Reliability of Test Scores in Nonparametric Item Response Theory.

ERIC Educational Resources Information Center

Sijtsma, Klaas; Molenaar, Ivo W.

1987-01-01

Three methods for estimating reliability are studied within the context of nonparametric item response theory. Two were proposed originally by Mokken and a third is developed in this paper. Using a Monte Carlo strategy, these three estimation methods are compared with four "classical" lower bounds to reliability. (Author/JAZ)

Report: Eleven Years After Agreement, EPA Has Not Developed Reliable Emission Estimation Methods to Determine Whether Animal Feeding Operations Comply With Clean Air Act and Other Statutes

EPA Pesticide Factsheets

Report #17-P-0396, September 19, 2017. Until the EPA develops sound methods to estimate emissions, the agency cannot reliably determine whether animal feeding operations comply with applicable Clean Air Act requirements.

Reliability and Availability Evaluation Program Manual.

DTIC Science & Technology

1982-11-01

research and development. The manual’s purpose was to provide a practical method for making reliability measurements, measurements directly related to... Research , Development, Test and Evaluation. RMA Reliability, Maintainability and Availability. R&R Repair and Refurbishment, Repair and Replacement, etc...length. phenomena such as mechanical wear and A number of researchers in the reliability chemical deterioration. Maintenance should field 14-pages 402

Comprehensive Deployment Method for Technical Characteristics Base on Multi-failure Modes Correlation Analysis

NASA Astrophysics Data System (ADS)

Zheng, W.; Gao, J. M.; Wang, R. X.; Chen, K.; Jiang, Y.

2017-12-01

This paper put forward a new method of technical characteristics deployment based on Reliability Function Deployment (RFD) by analysing the advantages and shortages of related research works on mechanical reliability design. The matrix decomposition structure of RFD was used to describe the correlative relation between failure mechanisms, soft failures and hard failures. By considering the correlation of multiple failure modes, the reliability loss of one failure mode to the whole part was defined, and a calculation and analysis model for reliability loss was presented. According to the reliability loss, the reliability index value of the whole part was allocated to each failure mode. On the basis of the deployment of reliability index value, the inverse reliability method was employed to acquire the values of technology characteristics. The feasibility and validity of proposed method were illustrated by a development case of machining centre’s transmission system.

National audit of continence care: laying the foundation.

PubMed

Mian, Sarah; Wagg, Adrian; Irwin, Penny; Lowe, Derek; Potter, Jonathan; Pearson, Michael

2005-12-01

National audit provides a basis for establishing performance against national standards, benchmarking against other service providers and improving standards of care. For effective audit, clinical indicators are required that are valid, feasible to apply and reliable. This study describes the methods used to develop clinical indicators of continence care in preparation for a national audit. To describe the methods used to develop and test clinical indicators of continence care with regard to validity, feasibility and reliability. A multidisciplinary working group developed clinical indicators that measured the structure, process and outcome of care as well as case-mix variables. Literature searching, consensus workshops and a Delphi process were used to develop the indicators. The indicators were tested in 15 secondary care sites, 15 primary care sites and 15 long-term care settings. The process of development produced indicators that received a high degree of consensus within the Delphi process. Testing of the indicators demonstrated an internal reliability of 0.7 and an external reliability of 0.6. Data collection required significant investment in terms of staff time and training. The method used produced indicators that achieved a high degree of acceptance from health care professionals. The reliability of data collection was high for this audit and was similar to the level seen in other successful national audits. Data collection for the indicators was feasible to collect, however, issues of time and staffing were identified as limitations to such data collection. The study has described a systematic method for developing clinical indicators for national audit. The indicators proved robust and reliable in primary and secondary care as well as long-term care settings.

Reliability and coverage analysis of non-repairable fault-tolerant memory systems

NASA Technical Reports Server (NTRS)

Cox, G. W.; Carroll, B. D.

1976-01-01

A method was developed for the construction of probabilistic state-space models for nonrepairable systems. Models were developed for several systems which achieved reliability improvement by means of error-coding, modularized sparing, massive replication and other fault-tolerant techniques. From the models developed, sets of reliability and coverage equations for the systems were developed. Comparative analyses of the systems were performed using these equation sets. In addition, the effects of varying subunit reliabilities on system reliability and coverage were described. The results of these analyses indicated that a significant gain in system reliability may be achieved by use of combinations of modularized sparing, error coding, and software error control. For sufficiently reliable system subunits, this gain may far exceed the reliability gain achieved by use of massive replication techniques, yet result in a considerable saving in system cost.

Computational methods for efficient structural reliability and reliability sensitivity analysis

NASA Technical Reports Server (NTRS)

Wu, Y.-T.

1993-01-01

This paper presents recent developments in efficient structural reliability analysis methods. The paper proposes an efficient, adaptive importance sampling (AIS) method that can be used to compute reliability and reliability sensitivities. The AIS approach uses a sampling density that is proportional to the joint PDF of the random variables. Starting from an initial approximate failure domain, sampling proceeds adaptively and incrementally with the goal of reaching a sampling domain that is slightly greater than the failure domain to minimize over-sampling in the safe region. Several reliability sensitivity coefficients are proposed that can be computed directly and easily from the above AIS-based failure points. These probability sensitivities can be used for identifying key random variables and for adjusting design to achieve reliability-based objectives. The proposed AIS methodology is demonstrated using a turbine blade reliability analysis problem.

Probability techniques for reliability analysis of composite materials

NASA Technical Reports Server (NTRS)

Wetherhold, Robert C.; Ucci, Anthony M.

1994-01-01

Traditional design approaches for composite materials have employed deterministic criteria for failure analysis. New approaches are required to predict the reliability of composite structures since strengths and stresses may be random variables. This report will examine and compare methods used to evaluate the reliability of composite laminae. The two types of methods that will be evaluated are fast probability integration (FPI) methods and Monte Carlo methods. In these methods, reliability is formulated as the probability that an explicit function of random variables is less than a given constant. Using failure criteria developed for composite materials, a function of design variables can be generated which defines a 'failure surface' in probability space. A number of methods are available to evaluate the integration over the probability space bounded by this surface; this integration delivers the required reliability. The methods which will be evaluated are: the first order, second moment FPI methods; second order, second moment FPI methods; the simple Monte Carlo; and an advanced Monte Carlo technique which utilizes importance sampling. The methods are compared for accuracy, efficiency, and for the conservativism of the reliability estimation. The methodology involved in determining the sensitivity of the reliability estimate to the design variables (strength distributions) and importance factors is also presented.

A pilot study to explore the feasibility of using theClinical Care Classification System for developing a reliable costing method for nursing services.

PubMed

Dykes, Patricia C; Wantland, Dean; Whittenburg, Luann; Lipsitz, Stuart; Saba, Virginia K

2013-01-01

While nursing activities represent a significant proportion of inpatient care, there are no reliable methods for determining nursing costs based on the actual services provided by the nursing staff. Capture of data to support accurate measurement and reporting on the cost of nursing services is fundamental to effective resource utilization. Adopting standard terminologies that support tracking both the quality and the cost of care could reduce the data entry burden on direct care providers. This pilot study evaluated the feasibility of using a standardized nursing terminology, the Clinical Care Classification System (CCC), for developing a reliable costing method for nursing services. Two different approaches are explored; the Relative Value Unit RVU and the simple cost-to-time methods. We found that the simple cost-to-time method was more accurate and more transparent in its derivation than the RVU method and may support a more consistent and reliable approach for costing nursing services.

Developing a method for specifying the components of behavior change interventions in practice: the example of smoking cessation.

PubMed

Lorencatto, Fabiana; West, Robert; Seymour, Natalie; Michie, Susan

2013-06-01

There is a difference between interventions as planned and as delivered in practice. Unless we know what was actually delivered, we cannot understand "what worked" in effective interventions. This study aimed to (a) assess whether an established taxonomy of 53 smoking cessation behavior change techniques (BCTs) may be applied or adapted as a method for reliably specifying the content of smoking cessation behavioral support consultations and (b) develop an effective method for training researchers and practitioners in the reliable application of the taxonomy. Fifteen transcripts of audio-recorded consultations delivered by England's Stop Smoking Services were coded into component BCTs using the taxonomy. Interrater reliability and potential adaptations to the taxonomy to improve coding were discussed following 3 coding waves. A coding training manual was developed through expert consensus and piloted on 10 trainees, assessing coding reliability and self-perceived competence before and after training. An average of 33 BCTs from the taxonomy were identified at least once across sessions and coding waves. Consultations contained on average 12 BCTs (range = 8-31). Average interrater reliability was high (88% agreement). The taxonomy was adapted to simplify coding by merging co-occurring BCTs and refining BCT definitions. Coding reliability and self-perceived competence significantly improved posttraining for all trainees. It is possible to apply a taxonomy to reliably identify and classify BCTs in smoking cessation behavioral support delivered in practice, and train inexperienced coders to do so reliably. This method can be used to investigate variability in provision of behavioral support across services, monitor fidelity of delivery, and identify training needs.

Reliability apportionment approach for spacecraft solar array using fuzzy reasoning Petri net and fuzzy comprehensive evaluation

NASA Astrophysics Data System (ADS)

Wu, Jianing; Yan, Shaoze; Xie, Liyang; Gao, Peng

2012-07-01

The reliability apportionment of spacecraft solar array is of significant importance for spacecraft designers in the early stage of design. However, it is difficult to use the existing methods to resolve reliability apportionment problem because of the data insufficiency and the uncertainty of the relations among the components in the mechanical system. This paper proposes a new method which combines the fuzzy comprehensive evaluation with fuzzy reasoning Petri net (FRPN) to accomplish the reliability apportionment of the solar array. The proposed method extends the previous fuzzy methods and focuses on the characteristics of the subsystems and the intrinsic associations among the components. The analysis results show that the synchronization mechanism may obtain the highest reliability value and the solar panels and hinges may get the lowest reliability before design and manufacturing. Our developed method is of practical significance for the reliability apportionment of solar array where the design information has not been clearly identified, particularly in early stage of design.

Overview of Probabilistic Methods for SAE G-11 Meeting for Reliability and Uncertainty Quantification for DoD TACOM Initiative with SAE G-11 Division

NASA Technical Reports Server (NTRS)

Singhal, Surendra N.

2003-01-01

The SAE G-11 RMSL Division and Probabilistic Methods Committee meeting during October 6-8 at the Best Western Sterling Inn, Sterling Heights (Detroit), Michigan is co-sponsored by US Army Tank-automotive & Armaments Command (TACOM). The meeting will provide an industry/government/academia forum to review RMSL technology; reliability and probabilistic technology; reliability-based design methods; software reliability; and maintainability standards. With over 100 members including members with national/international standing, the mission of the G-11's Probabilistic Methods Committee is to "enable/facilitate rapid deployment of probabilistic technology to enhance the competitiveness of our industries by better, faster, greener, smarter, affordable and reliable product development."

Modeling, implementation, and validation of arterial travel time reliability.

DOT National Transportation Integrated Search

2013-11-01

Previous research funded by Florida Department of Transportation (FDOT) developed a method for estimating : travel time reliability for arterials. This method was not initially implemented or validated using field data. This : project evaluated and r...

Design for a Crane Metallic Structure Based on Imperialist Competitive Algorithm and Inverse Reliability Strategy

NASA Astrophysics Data System (ADS)

Fan, Xiao-Ning; Zhi, Bo

2017-07-01

Uncertainties in parameters such as materials, loading, and geometry are inevitable in designing metallic structures for cranes. When considering these uncertainty factors, reliability-based design optimization (RBDO) offers a more reasonable design approach. However, existing RBDO methods for crane metallic structures are prone to low convergence speed and high computational cost. A unilevel RBDO method, combining a discrete imperialist competitive algorithm with an inverse reliability strategy based on the performance measure approach, is developed. Application of the imperialist competitive algorithm at the optimization level significantly improves the convergence speed of this RBDO method. At the reliability analysis level, the inverse reliability strategy is used to determine the feasibility of each probabilistic constraint at each design point by calculating its α-percentile performance, thereby avoiding convergence failure, calculation error, and disproportionate computational effort encountered using conventional moment and simulation methods. Application of the RBDO method to an actual crane structure shows that the developed RBDO realizes a design with the best tradeoff between economy and safety together with about one-third of the convergence speed and the computational cost of the existing method. This paper provides a scientific and effective design approach for the design of metallic structures of cranes.

Development of a probabilistic analysis methodology for structural reliability estimation

NASA Technical Reports Server (NTRS)

Torng, T. Y.; Wu, Y.-T.

1991-01-01

The novel probabilistic analysis method for assessment of structural reliability presented, which combines fast-convolution with an efficient structural reliability analysis, can after identifying the most important point of a limit state proceed to establish a quadratic-performance function. It then transforms the quadratic function into a linear one, and applies fast convolution. The method is applicable to problems requiring computer-intensive structural analysis. Five illustrative examples of the method's application are given.

