique for recovering the free sound field in a noisy environment has been successfully applied to exterior problems. In order to evaluate its performance when applied to a more general noisy environment, that technique is used to identify active sources inside cavities where the sound field is composed of the field radiated by active sources and that reflected by walls. A patch approach with two semi-closed surfaces covering the target active sources is presented to perform the measurements, and the field that would be radiated by these target active sources into free space is extracted from the mixed field by using the proposed technique, which will be further used as the input of nearfield acoustic holography for source identification. Simulation and experimental results validate the effectiveness of the proposed technique for source identification in cavities, and show the feasibility of performing the measurements with a double layer planar array.

Evaluation of a data fusion approach to estimate daily PM2.5 levels in North China

PubMed Central

Liang, Fengchao; Gao, Meng; Xiao, Qingyang; Carmichael, Gregory R.

2017-01-01

PM2.5 air pollution has been a growing concern worldwide. Previous studies have conducted several techniques to estimate PM2.5 exposure spatiotemporally in China, but all these have limitations. This study was to develop a data fusion approach and compare it with kriging and Chemistry Module. Two techniques were applied to create daily spatial cover of PM2.5 in grid cells with a resolution of 10 km in North China in 2013, respectively, which was kriging with an external drift (KED) and Weather Research and Forecast Model with Chemistry Module (WRF-Chem). A data fusion technique was developed by fusing PM2.5 concentration predicted by KED and WRF-Chem, accounting for the distance from the central of grid cell to the nearest ground observations and daily spatial correlations between WRF-Chem and observations. Model performances were evaluated by comparing them with ground observations and the spatial prediction errors. KED and data fusion performed better at monitoring sites with a daily model R2 of 0.95 and 0.94, respectively and PM2.5 was overestimated by WRF-Chem (R2=0.51). KED and data fusion performed better around the ground monitors, WRF-Chem performed relative worse with high prediction errors in the central of study domain. In our study, both KED and data fusion technique provided highly accurate PM2.5. Current monitoring network in North China was dense enough to provide a reliable PM2.5 prediction by interpolation technique. PMID:28599195

Evaluation of a data fusion approach to estimate daily PM2.5 levels in North China.

PubMed

Liang, Fengchao; Gao, Meng; Xiao, Qingyang; Carmichael, Gregory R; Pan, Xiaochuan; Liu, Yang

2017-10-01

PM 2.5 air pollution has been a growing concern worldwide. Previous studies have conducted several techniques to estimate PM 2.5 exposure spatiotemporally in China, but all these have limitations. This study was to develop a data fusion approach and compare it with kriging and Chemistry Module. Two techniques were applied to create daily spatial cover of PM 2.5 in grid cells with a resolution of 10km in North China in 2013, respectively, which was kriging with an external drift (KED) and Weather Research and Forecast Model with Chemistry Module (WRF-Chem). A data fusion technique was developed by fusing PM 2.5 concentration predicted by KED and WRF-Chem, accounting for the distance from the central of grid cell to the nearest ground observations and daily spatial correlations between WRF-Chem and observations. Model performances were evaluated by comparing them with ground observations and the spatial prediction errors. KED and data fusion performed better at monitoring sites with a daily model R 2 of 0.95 and 0.94, respectively and PM 2.5 was overestimated by WRF-Chem (R 2 =0.51). KED and data fusion performed better around the ground monitors, WRF-Chem performed relative worse with high prediction errors in the central of study domain. In our study, both KED and data fusion technique provided highly accurate PM 2.5 . Current monitoring network in North China was dense enough to provide a reliable PM 2.5 prediction by interpolation technique. Copyright © 2017. Published by Elsevier Inc.

Outcomes of mechanical stapling for postlaryngectomy open pharyngotomy closure.

PubMed

Paddle, Paul; Husain, Inna; McHugh, Lauren; Franco, Ramon

2017-03-01

A total laryngectomy (TL) is performed as a primary or salvage therapy for laryngeal carcinoma. Pharyngotomy closure after TL is typically performed using manual sutures. Automatic stapling devices are routinely used in thoracoabdominal surgery, but have not been widely accepted for use in pharyngotomy closure. Previously described closed stapling techniques of pharyngeal closure do not allow direct evaluation of surgical margins and are limited to endolaryngeal disease. We describe an open technique for pharyngotomy closure using a mechanical stapling device. Retrospective review. A review was conducted of 16 total laryngectomies performed from May 2008 to August 2015 utilizing an Ethicon Endopath ETS Compact-Flex 45 stapler. Sixteen patients (15 male, one female), mean age 69 years, received open TL (14 salvage, two primary) with endostapler pharyngeal closure and primary tracheoesophageal puncture (TEP). Surgical time averaged 218 minutes. Median time to swallowing was 4 days (range, 2-240 days) and mean hospital stay 6 days (range, 3-10 days). Fistula incidence was 31% (5/16) overall and 36% (5/14) in the postradiation patients. Mechanical stapling is a simple method for postlaryngectomy open pharyngotomy closure. This technique allows evaluation of margins, easy primary TEP, and the opportunity for early swallowing and shorter hospital stays. In addition, it can be performed for closure of salvage laryngectomies with rates of fistula formation similar to that found in the literature using suture closure techniques. Future studies are necessary to compare oncological results and surgical complications between the open and closed stapling techniques and to traditional suture closure. 4 Laryngoscope, 127:605-610, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

LOFT Debriefings: An Analysis of Instructor Techniques and Crew Participation

NASA Technical Reports Server (NTRS)

Dismukes, R. Key; Jobe, Kimberly K.; McDonnell, Lori K.

1997-01-01

This study analyzes techniques instructors use to facilitate crew analysis and evaluation of their Line-Oriented Flight Training (LOFT) performance. A rating instrument called the Debriefing Assessment Battery (DAB) was developed which enables raters to reliably assess instructor facilitation techniques and characterize crew participation. Thirty-six debriefing sessions conducted at five U.S. airlines were analyzed to determine the nature of instructor facilitation and crew participation. Ratings obtained using the DAB corresponded closely with descriptive measures of instructor and crew performance. The data provide empirical evidence that facilitation can be an effective tool for increasing the depth of crew participation and self-analysis of CRM performance. Instructor facilitation skill varied dramatically, suggesting a need for more concrete hands-on training in facilitation techniques. Crews were responsive but fell short of actively leading their own debriefings. Ways to improve debriefing effectiveness are suggested.

Locality-Aware CTA Clustering For Modern GPUs

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

Li, Ang; Song, Shuaiwen; Liu, Weifeng

2017-04-08

In this paper, we proposed a novel clustering technique for tapping into the performance potential of a largely ignored type of locality: inter-CTA locality. We first demonstrated the capability of the existing GPU hardware to exploit such locality, both spatially and temporally, on L1 or L1/Tex unified cache. To verify the potential of this locality, we quantified its existence in a broad spectrum of applications and discussed its sources of origin. Based on these insights, we proposed the concept of CTA-Clustering and its associated software techniques. Finally, We evaluated these techniques on all modern generations of NVIDIA GPU architectures. Themore » experimental results showed that our proposed clustering techniques could significantly improve on-chip cache performance.« less

Technique of laparoscopic posterior truncal vagotomy and anterior seromyotomy using endoscopic esophogeal transillumination

NASA Astrophysics Data System (ADS)

Reed, David M.; Tortella, Bartholomew J.; Dolan, William V.; Pennino, Ralph P.; Treat, Michael R.

1993-05-01

The unprecedented rapid and successful adoption of laparoscopic cholecystectomy has prompted the evaluation of converting other standard open surgical procedures to a laparoscopic technique. A wide variety of laparoscopic acid reduction procedures have been successfully accomplished by groups in this country and abroad. Our group reviewed the literature on the many types of open peptic ulcer operations, as well as the ones performed laparoscopically. We elected to perfect the technique of posterior truncal vagotomy and anterior seromyotomy (PTVAS). After extensive animal laboratory work, we performed PTVAS on four patients with documented recurrent peptic ulcer disease. We describe our technique as it evolved and in particular note the usefulness of endoscopic esophageal transillumination. In addition, we report our results and discuss their implications.

Performance evaluation of Arizona's LTPP SPS-6 project : strategic study of rehabilitation techniques.

DOT National Transportation Integrated Search

2013-10-01

As part of the Long Term Pavement Performance (LTPP) Program, the Arizona Department of Transportation (ADOT) : constructed 19 Specific Pavement Studies 6 (SPS6) test sections on Interstate 40 near Flagstaff. The SPS6 project : studied the effe...

Screening fungicides for use in fish culture: Evaluation of the agar plug transfer, cellophane transfer, and agar dilution methods

USGS Publications Warehouse

Bailey, Tom A.

1983-01-01

The reliability, reproducibility, and usefulness of three screening methods -- the cellophane transfer, the agar plug transfer, and the agar dilution -- to screen aquatic fungicides were evaluated. Achlya flagellata and Saprolegnia hypogyna were exposed to 1, 10, and 100 mg/L of malachite green to test each method. The cellophane transfer and agar plug transfer techniques had similar reliability and reproducibility in rating fungicidal activity, and were both superior to the agar dilution technique. The agar plug transfer and agar dilution techniques adequately projected in vivo activity of malachite green, but the cellophane transfer technique overestimated its activity. Overall, the agar plug transfer technique most accurately rated the activity of malachite green and was the easiest test to perform. It therefore appears to be the method of choice for testing aquatic fungicides.

A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study

PubMed Central

Mokhtari, Negar; Shirazi, Alireza-Sarraf

2017-01-01

Background Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. Material and Methods In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests (P<0.05). Results There were no significant differences between electronic apex locator Root ZXII and conventional method in accuracy of root canal length determination. However significantly less time was needed for instrumenting with rotary files (P=0.000). Conclusions Considering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth. Key words:Rotary technique, conventional technique, pulpectomy, primary teeth. PMID:29302280

A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study.

PubMed

Mokhtari, Negar; Shirazi, Alireza-Sarraf; Ebrahimi, Masoumeh

2017-11-01

Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests ( P <0.05). There were no significant differences between electronic apex locator Root ZXII and conventional method in accuracy of root canal length determination. However significantly less time was needed for instrumenting with rotary files ( P =0.000). Considering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth. Key words: Rotary technique, conventional technique, pulpectomy, primary teeth.

A case study on Measurement of Degree of Performance of an Industry by using Lean Score Technique

NASA Astrophysics Data System (ADS)

Srinivasa Rao, P.; Niraj, Malay

2016-09-01

Lean manufacturing concept is becoming a very important strategy for both academicians and practitioners in the recent times, and Japanese are using this practice for more than a decade. In this present scenario, this paper describes an innovative approach for lean performance evaluation by using fuzzy membership functions before and after implementing lean manufacturing techniques and formulating a model to establish the lean score through the lean attributes by eliminating major losses. It shows a systematic lean performance measurement by producing a final integrated unit less-score.

Standardization of dynamic contrast-enhanced ultrasound for the evaluation of antiangiogenic therapies: the French multicenter Support for Innovative and Expensive Techniques Study.

PubMed

Lassau, Nathalie; Chapotot, Louis; Benatsou, Baya; Vilgrain, Valérie; Kind, Michèle; Lacroix, Joëlle; Cuinet, Marie; Taieb, Sophie; Aziza, Richard; Sarran, Antony; Labbe, Catherine; Gallix, Benoît; Lucidarme, Olivier; Ptak, Yvette; Rocher, Laurence; Caquot, Louis Michel; Chagnon, Sophie; Marion, Denis; Luciani, Alain; Uzan-Augui, Joëlle; Koscielny, Serge

2012-12-01

The objectives of this study are to describe the standardization and dissemination of dynamic contrast-enhanced ultrasound (DCE-US) for the evaluation of antiangiogenic treatments in solid tumors across 19 oncology centers in France and to define a quality score to account for the variability of the evaluation criteria used to collect DCE-US data. This prospective Soutien aux Techniques Innovantes Coûteuses (Support for Innovative and Expensive Techniques) DCE-US study included patients with metastatic breast cancer, melanoma, colon cancer, gastrointestinal stromal tumors, renal cell carcinoma and patients with primary hepatocellular carcinoma tumors treated with antiangiogenic therapy. The DCE-US method was made available across 19 oncology centers in France. Overall, 2339 DCE-US examinations were performed by 65 radiologists in 539 patients.One target site per patient was studied. Standardized DCE-US examinations were performed before treatment (day 0) and at days 7, 15, 30, and 60. Dynamic contrast-enhanced ultrasound data were transferred from the different sites to the main study center at the Institut Gustave-Roussy for analysis. Quantitative analyses were performed with a mathematical model to determine 7 DCE-US functional parameters using raw linear data. Radiologists had to evaluate 6 criteria that were potentially linked to the precision of the evaluation of these parameters: lesion size, target motion, loss of target, clear borders, total acquisition of wash-in, and vascular recognition imaging window adapted to the lesion size.Eighteen DCE-US examinations were randomly selected from the Soutien aux Techniques Innovantes Coûteuses (Support for Innovative and Expensive Techniques) database. Each examination was quantified twice by 8 engineers/radiologists trained to evaluate the perfusion parameters. The intraobserver variability was estimated on the basis of differences between examinations performed by the same radiologist. The mean coefficient of variability associated with each quality criterion was estimated. The final quality score, ranging from 0 to 5, was defined according to the value of coefficient of variability for each criterion. A total of 2062 examinations were stored with raw linear data. Five criteria were found to have a major impact on quality: lesion size, motion, loss of target, borders, and total acquisition of wash-in. Only 3% of the examinations were of poor quality (quality of 0); quality was correlated with the radiologists' experience, such that it was significantly higher for radiologists who had performed more than 60 DCE-US examinations (P < 0.0001). The DCE-US methodology has been successfully provided to several centers across France together with strict rules for quality assessment. Only 3% of examinations carried out at these centers were considered not interpretable.

Automated Quantification of Pneumothorax in CT

PubMed Central

Do, Synho; Salvaggio, Kristen; Gupta, Supriya; Kalra, Mannudeep; Ali, Nabeel U.; Pien, Homer

2012-01-01

An automated, computer-aided diagnosis (CAD) algorithm for the quantification of pneumothoraces from Multidetector Computed Tomography (MDCT) images has been developed. Algorithm performance was evaluated through comparison to manual segmentation by expert radiologists. A combination of two-dimensional and three-dimensional processing techniques was incorporated to reduce required processing time by two-thirds (as compared to similar techniques). Volumetric measurements on relative pneumothorax size were obtained and the overall performance of the automated method shows an average error of just below 1%. PMID:23082091

Decision-directed detector for overlapping PCM/NRZ signals.

NASA Technical Reports Server (NTRS)

Wang, C. D.; Noack, T. L.

1973-01-01

A decision-directed (DD) technique for the detection of overlapping PCM/NRZ signals in the presence of white Gaussian noise is investigated. The performance of the DD detector is represented by probability of error Pe versus input signal-to-noise ratio (SNR). To examine how much improvement in performance can be achieved with this technique, Pe's with and without DD feedback are evaluated in parallel. Further, analytical results are compared with those found by Monte Carlo simulations. The results are in good agreement.

Conductor gestures influence evaluations of ensemble performance

PubMed Central

Morrison, Steven J.; Price, Harry E.; Smedley, Eric M.; Meals, Cory D.

2014-01-01

Previous research has found that listener evaluations of ensemble performances vary depending on the expressivity of the conductor’s gestures, even when performances are otherwise identical. It was the purpose of the present study to test whether this effect of visual information was evident in the evaluation of specific aspects of ensemble performance: articulation and dynamics. We constructed a set of 32 music performances that combined auditory and visual information and were designed to feature a high degree of contrast along one of two target characteristics: articulation and dynamics. We paired each of four music excerpts recorded by a chamber ensemble in both a high- and low-contrast condition with video of four conductors demonstrating high- and low-contrast gesture specifically appropriate to either articulation or dynamics. Using one of two equivalent test forms, college music majors and non-majors (N = 285) viewed sixteen 30 s performances and evaluated the quality of the ensemble’s articulation, dynamics, technique, and tempo along with overall expressivity. Results showed significantly higher evaluations for performances featuring high rather than low conducting expressivity regardless of the ensemble’s performance quality. Evaluations for both articulation and dynamics were strongly and positively correlated with evaluations of overall ensemble expressivity. PMID:25104944

Using Job Analysis Techniques to Understand Training Needs for Promotores de Salud.

PubMed

Ospina, Javier H; Langford, Toshiko A; Henry, Kimberly L; Nelson, Tristan Q

2018-04-01

Despite the value of community health worker programs, such as Promotores de Salud, for addressing health disparities in the Latino community, little consensus has been reached to formally define the unique roles and duties associated with the job, thereby creating unique job training challenges. Understanding the job tasks and worker attributes central to this work is a critical first step for developing the training and evaluation systems of promotores programs. Here, we present the process and findings of a job analysis conducted for promotores working for Planned Parenthood. We employed a systematic approach, the combination job analysis method, to define the job in terms of its work and worker requirements, identifying key job tasks, as well as the worker attributes necessary to effectively perform them. Our results suggest that the promotores' job encompasses a broad range of activities and requires an equally broad range of personal characteristics to perform. These results played an important role in the development of our training and evaluation protocols. In this article, we introduce the technique of job analysis, provide an overview of the results from our own application of this technique, and discuss how these findings can be used to inform a training and performance evaluation system. This article provides a template for other organizations implementing similar community health worker programs and illustrates the value of conducting a job analysis for clarifying job roles, developing and evaluating job training materials, and selecting qualified job candidates.

The Use of Techniques of Sensory Evaluation as a Framework for Teaching Experimental Methods.

ERIC Educational Resources Information Center

Bennett, R.; Hamilton, M.

1981-01-01

Describes sensory assessment techniques and conditions for their satisfactory performance, including how they can provide open-ended exercises and advantages as relatively inexpensive and simple methods of teaching experimentation. Experiments described focus on diffusion of salt into potatoes after being cooked in boiled salted water. (Author/JN)

[Clinical and radiographic evaluation of a new percutaneous technique for moderate to severe hallux valgus deformity].

PubMed

Vélez-de Lachica, J C; Valdez-Jiménez, L A; Inzunza-Sánchez, J M

2017-01-01

Hallux valgus is considered the most common musculoskeletal deformity, with a prevalence of 88%. There are more than 130 surgical techniques for its treatment; currently, percutaneous ones are popular; however, they do not take into account the metatarsal-phalangeal correction angle. The aim of this study is to propose a modified technique for the correction of the percutaneous metatarsal-phalangeal and inter-metatarsal angles and to evaluate its clinical and radiological results. An experimental, prospective and longitudinal study in 10 patients with moderate to severe hallux valgus according to the classification of Coughlin and Mann were collected; the results were evaluated with the AOFAS scale at 15, 30, 60 and 90 days. The McBride technique and the technique of percutaneous anchor with the proposed amendment were performed. The AOFAS scale was applied as described, finding a progressive increase of the rating; the average correction of the inter-metatarsal angle was 8.8 degrees and of the metatarsal-phalangeal, 9.12. The modified technique of percutaneous anchor showed clear clinical and radiographic improvements in the short term. Our modified technique is proposed for future projects, including a large sample with long-term follow-up.

Meta-analysis of the technical performance of an imaging procedure: guidelines and statistical methodology.

PubMed

Huang, Erich P; Wang, Xiao-Feng; Choudhury, Kingshuk Roy; McShane, Lisa M; Gönen, Mithat; Ye, Jingjing; Buckler, Andrew J; Kinahan, Paul E; Reeves, Anthony P; Jackson, Edward F; Guimaraes, Alexander R; Zahlmann, Gudrun

2015-02-01

Medical imaging serves many roles in patient care and the drug approval process, including assessing treatment response and guiding treatment decisions. These roles often involve a quantitative imaging biomarker, an objectively measured characteristic of the underlying anatomic structure or biochemical process derived from medical images. Before a quantitative imaging biomarker is accepted for use in such roles, the imaging procedure to acquire it must undergo evaluation of its technical performance, which entails assessment of performance metrics such as repeatability and reproducibility of the quantitative imaging biomarker. Ideally, this evaluation will involve quantitative summaries of results from multiple studies to overcome limitations due to the typically small sample sizes of technical performance studies and/or to include a broader range of clinical settings and patient populations. This paper is a review of meta-analysis procedures for such an evaluation, including identification of suitable studies, statistical methodology to evaluate and summarize the performance metrics, and complete and transparent reporting of the results. This review addresses challenges typical of meta-analyses of technical performance, particularly small study sizes, which often causes violations of assumptions underlying standard meta-analysis techniques. Alternative approaches to address these difficulties are also presented; simulation studies indicate that they outperform standard techniques when some studies are small. The meta-analysis procedures presented are also applied to actual [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) test-retest repeatability data for illustrative purposes. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Meta-analysis of the technical performance of an imaging procedure: Guidelines and statistical methodology

PubMed Central

Huang, Erich P; Wang, Xiao-Feng; Choudhury, Kingshuk Roy; McShane, Lisa M; Gönen, Mithat; Ye, Jingjing; Buckler, Andrew J; Kinahan, Paul E; Reeves, Anthony P; Jackson, Edward F; Guimaraes, Alexander R; Zahlmann, Gudrun

2017-01-01

Medical imaging serves many roles in patient care and the drug approval process, including assessing treatment response and guiding treatment decisions. These roles often involve a quantitative imaging biomarker, an objectively measured characteristic of the underlying anatomic structure or biochemical process derived from medical images. Before a quantitative imaging biomarker is accepted for use in such roles, the imaging procedure to acquire it must undergo evaluation of its technical performance, which entails assessment of performance metrics such as repeatability and reproducibility of the quantitative imaging biomarker. Ideally, this evaluation will involve quantitative summaries of results from multiple studies to overcome limitations due to the typically small sample sizes of technical performance studies and/or to include a broader range of clinical settings and patient populations. This paper is a review of meta-analysis procedures for such an evaluation, including identification of suitable studies, statistical methodology to evaluate and summarize the performance metrics, and complete and transparent reporting of the results. This review addresses challenges typical of meta-analyses of technical performance, particularly small study sizes, which often causes violations of assumptions underlying standard meta-analysis techniques. Alternative approaches to address these difficulties are also presented; simulation studies indicate that they outperform standard techniques when some studies are small. The meta-analysis procedures presented are also applied to actual [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) test–retest repeatability data for illustrative purposes. PMID:24872353

Seeing the System through the End Users' Eyes: Shadow Expert Technique for Evaluating the Consistency of a Learning Management System

NASA Astrophysics Data System (ADS)

Holzinger, Andreas; Stickel, Christian; Fassold, Markus; Ebner, Martin

Interface consistency is an important basic concept in web design and has an effect on performance and satisfaction of end users. Consistency also has significant effects on the learning performance of both expert and novice end users. Consequently, the evaluation of consistency within a e-learning system and the ensuing eradication of irritating discrepancies in the user interface redesign is a big issue. In this paper, we report of our experiences with the Shadow Expert Technique (SET) during the evaluation of the consistency of the user interface of a large university learning management system. The main objective of this new usability evaluation method is to understand the interaction processes of end users with a specific system interface. Two teams of usability experts worked independently from each other in order to maximize the objectivity of the results. The outcome of this SET method is a list of recommended changes to improve the user interaction processes, hence to facilitate high consistency.

Evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia.

PubMed

Yimer, Mulat; Hailu, Tadesse; Mulu, Wondemagegn; Abera, Bayeh

2015-12-26

Although the sensitivity of Wet mount technique is questionable, it is the major diagnostic technique for routine diagnosis of intestinal parasitosis in Ethiopia. Therefore, the aim of this study was the evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia. A cross sectional study was conducted from May to June 2013. Single stool sample was processed for direct, Formol ether concentration (FEC) and Kato Katz methods. The sensitivity and negative predictive value (NPV) of diagnostic tests were calculated in terms of the "Gold" standard method (the combined result of the three methods altogether). A total of 422 school age children were participated in this study. The prevalence of intestinal parasites was high (74.6%) with Kato Katz technique. The sensitivity of Wet mount, FEC and Kato Katz tests against the Gold standard test was 48.9, 63.1 and 93.7%, respectively. Kato Katz technique revealed a better NPV 80.4 (80.1-80.6) as compared to the Wet mount (33.7%) and FEC techniques (41.3%). In this study, the Kato Katz technique outperformed the other two methods but the true values for sensitivity, specificity and diagnostic values are not known. Moreover, it is labor intensive and not easily accessible. Hence, it is preferable to use FEC technique to complement the Wet mount test.

Transverse mucoperiosteal flap inset by rotation for cleft palate repair: technique and outcomes.

PubMed

Black, Jonathan S; Gampper, Thomas J

2014-01-01

Cleft palate is a relatively common deformity with various techniques described for its repair. Most techniques address the hard palate portion of the cleft with bilateral mucoperiosteal flaps transposed to the midline. This results in superimposed, linear closure layers directly over the cleft and may predispose the repair to oronasal fistula formation. This report details an alternative technique of flap rotation with an outcome analysis. A retrospective chart analysis was performed of all patients having undergone primary palatoplasty for cleft palate. Demographics and cleft Veau type were recorded. Postoperative speech outcomes were assessed by standardized speech evaluation performed by 2 speech language pathologists. The presence and location of oronasal fistulae was assessed and recorded by the surgeon and speech language pathologists in follow-up evaluations. The study revealed an overall incidence of velopharyngeal insufficiency of 5.7% using this surgical technique. It also revealed a fistula rate of 8.6%. Secondary surgery has been successful in those patients in which it was indicated. Eleven (31%) patients were diagnosed with Robin sequence. This technique demonstrates excellent early outcomes in a difficult subset of cleft patients including a high proportion of those with Pierre Robin sequence. The technique addresses the inherent disadvantages to a linear closure over the bony cleft. The variability in its design provides the surgeon another option for correction of this deformity.

Time-Sharing-Based Synchronization and Performance Evaluation of Color-Independent Visual-MIMO Communication.

PubMed

Kwon, Tae-Ho; Kim, Jai-Eun; Kim, Ki-Doo

2018-05-14

In the field of communication, synchronization is always an important issue. The communication between a light-emitting diode (LED) array (LEA) and a camera is known as visual multiple-input multiple-output (MIMO), for which the data transmitter and receiver must be synchronized for seamless communication. In visual-MIMO, LEDs generally have a faster data rate than the camera. Hence, we propose an effective time-sharing-based synchronization technique with its color-independent characteristics providing the key to overcome this synchronization problem in visual-MIMO communication. We also evaluated the performance of our synchronization technique by varying the distance between the LEA and camera. A graphical analysis is also presented to compare the symbol error rate (SER) at different distances.

Does increased electrocautery during adenoidectomy lead to neck pain?

PubMed

Henry, Lakeisha R; Gal, Thomas J; Mair, Eric A

2005-10-01

The objective was to assess the impact of electrocautery on complications in adenoidectomy. We sought to quantify cautery-related temperature changes in prevertebral fascia that may occur during the procedure, retrospectively evaluate the incidence of cautery-related complications, and prospectively assess the role of cautery in postoperative neck pain. Three consecutive related trials were performed. Initially, adenoidectomy was performed on 20 fresh cadavers, using a thermister to evaluate temperature changes in the prevertebral fascia after electrocautery (30 watts over a 30-second period). Next, retrospective analysis of adenoidectomy complications in 1206 children over a 5-year period was performed. Based on these findings, a prospective study of the incidence of neck pain following adenoidectomy was performed in a cohort of 276 children. Adenoidectomy technique, wattage, and duration of electrocautery were recorded for each child. Children with significant neck pain were evaluated with MRI. Peak thermister readings averaged 74 degrees C, for a mean change of 51.8 degrees C. Complications observed in retrospective analysis included neck pain (3), Grisel's syndrome (1), prolonged velopharyngeal insufficiency (1), retropharyngeal edema (1), and severe nasopharyngeal stenosis (1). The incidence of neck pain in the prospective study was 12% (33 pts), and was independent of adenoidectomy technique, cautery wattage, or duration of cautery use. MRIs revealed edema without abscess. Cautery can result in substantial temperature changes in the surgical adenoid bed. Despite this, the incidence of complications, specifically neck pain, associated with adenoidectomy is low, although underreported. Complications appear to be independent of adenoidectomy technique and cautery use.

Human Factors Society, Annual Meeting, 35th, San Francisco, CA, Sept. 2-6, 1991, Proceedings. Vols. 1 2

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

Not Available

These proceedings discuss human factor issues related to aerospace systems, aging, communications, computer systems, consumer products, education and forensic topics, environmental design, industrial ergonomics, international technology transfer, organizational design and management, personality and individual differences in human performance, safety, system development, test and evaluation, training, and visual performance. Particular attention is given to HUDs, attitude indicators, and sensor displays; human factors of space exploration; behavior and aging; the design and evaluation of phone-based interfaces; knowledge acquisition and expert systems; handwriting, speech, and other input techniques; interface design for text, numerics, and speech; and human factor issues in medicine. Also discussedmore » are cumulative trauma disorders, industrial safety, evaluative techniques for automation impacts on the human operators, visual issues in training, and interpreting and organizing human factor concepts and information.« less

Promoting response variability and stimulus generalization in martial arts training.

PubMed Central

Harding, Jay W; Wacker, David P; Berg, Wendy K; Rick, Gary; Lee, John F

2004-01-01

The effects of reinforcement and extinction on response variability and stimulus generalization in the punching and kicking techniques of 2 martial arts students were evaluated across drill and sparring conditions. During both conditions, the students were asked to demonstrate different techniques in response to an instructor's punching attack. During baseline, the students received no feedback on their responses in either condition. During the intervention phase, the students received differential reinforcement in the form of instructor feedback for each different punching or kicking technique they performed during a session of the drill condition, but no reinforcement was provided for techniques in the sparring condition. Results showed that both students increased the number of different techniques they performed when reinforcement and extinction procedures were conducted during the drill condition, and that this increase in response variability generalized to the sparring condition. PMID:15293637

Sclerotherapy of the pampiniform plexus with modified Marmar technique in children and adolescents.

PubMed

Carmignani, Luca; Casellato, Stefano; Galasso, Giacomo; Bozzini, Giorgio; Spinelli, Matteo; Dell'Agnola, Carlo Alberto; Rocco, Francesco

2009-01-01

Treatment of varicocele in children is a debated problem for which no validated guidelines exist. Several techniques have been proposed to solve this problem. The aim of this study was to evaluate the effectiveness and applicability of a modified Marmar technique in the treatment of varicocele in children and adolescents. From April 2004 to September 2005, we evaluated 25 patients between the ages of 9 and 18 (mean 14.4) years, who suffered from left-sided varicocele with concomitant testicular hypotrophy. The diagnosis was ascertained clinically and with scrotal color Doppler ultrasound using the Dubin and Amelar classification. In 2 cases phimosis was also present. The operation was performed according to a modified Marmar technique, using embolization of the pampiniform plexus with 2 ml of 3% polidocanol. Patients underwent clinical evaluation and scrotal color Doppler ultrasound at 1 week and 3 and 6 months. The mean duration of the operation was 42 min. At 1 week after surgery no persistence of varicocele was found. In 1 patient, edema of the spermatic cord occurred for about 2 months with spontaneous regression, in 1 patient homolateral hydrocele was observed. At 6 months no other complications were reported. No case of testicular atrophy was observed. The technique described has already been validated in the adult population, and although we present only a small number of cases, the operation proved easy to perform, safe, of low cost and can be considered a valid alternative to the microsurgical technique in children and adolescents. Copyright 2009 S. Karger AG, Basel.

Performance evaluation of setback buildings with open ground storey on plain and sloping ground under earthquake loadings and mitigation of failure

NASA Astrophysics Data System (ADS)

Ghosh, Rahul; Debbarma, Rama

2017-06-01

Setback structures are highly vulnerable during earthquakes due to its vertical geometrical and mass irregularity, but the vulnerability becomes higher if the structures also have stiffness irregularity in elevation. The risk factor of such structure may increase, if the structure rests on sloping ground. In this paper, an attempt has been made to evaluate the seismic performance of setback structures resting on plain ground as well as in the slope of a hill, with soft storey configuration. The analysis has been performed in three individual methods, equivalent static force method, response spectrum method and time history method and extreme responses have been recorded for open ground storeyed setback building. To mitigate this soft storey effect and the extreme responses, three individual mitigation techniques have been adopted and the best solution among these three techniques is presented.

[Training of resident physicians in the recognition and treatment of an anaphylaxis case in pediatrics with simulation models].

PubMed

Enríquez, Diego; Lamborizio, María J; Firenze, Lorena; Jaureguizar, María de la P; Díaz Pumará, Estanislao; Szyld, Edgardo

2017-08-01

To evaluate the performance of resident physicians in diagnosing and treating a case of anaphylaxis, six months after participating in simulation training exercises. Initially, a group of pediatric residents were trained using simulation techniques in the management of critical pediatric cases. Based on their performance in this exercise, participants were assigned to one of 3 groups. At six months post-training, 4 residents were randomly chosen from each group to be re-tested, using the same performance measure as previously used. During the initial training session, 56 of 72 participants (78%) correctly identified and treated the case. Six months after the initial training, all 12 (100%) resident physicians who were re-tested successfully diagnosed and treated the simulated anaphylaxis case. The training through simulation techniques allowed correction or optimization of the treatment of simulated anaphylaxis cases in resident physicians evaluated after 6 months of the initial training.

Development and Evaluation of a Performance Modeling Flight Test Approach Based on Quasi Steady-State Maneuvers

NASA Technical Reports Server (NTRS)

Yechout, T. R.; Braman, K. B.