Production of Reliable Flight Crucial Software: Validation Methods Research for Fault Tolerant Avionics and Control Systems Sub-Working Group Meeting

NASA Technical Reports Server (NTRS)

Dunham, J. R. (Editor); Knight, J. C. (Editor)

1982-01-01

The state of the art in the production of crucial software for flight control applications was addressed. The association between reliability metrics and software is considered. Thirteen software development projects are discussed. A short term need for research in the areas of tool development and software fault tolerance was indicated. For the long term, research in format verification or proof methods was recommended. Formal specification and software reliability modeling, were recommended as topics for both short and long term research.

Development, scoring, and reliability of the Microscale Audit of Pedestrian Streetscapes (MAPS)

PubMed Central

2013-01-01

Background Streetscape (microscale) features of the built environment can influence people’s perceptions of their neighborhoods’ suitability for physical activity. Many microscale audit tools have been developed, but few have published systematic scoring methods. We present the development, scoring, and reliability of the Microscale Audit of Pedestrian Streetscapes (MAPS) tool and its theoretically-based subscales. Methods MAPS was based on prior instruments and was developed to assess details of streetscapes considered relevant for physical activity. MAPS sections (route, segments, crossings, and cul-de-sacs) were scored by two independent raters for reliability analyses. There were 290 route pairs, 516 segment pairs, 319 crossing pairs, and 53 cul-de-sac pairs in the reliability sample. Individual inter-rater item reliability analyses were computed using Kappa, intra-class correlation coefficient (ICC), and percent agreement. A conceptual framework for subscale creation was developed using theory, expert consensus, and policy relevance. Items were grouped into subscales, and subscales were analyzed for inter-rater reliability at tiered levels of aggregation. Results There were 160 items included in the subscales (out of 201 items total). Of those included in the subscales, 80 items (50.0%) had good/excellent reliability, 41 items (25.6%) had moderate reliability, and 18 items (11.3%) had low reliability, with limited variability in the remaining 21 items (13.1%). Seventeen of the 20 route section subscales, valence (positive/negative) scores, and overall scores (85.0%) demonstrated good/excellent reliability and 3 demonstrated moderate reliability. Of the 16 segment subscales, valence scores, and overall scores, 12 (75.0%) demonstrated good/excellent reliability, three demonstrated moderate reliability, and one demonstrated poor reliability. Of the 8 crossing subscales, valence scores, and overall scores, 6 (75.0%) demonstrated good/excellent reliability, and 2 demonstrated moderate reliability. The cul-de-sac subscale demonstrated good/excellent reliability. Conclusions MAPS items and subscales predominantly demonstrated moderate to excellent reliability. The subscales and scoring system represent a theoretically based framework for using these complex microscale data and may be applicable to other similar instruments. PMID:23621947

Scale for positive aspects of caregiving experience: development, reliability, and factor structure.

PubMed

Kate, N; Grover, S; Kulhara, P; Nehra, R

2012-06-01

OBJECTIVE. To develop an instrument (Scale for Positive Aspects of Caregiving Experience [SPACE]) that evaluates positive caregiving experience and assess its psychometric properties. METHODS. Available scales which assess some aspects of positive caregiving experience were reviewed and a 50-item questionnaire with a 5-point rating was constructed. In all, 203 primary caregivers of patients with severe mental disorders were asked to complete the questionnaire. Internal consistency, test-retest reliability, cross-language reliability, split-half reliability, and face validity were evaluated. Principal component factor analysis was run to assess the factorial validity of the scale. RESULTS. The scale developed as part of the study was found to have good internal consistency, test-retest reliability, cross-language reliability, split-half reliability, and face validity. Principal component factor analysis yielded a 4-factor structure, which also had good test-retest reliability and cross-language reliability. There was a strong correlation between the 4 factors obtained. CONCLUSION. The SPACE developed as part of this study has good psychometric properties.

A single-loop optimization method for reliability analysis with second order uncertainty

NASA Astrophysics Data System (ADS)

Xie, Shaojun; Pan, Baisong; Du, Xiaoping

2015-08-01

Reliability analysis may involve random variables and interval variables. In addition, some of the random variables may have interval distribution parameters owing to limited information. This kind of uncertainty is called second order uncertainty. This article develops an efficient reliability method for problems involving the three aforementioned types of uncertain input variables. The analysis produces the maximum and minimum reliability and is computationally demanding because two loops are needed: a reliability analysis loop with respect to random variables and an interval analysis loop for extreme responses with respect to interval variables. The first order reliability method and nonlinear optimization are used for the two loops, respectively. For computational efficiency, the two loops are combined into a single loop by treating the Karush-Kuhn-Tucker (KKT) optimal conditions of the interval analysis as constraints. Three examples are presented to demonstrate the proposed method.

Aerospace reliability applied to biomedicine.

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Vargo, D. J.

1972-01-01

An analysis is presented that indicates that the reliability and quality assurance methodology selected by NASA to minimize failures in aerospace equipment can be applied directly to biomedical devices to improve hospital equipment reliability. The Space Electric Rocket Test project is used as an example of NASA application of reliability and quality assurance (R&QA) methods. By analogy a comparison is made to show how these same methods can be used in the development of transducers, instrumentation, and complex systems for use in medicine.

Dynamic one-dimensional modeling of secondary settling tanks and system robustness evaluation.

PubMed

Li, Ben; Stenstrom, M K

2014-01-01

One-dimensional secondary settling tank models are widely used in current engineering practice for design and optimization, and usually can be expressed as a nonlinear hyperbolic or nonlinear strongly degenerate parabolic partial differential equation (PDE). Reliable numerical methods are needed to produce approximate solutions that converge to the exact analytical solutions. In this study, we introduced a reliable numerical technique, the Yee-Roe-Davis (YRD) method as the governing PDE solver, and compared its reliability with the prevalent Stenstrom-Vitasovic-Takács (SVT) method by assessing their simulation results at various operating conditions. The YRD method also produced a similar solution to the previously developed Method G and Enquist-Osher method. The YRD and SVT methods were also used for a time-to-failure evaluation, and the results show that the choice of numerical method can greatly impact the solution. Reliable numerical methods, such as the YRD method, are strongly recommended.

Probabilistic Structural Analysis Methods (PSAM) for select space propulsion system components, part 2

NASA Technical Reports Server (NTRS)

1991-01-01

The technical effort and computer code enhancements performed during the sixth year of the Probabilistic Structural Analysis Methods program are summarized. Various capabilities are described to probabilistically combine structural response and structural resistance to compute component reliability. A library of structural resistance models is implemented in the Numerical Evaluations of Stochastic Structures Under Stress (NESSUS) code that included fatigue, fracture, creep, multi-factor interaction, and other important effects. In addition, a user interface was developed for user-defined resistance models. An accurate and efficient reliability method was developed and was successfully implemented in the NESSUS code to compute component reliability based on user-selected response and resistance models. A risk module was developed to compute component risk with respect to cost, performance, or user-defined criteria. The new component risk assessment capabilities were validated and demonstrated using several examples. Various supporting methodologies were also developed in support of component risk assessment.

NASA Applications and Lessons Learned in Reliability Engineering

NASA Technical Reports Server (NTRS)

Safie, Fayssal M.; Fuller, Raymond P.

2011-01-01

Since the Shuttle Challenger accident in 1986, communities across NASA have been developing and extensively using quantitative reliability and risk assessment methods in their decision making process. This paper discusses several reliability engineering applications that NASA has used over the year to support the design, development, and operation of critical space flight hardware. Specifically, the paper discusses several reliability engineering applications used by NASA in areas such as risk management, inspection policies, components upgrades, reliability growth, integrated failure analysis, and physics based probabilistic engineering analysis. In each of these areas, the paper provides a brief discussion of a case study to demonstrate the value added and the criticality of reliability engineering in supporting NASA project and program decisions to fly safely. Examples of these case studies discussed are reliability based life limit extension of Shuttle Space Main Engine (SSME) hardware, Reliability based inspection policies for Auxiliary Power Unit (APU) turbine disc, probabilistic structural engineering analysis for reliability prediction of the SSME alternate turbo-pump development, impact of ET foam reliability on the Space Shuttle System risk, and reliability based Space Shuttle upgrade for safety. Special attention is given in this paper to the physics based probabilistic engineering analysis applications and their critical role in evaluating the reliability of NASA development hardware including their potential use in a research and technology development environment.

Mechanical system reliability for long life space systems

NASA Technical Reports Server (NTRS)

Kowal, Michael T.

1994-01-01

The creation of a compendium of mechanical limit states was undertaken in order to provide a reference base for the application of first-order reliability methods to mechanical systems in the context of the development of a system level design methodology. The compendium was conceived as a reference source specific to the problem of developing the noted design methodology, and not an exhaustive or exclusive compilation of mechanical limit states. The compendium is not intended to be a handbook of mechanical limit states for general use. The compendium provides a diverse set of limit-state relationships for use in demonstrating the application of probabilistic reliability methods to mechanical systems. The compendium is to be used in the reliability analysis of moderately complex mechanical systems.

Developing Confidence Limits For Reliability Of Software

NASA Technical Reports Server (NTRS)

Hayhurst, Kelly J.

1991-01-01

Technique developed for estimating reliability of software by use of Moranda geometric de-eutrophication model. Pivotal method enables straightforward construction of exact bounds with associated degree of statistical confidence about reliability of software. Confidence limits thus derived provide precise means of assessing quality of software. Limits take into account number of bugs found while testing and effects of sampling variation associated with random order of discovering bugs.

Approach to developing reliable space reactor power systems

NASA Technical Reports Server (NTRS)

Mondt, Jack F.; Shinbrot, Charles H.

1991-01-01

During Phase II, the Engineering Development Phase, the SP-100 Project has defined and is pursuing a new approach to developing reliable power systems. The approach to developing such a system during the early technology phase is described along with some preliminary examples to help explain the approach. Developing reliable components to meet space reactor power system requirements is based on a top-down systems approach which includes a point design based on a detailed technical specification of a 100-kW power system. The SP-100 system requirements implicitly recognize the challenge of achieving a high system reliability for a ten-year lifetime, while at the same time using technologies that require very significant development efforts. A low-cost method for assessing reliability, based on an understanding of fundamental failure mechanisms and design margins for specific failure mechanisms, is being developed as part of the SP-100 Program.

Development Of Methodologies Using PhabrOmeter For Fabric Drape Evaluation

NASA Astrophysics Data System (ADS)

Lin, Chengwei

Evaluation of fabric drape is important for textile industry as it reveals the aesthetic and functionality of the cloth and apparel. Although many fabric drape measuring methods have been developed for several decades, they are falling behind the need for fast product development by the industry. To meet the requirement of industries, it is necessary to develop an effective and reliable method to evaluate fabric drape. The purpose of the present study is to determine if PhabrOmeter can be applied to fabric drape evaluation. PhabrOmeter is a fabric sensory performance evaluating instrument which is developed to provide fast and reliable quality testing results. This study was sought to determine the relationship between fabric drape and other fabric attributes. In addition, a series of conventional methods including AATCC standards, ASTM standards and ISO standards were used to characterize the fabric samples. All the data were compared and analyzed with linear correlation method. The results indicate that PhabrOmeter is reliable and effective instrument for fabric drape evaluation. Besides, some effects including fabric structure, testing directions were considered to examine their impact on fabric drape.

The Use of Invariance and Bootstrap Procedures as a Method to Establish the Reliability of Research Results.

ERIC Educational Resources Information Center

Sandler, Andrew B.

Statistical significance is misused in educational and psychological research when it is applied as a method to establish the reliability of research results. Other techniques have been developed which can be correctly utilized to establish the generalizability of findings. Methods that do provide such estimates are known as invariance or…

Robustness Analysis and Reliable Flight Regime Estimation of an Integrated Resilent Control System for a Transport Aircraft

NASA Technical Reports Server (NTRS)

Shin, Jong-Yeob; Belcastro, Christine

2008-01-01

Formal robustness analysis of aircraft control upset prevention and recovery systems could play an important role in their validation and ultimate certification. As a part of the validation process, this paper describes an analysis method for determining a reliable flight regime in the flight envelope within which an integrated resilent control system can achieve the desired performance of tracking command signals and detecting additive faults in the presence of parameter uncertainty and unmodeled dynamics. To calculate a reliable flight regime, a structured singular value analysis method is applied to analyze the closed-loop system over the entire flight envelope. To use the structured singular value analysis method, a linear fractional transform (LFT) model of a transport aircraft longitudinal dynamics is developed over the flight envelope by using a preliminary LFT modeling software tool developed at the NASA Langley Research Center, which utilizes a matrix-based computational approach. The developed LFT model can capture original nonlinear dynamics over the flight envelope with the ! block which contains key varying parameters: angle of attack and velocity, and real parameter uncertainty: aerodynamic coefficient uncertainty and moment of inertia uncertainty. Using the developed LFT model and a formal robustness analysis method, a reliable flight regime is calculated for a transport aircraft closed-loop system.

Establishing Inter- and Intrarater Reliability for High-Stakes Testing Using Simulation.

PubMed

Kardong-Edgren, Suzan; Oermann, Marilyn H; Rizzolo, Mary Anne; Odom-Maryon, Tamara

This article reports one method to develop a standardized training method to establish the inter- and intrarater reliability of a group of raters for high-stakes testing. Simulation is used increasingly for high-stakes testing, but without research into the development of inter- and intrarater reliability for raters. Eleven raters were trained using a standardized methodology. Raters scored 28 student videos over a six-week period. Raters then rescored all videos over a two-day period to establish both intra- and interrater reliability. One rater demonstrated poor intrarater reliability; a second rater failed all students. Kappa statistics improved from the moderate to substantial agreement range with the exclusion of the two outlier raters' scores. There may be faculty who, for different reasons, should not be included in high-stakes testing evaluations. All faculty are content experts, but not all are expert evaluators.

Reliability database development for use with an object-oriented fault tree evaluation program

NASA Technical Reports Server (NTRS)

Heger, A. Sharif; Harringtton, Robert J.; Koen, Billy V.; Patterson-Hine, F. Ann

1989-01-01

A description is given of the development of a fault-tree analysis method using object-oriented programming. In addition, the authors discuss the programs that have been developed or are under development to connect a fault-tree analysis routine to a reliability database. To assess the performance of the routines, a relational database simulating one of the nuclear power industry databases has been constructed. For a realistic assessment of the results of this project, the use of one of existing nuclear power reliability databases is planned.

A criterion for establishing life limits. [for Space Shuttle Main Engine service

NASA Technical Reports Server (NTRS)

Skopp, G. H.; Porter, A. A.

1990-01-01

The development of a rigorous statistical method that would utilize hardware-demonstrated reliability to evaluate hardware capability and provide ground rules for safe flight margin is discussed. A statistical-based method using the Weibull/Weibayes cumulative distribution function is described. Its advantages and inadequacies are pointed out. Another, more advanced procedure, Single Flight Reliability (SFR), determines a life limit which ensures that the reliability of any single flight is never less than a stipulated value at a stipulated confidence level. Application of the SFR method is illustrated.

Integrating Formal Methods and Testing 2002

NASA Technical Reports Server (NTRS)

Cukic, Bojan

2002-01-01

Traditionally, qualitative program verification methodologies and program testing are studied in separate research communities. None of them alone is powerful and practical enough to provide sufficient confidence in ultra-high reliability assessment when used exclusively. Significant advances can be made by accounting not only tho formal verification and program testing. but also the impact of many other standard V&V techniques, in a unified software reliability assessment framework. The first year of this research resulted in the statistical framework that, given the assumptions on the success of the qualitative V&V and QA procedures, significantly reduces the amount of testing needed to confidently assess reliability at so-called high and ultra-high levels (10-4 or higher). The coming years shall address the methodologies to realistically estimate the impacts of various V&V techniques to system reliability and include the impact of operational risk to reliability assessment. Combine formal correctness verification, process and product metrics, and other standard qualitative software assurance methods with statistical testing with the aim of gaining higher confidence in software reliability assessment for high-assurance applications. B) Quantify the impact of these methods on software reliability. C) Demonstrate that accounting for the effectiveness of these methods reduces the number of tests needed to attain certain confidence level. D) Quantify and justify the reliability estimate for systems developed using various methods.

Comparing Methods for Assessing Reliability Uncertainty Based on Pass/Fail Data Collected Over Time

DOE PAGES

Abes, Jeff I.; Hamada, Michael S.; Hills, Charles R.

2017-12-20

In this paper, we compare statistical methods for analyzing pass/fail data collected over time; some methods are traditional and one (the RADAR or Rationale for Assessing Degradation Arriving at Random) was recently developed. These methods are used to provide uncertainty bounds on reliability. We make observations about the methods' assumptions and properties. Finally, we illustrate the differences between two traditional methods, logistic regression and Weibull failure time analysis, and the RADAR method using a numerical example.

Comparing Methods for Assessing Reliability Uncertainty Based on Pass/Fail Data Collected Over Time

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

Abes, Jeff I.; Hamada, Michael S.; Hills, Charles R.

In this paper, we compare statistical methods for analyzing pass/fail data collected over time; some methods are traditional and one (the RADAR or Rationale for Assessing Degradation Arriving at Random) was recently developed. These methods are used to provide uncertainty bounds on reliability. We make observations about the methods' assumptions and properties. Finally, we illustrate the differences between two traditional methods, logistic regression and Weibull failure time analysis, and the RADAR method using a numerical example.

Overview of Future of Probabilistic Methods and RMSL Technology and the Probabilistic Methods Education Initiative for the US Army at the SAE G-11 Meeting

NASA Technical Reports Server (NTRS)

Singhal, Surendra N.

2003-01-01

The SAE G-11 RMSL Division and Probabilistic Methods Committee meeting sponsored by the Picatinny Arsenal during March 1-3, 2004 at Westin Morristown, will report progress on projects for probabilistic assessment of Army system and launch an initiative for probabilistic education. The meeting features several Army and industry Senior executives and Ivy League Professor to provide an industry/government/academia forum to review RMSL technology; reliability and probabilistic technology; reliability-based design methods; software reliability; and maintainability standards. With over 100 members including members with national/international standing, the mission of the G-11s Probabilistic Methods Committee is to enable/facilitate rapid deployment of probabilistic technology to enhance the competitiveness of our industries by better, faster, greener, smarter, affordable and reliable product development.

Software Reliability 2002

NASA Technical Reports Server (NTRS)

Wallace, Dolores R.

2003-01-01

In FY01 we learned that hardware reliability models need substantial changes to account for differences in software, thus making software reliability measurements more effective, accurate, and easier to apply. These reliability models are generally based on familiar distributions or parametric methods. An obvious question is 'What new statistical and probability models can be developed using non-parametric and distribution-free methods instead of the traditional parametric method?" Two approaches to software reliability engineering appear somewhat promising. The first study, begin in FY01, is based in hardware reliability, a very well established science that has many aspects that can be applied to software. This research effort has investigated mathematical aspects of hardware reliability and has identified those applicable to software. Currently the research effort is applying and testing these approaches to software reliability measurement, These parametric models require much project data that may be difficult to apply and interpret. Projects at GSFC are often complex in both technology and schedules. Assessing and estimating reliability of the final system is extremely difficult when various subsystems are tested and completed long before others. Parametric and distribution free techniques may offer a new and accurate way of modeling failure time and other project data to provide earlier and more accurate estimates of system reliability.

Statistical modeling of software reliability

NASA Technical Reports Server (NTRS)

Miller, Douglas R.

1992-01-01

This working paper discusses the statistical simulation part of a controlled software development experiment being conducted under the direction of the System Validation Methods Branch, Information Systems Division, NASA Langley Research Center. The experiment uses guidance and control software (GCS) aboard a fictitious planetary landing spacecraft: real-time control software operating on a transient mission. Software execution is simulated to study the statistical aspects of reliability and other failure characteristics of the software during development, testing, and random usage. Quantification of software reliability is a major goal. Various reliability concepts are discussed. Experiments are described for performing simulations and collecting appropriate simulated software performance and failure data. This data is then used to make statistical inferences about the quality of the software development and verification processes as well as inferences about the reliability of software versions and reliability growth under random testing and debugging.

Do you see what I see? Mobile eye-tracker contextual analysis and inter-rater reliability.

PubMed

Stuart, S; Hunt, D; Nell, J; Godfrey, A; Hausdorff, J M; Rochester, L; Alcock, L

2018-02-01

Mobile eye-trackers are currently used during real-world tasks (e.g. gait) to monitor visual and cognitive processes, particularly in ageing and Parkinson's disease (PD). However, contextual analysis involving fixation locations during such tasks is rarely performed due to its complexity. This study adapted a validated algorithm and developed a classification method to semi-automate contextual analysis of mobile eye-tracking data. We further assessed inter-rater reliability of the proposed classification method. A mobile eye-tracker recorded eye-movements during walking in five healthy older adult controls (HC) and five people with PD. Fixations were identified using a previously validated algorithm, which was adapted to provide still images of fixation locations (n = 116). The fixation location was manually identified by two raters (DH, JN), who classified the locations. Cohen's kappa correlation coefficients determined the inter-rater reliability. The algorithm successfully provided still images for each fixation, allowing manual contextual analysis to be performed. The inter-rater reliability for classifying the fixation location was high for both PD (kappa = 0.80, 95% agreement) and HC groups (kappa = 0.80, 91% agreement), which indicated a reliable classification method. This study developed a reliable semi-automated contextual analysis method for gait studies in HC and PD. Future studies could adapt this methodology for various gait-related eye-tracking studies.

Review on pen-and-paper-based observational methods for assessing ergonomic risk factors of computer work.

PubMed

Rahman, Mohd Nasrull Abdol; Mohamad, Siti Shafika

2017-01-01

Computer works are associated with Musculoskeletal Disorders (MSDs). There are several methods have been developed to assess computer work risk factor related to MSDs. This review aims to give an overview of current techniques available for pen-and-paper-based observational methods in assessing ergonomic risk factors of computer work. We searched an electronic database for materials from 1992 until 2015. The selected methods were focused on computer work, pen-and-paper observational methods, office risk factors and musculoskeletal disorders. This review was developed to assess the risk factors, reliability and validity of pen-and-paper observational method associated with computer work. Two evaluators independently carried out this review. Seven observational methods used to assess exposure to office risk factor for work-related musculoskeletal disorders were identified. The risk factors involved in current techniques of pen and paper based observational tools were postures, office components, force and repetition. From the seven methods, only five methods had been tested for reliability. They were proven to be reliable and were rated as moderate to good. For the validity testing, from seven methods only four methods were tested and the results are moderate. Many observational tools already exist, but no single tool appears to cover all of the risk factors including working posture, office component, force, repetition and office environment at office workstations and computer work. Although the most important factor in developing tool is proper validation of exposure assessment techniques, the existing observational method did not test reliability and validity. Futhermore, this review could provide the researchers with ways on how to improve the pen-and-paper-based observational method for assessing ergonomic risk factors of computer work.

Wise Crowd Content Assessment and Educational Rubrics

ERIC Educational Resources Information Center

Passonneau, Rebecca J.; Poddar, Ananya; Gite, Gaurav; Krivokapic, Alisa; Yang, Qian; Perin, Dolores

2018-01-01

Development of reliable rubrics for educational intervention studies that address reading and writing skills is labor-intensive, and could benefit from an automated approach. We compare a main ideas rubric used in a successful writing intervention study to a highly reliable wise-crowd content assessment method developed to evaluate…

Covariate-free and Covariate-dependent Reliability.

PubMed

Bentler, Peter M

2016-12-01

Classical test theory reliability coefficients are said to be population specific. Reliability generalization, a meta-analysis method, is the main procedure for evaluating the stability of reliability coefficients across populations. A new approach is developed to evaluate the degree of invariance of reliability coefficients to population characteristics. Factor or common variance of a reliability measure is partitioned into parts that are, and are not, influenced by control variables, resulting in a partition of reliability into a covariate-dependent and a covariate-free part. The approach can be implemented in a single sample and can be applied to a variety of reliability coefficients.

Multi-criteria decision making development of ion chromatographic method for determination of inorganic anions in oilfield waters based on artificial neural networks retention model.

PubMed

Stefanović, Stefica Cerjan; Bolanča, Tomislav; Luša, Melita; Ukić, Sime; Rogošić, Marko

2012-02-24

This paper describes the development of ad hoc methodology for determination of inorganic anions in oilfield water, since their composition often significantly differs from the average (concentration of components and/or matrix). Therefore, fast and reliable method development has to be performed in order to ensure the monitoring of desired properties under new conditions. The method development was based on computer assisted multi-criteria decision making strategy. The used criteria were: maximal value of objective functions used, maximal robustness of the separation method, minimal analysis time, and maximal retention distance between two nearest components. Artificial neural networks were used for modeling of anion retention. The reliability of developed method was extensively tested by the validation of performance characteristics. Based on validation results, the developed method shows satisfactory performance characteristics, proving the successful application of computer assisted methodology in the described case study. Copyright © 2011 Elsevier B.V. All rights reserved.

Structural Optimization for Reliability Using Nonlinear Goal Programming

NASA Technical Reports Server (NTRS)

El-Sayed, Mohamed E.