1984-01-01

The development, implementation and flight test evaluation of a performance modeling technique which required a limited amount of quasisteady state flight test data to predict the overall one g performance characteristics of an aircraft. The concept definition phase of the program include development of: (1) the relationship for defining aerodynamic characteristics from quasi steady state maneuvers; (2) a simplified in flight thrust and airflow prediction technique; (3) a flight test maneuvering sequence which efficiently provided definition of baseline aerodynamic and engine characteristics including power effects on lift and drag; and (4) the algorithms necessary for cruise and flight trajectory predictions. Implementation of the concept include design of the overall flight test data flow, definition of instrumentation system and ground test requirements, development and verification of all applicable software and consolidation of the overall requirements in a flight test plan.

Portal-endocrine and gastric-exocrine drainage technique of pancreas transplantation provides an easy access for evaluation of pancreatic allograft dysfunction: six-year experience at a single center.

PubMed

Zibari, Gazi B; Fallahzadeh, Mohammad Kazem; Hamidian Jahromi, Alireza; Zakhary, Joseph; Dies, David; Wellman, Greg; Singh, Neeraj; Shokouh-Amiri, Hosein

2014-01-01

The aim of this study is to report our six-year experience with portal-endocrine and gastric-exocrine drainage technique of pancreatic transplantation, which was first developed and implemented at our center in 2007. In this study, the outcomes of all patients at our center who had pancreas transplantation with portal-endocrine and gastric-exocrine drainage technique were evaluated. From October 2007 to November 2013, 38 patients had pancreas transplantation with this technique - 31 simultaneous kidney pancreas and seven pancreas alone. Median duration of follow-up was 3.8 years. One-, three-, and five-year patient and graft survival rates were 94%, 87%, 70% and 83%, 65%, 49%, respectively. For pancreas allograft dysfunction evaluation, 51 upper endoscopies were performed in 14 patients; donor duodenal biopsies were successfully obtained in 45 (88%). We detected nine episodes of acute rejection (eight patients) and seven episodes of cytomegalovirus (CMV) duodenitis (six patients). No patient developed any complication due to upper endoscopy. Portal-endocrine and gastric-exocrine drainage technique of pancreas transplantation provides lifelong easy access to the transplanted duodenum for evaluation of pancreatic allograft dysfunction.

Study of synthesis techniques for insensitive aircraft control systems

NASA Technical Reports Server (NTRS)

Harvey, C. A.; Pope, R. E.

1977-01-01

Insensitive flight control system design criteria was defined in terms of maximizing performance (handling qualities, RMS gust response, transient response, stability margins) over a defined parameter range. Wing load alleviation for the C-5A was chosen as a design problem. The C-5A model was a 79-state, two-control structure with uncertainties assumed to exist in dynamic pressure, structural damping and frequency, and the stability derivative, M sub w. Five new techniques (mismatch estimation, uncertainty weighting, finite dimensional inverse, maximum difficulty, dual Lyapunov) were developed. Six existing techniques (additive noise, minimax, multiplant, sensitivity vector augmentation, state dependent noise, residualization) and the mismatch estimation and uncertainty weighting techniques were synthesized and evaluated on the design example. Evaluation and comparison of these six techniques indicated that the minimax and the uncertainty weighting techniques were superior to the other six, and of these two, uncertainty weighting has lower computational requirements. Techniques based on the three remaining new concepts appear promising and are recommended for further research.

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 9. System and Subsystem Performance Models.

DOT National Transportation Integrated Search

1973-02-01

The volume presents the models used to analyze basic features of the system, establish feasibility of techniques, and evaluate system performance. The models use analytical expressions and computer simulations to represent the relationship between sy...

Computer program determines performance efficiency of remote measuring systems

NASA Technical Reports Server (NTRS)

Merewether, E. K.

1966-01-01

Computer programs control and evaluate instrumentation system performance for numerous rocket engine test facilities and prescribe calibration and maintenance techniques to maintain the systems within process specifications. Similar programs can be written for other test equipment in an industry such as the petrochemical industry.

Relation between ultrasonic properties, rheology and baking quality for bread doughs of widely differing formulation.

PubMed

Peressini, Donatella; Braunstein, Dobrila; Page, John H; Strybulevych, Anatoliy; Lagazio, Corrado; Scanlon, Martin G

2017-06-01

The objective was to evaluate whether an ultrasonic reflectance technique has predictive capacity for breadmaking performance of doughs made under a wide range of formulation conditions. Two flours of contrasting dough strength augmented with different levels of ingredients (inulin, oil, emulsifier or salt) were used to produce different bread doughs with a wide range of properties. Breadmaking performance was evaluated by conventional large-strain rheological tests on the dough and by assessment of loaf quality. The ultrasound tests were performed with a broadband reflectance technique in the frequency range of 0.3-6 MHz. Principal component analysis showed that ultrasonic attenuation and phase velocity at frequencies between 0.3 and 3 MHz are good predictors for rheological and bread scoring characteristics. Ultrasonic parameters had predictive capacity for breadmaking performance for a wide range of dough formulations. Lower frequency attenuation coefficients correlated well with conventional quality indices of both the dough and the bread. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Materials technology for Stirling space power converters

NASA Technical Reports Server (NTRS)

Baggenstoss, William; Mittendorf, Donald

1992-01-01

This program was conducted in support of the NASA LeRC development of the Stirling power converter (SPC) for space power applications. The objectives of this contract were: (1) to perform a technology review and analyses to support the evaluation of materials issues for the SPC; (2) to evaluate liquid metal compatibility issues of the SPC; (3) to evaluate and define a transient liquid phase diffusion bonding (TLPDB) process for the SPC joints to the Udimet 720 heater head; and (4) to evaluate alternative (to the TLPDB) joining techniques. In the technology review, several aspects of the current Stirling design were examined including the power converter assembly process, materials joining, gas bearings, and heat exchangers. The supporting analyses included GLIMPS power converter simulation in support of the materials studies, and system level analysis in support of the technology review. The liquid metal compatibility study evaluated process parameters for use in the Stirling power converter. The alternative joining techniques study looked at the applicability of various joining techniques to the Stirling power converter requirements.

A Data-Driven Design Evaluation Tool for Handheld Device Soft Keyboards

PubMed Central

Trudeau, Matthieu B.; Sunderland, Elsie M.; Jindrich, Devin L.; Dennerlein, Jack T.

2014-01-01

Thumb interaction is a primary technique used to operate small handheld devices such as smartphones. Despite the different techniques involved in operating a handheld device compared to a personal computer, the keyboard layouts for both devices are similar. A handheld device keyboard that considers the physical capabilities of the thumb may improve user experience. We developed and applied a design evaluation tool for different geometries of the QWERTY keyboard using a performance evaluation model. The model utilizes previously collected data on thumb motor performance and posture for different tap locations and thumb movement directions. We calculated a performance index (PITOT, 0 is worst and 2 is best) for 663 designs consisting in different combinations of three variables: the keyboard's radius of curvature (R) (mm), orientation (O) (°), and vertical location on the screen (L). The current standard keyboard performed poorly (PITOT = 0.28) compared to other designs considered. Keyboard location (L) contributed to the greatest variability in performance out of the three design variables, suggesting that designers should modify this variable first. Performance was greatest for designs in the middle keyboard location. In addition, having a slightly upward curve (R = −20 mm) and orientated perpendicular to the thumb's long axis (O = −20°) improved performance to PITOT = 1.97. Poorest performances were associated with placement of the keyboard's spacebar in the bottom right corner of the screen (e.g., the worst was for R = 20 mm, O = 40°, L =  Bottom (PITOT = 0.09)). While this evaluation tool can be used in the design process as an ergonomic reference to promote user motor performance, other design variables such as visual access and usability still remain unexplored. PMID:25211465

Micromolded thick PZT sol gel composite structures for ultrasound transducer devices operating at high frequencies

NASA Astrophysics Data System (ADS)

Pang, Guofeng

The objective of this work has been to design and develop a micromolding technique useful for batch fabrication to microfabricate 3D ceramic structures for device purposes using a sol gel composite processing technique and deep photolithography (UV LIGA). These structures may be the elements of ultrasound transducers, the structures associated with electronic packaging, or microstructures for microfluidic applications. To demonstrate the technique, the project has focused on the design and fabrication of annular and linear arrays for high frequency (>20 MHz) ultrasound imaging applications, particularly where an electronically steered imaging modality is employed. Other typical micromolded structures have been demonstrated to show the potential for micromolding. The transferability of the technique for industrial purposes is proposed. Using a sol gel composite process, the critical components in this technique are mold making, mold filling, material-processing, demolding, top electrode and essential material characterization. Two types of molds have been created using UV LIGA and/or electroplating. A purely organic mold made of Su-8 epoxy based photo-resist has shown tremendous performance for micromolding. The transducer packaging process has also been designed and evaluated at the laboratory level. A Su-8 micro bridge and bond pad has been used for wire bonding purposes. A 5-element annular array transducer has been fabricated by this technique and fully packaged. The micromolded piezoceramic structures have been characterized. The pulse echo performance of each element and the focusing performance of 5 elements of a packaged transducer array have been evaluated using a coaxial cable and a cable delay system.

[Comparative study of the biometric measurements made by immersion and contact techniques].

PubMed

Kronbauer, Airton Leite; Kronbauer, Fernando Leite; Kronbauer, Cláudia Leite

2006-01-01

To compare clinical biometric findings between measurements of immersion technique and contact technique. Axial length was measured by A-scan in 120 medical examinations in 60 patients with cataract using a non-contact (immersion) and a contact technique in paired-samples by ultrasound. The mean axial length was found to be 23.19 mm (SD 1.32) with the immersion technique and 22.93 mm (SD 1.32) with the contact technique, using the same transducer probe. The difference of 0.255 mm (SD 0.3) was significant at the 0.01 level. The difference should be taken into account when evaluating the accuracy of IOL calculation. The mean standard deviation between recurrent measures in same eye was found to be 0.04 with the immersion technique and 0.19 with the contact technique. The difference of 0.15 was significant at the 0.01 level. The difference should be taken into account when evaluating the accuracy of reproductivity of technique examination. These data provide benchmark information that can be used to monitor clinical practice and to perform others studies.

Evaluation of a technique to simplify depictions of visually complex aeronautical procedures for NextGen

DOT National Transportation Integrated Search

2013-10-04

Performance based navigation supports the design of more precise flight procedures. However, these new procedures can be visually complex, which may impact the usability of charts that depict the procedures. The purpose of the study was to evaluate w...

Introduction to Psychology and Leadership. Typological Analysis of Student Characteristics: Preliminary Report.

ERIC Educational Resources Information Center

Bessemer, David W.; Shrage, Jules H.

Recommendations for an alternative plan, based on typological analysis techniques, for the evaluation of student characteristics related to media, presentation design, and academic performance are presented. Difficulties with present evaluation plans are discussed, and different methods of typological analysis are described. Included are…

Phased models for evaluating the performability of computing systems

NASA Technical Reports Server (NTRS)

Wu, L. T.; Meyer, J. F.

1979-01-01

A phase-by-phase modelling technique is introduced to evaluate a fault tolerant system's ability to execute different sets of computational tasks during different phases of the control process. Intraphase processes are allowed to differ from phase to phase. The probabilities of interphase state transitions are specified by interphase transition matrices. Based on constraints imposed on the intraphase and interphase transition probabilities, various iterative solution methods are developed for calculating system performability.

SIRU utilization. Volume 1: Theory, development and test evaluation

NASA Technical Reports Server (NTRS)

Musoff, H.

1974-01-01

The theory, development, and test evaluations of the Strapdown Inertial Reference Unit (SIRU) are discussed. The statistical failure detection and isolation, single position calibration, and self alignment techniques are emphasized. Circuit diagrams of the system components are provided. Mathematical models are developed to show the performance characteristics of the subsystems. Specific areas of the utilization program are identified as: (1) error source propagation characteristics and (2) local level navigation performance demonstrations.

Reliability studies of Integrated Modular Engine system designs

NASA Technical Reports Server (NTRS)

Hardy, Terry L.; Rapp, Douglas C.

1993-01-01

A study was performed to evaluate the reliability of Integrated Modular Engine (IME) concepts. Comparisons were made between networked IME systems and non-networked discrete systems using expander cycle configurations. Both redundant and non-redundant systems were analyzed. Binomial approximation and Markov analysis techniques were employed to evaluate total system reliability. In addition, Failure Modes and Effects Analyses (FMEA), Preliminary Hazard Analyses (PHA), and Fault Tree Analysis (FTA) were performed to allow detailed evaluation of the IME concept. A discussion of these system reliability concepts is also presented.

Reliability studies of integrated modular engine system designs

NASA Technical Reports Server (NTRS)

Hardy, Terry L.; Rapp, Douglas C.

1993-01-01

A study was performed to evaluate the reliability of Integrated Modular Engine (IME) concepts. Comparisons were made between networked IME systems and non-networked discrete systems using expander cycle configurations. Both redundant and non-redundant systems were analyzed. Binomial approximation and Markov analysis techniques were employed to evaluate total system reliability. In addition, Failure Modes and Effects Analyses (FMEA), Preliminary Hazard Analyses (PHA), and Fault Tree Analysis (FTA) were performed to allow detailed evaluation of the IME concept. A discussion of these system reliability concepts is also presented.

Reliability studies of integrated modular engine system designs

NASA Astrophysics Data System (ADS)

Hardy, Terry L.; Rapp, Douglas C.

1993-06-01

A study was performed to evaluate the reliability of Integrated Modular Engine (IME) concepts. Comparisons were made between networked IME systems and non-networked discrete systems using expander cycle configurations. Both redundant and non-redundant systems were analyzed. Binomial approximation and Markov analysis techniques were employed to evaluate total system reliability. In addition, Failure Modes and Effects Analyses (FMEA), Preliminary Hazard Analyses (PHA), and Fault Tree Analysis (FTA) were performed to allow detailed evaluation of the IME concept. A discussion of these system reliability concepts is also presented.

Reliability studies of Integrated Modular Engine system designs

NASA Astrophysics Data System (ADS)

Hardy, Terry L.; Rapp, Douglas C.

1993-06-01

A study was performed to evaluate the reliability of Integrated Modular Engine (IME) concepts. Comparisons were made between networked IME systems and non-networked discrete systems using expander cycle configurations. Both redundant and non-redundant systems were analyzed. Binomial approximation and Markov analysis techniques were employed to evaluate total system reliability. In addition, Failure Modes and Effects Analyses (FMEA), Preliminary Hazard Analyses (PHA), and Fault Tree Analysis (FTA) were performed to allow detailed evaluation of the IME concept. A discussion of these system reliability concepts is also presented.

SU-E-T-433: Field-In-Field Irradiation for Breast Cancer with VERO-4DRT System: A Feasibility Study

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

Hayashi, N; Mizuno, T; Takada, Y

2015-06-15

Purpose: The Vero-4DRT system is a dedicated system for high precision radiation therapy. However, the field size is limited at 15 cm x 15 cm and shapes by using multi-leaf collimator (MLC) without X-Jaw and Y-Jaw. Therefore VERO-4DRT system is not available to simple wedged irradiation for breast cancer. In this study, we suppose FIF with ring and/or tilt/pan angles whole breast irradiation (FIFWBI). The purpose of this study is to verify the feasibility of FIFWBI with VERO-4DRT system. Methods: As fundamental evaluation, we performed commissioning test with phantom. The absorbed dose evaluation at several reference points and dose distributionmore » including split area were performed. We planned 10 demonstrative shapes in phantom for measuring these contents with i-plan workstation (BrainLAB). As clinical evaluation, the dose distribution and dose indexes were evaluated with actual patient data. Five patients with breast cancer were designed FIFWBI radiotherapy plan with split fields. Then, the dose distribution and dose indexes (including Dmax, Dmin, D95, D5 and Homogeneity index) were evaluated in these plans. Results: As the results of fundamental evaluation, all absorbed dose errors between calculated and measured doses were within 2%. The gamma passing rates with 2 mm/3% criteria in all cases were 96±2%. As the results of clinical evaluation, the values of Dmax, D95, D50, D5, and Homogeneity Index were 41.7±0.90 Gy, 49.4±0.34 Gy, 52.26±0.24 Gy, and 1.39±0.03, respectively. For Japanese breast cancer patients, this technique was feasible. However, the large split region was happened in FIFWBI in case of patient with large breast. Conclusion: We evaluated the FIFWBI technique with VERO-4DRT system. This technique is feasible for Japanese patients, but the patient with large breast should be disagreed with this technique.« less

Performability evaluation of the SIFT computer

NASA Technical Reports Server (NTRS)

Meyer, J. F.; Furchtgott, D. G.; Wu, L. T.

1979-01-01

Performability modeling and evaluation techniques are applied to the SIFT computer as it might operate in the computational evironment of an air transport mission. User-visible performance of the total system (SIFT plus its environment) is modeled as a random variable taking values in a set of levels of accomplishment. These levels are defined in terms of four attributes of total system behavior: safety, no change in mission profile, no operational penalties, and no economic process whose states describe the internal structure of SIFT as well as relavant conditions of the environment. Base model state trajectories are related to accomplishment levels via a capability function which is formulated in terms of a 3-level model hierarchy. Performability evaluation algorithms are then applied to determine the performability of the total system for various choices of computer and environment parameter values. Numerical results of those evaluations are presented and, in conclusion, some implications of this effort are discussed.

Performance-Oriented Privacy-Preserving Data Integration

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

Pon, R K; Critchlow, T

2004-09-15

Current solutions to integrating private data with public data have provided useful privacy metrics, such as relative information gain, that can be used to evaluate alternative approaches. Unfortunately, they have not addressed critical performance issues, especially when the public database is very large. The use of hashes and noise yields better performance than existing techniques while still making it difficult for unauthorized entities to distinguish which data items truly exist in the private database. As we show here, leveraging the uncertainty introduced by collisions caused by hashing and the injection of noise, we present a technique for performing a relationalmore » join operation between a massive public table and a relatively smaller private one.« less

Analytical design of an advanced radial turbine. [automobile engines

NASA Technical Reports Server (NTRS)

Large, G. D.; Finger, D. G.; Linder, C. G.

1981-01-01

The aerodynamic and mechanical potential of a single stage ceramic radial inflow turbine was evaluated for a high temperature single stage automotive engine. The aerodynamic analysis utilizes a turbine system optimization technique to evaluate both radial and nonradial rotor blading. Selected turbine rotor configurations were evaluated mechanically with three dimensional finite element techniques. Results indicate that exceptionally high rotor tip speeds (2300 ft/sec) and performance potential are feasible with radial bladed rotors if the projected ceramic material properties are realized. Nonradial rotors reduced tip speed requirements (at constant turbine efficiency) but resulted in a lower cumulative probability of success due to higher blade and disk stresses.

MTF Database: A Repository of Students' Academic Performance Measurements for the Development of Techniques for Evaluating Team Functioning

ERIC Educational Resources Information Center

Hsiung, Chin-Min; Zheng, Xiang-Xiang

2015-01-01

The Measurements for Team Functioning (MTF) database contains a series of student academic performance measurements obtained at a national university in Taiwan. The measurements are acquired from unit tests and homework tests performed during a core mechanical engineering course, and provide an objective means of assessing the functioning of…

DSN telemetry system performance with convolutionally code data

NASA Technical Reports Server (NTRS)

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

1975-01-01

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

Performance evaluation of medical records departments by analytical hierarchy process (AHP) approach in the selected hospitals in Isfahan : medical records dep. & AHP.

PubMed

Ajami, Sima; Ketabi, Saeedeh

2012-06-01

Medical Records Department (MRD) is an important unit for evaluating and planning of care services. The goal of this study is evaluating the performance of the Medical Records Departments (MRDs) of the selected hospitals in Isfahan, Iran by using Analytical Hierarchy Process (AHP). This was an analytic of cross-sectional study that was done in spring 2008 in Isfahan, Iran. The statistical population consisted of MRDs of Alzahra, Kashani and Khorshid Hospitals in Isfahan. Data were collected by forms and through brainstorm technique. To analyze and perform AHP, Expert Choice software was used by researchers. Results were showed archiving unit has received the largest importance weight with respect to information management. However, on customer aspect admission unit has received the largest weight. Ordering weights of Medical Records Departments' Alzahra, Kashani and Khorshid Hospitals in Isfahan were with 0.394, 0.342 and 0.264 respectively. It is useful for managers to allocate and prioritize resources according to AHP technique for ranking at the Medical Records Departments.

Image feature detection and extraction techniques performance evaluation for development of panorama under different light conditions

NASA Astrophysics Data System (ADS)

Patil, Venkat P.; Gohatre, Umakant B.

2018-04-01

The technique of obtaining a wider field-of-view of an image to get high resolution integrated image is normally required for development of panorama of a photographic images or scene from a sequence of part of multiple views. There are various image stitching methods developed recently. For image stitching five basic steps are adopted stitching which are Feature detection and extraction, Image registration, computing homography, image warping and Blending. This paper provides review of some of the existing available image feature detection and extraction techniques and image stitching algorithms by categorizing them into several methods. For each category, the basic concepts are first described and later on the necessary modifications made to the fundamental concepts by different researchers are elaborated. This paper also highlights about the some of the fundamental techniques for the process of photographic image feature detection and extraction methods under various illumination conditions. The Importance of Image stitching is applicable in the various fields such as medical imaging, astrophotography and computer vision. For comparing performance evaluation of the techniques used for image features detection three methods are considered i.e. ORB, SURF, HESSIAN and time required for input images feature detection is measured. Results obtained finally concludes that for daylight condition, ORB algorithm found better due to the fact that less tome is required for more features extracted where as for images under night light condition it shows that SURF detector performs better than ORB/HESSIAN detectors.

Single-pass memory system evaluation for multiprogramming workloads

NASA Technical Reports Server (NTRS)

Conte, Thomas M.; Hwu, Wen-Mei W.

1990-01-01

Modern memory systems are composed of levels of cache memories, a virtual memory system, and a backing store. Varying more than a few design parameters and measuring the performance of such systems has traditionally be constrained by the high cost of simulation. Models of cache performance recently introduced reduce the cost simulation but at the expense of accuracy of performance prediction. Stack-based methods predict performance accurately using one pass over the trace for all cache sizes, but these techniques have been limited to fully-associative organizations. This paper presents a stack-based method of evaluating the performance of cache memories using a recurrence/conflict model for the miss ratio. Unlike previous work, the performance of realistic cache designs, such as direct-mapped caches, are predicted by the method. The method also includes a new approach to the problem of the effects of multiprogramming. This new technique separates the characteristics of the individual program from that of the workload. The recurrence/conflict method is shown to be practical, general, and powerful by comparing its performance to that of a popular traditional cache simulator. The authors expect that the availability of such a tool will have a large impact on future architectural studies of memory systems.

Internal Medicine House Officers' Performance as Assessed by Experts and Standardized Patients.

ERIC Educational Resources Information Center

Calhoun, Judith G.; And Others

1987-01-01

Three chronically ill patients were trained to evaluate the performance of 31 second-year internal medicine house officers based upon: a checklist for the medical data elicited during the medical interview; the process of the interview; and the physical examination technique. (Author/MLW)

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.

Modeling of Convective-Stratiform Precipitation Processes: Sensitivity to Partitioning Methods

NASA Technical Reports Server (NTRS)

Lang, S. E.; Tao, W.-K.; Simpson, J.; Ferrier, B.; Starr, David OC. (Technical Monitor)

2001-01-01

Six different convective-stratiform separation techniques, including a new technique that utilizes the ratio of vertical and terminal velocities, are compared and evaluated using two-dimensional numerical simulations of a tropical [Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA COARE)] and midlatitude continental [Preliminary Regional Experiment for STORM-Central (PRESTORM)] squall line. Comparisons are made in terms of rainfall, cloud coverage, mass fluxes, apparent heating and moistening, mean hydrometeor profiles, CFADs (Contoured Frequency with Altitude Diagrams), microphysics, and latent heating retrieval. Overall, it was found that the different separation techniques produced results that qualitatively agreed. However, the quantitative differences were significant. Observational comparisons were unable to conclusively evaluate the performance of the techniques. Latent heating retrieval was shown to be sensitive to the use of separation technique mainly due to the stratiform region for methods that found very little stratiform rain.

Composing, Analyzing and Validating Software Models

NASA Astrophysics Data System (ADS)

Sheldon, Frederick T.

1998-10-01

This research has been conducted at the Computational Sciences Division of the Information Sciences Directorate at Ames Research Center (Automated Software Engineering Grp). The principle work this summer has been to review and refine the agenda that were carried forward from last summer. Formal specifications provide good support for designing a functionally correct system, however they are weak at incorporating non-functional performance requirements (like reliability). Techniques which utilize stochastic Petri nets (SPNs) are good for evaluating the performance and reliability for a system, but they may be too abstract and cumbersome from the stand point of specifying and evaluating functional behavior. Therefore, one major objective of this research is to provide an integrated approach to assist the user in specifying both functionality (qualitative: mutual exclusion and synchronization) and performance requirements (quantitative: reliability and execution deadlines). In this way, the merits of a powerful modeling technique for performability analysis (using SPNs) can be combined with a well-defined formal specification language. In doing so, we can come closer to providing a formal approach to designing a functionally correct system that meets reliability and performance goals.

Composing, Analyzing and Validating Software Models

NASA Technical Reports Server (NTRS)

Sheldon, Frederick T.

1998-01-01

This research has been conducted at the Computational Sciences Division of the Information Sciences Directorate at Ames Research Center (Automated Software Engineering Grp). The principle work this summer has been to review and refine the agenda that were carried forward from last summer. Formal specifications provide good support for designing a functionally correct system, however they are weak at incorporating non-functional performance requirements (like reliability). Techniques which utilize stochastic Petri nets (SPNs) are good for evaluating the performance and reliability for a system, but they may be too abstract and cumbersome from the stand point of specifying and evaluating functional behavior. Therefore, one major objective of this research is to provide an integrated approach to assist the user in specifying both functionality (qualitative: mutual exclusion and synchronization) and performance requirements (quantitative: reliability and execution deadlines). In this way, the merits of a powerful modeling technique for performability analysis (using SPNs) can be combined with a well-defined formal specification language. In doing so, we can come closer to providing a formal approach to designing a functionally correct system that meets reliability and performance goals.

Five-way smoking status classification using text hot-spot identification and error-correcting output codes.

PubMed

Cohen, Aaron M

2008-01-01

We participated in the i2b2 smoking status classification challenge task. The purpose of this task was to evaluate the ability of systems to automatically identify patient smoking status from discharge summaries. Our submission included several techniques that we compared and studied, including hot-spot identification, zero-vector filtering, inverse class frequency weighting, error-correcting output codes, and post-processing rules. We evaluated our approaches using the same methods as the i2b2 task organizers, using micro- and macro-averaged F1 as the primary performance metric. Our best performing system achieved a micro-F1 of 0.9000 on the test collection, equivalent to the best performing system submitted to the i2b2 challenge. Hot-spot identification, zero-vector filtering, classifier weighting, and error correcting output coding contributed additively to increased performance, with hot-spot identification having by far the largest positive effect. High performance on automatic identification of patient smoking status from discharge summaries is achievable with the efficient and straightforward machine learning techniques studied here.

Effective evaluation of privacy protection techniques in visible and thermal imagery

NASA Astrophysics Data System (ADS)

Nawaz, Tahir; Berg, Amanda; Ferryman, James; Ahlberg, Jörgen; Felsberg, Michael

2017-09-01

Privacy protection may be defined as replacing the original content in an image region with a (less intrusive) content having modified target appearance information to make it less recognizable by applying a privacy protection technique. Indeed, the development of privacy protection techniques also needs to be complemented with an established objective evaluation method to facilitate their assessment and comparison. Generally, existing evaluation methods rely on the use of subjective judgments or assume a specific target type in image data and use target detection and recognition accuracies to assess privacy protection. An annotation-free evaluation method that is neither subjective nor assumes a specific target type is proposed. It assesses two key aspects of privacy protection: "protection" and "utility." Protection is quantified as an appearance similarity, and utility is measured as a structural similarity between original and privacy-protected image regions. We performed an extensive experimentation using six challenging datasets (having 12 video sequences), including a new dataset (having six sequences) that contains visible and thermal imagery. The new dataset is made available online for the community. We demonstrate effectiveness of the proposed method by evaluating six image-based privacy protection techniques and also show comparisons of the proposed method over existing methods.

Evaluation of a satellite laser ranging technique using pseudonoise code modulated laser diodes

NASA Technical Reports Server (NTRS)

Ball, Carolyn Kay

1987-01-01

Several types of Satellite Laser Ranging systems exist, operating with pulsed, high-energy lasers. The distance between a ground point and an orbiting satellite can be determined to within a few centimeters. A new technique substitutes pseudonoise code modulated laser diodes, which are much more compact, reliable and less costly, for the lasers now used. Since laser diode technology is only now achieving sufficiently powerful lasers, the capabilities of the new technique are investigated. Also examined are the effects of using an avalanche photodiode detector instead of a photomultiplier tube. The influence of noise terms (including background radiation, detector dark and thermal noise and speckle) that limit the system range and performance is evaluated.

[An Introduction to A Newly-developed "Acupuncture Needle Manipulation Training-evaluation System" Based on Optical Motion Capture Technique].

PubMed

Zhang, Ao; Yan, Xing-Ke; Liu, An-Guo

2016-12-25

In the present paper, the authors introduce a newly-developed "Acupuncture Needle Manipulation Training-evaluation System" based on optical motion capture technique. It is composed of two parts, sensor and software, and overcomes some shortages of mechanical motion capture technique. This device is able to analyze the data of operations of the pressing-hand and needle-insertion hand during acupuncture performance and its software contains personal computer (PC) version, Android version, and Internetwork Operating System (IOS) Apple version. It is competent in recording and analyzing information of any ope-rator's needling manipulations, and is quite helpful for teachers in teaching, training and examining students in clinical practice.

A literature review on anesthetic practice for carotid endarterectomy surgery based on cost, hemodynamic stability, and neurologic status.

PubMed

Meitzner, Mark C; Skurnowicz, Julie A; Mitchell, Anne

2007-06-01

An extensive literature review was undertaken to evaluate the best anesthetic practice for carotid endarterectomy surgery. Two anesthetic techniques were evaluated: general anesthetic with an endotracheal tube and regional anesthetic block. Three variables were reviewed with respect to significant clinical outcomes based on anesthetic technique. Relevant literature was obtained through multiple sources that included professional journals, a professional website, and textbooks. According to the literature, there is an advantage to performing regional anesthesia with respect to cost and neurologic status. Information analyzed was inconclusive with respect to hemodynamic stability and anesthetic technique. We conclude that regional anesthesia may have some slight advantages; however, more investigation is warranted.

Sentence Similarity Analysis with Applications in Automatic Short Answer Grading

ERIC Educational Resources Information Center

Mohler, Michael A. G.

2012-01-01

In this dissertation, I explore unsupervised techniques for the task of automatic short answer grading. I compare a number of knowledge-based and corpus-based measures of text similarity, evaluate the effect of domain and size on the corpus-based measures, and also introduce a novel technique to improve the performance of the system by integrating…

Development of low cost fabrication techniques for large solid rocket nozzles

NASA Technical Reports Server (NTRS)

Warga, J. J.

1971-01-01

Property measurements and fabrication characteristics were determined and the performance in subscale (Minuteman Wing 2 second stage) motors was evaluated. It was demonstrated that the incorporation of low cost fabrication techniques in a full scale 260 in. nozzle could result in savings of $149,000 when compared with an identical design using tape-wrapped components throughout.

Integral Analysis of Seismic Refraction and Ambient Vibration Survey for Subsurface Profile Evaluation

NASA Astrophysics Data System (ADS)

Hazreek, Z. A. M.; Kamarudin, A. F.; Rosli, S.; Fauziah, A.; Akmal, M. A. K.; Aziman, M.; Azhar, A. T. S.; Ashraf, M. I. M.; Shaylinda, M. Z. N.; Rais, Y.; Ishak, M. F.; Alel, M. N. A.

2018-04-01

Geotechnical site investigation as known as subsurface profile evaluation is the process of subsurface layer characteristics determination which finally used for design and construction phase. Traditionally, site investigation was performed using drilling technique thus suffers from several limitation due to cost, time, data coverage and sustainability. In order to overcome those problems, this study adopted surface techniques using seismic refraction and ambient vibration method for subsurface profile depth evaluation. Seismic refraction data acquisition and processing was performed using ABEM Terraloc and OPTIM software respectively. Meanwhile ambient vibration data acquisition and processing was performed using CityShark II, Lennartz and GEOPSY software respectively. It was found that studied area consist of two layers representing overburden and bedrock geomaterials based on p-wave velocity value (vp = 300 – 2500 m/s and vp > 2500 m/s) and natural frequency value (Fo = 3.37 – 3.90 Hz) analyzed. Further analysis found that both methods show some good similarity in term of depth and thickness with percentage accuracy at 60 – 97%. Consequently, this study has demonstrated that the application of seismic refractin and ambient vibration method was applicable in subsurface profile depth and thickness estimation. Moreover, surface technique which consider as non-destructive method adopted in this study was able to compliment conventional drilling method in term of cost, time, data coverage and environmental sustainaibility.

A study of FM threshold extension techniques

NASA Technical Reports Server (NTRS)

Arndt, G. D.; Loch, F. J.

1972-01-01

The characteristics of three postdetection threshold extension techniques are evaluated with respect to the ability of such techniques to improve the performance of a phase lock loop demodulator. These techniques include impulse-noise elimination, signal correlation for the detection of impulse noise, and delta modulation signal processing. Experimental results from signal to noise ratio data and bit error rate data indicate that a 2- to 3-decibel threshold extension is readily achievable by using the various techniques. This threshold improvement is in addition to the threshold extension that is usually achieved through the use of a phase lock loop demodulator.

Neutron assay in mixed radiation fields with a 6Li-loaded plastic scintillator

NASA Astrophysics Data System (ADS)

Balmer, M. J. I.; Gamage, K. A. A.; Taylor, G. C.