1999-01-01

This report details the development of a reliability based multi-objective design tool for solving structural optimization problems. Based on two different optimization techniques, namely sequential unconstrained minimization and nonlinear goal programming, the developed design method has the capability to take into account the effects of variability on the proposed design through a user specified reliability design criterion. In its sequential unconstrained minimization mode, the developed design tool uses a composite objective function, in conjunction with weight ordered design objectives, in order to take into account conflicting and multiple design criteria. Multiple design criteria of interest including structural weight, load induced stress and deflection, and mechanical reliability. The nonlinear goal programming mode, on the other hand, provides for a design method that eliminates the difficulty of having to define an objective function and constraints, while at the same time has the capability of handling rank ordered design objectives or goals. For simulation purposes the design of a pressure vessel cover plate was undertaken as a test bed for the newly developed design tool. The formulation of this structural optimization problem into sequential unconstrained minimization and goal programming form is presented. The resulting optimization problem was solved using: (i) the linear extended interior penalty function method algorithm; and (ii) Powell's conjugate directions method. Both single and multi-objective numerical test cases are included demonstrating the design tool's capabilities as it applies to this design problem.

The Development of DNA Based Methods for the Reliable and Efficient Identification of Nicotiana tabacum in Tobacco and Its Derived Products

PubMed Central

Fan, Wei; Li, Rong; Li, Sifan; Ping, Wenli; Li, Shujun; Naumova, Alexandra; Peelen, Tamara; Yuan, Zheng; Zhang, Dabing

2016-01-01

Reliable methods are needed to detect the presence of tobacco components in tobacco products to effectively control smuggling and classify tariff and excise in tobacco industry to control illegal tobacco trade. In this study, two sensitive and specific DNA based methods, one quantitative real-time PCR (qPCR) assay and the other loop-mediated isothermal amplification (LAMP) assay, were developed for the reliable and efficient detection of the presence of tobacco (Nicotiana tabacum) in various tobacco samples and commodities. Both assays targeted the same sequence of the uridine 5′-monophosphate synthase (UMPS), and their specificities and sensitivities were determined with various plant materials. Both qPCR and LAMP methods were reliable and accurate in the rapid detection of tobacco components in various practical samples, including customs samples, reconstituted tobacco samples, and locally purchased cigarettes, showing high potential for their application in tobacco identification, particularly in the special cases where the morphology or chemical compositions of tobacco have been disrupted. Therefore, combining both methods would facilitate not only the detection of tobacco smuggling control, but also the detection of tariff classification and of excise. PMID:27635142

Evaluating the Performance of the IEEE Standard 1366 Method for Identifying Major Event Days

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

Eto, Joseph H.; LaCommare, Kristina Hamachi; Sohn, Michael D.

IEEE Standard 1366 offers a method for segmenting reliability performance data to isolate the effects of major events from the underlying year-to-year trends in reliability. Recent analysis by the IEEE Distribution Reliability Working Group (DRWG) has found that reliability performance of some utilities differs from the expectations that helped guide the development of the Standard 1366 method. This paper proposes quantitative metrics to evaluate the performance of the Standard 1366 method in identifying major events and in reducing year-to-year variability in utility reliability. The metrics are applied to a large sample of utility-reported reliability data to assess performance of themore » method with alternative specifications that have been considered by the DRWG. We find that none of the alternatives perform uniformly 'better' than the current Standard 1366 method. That is, none of the modifications uniformly lowers the year-to-year variability in System Average Interruption Duration Index without major events. Instead, for any given alternative, while it may lower the value of this metric for some utilities, it also increases it for other utilities (sometimes dramatically). Thus, we illustrate some of the trade-offs that must be considered in using the Standard 1366 method and highlight the usefulness of the metrics we have proposed in conducting these evaluations.« less

Methods for assessing reliability and validity for a measurement tool: a case study and critique using the WHO haemoglobin colour scale.

PubMed

White, Sarah A; van den Broek, Nynke R

2004-05-30

Before introducing a new measurement tool it is necessary to evaluate its performance. Several statistical methods have been developed, or used, to evaluate the reliability and validity of a new assessment method in such circumstances. In this paper we review some commonly used methods. Data from a study that was conducted to evaluate the usefulness of a specific measurement tool (the WHO Colour Scale) is then used to illustrate the application of these methods. The WHO Colour Scale was developed under the auspices of the WHO to provide a simple portable and reliable method of detecting anaemia. This Colour Scale is a discrete interval scale, whereas the actual haemoglobin values it is used to estimate are on a continuous interval scale and can be measured accurately using electrical laboratory equipment. The methods we consider are: linear regression, correlation coefficients, paired t-tests plotting differences against mean values and deriving limits of agreement; kappa and weighted kappa statistics, sensitivity and specificity, an intraclass correlation coefficient and the repeatability coefficient. We note that although the definition and properties of each of these methods is well established inappropriate methods continue to be used in medical literature for assessing reliability and validity, as evidenced in the context of the evaluation of the WHO Colour Scale. Copyright 2004 John Wiley & Sons, Ltd.

Development of Creative Behavior Observation Form: A Study on Validity and Reliability

ERIC Educational Resources Information Center

Dere, Zeynep; Ömeroglu, Esra

2018-01-01

This study, Creative Behavior Observation Form was developed to assess creativity of the children. While the study group on the reliability and validity of Creative Behavior Observation Form was being developed, 257 children in total who were at the ages of 5-6 were used as samples with stratified sampling method. Content Validity Index (CVI) and…

Development of a method for measuring femoral torsion using real-time ultrasound.

PubMed

Hafiz, Eliza; Hiller, Claire E; Nicholson, Leslie L; Nightingale, E Jean; Clarke, Jillian L; Grimaldi, Alison; Eisenhuth, John P; Refshauge, Kathryn M

2014-07-01

Excessive femoral torsion has been associated with various musculoskeletal and neurological problems. To explore this relationship, it is essential to be able to measure femoral torsion in the clinic accurately. Computerized tomography (CT) and magnetic resonance imaging (MRI) are thought to provide the most accurate measurements but CT involves significant radiation exposure and MRI is expensive. The aim of this study was to design a method for measuring femoral torsion in the clinic, and to determine the reliability of this method. Details of design process, including construction of a jig, the protocol developed and the reliability of the method are presented. The protocol developed used ultrasound to image a ridge on the greater trochanter, and a customized jig placed on the femoral condyles as reference points. An inclinometer attached to the customized jig allowed quantification of the degree of femoral torsion. Measurements taken with this protocol had excellent intra- and inter-rater reliability (ICC2,1 = 0.98 and 0.97, respectively). This method of measuring femoral torsion also permitted measurement of femoral torsion with a high degree of accuracy. This method is applicable to the research setting and, with minor adjustments, will be applicable to the clinical setting.

Modeling of unit operating considerations in generating-capacity reliability evaluation. Volume 1. Mathematical models, computing methods, and results. Final report. [GENESIS, OPCON and OPPLAN

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

Patton, A.D.; Ayoub, A.K.; Singh, C.

1982-07-01

Existing methods for generating capacity reliability evaluation do not explicitly recognize a number of operating considerations which may have important effects in system reliability performance. Thus, current methods may yield estimates of system reliability which differ appreciably from actual observed reliability. Further, current methods offer no means of accurately studying or evaluating alternatives which may differ in one or more operating considerations. Operating considerations which are considered to be important in generating capacity reliability evaluation include: unit duty cycles as influenced by load cycle shape, reliability performance of other units, unit commitment policy, and operating reserve policy; unit start-up failuresmore » distinct from unit running failures; unit start-up times; and unit outage postponability and the management of postponable outages. A detailed Monte Carlo simulation computer model called GENESIS and two analytical models called OPCON and OPPLAN have been developed which are capable of incorporating the effects of many operating considerations including those noted above. These computer models have been used to study a variety of actual and synthetic systems and are available from EPRI. The new models are shown to produce system reliability indices which differ appreciably from index values computed using traditional models which do not recognize operating considerations.« less

Reliability design and verification for launch-vehicle propulsion systems - Report of an AIAA Workshop, Washington, DC, May 16, 17, 1989

NASA Astrophysics Data System (ADS)

Launch vehicle propulsion system reliability considerations during the design and verification processes are discussed. The tools available for predicting and minimizing anomalies or failure modes are described and objectives for validating advanced launch system propulsion reliability are listed. Methods for ensuring vehicle/propulsion system interface reliability are examined and improvements in the propulsion system development process are suggested to improve reliability in launch operations. Also, possible approaches to streamline the specification and procurement process are given. It is suggested that government and industry should define reliability program requirements and manage production and operations activities in a manner that provides control over reliability drivers. Also, it is recommended that sufficient funds should be invested in design, development, test, and evaluation processes to ensure that reliability is not inappropriately subordinated to other management considerations.

The Healthcare Complaints Analysis Tool: development and reliability testing of a method for service monitoring and organisational learning

PubMed Central

Gillespie, Alex; Reader, Tom W

2016-01-01

Background Letters of complaint written by patients and their advocates reporting poor healthcare experiences represent an under-used data source. The lack of a method for extracting reliable data from these heterogeneous letters hinders their use for monitoring and learning. To address this gap, we report on the development and reliability testing of the Healthcare Complaints Analysis Tool (HCAT). Methods HCAT was developed from a taxonomy of healthcare complaints reported in a previously published systematic review. It introduces the novel idea that complaints should be analysed in terms of severity. Recruiting three groups of educated lay participants (n=58, n=58, n=55), we refined the taxonomy through three iterations of discriminant content validity testing. We then supplemented this refined taxonomy with explicit coding procedures for seven problem categories (each with four levels of severity), stage of care and harm. These combined elements were further refined through iterative coding of a UK national sample of healthcare complaints (n= 25, n=80, n=137, n=839). To assess reliability and accuracy for the resultant tool, 14 educated lay participants coded a referent sample of 125 healthcare complaints. Results The seven HCAT problem categories (quality, safety, environment, institutional processes, listening, communication, and respect and patient rights) were found to be conceptually distinct. On average, raters identified 1.94 problems (SD=0.26) per complaint letter. Coders exhibited substantial reliability in identifying problems at four levels of severity; moderate and substantial reliability in identifying stages of care (except for ‘discharge/transfer’ that was only fairly reliable) and substantial reliability in identifying overall harm. Conclusions HCAT is not only the first reliable tool for coding complaints, it is the first tool to measure the severity of complaints. It facilitates service monitoring and organisational learning and it enables future research examining whether healthcare complaints are a leading indicator of poor service outcomes. HCAT is freely available to download and use. PMID:26740496

Tackling reliability and construct validity: the systematic development of a qualitative protocol for skill and incident analysis.

PubMed

Savage, Trevor Nicholas; McIntosh, Andrew Stuart

2017-03-01

It is important to understand factors contributing to and directly causing sports injuries to improve the effectiveness and safety of sports skills. The characteristics of injury events must be evaluated and described meaningfully and reliably. However, many complex skills cannot be effectively investigated quantitatively because of ethical, technological and validity considerations. Increasingly, qualitative methods are being used to investigate human movement for research purposes, but there are concerns about reliability and measurement bias of such methods. Using the tackle in Rugby union as an example, we outline a systematic approach for developing a skill analysis protocol with a focus on improving objectivity, validity and reliability. Characteristics for analysis were selected using qualitative analysis and biomechanical theoretical models and epidemiological and coaching literature. An expert panel comprising subject matter experts provided feedback and the inter-rater reliability of the protocol was assessed using ten trained raters. The inter-rater reliability results were reviewed by the expert panel and the protocol was revised and assessed in a second inter-rater reliability study. Mean agreement in the second study improved and was comparable (52-90% agreement and ICC between 0.6 and 0.9) with other studies that have reported inter-rater reliability of qualitative analysis of human movement.

Japanese Adaptation of the Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39): Comparative Study among Different Types of Aphasia.