2015-08-01

A novel technique for assay of thermal and fast neutrons in a 6Li-loaded plastic scintillator is presented. Existing capture-gated thermal neutron detection techniques were evaluated with the 6Li-loaded plastic scintillator studied in this work. Using simulations and experimental work, shortcomings in its performance were highlighted. As a result, it was proposed that by separating the combined fast and thermal neutron events from gamma events, using established pulse shape discrimination techniques, the thermal neutron events could then be assayed. Experiments were conducted at the National Physical Laboratory, Teddington, performing neutron assays with seven different neutron fields using the proposed technique. For each field, thermal and fast neutron content was estimated and were shown to corroborate with the seven synthesised fields.

The Role of Focus Groups with Other Performance Measurement Methods.

ERIC Educational Resources Information Center

Hart, Elizabeth

Huddersfield University Library (England) has undertaken a wide range of evaluative studies of its services and systems, using various data collection techniques such as: user surveys; exit interviews; online and CD-ROM analysis; benchmarking; user groups; staffing and staff development evaluation; suggestion sheets; student project work; group…

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.

Evaluation of various thrust calculation techniques on an F404 engine

NASA Technical Reports Server (NTRS)

Ray, Ronald J.

1990-01-01

In support of performance testing of the X-29A aircraft at the NASA-Ames, various thrust calculation techniques were developed and evaluated for use on the F404-GE-400 engine. The engine was thrust calibrated at NASA-Lewis. Results from these tests were used to correct the manufacturer's in-flight thrust program to more accurately calculate thrust for the specific test engine. Data from these tests were also used to develop an independent, simplified thrust calculation technique for real-time thrust calculation. Comparisons were also made to thrust values predicted by the engine specification model. Results indicate uninstalled gross thrust accuracies on the order of 1 to 4 percent for the various in-flight thrust methods. The various thrust calculations are described and their usage, uncertainty, and measured accuracies are explained. In addition, the advantages of a real-time thrust algorithm for flight test use and the importance of an accurate thrust calculation to the aircraft performance analysis are described. Finally, actual data obtained from flight test are presented.

Electric field feedback for Magneto(elasto)Electric magnetometer development

NASA Astrophysics Data System (ADS)

Yang, M.-T.; Zhuang, X.; Sing, M. Lam Chok; Dolabdjian, C.; Finkel, P.; Li, J.; Viehland, D.

2017-12-01

Magneto(elasto)Electric (ME) sensors based on magnetostrictive-piezoelectric composites have been investigated to evaluate their performances to sense a magnetic signal. Previous results have shown that the dielectric loss noise in the piezoelectric layer exhibits as the dominant intrinsic noise at low frequencies, which limits the sensor performances. Also, it has intrinsically no DC capability. To avoid a part of this limitation, modulation detection methods are evaluated through a frequency up-conversion technique [1-4]. Moreover, classical magnetic field feedback techniques can be used to increase the dynamic range, the sensing stability and the system linearity, too. In this paper, we propose a new method to feedback the system by using both the magneto-capacitance modulation and an electric field feedback technique. Our development shows the feasibility of the method and the results match with the theoretical description and material properties. Even if the present results are not totally satisfactory, they give the proof of concept and yield a way for the development of very low power magnetometers.

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

Ragan, Eric D.; Bowman, Doug A.; Kopper, Regis

Virtual reality training systems are commonly used in a variety of domains, and it is important to understand how the realism of a training simulation influences training effectiveness. The paper presents a framework for evaluating the effects of virtual reality fidelity based on an analysis of a simulation’s display, interaction, and scenario components. Following this framework, we conducted a controlled experiment to test the effects of fidelity on training effectiveness for a visual scanning task. The experiment varied the levels of field of view and visual realism during a training phase and then evaluated scanning performance with the simulator’s highestmore » level of fidelity. To assess scanning performance, we measured target detection and adherence to a prescribed strategy. The results show that both field of view and visual realism significantly affected target detection during training; higher field of view led to better performance and higher visual realism worsened performance. Additionally, the level of visual realism during training significantly affected learning of the prescribed visual scanning strategy, providing evidence that high visual realism was important for learning the technique. The results also demonstrate that task performance during training was not always a sufficient measure of mastery of an instructed technique. That is, if learning a prescribed strategy or skill is the goal of a training exercise, performance in a simulation may not be an appropriate indicator of effectiveness outside of training—evaluation in a more realistic setting may be necessary.« less

Evaluation of a deformable registration algorithm for subsequent lung computed tomography imaging during radiochemotherapy

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

Stützer, Kristin; Haase, Robert; Exner, Florian

2016-09-15

Purpose: Rating both a lung segmentation algorithm and a deformable image registration (DIR) algorithm for subsequent lung computed tomography (CT) images by different evaluation techniques. Furthermore, investigating the relative performance and the correlation of the different evaluation techniques to address their potential value in a clinical setting. Methods: Two to seven subsequent CT images (69 in total) of 15 lung cancer patients were acquired prior, during, and after radiochemotherapy. Automated lung segmentations were compared to manually adapted contours. DIR between the first and all following CT images was performed with a fast algorithm specialized for lung tissue registration, requiring themore » lung segmentation as input. DIR results were evaluated based on landmark distances, lung contour metrics, and vector field inconsistencies in different subvolumes defined by eroding the lung contour. Correlations between the results from the three methods were evaluated. Results: Automated lung contour segmentation was satisfactory in 18 cases (26%), failed in 6 cases (9%), and required manual correction in 45 cases (66%). Initial and corrected contours had large overlap but showed strong local deviations. Landmark-based DIR evaluation revealed high accuracy compared to CT resolution with an average error of 2.9 mm. Contour metrics of deformed contours were largely satisfactory. The median vector length of inconsistency vector fields was 0.9 mm in the lung volume and slightly smaller for the eroded volumes. There was no clear correlation between the three evaluation approaches. Conclusions: Automatic lung segmentation remains challenging but can assist the manual delineation process. Proven by three techniques, the inspected DIR algorithm delivers reliable results for the lung CT data sets acquired at different time points. Clinical application of DIR demands a fast DIR evaluation to identify unacceptable results, for instance, by combining different automated DIR evaluation methods.« less

An evaluation of dynamic mutuality measurements and methods in cyclic time series

NASA Astrophysics Data System (ADS)

Xia, Xiaohua; Huang, Guitian; Duan, Na

2010-12-01

Several measurements and techniques have been developed to detect dynamic mutuality and synchronicity of time series in econometrics. This study aims to compare the performances of five methods, i.e., linear regression, dynamic correlation, Markov switching models, concordance index and recurrence quantification analysis, through numerical simulations. We evaluate the abilities of these methods to capture structure changing and cyclicity in time series and the findings of this paper would offer guidance to both academic and empirical researchers. Illustration examples are also provided to demonstrate the subtle differences of these techniques.

Evaluation of Erosion Potential of Estuarine Sediments in NY/NJ Harbor (Impact of In-Situ Stabilization on the Remediation of Soft Sediments - A preamble to Erosion Testing and Evaluation)

DOT National Transportation Integrated Search

2011-09-01

The primary objective of the project are to perform a review of existing in-situ techniques of sediment erosion potential evaluation in contaminated "superfund" sites in the United States and those from Europe and Japan and the applicability of soft ...

Double row equivalent for rotator cuff repair: A biomechanical analysis of a new technique.

PubMed

Robinson, Sean; Krigbaum, Henry; Kramer, Jon; Purviance, Connor; Parrish, Robin; Donahue, Joseph

2018-06-01

There are numerous configurations of double row fixation for rotator cuff tears however, there remains to be a consensus on the best method. In this study, we evaluated three different double-row configurations, including a new method. Our primary question is whether the new anchor and technique compares in biomechanical strength to standard double row techniques. Eighteen prepared fresh frozen bovine infraspinatus tendons were randomized to one of three groups including the New Double Row Equivalent, Arthrex Speedbridge and a transosseous equivalent using standard Stabilynx anchors. Biomechanical testing was performed on humeri sawbones and ultimate load, strain, yield strength, contact area, contact pressure, and a survival plots were evaluated. The new double row equivalent method demonstrated increased survival as well as ultimate strength at 415N compared to the remainder testing groups as well as equivalent contact area and pressure to standard double row techniques. This new anchor system and technique demonstrated higher survival rates and loads to failure than standard double row techniques. This data provides us with a new method of rotator cuff fixation which should be further evaluated in the clinical setting. Basic science biomechanical study.

Performance evaluation of a digital mammography unit using a contrast-detail phantom

NASA Astrophysics Data System (ADS)

Elizalde-Cabrera, J.; Brandan, M.-E.

2015-01-01

The relation between image quality and mean glandular dose (MGD) has been studied for a Senographe 2000D mammographic unit used for research in our laboratory. The magnitudes were evaluated for a clinically relevant range of acrylic thicknesses and radiological techniques. The CDMAM phantom was used to determine the contrast-detail curve. Also, an alternative method based on the analysis of signal-to-noise (SNR) and contrast-to-noise (CNR) ratios from the CDMAM image was proposed and applied. A simple numerical model was utilized to successfully interpret the results. Optimum radiological techniques were determined using the figures-of-merit FOMSNR=SNR2/MGD and FOMCNR=CNR2/MGD. Main results were: the evaluation of the detector response flattening process (it reduces by about one half the spatial non-homogeneities due to the X- ray field), MGD measurements (the values comply with standards), and verification of the automatic exposure control performance (it is sensitive to fluence attenuation, not to contrast). For 4-5 cm phantom thicknesses, the optimum radiological techniques were Rh/Rh 34 kV to optimize SNR, and Rh/Rh 28 kV to optimize CNR.

Properties of hypothesis testing techniques and (Bayesian) model selection for exploration-based and theory-based (order-restricted) hypotheses.

PubMed

Kuiper, Rebecca M; Nederhoff, Tim; Klugkist, Irene

2015-05-01

In this paper, the performance of six types of techniques for comparisons of means is examined. These six emerge from the distinction between the method employed (hypothesis testing, model selection using information criteria, or Bayesian model selection) and the set of hypotheses that is investigated (a classical, exploration-based set of hypotheses containing equality constraints on the means, or a theory-based limited set of hypotheses with equality and/or order restrictions). A simulation study is conducted to examine the performance of these techniques. We demonstrate that, if one has specific, a priori specified hypotheses, confirmation (i.e., investigating theory-based hypotheses) has advantages over exploration (i.e., examining all possible equality-constrained hypotheses). Furthermore, examining reasonable order-restricted hypotheses has more power to detect the true effect/non-null hypothesis than evaluating only equality restrictions. Additionally, when investigating more than one theory-based hypothesis, model selection is preferred over hypothesis testing. Because of the first two results, we further examine the techniques that are able to evaluate order restrictions in a confirmatory fashion by examining their performance when the homogeneity of variance assumption is violated. Results show that the techniques are robust to heterogeneity when the sample sizes are equal. When the sample sizes are unequal, the performance is affected by heterogeneity. The size and direction of the deviations from the baseline, where there is no heterogeneity, depend on the effect size (of the means) and on the trend in the group variances with respect to the ordering of the group sizes. Importantly, the deviations are less pronounced when the group variances and sizes exhibit the same trend (e.g., are both increasing with group number). © 2014 The British Psychological Society.

Novel surgical techniques, regenerative medicine, tissue engineering and innovative immunosuppression in kidney transplantation.

PubMed

Nowacki, Maciej; Nazarewski, Łukasz; Kloskowski, Tomasz; Tyloch, Dominik; Pokrywczyńska, Marta; Pietkun, Katarzyna; Jundziłł, Arkadiusz; Tyloch, Janusz; Habib, Samy L; Drewa, Tomasz

2016-10-01

On the 60 th anniversary of the first successfully performed renal transplantation, we summarize the historical, current and potential future status of kidney transplantation. We discuss three different aspects with a potential significant influence on kidney transplantation progress: the development of surgical techniques, the influence of regenerative medicine and tissue engineering, and changes in immunosuppression. We evaluate the standard open surgical procedures with modern techniques and compare them to less invasive videoscopic as well as robotic techniques. The role of tissue engineering and regenerative medicine as a potential method for future kidney regeneration or replacement and the interesting search for novel solutions in the field of immunosuppression will be discussed. After 60 years since the first successfully performed kidney transplantation, we can conclude that the greatest achievements are associated with the development of surgical techniques and with planned systemic immunosuppression.

Novel surgical techniques, regenerative medicine, tissue engineering and innovative immunosuppression in kidney transplantation

PubMed Central

Nowacki, Maciej; Nazarewski, Łukasz; Tyloch, Dominik; Pokrywczyńska, Marta; Pietkun, Katarzyna; Jundziłł, Arkadiusz; Tyloch, Janusz; Habib, Samy L.; Drewa, Tomasz

2016-01-01

On the 60th anniversary of the first successfully performed renal transplantation, we summarize the historical, current and potential future status of kidney transplantation. We discuss three different aspects with a potential significant influence on kidney transplantation progress: the development of surgical techniques, the influence of regenerative medicine and tissue engineering, and changes in immunosuppression. We evaluate the standard open surgical procedures with modern techniques and compare them to less invasive videoscopic as well as robotic techniques. The role of tissue engineering and regenerative medicine as a potential method for future kidney regeneration or replacement and the interesting search for novel solutions in the field of immunosuppression will be discussed. After 60 years since the first successfully performed kidney transplantation, we can conclude that the greatest achievements are associated with the development of surgical techniques and with planned systemic immunosuppression. PMID:27695507

Characterization and evaluation of an aeolian-photovoltaic system in operation

NASA Astrophysics Data System (ADS)

Bonfatti, F.; Calzolari, P. U.; Cardinali, G. C.; Vivanti, G.; Zani, A.

Data management, analysis techniques and results of performance monitoring of a prototype combined photovoltaic (PV)-wind turbine farm power plant in northern Italy are reported. Emphasis is placed on the PV I-V characteristics and irradiance and cell temperatures. Automated instrumentation monitors and records meteorological data and generator variables such as voltages, currents, output, battery electrolyte temperature, etc. Analysis proceeds by automated selection of I-V data for specific intervals of the year when other variables can be treated as constants. The technique permits characterization of generator performance, adjusting the power plant set points for optimal output, and tracking performance degradation over time.

Stress and Sealing Performance Analysis of Containment Vessel

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

WU, TSU-TE

2005-05-24

This paper presents a numerical technique for analyzing the containment vessel subjected to the combined loading of closure-bolt torque and internal pressure. The detailed stress distributions in the O-rings generated by both the torque load and the internal pressure can be evaluated by using this method. Consequently, the sealing performance of the O-rings can be determined. The material of the O-rings can be represented by any available constitutive equation for hyperelastic material. In the numerical calculation of this paper, the form of the Mooney-Rivlin strain energy potential is used. The technique treats both the preloading process of bolt tightening andmore » the application of internal pressure as slow dynamic loads. Consequently, the problem can be evaluated using explicit numerical integration scheme.« less

Cytotechnologists and On-Site Evaluation of Adequacy

PubMed Central

Collins, Jennifer A.; Novak, Anna; Ali, Syed Z.

2013-01-01

While fine needle aspiration (FNA) is certainly not a new biopsy technique, recent developments in advanced imaging techniques, molecular testing, and targeted therapies have coincided with a rapid increase in the number of FNA procedures being performed. Concurrently, the demand for on-site evaluation of adequacy (OSEA) has also increased, outstripping the capacity of available cytopathologists at some institutions. Among the several alternatives to cytopathologist-performed OSEA, cytotechnologist-attended OSEA stands out because it preserves the representation of the pathology service at the time of the procedure. Herein, we review the current literature about OSEA and the necessity of cytotechnologists to expand access of this useful pathology service to a broader patient population. We also examine how cytotechnologists are likely to fit into the emerging practice of telecytology. PMID:24255627

Hernioscopy: a useful technique for the evaluation of incarcerated hernias that retract under anaesthesia.

PubMed

Morris-Stiff, G; Hassn, A

2008-04-01

The diagnosis of strangulation within an incarcerated abdominal-wall hernia is not always possible preoperatively. In approximately 1% of cases of incarcerated hernias, a strangulated viscus will reduce spontaneously following administration of muscle relaxants during induction of anaesthesia, and the surgeon has to perform an exploratory laparotomy. The aim of this study was to report the use of hernioscopy to inspect intra-abdominal contents and thus prevent unnecessary laparotomy. The case notes of all patients undergoing hernioscopy for incarcerated hernias that reduced spontaneously during induction of anaesthesia, skin incision, or prior to evaluation of sac contents were reviewed. Hernioscopy is performed following insertion of a 10-mm port through the hernia sac. Standard insufflation with carbon dioxide is performed, maintaining an intra-abdominal pressure of 10-12 mmHg following which the laparoscope is inserted and a diagnostic examination performed. Following completion of hernioscopy, the laparoscope is withdrawn, the pneumoperitoneum released, and the hernia repaired in a conventional manner using a tension-free technique. Five patients underwent hernioscopy for the evaluation of incarcerated hernias that had reduced spontaneously prior to inspection of sac contents. There were four men with indirect inguinal hernias and one woman with an incarcerated femoral hernia. The hernioscopy of the four men was unremarkable and they went home the following day. The female patient had blood within the peritoneal cavity arising from the upper abdomen and underwent laparotomy and splenectomy. She made an unremarkable recovery and was discharged on postoperative day 7. Hernioscopy is a simple and useful technique that can be performed by surgeons familiar with laparoscopic procedures such as appendicectomy and cholecystectomy.

Develop Advanced Nonlinear Signal Analysis Topographical Mapping System

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1997-01-01

During the development of the SSME, a hierarchy of advanced signal analysis techniques for mechanical signature analysis has been developed by NASA and AI Signal Research Inc. (ASRI) to improve the safety and reliability for Space Shuttle operations. These techniques can process and identify intelligent information hidden in a measured signal which is often unidentifiable using conventional signal analysis methods. Currently, due to the highly interactive processing requirements and the volume of dynamic data involved, detailed diagnostic analysis is being performed manually which requires immense man-hours with extensive human interface. To overcome this manual process, NASA implemented this program to develop an Advanced nonlinear signal Analysis Topographical Mapping System (ATMS) to provide automatic/unsupervised engine diagnostic capabilities. The ATMS will utilize a rule-based Clips expert system to supervise a hierarchy of diagnostic signature analysis techniques in the Advanced Signal Analysis Library (ASAL). ASAL will perform automatic signal processing, archiving, and anomaly detection/identification tasks in order to provide an intelligent and fully automated engine diagnostic capability. The ATMS has been successfully developed under this contract. In summary, the program objectives to design, develop, test and conduct performance evaluation for an automated engine diagnostic system have been successfully achieved. Software implementation of the entire ATMS system on MSFC's OISPS computer has been completed. The significance of the ATMS developed under this program is attributed to the fully automated coherence analysis capability for anomaly detection and identification which can greatly enhance the power and reliability of engine diagnostic evaluation. The results have demonstrated that ATMS can significantly save time and man-hours in performing engine test/flight data analysis and performance evaluation of large volumes of dynamic test data.

Solar energy system performance evaluation report for IBM System 3, Glendo, Wyoming

NASA Technical Reports Server (NTRS)

1980-01-01

The analysis used was based on instrumented system data monitored and collected for at least one full season of operation. The long-term field performance of the installed system is described. Technical contributions to the definition of techniques and requirements for solar energy system design are given.

National Database Structure for Life Cycle Performance Assessment of Water and Wastewater Rehabilitation Technologies (Retrospective Evaluation)

EPA Science Inventory

This report builds upon a previous pilot study to document the in-service performance of trenchless pipe rehabilitation techniques. The use of pipe rehabilitation and trenchless pipe replacement technologies has increased over the past 30 to 40 years and represents an increasing...

Using Neural Networks to Predict MBA Student Success

ERIC Educational Resources Information Center

Naik, Bijayananda; Ragothaman, Srinivasan

2004-01-01

Predicting MBA student performance for admission decisions is crucial for educational institutions. This paper evaluates the ability of three different models--neural networks, logit, and probit to predict MBA student performance in graduate programs. The neural network technique was used to classify applicants into successful and marginal student…

Evaluation of the Service Review Model with Performance Scorecards

ERIC Educational Resources Information Center

Szabo, Thomas G.; Williams, W. Larry; Rafacz, Sharlet D.; Newsome, William; Lydon, Christina A.

2012-01-01

The current study combined a management technique termed "Service Review" with performance scorecards to enhance staff and consumer behavior in a human service setting consisting of 11 supervisors and 56 front-line staff working with 9 adult consumers with challenging behaviors. Results of our intervention showed that service review and…

Evaluating the Effectiveness of Reference Models in Federating Enterprise Architectures

ERIC Educational Resources Information Center

Wilson, Jeffery A.

2012-01-01

Agencies need to collaborate with each other to perform missions, improve mission performance, and find efficiencies. The ability of individual government agencies to collaborate with each other for mission and business success and efficiency is complicated by the different techniques used to describe their Enterprise Architectures (EAs).…

A new adjustable parallel drill guide for internal fixation of femoral neck fracture: a developmental and experimental study.

PubMed

Yuenyongviwat, Varah; Tuntarattanapong, Pakjai; Tangtrakulwanich, Boonsin

2016-01-11

Internal fixation is one treatment for femoral neck fracture. Some devices and techniques reported improved accuracy and decreased fluoroscopic time. However, these are not widely used nowadays due to the lack of available special instruments and techniques. To improve the surgical procedure, the authors designed a new adjustable drill guide and tested the efficacy of the device. The authors developed a new adjustable drill guide for cannulated screw guide wire insertion for multiple screw fixation. Eight orthopaedic surgeons performed the experimental study to evaluate the efficacy of this device. Each surgeon performed guide wire insertion for multiple screw fixation in six synthetic femurs: three times with the new device and three times with the conventional technique. The fluoroscopic time, operative time and surgeon satisfaction were evaluated. In the operations with the new adjustable drill guide, the fluoroscopic and operative times were significantly lower than the operations with the conventional technique (p < 0.05). The mean score for the level of satisfaction of this device was also statistically significantly better (p = 0.02) than the conventional technique. The fluoroscopic and operative times with the new adjustable drill guide were reduced for multiple screw fixation of femoral neck fracture and the satisfaction of the surgeons was good.

A preclustering-based ensemble learning technique for acute appendicitis diagnoses.

PubMed

Lee, Yen-Hsien; Hu, Paul Jen-Hwa; Cheng, Tsang-Hsiang; Huang, Te-Chia; Chuang, Wei-Yao

2013-06-01

Acute appendicitis is a common medical condition, whose effective, timely diagnosis can be difficult. A missed diagnosis not only puts the patient in danger but also requires additional resources for corrective treatments. An acute appendicitis diagnosis constitutes a classification problem, for which a further fundamental challenge pertains to the skewed outcome class distribution of instances in the training sample. A preclustering-based ensemble learning (PEL) technique aims to address the associated imbalanced sample learning problems and thereby support the timely, accurate diagnosis of acute appendicitis. The proposed PEL technique employs undersampling to reduce the number of majority-class instances in a training sample, uses preclustering to group similar majority-class instances into multiple groups, and selects from each group representative instances to create more balanced samples. The PEL technique thereby reduces potential information loss from random undersampling. It also takes advantage of ensemble learning to improve performance. We empirically evaluate this proposed technique with 574 clinical cases obtained from a comprehensive tertiary hospital in southern Taiwan, using several prevalent techniques and a salient scoring system as benchmarks. The comparative results show that PEL is more effective and less biased than any benchmarks. The proposed PEL technique seems more sensitive to identifying positive acute appendicitis than the commonly used Alvarado scoring system and exhibits higher specificity in identifying negative acute appendicitis. In addition, the sensitivity and specificity values of PEL appear higher than those of the investigated benchmarks that follow the resampling approach. Our analysis suggests PEL benefits from the more representative majority-class instances in the training sample. According to our overall evaluation results, PEL records the best overall performance, and its area under the curve measure reaches 0.619. The PEL technique is capable of addressing imbalanced sample learning associated with acute appendicitis diagnosis. Our evaluation results suggest PEL is less biased toward a positive or negative class than the investigated benchmark techniques. In addition, our results indicate the overall effectiveness of the proposed technique, compared with prevalent scoring systems or salient classification techniques that follow the resampling approach. Copyright © 2013 Elsevier B.V. All rights reserved.

Synchronization techniques for all digital 16-ary QAM receivers operating over land mobile satellite links

NASA Technical Reports Server (NTRS)

Fines, P.; Aghvami, A. H.

1990-01-01

The performance of a low bit rate (64 Kb/s) all digital 16-ary Differentially Encoded Quadrature Amplitude Modulation (16-DEQAM) demodulator operating over a mobile satellite channel, is considered. The synchronization and detection techniques employed to overcome the Rician channel impairments, are described. The acquisition and steady state performance of this modem, are evaluated by computer simulation over AWGN and RICIAN channels. The results verify the suitability of the 16-DEQAM transmission over slowly faded and/or mildly faded channels.

Benchmark Testing of a New 56Fe Evaluation for Criticality Safety Applications

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

Leal, Luiz C; Ivanov, E.

2015-01-01

The SAMMY code was used to evaluate resonance parameters of the 56Fe cross section in the resolved resonance energy range of 0–2 MeV using transmission data, capture, elastic, inelastic, and double differential elastic cross sections. The resonance analysis was performed with the code SAMMY that fits R-matrix resonance parameters using the generalized least-squares technique (Bayes’ theory). The evaluation yielded a set of resonance parameters that reproduced the experimental data very well, along with a resonance parameter covariance matrix for data uncertainty calculations. Benchmark tests were conducted to assess the evaluation performance in benchmark calculations.

Exploring three faint source detections methods for aperture synthesis radio images

NASA Astrophysics Data System (ADS)

Peracaula, M.; Torrent, A.; Masias, M.; Lladó, X.; Freixenet, J.; Martí, J.; Sánchez-Sutil, J. R.; Muñoz-Arjonilla, A. J.; Paredes, J. M.

2015-04-01

Wide-field radio interferometric images often contain a large population of faint compact sources. Due to their low intensity/noise ratio, these objects can be easily missed by automated detection methods, which have been classically based on thresholding techniques after local noise estimation. The aim of this paper is to present and analyse the performance of several alternative or complementary techniques to thresholding. We compare three different algorithms to increase the detection rate of faint objects. The first technique consists of combining wavelet decomposition with local thresholding. The second technique is based on the structural behaviour of the neighbourhood of each pixel. Finally, the third algorithm uses local features extracted from a bank of filters and a boosting classifier to perform the detections. The methods' performances are evaluated using simulations and radio mosaics from the Giant Metrewave Radio Telescope and the Australia Telescope Compact Array. We show that the new methods perform better than well-known state of the art methods such as SEXTRACTOR, SAD and DUCHAMP at detecting faint sources of radio interferometric images.

Proposed evaluation framework for assessing operator performance with multisensor displays

NASA Technical Reports Server (NTRS)

Foyle, David C.

1992-01-01

Despite aggressive work on the development of sensor fusion algorithms and techniques, no formal evaluation procedures have been proposed. Based on existing integration models in the literature, an evaluation framework is developed to assess an operator's ability to use multisensor, or sensor fusion, displays. The proposed evaluation framework for evaluating the operator's ability to use such systems is a normative approach: The operator's performance with the sensor fusion display can be compared to the models' predictions based on the operator's performance when viewing the original sensor displays prior to fusion. This allows for the determination as to when a sensor fusion system leads to: 1) poorer performance than one of the original sensor displays (clearly an undesirable system in which the fused sensor system causes some distortion or interference); 2) better performance than with either single sensor system alone, but at a sub-optimal (compared to the model predictions) level; 3) optimal performance (compared to model predictions); or, 4) super-optimal performance, which may occur if the operator were able to use some highly diagnostic 'emergent features' in the sensor fusion display, which were unavailable in the original sensor displays. An experiment demonstrating the usefulness of the proposed evaluation framework is discussed.

Evaluation of a technique for color correction in restoring anterior teeth.

PubMed

Rauber, Gabrielle Branco; Bernardon, Jussara Karina; Vieira, Luiz Clovis Cardoso; Baratieri, Luiz Narciso

2017-09-01

This study aimed to evaluate the ability of the proposed technique in producing restorations that exhibit mimesis with tooth structure and to define a restorative clinical protocol. For this study a typodont was used. The right upper central incisor with Class IV lesion was restored with the layering technique (reference tooth, RT). For the left upper central incisor with Class IV lesion, six teeth were restored monochromatically (test teeth, TT), using DA3.5 (n = 3) and DA4 (n = 3) composite resins-resulting in six unsatisfactory color restorations. TT were divided into six groups depending on the color of unsatisfactory restoration and preparation depth. First, a preparation was realized on the labial surface with 0.5 mm, 0.7 mm or 1.0 mm of depth. A second preparation was then performed to reproduce the dentinal mamelons. Next, adhesive procedures were performed and the teeth restored. Opaque halo, opalescent halo and vestibular enamel were then reproduced by the addition of different composite resins. The RT and TT were photographed side by side in typodont to obtain six photographic prints. The photographs of the groups were subjected to visual evaluation by 120 volunteers via a questionnaire. Data were analyzed by the prevalence of answers, and Chi-square test was used to investigate the association between variables at .05 significance. Furthermore, ΔE of groups was evaluated in comparison RT. The results demonstrated that the moderate intensity restorations (DA3.5) with depths of 0.5 mm and 0.7 mm had the highest prevalence of acceptance. For severe intensity restorations (DA4), the preparation depth of 1.0 mm obtained better acceptance. The technique was able to modify the final color of Class IV restorations, producing satisfactory color restorations. This technique can be used for color correction in cases of Class IV restorations, in situations where there is no time for immediate layered restoration, and as a restorative technique. © 2017 Wiley Periodicals, Inc.

Mapping chemicals in air using an environmental CAT scanning system: evaluation of algorithms

NASA Astrophysics Data System (ADS)

Samanta, A.; Todd, L. A.

A new technique is being developed which creates near real-time maps of chemical concentrations in air for environmental and occupational environmental applications. This technique, we call Environmental CAT Scanning, combines the real-time measuring technique of open-path Fourier transform infrared spectroscopy with the mapping capabilitites of computed tomography to produce two-dimensional concentration maps. With this system, a network of open-path measurements is obtained over an area; measurements are then processed using a tomographic algorithm to reconstruct the concentrations. This research focussed on the process of evaluating and selecting appropriate reconstruction algorithms, for use in the field, by using test concentration data from both computer simultation and laboratory chamber studies. Four algorithms were tested using three types of data: (1) experimental open-path data from studies that used a prototype opne-path Fourier transform/computed tomography system in an exposure chamber; (2) synthetic open-path data generated from maps created by kriging point samples taken in the chamber studies (in 1), and; (3) synthetic open-path data generated using a chemical dispersion model to create time seires maps. The iterative algorithms used to reconstruct the concentration data were: Algebraic Reconstruction Technique without Weights (ART1), Algebraic Reconstruction Technique with Weights (ARTW), Maximum Likelihood with Expectation Maximization (MLEM) and Multiplicative Algebraic Reconstruction Technique (MART). Maps were evaluated quantitatively and qualitatively. In general, MART and MLEM performed best, followed by ARTW and ART1. However, algorithm performance varied under different contaminant scenarios. This study showed the importance of using a variety of maps, particulary those generated using dispersion models. The time series maps provided a more rigorous test of the algorithms and allowed distinctions to be made among the algorithms. A comprehensive evaluation of algorithms, for the environmental application of tomography, requires the use of a battery of test concentration data before field implementation, which models reality and tests the limits of the algorithms.

The Differential Effects of Elaborate Feedback and Basic Feedback on Student Performance in a Modified, Personalized System of Instruction Course

ERIC Educational Resources Information Center

Chase, Jared A.; Houmanfar, Ramona

2009-01-01

Educators in large-enrollment courses are faced with the challenge of effectively disseminating information to their students to ensure that they learn the content provided. A related issue involves the means by which instructors evaluate student performance. Offering effective forms of performance feedback may be one technique to provide students…

Biomimetic Dissolution: A Tool to Predict Amorphous Solid Dispersion Performance.

PubMed

Puppolo, Michael M; Hughey, Justin R; Dillon, Traciann; Storey, David; Jansen-Varnum, Susan

2017-11-01

The presented study describes the development of a membrane permeation non-sink dissolution method that can provide analysis of complete drug speciation and emulate the in vivo performance of poorly water-soluble Biopharmaceutical Classification System class II compounds. The designed membrane permeation methodology permits evaluation of free/dissolved/unbound drug from amorphous solid dispersion formulations with the use of a two-cell apparatus, biorelevant dissolution media, and a biomimetic polymer membrane. It offers insight into oral drug dissolution, permeation, and absorption. Amorphous solid dispersions of felodipine were prepared by hot melt extrusion and spray drying techniques and evaluated for in vitro performance. Prior to ranking performance of extruded and spray-dried felodipine solid dispersions, optimization of the dissolution methodology was performed for parameters such as agitation rate, membrane type, and membrane pore size. The particle size and zeta potential were analyzed during dissolution experiments to understand drug/polymer speciation and supersaturation sustainment of felodipine solid dispersions. Bland-Altman analysis was performed to measure the agreement or equivalence between dissolution profiles acquired using polymer membranes and porcine intestines and to establish the biomimetic nature of the treated polymer membranes. The utility of the membrane permeation dissolution methodology is seen during the evaluation of felodipine solid dispersions produced by spray drying and hot melt extrusion. The membrane permeation dissolution methodology can suggest formulation performance and be employed as a screening tool for selection of candidates to move forward to pharmacokinetic studies. Furthermore, the presented model is a cost-effective technique.

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.

Advanced crew procedures development techniques

NASA Technical Reports Server (NTRS)

Arbet, J. D.; Benbow, R. L.; Mangiaracina, A. A.; Mcgavern, J. L.; Spangler, M. C.; Tatum, I. C.

1975-01-01

The development of an operational computer program, the Procedures and Performance Program (PPP), is reported which provides a procedures recording and crew/vehicle performance monitoring capability. The PPP provides real time CRT displays and postrun hardcopy of procedures, difference procedures, performance, performance evaluation, and training script/training status data. During post-run, the program is designed to support evaluation through the reconstruction of displays to any point in time. A permanent record of the simulation exercise can be obtained via hardcopy output of the display data, and via magnetic tape transfer to the Generalized Documentation Processor (GDP). Reference procedures data may be transferred from the GDP to the PPP.

[Minimally invasive fasciotomy in the treatment of chronic exertional anterior compartment syndrome of the leg: personal technique].

PubMed

Bramante, Carmelo; Gandolfo, Luigi; Bosco, Vincenzo

2008-01-01

Numerous fasciotomy techniques have been proposed for the treatment of chronic exertional anterior compartment syndrome. In this work we evaluate the efficacy of a personal surgical technique whereby the fasciotomy is performed through a small cutaneous incision using endo mini-shears. From 2004 to 2006 19 patients, all professional skaters, were submitted to bilateral fasciotomy (38 legs). No complications were observed. Only two patients used pain-killers. In the follow-up (12 months), resumption of competitive activity was achieved by the fourth week in 63.2% of cases (12 patients), by the fifth week in 26.3% (5 patients), and by the sixth week in 10.5% (2 patients). All patients achieved sporting performance comparable to that present before the onset of symptoms. There were no recurrences. This technique is relatively simple to perform, is easily repeatable, does not require a long learning curve, is practically complication-free, and is characterised by a virtually painless postoperative course.

Noninvasive in vivo glucose sensing using an iris based technique

NASA Astrophysics Data System (ADS)

Webb, Anthony J.; Cameron, Brent D.

2011-03-01

Physiological glucose monitoring is important aspect in the treatment of individuals afflicted with diabetes mellitus. Although invasive techniques for glucose monitoring are widely available, it would be very beneficial to make such measurements in a noninvasive manner. In this study, a New Zealand White (NZW) rabbit animal model was utilized to evaluate a developed iris-based imaging technique for the in vivo measurement of physiological glucose concentration. The animals were anesthetized with isoflurane and an insulin/dextrose protocol was used to control blood glucose concentration. To further help restrict eye movement, a developed ocular fixation device was used. During the experimental time frame, near infrared illuminated iris images were acquired along with corresponding discrete blood glucose measurements taken with a handheld glucometer. Calibration was performed using an image based Partial Least Squares (PLS) technique. Independent validation was also performed to assess model performance along with Clarke Error Grid Analysis (CEGA). Initial validation results were promising and show that a high percentage of the predicted glucose concentrations are within 20% of the reference values.

Toward Alternative Metrics for Measuring Performance within Operational Contracting Squadrons: An Application of Benchmarking Techniques

DTIC Science & Technology

1993-09-01

and (6) assistance with special problems by the purchasing department (Cavinato, 1987:10). Szilagyi and Wallace state-that an effective performance...Naval Research, November 1975. Szilagyi , Andrew D. Jr. and Marc J. Wallace , Jr. Organizational Behavior and Performance, Santa Monica CA, Goodyear...evaluation systems will the manager be able to achieve the bottom line--organizational effectiveness ( Szilagyi 1980:457). Benefits of Evaluatin2 Performance

Diagnostic Methods for Predicting Performance Impairment Associated with Combat Stress

DTIC Science & Technology

2007-08-01

vision. Participants who wore glasses were excluded, as the frame of eyeglasses interfered with the ability to acquire a signal with the apparatus...TCD in monitoring fitness to perform concurrently with performance, and to explore strategies for using TCD as a predictor of future performance...most effective technique for evaluating whether soldiers are fit for missions requiring sustained attention. The aim of this study was to test

Performance comparison of optical interference cancellation system architectures.

PubMed

Lu, Maddie; Chang, Matt; Deng, Yanhua; Prucnal, Paul R

2013-04-10

The performance of three optics-based interference cancellation systems are compared and contrasted with each other, and with traditional electronic techniques for interference cancellation. The comparison is based on a set of common performance metrics that we have developed for this purpose. It is shown that thorough evaluation of our optical approaches takes into account the traditional notions of depth of cancellation and dynamic range, along with notions of link loss and uniformity of cancellation. Our evaluation shows that our use of optical components affords performance that surpasses traditional electronic approaches, and that the optimal choice for an optical interference canceller requires taking into account the performance metrics discussed in this paper.

Evaluation of new laser spectrometer techniques for in-situ carbon monoxide measurements

NASA Astrophysics Data System (ADS)

Zellweger, C.; Steinbacher, M.; Buchmann, B.

2012-10-01

Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. The current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came to market with promising properties for trace gas analytics. The current study compares three instruments that have recently become commercially available (since 2011) with the best currently available technique (Vacuum UV Fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques perform considerably better compared to previous techniques, although some issues, such as temperature influence and cross sensitivities, need further attention.

Studies of soundings and imagings measurements from geostationary satellites

NASA Technical Reports Server (NTRS)

Suomi, V. E.

1973-01-01

Soundings and imaging measurements from geostationary satellites are presented. The subjects discussed are: (1) meteorological data processing techniques, (2) sun glitter, (3) cloud growth rate study, satellite stability characteristics, and (4) high resolution optics. The use of perturbation technique to obtain the motion of sensors aboard a satellite is described. The most conditions, and measurement errors. Several performance evaluation parameters are proposed.

Adaptive coding of MSS imagery. [Multi Spectral band Scanners

NASA Technical Reports Server (NTRS)

Habibi, A.; Samulon, A. S.; Fultz, G. L.; Lumb, D.

1977-01-01

A number of adaptive data compression techniques are considered for reducing the bandwidth of multispectral data. They include adaptive transform coding, adaptive DPCM, adaptive cluster coding, and a hybrid method. The techniques are simulated and their performance in compressing the bandwidth of Landsat multispectral images is evaluated and compared using signal-to-noise ratio and classification consistency as fidelity criteria.

Upgrading of the micro-marsupialisation technique for the management of mucus extravasation or retention phenomena.

PubMed

Amaral, M B F; de Freitas, J B; Mesquita, R A

2012-12-01

This study evaluated the performance of an upgrading of the micro-marsupialisation technique for the management of mucus extravasation or retention phenomena. This study presents a prospective case series of management of ranulas and mucoceles, with a follow-up ranging from 6 to 18 months. Data included the age and gender of patients, as well as the type, size, and site of lesions, and number of punctures. The treatment performance was evaluated according to: postoperative pain, oedema, secondary infection, clinical healing, retreatment, and recurrence of the lesions. All patients showed clinical healing of the lesions within 30 days after the micro-marsupialisation technique. None of patients presented a recurrence or required retreatment, there was no oedema or infection. No pain, or mild pain was reported by the majority of patients (58.81%). Micro-marsupialisation proved to be a simple, low cost, relatively non-invasive, painless, effective, and low recurrence technique to treat mucus extravasation or retention phenomena. Micro-marsupialisation can be recommended primarily to treat oral ranulas and selected mucoceles. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Determination of a quantitative parameter to evaluate swimming technique based on the maximal tethered swimming test.

PubMed

Soncin, Rafael; Mezêncio, Bruno; Ferreira, Jacielle Carolina; Rodrigues, Sara Andrade; Huebner, Rudolf; Serrão, Julio Cerca; Szmuchrowski, Leszek

2017-06-01

The aim of this study was to propose a new force parameter, associated with swimmers' technique and performance. Twelve swimmers performed five repetitions of 25 m sprint crawl and a tethered swimming test with maximal effort. The parameters calculated were: the mean swimming velocity for crawl sprint, the mean propulsive force of the tethered swimming test as well as an oscillation parameter calculated from force fluctuation. The oscillation parameter evaluates the force variation around the mean force during the tethered test as a measure of swimming technique. Two parameters showed significant correlations with swimming velocity: the mean force during the tethered swimming (r = 0.85) and the product of the mean force square root and the oscillation (r = 0.86). However, the intercept coefficient was significantly different from zero only for the mean force, suggesting that although the correlation coefficient of the parameters was similar, part of the mean velocity magnitude that was not associated with the mean force was associated with the product of the mean force square root and the oscillation. Thus, force fluctuation during tethered swimming can be used as a quantitative index of swimmers' technique.

Fabric phase sorptive extraction: Two practical sample pretreatment techniques for brominated flame retardants in water.

PubMed

Huang, Guiqi; Dong, Sheying; Zhang, Mengfei; Zhang, Haihan; Huang, Tinglin

2016-09-15

Sample pretreatment is the critical section for residue monitoring of hazardous pollutants. In this paper, using the cellulose fabric as host matrix, three extraction sorbents such as poly (tetrahydrofuran) (PTHF), poly (ethylene glycol) (PEG) and poly (dimethyldiphenylsiloxane) (PDMDPS), were prepared on the surface of the cellulose fabric. Two practical extraction techniques including stir bar fabric phase sorptive extraction (stir bar-FPSE) and magnetic stir fabric phase sorptive extraction (magnetic stir-FPSE) have been designed, which allow stirring of fabric phase sorbent during the whole extraction process. In the meantime, three brominated flame retardants (BFRs) [tetrabromobisphenol A (TBBPA), tetrabromobisphenol A bisallylether (TBBPA-BAE), tetrabromobisphenol A bis(2,3-dibromopropyl)ether (TBBPA-BDBPE)] in the water sample were selected as model analytes for the practical evaluation of the proposed two techniques using high-performance liquid chromatography (HPLC). Moreover, various experimental conditions affecting extraction process such as the type of fabric phase, extraction time, the amount of salt and elution conditions were also investigated. Due to the large sorbent loading capacity and unique stirring performance, both techniques possessed high extraction capability and fast extraction equilibrium. Under the optimized conditions, high recoveries (90-99%) and low limits of detection (LODs) (0.01-0.05 μg L(-1)) were achieved. In addition, the reproducibility was obtained by evaluating the intraday and interday precisions with relative standard deviations (RSDs) less than 5.1% and 6.8%, respectively. The results indicated that two pretreatment techniques were promising and practical for monitoring of hazardous pollutants in the water sample. Due to low solvent consumption and high repeated use performance, proposed techniques also could meet green analytical criteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

AUDIOVISUAL RESOURCES ON THE TEACHING PROCESS IN SURGICAL TECHNIQUE

PubMed Central

PUPULIM, Guilherme Luiz Lenzi; IORIS, Rafael Augusto; GAMA, Ricardo Ribeiro; RIBAS, Carmen Australia Paredes Marcondes; MALAFAIA, Osvaldo; GAMA, Mirnaluci

2015-01-01

Background: The development of didactic means to create opportunities to permit complete and repetitive viewing of surgical procedures is of great importance nowadays due to the increasing difficulty of doing in vivo training. Thus, audiovisual resources favor the maximization of living resources used in education, and minimize problems arising only with verbalism. Aim: To evaluate the use of digital video as a pedagogical strategy in surgical technique teaching in medical education. Methods: Cross-sectional study with 48 students of the third year of medicine, when studying in the surgical technique discipline. They were divided into two groups with 12 in pairs, both subject to the conventional method of teaching, and one of them also exposed to alternative method (video) showing the technical details. All students did phlebotomy in the experimental laboratory, with evaluation and assistance of the teacher/monitor while running. Finally, they answered a self-administered questionnaire related to teaching method when performing the operation. Results: Most of those who did not watch the video took longer time to execute the procedure, did more questions and needed more faculty assistance. The total exposed to video followed the chronology of implementation and approved the new method; 95.83% felt able to repeat the procedure by themselves, and 62.5% of those students that only had the conventional method reported having regular capacity of technique assimilation. In both groups mentioned having regular difficulty, but those who have not seen the video had more difficulty in performing the technique. Conclusion: The traditional method of teaching associated with the video favored the ability to understand and transmitted safety, particularly because it is activity that requires technical skill. The technique with video visualization motivated and arouse interest, facilitated the understanding and memorization of the steps for procedure implementation, benefiting the students performance. PMID:26734790

Selection of examples in case-based computer-aided decision systems

PubMed Central

Mazurowski, Maciej A.; Zurada, Jacek M.; Tourassi, Georgia D.

2013-01-01

Case-based computer-aided decision (CB-CAD) systems rely on a database of previously stored, known examples when classifying new, incoming queries. Such systems can be particularly useful since they do not need retraining every time a new example is deposited in the case base. The adaptive nature of case-based systems is well suited to the current trend of continuously expanding digital databases in the medical domain. To maintain efficiency, however, such systems need sophisticated strategies to effectively manage the available evidence database. In this paper, we discuss the general problem of building an evidence database by selecting the most useful examples to store while satisfying existing storage requirements. We evaluate three intelligent techniques for this purpose: genetic algorithm-based selection, greedy selection and random mutation hill climbing. These techniques are compared to a random selection strategy used as the baseline. The study is performed with a previously presented CB-CAD system applied for false positive reduction in screening mammograms. The experimental evaluation shows that when the development goal is to maximize the system’s diagnostic performance, the intelligent techniques are able to reduce the size of the evidence database to 37% of the original database by eliminating superfluous and/or detrimental examples while at the same time significantly improving the CAD system’s performance. Furthermore, if the case-base size is a main concern, the total number of examples stored in the system can be reduced to only 2–4% of the original database without a decrease in the diagnostic performance. Comparison of the techniques shows that random mutation hill climbing provides the best balance between the diagnostic performance and computational efficiency when building the evidence database of the CB-CAD system. PMID:18854606

AMT-200S Motor Glider Parameter and Performance Estimation

NASA Technical Reports Server (NTRS)

Taylor, Brian R.

2011-01-01

Parameter and performance estimation of an instrumented motor glider was conducted at the National Aeronautics and Space Administration Dryden Flight Research Center in order to provide the necessary information to create a simulation of the aircraft. An output-error technique was employed to generate estimates from doublet maneuvers, and performance estimates were compared with results from a well-known flight-test evaluation of the aircraft in order to provide a complete set of data. Aircraft specifications are given along with information concerning instrumentation, flight-test maneuvers flown, and the output-error technique. Discussion of Cramer-Rao bounds based on both white noise and colored noise assumptions is given. Results include aerodynamic parameter and performance estimates for a range of angles of attack.

Rapid Fabrication Techniques for Liquid Rocket Channel Wall Nozzles

NASA Technical Reports Server (NTRS)

Gradl, Paul R.

2016-01-01

The functions of a regeneratively-cooled nozzle are to (1) expand combustion gases to increase exhaust gas velocity while, (2) maintaining adequate wall temperatures to prevent structural failure, and (3) transfer heat from the hot gases to the coolant fluid to promote injector performance and stability. Regeneratively-cooled nozzles are grouped into two categories: tube-wall nozzles and channel wall nozzles. A channel wall nozzle is designed with an internal liner containing a series of integral coolant channels that are closed out with an external jacket. Manifolds are attached at each end of the nozzle to distribute coolant to and away from the channels. A variety of manufacturing techniques have been explored for channel wall nozzles, including state of the art laser-welded closeouts and pressure-assisted braze closeouts. This paper discusses techniques that NASA MSFC is evaluating for rapid fabrication of channel wall nozzles that address liner fabrication, slotting techniques and liner closeout techniques. Techniques being evaluated for liner fabrication include large-scale additive manufacturing of freeform-deposition structures to create the liner blanks. Abrasive water jet milling is being evaluated for cutting the complex coolant channel geometries. Techniques being considered for rapid closeout of the slotted liners include freeform deposition, explosive bonding and Cold Spray. Each of these techniques, development work and results are discussed in further detail in this paper.

Reproduction of 20th century inter- to multi-decadel surface temperature variablilty in radiatively forced coupled climate models

USDA-ARS?s Scientific Manuscript database

Coupled Model Intercomparison Project 3 simulations of surface temperature were evaluated over the period 1902-1999 to assess their ability to reproduce historical temperature variability at 211 global locations. Model performance was evaluated using the running Mann Whitney-Z method, a technique th...

Metabolic Assessment of Suited Mobility Using Functional Tasks

NASA Technical Reports Server (NTRS)

Norcross, J. R.; McFarland, S. M.; Ploutz-Snyder, Robert

2016-01-01

Existing methods for evaluating extravehicular activity (EVA) suit mobility have typically focused on isolated joint range of motion or torque, but these techniques have little to do with how well a crewmember functionally performs in an EVA suit. To evaluate suited mobility at the system level through measuring metabolic cost (MC) of functional tasks.

Evaluation and analysis of non-intrusive techniques for detecting illicit substances

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

Micklich, B.J.; Roche, C.T.; Fink, C.L.

1995-12-31

Argonne National Laboratory (ANL) and the Houston Advanced Research Center (HARC) have been tasked by the Counterdrug Technology Assessment Center of the Office of National Drug Control Policy to conduct evaluations and analyses of technologies for the non-intrusive inspection of containers for illicit substances. These technologies span the range of nuclear, X-ray, and chemical techniques used in nondestructive sample analysis. ANL has performed assessments of nuclear and X-ray inspection concepts and undertaken site visits with developers to understand the capabilities and the range of applicability of candidate systems. ANL and HARC have provided support to law enforcement agencies (LEAs), includingmore » participation in numerous field studies. Both labs have provided staff to assist in the Narcotics Detection Technology Assessment (NDTA) program for evaluating drug detection systems. Also, the two labs are performing studies of drug contamination of currency. HARC has directed technical evaluations of automated ballistics imaging and identification systems under consideration by law enforcement agencies. ANL and HARC have sponsored workshops and a symposium, and are participating in a Non-Intrusive Inspection Study being led by Dynamics Technology, Incorporated.« less

Computed tomography and magnetic resonance imaging in diagnosing hepatocellular carcinoma.

PubMed

Dalla Palma, L; Pozzi-Mucelli, R S

1992-02-01

The evaluation of hepatocellular carcinoma (HCC) is based upon ultrasonography (US) which has proved to have a high sensitivity and is also extremely useful in guiding the percutaneous needle biopsy. The main role of computed tomography (CT) and magnetic resonance imaging (MRI) is to supplement US in evaluating the extent of HCC. The Authors discuss the different techniques of examinations of the liver both for CT and MRI as far as the modalities of contrast enhancement, site of injection, and type of contrast agents are concerned. The differences between low field and high field magnets are also discussed. The main CT and MRI findings are illustrated, depending upon the technique of examination. Finally the role of these techniques is discussed. Based upon personal experience and the data in CT literature, and if performed with updated technology and intraarterial injection (lipiodol), CT is the method of choice in order to supplement US in the evaluation of HCC.

Improving Service Delivery in a County Health Department WIC Clinic: An Application of Statistical Process Control Techniques

PubMed Central

Boe, Debra Thingstad; Parsons, Helen

2009-01-01

Local public health agencies are challenged to continually improve service delivery, yet they frequently operate with constrained resources. Quality improvement methods and techniques such as statistical process control are commonly used in other industries, and they have recently been proposed as a means of improving service delivery and performance in public health settings. We analyzed a quality improvement project undertaken at a local Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) clinic to reduce waiting times and improve client satisfaction with a walk-in nutrition education service. We used statistical process control techniques to evaluate initial process performance, implement an intervention, and assess process improvements. We found that implementation of these techniques significantly reduced waiting time and improved clients' satisfaction with the WIC service. PMID:19608964

An Analytical Approach for Performance Enhancement of FSO Communication System Using Array of Receivers in Adverse Weather Conditions

NASA Astrophysics Data System (ADS)

Nagpal, Shaina; Gupta, Amit

2017-08-01

Free Space Optics (FSO) link exploits the tremendous network capacity and is capable of offering wireless communications similar to communications through optical fibres. However, FSO link is extremely weather dependent and the major effect on FSO links is due to adverse weather conditions like fog and snow. In this paper, an FSO link is designed using an array of receivers. The disparity of the link for very high attenuation conditions due to fog and snow is analysed using aperture averaging technique. Further effect of aperture averaging technique is investigated by comparing the systems using aperture averaging technique with systems not using aperture averaging technique. The performance of proposed model of FSO link has been evaluated in terms of Q factor, bit error rate (BER) and eye diagram.

Digital enhancement of computerized axial tomograms

NASA Technical Reports Server (NTRS)

Roberts, E., Jr.

1978-01-01

A systematic evaluation was conducted of certain digital image enhancement techniques performed in image space. Three types of images were used, computer generated phantoms, tomograms of a synthetic phantom, and axial tomograms of human anatomy containing images of lesions, artificially introduced into the tomograms. Several types of smoothing, sharpening, and histogram modification were explored. It was concluded that the most useful enhancement techniques are a selective smoothing of singular picture elements, combined with contrast manipulation. The most useful tool in applying these techniques is the gray-scale histogram.

Comparison of Image Processing Techniques for Nonviable Tissue Quantification in Late Gadolinium Enhancement Cardiac Magnetic Resonance Images.

PubMed

Carminati, M Chiara; Boniotti, Cinzia; Fusini, Laura; Andreini, Daniele; Pontone, Gianluca; Pepi, Mauro; Caiani, Enrico G

2016-05-01

The aim of this study was to compare the performance of quantitative methods, either semiautomated or automated, for left ventricular (LV) nonviable tissue analysis from cardiac magnetic resonance late gadolinium enhancement (CMR-LGE) images. The investigated segmentation techniques were: (i) n-standard deviations thresholding; (ii) full width at half maximum thresholding; (iii) Gaussian mixture model classification; and (iv) fuzzy c-means clustering. These algorithms were applied either in each short axis slice (single-slice approach) or globally considering the entire short-axis stack covering the LV (global approach). CMR-LGE images from 20 patients with ischemic cardiomyopathy were retrospectively selected, and results from each technique were assessed against manual tracing. All methods provided comparable performance in terms of accuracy in scar detection, computation of local transmurality, and high correlation in scar mass compared with the manual technique. In general, no significant difference between single-slice and global approach was noted. The reproducibility of manual and investigated techniques was confirmed in all cases with slightly lower results for the nSD approach. Automated techniques resulted in accurate and reproducible evaluation of LV scars from CMR-LGE in ischemic patients with performance similar to the manual technique. Their application could minimize user interaction and computational time, even when compared with semiautomated approaches.

Image Transmission through OFDM System under the Influence of AWGN Channel

NASA Astrophysics Data System (ADS)

Krishna, Dharavathu; Anuradha, M. S., Dr.

2017-08-01

OFDM system is one among the modern techniques which is most abundantly used in next generation wireless communication networks for transmitting many forms of digital data in efficient manner than compared with other existing traditional techniques. In this paper, one such kind of a digital data corresponding to a two dimensional (2D) gray-scale image is used to evaluate the functionality and overall performance of an OFDM system under the influence of modeled AWGN channel in MATLAB simulation environment. Within the OFDM system, different configurations of notable modulation techniques such as M-PSK and M-QAM are considered for evaluation of the system and necessary valid conclusions are made from the comparison of several observed MATLAB simulation results.

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

Schaeffel, J.A.; Mullinix, B.R.; Ranson, W.F.

An experimental technique to simulate and evaluate the effects of high concentrations of x-rays resulting from a nuclear detonation on missile structures is presented. Data from 34 tests are included to demonstrate the technique. The effects of variations in the foil thickness, capacitor voltage, and plate thickness on the total impulse and maximum strain in the structure were determined. The experimental technique utilizes a high energy capacitor discharge unit to explode an aluminum foil on the surface of the structure. The structural response is evaluated by optical methods using the grid slope deflection method. The fringe patterns were recorded usingmore » a high-speed framing camera. The data were digitized using an optical comparator with an x-y table. The analysis was performed on a CDC 6600 computer.« less

Graphical Technique to Support the Teaching/Learning Process of Software Process Reference Models

NASA Astrophysics Data System (ADS)

Espinosa-Curiel, Ismael Edrein; Rodríguez-Jacobo, Josefina; Fernández-Zepeda, José Alberto

In this paper, we propose a set of diagrams to visualize software process reference models (PRM). The diagrams, called dimods, are the combination of some visual and process modeling techniques such as rich pictures, mind maps, IDEF and RAD diagrams. We show the use of this technique by designing a set of dimods for the Mexican Software Industry Process Model (MoProSoft). Additionally, we perform an evaluation of the usefulness of dimods. The result of the evaluation shows that dimods may be a support tool that facilitates the understanding, memorization, and learning of software PRMs in both, software development organizations and universities. The results also show that dimods may have advantages over the traditional description methods for these types of models.

A Management System for Computer Performance Evaluation.

DTIC Science & Technology

1981-12-01

AD-AIlS 538 AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOO-ETC F/6 S/1 MANAGEMENT SYSTEM FOR COMPUTER PERFORMANCE EVALUATION. (U DEC 81 H K...release; distribution unlimited. AFIT/GCS/1,Y/81 D)-i PREFACE As an installation manager of a Burroughs 3500 1 erncountered many problems concerning its...techniques to select, and finally, how do I organize the effort. As a manager I felt that I needed a reference or tool that would broaden my OPE

Trans-tracheostomic endoscopy of the larynx in the evaluation of dysphagia

PubMed Central

Ricci Maccarini, A; Stacchini, M; Salsi, D; Pieri, F; Magnani, M; Casolino, D

2007-01-01

Summary Laryngeal endoscopy plays a determinant role in clinical evaluation of dysphagia. The examination is performed by means of a trans-nasal approach with a flexible fiberoptic endoscope, able to visualize the pre- and post-deglutitory steps of the pharyngeal phase of swallowing. In patients with tracheostomy, it is possible to visualize the glottic or neoglottic function during the intra-deglutitory phase, performing the examination through a trans-tracheostomic route. The procedure and indications of this endoscopic technique are described. PMID:18320834

Reliable and valid tools for measuring surgeons' teaching performance: residents' vs. self evaluation.

PubMed

Boerebach, Benjamin C M; Arah, Onyebuchi A; Busch, Olivier R C; Lombarts, Kiki M J M H

2012-01-01

In surgical education, there is a need for educational performance evaluation tools that yield reliable and valid data. This paper describes the development and validation of robust evaluation tools that provide surgeons with insight into their clinical teaching performance. We investigated (1) the reliability and validity of 2 tools for evaluating the teaching performance of attending surgeons in residency training programs, and (2) whether surgeons' self evaluation correlated with the residents' evaluation of those surgeons. We surveyed 343 surgeons and 320 residents as part of a multicenter prospective cohort study of faculty teaching performance in residency training programs. The reliability and validity of the SETQ (System for Evaluation Teaching Qualities) tools were studied using standard psychometric techniques. We then estimated the correlations between residents' and surgeons' evaluations. The response rate was 87% among surgeons and 84% among residents, yielding 2625 residents' evaluations and 302 self evaluations. The SETQ tools yielded reliable and valid data on 5 domains of surgical teaching performance, namely, learning climate, professional attitude towards residents, communication of goals, evaluation of residents, and feedback. The correlations between surgeons' self and residents' evaluations were low, with coefficients ranging from 0.03 for evaluation of residents to 0.18 for communication of goals. The SETQ tools for the evaluation of surgeons' teaching performance appear to yield reliable and valid data. The lack of strong correlations between surgeons' self and residents' evaluations suggest the need for using external feedback sources in informed self evaluation of surgeons. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Evaluation of AL-FEC performance for IP television services QoS

NASA Astrophysics Data System (ADS)

Mammi, E.; Russo, G.; Neri, A.

2010-01-01

The IP television services quality is a critical issue because of the nature of transport infrastructure. Packet loss is the main cause of service degradation in such kind of network platforms. The use of forward error correction (FEC) techniques in the application layer (AL-FEC), between the source of TV service (video server) and the user terminal, seams to be an efficient strategy to counteract packet losses alternatively or in addiction to suitable traffic management policies (only feasible in "managed networks"). A number of AL-FEC techniques have been discussed in literature and proposed for inclusion in TV over IP international standards. In this paper a performance evaluation of the AL-FEC defined in SMPTE 2022-1 standard is presented. Different typical events occurring in IP networks causing different types (in terms of statistic distribution) of IP packet losses have been studied and AL-FEC performance to counteract these kind of losses have been evaluated. The performed analysis has been carried out in view of fulfilling the TV services QoS requirements that are usually very demanding. For managed networks, this paper envisages a strategy to combine the use of AL-FEC with the set-up of a transport quality based on FEC packets prioritization. Promising results regard this kind of strategy have been obtained.

[Evaluation and results of ablative therapies in prostate cancer].

PubMed

Renard-Penna, R; Sanchez-Salas, R; Barret, E; Cosset, J M; de Vergie, S; Sapetti, J; Ingels, A; Gangi, A; Lang, H; Cathelineau, X

2017-11-01

To perform a state of the art about methods of evaluation and present results in ablative therapies for localized prostate cancer. A review of the scientific literature was performed in Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of keywords. Publications obtained were selected based on methodology, language and relevance. After selection, 102 articles were analysed. Analyse the results of ablative therapies is presently difficult considering the heterogeneity of indications, techniques and follow-up. However, results from the most recent and homogeneous studies are encouraging. Oncologically, postoperative biopsies (the most important criteria) are negative (without any tumor cells in the treated area) in 75 to 95%. Functionally, urinary and sexual pre-operative status is spared (or recovered early) in more than 90% of the patients treated. More and more studies underline also the correlation between the results and the technique used considering the volume of the gland and, moreover, the "index lesion" localization. The post-treatment pathological evaluation by biopsies (targeted with MRI or, perhaps in a near future, with innovative ultrasonography) is the corner stone of oncological evaluation of ablative therapies. Ongoing trials will allow to standardize the follow-up and determine the best indication and the best techniques in order to optimize oncological and functional results for each patient treated. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Space station common module power system network topology and hardware development

NASA Technical Reports Server (NTRS)

Landis, D. M.

1985-01-01

Candidate power system newtork topologies for the space station common module are defined and developed and the necessary hardware for test and evaluation is provided. Martin Marietta's approach to performing the proposed program is presented. Performance of the tasks described will assure systematic development and evaluation of program results, and will provide the necessary management tools, visibility, and control techniques for performance assessment. The plan is submitted in accordance with the data requirements given and includes a comprehensive task logic flow diagram, time phased manpower requirements, a program milestone schedule, and detailed descriptions of each program task.

Reducing sedation time for thyroplasty with arytenoid adduction with sequential anesthetic technique.

PubMed

Saadeh, Charles K; Rosero, Eric B; Joshi, Girish P; Ozayar, Esra; Mau, Ted

2017-12-01

To determine the extent to which a sequential anesthetic technique 1) shortens time under sedation for thyroplasty with arytenoid adduction (TP-AA), 2) affects the total operative time, and 3) changes the voice outcome compared to TP-AA performed entirely under sedation/analgesia. Case-control study. A new sequential anesthetic technique of performing most of the TP-AA surgery under general anesthesia (GA), followed by transition to sedation/analgesia (SA) for voice assessment, was developed to achieve smooth emergence from GA. Twenty-five TP-AA cases performed with the sequential GA-SA technique were compared with 25 TP-AA controls performed completely under sedation/analgesia. The primary outcome measure was the time under sedation. Voice improvement, as assessed by Consensus Auditory-Perceptual Evaluation of Voice, and total operative time were secondary outcome measures. With the conventional all-SA anesthetic, the duration of SA was 209 ± 26.3 minutes. With the sequential GA-SA technique, the duration of SA was 79.0 ± 18.9 minutes, a 62.3% reduction (P < 0.0001). There was no significant difference in the total operative time (209.5 vs. 200.9 minutes; P = 0.42) or in voice outcome. This sequential anesthetic technique has been easily adopted by multiple anesthesiologists and nurse anesthetists at our institution. TP-AA is effectively performed under sequential GA-SA technique with a significant reduction in the duration of time under sedation. This allows the surgeon to perform the technically more challenging part of the surgery under GA, without having to contend with variability in patient tolerance for laryngeal manipulation under sedation. 3b. Laryngoscope, 127:2813-2817, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

In vivo experience with peroral endoscopic myotomy: An essential activity for developing the technique in humans.

PubMed

Peñaloza-Ramírez, A; Suárez-Correa, J; Báez-Blanco, J; Sabogal-Gómez, C; Kuan-Casas, H; Sánchez-Pignalosa, C; Aponte-Ordóñez, P

Achalasia is the most widely studied esophageal motility disorder. No treatment has achieved completely satisfactory results. The laparoscopic Heller esophagomyotomy is currently the most accepted technique. With the advent of minimally invasive surgery, the appearance of peroral endoscopic myotomy (POEM) has promising results. The primary aim of our study was to perform peroral endoscopic esophagomyotomy in animal experimentation models to perfect the technique and later apply it to humans. The secondary aims were to evaluate the intraoperative and postoperative complications and to describe the anatomopathologic findings. An experimental study was conducted on 8 live porcine models that were followed for 30 days to identify postoperative complications. Necropsy was then performed to evaluate the histopathologic findings. The international requirements and regulations for animal experimentation were met. The technique was carried out in all the models. There was one intraoperative death. Pneumothorax was observed in 50% of the units in experimentation and subcutaneous cervical emphysema in 75%, with no significant clinical repercussions. Histologic muscle layer (myotomy) involvement was above the gastroesophageal junction in 87% of the cases and below it in 25%. Peroral endoscopic esophagomyotomy is a feasible, albeit complex, procedure that requires advanced training, and thus should be performed in highly specialized centers. Specific skills in advanced therapeutic endoscopic procedures of this type must continue to be developed through continuing education (ideally in in vivo models), to then be performed on humans. Copyright © 2017 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

Damage assessment in reinforced concrete using nonlinear vibration techniques

NASA Astrophysics Data System (ADS)

Van Den Abeele, K.; De Visscher, J.

2000-07-01

Reinforced concrete (RC) structures are subject to microcrack initiation and propagation at load levels far below the actual failure load. In this paper, nonlinear vibration techniques are applied to investigate stages of progressive damage in RC beams induced by static loading tests. At different levels of damage, a modal analysis is carried out, assuming the structure to behave linearly. At the same time, measurement of resonant frequencies and damping ratios as function of vibration amplitude are performed using a frequency domain technique as well as a time domain technique. We compare the results of the linear and nonlinear techniques, and value them against the visual damage evaluation.