PubMed

Kamiya, Akane; Kamiya, Kentaro; Tatsumi, Hiroshi; Suzuki, Makihiko; Horiguchi, Satoshi

2015-11-01

We have developed a Japanese version of the Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39), designated as SAQOL-39-J, and used psychometric methods to examine its acceptability and reliability. The acceptability and reliability of SAQOL-39-J, which was developed from the English version using a standard translation and back-translation method, were examined in 54 aphasia patients using standard psychometric methods. The acceptability and reliability of SAQOL-39-J were then compared among patients with different types of aphasia. SAQOL-39-J showed good acceptability, internal consistency (Cronbach's α score = .90), and test-retest reliability (intraclass correlation coefficient = .97). Broca's aphasia patients showed the lowest total scores and communication scores on SAQOL-39-J. The Japanese version of SAQOL-39, SAQOL-39-J, provides acceptable and reliable data in Japanese stroke patients with aphasia. Among different types of aphasia, Broca's aphasia patients had the lowest total and communication SAQOL-39-J scores. Further studies are needed to assess the effectiveness of health care interventions on health-related quality of life in this population. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Overview of RICOR's reliability theoretical analysis, accelerated life demonstration test results and verification by field data

NASA Astrophysics Data System (ADS)

Vainshtein, Igor; Baruch, Shlomi; Regev, Itai; Segal, Victor; Filis, Avishai; Riabzev, Sergey

2018-05-01

The growing demand for EO applications that work around the clock 24hr/7days a week, such as in border surveillance systems, emphasizes the need for a highly reliable cryocooler having increased operational availability and optimized system's Integrated Logistic Support (ILS). In order to meet this need, RICOR developed linear and rotary cryocoolers which achieved successfully this goal. Cryocoolers MTTF was analyzed by theoretical reliability evaluation methods, demonstrated by normal and accelerated life tests at Cryocooler level and finally verified by field data analysis derived from Cryocoolers operating at system level. The following paper reviews theoretical reliability analysis methods together with analyzing reliability test results derived from standard and accelerated life demonstration tests performed at Ricor's advanced reliability laboratory. As a summary for the work process, reliability verification data will be presented as a feedback from fielded systems.

Reliability evaluation of microgrid considering incentive-based demand response

NASA Astrophysics Data System (ADS)

Huang, Ting-Cheng; Zhang, Yong-Jun

2017-07-01

Incentive-based demand response (IBDR) can guide customers to adjust their behaviour of electricity and curtail load actively. Meanwhile, distributed generation (DG) and energy storage system (ESS) can provide time for the implementation of IBDR. The paper focus on the reliability evaluation of microgrid considering IBDR. Firstly, the mechanism of IBDR and its impact on power supply reliability are analysed. Secondly, the IBDR dispatch model considering customer’s comprehensive assessment and the customer response model are developed. Thirdly, the reliability evaluation method considering IBDR based on Monte Carlo simulation is proposed. Finally, the validity of the above models and method is studied through numerical tests on modified RBTS Bus6 test system. Simulation results demonstrated that IBDR can improve the reliability of microgrid.

Acromiohumeral distance measurement in rotator cuff tendinopathy: is there a reliable, clinically applicable method? A systematic review.

PubMed

McCreesh, Karen M; Crotty, James M; Lewis, Jeremy S

2015-03-01

Narrowing of the subacromial space has been noted as a common feature of rotator cuff (RC) tendinopathy. It has been implicated in the development of symptoms and forms the basis for some surgical and rehabilitation approaches. Various radiological methods have been used to measure the subacromial space, which is represented by a two-dimensional measurement of acromiohumeral distance (AHD). A reliable method of measurement could be used to assess the impact of rehabilitation or surgical interventions for RC tendinopathy; however, there are no published reviews assessing the reliability of AHD measurement. The aim of this review was to systematically assess the evidence for the intrarater and inter-rater reliability of radiological methods of measuring AHD, in order to identify the most reliable method for use in RC tendinopathy. An electronic literature search was carried out and studies describing the reliability of any radiological method of measuring AHD in either healthy or RC tendinopathy groups were included. Eighteen studies met the inclusion criteria and were appraised by two reviewers using the Quality Appraisal for reliability Studies checklist. Eight studies were deemed to be of high methodological quality. Study weaknesses included lack of tester blinding, inadequate description of tester experience, lack of inclusion of symptomatic populations, poor reporting of statistical methods and unclear diagnosis. There was strong evidence for the reliability of ultrasound for measuring AHD, with moderate evidence for MRI and CT measures and conflicting evidence for radiographic methods. Overall, there was lack of research in RC tendinopathy populations, with only six studies including participants with shoulder pain. The results support the reliability of ultrasound and CT or MRI for the measurement of AHD; however, more studies in symptomatic populations are required. The reliability of AHD measurement using radiographs has not been supported by the studies reviewed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Survey of Software Assurance Techniques for Highly Reliable Systems

NASA Technical Reports Server (NTRS)

Nelson, Stacy

2004-01-01

This document provides a survey of software assurance techniques for highly reliable systems including a discussion of relevant safety standards for various industries in the United States and Europe, as well as examples of methods used during software development projects. It contains one section for each industry surveyed: Aerospace, Defense, Nuclear Power, Medical Devices and Transportation. Each section provides an overview of applicable standards and examples of a mission or software development project, software assurance techniques used and reliability achieved.

Interval Estimation of Revision Effect on Scale Reliability via Covariance Structure Modeling

ERIC Educational Resources Information Center

Raykov, Tenko

2009-01-01

A didactic discussion of a procedure for interval estimation of change in scale reliability due to revision is provided, which is developed within the framework of covariance structure modeling. The method yields ranges of plausible values for the population gain or loss in reliability of unidimensional composites, which results from deletion or…

Assessment and risk classification protocol for patients in emergency units1

PubMed Central

Silva, Michele de Freitas Neves; Oliveira, Gabriela Novelli; Pergola-Marconato, Aline Maino; Marconato, Rafael Silva; Bargas, Eliete Boaventura; Araujo, Izilda Esmenia Muglia

2014-01-01

Objective to develop, validate the contents and verify the reliability of a risk classification protocol for an Emergency Unit. Method the content validation was developed in a University Hospital in a country town located in the state of Sao Paulo and was carried out in two stages: the first with the individual assessment of specialists and the second with the meeting between the researchers and the specialists. The use of the protocol followed a specific guide. Concerning reliability, the concordance or equivalent method among observers was used. Results the protocol developed showed to have content validity and, after the suggested changes were made, there were excellent results concerning reliability. Conclusion the assistance flow chart was shown to be easy to use, and facilitate the search for the complaint in each assistance priority. PMID:26107828

Reliability based fatigue design and maintenance procedures

NASA Technical Reports Server (NTRS)

Hanagud, S.

1977-01-01

A stochastic model has been developed to describe a probability for fatigue process by assuming a varying hazard rate. This stochastic model can be used to obtain the desired probability of a crack of certain length at a given location after a certain number of cycles or time. Quantitative estimation of the developed model was also discussed. Application of the model to develop a procedure for reliability-based cost-effective fail-safe structural design is presented. This design procedure includes the reliability improvement due to inspection and repair. Methods of obtaining optimum inspection and maintenance schemes are treated.

Models for evaluating the performability of degradable computing systems

NASA Technical Reports Server (NTRS)

Wu, L. T.

1982-01-01

Recent advances in multiprocessor technology established the need for unified methods to evaluate computing systems performance and reliability. In response to this modeling need, a general modeling framework that permits the modeling, analysis and evaluation of degradable computing systems is considered. Within this framework, several user oriented performance variables are identified and shown to be proper generalizations of the traditional notions of system performance and reliability. Furthermore, a time varying version of the model is developed to generalize the traditional fault tree reliability evaluation methods of phased missions.

A reliability design method for a lithium-ion battery pack considering the thermal disequilibrium in electric vehicles

NASA Astrophysics Data System (ADS)

Xia, Quan; Wang, Zili; Ren, Yi; Sun, Bo; Yang, Dezhen; Feng, Qiang

2018-05-01

With the rapid development of lithium-ion battery technology in the electric vehicle (EV) industry, the lifetime of the battery cell increases substantially; however, the reliability of the battery pack is still inadequate. Because of the complexity of the battery pack, a reliability design method for a lithium-ion battery pack considering the thermal disequilibrium is proposed in this paper based on cell redundancy. Based on this method, a three-dimensional electric-thermal-flow-coupled model, a stochastic degradation model of cells under field dynamic conditions and a multi-state system reliability model of a battery pack are established. The relationships between the multi-physics coupling model, the degradation model and the system reliability model are first constructed to analyze the reliability of the battery pack and followed by analysis examples with different redundancy strategies. By comparing the reliability of battery packs of different redundant cell numbers and configurations, several conclusions for the redundancy strategy are obtained. More notably, the reliability does not monotonically increase with the number of redundant cells for the thermal disequilibrium effects. In this work, the reliability of a 6 × 5 parallel-series configuration is the optimal system structure. In addition, the effect of the cell arrangement and cooling conditions are investigated.

A research coding method for the basic patient-centered interview.

PubMed

Grayson-Sneed, Katelyn A; Smith, Sandi W; Smith, Robert C

2017-03-01

To develop a more reliable coding method of medical interviewing focused on data-gathering and emotion-handling. Two trained (30h) undergraduates rated videotaped interviews from 127 resident-simulated patient (SP) interactions. Trained on 45 videotapes, raters coded 25 of 127 study set tapes for patient-centeredness. Guetzkow's U, Cohen's Kappa, and percent of agreement were used to measure raters' reliability in unitizing and coding residents' skills for eliciting: agenda (3 yes/no items), physical story (2), personal story (6), emotional story (15), using indirect skills (4), and general patient-centeredness (3). 45 items were dichotomized from the earlier, Likert scale-based method and were reduced to 33 during training. Guetzkow's U ranged from 0.00 to 0.087. Kappa ranged from 0.86 to 1.00 for the 6 variables and 33 individual items. The overall kappa was 0.90, and percent of agreement was 97.5%. Percent of agreement by item ranged from 84 to 100%. A simple, highly reliable coding method, weighted (by no. of items) to highlight personal elements of an interview, was developed and is recommended as a criterion standard research coding method. An easily conducted, reliable coding procedure can be the basis for everyday questionnaires like patient satisfaction with patient-centeredness. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A Statistical Testing Approach for Quantifying Software Reliability; Application to an Example System

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

Chu, Tsong-Lun; Varuttamaseni, Athi; Baek, Joo-Seok

The U.S. Nuclear Regulatory Commission (NRC) encourages the use of probabilistic risk assessment (PRA) technology in all regulatory matters, to the extent supported by the state-of-the-art in PRA methods and data. Although much has been accomplished in the area of risk-informed regulation, risk assessment for digital systems has not been fully developed. The NRC established a plan for research on digital systems to identify and develop methods, analytical tools, and regulatory guidance for (1) including models of digital systems in the PRAs of nuclear power plants (NPPs), and (2) incorporating digital systems in the NRC's risk-informed licensing and oversight activities.more » Under NRC's sponsorship, Brookhaven National Laboratory (BNL) explored approaches for addressing the failures of digital instrumentation and control (I and C) systems in the current NPP PRA framework. Specific areas investigated included PRA modeling digital hardware, development of a philosophical basis for defining software failure, and identification of desirable attributes of quantitative software reliability methods. Based on the earlier research, statistical testing is considered a promising method for quantifying software reliability. This paper describes a statistical software testing approach for quantifying software reliability and applies it to the loop-operating control system (LOCS) of an experimental loop of the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL).« less

The Language Use Inventory for Young Children: A Parent-Report Measure of Pragmatic Language Development for 18- to 47-Month-Old Children

ERIC Educational Resources Information Center

O'Neill, Daniela K.

2007-01-01

Purpose: To demonstrate the internal reliability and discriminative validity of the Language Use Inventory for Young Children (LUI; D. K. O'Neill, 2002), a newly developed parent-report measure designed to assess pragmatic language development in 18-47-month-olds. Method: To examine internal reliability, the LUI was completed by mail by 177…

Historical Development of Asphalt Content Determination by the Ignition Method

DOT National Transportation Integrated Search

1996-01-01

This study was conducted to develop a reliable, detailed test procedure for determining asphalt cement (AC) content by the ignition method. The goal was to minimize the overall test time as well as technician time, and to produce a test method with a...

Reliability and risk assessment of structures

NASA Technical Reports Server (NTRS)

Chamis, C. C.

1991-01-01

Development of reliability and risk assessment of structural components and structures is a major activity at Lewis Research Center. It consists of five program elements: (1) probabilistic loads; (2) probabilistic finite element analysis; (3) probabilistic material behavior; (4) assessment of reliability and risk; and (5) probabilistic structural performance evaluation. Recent progress includes: (1) the evaluation of the various uncertainties in terms of cumulative distribution functions for various structural response variables based on known or assumed uncertainties in primitive structural variables; (2) evaluation of the failure probability; (3) reliability and risk-cost assessment; and (4) an outline of an emerging approach for eventual certification of man-rated structures by computational methods. Collectively, the results demonstrate that the structural durability/reliability of man-rated structural components and structures can be effectively evaluated by using formal probabilistic methods.

Reliable volumetry of the cervical spinal cord in MS patient follow-up data with cord image analyzer (Cordial).