Framework for performance evaluation of face, text, and vehicle detection and tracking in video: data, metrics, and protocol.

PubMed

Kasturi, Rangachar; Goldgof, Dmitry; Soundararajan, Padmanabhan; Manohar, Vasant; Garofolo, John; Bowers, Rachel; Boonstra, Matthew; Korzhova, Valentina; Zhang, Jing

2009-02-01

Common benchmark data sets, standardized performance metrics, and baseline algorithms have demonstrated considerable impact on research and development in a variety of application domains. These resources provide both consumers and developers of technology with a common framework to objectively compare the performance of different algorithms and algorithmic improvements. In this paper, we present such a framework for evaluating object detection and tracking in video: specifically for face, text, and vehicle objects. This framework includes the source video data, ground-truth annotations (along with guidelines for annotation), performance metrics, evaluation protocols, and tools including scoring software and baseline algorithms. For each detection and tracking task and supported domain, we developed a 50-clip training set and a 50-clip test set. Each data clip is approximately 2.5 minutes long and has been completely spatially/temporally annotated at the I-frame level. Each task/domain, therefore, has an associated annotated corpus of approximately 450,000 frames. The scope of such annotation is unprecedented and was designed to begin to support the necessary quantities of data for robust machine learning approaches, as well as a statistically significant comparison of the performance of algorithms. The goal of this work was to systematically address the challenges of object detection and tracking through a common evaluation framework that permits a meaningful objective comparison of techniques, provides the research community with sufficient data for the exploration of automatic modeling techniques, encourages the incorporation of objective evaluation into the development process, and contributes useful lasting resources of a scale and magnitude that will prove to be extremely useful to the computer vision research community for years to come.

Effects of Conductor Expressivity on Secondary School Band Members' Performance and Attitudes toward Conducting

ERIC Educational Resources Information Center

Silvey, Brian A.; Koerner, Bryan D.

2016-01-01

We investigated the effects of expressive and unexpressive conducting on secondary school band members' and experts' audio evaluations of band performance expressivity. A conductor, who demonstrated either expressive or unexpressive conducting techniques, led both an eighth-grade and a high school band in four separate "run-throughs" of…

Study of Integrated USV/UUV Observation System Performance in Monterey Bay

DTIC Science & Technology

2017-09-01

5 IV. EXPERIMENTAL SETUP... quasi -stationary at depth in low-current environments. This thesis evaluates the performance of deep sensors in determining behavior of a moving source...acoustic sensors that would be quasi -stationary receivers when in drift mode at depth in low current environments. One key advantage to this technique is

A retrospective evaluation of the performance of liner systems used to rehabilitate municipal gravity sewers

EPA Science Inventory

This paper provides new results gathered as part of a 6-year project funded by the U.S. Environmental Protection Agency (USEPA) to document the in-service performance of trenchless pipe rehabilitation techniques. The results from a pilot study focusing on cured-in-place pipe (CI...

Performance modeling of automated manufacturing systems

NASA Astrophysics Data System (ADS)

Viswanadham, N.; Narahari, Y.

A unified and systematic treatment is presented of modeling methodologies and analysis techniques for performance evaluation of automated manufacturing systems. The book is the first treatment of the mathematical modeling of manufacturing systems. Automated manufacturing systems are surveyed and three principal analytical modeling paradigms are discussed: Markov chains, queues and queueing networks, and Petri nets.

Peer Review of a Formal Verification/Design Proof Methodology

NASA Technical Reports Server (NTRS)

1983-01-01

The role of formal verification techniques in system validation was examined. The value and the state of the art of performance proving for fault-tolerant compuers were assessed. The investigation, development, and evaluation of performance proving tools were reviewed. The technical issues related to proof methodologies are examined. The technical issues discussed are summarized.

The role of laparoscopic Heller myotomy in the treatment of achalasia.

PubMed

Zonca, P; Cambal, M; Labas, P; Hrbaty, B; Jacobi, C A

2014-01-01

To evaluate the results of laparoscopic Heller myotomy in our group of patients. A retrospective clinical trial was carried out to evaluate the indication, technique and controversies of laparoscopic Heller myotomy in the achalasia treatment. The following symptoms were evaluated prior and after Heller myotomy: dysphagia, heartburn, nausea/vomiting after meal and asthma/coughing. The patients were evaluated by the use of Likert score. Statistical analysis was performed by using Student t test. The intra-operative (operation time, intraoperative complications, blood loss, conversion rate), and peri-operative parameters (morbidity, mortality, hospital stay) were evaluated as well. The patients who underwent laparoscopic Heller myotomy were included in the trial. All patients were perioperatively managed by a multidisciplinary team. The evaluation of fourteen patients was performed (average age: 53.2 yrs., eleven men, two women, BMI 23.6 kg/m(2)). The patients were indicated for surgery in all of the stages (I-III). Previous semiconservative therapeutic modalities were performed in thirteen patients. The standard laparoscopic technique for Heller myotomy with semifundoplication was applied. All the observed symptoms were statistically improved after the surgery (p=0.05). The average operating time was 89 minutes. Intraoperative blood loss was below 20 ml. There was no conversion to open surgery. An average hospital stay was 4.3 days. Morbidity was 14.3 % and mortality 0 %. In one patient esophageal mucosa perforation was intra-operatively identified and sutured. Post-operative course in this patient was without any complications. The laparoscopic Heller myotomy has become the "gold standard" procedure for achalasia. It is an excellent method allowing precise operation technique with good visualization of the esophagogastric junction. The operation with this approach is safe, efficient, and with excellent reproducible operative results. The correct and early indication for surgery is crucial. The delayed diagnosis with a late indication for surgery is not an exemption (Tab. 2, Fig. 2, Ref. 36).

Remote Leak Detection: Indirect Thermal Technique

NASA Technical Reports Server (NTRS)

Clements, Sandra

2002-01-01

Remote sensing technologies are being considered for efficient, low cost gas leak detection. Eleven specific techniques have been identified for further study and evaluation of several of these is underway. The Indirect Thermal Technique is one of the techniques that is being explored. For this technique, an infrared camera is used to detect the temperature change of a pipe or fitting at the site of a gas leak. This temperature change is caused by the change in temperature of the gas expanding from the leak site. During the 10-week NFFP program, the theory behind the technique was further developed, experiments were performed to determine the conditions for which the technique might be viable, and a proof-of-concept system was developed and tested in the laboratory.

Sensitivity evaluation of dynamic speckle activity measurements using clustering methods.

PubMed

Etchepareborda, Pablo; Federico, Alejandro; Kaufmann, Guillermo H

2010-07-01

We evaluate and compare the use of competitive neural networks, self-organizing maps, the expectation-maximization algorithm, K-means, and fuzzy C-means techniques as partitional clustering methods, when the sensitivity of the activity measurement of dynamic speckle images needs to be improved. The temporal history of the acquired intensity generated by each pixel is analyzed in a wavelet decomposition framework, and it is shown that the mean energy of its corresponding wavelet coefficients provides a suited feature space for clustering purposes. The sensitivity obtained by using the evaluated clustering techniques is also compared with the well-known methods of Konishi-Fujii, weighted generalized differences, and wavelet entropy. The performance of the partitional clustering approach is evaluated using simulated dynamic speckle patterns and also experimental data.

Principal components technique analysis for vegetation and land use discrimination. [Brazilian cerrados

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Formaggio, A. R.; Dossantos, J. R.; Dias, L. A. V.

1984-01-01

Automatic pre-processing technique called Principal Components (PRINCO) in analyzing LANDSAT digitized data, for land use and vegetation cover, on the Brazilian cerrados was evaluated. The chosen pilot area, 223/67 of MSS/LANDSAT 3, was classified on a GE Image-100 System, through a maximum-likehood algorithm (MAXVER). The same procedure was applied to the PRINCO treated image. PRINCO consists of a linear transformation performed on the original bands, in order to eliminate the information redundancy of the LANDSAT channels. After PRINCO only two channels were used thus reducing computer effort. The original channels and the PRINCO channels grey levels for the five identified classes (grassland, "cerrado", burned areas, anthropic areas, and gallery forest) were obtained through the MAXVER algorithm. This algorithm also presented the average performance for both cases. In order to evaluate the results, the Jeffreys-Matusita distance (JM-distance) between classes was computed. The classification matrix, obtained through MAXVER, after a PRINCO pre-processing, showed approximately the same average performance in the classes separability.

Performance Assessment of Discontinuous Fibers in Fiber Reinforced Concrete: Current State-of-the-Art

DTIC Science & Technology

2017-07-01

this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY...non-destructively evaluate fiber distributions, orientation, and FRC posttest damage. This technique allows for a closer to meso scale investigation...performance all the while optimizing the material and improving desired performance by designing materials based on individual constituent

Evaluating sustainable energy harvesting systems for human implantable sensors

NASA Astrophysics Data System (ADS)

AL-Oqla, Faris M.; Omar, Amjad A.; Fares, Osama

2018-03-01

Achieving most appropriate energy-harvesting technique for human implantable sensors is still challenging for the industry where keen decisions have to be performed. Moreover, the available polymeric-based composite materials are offering plentiful renewable applications that can help sustainable development as being useful for the energy-harvesting systems such as photovoltaic, piezoelectric, thermoelectric devices as well as other energy storage systems. This work presents an expert-based model capable of better evaluating and examining various available renewable energy-harvesting techniques in urban surroundings subject to various technical and economic, often conflicting, criteria. Wide evaluation criteria have been adopted in the proposed model after examining their suitability as well as ensuring the expediency and reliability of the model by worldwide experts' feedback. The model includes establishing an analytic hierarchy structure with simultaneous 12 conflicting factors to establish a systematic road map for designers to better assess such techniques for human implantable medical sensors. The energy-harvesting techniques considered were limited to Wireless, Thermoelectric, Infrared Radiator, Piezoelectric, Magnetic Induction and Electrostatic Energy Harvesters. Results have demonstrated that the best decision was in favour of wireless-harvesting technology for the medical sensors as it is preferable by most of the considered evaluation criteria in the model.

Cockpit System Situational Awareness Modeling Tool

NASA Technical Reports Server (NTRS)

Keller, John; Lebiere, Christian; Shay, Rick; Latorella, Kara

2004-01-01

This project explored the possibility of predicting pilot situational awareness (SA) using human performance modeling techniques for the purpose of evaluating developing cockpit systems. The Improved Performance Research Integration Tool (IMPRINT) was combined with the Adaptive Control of Thought-Rational (ACT-R) cognitive modeling architecture to produce a tool that can model both the discrete tasks of pilots and the cognitive processes associated with SA. The techniques for using this tool to predict SA were demonstrated using the newly developed Aviation Weather Information (AWIN) system. By providing an SA prediction tool to cockpit system designers, cockpit concepts can be assessed early in the design process while providing a cost-effective complement to the traditional pilot-in-the-loop experiments and data collection techniques.

Performance of nanocomposites for preservation of artistic stones

NASA Astrophysics Data System (ADS)

Giancristofaro, Cristina; D'Amato, Rosaria; Caneve, Luisa; Pilloni, Luciano; Rinaldi, Antonio; Persia, Franca

2014-06-01

In this work, the effectiveness of nanocomposite surface treatments as protective systems for artistic stones was evaluated. Pyrolitic silica and titania nanoparticles were dispersed in a commercial silicon-based polymer and applied on marble and travertine samples. Artificial aging processes, both in climatic chamber and in solar box, were carried out to simulate real degradation processes in terms of photo-thermal effects and physical-chemical damage. The performances of the nanocomposites used as consolidant were evaluated comparatively by means of diverse diagnostic techniques, namely: scanning electron microscopy (SEM), laser induced fluorescence (LIF), ultrasonic technique, colorimetry, total immersion water absorption and contact angle. The results show that some properties of conservation materials can be improved by the presences of nanoparticles because they induce substantial changes of surface morphology of the coating layer and counter the physical damage observed during artificial weathering.

Toward detection of marine vehicles on horizon from buoy camera

NASA Astrophysics Data System (ADS)

Fefilatyev, Sergiy; Goldgof, Dmitry B.; Langebrake, Lawrence

2007-10-01

This paper presents a new technique for automatic detection of marine vehicles in open sea from a buoy camera system using computer vision approach. Users of such system include border guards, military, port safety and flow management, sanctuary protection personnel. The system is intended to work autonomously, taking images of the surrounding ocean surface and analyzing them on the subject of presence of marine vehicles. The goal of the system is to detect an approximate window around the ship and prepare the small image for transmission and human evaluation. The proposed computer vision-based algorithm combines horizon detection method with edge detection and post-processing. The dataset of 100 images is used to evaluate the performance of proposed technique. We discuss promising results of ship detection and suggest necessary improvements for achieving better performance.

Prostate cancer detection using machine learning techniques by employing combination of features extracting strategies.

PubMed

Hussain, Lal; Ahmed, Adeel; Saeed, Sharjil; Rathore, Saima; Awan, Imtiaz Ahmed; Shah, Saeed Arif; Majid, Abdul; Idris, Adnan; Awan, Anees Ahmed

2018-02-06

Prostate is a second leading causes of cancer deaths among men. Early detection of cancer can effectively reduce the rate of mortality caused by Prostate cancer. Due to high and multiresolution of MRIs from prostate cancer require a proper diagnostic systems and tools. In the past researchers developed Computer aided diagnosis (CAD) systems that help the radiologist to detect the abnormalities. In this research paper, we have employed novel Machine learning techniques such as Bayesian approach, Support vector machine (SVM) kernels: polynomial, radial base function (RBF) and Gaussian and Decision Tree for detecting prostate cancer. Moreover, different features extracting strategies are proposed to improve the detection performance. The features extracting strategies are based on texture, morphological, scale invariant feature transform (SIFT), and elliptic Fourier descriptors (EFDs) features. The performance was evaluated based on single as well as combination of features using Machine Learning Classification techniques. The Cross validation (Jack-knife k-fold) was performed and performance was evaluated in term of receiver operating curve (ROC) and specificity, sensitivity, Positive predictive value (PPV), negative predictive value (NPV), false positive rate (FPR). Based on single features extracting strategies, SVM Gaussian Kernel gives the highest accuracy of 98.34% with AUC of 0.999. While, using combination of features extracting strategies, SVM Gaussian kernel with texture + morphological, and EFDs + morphological features give the highest accuracy of 99.71% and AUC of 1.00.

Methodology development for evaluation of selective-fidelity rotorcraft simulation

NASA Technical Reports Server (NTRS)

Lewis, William D.; Schrage, D. P.; Prasad, J. V. R.; Wolfe, Daniel

1992-01-01

This paper addressed the initial step toward the goal of establishing performance and handling qualities acceptance criteria for realtime rotorcraft simulators through a planned research effort to quantify the system capabilities of 'selective fidelity' simulators. Within this framework the simulator is then classified based on the required task. The simulator is evaluated by separating the various subsystems (visual, motion, etc.) and applying corresponding fidelity constants based on the specific task. This methodology not only provides an assessment technique, but also provides a technique to determine the required levels of subsystem fidelity for a specific task.

Flexible body stability analysis of Space Shuttle ascent flight control system by using lambda matrix solution techniques

NASA Technical Reports Server (NTRS)

Bown, R. L.; Christofferson, A.; Lardas, M.; Flanders, H.

1980-01-01

A lambda matrix solution technique is being developed to perform an open loop frequency analysis of a high order dynamic system. The procedure evaluates the right and left latent vectors corresponding to the respective latent roots. The latent vectors are used to evaluate the partial fraction expansion formulation required to compute the flexible body open loop feedback gains for the Space Shuttle Digital Ascent Flight Control System. The algorithm is in the final stages of development and will be used to insure that the feedback gains meet the design specification.

Subspace techniques to remove artifacts from EEG: a quantitative analysis.

PubMed

Teixeira, A R; Tome, A M; Lang, E W; Martins da Silva, A

2008-01-01

In this work we discuss and apply projective subspace techniques to both multichannel as well as single channel recordings. The single-channel approach is based on singular spectrum analysis(SSA) and the multichannel approach uses the extended infomax algorithm which is implemented in the opensource toolbox EEGLAB. Both approaches will be evaluated using artificial mixtures of a set of selected EEG signals. The latter were selected visually to contain as the dominant activity one of the characteristic bands of an electroencephalogram (EEG). The evaluation is performed both in the time and frequency domain by using correlation coefficients and coherence function, respectively.

A relative performance analysis of atmospheric Laser Doppler Velocimeter methods.

NASA Technical Reports Server (NTRS)

Farmer, W. M.; Hornkohl, J. O.; Brayton, D. B.

1971-01-01

Evaluation of the effectiveness of atmospheric applications of a Laser Doppler Velocimeter (LDV) at a wavelength of about 0.5 micrometer in conjunction with dual scatter LDV illuminating techniques, or at a wavelength of 10.6 micrometer with local oscillator LDV illuminating techniques. Equations and examples are given to provide a quantitative basis for LDV system selection and performance criteria in atmospheric research. The comparative study shows that specific ranges and conditions exist where performance of one of the methods is superior to that of the other. It is also pointed out that great care must be exercised in choosing system parameters that optimize a particular LDV designed for atmospheric applications.

SNR Improvement of QEPAS System by Preamplifier Circuit Optimization and Frequency Locked Technique

NASA Astrophysics Data System (ADS)

Zhang, Qinduan; Chang, Jun; Wang, Zongliang; Wang, Fupeng; Jiang, Fengting; Wang, Mengyao

2018-06-01

Preamplifier circuit noise is of great importance in quartz enhanced photoacoustic spectroscopy (QEPAS) system. In this paper, several noise sources are evaluated and discussed in detail. Based on the noise characteristics, the corresponding noise reduction method is proposed. In addition, a frequency locked technique is introduced to further optimize the QEPAS system noise and improve signal, which achieves a better performance than the conventional frequency scan method. As a result, the signal-to-noise ratio (SNR) could be increased 14 times by utilizing frequency locked technique and numerical averaging technique in the QEPAS system for water vapor detection.

Effects of Field of View and Visual Complexity on Virtual Reality Training Effectiveness for a Visual Scanning Task

DOE PAGES

Ragan, Eric D.; Bowman, Doug A.; Kopper, Regis; ...

2015-02-13

Virtual reality training systems are commonly used in a variety of domains, and it is important to understand how the realism of a training simulation influences training effectiveness. The paper presents a framework for evaluating the effects of virtual reality fidelity based on an analysis of a simulation’s display, interaction, and scenario components. Following this framework, we conducted a controlled experiment to test the effects of fidelity on training effectiveness for a visual scanning task. The experiment varied the levels of field of view and visual realism during a training phase and then evaluated scanning performance with the simulator’s highestmore » level of fidelity. To assess scanning performance, we measured target detection and adherence to a prescribed strategy. The results show that both field of view and visual realism significantly affected target detection during training; higher field of view led to better performance and higher visual realism worsened performance. Additionally, the level of visual realism during training significantly affected learning of the prescribed visual scanning strategy, providing evidence that high visual realism was important for learning the technique. The results also demonstrate that task performance during training was not always a sufficient measure of mastery of an instructed technique. That is, if learning a prescribed strategy or skill is the goal of a training exercise, performance in a simulation may not be an appropriate indicator of effectiveness outside of training—evaluation in a more realistic setting may be necessary.« less

Long-Term In-Service Monitoring and Performance Assessment of the Main Cables of Long-Span Suspension Bridges

PubMed Central

Deng, Yang; Liu, Yang; Chen, Suren

2017-01-01

Despite the recent developments in structural health monitoring, there remain great challenges for accurately, conveniently, and economically assessing the in-service performance of the main cables for long-span suspension bridges. A long-term structural health monitoring technique is developed to measure the tension force with a conventional sensing technology and further provide the in-service performance assessment strategy of the main cable. The monitoring system adopts conventional vibrating strings transducers to monitor the tension forces of separate cable strands of the main cable in the anchor span. The performance evaluation of the main cable is conducted based on the collected health monitoring data: (1) the measured strand forces are used to derive the overall tension force of a main cable, which is further translated into load bearing capacity assessment using the concept of safety factor; and (2) the proposed technique can also evaluate the uniformity of tension forces from different cable strands. The assessment of uniformity of strand forces of a main cable offers critical information in terms of potential risks of partial damage and performance deterioration of the main cable. The results suggest the proposed low-cost monitoring system is an option to provide approximate estimation of tension forces of main cables for suspension bridges. With the long-term monitoring data, the proposed monitoring-based evaluation methods can further provide critical information to assess the safety and serviceability performance of main cables. PMID:28621743

Long-Term In-Service Monitoring and Performance Assessment of the Main Cables of Long-Span Suspension Bridges.

PubMed

Deng, Yang; Liu, Yang; Chen, Suren

2017-06-16

Despite the recent developments in structural health monitoring, there remain great challenges for accurately, conveniently, and economically assessing the in-service performance of the main cables for long-span suspension bridges. A long-term structural health monitoring technique is developed to measure the tension force with a conventional sensing technology and further provide the in-service performance assessment strategy of the main cable. The monitoring system adopts conventional vibrating strings transducers to monitor the tension forces of separate cable strands of the main cable in the anchor span. The performance evaluation of the main cable is conducted based on the collected health monitoring data: (1) the measured strand forces are used to derive the overall tension force of a main cable, which is further translated into load bearing capacity assessment using the concept of safety factor; and (2) the proposed technique can also evaluate the uniformity of tension forces from different cable strands. The assessment of uniformity of strand forces of a main cable offers critical information in terms of potential risks of partial damage and performance deterioration of the main cable. The results suggest the proposed low-cost monitoring system is an option to provide approximate estimation of tension forces of main cables for suspension bridges. With the long-term monitoring data, the proposed monitoring-based evaluation methods can further provide critical information to assess the safety and serviceability performance of main cables.

A Group Wage Incentive System for Production Workers at Pearl Harbor Naval Shipyard: Test and Evaluation

DTIC Science & Technology

1985-09-01

assume they will result in a sweatshop atmosphere. Workers may have fears that management will tighten standards when performance improves or...the shop’s performance can have a major impact on overall shipyard performance. In addition, the potential for accurate performance measurement was... impact of this experimental productivity improvement technique on participants’ job attitudes is supported in the literature. White et al. (in

Noncontrast-enhanced magnetic resonance renal angiography using a repetitive artery and venous labelling technique at 3 T: comparison with contrast-enhanced magnetic resonance angiography in subjects with normal renal function.

PubMed

Park, Sung Yoon; Kim, Chan Kyo; Kim, EunJu; Park, Byung Kwan

2015-02-01

To investigate the feasibility of noncontrast-enhanced MR angiography (NC-MRA) using the repetitive artery and venous labelling (RAVEL) technique to evaluate renal arteries compared to contrast-enhanced MR angiography (CE-MRA). Twenty-five subjects with normal renal function underwent NC-MRA using a RAVEL technique and CE-MRA at 3 T. Two independent readers analysed the MRA images. Image quality, number of renal arteries, presence or absence of an early branching vessel, and diameter of the main renal arteries were evaluated. The overall image quality of NC-MRA was fair or greater in 88% of right and 92% of left renal arteries, while it was 96% in both sides with CE-MRA. On NC-MRA, the number of renal arteries in all subjects was perfectly predicted by both readers. Sensitivity and specificity for predicting early branching vessels were 82% and 100% for reader 1 and 82% and 95% for reader 2. Inter-modality agreement for comparing the diameters of main renal arteries was good or excellent at all segments for both readers. Inter-reader agreement was moderate or good at all segments except at the right distal segment on NC-MRA. NC-MRA with the RAVEL technique at 3 T may have comparable diagnostic feasibility for evaluating renal arteries compared to CE-MRA. • Accurate pre-treatment evaluation of renal artery anatomy helps clinical decision-making. • NC-MRA using RAVEL offers acceptable imaging quality for renal artery evaluation. • The 3 T RAVEL technique provides excellent diagnostic performance for renal artery evaluation. • The 3 T RAVEL technique may be an alternative to contrast-enhanced MRA.

Approximate Computing Techniques for Iterative Graph Algorithms

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

Panyala, Ajay R.; Subasi, Omer; Halappanavar, Mahantesh

Approximate computing enables processing of large-scale graphs by trading off quality for performance. Approximate computing techniques have become critical not only due to the emergence of parallel architectures but also the availability of large scale datasets enabling data-driven discovery. Using two prototypical graph algorithms, PageRank and community detection, we present several approximate computing heuristics to scale the performance with minimal loss of accuracy. We present several heuristics including loop perforation, data caching, incomplete graph coloring and synchronization, and evaluate their efficiency. We demonstrate performance improvements of up to 83% for PageRank and up to 450x for community detection, with lowmore » impact of accuracy for both the algorithms. We expect the proposed approximate techniques will enable scalable graph analytics on data of importance to several applications in science and their subsequent adoption to scale similar graph algorithms.« less

Comparative performance evaluation of transform coding in image pre-processing

NASA Astrophysics Data System (ADS)

Menon, Vignesh V.; NB, Harikrishnan; Narayanan, Gayathri; CK, Niveditha

2017-07-01

We are in the midst of a communication transmute which drives the development as largely as dissemination of pioneering communication systems with ever-increasing fidelity and resolution. Distinguishable researches have been appreciative in image processing techniques crazed by a growing thirst for faster and easier encoding, storage and transmission of visual information. In this paper, the researchers intend to throw light on many techniques which could be worn at the transmitter-end in order to ease the transmission and reconstruction of the images. The researchers investigate the performance of different image transform coding schemes used in pre-processing, their comparison, and effectiveness, the necessary and sufficient conditions, properties and complexity in implementation. Whimsical by prior advancements in image processing techniques, the researchers compare various contemporary image pre-processing frameworks- Compressed Sensing, Singular Value Decomposition, Integer Wavelet Transform on performance. The paper exposes the potential of Integer Wavelet transform to be an efficient pre-processing scheme.

Buried structure for increasing fabrication performance of micromaterial by electromigration

NASA Astrophysics Data System (ADS)

Kimura, Yasuhiro; Saka, Masumi

2016-06-01

The electromigration (EM) technique is a physical synthetic growth method for micro/nanomaterials. EM causes atomic diffusion in a metal line by high-density electron flows. The intentional control of accumulation and relaxation of atoms by EM can lead to the fabrication of a micro/nanomaterial. TiN passivation has been utilized as a component of sample in the EM technique. Although TiN passivation can simplify the cumbersome processes for preparing the sample, the leakage of current naturally occurs because of the conductivity of TiN as a side effect and decreases the performance of micro/nanomaterial fabrication. In the present work, we propose a buried structure, which contributes to significantly decreasing the current for fabricating an Al micromaterial by confining the current flow in the EM technique. The fabrication performance was evaluated based on the threshold current for fabricating an Al micromaterial using the buried structure and the previous structure with the leakage of current.

Evaluation of Neutron Elastic Scatter (NES) technique for detection of graphitic corrosion in gas cast iron pipe. Final report, March 1996-April 1997

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

Charatis, G.; Hugg, E.; McEllistrem, M.

1997-04-01

PENETRON, Inc., in two phases, demonstrated the effectiveness of its Neutron elastic Scatter (NES) techniques in detecting the change in the carbon weight percentage (CWt%) as a measure of corrosion in gray cast iron pipe. In Phase I, experiments were performed with synthetic standards supplied by IIT Research Institute (IITRI) to test the applicability of the NES techniques. Irradiation experiments performed at the University of Kentucky showed that CWt% could be detected, ranging from 1.6% to 13%, within an uncertainty of around 4%. In Phase II, experiments were performed on seven (7) corroded pipe sections supplied by MichCon. Tests weremore » made on pipe sliced lengthwise into quarter sections, and in re-assembled whole pipe sections. X-ray films of the quarter sections indicated probable areas of corrosion for each quarter section.« less

Review of Modelling Techniques for In Vivo Muscle Force Estimation in the Lower Extremities during Strength Training

PubMed Central

Schellenberg, Florian; Oberhofer, Katja; Taylor, William R.

2015-01-01

Background. Knowledge of the musculoskeletal loading conditions during strength training is essential for performance monitoring, injury prevention, rehabilitation, and training design. However, measuring muscle forces during exercise performance as a primary determinant of training efficacy and safety has remained challenging. Methods. In this paper we review existing computational techniques to determine muscle forces in the lower limbs during strength exercises in vivo and discuss their potential for uptake into sports training and rehabilitation. Results. Muscle forces during exercise performance have almost exclusively been analysed using so-called forward dynamics simulations, inverse dynamics techniques, or alternative methods. Musculoskeletal models based on forward dynamics analyses have led to considerable new insights into muscular coordination, strength, and power during dynamic ballistic movement activities, resulting in, for example, improved techniques for optimal performance of the squat jump, while quasi-static inverse dynamics optimisation and EMG-driven modelling have helped to provide an understanding of low-speed exercises. Conclusion. The present review introduces the different computational techniques and outlines their advantages and disadvantages for the informed usage by nonexperts. With sufficient validation and widespread application, muscle force calculations during strength exercises in vivo are expected to provide biomechanically based evidence for clinicians and therapists to evaluate and improve training guidelines. PMID:26417378

Review of Modelling Techniques for In Vivo Muscle Force Estimation in the Lower Extremities during Strength Training.

PubMed

Schellenberg, Florian; Oberhofer, Katja; Taylor, William R; Lorenzetti, Silvio

2015-01-01

Knowledge of the musculoskeletal loading conditions during strength training is essential for performance monitoring, injury prevention, rehabilitation, and training design. However, measuring muscle forces during exercise performance as a primary determinant of training efficacy and safety has remained challenging. In this paper we review existing computational techniques to determine muscle forces in the lower limbs during strength exercises in vivo and discuss their potential for uptake into sports training and rehabilitation. Muscle forces during exercise performance have almost exclusively been analysed using so-called forward dynamics simulations, inverse dynamics techniques, or alternative methods. Musculoskeletal models based on forward dynamics analyses have led to considerable new insights into muscular coordination, strength, and power during dynamic ballistic movement activities, resulting in, for example, improved techniques for optimal performance of the squat jump, while quasi-static inverse dynamics optimisation and EMG-driven modelling have helped to provide an understanding of low-speed exercises. The present review introduces the different computational techniques and outlines their advantages and disadvantages for the informed usage by nonexperts. With sufficient validation and widespread application, muscle force calculations during strength exercises in vivo are expected to provide biomechanically based evidence for clinicians and therapists to evaluate and improve training guidelines.

The effects of spatially displaced visual feedback on remote manipulator performance

NASA Technical Reports Server (NTRS)

Smith, Randy L.; Stuart, Mark A.

1993-01-01

The results of this evaluation have important implications for the arrangement of remote manipulation worksites and the design of workstations for telerobot operations. This study clearly illustrates the deleterious effects that can accompany the performance of remote manipulator tasks when viewing conditions are less than optimal. Future evaluations should emphasize telerobot camera locations and the use of image/graphical enhancement techniques in an attempt to lessen the adverse effects of displaced visual feedback. An important finding in this evaluation is the extent to which results from previously performed direct manipulation studies can be generalized to remote manipulation studies. Even though the results obtained were very similar to those of the direct manipulation evaluations, there were differences as well. This evaluation has demonstrated that generalizations to remote manipulation applications based upon the results of direct manipulation studies are quite useful, but they should be made cautiously.

Application of low-coherence interferometry for in situ nondestructive evaluation of thin and thick multilayered transparent composites

NASA Astrophysics Data System (ADS)

Khomenko, Anton; Cloud, Gary Lee; Haq, Mahmoodul

2015-12-01

Multilayered transparent composites having laminates with polymer interlayers and backing sheets are commonly used in a wide range of applications where visibility, transparency, impact resistance, and safety are essential. Manufacturing flaws or damage during operation can seriously compromise both safety and performance. Most fabrication defects are not discernible until after the entire multilayered transparent composite assembly has been completed, and in-the-field inspection for damage is a problem not yet solved. A robust and reliable nondestructive evaluation (NDE) technique is needed to evaluate structural integrity and identify defects that result from manufacturing issues as well as in-service damage arising from extreme environmental conditions in addition to normal mechanical and thermal loads. Current optical techniques have limited applicability for NDE of such structures. This work presents a technique that employs a modified interferometer utilizing a laser diode or femtosecond fiber laser source to acquire in situ defect depth location inside a thin or thick multilayered transparent composite, respectively. The technique successfully located various defects inside examined composites. The results show great potential of the technique for defect detection, location, and identification in multilayered transparent composites.

Scheduling: A guide for program managers

NASA Technical Reports Server (NTRS)

1994-01-01

The following topics are discussed concerning scheduling: (1) milestone scheduling; (2) network scheduling; (3) program evaluation and review technique; (4) critical path method; (5) developing a network; (6) converting an ugly duckling to a swan; (7) network scheduling problem; (8) (9) network scheduling when resources are limited; (10) multi-program considerations; (11) influence on program performance; (12) line-of-balance technique; (13) time management; (14) recapitulization; and (15) analysis.

Performance evaluation of laser induced breakdown spectroscopy in the measurement of liquid and solid samples

NASA Astrophysics Data System (ADS)

Bilge, Gonca; Sezer, Banu; Boyaci, Ismail Hakki; Eseller, Kemal Efe; Berberoglu, Halil

2018-07-01

Liquid analysis by using LIBS is a complicated process due to difficulties encountered during the collection of light and formation of plasma in liquid. To avoid these, some applications are performed such as aerosol formation and transforming liquid into solid state. However, performance of LIBS in liquid samples still remains a challenging issue. In this study, performance evaluation of LIBS and parameter optimizations in liquid and solid phase samples were performed. For this purpose, milk was chosen as model sample; milk powder was used as solid sample, and milk was used as liquid sample in the experiments. Different experimental setups have been constructed for each sampling technique, and optimizations were performed to determine suitable parameters such as delay time, laser energy, repetition rate and speed of rotary table for solid sampling technique, and flow rate of carrier gas for liquid sampling technique. Target element was determined as Ca, which is a critically important element in milk for determining its nutritional value and Ca addition. In optimum parameters, limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD) values were calculated as 0.11%, 0.36% and 8.29% respectively for milk powders samples; while LOD, LOQ and RSD values were calculated as 0.24%, 0.81%, and 10.93% respectively for milk samples. It can be said that LIBS is an applicable method in both liquid and solid samples with suitable systems and parameters. However, liquid analysis requires much more developed systems for more accurate results.

Reliability-Based Stability Analysis of Rock Slopes Using Numerical Analysis and Response Surface Method

NASA Astrophysics Data System (ADS)

Dadashzadeh, N.; Duzgun, H. S. B.; Yesiloglu-Gultekin, N.

2017-08-01

While advanced numerical techniques in slope stability analysis are successfully used in deterministic studies, they have so far found limited use in probabilistic analyses due to their high computation cost. The first-order reliability method (FORM) is one of the most efficient probabilistic techniques to perform probabilistic stability analysis by considering the associated uncertainties in the analysis parameters. However, it is not possible to directly use FORM in numerical slope stability evaluations as it requires definition of a limit state performance function. In this study, an integrated methodology for probabilistic numerical modeling of rock slope stability is proposed. The methodology is based on response surface method, where FORM is used to develop an explicit performance function from the results of numerical simulations. The implementation of the proposed methodology is performed by considering a large potential rock wedge in Sumela Monastery, Turkey. The accuracy of the developed performance function to truly represent the limit state surface is evaluated by monitoring the slope behavior. The calculated probability of failure is compared with Monte Carlo simulation (MCS) method. The proposed methodology is found to be 72% more efficient than MCS, while the accuracy is decreased with an error of 24%.

RFA Guardian: Comprehensive Simulation of Radiofrequency Ablation Treatment of Liver Tumors.

PubMed

Voglreiter, Philip; Mariappan, Panchatcharam; Pollari, Mika; Flanagan, Ronan; Blanco Sequeiros, Roberto; Portugaller, Rupert Horst; Fütterer, Jurgen; Schmalstieg, Dieter; Kolesnik, Marina; Moche, Michael

2018-01-15

The RFA Guardian is a comprehensive application for high-performance patient-specific simulation of radiofrequency ablation of liver tumors. We address a wide range of usage scenarios. These include pre-interventional planning, sampling of the parameter space for uncertainty estimation, treatment evaluation and, in the worst case, failure analysis. The RFA Guardian is the first of its kind that exhibits sufficient performance for simulating treatment outcomes during the intervention. We achieve this by combining a large number of high-performance image processing, biomechanical simulation and visualization techniques into a generalized technical workflow. Further, we wrap the feature set into a single, integrated application, which exploits all available resources of standard consumer hardware, including massively parallel computing on graphics processing units. This allows us to predict or reproduce treatment outcomes on a single personal computer with high computational performance and high accuracy. The resulting low demand for infrastructure enables easy and cost-efficient integration into the clinical routine. We present a number of evaluation cases from the clinical practice where users performed the whole technical workflow from patient-specific modeling to final validation and highlight the opportunities arising from our fast, accurate prediction techniques.

Evaluating cryostat performance for naval applications

NASA Astrophysics Data System (ADS)

Knoll, David; Willen, Dag; Fesmire, James; Johnson, Wesley; Smith, Jonathan; Meneghelli, Barry; Demko, Jonathan; George, Daniel; Fowler, Brian; Huber, Patti

2012-06-01

The Navy intends to use High Temperature Superconducting Degaussing (HTSDG) coil systems on future Navy platforms. The Navy Metalworking Center (NMC) is leading a team that is addressing cryostat configuration and manufacturing issues associated with fabricating long lengths of flexible, vacuum-jacketed cryostats that meet Navy shipboard performance requirements. The project includes provisions to evaluate the reliability performance, as well as proofing of fabrication techniques. Navy cryostat performance specifications include less than 1 Wm-1 heat loss, 2 MPa working pressure, and a 25-year vacuum life. Cryostat multilayer insulation (MLI) systems developed on the project have been validated using a standardized cryogenic test facility and implemented on 5-meterlong test samples. Performance data from these test samples, which were characterized using both LN2 boiloff and flow-through measurement techniques, will be presented. NMC is working with an Integrated Project Team consisting of Naval Sea Systems Command, Naval Surface Warfare Center-Carderock Division, Southwire Company, nkt cables, Oak Ridge National Laboratory (ORNL), ASRC Aerospace, and NASA Kennedy Space Center (NASA-KSC) to complete these efforts. Approved for public release; distribution is unlimited. This material is submitted with the understanding that right of reproduction for governmental purposes is reserved for the Office of Naval Research, Arlington, Virginia 22203-1995.

A comparison of Chevron and Lindgren-Turan osteotomy techniques in hallux valgus surgery: a prospective randomized controlled study.

PubMed

Uygur, Esat; Özkan, Namık Kemal; Akan, Kaya; Çift, Hakan

2016-01-01

The aim of this prospective randomized controlled single-blind study was to compare the results of Chevron and Lindgren-Turan osteotomy techniques for treatment of moderate hallux valgus. A total of 66 female patients (34 in Chevron group, 32 Lindgren-Turan group) were recruited in this study and followed up for an average of 26.08 months. Operative procedures were performed by 2 surgeons, and patients were evaluated by an another researcher who was blinded to the surgical technique. The groups were compared for their radiological and clinical results. Both techniques was clinically and radiologically effective (p<0.01). However, no significant differences were found between the 2 groups regarding American Orthopaedic Foot and Ankle Society's clinical rating system, Painful Foot Evaluation scale of Maryland University scores, or radiologic evaluation (p>0.05). Compared to the Chevron group, the Lindgren-Turan group was found to have shorter surgical duration (p<0.05) and significantly more shortening at the first metatarsal (p<0.05). In moderate hallux valgus deformity, both the Chevron and Lindgren-Turan osteotomy techniques are clinically and radiologically safe, effective, and reliable alternatives. No superiority was detected in either technique. Although shortening at the first metatarsal in the Lindgren-Turan group was radiologically significant, the results were clinically tolerable.

Multi-time-step ahead daily and hourly intermittent reservoir inflow prediction by artificial intelligent techniques using lumped and distributed data

NASA Astrophysics Data System (ADS)

Jothiprakash, V.; Magar, R. B.

2012-07-01

SummaryIn this study, artificial intelligent (AI) techniques such as artificial neural network (ANN), Adaptive neuro-fuzzy inference system (ANFIS) and Linear genetic programming (LGP) are used to predict daily and hourly multi-time-step ahead intermittent reservoir inflow. To illustrate the applicability of AI techniques, intermittent Koyna river watershed in Maharashtra, India is chosen as a case study. Based on the observed daily and hourly rainfall and reservoir inflow various types of time-series, cause-effect and combined models are developed with lumped and distributed input data. Further, the model performance was evaluated using various performance criteria. From the results, it is found that the performances of LGP models are found to be superior to ANN and ANFIS models especially in predicting the peak inflows for both daily and hourly time-step. A detailed comparison of the overall performance indicated that the combined input model (combination of rainfall and inflow) performed better in both lumped and distributed input data modelling. It was observed that the lumped input data models performed slightly better because; apart from reducing the noise in the data, the better techniques and their training approach, appropriate selection of network architecture, required inputs, and also training-testing ratios of the data set. The slight poor performance of distributed data is due to large variations and lesser number of observed values.

Foveation: an alternative method to simultaneously preserve privacy and information in face images

NASA Astrophysics Data System (ADS)

Alonso, Víctor E.; Enríquez-Caldera, Rogerio; Sucar, Luis Enrique

2017-03-01

This paper presents a real-time foveation technique proposed as an alternative method for image obfuscation while simultaneously preserving privacy in face deidentification. Relevance of the proposed technique is discussed through a comparative study of the most common distortions methods in face images and an assessment on performance and effectiveness of privacy protection. All the different techniques presented here are evaluated when they go through a face recognition software. Evaluating the data utility preservation was carried out under gender and facial expression classification. Results on quantifying the tradeoff between privacy protection and image information preservation at different obfuscation levels are presented. Comparative results using the facial expression subset of the FERET database show that the technique achieves a good tradeoff between privacy and awareness with 30% of recognition rate and a classification accuracy as high as 88% obtained from the common figures of merit using the privacy-awareness map.

Performance evaluation of the atmospheric phase of aeromaneuvering orbital transfer vehicles

NASA Technical Reports Server (NTRS)

Powell, R. W.; Stone, H. W.; Naftel, J. C.

1984-01-01

Studies are underway to design reusable orbital transfer vehicles that would be used to transfer payloads from low-earth orbit to higher orbits and return. One promising concept is to use an atmospheric pass on the return leg to reduce the amount of fuel for the mission. This paper discusses a six-degree-of-freedom simulation analysis for two configurations, a low-lift-to-drag ratio configuration and a medium-lift-to-drag ratio configuration using both a predictive guidance technique and an adaptive guidance technique. Both guidance schemes were evaluated using the 1962 standard atmosphere and three atmospheres that had been derived from three entries of the Space Shuttle. The predictive technique requires less reaction control system activity for both configurations, but because of the limited number of updates and because each update used the 1962 standard atmosphere, the adaptive technique produces more accurate exit conditions.

Single-incision Laparoscopic Surgery (SILS) in general surgery: a review of current practice.

PubMed

Froghi, Farid; Sodergren, Mikael Hans; Darzi, Ara; Paraskeva, Paraskevas

2010-08-01

Single-incision laparoscopic surgery (SILS) aims to eliminate multiple port incisions. Although general operative principles of SILS are similar to conventional laparoscopic surgery, operative techniques are not standardized. This review aims to evaluate the current use of SILS published in the literature by examining the types of operations performed, techniques employed, and relevant complications and morbidity. This review considered a total of 94 studies reporting 1889 patients evaluating 17 different general surgical operations. There were 8 different access techniques reported using conventional laparoscopic instruments and specifically designed SILS ports. There is extensive heterogeneity associated with operating methods and in particular ways of overcoming problems with retraction and instrumentation. Published complications, morbidity, and hospital length of stay are comparable to conventional laparoscopy. Although SILS provides excellent cosmetic results and morbidity seems similar to conventional laparoscopy, larger randomized controlled trials are needed to assess the safety and efficacy of this novel technique.

Definition of mutually optimum NDI and proof test criteria for 2219 aluminum pressure vessels. Volume 3: Applications to rail defect evaluation

NASA Technical Reports Server (NTRS)

Schwartzberg, F. R.; Toth, C., Jr.; King, R. G.; Todd, P. H., Jr.

1979-01-01

The technique for inspection of railroad rails containing transverse fissure defects was discussed. Both pulse-echo and pitch-catch inspection techniques were used. The pulse-echo technique results suggest that a multiple-scan approach using varying angles of inclination, three-surface scanning, and dual-direction traversing may offer promise of characterization of transverse defects. Because each scan is likely to produce a reflection indicating only a portion of the defect, summing of the individual reflections must be used to obtain a reasonably complete characterization of the defect. The ability of the collimated pitch-catch technique to detect relatively small amounts of flaw growth was shown. The method has a problem in characterizing the portions of the defect near the top surface or web intersection. The work performed was a preliminary evaluation of the prospects for automated mapping of rail flaws.

Evaluating structural connectomics in relation to different Q-space sampling techniques.

PubMed

Rodrigues, Paulo; Prats-Galino, Alberto; Gallardo-Pujol, David; Villoslada, Pablo; Falcon, Carles; Prckovska, Vesna

2013-01-01

Brain networks are becoming forefront research in neuroscience. Network-based analysis on the functional and structural connectomes can lead to powerful imaging markers for brain diseases. However, constructing the structural connectome can be based upon different acquisition and reconstruction techniques whose information content and mutual differences has not yet been properly studied in a unified framework. The variations of the structural connectome if not properly understood can lead to dangerous conclusions when performing these type of studies. In this work we present evaluation of the structural connectome by analysing and comparing graph-based measures on real data acquired by the three most important Diffusion Weighted Imaging techniques: DTI, HARDI and DSI. We thus come to several important conclusions demonstrating that even though the different techniques demonstrate differences in the anatomy of the reconstructed fibers the respective connectomes show variations of 20%.

An effective visualization technique for depth perception in augmented reality-based surgical navigation.

PubMed

Choi, Hyunseok; Cho, Byunghyun; Masamune, Ken; Hashizume, Makoto; Hong, Jaesung

2016-03-01

Depth perception is a major issue in augmented reality (AR)-based surgical navigation. We propose an AR and virtual reality (VR) switchable visualization system with distance information, and evaluate its performance in a surgical navigation set-up. To improve depth perception, seamless switching from AR to VR was implemented. In addition, the minimum distance between the tip of the surgical tool and the nearest organ was provided in real time. To evaluate the proposed techniques, five physicians and 20 non-medical volunteers participated in experiments. Targeting error, time taken, and numbers of collisions were measured in simulation experiments. There was a statistically significant difference between a simple AR technique and the proposed technique. We confirmed that depth perception in AR could be improved by the proposed seamless switching between AR and VR, and providing an indication of the minimum distance also facilitated the surgical tasks. Copyright © 2015 John Wiley & Sons, Ltd.

Nondestructive Evaluation (NDE) for Inspection of Composite Sandwich Structures

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Parker, F. Raymond

2014-01-01

Composite honeycomb structures are widely used in aerospace applications due to their low weight and high strength advantages. Developing nondestructive evaluation (NDE) inspection methods are essential for their safe performance. Flash thermography is a commonly used technique for composite honeycomb structure inspections due to its large area and rapid inspection capability. Flash thermography is shown to be sensitive for detection of face sheet impact damage and face sheet to core disbond. Data processing techniques, using principal component analysis to improve the defect contrast, are discussed. Limitations to the thermal detection of the core are investigated. In addition to flash thermography, X-ray computed tomography is used. The aluminum honeycomb core provides excellent X-ray contrast compared to the composite face sheet. The X-ray CT technique was used to detect impact damage, core crushing, and skin to core disbonds. Additionally, the X-ray CT technique is used to validate the thermography results.

Expert system verification and validation study. Delivery 1: Survey and interview questions

NASA Technical Reports Server (NTRS)

1990-01-01

The NASA funded questionnaire is presented to help define the state-of-the-practice in the formal evaluation of Expert Systems on current NASA and industry applications. The answers to this questionnaire, together with follow-up interviews, will provide realistic answers to the following questions: (1) How much evaluation is being performed; (2) What evaluation techniques are in use; and (3) What, if any, are the unique issues in evaluating Expert Systems.

Estimating A Reference Standard Segmentation With Spatially Varying Performance Parameters: Local MAP STAPLE

PubMed Central

Commowick, Olivier; Akhondi-Asl, Alireza; Warfield, Simon K.

2012-01-01

We present a new algorithm, called local MAP STAPLE, to estimate from a set of multi-label segmentations both a reference standard segmentation and spatially varying performance parameters. It is based on a sliding window technique to estimate the segmentation and the segmentation performance parameters for each input segmentation. In order to allow for optimal fusion from the small amount of data in each local region, and to account for the possibility of labels not being observed in a local region of some (or all) input segmentations, we introduce prior probabilities for the local performance parameters through a new Maximum A Posteriori formulation of STAPLE. Further, we propose an expression to compute confidence intervals in the estimated local performance parameters. We carried out several experiments with local MAP STAPLE to characterize its performance and value for local segmentation evaluation. First, with simulated segmentations with known reference standard segmentation and spatially varying performance, we show that local MAP STAPLE performs better than both STAPLE and majority voting. Then we present evaluations with data sets from clinical applications. These experiments demonstrate that spatial adaptivity in segmentation performance is an important property to capture. We compared the local MAP STAPLE segmentations to STAPLE, and to previously published fusion techniques and demonstrate the superiority of local MAP STAPLE over other state-of-the- art algorithms. PMID:22562727

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

An Evaluation Model Applied to a Mathematics-Methods Program Involving Three Characteristics of Teaching Style and Their Relationship to Pupil Achievement. Teacher Education Forum; Volume 3, Number 4.

ERIC Educational Resources Information Center

Dodd, Carol Ann

This study explores a technique for evaluating teacher education programs in terms of teaching competencies, as applied to the Indiana University Mathematics Methods Program (MMP). The evaluation procedures formulated for the study include a process product design in combination with a modification of Pophan's performance test paradigm and Gage's…

Application of basic principles of physics to head and neck MR angiography: troubleshooting for artifacts.

PubMed

Pandey, Shilpa; Hakky, Michael; Kwak, Ellie; Jara, Hernan; Geyer, Carl A; Erbay, Sami H

2013-05-01

Neurovascular imaging studies are routinely used for the assessment of headaches and changes in mental status, stroke workup, and evaluation of the arteriovenous structures of the head and neck. These imaging studies are being performed with greater frequency as the aging population continues to increase. Magnetic resonance (MR) angiographic imaging techniques are helpful in this setting. However, mastering these techniques requires an in-depth understanding of the basic principles of physics, complex flow patterns, and the correlation of MR angiographic findings with conventional MR imaging findings. More than one imaging technique may be used to solve difficult cases, with each technique contributing unique information. Unfortunately, incorporating findings obtained with multiple imaging modalities may add to the diagnostic challenge. To ensure diagnostic accuracy, it is essential that the radiologist carefully evaluate the details provided by these modalities in light of basic physics principles, the fundamentals of various imaging techniques, and common neurovascular imaging pitfalls. ©RSNA, 2013.

Non-destructive evaluation of laboratory scale hydraulic fracturing using acoustic emission

NASA Astrophysics Data System (ADS)

Hampton, Jesse Clay

The primary objective of this research is to develop techniques to characterize hydraulic fractures and fracturing processes using acoustic emission monitoring based on laboratory scale hydraulic fracturing experiments. Individual microcrack AE source characterization is performed to understand the failure mechanisms associated with small failures along pre-existing discontinuities and grain boundaries. Individual microcrack analysis methods include moment tensor inversion techniques to elucidate the mode of failure, crack slip and crack normal direction vectors, and relative volumetric deformation of an individual microcrack. Differentiation between individual microcrack analysis and AE cloud based techniques is studied in efforts to refine discrete fracture network (DFN) creation and regional damage quantification of densely fractured media. Regional damage estimations from combinations of individual microcrack analyses and AE cloud density plotting are used to investigate the usefulness of weighting cloud based AE analysis techniques with microcrack source data. Two granite types were used in several sample configurations including multi-block systems. Laboratory hydraulic fracturing was performed with sample sizes ranging from 15 x 15 x 25 cm3 to 30 x 30 x 25 cm 3 in both unconfined and true-triaxially confined stress states using different types of materials. Hydraulic fracture testing in rock block systems containing a large natural fracture was investigated in terms of AE response throughout fracture interactions. Investigations of differing scale analyses showed the usefulness of individual microcrack characterization as well as DFN and cloud based techniques. Individual microcrack characterization weighting cloud based techniques correlated well with post-test damage evaluations.

Experiences from the anatomy track in the ontology alignment evaluation initiative.

PubMed

Dragisic, Zlatan; Ivanova, Valentina; Li, Huanyu; Lambrix, Patrick

2017-12-04

One of the longest running tracks in the Ontology Alignment Evaluation Initiative is the Anatomy track which focuses on aligning two anatomy ontologies. The Anatomy track was started in 2005. In 2005 and 2006 the task in this track was to align the Foundational Model of Anatomy and the OpenGalen Anatomy Model. Since 2007 the ontologies used in the track are the Adult Mouse Anatomy and a part of the NCI Thesaurus. Since 2015 the data in the Anatomy track is also used in the Interactive track of the Ontology Alignment Evaluation Initiative. In this paper we focus on the Anatomy track in the years 2007-2016 and the Anatomy part of the Interactive track in 2015-2016. We describe the data set and the changes it went through during the years as well as the challenges it poses for ontology alignment systems. Further, we give an overview of all systems that participated in the track and the techniques they have used. We discuss the performance results of the systems and summarize the general trends. About 50 systems have participated in the Anatomy track. Many different techniques were used. The most popular matching techniques are string-based strategies and structure-based techniques. Many systems also use auxiliary information. The quality of the alignment has increased for the best performing systems since the beginning of the track and more and more systems check the coherence of the proposed alignment and implement a repair strategy. Further, interacting with an oracle is beneficial.

Strengthening three-leaf masonry with basalt fibre: Experimental and numerical data

NASA Astrophysics Data System (ADS)

Monni, Francesco; Quagliarini, Enrico; Lenci, Stefano; Maracchini, Gianluca

2017-07-01

This paper presents the first results of a study aimed at evaluate the effectiveness of a strengthening technique able to connect masonry elements, stitching them, based on the use of basalt fibre ropes. To assess the effectiveness of proposed technique, experimental and FEM analysis has been performed. The reproduced masonry is the "three-leaf wall", where an inner core of rubble material is included between two outer brick shell, a masonry typology often found in Italian historical building heritage. The results indicate the efficacy of this dry retrofitting system, increasing the performance of masonry wall specimens.

Sampling methods for microbiological analysis of red meat and poultry carcasses.

PubMed

Capita, Rosa; Prieto, Miguel; Alonso-Calleja, Carlos

2004-06-01

Microbiological analysis of carcasses at slaughterhouses is required in the European Union for evaluating the hygienic performance of carcass production processes as required for effective hazard analysis critical control point implementation. The European Union microbial performance standards refer exclusively to the excision method, even though swabbing using the wet/dry technique is also permitted when correlation between both destructive and nondestructive methods can be established. For practical and economic reasons, the swab technique is the most extensively used carcass surface-sampling method. The main characteristics, advantages, and limitations of the common excision and swabbing methods are described here.

Evaluation of anion exchange resins Tulsion A-30 and Indion-930A by application of radioanalytical technique

NASA Astrophysics Data System (ADS)

Singare, P. U.

2014-07-01

Radioanalytical technique using 131I and 82Br was employed to evaluate organic based anion exchange resins Tulsion A-30 and Indion-930A. The evaluation was based on performance of these resins during iodide and bromide ion-isotopic exchange reactions. It was observed that for iodide ion-isotopic exchange reaction by using Tulsion A-30 resin, the values of specific reaction rate (min-1), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log K d were 0.238, 0.477, 0.114, and 11.0, respectively, which was higher than 0.155, 0.360, 0.056, and 7.3, respectively as that obtained by using Indion-930A resins under identical experimental conditions of 40.0°C, 1.000 g of ion exchange resins and 0.003 M labeled iodide ion solution. Also at a constant temperature of 40.0°C, as the concentration of labeled iodide ion solution increases 0.001 to 0.004 M, for Tulsion A-30 resins the percentage of iodide ions exchanged increases from 59.0 to 65.1%, and from 46.4 to 48.8% for Indion-930A resins under identical experimental conditions. The identical trend was observed for both the resins during bromide ion-isotopic exchange reactions. The overall results indicate that under identical experimental conditions, Tulsion A-30 show superior performance over Indion-930A resins. The results of present experimental work have demonstrated that the radioanalytical technique used here can be successfully applied for characterization of different ion exchange resins so as to evaluate their performance under various process parameters.

Laparoscopic training using a quantitative assessment and instructional system.

PubMed

Yamaguchi, T; Nakamura, R

2018-04-28

Laparoscopic surgery requires complex surgical skills; hence, surgeons require regular training to improve their surgical techniques. The quantitative assessment of a surgeon's skills and the provision of feedback are important processes for conducting effective training. The aim of this study was to develop an inexpensive training system that provides automatic technique evaluation and feedback. We detected the instrument using image processing of commercial web camera images and calculated the motion analysis parameters (MAPs) of the instrument to quantify performance features. Upon receiving the results, we developed a method of evaluating the surgeon's skill level. The feedback system was developed using MAPs-based radar charts and scores for determining the skill level. These methods were evaluated using the videos of 38 surgeons performing a suturing task. There were significant differences in MAPs among surgeons; therefore, MAPs can be effectively used to quantify a surgeon's performance features. The results of skill evaluation and feedback differed greatly between skilled and unskilled surgeons, and it was possible to indicate points of improvement for the procedure performed in this study. Furthermore, the results obtained for certain novice surgeons were similar to those obtained for skilled surgeons. This system can be used to assess the skill level of surgeons, independent of the years of experience, and provide an understanding of the individual's current surgical skill level effectively. We conclude that our system is useful as an inexpensive laparoscopic training system that might aid in skill improvement.

Influence of the operatory field isolation technique on tooth-colored direct dental restorations.

PubMed

Cajazeira, Marlus Roberto Rodrigues; De Sabóia, Ticiana Medeiros; Maia, Lucianne Cople

2014-06-01

To evaluate, through a systematic review, the influence of the operatory field isolation technique on the longevity of dental restorations performed with tooth-colored materials. An electronic search of the scientific databases (MEDLINE, SCIRUS, VHL and SIGLE) and reference lists of the selected articles was conducted to identify randomized controlled clinical trials with a follow-up period of at least 12 months. The selected articles evaluated the effects of the operatory field isolation techniques (rubber dam or cotton rolls/saliva ejector) on the longevity of direct restorations performed with tooth-colored materials (e.g. resin composites, compomers and glass-ionomer cements) in primary or permanent posterior teeth. The selected studies were analyzed and categorized using a checklist proposed by the National Institute for Health and Clinical Excellence of the United Kingdom. 484 studies were identified on the scientific databases. After applying the exclusion criteria and removal of duplicates, a total of nine studies were considered as potentially eligible. From these, five studies were included in the final analysis by two evaluators. In four studies analyzed, the use of rubber dam did not influence the longevity of restorations in comparison to cotton rolls/saliva ejector. Only two studies were considered as low risk of bias.

A simulation-based evaluation of methods for inferring linear barriers to gene flow

Treesearch

Christopher Blair; Dana E. Weigel; Matthew Balazik; Annika T. H. Keeley; Faith M. Walker; Erin Landguth; Sam Cushman; Melanie Murphy; Lisette Waits; Niko Balkenhol

2012-01-01

Different analytical techniques used on the same data set may lead to different conclusions about the existence and strength of genetic structure. Therefore, reliable interpretation of the results from different methods depends on the efficacy and reliability of different statistical methods. In this paper, we evaluated the performance of multiple analytical methods to...

RADC thermal guide for reliability engineers

NASA Astrophysics Data System (ADS)

Morrison, G. N.; Kallis, J. M.; Strattan, L. A.; Jones, I. R.; Lena, A. L.

1982-06-01

This guide was developed to provide a reliability engineer, who is not proficient in thermal design and analysis techniques, with the tools for managing and evaluating the thermal design and production of electronic equipment. It defines the requirements and tasks that should be addressed in system equipment specifications and statements of work, and describes how to evaluate performance.

Evaluating growth performance of young stands

Treesearch

A. L. Roe; R. E. Benson

1966-01-01

A simple procedure for evaluating the diameter growth of young stands in relation to potential growth is described. A comparison technique is developed which contrasts relative diameter of crop trees to the relative diameter growth of the last decade to show the condition and trend of growth in the stand. The method is objective, easy to use, and has several...

Development and evaluation of an off-the-slide genotyping technique for identifying Giardia cysts and Cryptosporidium oocysts directly from US EPA Method 1623 slides

EPA Science Inventory

ABSTRACT Aims This study developed and systematically evaluated performance and limit of detection of an off-the-slide genotyping procedure for both Cryptosporidium oocysts and Giardia cysts. Methods and Results Slide standards containing flow sorted (oo)cysts were used to e...

MALDI-TOF for the rapid detection of carbapenemase-producing Enterobacteriaceae: comparison of the commercialized MBT STAR®-Carba IVD Kit with two in-house MALDI-TOF techniques and the RAPIDEC® CARBA NP.

PubMed

Dortet, Laurent; Tandé, Didier; de Briel, Dominique; Bernabeu, Sandrine; Lasserre, Camille; Gregorowicz, Guillaume; Jousset, Agnès B; Naas, Thierry

2018-06-11

There is an urgent need for accurate and fast diagnostic tests to identify carbapenemase-producing bacteria. Here, we have evaluated three MALDI-TOF-based techniques to detect carbapenemase-producing Enterobacteriaceae (CPE) from cultured colonies. The performance of three MALDI-TOF-based techniques, including the commercialized MBT STAR®-Carba IVD Kit (Bruker Daltonics) and two in-house protocols performed on the Microflex LT Biotyper (Bruker Daltonics) and the VITEK® MS Plus (bioMérieux), were compared with those of the RAPIDEC® CARBA NP (bioMérieux). A collection of 175 isolates including 120 carbapenemase producers and 55 non-carbapenemase producers was tested. Samples were tested blind in the three participating centres. The repeatability of the MBT STAR®-Carba IVD Kit was also evaluated. The three MALDI-TOF techniques possess sensitivities ranging from 95% to 100% and specificities from 98.2% to 100% compared with 99.2% and 100%, respectively, for the RAPIDEC® CARBA NP. The MBT STAR®-Carba IVD Kit gave highly reproducible results and is the only technique able to provide a concomitant identification of the bacterial isolate. The three MALDI-TOF techniques possess a fast turnaround time (less than 1.5 h). Overall, MALDI-TOF is a reliable technique for the rapid detection of CPE from cultured colonies. MBT STAR®-Carba IVD Kit, the only commercially available assay, could easily be implemented in a clinical microbiology laboratory if it is already equipped with a Microflex LT Biotyper mass spectrometer.

Retention of fissure sealants in young permanent molars affected by dental fluorosis: a 12-month clinical study.

PubMed

Hasanuddin, S; Reddy, E R; Manjula, M; Srilaxmi, N; Rani, S T; Rajesh, A

2014-10-01

To evaluate and compare retention and caries occurance following placement of Clinpro and FUJI VII fissure sealants, by two different techniques simultaneously in unsealed, contralateral young permanent molars of 7- to 10-year-old children affected by mild to moderate dental fluorosis at various recall intervals of 1 week, 1, 3, 6 and 12 months. 80 schoolchildren with mild to moderate dental fluorosis were assigned to Group A and Group B with 40 children in each group. In Group A Clinpro fissure sealant and in Group B Fuji VII fissure sealant was used. In both the groups fissure sealants were applied by conventional fissure sealant technique (CST) on one side and enameloplasty sealant technique (EST) on the other side of the same arch. The applied fissure sealants were evaluated clinically for retention and caries incidence. Clinpro fissure sealant showed a retention rate of 95% when compared with Fuji VII (57.5%) at the end of 12 months, which was statistically significant. Regarding techniques, EST showed better results than CST in both the groups. Comparison of groups with respect to retention and techniques at different time periods was performed using Mann-Whitney U test (p < 0.05). Comparison of different time periods with respect to retention and technique in all the groups was performed using Wilcoxon matched pairs test by ranks (p < 0.05). Clinpro fissure sealant showed better retention at all treatment intervals, when compared with Fuji VII. Further follow-up is required to study the efficacy of the fissure sealant placement techniques.

Employing lighting techniques during on-orbit operations

NASA Technical Reports Server (NTRS)

Wheelwright, Charles D.; Toole, Jennifer R.

1991-01-01

As a result of past space missions and evaluations, many procedures have been established and shown to be prudent applications for use in present and future space environment scenarios. However, recent procedures to employ the use of robotics to assist crewmembers in performing tasks which require viewing remote and obstructed locations have led to a need to pursue alternative methods to assist in these operations. One of those techniques which is under development entails incorporating the use of suitable lighting aids/techniques with a closed circuit television (CCTV) camera/monitor system to supervise the robotics operations. The capability to provide adequate lighting during grappling, deploying, docking and berthing operations under all on-orbit illumination conditions is essential to a successful mission. Using automated devices such as the Remote Manipulator System (RMS) to dock and berth a vehicle during payload retrieval, under nighttime, earthshine, solar, or artificial illumination conditions can become a cumbersome task without first incorporating lighting techniques that provide the proper target illumination, orientation, and alignment cues. Studies indicate that the use of visual aids such as the CCTV with a pretested and properly oriented lighting system can decrease the time necessary to accomplish grappling tasks. Evaluations have been and continue to be performed to assess the various on-orbit conditions in order to predict and determine the appropriate lighting techniques and viewing angles necessary to assist crewmembers in payload operations.

Employing lighting techniques during on-orbit operations

NASA Astrophysics Data System (ADS)

Wheelwright, Charles D.; Toole, Jennifer R.

As a result of past space missions and evaluations, many procedures have been established and shown to be prudent applications for use in present and future space environment scenarios. However, recent procedures to employ the use of robotics to assist crewmembers in performing tasks which require viewing remote and obstructed locations have led to a need to pursue alternative methods to assist in these operations. One of those techniques which is under development entails incorporating the use of suitable lighting aids/techniques with a closed circuit television (CCTV) camera/monitor system to supervise the robotics operations. The capability to provide adequate lighting during grappling, deploying, docking and berthing operations under all on-orbit illumination conditions is essential to a successful mission. Using automated devices such as the Remote Manipulator System (RMS) to dock and berth a vehicle during payload retrieval, under nighttime, earthshine, solar, or artificial illumination conditions can become a cumbersome task without first incorporating lighting techniques that provide the proper target illumination, orientation, and alignment cues. Studies indicate that the use of visual aids such as the CCTV with a pretested and properly oriented lighting system can decrease the time necessary to accomplish grappling tasks. Evaluations have been and continue to be performed to assess the various on-orbit conditions in order to predict and determine the appropriate lighting techniques and viewing angles necessary to assist crewmembers in payload operations.

An In vitro Comparison and Evaluation of Sealing Ability of Newly Introduced C-point System, Cold Lateral Condensation, and Thermoplasticized Gutta-Percha Obturating Technique: A Dye Extraction Study.