PubMed

Amann, Michael; Pezold, Simon; Naegelin, Yvonne; Fundana, Ketut; Andělová, Michaela; Weier, Katrin; Stippich, Christoph; Kappos, Ludwig; Radue, Ernst-Wilhelm; Cattin, Philippe; Sprenger, Till

2016-07-01

Spinal cord (SC) atrophy is an important contributor to the development of disability in many neurological disorders including multiple sclerosis (MS). To assess the spinal cord atrophy in clinical trials and clinical practice, largely automated methods are needed due to the sheer amount of data. Moreover, using these methods in longitudinal trials requires them to deliver highly reliable measurements, enabling comparisons of multiple data sets of the same subject over time. We present a method for SC volumetry using 3D MRI data providing volume measurements for SC sections of fixed length and location. The segmentation combines a continuous max flow approach with SC surface reconstruction that locates the SC boundary based on image voxel intensities. Two cutting planes perpendicular to the SC centerline are determined based on predefined distances to an anatomical landmark, and the cervical SC volume (CSCV) is then calculated in-between these boundaries. The development of the method focused on its application in MRI follow-up studies; the method provides a high scan-rescan reliability, which was tested on healthy subject data. Scan-rescan reliability coefficients of variation (COV) were below 1 %, intra- and interrater COV were even lower (0.1-0.2 %). To show the applicability in longitudinal trials, 3-year follow-up data of 48 patients with a progressive course of MS were assessed. In this cohort, CSCV loss was the only significant predictor of disability progression (p = 0.02). We are, therefore, confident that our method provides a reliable tool for SC volumetry in longitudinal clinical trials.

Recent developments of the NESSUS probabilistic structural analysis computer program

NASA Technical Reports Server (NTRS)

Millwater, H.; Wu, Y.-T.; Torng, T.; Thacker, B.; Riha, D.; Leung, C. P.

1992-01-01

The NESSUS probabilistic structural analysis computer program combines state-of-the-art probabilistic algorithms with general purpose structural analysis methods to compute the probabilistic response and the reliability of engineering structures. Uncertainty in loading, material properties, geometry, boundary conditions and initial conditions can be simulated. The structural analysis methods include nonlinear finite element and boundary element methods. Several probabilistic algorithms are available such as the advanced mean value method and the adaptive importance sampling method. The scope of the code has recently been expanded to include probabilistic life and fatigue prediction of structures in terms of component and system reliability and risk analysis of structures considering cost of failure. The code is currently being extended to structural reliability considering progressive crack propagation. Several examples are presented to demonstrate the new capabilities.

Comparative Analysis of the Reliability of Steel Structure with Pinned and Rigid Nodes Subjected to Fire

NASA Astrophysics Data System (ADS)

Kubicka, Katarzyna; Radoń, Urszula; Szaniec, Waldemar; Pawlak, Urszula

2017-10-01

The paper concerns the reliability analysis of steel structures subjected to high temperatures of fire gases. Two types of spatial structures were analysed, namely with pinned and rigid nodes. The fire analysis was carried out according to prescriptions of Eurocode. The static-strength analysis was conducted using the finite element method (FEM). The MES3D program, developed by Szaniec (Kielce University of Technology, Poland), was used for this purpose. The results received from MES3D made it possible to carry out the reliability analysis using the Numpress Explore program that was developed at the Institute of Fundamental Technological Research of the Polish Academy of Sciences [9]. The measurement of reliability of structures is the Hasofer-Lind reliability index (β). The reliability analysis was carried out according to approximation (FORM, SORM) and simulation (Importance Sampling, Monte Carlo) methods. As the fire progresses, the value of reliability index decreases. The analysis conducted for the study made it possible to evaluate the impact of node types on those changes. In real structures, it is often difficult to define correctly types of nodes, so some simplifications are made. The presented analysis contributes to the recognition of consequences of such assumptions for the safety of structures, subjected to fire.

Predicting Job Performance for the Visually Impaired: Validity of the Fine Finger Dexterity Work Task.

ERIC Educational Resources Information Center

Giesen, J. Martin; And Others

The study was designed to determine the reliability and criterion validity of a psychomotor performance test (the Fine Finger Dexterity Work Task Unit) with 40 partially or totally blind adults. Reliability was established by using the test-retest method. A supervisory rating was developed and the reliability established by using the split-half…

Assessment of a condition-specific quality-of-life measure for patients with developmentally absent teeth: validity and reliability testing.

PubMed

Akram, A J; Ireland, A J; Postlethwaite, K C; Sandy, J R; Jerreat, A S

2013-11-01

This article describes the process of validity and reliability testing of a condition-specific quality-of-life measure for patients with hypodontia presenting for orthodontic treatment. The development of the instrument is described in a previous article. Royal Devon and Exeter NHS Foundation Trust & Musgrove Park Hospital, Taunton. The child perception questionnaire was used as a standard against which to test criterion validity. The Bland and Altman method was used to check agreement between the two questionnaires. Construct validity was tested using principal component analysis on the four sections of the questionnaire. Test-retest reliability was tested using intraclass correlation coefficient and Bland and Altman method. Cronbach's alpha was used to test internal consistency reliability. Overall the questionnaire showed good reliability, criterion and construct validity. This together with previous evidence of good face and content validity suggests that the instrument may prove useful in clinical practice and further research. This study has demonstrated that the newly developed condition-specific quality-of-life questionnaire is both valid and reliable for use in young patients with hypodontia. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Software reliability perspectives

NASA Technical Reports Server (NTRS)

Wilson, Larry; Shen, Wenhui

1987-01-01

Software which is used in life critical functions must be known to be highly reliable before installation. This requires a strong testing program to estimate the reliability, since neither formal methods, software engineering nor fault tolerant methods can guarantee perfection. Prior to the final testing software goes through a debugging period and many models have been developed to try to estimate reliability from the debugging data. However, the existing models are poorly validated and often give poor performance. This paper emphasizes the fact that part of their failures can be attributed to the random nature of the debugging data given to these models as input, and it poses the problem of correcting this defect as an area of future research.

Probabilistic fatigue methodology for six nines reliability

NASA Technical Reports Server (NTRS)

Everett, R. A., Jr.; Bartlett, F. D., Jr.; Elber, Wolf

1990-01-01

Fleet readiness and flight safety strongly depend on the degree of reliability that can be designed into rotorcraft flight critical components. The current U.S. Army fatigue life specification for new rotorcraft is the so-called six nines reliability, or a probability of failure of one in a million. The progress of a round robin which was established by the American Helicopter Society (AHS) Subcommittee for Fatigue and Damage Tolerance is reviewed to investigate reliability-based fatigue methodology. The participants in this cooperative effort are in the U.S. Army Aviation Systems Command (AVSCOM) and the rotorcraft industry. One phase of the joint activity examined fatigue reliability under uniquely defined conditions for which only one answer was correct. The other phases were set up to learn how the different industry methods in defining fatigue strength affected the mean fatigue life and reliability calculations. Hence, constant amplitude and spectrum fatigue test data were provided so that each participant could perform their standard fatigue life analysis. As a result of this round robin, the probabilistic logic which includes both fatigue strength and spectrum loading variability in developing a consistant reliability analysis was established. In this first study, the reliability analysis was limited to the linear cumulative damage approach. However, it is expected that superior fatigue life prediction methods will ultimately be developed through this open AHS forum. To that end, these preliminary results were useful in identifying some topics for additional study.

Developing Sustainable Life Support System Concepts

NASA Technical Reports Server (NTRS)

Thomas, Evan A.

2010-01-01

Sustainable spacecraft life support concepts may allow the development of more reliable technologies for long duration space missions. Currently, life support technologies at different levels of development are not well evaluated against each other, and evaluation methods do not account for long term reliability and sustainability of the hardware. This paper presents point-of-departure sustainability evaluation criteria for life support systems, that may allow more robust technology development, testing and comparison. An example sustainable water recovery system concept is presented.

Hierarchical modeling for reliability analysis using Markov models. B.S./M.S. Thesis - MIT

NASA Technical Reports Server (NTRS)

Fagundo, Arturo

1994-01-01

Markov models represent an extremely attractive tool for the reliability analysis of many systems. However, Markov model state space grows exponentially with the number of components in a given system. Thus, for very large systems Markov modeling techniques alone become intractable in both memory and CPU time. Often a particular subsystem can be found within some larger system where the dependence of the larger system on the subsystem is of a particularly simple form. This simple dependence can be used to decompose such a system into one or more subsystems. A hierarchical technique is presented which can be used to evaluate these subsystems in such a way that their reliabilities can be combined to obtain the reliability for the full system. This hierarchical approach is unique in that it allows the subsystem model to pass multiple aggregate state information to the higher level model, allowing more general systems to be evaluated. Guidelines are developed to assist in the system decomposition. An appropriate method for determining subsystem reliability is also developed. This method gives rise to some interesting numerical issues. Numerical error due to roundoff and integration are discussed at length. Once a decomposition is chosen, the remaining analysis is straightforward but tedious. However, an approach is developed for simplifying the recombination of subsystem reliabilities. Finally, a real world system is used to illustrate the use of this technique in a more practical context.

Overview of the SAE G-11 RMSL (Reliability, Maintainability, Supportability, and Logistics) Division Activities and Technical Projects

NASA Technical Reports Server (NTRS)

Singhal, Surendra N.

2003-01-01

The SAE G-11 RMSL (Reliability, Maintainability, Supportability, and Logistics) Division activities include identification and fulfillment of joint industry, government, and academia needs for development and implementation of RMSL technologies. Four Projects in the Probabilistic Methods area and two in the area of RMSL have been identified. These are: (1) Evaluation of Probabilistic Technology - progress has been made toward the selection of probabilistic application cases. Future effort will focus on assessment of multiple probabilistic softwares in solving selected engineering problems using probabilistic methods. Relevance to Industry & Government - Case studies of typical problems encountering uncertainties, results of solutions to these problems run by different codes, and recommendations on which code is applicable for what problems; (2) Probabilistic Input Preparation - progress has been made in identifying problem cases such as those with no data, little data and sufficient data. Future effort will focus on developing guidelines for preparing input for probabilistic analysis, especially with no or little data. Relevance to Industry & Government - Too often, we get bogged down thinking we need a lot of data before we can quantify uncertainties. Not True. There are ways to do credible probabilistic analysis with little data; (3) Probabilistic Reliability - probabilistic reliability literature search has been completed along with what differentiates it from statistical reliability. Work on computation of reliability based on quantification of uncertainties in primitive variables is in progress. Relevance to Industry & Government - Correct reliability computations both at the component and system level are needed so one can design an item based on its expected usage and life span; (4) Real World Applications of Probabilistic Methods (PM) - A draft of volume 1 comprising aerospace applications has been released. Volume 2, a compilation of real world applications of probabilistic methods with essential information demonstrating application type and timehost savings by the use of probabilistic methods for generic applications is in progress. Relevance to Industry & Government - Too often, we say, 'The Proof is in the Pudding'. With help from many contributors, we hope to produce such a document. Problem is - not too many people are coming forward due to proprietary nature. So, we are asking to document only minimum information including problem description, what method used, did it result in any savings, and how much?; (5) Software Reliability - software reliability concept, program, implementation, guidelines, and standards are being documented. Relevance to Industry & Government - software reliability is a complex issue that must be understood & addressed in all facets of business in industry, government, and other institutions. We address issues, concepts, ways to implement solutions, and guidelines for maximizing software reliability; (6) Maintainability Standards - maintainability/serviceability industry standard/guidelines and industry best practices and methodologies used in performing maintainability/ serviceability tasks are being documented. Relevance to Industry & Government - Any industry or government process, project, and/or tool must be maintained and serviced to realize the life and performance it was designed for. We address issues and develop guidelines for optimum performance & life.

A medical record review for functional somatic symptoms in children.

PubMed

Rask, Charlotte Ulrikka; Borg, Carsten; Søndergaard, Charlotte; Schulz-Pedersen, Søren; Thomsen, Per Hove; Fink, Per

2010-04-01

The objectives of this study were to develop and test a systematic medical record review for functional somatic symptoms (FSSs) in paediatric patients and to estimate the inter-rater reliability of paediatricians' recognition of FSSs and their associated impairments while using this method. We developed the Medical Record Review for Functional Somatic Symptoms in Children (MRFC) for retrospective medical record review. Described symptoms were categorised as probably, definitely, or not FSSs. FSS-associated impairment was also determined. Three paediatricians performed the MRFC on the medical records of 54 children with a diagnosed, well-defined physical disease and 59 with 'symptom' diagnoses. The inter-rater reliabilities of the recognition and associated impairment of FSSs were tested on 20 of these records. The MRFC allowed identification of subgroups of children with multisymptomatic FSSs, long-term FSSs, and/or impairing FSSs. The FSS inter-rater reliability was good (combined kappa=0.69) but only fair as far as associated impairment was concerned (combined kappa=0.29). In the hands of skilled paediatricians, the MRFC is a reliable method for identifying paediatric patients with diverse types of FSSs for clinical research. However, additional information is needed for reliable judgement of impairment. The method may also prove useful in clinical practice. Copyright 2010 Elsevier Inc. All rights reserved.

Reliability Stress-Strength Models for Dependent Observations with Applications in Clinical Trials

NASA Technical Reports Server (NTRS)

Kushary, Debashis; Kulkarni, Pandurang M.

1995-01-01

We consider the applications of stress-strength models in studies involving clinical trials. When studying the effects and side effects of certain procedures (treatments), it is often the case that observations are correlated due to subject effect, repeated measurements and observing many characteristics simultaneously. We develop maximum likelihood estimator (MLE) and uniform minimum variance unbiased estimator (UMVUE) of the reliability which in clinical trial studies could be considered as the chances of increased side effects due to a particular procedure compared to another. The results developed apply to both univariate and multivariate situations. Also, for the univariate situations we develop simple to use lower confidence bounds for the reliability. Further, we consider the cases when both stress and strength constitute time dependent processes. We define the future reliability and obtain methods of constructing lower confidence bounds for this reliability. Finally, we conduct simulation studies to evaluate all the procedures developed and also to compare the MLE and the UMVUE.

A reliability analysis tool for SpaceWire network

NASA Astrophysics Data System (ADS)

Zhou, Qiang; Zhu, Longjiang; Fei, Haidong; Wang, Xingyou

2017-04-01

A SpaceWire is a standard for on-board satellite networks as the basis for future data-handling architectures. It is becoming more and more popular in space applications due to its technical advantages, including reliability, low power and fault protection, etc. High reliability is the vital issue for spacecraft. Therefore, it is very important to analyze and improve the reliability performance of the SpaceWire network. This paper deals with the problem of reliability modeling and analysis with SpaceWire network. According to the function division of distributed network, a reliability analysis method based on a task is proposed, the reliability analysis of every task can lead to the system reliability matrix, the reliability result of the network system can be deduced by integrating these entire reliability indexes in the matrix. With the method, we develop a reliability analysis tool for SpaceWire Network based on VC, where the computation schemes for reliability matrix and the multi-path-task reliability are also implemented. By using this tool, we analyze several cases on typical architectures. And the analytic results indicate that redundancy architecture has better reliability performance than basic one. In practical, the dual redundancy scheme has been adopted for some key unit, to improve the reliability index of the system or task. Finally, this reliability analysis tool will has a directive influence on both task division and topology selection in the phase of SpaceWire network system design.

Reliability and validity of a quantitative color scale to evaluate masticatory performance using color-changeable chewing gum.

PubMed

Hama, Yohei; Kanazawa, Manabu; Minakuchi, Shunsuke; Uchida, Tatsuro; Sasaki, Yoshiyuki

2014-03-19

In the present study, we developed a novel color scale for visual assessment, conforming to theoretical color changes of a gum, to evaluate masticatoryperformance; moreover, we investigated the reliability and validity of this evaluation method using the color scale. Ten participants (aged 26.30 years) with natural dentition chewed the gum at several chewing strokes. Changes in color were measured using a colorimeter, and then, linearregression expressions that represented changes in gum color were derived. The color scale was developed using these regression expressions. Thirty-two chewed gums were evaluated using colorimeter and were assessed three times using the color scale by six dentists aged 25.27 (mean, 25.8) years, six preclinical dental students aged 21.23 (mean, 22.2) years, and six elderly individuals aged 68.84 (mean, 74.0) years. The intrarater and interrater reliability of evaluations was assessed using intraclass correlation coefficients. Validity of the method compared with a colorimeter was assessed using Spearman's rank correlation coefficient. All intraclass correlation coefficients were > 0.90, and Spearman's rank-correlation coefficients were > 0.95 in all groups. These results indicated that the evaluation method of the color-changeable chewing gum using the newly developed color scale is reliable and valid.

Reliability analysis method of a solar array by using fault tree analysis and fuzzy reasoning Petri net

NASA Astrophysics Data System (ADS)

Wu, Jianing; Yan, Shaoze; Xie, Liyang

2011-12-01

To address the impact of solar array anomalies, it is important to perform analysis of the solar array reliability. This paper establishes the fault tree analysis (FTA) and fuzzy reasoning Petri net (FRPN) models of a solar array mechanical system and analyzes reliability to find mechanisms of the solar array fault. The index final truth degree (FTD) and cosine matching function (CMF) are employed to resolve the issue of how to evaluate the importance and influence of different faults. So an improvement reliability analysis method is developed by means of the sorting of FTD and CMF. An example is analyzed using the proposed method. The analysis results show that harsh thermal environment and impact caused by particles in space are the most vital causes of the solar array fault. Furthermore, other fault modes and the corresponding improvement methods are discussed. The results reported in this paper could be useful for the spacecraft designers, particularly, in the process of redesigning the solar array and scheduling its reliability growth plan.

Methods of Measurement in epidemiology: Sedentary Behaviour

PubMed Central

Atkin, Andrew J; Gorely, Trish; Clemes, Stacy A; Yates, Thomas; Edwardson, Charlotte; Brage, Soren; Salmon, Jo; Marshall, Simon J; Biddle, Stuart JH

2012-01-01

Background Research examining sedentary behaviour as a potentially independent risk factor for chronic disease morbidity and mortality has expanded rapidly in recent years. Methods We present a narrative overview of the sedentary behaviour measurement literature. Subjective and objective methods of measuring sedentary behaviour suitable for use in population-based research with children and adults are examined. The validity and reliability of each method is considered, gaps in the literature specific to each method identified and potential future directions discussed. Results To date, subjective approaches to sedentary behaviour measurement, e.g. questionnaires, have focused predominantly on TV viewing or other screen-based behaviours. Typically, such measures demonstrate moderate reliability but slight to moderate validity. Accelerometry is increasingly being used for sedentary behaviour assessments; this approach overcomes some of the limitations of subjective methods, but detection of specific postures and postural changes by this method is somewhat limited. Instruments developed specifically for the assessment of body posture have demonstrated good reliability and validity in the limited research conducted to date. Miniaturization of monitoring devices, interoperability between measurement and communication technologies and advanced analytical approaches are potential avenues for future developments in this field. Conclusions High-quality measurement is essential in all elements of sedentary behaviour epidemiology, from determining associations with health outcomes to the development and evaluation of behaviour change interventions. Sedentary behaviour measurement remains relatively under-developed, although new instruments, both objective and subjective, show considerable promise and warrant further testing. PMID:23045206

Optimization Based Efficiencies in First Order Reliability Analysis

NASA Technical Reports Server (NTRS)

Peck, Jeffrey A.; Mahadevan, Sankaran

2003-01-01

This paper develops a method for updating the gradient vector of the limit state function in reliability analysis using Broyden's rank one updating technique. In problems that use commercial code as a black box, the gradient calculations are usually done using a finite difference approach, which becomes very expensive for large system models. The proposed method replaces the finite difference gradient calculations in a standard first order reliability method (FORM) with Broyden's Quasi-Newton technique. The resulting algorithm of Broyden updates within a FORM framework (BFORM) is used to run several example problems, and the results compared to standard FORM results. It is found that BFORM typically requires fewer functional evaluations that FORM to converge to the same answer.

Development of a Peer Teaching-Assessment Program and a Peer Observation and Evaluation Tool

PubMed Central

Trujillo, Jennifer M.; Barr, Judith; Gonyeau, Michael; Van Amburgh, Jenny A.; Matthews, S. James; Qualters, Donna

2008-01-01

Objectives To develop a formalized, comprehensive, peer-driven teaching assessment program and a valid and reliable assessment tool. Methods A volunteer taskforce was formed and a peer-assessment program was developed using a multistep, sequential approach and the Peer Observation and Evaluation Tool (POET). A pilot study was conducted to evaluate the efficiency and practicality of the process and to establish interrater reliability of the tool. Intra-class correlation coefficients (ICC) were calculated. Results ICCs for 8 separate lectures evaluated by 2-3 observers ranged from 0.66 to 0.97, indicating good interrater reliability of the tool. Conclusion Our peer assessment program for large classroom teaching, which includes a valid and reliable evaluation tool, is comprehensive, feasible, and can be adopted by other schools of pharmacy. PMID:19325963

Practical Issues in Implementing Software Reliability Measurement

NASA Technical Reports Server (NTRS)

Nikora, Allen P.; Schneidewind, Norman F.; Everett, William W.; Munson, John C.; Vouk, Mladen A.; Musa, John D.

1999-01-01

Many ways of estimating software systems' reliability, or reliability-related quantities, have been developed over the past several years. Of particular interest are methods that can be used to estimate a software system's fault content prior to test, or to discriminate between components that are fault-prone and those that are not. The results of these methods can be used to: 1) More accurately focus scarce fault identification resources on those portions of a software system most in need of it. 2) Estimate and forecast the risk of exposure to residual faults in a software system during operation, and develop risk and safety criteria to guide the release of a software system to fielded use. 3) Estimate the efficiency of test suites in detecting residual faults. 4) Estimate the stability of the software maintenance process.

FY12 End of Year Report for NEPP DDR2 Reliability

NASA Technical Reports Server (NTRS)

Guertin, Steven M.

2013-01-01

This document reports the status of the NASA Electronic Parts and Packaging (NEPP) Double Data Rate 2 (DDR2) Reliability effort for FY2012. The task expanded the focus of evaluating reliability effects targeted for device examination. FY11 work highlighted the need to test many more parts and to examine more operating conditions, in order to provide useful recommendations for NASA users of these devices. This year's efforts focused on development of test capabilities, particularly focusing on those that can be used to determine overall lot quality and identify outlier devices, and test methods that can be employed on components for flight use. Flight acceptance of components potentially includes considerable time for up-screening (though this time may not currently be used for much reliability testing). Manufacturers are much more knowledgeable about the relevant reliability mechanisms for each of their devices. We are not in a position to know what the appropriate reliability tests are for any given device, so although reliability testing could be focused for a given device, we are forced to perform a large campaign of reliability tests to identify devices with degraded reliability. With the available up-screening time for NASA parts, it is possible to run many device performance studies. This includes verification of basic datasheet characteristics. Furthermore, it is possible to perform significant pattern sensitivity studies. By doing these studies we can establish higher reliability of flight components. In order to develop these approaches, it is necessary to develop test capability that can identify reliability outliers. To do this we must test many devices to ensure outliers are in the sample, and we must develop characterization capability to measure many different parameters. For FY12 we increased capability for reliability characterization and sample size. We increased sample size this year by moving from loose devices to dual inline memory modules (DIMMs) with an approximate reduction of 20 to 50 times in terms of per device under test (DUT) cost. By increasing sample size we have improved our ability to characterize devices that may be considered reliability outliers. This report provides an update on the effort to improve DDR2 testing capability. Although focused on DDR2, the methods being used can be extended to DDR and DDR3 with relative ease.

The Watch-and-Wait Task: On the Reliability and Validity of a New Method of Assessing Self-Control in Preschool Children

ERIC Educational Resources Information Center

Neubauer, Anna; Gawrilow, Caterina; Hasselhorn, Marcus

2012-01-01

A preschooler's ability to delay gratification in the waiting task is predictive of several developmental outcomes, despite this task's relatively low reliability level. Success in this task depends on the use of distraction strategies. The new Watch-and-Wait Task (WWT) has been developed to enhance reliability and to investigate whether the…

Development of a Simultaneous Extraction and Cleanup Method for Pyrethroid Pesticides from Indoor House Dust Samples

EPA Science Inventory

An efficient and reliable analytical method was developed for the sensitive and selective quantification of pyrethroid pesticides (PYRs) in house dust samples. The method is based on selective pressurized liquid extraction (SPLE) of the dust-bound PYRs into dichloromethane (DCM) wi...

Reliability Analysis of the MSC System

NASA Astrophysics Data System (ADS)

Kim, Young-Soo; Lee, Do-Kyoung; Lee, Chang-Ho; Woo, Sun-Hee

2003-09-01

MSC (Multi-Spectral Camera) is the payload of KOMPSAT-2, which is being developed for earth imaging in optical and near-infrared region. The design of the MSC is completed and its reliability has been assessed from part level to the MSC system level. The reliability was analyzed in worst case and the analysis results showed that the value complies the required value of 0.9. In this paper, a calculation method of reliability for the MSC system is described, and assessment result is presented and discussed.

Verification and Validation in a Rapid Software Development Process

NASA Technical Reports Server (NTRS)

Callahan, John R.; Easterbrook, Steve M.

1997-01-01

The high cost of software production is driving development organizations to adopt more automated design and analysis methods such as rapid prototyping, computer-aided software engineering (CASE) tools, and high-level code generators. Even developers of safety-critical software system have adopted many of these new methods while striving to achieve high levels Of quality and reliability. While these new methods may enhance productivity and quality in many cases, we examine some of the risks involved in the use of new methods in safety-critical contexts. We examine a case study involving the use of a CASE tool that automatically generates code from high-level system designs. We show that while high-level testing on the system structure is highly desirable, significant risks exist in the automatically generated code and in re-validating releases of the generated code after subsequent design changes. We identify these risks and suggest process improvements that retain the advantages of rapid, automated development methods within the quality and reliability contexts of safety-critical projects.