PubMed

Sinhal, Tapati Manohar; Shah, Ruchi Rani Purvesh; Jais, Pratik Subhas; Shah, Nimisha Chinmay; Hadwani, Krupali Dhirubhai; Rothe, Tushar; Sinhal, Neha Nilesh

2018-01-01

The aim of this study is to compare and to evaluate sealing ability of newly introduced C-point system, cold lateral condensation, and thermoplasticized gutta-percha obturating technique using a dye extraction method. Sixty extracted maxillary central incisors were decoronated below the cementoenamel junction. Working length was established, and biomechanical preparation was done using K3 rotary files with standard irrigation protocol. Teeth were divided into three groups according to the obturation protocol; Group I-Cold lateral condensation, Group II-Thermoplasticized gutta-percha, and Group III-C-Point obturating system. After obturation all samples were subjected to microleakage assessment using dye extraction method. Obtained scores will be statistical analyzed using ANOVA test and post hoc Tukey's test. One-way analysis of variance revealed that there is significant difference among the three groups with P value (0.000 < 0.05). Tukey's HSD post hoc tests for multiple comparisons test shows that the Group II and III perform significantly better than Group I. Group III performs better than Group II with no significant difference. All the obturating technique showed some degree of microleakage. Root canals filled with C-point system showed least microleakage followed by thermoplasticized obturating technique with no significant difference among them. C-point obturation system could be an alternative to the cold lateral condensation technique.

Evaluation of bone marrow specimens with acute myelogenous leukemia for CD34, CD15, CD117, and myeloperoxidase.

PubMed

Dunphy, C H; Polski, J M; Evans, H L; Gardner, L J

2001-08-01

Immunophenotyping of bone marrow (BM) specimens with acute myelogenous leukemia (AML) may be performed by flow cytometric (FC) or immunohistochemical (IH) techniques. Some markers (CD34, CD15, and CD117) are available for both techniques. Myeloperoxidase (MPO) analysis may be performed by enzyme cytochemical (EC) or IH techniques. To determine the reliability of these markers and MPO by these techniques, we designed a study to compare the results of analyses of these markers and MPO by FC (CD34, CD15, and CD117), EC (MPO), and IH (CD34, CD15, CD117, and MPO) techniques. Twenty-nine AMLs formed the basis of the study. These AMLs all had been immunophenotyped previously by FC analysis; 27 also had had EC analysis performed. Of the AMLs, 29 had BM core biopsies and 26 had BM clots that could be evaluated. The paraffin blocks of the 29 BM core biopsies and 26 BM clots were stained for CD34, CD117, MPO, and CD15. These results were compared with results by FC analysis (CD34, CD15, and CD117) and EC analysis (MPO). Immunodetection of CD34 expression in AML had a similar sensitivity by FC and IH techniques. Immunodetection of CD15 and CD117 had a higher sensitivity by FC analysis than by IH analysis. Detection of MPO by IH analysis was more sensitive than by EC analysis. There was no correlation of French-American-British (FAB) subtype of AML with CD34 or CD117 expression. Expression of CD15 was associated with AMLs with a monocytic component. Myeloperoxidase reactivity by IH analysis was observed in AMLs originally FAB subtyped as M0. CD34 can be equally detected by FC and IH techniques. CD15 and CD117 are better detected by FC analysis and MPO is better detected by IH analysis.

An overlooked complication of the inguinal hernia repair: Dysejaculation

PubMed Central

Yılmaz, Hüseyin

2018-01-01

The objective of this study was to investigate the rate of post-herniorrhaphy dysejaculation in the current literature. A comprehensive search of PubMed, Medline, Google Scholar, and Google databases was performed using the keywords “groin hernia and chronic pain,” “inguinal hernia and chronic pain,” “dysejaculation,” and “ejaculatory pain.” The eligible studies were evaluated in terms of ejaculatory pain and surgical technique used. Ten studies with 122 patients were eligible for the analysis. The rate of ejaculatory pain for a total of 5521 patients was found to be 2.2%. The incidence of postoperative ejaculatory pain was found to be 2.1% following laparoscopic techniques and 1.1 % following open repair. Open techniques were not related to the increased frequency of dysejaculation. Sufficient data could not be obtained from the studies for the ejaculatory pain, and thus, no statistical evaluation was performed. Dysejaculation is a common cause of postoperative morbidity after inguinal hernia repair. Attention to technical details of the primary operation may reduce the incidence of dysejaculation. PMID:29756096

Transaxillary Robotic Thyroid Surgery: A Preliminary European Experience

PubMed Central

Lallemant, Benjamin; Chambon, Guillaume; Galy-Bernadoy, Camille; Chapuis, Héliette; Guedj, Anne-Marie; Pham, Huy Trang; Lallemant, Jean-Gabriel; Rupp, Damien

2013-01-01

Background Robot-assisted endoscopic transaxillary thyroidectomy is an emerging surgical technique that needs to be evaluated in European patients. We evaluate the feasibility and preliminary results of our experience of this technique in a cohort of patients from within a single European university hospital (Nîmes, France). Methods We performed a retrospective review of the first 23 patients, treated consecutively between September 2010 and June 2012. Results Nine patients underwent total thyroidectomy and 14 patients lobectomies. All procedures were completed successfully with a mean total operative time of 134 min. We observed a single case of internal jugular vein injury during the console time. No instances of persistent complications were observed; however, minor postoperative events occurred in 5 patients. Pathological diagnoses included benign follicular adenoma in 18 patients, benign adenoma with lymphoid thyroiditis in 1 patient, and benign adenoma with Graves' disease in 4 patients. Conclusions Robotic thyroid surgery is feasible in European patients and can be safely performed on selected patients. This technique has infrequent minor complications and provides a high level of satisfaction. PMID:24783048

Advanced Recording and Preprocessing of Physiological Signals. [data processing equipment for flow measurement of blood flow by ultrasonics

NASA Technical Reports Server (NTRS)

Bentley, P. B.

1975-01-01

The measurement of the volume flow-rate of blood in an artery or vein requires both an estimate of the flow velocity and its spatial distribution and the corresponding cross-sectional area. Transcutaneous measurements of these parameters can be performed using ultrasonic techniques that are analogous to the measurement of moving objects by use of a radar. Modern digital data recording and preprocessing methods were applied to the measurement of blood-flow velocity by means of the CW Doppler ultrasonic technique. Only the average flow velocity was measured and no distribution or size information was obtained. Evaluations of current flowmeter design and performance, ultrasonic transducer fabrication methods, and other related items are given. The main thrust was the development of effective data-handling and processing methods by application of modern digital techniques. The evaluation resulted in useful improvements in both the flowmeter instrumentation and the ultrasonic transducers. Effective digital processing algorithms that provided enhanced blood-flow measurement accuracy and sensitivity were developed. Block diagrams illustrative of the equipment setup are included.

Human Actions Analysis: Templates Generation, Matching and Visualization Applied to Motion Capture of Highly-Skilled Karate Athletes

PubMed Central

Piekarczyk, Marcin; Ogiela, Marek R.

2017-01-01

The aim of this paper is to propose and evaluate the novel method of template generation, matching, comparing and visualization applied to motion capture (kinematic) analysis. To evaluate our approach, we have used motion capture recordings (MoCap) of two highly-skilled black belt karate athletes consisting of 560 recordings of various karate techniques acquired with wearable sensors. We have evaluated the quality of generated templates; we have validated the matching algorithm that calculates similarities and differences between various MoCap data; and we have examined visualizations of important differences and similarities between MoCap data. We have concluded that our algorithms works the best when we are dealing with relatively short (2–4 s) actions that might be averaged and aligned with the dynamic time warping framework. In practice, the methodology is designed to optimize the performance of some full body techniques performed in various sport disciplines, for example combat sports and martial arts. We can also use this approach to generate templates or to compare the correct performance of techniques between various top sportsmen in order to generate a knowledge base of reference MoCap videos. The motion template generated by our method can be used for action recognition purposes. We have used the DTW classifier with angle-based features to classify various karate kicks. We have performed leave-one-out action recognition for the Shorin-ryu and Oyama karate master separately. In this case, 100% actions were correctly classified. In another experiment, we used templates generated from Oyama master recordings to classify Shorin-ryu master recordings and vice versa. In this experiment, the overall recognition rate was 94.2%, which is a very good result for this type of complex action. PMID:29125560

Space Suit Performance: Methods for Changing the Quality of Quantitative Data

NASA Technical Reports Server (NTRS)

Cowley, Matthew; Benson, Elizabeth; Rajulu, Sudhakar

2014-01-01

NASA is currently designing a new space suit capable of working in deep space and on Mars. Designing a suit is very difficult and often requires trade-offs between performance, cost, mass, and system complexity. To verify that new suits will enable astronauts to perform to their maximum capacity, prototype suits must be built and tested with human subjects. However, engineers and flight surgeons often have difficulty understanding and applying traditional representations of human data without training. To overcome these challenges, NASA is developing modern simulation and analysis techniques that focus on 3D visualization. Early understanding of actual performance early on in the design cycle is extremely advantageous to increase performance capabilities, reduce the risk of injury, and reduce costs. The primary objective of this project was to test modern simulation and analysis techniques for evaluating the performance of a human operating in extra-vehicular space suits.

Heat pipe investigations

NASA Technical Reports Server (NTRS)

Marshburn, J. P.

1973-01-01

Techniques associated with thermal-vacuum and bench testing, along with flight testing of the OAO-C spacecraft heat pipes are outlined, to show that the processes used in heat transfer design and testing are adequate for good performance evaluations.

Flight selection at United Airlines

NASA Technical Reports Server (NTRS)

Traub, W.

1980-01-01

Airline pilot selection proceedures are discussed including psychogical and personality tests, psychomotor performance requirements, and flight skills evaluation. Necessary attitude and personality traits are described and an outline of computer selection, testing, and training techniques is given.

Deep Space Telecommunications Systems Engineering

NASA Technical Reports Server (NTRS)

Yuen, J. H. (Editor)

1982-01-01

Descriptive and analytical information useful for the optimal design, specification, and performance evaluation of deep space telecommunications systems is presented. Telemetry, tracking, and command systems, receiver design, spacecraft antennas, frequency selection, interference, and modulation techniques are addressed.

Green noise wall construction and evaluation : executive summary report.

DOT National Transportation Integrated Search

2011-09-01

Over the years, considerable research has been : performed towards effective and practical noise : abatement measures. Some of these techniques include : traffic management, use of quieter and noise absorbing : pavement surfaces, improving land use a...

Baffling or Baffled: Improve Your Acoustics.

ERIC Educational Resources Information Center

Abdoo, Frank B.

1981-01-01

Presents techniques for evaluating the acoustics (reverberation time, and standing waves and resonance phenomena) of a band performance room. Gives instructions for building and placing inexpensive baffles (free-standing, portable sound barriers) to correct room defects. (SJL)

Performance Evaluation and Modeling Techniques for Parallel Processors. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Dimpsey, Robert Tod

1992-01-01

In practice, the performance evaluation of supercomputers is still substantially driven by singlepoint estimates of metrics (e.g., MFLOPS) obtained by running characteristic benchmarks or workloads. With the rapid increase in the use of time-shared multiprogramming in these systems, such measurements are clearly inadequate. This is because multiprogramming and system overhead, as well as other degradations in performance due to time varying characteristics of workloads, are not taken into account. In multiprogrammed environments, multiple jobs and users can dramatically increase the amount of system overhead and degrade the performance of the machine. Performance techniques, such as benchmarking, which characterize performance on a dedicated machine ignore this major component of true computer performance. Due to the complexity of analysis, there has been little work done in analyzing, modeling, and predicting the performance of applications in multiprogrammed environments. This is especially true for parallel processors, where the costs and benefits of multi-user workloads are exacerbated. While some may claim that the issue of multiprogramming is not a viable one in the supercomputer market, experience shows otherwise. Even in recent massively parallel machines, multiprogramming is a key component. It has even been claimed that a partial cause of the demise of the CM2 was the fact that it did not efficiently support time-sharing. In the same paper, Gordon Bell postulates that, multicomputers will evolve to multiprocessors in order to support efficient multiprogramming. Therefore, it is clear that parallel processors of the future will be required to offer the user a time-shared environment with reasonable response times for the applications. In this type of environment, the most important performance metric is the completion of response time of a given application. However, there are a few evaluation efforts addressing this issue.

Performance Evaluation of EnKF-based Hydrogeological Site Characterization using Color Coherent Vectors

NASA Astrophysics Data System (ADS)

Moslehi, M.; de Barros, F.

2017-12-01

Complexity of hydrogeological systems arises from the multi-scale heterogeneity and insufficient measurements of their underlying parameters such as hydraulic conductivity and porosity. An inadequate characterization of hydrogeological properties can significantly decrease the trustworthiness of numerical models that predict groundwater flow and solute transport. Therefore, a variety of data assimilation methods have been proposed in order to estimate hydrogeological parameters from spatially scarce data by incorporating the governing physical models. In this work, we propose a novel framework for evaluating the performance of these estimation methods. We focus on the Ensemble Kalman Filter (EnKF) approach that is a widely used data assimilation technique. It reconciles multiple sources of measurements to sequentially estimate model parameters such as the hydraulic conductivity. Several methods have been used in the literature to quantify the accuracy of the estimations obtained by EnKF, including Rank Histograms, RMSE and Ensemble Spread. However, these commonly used methods do not regard the spatial information and variability of geological formations. This can cause hydraulic conductivity fields with very different spatial structures to have similar histograms or RMSE. We propose a vision-based approach that can quantify the accuracy of estimations by considering the spatial structure embedded in the estimated fields. Our new approach consists of adapting a new metric, Color Coherent Vectors (CCV), to evaluate the accuracy of estimated fields achieved by EnKF. CCV is a histogram-based technique for comparing images that incorporate spatial information. We represent estimated fields as digital three-channel images and use CCV to compare and quantify the accuracy of estimations. The sensitivity of CCV to spatial information makes it a suitable metric for assessing the performance of spatial data assimilation techniques. Under various factors of data assimilation methods such as number, layout, and type of measurements, we compare the performance of CCV with other metrics such as RMSE. By simulating hydrogeological processes using estimated and true fields, we observe that CCV outperforms other existing evaluation metrics.

Nurses' knowledge of inhaler technique in the inpatient hospital setting.

PubMed

De Tratto, Katie; Gomez, Christy; Ryan, Catherine J; Bracken, Nina; Steffen, Alana; Corbridge, Susan J

2014-01-01

High rates of inhaler misuse in patients with chronic obstructive pulmonary disease and asthma contribute to hospital readmissions and increased healthcare cost. The purpose of this study was to examine inpatient staff nurses' self-perception of their knowledge of proper inhaler technique compared with demonstrated technique and frequency of providing patients with inhaler technique teaching during hospitalization and at discharge. A prospective, descriptive study. A 495-bed urban academic medical center in the Midwest United States. A convenience sample of 100 nurses working on inpatient medical units. Participants completed a 5-item, 4-point Likert-scale survey evaluating self-perception of inhaler technique knowledge, frequency of providing patient education, and responsibility for providing education. Participants demonstrated inhaler technique to the investigators using both a metered dose inhaler (MDI) and Diskus device inhaler, and performance was measured via a validated checklist. Overall misuse rates were high for both MDI and Diskus devices. There was poor correlation between perceived ability and investigator-measured performance of inhaler technique. Frequency of education during hospitalization and at discharge was related to measured level of performance for the Diskus device but not for the MDI. Nurses are a key component of patient education in the hospital; however, nursing staff lack adequate knowledge of inhaler technique. Identifying gaps in nursing knowledge regarding proper inhaler technique and patient education about proper inhaler technique is important to design interventions that may positively impact patient outcomes. Interventions could include one-on-one education, Web-based education, unit-based education, or hospital-wide competency-based education. All should include return demonstration of appropriate technique.

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.

NetCoDer: A Retransmission Mechanism for WSNs Based on Cooperative Relays and Network Coding

PubMed Central

Valle, Odilson T.; Montez, Carlos; Medeiros de Araujo, Gustavo; Vasques, Francisco; Moraes, Ricardo

2016-01-01

Some of the most difficult problems to deal with when using Wireless Sensor Networks (WSNs) are related to the unreliable nature of communication channels. In this context, the use of cooperative diversity techniques and the application of network coding concepts may be promising solutions to improve the communication reliability. In this paper, we propose the NetCoDer scheme to address this problem. Its design is based on merging cooperative diversity techniques and network coding concepts. We evaluate the effectiveness of the NetCoDer scheme through both an experimental setup with real WSN nodes and a simulation assessment, comparing NetCoDer performance against state-of-the-art TDMA-based (Time Division Multiple Access) retransmission techniques: BlockACK, Master/Slave and Redundant TDMA. The obtained results highlight that the proposed NetCoDer scheme clearly improves the network performance when compared with other retransmission techniques. PMID:27258280

Anomaly Detection Techniques with Real Test Data from a Spinning Turbine Engine-Like Rotor

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Woike, Mark R.; Oza, Nikunj C.; Matthews, Bryan L.

2012-01-01

Online detection techniques to monitor the health of rotating engine components are becoming increasingly attractive to aircraft engine manufacturers in order to increase safety of operation and lower maintenance costs. Health monitoring remains a challenge to easily implement, especially in the presence of scattered loading conditions, crack size, component geometry, and materials properties. The current trend, however, is to utilize noninvasive types of health monitoring or nondestructive techniques to detect hidden flaws and mini-cracks before any catastrophic event occurs. These techniques go further to evaluate material discontinuities and other anomalies that have grown to the level of critical defects that can lead to failure. Generally, health monitoring is highly dependent on sensor systems capable of performing in various engine environmental conditions and able to transmit a signal upon a predetermined crack length, while acting in a neutral form upon the overall performance of the engine system.

Optimizing Instruction Scheduling and Register Allocation for Register-File-Connected Clustered VLIW Architectures

PubMed Central

Tang, Haijing; Wang, Siye; Zhang, Yanjun

2013-01-01

Clustering has become a common trend in very long instruction words (VLIW) architecture to solve the problem of area, energy consumption, and design complexity. Register-file-connected clustered (RFCC) VLIW architecture uses the mechanism of global register file to accomplish the inter-cluster data communications, thus eliminating the performance and energy consumption penalty caused by explicit inter-cluster data move operations in traditional bus-connected clustered (BCC) VLIW architecture. However, the limit number of access ports to the global register file has become an issue which must be well addressed; otherwise the performance and energy consumption would be harmed. In this paper, we presented compiler optimization techniques for an RFCC VLIW architecture called Lily, which is designed for encryption systems. These techniques aim at optimizing performance and energy consumption for Lily architecture, through appropriate manipulation of the code generation process to maintain a better management of the accesses to the global register file. All the techniques have been implemented and evaluated. The result shows that our techniques can significantly reduce the penalty of performance and energy consumption due to access port limitation of global register file. PMID:23970841

Status of Thermal NDT of Space Shuttle Materials at NASA

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Winfree, William P.; Hodges, Kenneth; Koshti, Ajay; Ryan, Daniel; Reinhardt, Walter W.

2006-01-01

Since the Space Shuttle Columbia accident, NASA has focused on improving advanced nondestructive evaluation (NDE) techniques for the Reinforced Carbon-Carbon (RCC) panels that comprise the orbiter's wing leading edge and nose cap. Various nondestructive inspection techniques have been used in the examination of the RCC, but thermography has emerged as an effective inspection alternative to more traditional methods. Thermography is a non-contact inspection method as compared to ultrasonic techniques which typically require the use of a coupling medium between the transducer and material. Like radiographic techniques, thermography can inspect large areas, but has the advantage of minimal safety concerns and the ability for single-sided measurements. Details of the analysis technique that has been developed to allow insitu inspection of a majority of shuttle RCC components is discussed. Additionally, validation testing, performed to quantify the performance of the system, will be discussed. Finally, the results of applying this technology to the Space Shuttle Discovery after its return from the STS-114 mission in July 2005 are discussed.

Evaluation of the Accuracy of Conventional and Digital Impression Techniques for Implant Restorations.

PubMed

Moura, Renata Vasconcellos; Kojima, Alberto Noriyuki; Saraceni, Cintia Helena Coury; Bassolli, Lucas; Balducci, Ivan; Özcan, Mutlu; Mesquita, Alfredo Mikail Melo

2018-05-01

The increased use of CAD systems can generate doubt about the accuracy of digital impressions for angulated implants. The aim of this study was to evaluate the accuracy of different impression techniques, two conventional and one digital, for implants with and without angulation. We used a polyurethane cast that simulates the human maxilla according to ASTM F1839, and 6 tapered implants were installed with external hexagonal connections to simulate tooth positions 17, 15, 12, 23, 25, and 27. Implants 17 and 23 were placed with 15° of mesial angulation and distal angulation, respectively. Mini cone abutments were installed on these implants with a metal strap 1 mm in height. Conventional and digital impression procedures were performed on the maxillary master cast, and the implants were separated into 6 groups based on the technique used and measurement type: G1 - control, G2 - digital impression, G3 - conventional impression with an open tray, G4 - conventional impression with a closed tray, G5 - conventional impression with an open tray and a digital impression, and G6 - conventional impression with a closed tray and a digital impression. A statistical analysis was performed using two-way repeated measures ANOVA to compare the groups, and a Kruskal-Wallis test was conducted to analyze the accuracy of the techniques. No significant difference in the accuracy of the techniques was observed between the groups. Therefore, no differences were found among the conventional impression and the combination of conventional and digital impressions, and the angulation of the implants did not affect the accuracy of the techniques. All of the techniques exhibited trueness and had acceptable precision. The variation of the angle of the implants did not affect the accuracy of the techniques. © 2018 by the American College of Prosthodontists.

Evaluation of Clipping Based Iterative PAPR Reduction Techniques for FBMC Systems

PubMed Central

Kollár, Zsolt

2014-01-01

This paper investigates filter bankmulticarrier (FBMC), a multicarrier modulation technique exhibiting an extremely low adjacent channel leakage ratio (ACLR) compared to conventional orthogonal frequency division multiplexing (OFDM) technique. The low ACLR of the transmitted FBMC signal makes it especially favorable in cognitive radio applications, where strict requirements are posed on out-of-band radiation. Large dynamic range resulting in high peak-to-average power ratio (PAPR) is characteristic of all sorts of multicarrier signals. The advantageous spectral properties of the high-PAPR FBMC signal are significantly degraded if nonlinearities are present in the transceiver chain. Spectral regrowth may appear, causing harmful interference in the neighboring frequency bands. This paper presents novel clipping based PAPR reduction techniques, evaluated and compared by simulations and measurements, with an emphasis on spectral aspects. The paper gives an overall comparison of PAPR reduction techniques, focusing on the reduction of the dynamic range of FBMC signals without increasing out-of-band radiation. An overview is presented on transmitter oriented techniques employing baseband clipping, which can maintain the system performance with a desired bit error rate (BER). PMID:24558338

A Learning Evaluation for an Immersive Virtual Laboratory for Technical Training Applied into a Welding Workshop

ERIC Educational Resources Information Center

Torres, Francisco; Neira Tovar, Leticia A.; del Rio, Marta Sylvia

2017-01-01

This study aims to explore the results of welding virtual training performance, designed using a learning model based on cognitive and usability techniques, applying an immersive concept focused on person attention. Moreover, it also intended to demonstrate that exits a moderating effect of performance improvement when the user experience is taken…

Embedded Electro-Optic Sensor Network for the On-Site Calibration and Real-Time Performance Monitoring of Large-Scale Phased Arrays

DTIC Science & Technology

2005-07-09

This final report summarizes the progress during the Phase I SBIR project entitled Embedded Electro - Optic Sensor Network for the On-Site Calibration...network based on an electro - optic field-detection technique (the Electro - optic Sensor Network, or ESN) for the performance evaluation of phased

Piloted-simulation evaluation of escape guidance for microburst wind shear encounters. M.S. Thesis - George Washington Univ.

NASA Technical Reports Server (NTRS)

Hinton, David A.

1989-01-01

Numerous air carrier accidents and incidents result from encounters with the atmospheric wind shear associated with microburst phenomena, in some cases resulting in heavy loss of life. An important issue in current wind shear research is how to best manage aircraft performance during an inadvertent wind shear encounter. The goals of this study were to: (1) develop techniques and guidance for maximizing an aircraft's ability to recover from microburst encounters following takeoff, (2) develop an understanding of how theoretical predictions of wind shear recovery performance might be achieved in actual use, and (3) gain insight into the piloting factors associated with recovery from microburst encounters. Three recovery strategies were implemented and tested in piloted simulation. Results show that a recovery strategy based on flying a flight path angle schedule produces improved performance over constant pitch attitude or acceleration-based recovery techniques. The best recovery technique was initially counterintuitive to the pilots who participated in the study. Evidence was found to indicate that the techniques required for flight through the turbulent vortex of a microburst may differ from the techniques being developed using classical, nonturbulent microburst models.

CPE--A New Perspective: The Impact of the Technology Revolution. Proceedings of the Computer Performance Evaluation Users Group Meeting (19th, San Francisco, California, October 25-28, 1983). Final Report. Reports on Computer Science and Technology.

ERIC Educational Resources Information Center

Mobray, Deborah, Ed.

Papers on local area networks (LANs), modelling techniques, software improvement, capacity planning, software engineering, microcomputers and end user computing, cost accounting and chargeback, configuration and performance management, and benchmarking presented at this conference include: (1) "Theoretical Performance Analysis of Virtual…

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

Evaluating Quality of Decision-Making Processes in Medicines' Development, Regulatory Review, and Health Technology Assessment: A Systematic Review of the Literature.

PubMed

Bujar, Magdalena; McAuslane, Neil; Walker, Stuart R; Salek, Sam

2017-01-01

Introduction: Although pharmaceutical companies, regulatory authorities, and health technology assessment (HTA) agencies have been increasingly using decision-making frameworks, it is not certain whether these enable better quality decision making. This could be addressed by formally evaluating the quality of decision-making process within those organizations. The aim of this literature review was to identify current techniques (tools, questionnaires, surveys, and studies) for measuring the quality of the decision-making process across the three stakeholders. Methods: Using MEDLINE, Web of Knowledge, and other Internet-based search engines, a literature review was performed to systematically identify techniques for assessing quality of decision making in medicines development, regulatory review, and HTA. A structured search was applied using key words and a secondary review was carried out. In addition, the measurement properties of each technique were assessed and compared. Ten Quality Decision-Making Practices (QDMPs) developed previously were then used as a framework for the evaluation of techniques identified in the review. Due to the variation in studies identified, meta-analysis was inappropriate. Results: This review identified 13 techniques, where 7 were developed specifically to assess decision making in medicines' development, regulatory review, or HTA; 2 examined corporate decision making, and 4 general decision making. Regarding how closely each technique conformed to the 10 QDMPs, the 13 techniques assessed a median of 6 QDMPs, with a mode of 3 QDMPs. Only 2 techniques evaluated all 10 QDMPs, namely the Organizational IQ and the Quality of Decision Making Orientation Scheme (QoDoS), of which only one technique, QoDoS could be applied to assess decision making of both individuals and organizations, and it possessed generalizability to capture issues relevant to companies as well as regulatory authorities. Conclusion: This review confirmed a general paucity of research in this area, particularly regarding the development and systematic application of techniques for evaluating quality decision making, with no consensus around a gold standard. This review has identified QoDoS as the most promising available technique for assessing decision making in the lifecycle of medicines and the next steps would be to further test its validity, sensitivity, and reliability.

Experimental evaluation of multiprocessor cache-based error recovery

NASA Technical Reports Server (NTRS)

Janssens, Bob; Fuchs, W. K.

1991-01-01

Several variations of cache-based checkpointing for rollback error recovery in shared-memory multiprocessors have been recently developed. By modifying the cache replacement policy, these techniques use the inherent redundancy in the memory hierarchy to periodically checkpoint the computation state. Three schemes, different in the manner in which they avoid rollback propagation, are evaluated. By simulation with address traces from parallel applications running on an Encore Multimax shared-memory multiprocessor, the performance effect of integrating the recovery schemes in the cache coherence protocol are evaluated. The results indicate that the cache-based schemes can provide checkpointing capability with low performance overhead but uncontrollable high variability in the checkpoint interval.

Bibliography on augmentation of convective heat and mass transfer

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

Bergles, A.E.; Webb, R.L.; Junkhan, G.H.

1979-05-01

Heat transfer augmentation has developed into a major specialty area in heat transfer research and development. A bibliography of world literature on augmentation is presented. The literature is classified into passive augmentation techniques, which require no external power, and active techniques, which do require external power. The fourteen techniques are grouped in terms of their application to the various modes of heat transfer. Mass transfer is included for completeness. Key words are included with each citation for technique/mode identification. The total number of publications cited is 1,967, including 75 surveys of various techniques and 42 papers on performance evaluation ofmore » passive techniques. Patents are not included as they will be the subject of a future topical report.« less

An evaluation of children's metered-dose inhaler technique for asthma medications.

PubMed

Burkhart, Patricia V; Rayens, Mary Kay; Bowman, Roxanne K

2005-03-01

Regardless of the medication delivery system, health care providers need to teach accurate medication administration techniques to their patients, educate them about the particular nuances of the prescribed delivery system (eg, proper storage), and reinforce these issues at each health encounter. A single instruction session is not sufficient to maintain appropriate inhaler techniques for patients who require continued use. Providing written steps for the administration technique is helpful so that the patient can refer to them later when using the medication. The National Heart, Lung, and Blood Institute's "Practical Guide for the Diagnosis and Management of Asthma" recommends that practitioners follow these steps for effective inhaler technique training when first prescribing an inhaler: 1. Teach patients the steps and give written instruction handouts. 2. Demonstrate how to use the inhaler step-by-step. 3. Ask patients to demonstrate how to use the inhaler. Let the patient refer to the handout on the first training. Then use the handout asa checklist to assess the patient's future technique. 4. Provide feedback to patients about what they did right and what they need to improve. Have patients demonstrate their technique again, if necessary. The last two steps should be performed (ie, demonstration and providing feedback on what patients did right and what they need to improve) at every subsequent visit. If the patient makes multiple errors, it is advisable to focus on improving one or two key steps at a time. With improvements in drug delivery come challenges, necessitating that practitioners stay current with new medication administration techniques. Teaching and reinforcing accurate technique at each health care encounter are critical to help ensure medication efficacy for patients with asthma. Since one fifth of children in the study performed incorrect medication technique even after education, checklists of steps for the correct use of inhalation devices, such as those provided in this article, should be given to patients for home use and for use by clinicians to evaluate patient technique at each health encounter.

ESDA®-Lite collection of DNA from latent fingerprints on documents.

PubMed

Plaza, Dane T; Mealy, Jamia L; Lane, J Nicholas; Parsons, M Neal; Bathrick, Abigail S; Slack, Donia P

2015-05-01

The ability to detect and non-destructively collect biological samples for DNA processing would benefit the forensic community by preserving the physical integrity of evidentiary items for more thorough evaluations by other forensic disciplines. The Electrostatic Detection Apparatus (ESDA®) was systemically evaluated for its ability to non-destructively collect DNA from latent fingerprints deposited on various paper substrates for short tandem repeat (STR) DNA profiling. Fingerprints were deposited on a variety of paper substrates that included resume paper, cotton paper, magazine paper, currency, copy paper, and newspaper. Three DNA collection techniques were performed: ESDA collection, dry swabbing, and substrate cutting. Efficacy of each collection technique was evaluated by the quantity of DNA present in each sample and the percent profile generated by each sample. Both the ESDA and dry swabbing non-destructive sampling techniques outperformed the destructive methodology of substrate cutting. A greater number of full profiles were generated from samples collected with the non-destructive dry swabbing collection technique than were generated from samples collected with the ESDA; however, the ESDA also allowed the user to visualize the area of interest while non-destructively collecting the biological material. The ability to visualize the biological material made sampling straightforward and eliminated the need for numerous, random swabbings/cuttings. Based on these results, the evaluated non-destructive ESDA collection technique has great potential for real-world forensic implementation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Evaluation of the clinical usefulness of modulated arc treatment

NASA Astrophysics Data System (ADS)

Lee, Young Kyu; Jang, Hong Seok; Kim, Yeon Sil; Choi, Byung Ock; Kang, Young-Nam; Nam, Sang Hee; Park, Hyeong Wook; Kim, Shin Wook; Shin, Hun Joo; Lee, Jae Choon; Kim, Ji Na; Park, Sung Kwang; Kim, Jin Young

2015-07-01

The purpose of this study is to evaluate the clinical usefulness of modulated arc (mARC) treatment techniques. The mARC treatment plans for non-small-cell lung cancer (NSCLC) patients were made in order to verify the clinical usefulness of mARC. A pre-study was conducted to find the best plan condition for mARC treatment, and the usefulness of the mARC treatment plan was evaluated by comparing it with other Arc treatment plans such as tomotherapy and RapidArc plans. In the case of mARC, the optimal condition for the mARC plan was determined by comparing the dosimetric performance of the mARC plans developed by using various parameters, which included the photon energy (6 MV, 10 MV), the optimization point angle (6°- 10°intervals), and the total number of segments (36 - 59 segments). The best dosimetric performance of mARC was observed at a 10 MV photon energy, a point angle 6 degrees, and 59 segments. The treatment plans for the three different techniques were compared by using the following parameters: the conformity index (CI), homogeneity index (HI), the target coverage, the dose to the OARs, the number of monitor units (MU), the beam on time, and the normal tissue complication probability (NTCP). As a result, the three different treatment techniques showed similar target coverages. The mARC plan had the lowest V20 (volume of lung receiving > 20 Gy) and MU per fraction compared with both the RapidArc and the tomotherapy plans. The mARC plan reduced the beam on time as well. Therefore, the results of this study provide satisfactory evidence that the mARC technique can be considered as a useful clinical technique for radiation treatment.

Performance Evaluation of 14 Neural Network Architectures Used for Predicting Heat Transfer Characteristics of Engine Oils

NASA Astrophysics Data System (ADS)

Al-Ajmi, R. M.; Abou-Ziyan, H. Z.; Mahmoud, M. A.

2012-01-01

This paper reports the results of a comprehensive study that aimed at identifying best neural network architecture and parameters to predict subcooled boiling characteristics of engine oils. A total of 57 different neural networks (NNs) that were derived from 14 different NN architectures were evaluated for four different prediction cases. The NNs were trained on experimental datasets performed on five engine oils of different chemical compositions. The performance of each NN was evaluated using a rigorous statistical analysis as well as careful examination of smoothness of predicted boiling curves. One NN, out of the 57 evaluated, correctly predicted the boiling curves for all cases considered either for individual oils or for all oils taken together. It was found that the pattern selection and weight update techniques strongly affect the performance of the NNs. It was also revealed that the use of descriptive statistical analysis such as R2, mean error, standard deviation, and T and slope tests, is a necessary but not sufficient condition for evaluating NN performance. The performance criteria should also include inspection of the smoothness of the predicted curves either visually or by plotting the slopes of these curves.

Proximal hypospadias: A persistent challenge. Single institution outcome analysis of three surgical techniques over a 10-year period.

PubMed

Pippi Salle, J L; Sayed, S; Salle, A; Bagli, D; Farhat, W; Koyle, M; Lorenzo, A J

2016-02-01

The optimal treatment of proximal hypospadias remains controversial. Several techniques have been described, but the best approach remains unsettled. To evaluate and compare the complication rates of proximal hypospadias with and without ventral curvature (VC), according to three different surgical techniques: tubularized incised plate (TIP) uretroplasty, dorsal inlay graft TIP (DIG), and staged preputial repair (SR). It was hypothesized that SR performs better than TIP and DIG for proximal hypospadias. Single-center, retrospective chart review of all patients with primary proximal hypospadias reconstructed between 2003 and 2013. The DIG was selectively employed in cases with narrow urethral plate (UP) and deficient spongiosum. Extensive urethral plate (UP) mobilization (UPM), dorsal plication (DP) and/or deep transverse incisions of tunica albuginea (DTITA) were selectively performed when attempting to spare transecting the UP. Division of UP and SR was favored in cases with severe VC (>50°), which was often concurrently managed with DTITA if intrinsic curvature was present. For SR, tubularization of the graft was performed 6 months later. A total of 140 patients were included. Tubularized incised plate (TIP), DIG, and SR techniques were performed in 57, 23, and 60 patients, respectively. The TIP and DIG techniques achieved similar success rates, although DIG was performed in cases of narrow and spongiosum-deficient plates. Reoperation rates with TIP and DIG techniques was 52.6% and 52.1% (NS). Urethro-cutaneous fistulas were seen in 31.5% and 13% of TIP and DIG techniques, respectively. Staged repair accomplished better results than both TIP and DIG techniques, despite being performed in the most unfavorable cases (reoperation rate 28%). After technical modifications, the DIG technique achieved similar outcomes of SR. Proximal hypospadias remains challenging, regardless of the technique utilized for its repair. Urethro-cutaneous fistulas were more commonly seen after long TIP repairs. Approximately half of the patients undergoing long TIP and DIG procedures needed re-intervention, although the percentage decreased significantly with late modifications in the DIG group. Recurrence of VC after TIP and DIG techniques seemed to be a significant and under-reported complication. Staged repairs, despite being performed for the most severe cases, resulted in overall better outcomes. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Optical laboratory solution and error model simulation of a linear time-varying finite element equation

NASA Technical Reports Server (NTRS)

Taylor, B. K.; Casasent, D. P.

1989-01-01

The use of simplified error models to accurately simulate and evaluate the performance of an optical linear-algebra processor is described. The optical architecture used to perform banded matrix-vector products is reviewed, along with a linear dynamic finite-element case study. The laboratory hardware and ac-modulation technique used are presented. The individual processor error-source models and their simulator implementation are detailed. Several significant simplifications are introduced to ease the computational requirements and complexity of the simulations. The error models are verified with a laboratory implementation of the processor, and are used to evaluate its potential performance.

Nondestructive evaluation of ceramic and metal matrix composites for NASA's HITEMP and enabling propulsion materials programs

NASA Technical Reports Server (NTRS)

Generazio, Edward R.

1992-01-01

In a preliminary study, ultrasonic, x-ray opaque, and fluorescent dye penetrants techniques were used to evaluate and characterize ceramic and metal matrix composites. Techniques are highlighted for identifying porosity, fiber alignment, fiber uniformity, matrix cracks, fiber fractures, unbonds or disbonds between laminae, and fiber-to-matrix bond variations. The nondestructive evaluations (NDE) were performed during processing and after thermomechanical testing. Specific examples are given for Si3N4/SiC (SCS-6 fiber), FeCrAlY/Al2O3 fibers, Ti-15-3/SiC (SCS-6 fiber) materials, and Si3N4/SiC (SCS-6 fiber) actively cooled panel components. Results of this study indicate that the choice of the NDE tools to be used can be optimized to yield a faithful and accurate evaluation of advanced composites.

Material characterization and modeling with shear ography

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Callahan, Virginia

1993-01-01

Shearography has emerged as a useful technique for nondestructible evaluation and materials characterization of aerospace materials. A suitable candidate for the technique is to determine the response of debonds on foam-metal interfaces such as the TPS system on the External Tank. The main thrust is to develop a model which allows valid interpretation of shearographic information on TPS type systems. Confirmation of the model with shearographic data will be performed.

A Uniform Profit Policy for Government Acquisition

DTIC Science & Technology

1978-12-01

primarily to evaluate managerial (not economic) performance. The second survey by Gitman and Forrester concentrated on determining the 3 capital...budgeting techniques used by major firms. A list of 268 companies 3 L. J. Gitman , and J. R. Forrester, Jr. , "A Survey of Capital Budgeting Techniques...Approximately 70 percent of the firms responding to the Gitman and Forrester survey required returns of at least 15 percent before considering a project

Digital enhancement of computerized axial tomograms

NASA Technical Reports Server (NTRS)

Roberts, E., Jr.

1978-01-01

A systematic evaluation has been conducted of certain digital image enhancement techniques performed in image space. Three types of images have been used, computer generated phantoms, tomograms of a synthetic phantom, and axial tomograms of human anatomy containing images of lesions, artificially introduced into the tomograms. Several types of smoothing, sharpening, and histogram modification have been explored. It has been concluded that the most useful enhancement techniques are a selective smoothing of singular picture elements, combined with contrast manipulation. The most useful tool in applying these techniques is the gray-scale histogram.

Analytical techniques for mechanistic characterization of EUV photoresists

NASA Astrophysics Data System (ADS)

Grzeskowiak, Steven; Narasimhan, Amrit; Murphy, Michael; Ackerman, Christian; Kaminsky, Jake; Brainard, Robert L.; Denbeaux, Greg

2017-03-01

Extreme ultraviolet (EUV, 13.5 nm) lithography is the prospective technology for high volume manufacturing by the microelectronics industry. Significant strides towards achieving adequate EUV source power and availability have been made recently, but a limited rate of improvement in photoresist performance still delays the implementation of EUV. Many fundamental questions remain to be answered about the exposure mechanisms of even the relatively well understood chemically amplified EUV photoresists. Moreover, several groups around the world are developing revolutionary metal-based resists whose EUV exposure mechanisms are even less understood. Here, we describe several evaluation techniques to help elucidate mechanistic details of EUV exposure mechanisms of chemically amplified and metal-based resists. EUV absorption coefficients are determined experimentally by measuring the transmission through a resist coated on a silicon nitride membrane. Photochemistry can be evaluated by monitoring small outgassing reaction products to provide insight into photoacid generator or metal-based resist reactivity. Spectroscopic techniques such as thin-film Fourier transform infrared (FTIR) spectroscopy can measure the chemical state of a photoresist system pre- and post-EUV exposure. Additionally, electrolysis can be used to study the interaction between photoresist components and low energy electrons. Collectively, these techniques improve our current understanding of photomechanisms for several EUV photoresist systems, which is needed to develop new, better performing materials needed for high volume manufacturing.

Portal vein territory identification using indocyanine green fluorescence imaging: Technical details and short-term outcomes.

PubMed

Kobayashi, Yuta; Kawaguchi, Yoshikuni; Kobayashi, Kosuke; Mori, Kazuhiro; Arita, Junichi; Sakamoto, Yoshihiro; Hasegawa, Kiyoshi; Kokudo, Norihiro

2017-12-01

Portal vein (PV) territory identification during liver resection may be performed using indocyanine green (ICG) fluorescence imaging technique. However, the technical details of the fluorescence staining technique have not been fully elucidated. This study was performed to demonstrate the technical details of PV territory identification using fluorescence imaging and evaluates the short-term outcomes. From 2011 to 2015, 105 underwent liver resection at the University of Tokyo Hospital with one of the following fluorescence staining techniques by transhepatic PV injection or intravenous injection of ICG: single staining (n = 36), multiple staining (n = 31), counterstaining (n = 22), negative staining (n = 13), or paradoxical negative staining (n = 3). The PV territory was identified as a region with fluorescence or a defect of fluorescence using one of the five staining techniques. ICG was administered by transhepatic PV injection in all but the negative staining technique, which employed intravenous injection. No adverse events associated with the ICG administration occurred. The mortality, postoperative total morbidity, and the major complication (Clavien-Dindo grade ≥III) rates were 0.0%, 14.3%, and 7.6%. We have demonstrated the technical details of five types of fluorescence staining techniques. These techniques are safe to perform and facilitate clear visualization of the PV territory in real time, enhancing the efficacy of anatomical removal of such territories. © 2017 Wiley Periodicals, Inc.

Performing the Parryscope technique gently for office tubal patency assessment.

PubMed

Parry, J Preston; Riche, Daniel; Rushing, John; Linton, Brittany; Butler, Vicki; Lindheim, Steven R

2017-10-01

To demonstrate a novel approach to office tubal patency assessment through infusing air into saline during flexible office hysteroscopy. We also provide data addressing pain and patient experience relative to hysterosalpingography (HSG). Video presentation of clinical technique with supportive crossover data (Canadian Task Force classification II-1). Its University of Mississippi Medical Center Institutional Review Board protocol number is 2013-0230. Academic hospital. Women undergoing office hysteroscopy and ultrasound, with a subset also having HSG. Air infusion into saline during office hysteroscopy. The focus is on demonstrating how the technique appears and is performed, with supplemental Likert data addressing subjective pain and preference relative to HSG. When performed as described, this office technique has 98.3%-100% sensitivity to tubal occlusion and 83.7% specificity. The gentle technique is central to accurate outcomes, which is facilitated through use of a small-caliber (<3 mm), flexible hysteroscope and avoiding uterine overdistention. Patients are far more likely to report maximum discomfort with HSG. Among patients who also had HSG, 92% somewhat or strongly prefer hysteroscopic assessment. Also, 96% of patients reporting maximum discomfort with HSG had mild to no discomfort with the described technique. Air-infused saline at flexible office hysteroscopy can accurately, gently, and rapidly assess tubal patency. Coupled with strong patient preference for this technique over HSG, it is a promising option for evaluating fertility. NCT02005263. Published by Elsevier Inc.

Bearing Fault Diagnosis by a Robust Higher-Order Super-Twisting Sliding Mode Observer

PubMed Central

Kim, Jong-Myon

2018-01-01

An effective bearing fault detection and diagnosis (FDD) model is important for ensuring the normal and safe operation of machines. This paper presents a reliable model-reference observer technique for FDD based on modeling of a bearing’s vibration data by analyzing the dynamic properties of the bearing and a higher-order super-twisting sliding mode observation (HOSTSMO) technique for making diagnostic decisions using these data models. The HOSTSMO technique can adaptively improve the performance of estimating nonlinear failures in rolling element bearings (REBs) over a linear approach by modeling 5 degrees of freedom under normal and faulty conditions. The effectiveness of the proposed technique is evaluated using a vibration dataset provided by Case Western Reserve University, which consists of vibration acceleration signals recorded for REBs with inner, outer, ball, and no faults, i.e., normal. Experimental results indicate that the proposed technique outperforms the ARX-Laguerre proportional integral observation (ALPIO) technique, yielding 18.82%, 16.825%, and 17.44% performance improvements for three levels of crack severity of 0.007, 0.014, and 0.021 inches, respectively. PMID:29642459

Bearing Fault Diagnosis by a Robust Higher-Order Super-Twisting Sliding Mode Observer.

PubMed

Piltan, Farzin; Kim, Jong-Myon

2018-04-07

An effective bearing fault detection and diagnosis (FDD) model is important for ensuring the normal and safe operation of machines. This paper presents a reliable model-reference observer technique for FDD based on modeling of a bearing's vibration data by analyzing the dynamic properties of the bearing and a higher-order super-twisting sliding mode observation (HOSTSMO) technique for making diagnostic decisions using these data models. The HOSTSMO technique can adaptively improve the performance of estimating nonlinear failures in rolling element bearings (REBs) over a linear approach by modeling 5 degrees of freedom under normal and faulty conditions. The effectiveness of the proposed technique is evaluated using a vibration dataset provided by Case Western Reserve University, which consists of vibration acceleration signals recorded for REBs with inner, outer, ball, and no faults, i.e., normal. Experimental results indicate that the proposed technique outperforms the ARX-Laguerre proportional integral observation (ALPIO) technique, yielding 18.82%, 16.825%, and 17.44% performance improvements for three levels of crack severity of 0.007, 0.014, and 0.021 inches, respectively.

Evaluation of three new laser spectrometer techniques for in-situ carbon monoxide measurements

NASA Astrophysics Data System (ADS)

Zellweger, C.; Steinbacher, M.; Buchmann, B.

2012-07-01

Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. However, the current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came on the market with promising properties for trace gas analytics. The current study compares three instruments that are recently commercially available (since 2011) with the up to now best available technique (vacuum UV fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques provide a considerably better performance compared to previous techniques, although some issues such as temperature influence and cross sensitivities need further attention.

Percutaneous Endovascular Salvage Techniques for Implanted Venous Access Device Dysfunction

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

Breault, Stéphane, E-mail: stephane.breault@chuv.ch; Glauser, Frédéric, E-mail: frederic.glauser@chuv.ch; Babaker, Malik, E-mail: malik.babaker@chuv.ch

2015-06-15

PurposeImplanted venous access devices (IVADs) are often used in patients who require long-term intravenous drug administration. The most common causes of device dysfunction include occlusion by fibrin sheath and/or catheter adherence to the vessel wall. We present percutaneous endovascular salvage techniques to restore function in occluded catheters. The aim of this study was to evaluate the feasibility, safety, and efficacy of these techniques.Methods and MaterialsThrough a femoral or brachial venous access, a snare is used to remove fibrin sheath around the IVAD catheter tip. If device dysfunction is caused by catheter adherences to the vessel wall, a new “mechanical adhesiolysis”more » maneuver was performed. IVAD salvage procedures performed between 2005 and 2013 were analyzed. Data included clinical background, catheter tip position, success rate, recurrence, and rate of complication.ResultsEighty-eight salvage procedures were performed in 80 patients, mostly women (52.5 %), with a mean age of 54 years. Only a minority (17.5 %) of evaluated catheters were located at an optimal position (i.e., cavoatrial junction ±1 cm). Mechanical adhesiolysis or other additional maneuvers were used in 21 cases (24 %). Overall technical success rate was 93.2 %. Malposition and/or vessel wall adherences were the main cause of technical failure. No complications were noted.ConclusionThese IVAD salvage techniques are safe and efficient. When a catheter is adherent to the vessel wall, mechanical adhesiolysis maneuvers allow catheter mobilization and a greater success rate with no additional risk. In patients who still require long-term use of their IVAD, these procedures can be performed safely to avoid catheter replacement.« less

Higher cost of single incision laparoscopic cholecystectomy due to longer operating time. A study of opportunity cost based on meta-analysis

PubMed Central

GIRABENT-FARRÉS, M.

2018-01-01

Background We aimed to calculate the opportunity cost of the operating time to demonstrate that single incision laparoscopic cholecystectomy (SILC) is more expensive than classic laparoscopic cholecystectomy (CLC). Methods We identified studies comparing use of both techniques during the period 2008–2016, and to calculate the opportunity cost, we performed another search in the same period of time with an economic evaluation of classic laparoscopy. We performed a meta-analysis of the items selected in the first review considering the cost of surgery and surgical time, and we analyzed their differences. We subsequently calculated the opportunity cost of these time differences based on the design of a cost/time variable using the data from the second literature review. Results Twenty-seven articles were selected from the first review: 26 for operating time (3.138 patients) and 3 for the cost of surgery (831 patients), and 3 articles from the second review. Both techniques have similar operating costs. Single incision laparoscopy surgery takes longer (16.90min) to perform (p <0.00001) and this difference represents an opportunity cost of 755.97 € (cost/time unit factor of 44.73 €/min). Conclusions SILC costs the same as CLC, but the surgery takes longer to perform, and this difference involves an opportunity cost that increases the total cost of SILC. The value of the opportunity cost of the operating time can vary the total cost of a surgical technique and it should be included in the economic evaluation to support the decision to adopt a new surgical technique. PMID:29549678

Secondary metabolites isolation in natural products chemistry: comparison of two semipreparative chromatographic techniques (high pressure liquid chromatography and high performance thin-layer chromatography).

PubMed

Do, Thi Kieu Tiên; Hadji-Minaglou, Francis; Antoniotti, Sylvain; Fernandez, Xavier

2014-01-17

Chemical investigations on secondary metabolites in natural products chemistry require efficient isolation techniques for characterization purpose as well as for the evaluation of their biological properties. In the case of phytochemical studies, the performance of the techniques is critical (resolution and yield) since the products generally present a narrow range of polarity and physicochemical properties. Several techniques are currently available, but HPLC (preparative and semipreparative) is the most widely used. To compare the performance of semipreparative HPLC and HPTLC for the isolation of secondary metabolites in different types of extracts, we have chosen carvone from spearmint essential oil (Mentha spicata L.), resveratrol from Fallopia multiflora (Thunb.) Haraldson, and rosmarinic acid from rosemary (Rosmarinus officinalis L.) extracts. The comparison was based on the chromatographic separation, the purity and quantity of isolated compounds, the solvent consumption, the duration and the cost of the isolation operations. The results showed that semipreparative HPTLC can in some case offer some advantages over conventional semipreparative HPLC. Copyright © 2013 Elsevier B.V. All rights reserved.

Aggregation in Network Models for Transportation Planning

DOT National Transportation Integrated Search

1978-02-01

This report documents research performed on techniques of aggregation applied to network models used in transportation planning. The central objective of this research has been to identify, extend, and evaluate methods of aggregation so as to improve...

Scale Issues in Air Quality Modeling

EPA Science Inventory

This presentation reviews past model evaluation studies investigating the impact of horizontal grid spacing on model performance. It also presents several examples of using a spectral decomposition technique to separate the forcings from processes operating on different time scal...

Assessing Cartilage Biomechanical Properties: Techniques for Evaluating the Functional Performance of Cartilage in Health and Disease.

PubMed

Lakin, Benjamin A; Snyder, Brian D; Grinstaff, Mark W

2017-06-21

Osteoarthritis (OA) affects millions of people and results in weakened hyaline cartilage due to overloading. During joint articulation, hyaline cartilage must withstand high loads while maintaining low friction to prevent wear and tissue loss. Thus, cartilage compressive stiffness and the coefficient of friction are important indicators of the tissue's functional performance. These mechanical properties are often measured ex vivo using mechanical testing regimens, but arthroscopic handheld probes (e.g., for indentation testing, ultrasound, and optical coherence tomography) and noninvasive imaging modalities (e.g., magnetic resonance imaging and computed tomography) provide opportunities for either direct or indirect in vivo assessment of cartilage mechanical properties. In this review, we examine the application of these techniques for evaluating cartilage, with a focus on measuring mechanical properties for early-stage OA diagnosis. For each approach, we discuss the advantages, disadvantages, current and potential clinical utility, and promising technological improvement.

ICC '86; Proceedings of the International Conference on Communications, Toronto, Canada, June 22-25, 1986, Conference Record. Volumes 1, 2, & 3

NASA Astrophysics Data System (ADS)

Papers are presented on ISDN, mobile radio systems and techniques for digital connectivity, centralized and distributed algorithms in computer networks, communications networks, quality assurance and impact on cost, adaptive filters in communications, the spread spectrum, signal processing, video communication techniques, and digital satellite services. Topics discussed include performance evaluation issues for integrated protocols, packet network operations, the computer network theory and multiple-access, microwave single sideband systems, switching architectures, fiber optic systems, wireless local communications, modulation, coding, and synchronization, remote switching, software quality, transmission, and expert systems in network operations. Consideration is given to wide area networks, image and speech processing, office communications application protocols, multimedia systems, customer-controlled network operations, digital radio systems, channel modeling and signal processing in digital communications, earth station/on-board modems, computer communications system performance evaluation, source encoding, compression, and quantization, and adaptive communications systems.

Neurophysiological testing in anorectal disorders

PubMed Central

Remes-Troche, Jose M; Rao, Satish SC

2013-01-01

Neurophysiological tests of anorectal function can provide useful information regarding the integrity of neuronal innervation, as well as neuromuscular function. This information can give insights regarding the pathophysiological mechanisms that lead to several disorders of anorectal function, particularly fecal incontinence, pelvic floor disorders and dyssynergic defecation. Currently, several tests are available for the neurophysiological evaluation of anorectal function. These tests are mostly performed on patients referred to tertiary care centers, either following negative evaluations or when there is lack of response to conventional therapy. Judicious use of these tests can reveal significant and new understanding of the underlying mechanism(s) that could pave the way for better management of these disorders. In addition, these techniques are complementary to other modalities of investigation, such as pelvic floor imaging. The most commonly performed neurophysiological tests, along with their indications and clinical utility are discussed. Several novel techniques are evolving that may reveal new information on brain–gut interactions. PMID:19072383

Performance of nanocomposites for preservation of artistic stones

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

Giancristofaro, Cristina; Pilloni, Luciano; Rinaldi, Antonio

2014-06-19

In this work, the effectiveness of nanocomposite surface treatments as protective systems for artistic stones was evaluated. Pyrolitic silica and titania nanoparticles were dispersed in a commercial silicon-based polymer and applied on marble and travertine samples. Artificial aging processes, both in climatic chamber and in solar box, were carried out to simulate real degradation processes in terms of photo-thermal effects and physical-chemical damage. The performances of the nanocomposites used as consolidant were evaluated comparatively by means of diverse diagnostic techniques, namely: scanning electron microscopy (SEM), laser induced fluorescence (LIF), ultrasonic technique, colorimetry, total immersion water absorption and contact angle. Themore » results show that some properties of conservation materials can be improved by the presences of nanoparticles because they induce substantial changes of surface morphology of the coating layer and counter the physical damage observed during artificial weathering.« less

Woven TPS Mechanical Property Evaluation

NASA Technical Reports Server (NTRS)

Gonzales, Gregory Lewis; Kao, David Jan-Woei; Stackpoole, Margaret M.

2013-01-01

Woven Thermal Protection Systems (WTPS) is a relatively new program funded by the Office of the Chief Technologist (OCT). The WTPS approach to producing TPS architectures uses precisely engineered 3-D weaving techniques that allow tailoring material characteristics needed to meet specific mission requirements. A series of mechanical tests were performed to evaluate performance of different weave types, and get a better understanding of failure modes expected in these three-dimensional architectures. These properties will aid in material down selection and guide selection of the appropriate WTPS for a potential mission.

The MSFC UNIVAC 1108 EXEC 8 simulation model

NASA Technical Reports Server (NTRS)

Williams, T. G.; Richards, F. M.; Weatherbee, J. E.; Paul, L. K.

1972-01-01

A model is presented which simulates the MSFC Univac 1108 multiprocessor system. The hardware/operating system is described to enable a good statistical measurement of the system behavior. The performance of the 1108 is evaluated by performing twenty-four different experiments designed to locate system bottlenecks and also to test the sensitivity of system throughput with respect to perturbation of the various Exec 8 scheduling algorithms. The model is implemented in the general purpose system simulation language and the techniques described can be used to assist in the design, development, and evaluation of multiprocessor systems.

Robust Adaptive Data Encoding and Restoration

NASA Technical Reports Server (NTRS)

Park, Stephen K.; Rahman, Zia-ur; Halyo, Nesim

2000-01-01

This is the final report for NASA cooperative agreement and covers the period from 01 October, 1997 to 11 April, 2000. The research during this period was performed in three primary, but related, areas. 1. Evaluation of integrated information adaptive imaging. 2. Improvements in memory utilization and performance of the multiscale retinex with color restoration (MSRCR). 3. Commencement of a theoretical study to evaluate the non-linear retinex image enhancement technique. The research resulted in several publications, and an intellectual property disclosure to the NASA patent council in May, 1999.

Performance Analysis of Hospital Managers Using Fuzzy AHP and Fuzzy TOPSIS: Iranian Experience.

PubMed

Shafii, Milad; Hosseini, Seyed Mostafa; Arab, Mohammad; Asgharizadeh, Ezzatollah; Farzianpour, Fereshteh

2015-06-12

Hospitals are complex organizations that require strong and effective management. The success of such organizations depends on the performance of managers. This study provides a comprehensive set of indicators to assess the performance of hospital managers in Iranian Ministry of Health owned hospitals. This research was a cross-sectional study. First, reviewing the literature and using experts' viewpoints and convening a panel of experts, the dimensions of performance have been selected and came in the form of a performance model. Then, using Fuzzy Analytic Hierarchy Process (FAHP), the chosen dimensions were weighted. Finally, based on the weighted performance dimensions, a questionnaire was designed and after confirming the reliability and validity, through a census, 407 senior and middle managers from 10 hospitals in Yazd, Iran completed it and performance of CEOs in these hospitals was evaluated using the Fuzzy Technique for Order Preference by Similarity Ideal Solution (FTOPSIS). To measure the performance of hospital managers, a performance assessment model consisted of 19 sub-dimensions in 5 main dimensions (Functional, Professional, Organizational, Individual and Human) was developed. The functional area had the most weight and the individual area had the least weight, as well. The hospital managers had different performance levels in each category and sub-dimensions. In terms of overall performance, the hospital managers C and H had the best and the worst performance, respectively. The use of appropriate dimensions for performance, prioritizing them and evaluating the performance of hospital managers using appropriate techniques, can play an effective role in the selection of qualified managers, identifying strengths and weaknesses in performance and continuous improvement of them.

A no-gold-standard technique for objective assessment of quantitative nuclear-medicine imaging methods

PubMed Central

Jha, Abhinav K; Caffo, Brian; Frey, Eric C

2016-01-01

The objective optimization and evaluation of nuclear-medicine quantitative imaging methods using patient data is highly desirable but often hindered by the lack of a gold standard. Previously, a regression-without-truth (RWT) approach has been proposed for evaluating quantitative imaging methods in the absence of a gold standard, but this approach implicitly assumes that bounds on the distribution of true values are known. Several quantitative imaging methods in nuclear-medicine imaging measure parameters where these bounds are not known, such as the activity concentration in an organ or the volume of a tumor. We extended upon the RWT approach to develop a no-gold-standard (NGS) technique for objectively evaluating such quantitative nuclear-medicine imaging methods with patient data in the absence of any ground truth. Using the parameters estimated with the NGS technique, a figure of merit, the noise-to-slope ratio (NSR), can be computed, which can rank the methods on the basis of precision. An issue with NGS evaluation techniques is the requirement of a large number of patient studies. To reduce this requirement, the proposed method explored the use of multiple quantitative measurements from the same patient, such as the activity concentration values from different organs in the same patient. The proposed technique was evaluated using rigorous numerical experiments and using data from realistic simulation studies. The numerical experiments demonstrated that the NSR was estimated accurately using the proposed NGS technique when the bounds on the distribution of true values were not precisely known, thus serving as a very reliable metric for ranking the methods on the basis of precision. In the realistic simulation study, the NGS technique was used to rank reconstruction methods for quantitative single-photon emission computed tomography (SPECT) based on their performance on the task of estimating the mean activity concentration within a known volume of interest. Results showed that the proposed technique provided accurate ranking of the reconstruction methods for 97.5% of the 50 noise realizations. Further, the technique was robust to the choice of evaluated reconstruction methods. The simulation study pointed to possible violations of the assumptions made in the NGS technique under clinical scenarios. However, numerical experiments indicated that the NGS technique was robust in ranking methods even when there was some degree of such violation. PMID:26982626

A no-gold-standard technique for objective assessment of quantitative nuclear-medicine imaging methods.

PubMed

Jha, Abhinav K; Caffo, Brian; Frey, Eric C

2016-04-07

The objective optimization and evaluation of nuclear-medicine quantitative imaging methods using patient data is highly desirable but often hindered by the lack of a gold standard. Previously, a regression-without-truth (RWT) approach has been proposed for evaluating quantitative imaging methods in the absence of a gold standard, but this approach implicitly assumes that bounds on the distribution of true values are known. Several quantitative imaging methods in nuclear-medicine imaging measure parameters where these bounds are not known, such as the activity concentration in an organ or the volume of a tumor. We extended upon the RWT approach to develop a no-gold-standard (NGS) technique for objectively evaluating such quantitative nuclear-medicine imaging methods with patient data in the absence of any ground truth. Using the parameters estimated with the NGS technique, a figure of merit, the noise-to-slope ratio (NSR), can be computed, which can rank the methods on the basis of precision. An issue with NGS evaluation techniques is the requirement of a large number of patient studies. To reduce this requirement, the proposed method explored the use of multiple quantitative measurements from the same patient, such as the activity concentration values from different organs in the same patient. The proposed technique was evaluated using rigorous numerical experiments and using data from realistic simulation studies. The numerical experiments demonstrated that the NSR was estimated accurately using the proposed NGS technique when the bounds on the distribution of true values were not precisely known, thus serving as a very reliable metric for ranking the methods on the basis of precision. In the realistic simulation study, the NGS technique was used to rank reconstruction methods for quantitative single-photon emission computed tomography (SPECT) based on their performance on the task of estimating the mean activity concentration within a known volume of interest. Results showed that the proposed technique provided accurate ranking of the reconstruction methods for 97.5% of the 50 noise realizations. Further, the technique was robust to the choice of evaluated reconstruction methods. The simulation study pointed to possible violations of the assumptions made in the NGS technique under clinical scenarios. However, numerical experiments indicated that the NGS technique was robust in ranking methods even when there was some degree of such violation.

Optimal cooperative control synthesis of active displays

NASA Technical Reports Server (NTRS)

Garg, S.; Schmidt, D. K.

1985-01-01

A technique is developed that is intended to provide a systematic approach to synthesizing display augmentation for optimal manual control in complex, closed-loop tasks. A cooperative control synthesis technique, previously developed to design pilot-optimal control augmentation for the plant, is extended to incorporate the simultaneous design of performance enhancing displays. The technique utilizes an optimal control model of the man in the loop. It is applied to the design of a quickening control law for a display and a simple K/s(2) plant, and then to an F-15 type aircraft in a multi-channel task. Utilizing the closed loop modeling and analysis procedures, the results from the display design algorithm are evaluated and an analytical validation is performed. Experimental validation is recommended for future efforts.

A Hybrid Neural Network-Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics

NASA Technical Reports Server (NTRS)

Kobayashi, Takahisa; Simon, Donald L.

2001-01-01

In this paper, a model-based diagnostic method, which utilizes Neural Networks and Genetic Algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and Genetic Algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of Genetic Algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show this approach is promising for reliable diagnostics of aircraft engines.

Automated high-performance cIMT measurement techniques using patented AtheroEdge™: a screening and home monitoring system.

PubMed

Molinari, Filippo; Meiburger, Kristen M; Suri, Jasjit

2011-01-01

The evaluation of the carotid artery wall is fundamental for the assessment of cardiovascular risk. This paper presents the general architecture of an automatic strategy, which segments the lumen-intima and media-adventitia borders, classified under a class of Patented AtheroEdge™ systems (Global Biomedical Technologies, Inc, CA, USA). Guidelines to produce accurate and repeatable measurements of the intima-media thickness are provided and the problem of the different distance metrics one can adopt is confronted. We compared the results of a completely automatic algorithm that we developed with those of a semi-automatic algorithm, and showed final segmentation results for both techniques. The overall rationale is to provide user-independent high-performance techniques suitable for screening and remote monitoring.

Missile airframe simulation testbed: MANPADS (MAST-M) for test and evaluation of aircraft survivability equipment

NASA Astrophysics Data System (ADS)

Clements, Jim; Robinson, Richard; Bunt, Leslie; Robinson, Joe

2011-06-01

A number of techniques have been utilized to evaluate the performance of Aircraft Survivability Equipment (ASE) against threat Man-Portable Air Defense Systems (MANPADS). These techniques include flying actual threat MANPADS against stationary ASE with simulated aircraft signatures, testing installed ASE systems against simulated threat signatures, and laboratory hardware-in-the-loop (HWIL) testing with simulated aircraft and simulated missile signatures. All of these tests lack the realism of evaluating installed ASE against in-flight MANPADS on a terminal homing intercept path toward the actual ASE equipped aircraft. This limitation is due primarily to the current inability to perform non-destructive MANPADS/Aircraft flight testing. The U.S. Army Aviation and Missile Research and Development and Engineering Center (AMRDEC) is working to overcome this limitation with the development of a recoverable surrogate MANPADS missile system capable of engaging aircraft equipped with ASE while guaranteeing collision avoidance with the test aircraft. Under its Missile Airframe Simulation Testbed - MANPADS (MAST-M) program, the AMRDEC is developing a surrogate missile system which will utilize actual threat MANPADS seeker/guidance sections to control the flight of a surrogate missile which will perform a collision avoidance and recovery maneuver prior to intercept to insure non-destructive test and evaluation of the ASE and reuse of the MANPADS seeker/guidance section. The remainder of this paper provides an overview of this development program and intended use.