System and Software Reliability (C103)

NASA Technical Reports Server (NTRS)

Wallace, Dolores

2003-01-01

Within the last decade better reliability models (hardware. software, system) than those currently used have been theorized and developed but not implemented in practice. Previous research on software reliability has shown that while some existing software reliability models are practical, they are no accurate enough. New paradigms of development (e.g. OO) have appeared and associated reliability models have been proposed posed but not investigated. Hardware models have been extensively investigated but not integrated into a system framework. System reliability modeling is the weakest of the three. NASA engineers need better methods and tools to demonstrate that the products meet NASA requirements for reliability measurement. For the new models for the software component of the last decade, there is a great need to bring them into a form that they can be used on software intensive systems. The Statistical Modeling and Estimation of Reliability Functions for Systems (SMERFS'3) tool is an existing vehicle that may be used to incorporate these new modeling advances. Adapting some existing software reliability modeling changes to accommodate major changes in software development technology may also show substantial improvement in prediction accuracy. With some additional research, the next step is to identify and investigate system reliability. System reliability models could then be incorporated in a tool such as SMERFS'3. This tool with better models would greatly add value in assess in GSFC projects.

Reliable femoral frame construction based on MRI dedicated to muscles position follow-up.

PubMed

Dubois, G; Bonneau, D; Lafage, V; Rouch, P; Skalli, W

2015-10-01

In vivo follow-up of muscle shape variation represents a challenge when evaluating muscle development due to disease or treatment. Recent developments in muscles reconstruction techniques indicate MRI as a clinical tool for the follow-up of the thigh muscles. The comparison of 3D muscles shape from two different sequences is not easy because there is no common frame. This study proposes an innovative method for the reconstruction of a reliable femoral frame based on the femoral head and both condyles centers. In order to robustify the definition of condylar spheres, an original method was developed to combine the estimation of diameters of both condyles from the lateral antero-posterior distance and the estimation of the spheres center from an optimization process. The influence of spacing between MR slices and of origin positions was studied. For all axes, the proposed method presented an angular error lower than 1° with spacing between slice of 10 mm and the optimal position of the origin was identified at 56 % of the distance between the femoral head center and the barycenter of both condyles. The high reliability of this method provides a robust frame for clinical follow-up based on MRI .

[Development and application of morphological analysis method in Aspergillus niger fermentation].

PubMed

Tang, Wenjun; Xia, Jianye; Chu, Ju; Zhuang, Yingping; Zhang, Siliang

2015-02-01

Filamentous fungi are widely used in industrial fermentation. Particular fungal morphology acts as a critical index for a successful fermentation. To break the bottleneck of morphological analysis, we have developed a reliable method for fungal morphological analysis. By this method, we can prepare hundreds of pellet samples simultaneously and obtain quantitative morphological information at large scale quickly. This method can largely increase the accuracy and reliability of morphological analysis result. Based on that, the studies of Aspergillus niger morphology under different oxygen supply conditions and shear rate conditions were carried out. As a result, the morphological responding patterns of A. niger morphology to these conditions were quantitatively demonstrated, which laid a solid foundation for the further scale-up.

An overview of the mathematical and statistical analysis component of RICIS

NASA Technical Reports Server (NTRS)

Hallum, Cecil R.

1987-01-01

Mathematical and statistical analysis components of RICIS (Research Institute for Computing and Information Systems) can be used in the following problem areas: (1) quantification and measurement of software reliability; (2) assessment of changes in software reliability over time (reliability growth); (3) analysis of software-failure data; and (4) decision logic for whether to continue or stop testing software. Other areas of interest to NASA/JSC where mathematical and statistical analysis can be successfully employed include: math modeling of physical systems, simulation, statistical data reduction, evaluation methods, optimization, algorithm development, and mathematical methods in signal processing.

Developing and validating a nutrition knowledge questionnaire: key methods and considerations.

PubMed

Trakman, Gina Louise; Forsyth, Adrienne; Hoye, Russell; Belski, Regina

2017-10-01

To outline key statistical considerations and detailed methodologies for the development and evaluation of a valid and reliable nutrition knowledge questionnaire. Literature on questionnaire development in a range of fields was reviewed and a set of evidence-based guidelines specific to the creation of a nutrition knowledge questionnaire have been developed. The recommendations describe key qualitative methods and statistical considerations, and include relevant examples from previous papers and existing nutrition knowledge questionnaires. Where details have been omitted for the sake of brevity, the reader has been directed to suitable references. We recommend an eight-step methodology for nutrition knowledge questionnaire development as follows: (i) definition of the construct and development of a test plan; (ii) generation of the item pool; (iii) choice of the scoring system and response format; (iv) assessment of content validity; (v) assessment of face validity; (vi) purification of the scale using item analysis, including item characteristics, difficulty and discrimination; (vii) evaluation of the scale including its factor structure and internal reliability, or Rasch analysis, including assessment of dimensionality and internal reliability; and (viii) gathering of data to re-examine the questionnaire's properties, assess temporal stability and confirm construct validity. Several of these methods have previously been overlooked. The measurement of nutrition knowledge is an important consideration for individuals working in the nutrition field. Improved methods in the development of nutrition knowledge questionnaires, such as the use of factor analysis or Rasch analysis, will enable more confidence in reported measures of nutrition knowledge.

A review of sex estimation techniques during examination of skeletal remains in forensic anthropology casework.

PubMed

Krishan, Kewal; Chatterjee, Preetika M; Kanchan, Tanuj; Kaur, Sandeep; Baryah, Neha; Singh, R K

2016-04-01

Sex estimation is considered as one of the essential parameters in forensic anthropology casework, and requires foremost consideration in the examination of skeletal remains. Forensic anthropologists frequently employ morphologic and metric methods for sex estimation of human remains. These methods are still very imperative in identification process in spite of the advent and accomplishment of molecular techniques. A constant boost in the use of imaging techniques in forensic anthropology research has facilitated to derive as well as revise the available population data. These methods however, are less reliable owing to high variance and indistinct landmark details. The present review discusses the reliability and reproducibility of various analytical approaches; morphological, metric, molecular and radiographic methods in sex estimation of skeletal remains. Numerous studies have shown a higher reliability and reproducibility of measurements taken directly on the bones and hence, such direct methods of sex estimation are considered to be more reliable than the other methods. Geometric morphometric (GM) method and Diagnose Sexuelle Probabiliste (DSP) method are emerging as valid methods and widely used techniques in forensic anthropology in terms of accuracy and reliability. Besides, the newer 3D methods are shown to exhibit specific sexual dimorphism patterns not readily revealed by traditional methods. Development of newer and better methodologies for sex estimation as well as re-evaluation of the existing ones will continue in the endeavour of forensic researchers for more accurate results. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Chapter 15: Reliability of Wind Turbines

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

Sheng, Shuangwen; O'Connor, Ryan

The global wind industry has witnessed exciting developments in recent years. The future will be even brighter with further reductions in capital and operation and maintenance costs, which can be accomplished with improved turbine reliability, especially when turbines are installed offshore. One opportunity for the industry to improve wind turbine reliability is through the exploration of reliability engineering life data analysis based on readily available data or maintenance records collected at typical wind plants. If adopted and conducted appropriately, these analyses can quickly save operation and maintenance costs in a potentially impactful manner. This chapter discusses wind turbine reliability bymore » highlighting the methodology of reliability engineering life data analysis. It first briefly discusses fundamentals for wind turbine reliability and the current industry status. Then, the reliability engineering method for life analysis, including data collection, model development, and forecasting, is presented in detail and illustrated through two case studies. The chapter concludes with some remarks on potential opportunities to improve wind turbine reliability. An owner and operator's perspective is taken and mechanical components are used to exemplify the potential benefits of reliability engineering analysis to improve wind turbine reliability and availability.« less

Development of the adult PedsQL™ neurofibromatosis type 1 module: initial feasibility, reliability and validity.

PubMed

Nutakki, Kavitha; Hingtgen, Cynthia M; Monahan, Patrick; Varni, James W; Swigonski, Nancy L

2013-02-21

Neurofibromatosis type 1 (NF1) is a common autosomal dominant genetic disorder with significant impact on health-related quality of life (HRQOL). Research in understanding the pathogenetic mechanisms of neurofibroma development has led to the use of new clinical trials for the treatment of NF1. One of the most important outcomes of a trial is improvement in quality of life, however, no condition specific HRQOL instrument for NF1 exists. The objective of this study was to develop an NF1 HRQOL instrument as a module of PedsQL™ and to test for its initial feasibility, internal consistency reliability and validity in adults with NF1. The NF1 specific HRQOL instrument was developed using a standard method of PedsQL™ module development - literature review, focus group/semi-structured interviews, cognitive interviews and experts' review of initial draft, pilot testing and field testing. Field testing involved 134 adults with NF1. Feasibility was measured by the percentage of missing responses, internal consistency reliability was measured with Cronbach's alpha and validity was measured by the known-groups method. Feasibility, measured by the percentage of missing responses was 4.8% for all subscales on the adult version of the NF1-specific instrument. Internal consistency reliability for the Total Score (alpha =0.97) and subscale reliabilities ranging from 0.72 to 0.96 were acceptable for group comparisons. The PedsQL™ NF1 module distinguished between NF1 adults with excellent to very good, good, and fair to poor health status. The results demonstrate the initial feasibility, reliability and validity of the PedsQL™ NF1 module in adult patients. The PedsQL™ NF1 Module can be used to understand the multidimensional nature of NF1 on the HRQOL patients with this disorder.

solveME: fast and reliable solution of nonlinear ME models.

PubMed

Yang, Laurence; Ma, Ding; Ebrahim, Ali; Lloyd, Colton J; Saunders, Michael A; Palsson, Bernhard O

2016-09-22

Genome-scale models of metabolism and macromolecular expression (ME) significantly expand the scope and predictive capabilities of constraint-based modeling. ME models present considerable computational challenges: they are much (>30 times) larger than corresponding metabolic reconstructions (M models), are multiscale, and growth maximization is a nonlinear programming (NLP) problem, mainly due to macromolecule dilution constraints. Here, we address these computational challenges. We develop a fast and numerically reliable solution method for growth maximization in ME models using a quad-precision NLP solver (Quad MINOS). Our method was up to 45 % faster than binary search for six significant digits in growth rate. We also develop a fast, quad-precision flux variability analysis that is accelerated (up to 60× speedup) via solver warm-starts. Finally, we employ the tools developed to investigate growth-coupled succinate overproduction, accounting for proteome constraints. Just as genome-scale metabolic reconstructions have become an invaluable tool for computational and systems biologists, we anticipate that these fast and numerically reliable ME solution methods will accelerate the wide-spread adoption of ME models for researchers in these fields.

Designing Glass Panels for Economy and Reliability

NASA Technical Reports Server (NTRS)

Moore, D. M.

1983-01-01

Analytical method determines probability of failure of rectangular glass plates subjected to uniformly distributed loads such as those from wind, earthquake, snow, and deadweight. Developed as aid in design of protective glass covers for solar-cell arrays and solar collectors, method is also useful in estimating the reliability of large windows in buildings exposed to high winds and is adapted to nonlinear stress analysis of simply supported plates of any elastic material.

Data Applicability of Heritage and New Hardware for Launch Vehicle System Reliability Models

NASA Technical Reports Server (NTRS)

Al Hassan Mohammad; Novack, Steven

2015-01-01

Many launch vehicle systems are designed and developed using heritage and new hardware. In most cases, the heritage hardware undergoes modifications to fit new functional system requirements, impacting the failure rates and, ultimately, the reliability data. New hardware, which lacks historical data, is often compared to like systems when estimating failure rates. Some qualification of applicability for the data source to the current system should be made. Accurately characterizing the reliability data applicability and quality under these circumstances is crucial to developing model estimations that support confident decisions on design changes and trade studies. This presentation will demonstrate a data-source classification method that ranks reliability data according to applicability and quality criteria to a new launch vehicle. This method accounts for similarities/dissimilarities in source and applicability, as well as operating environments like vibrations, acoustic regime, and shock. This classification approach will be followed by uncertainty-importance routines to assess the need for additional data to reduce uncertainty.

A method of bias correction for maximal reliability with dichotomous measures.

PubMed

Penev, Spiridon; Raykov, Tenko

2010-02-01

This paper is concerned with the reliability of weighted combinations of a given set of dichotomous measures. Maximal reliability for such measures has been discussed in the past, but the pertinent estimator exhibits a considerable bias and mean squared error for moderate sample sizes. We examine this bias, propose a procedure for bias correction, and develop a more accurate asymptotic confidence interval for the resulting estimator. In most empirically relevant cases, the bias correction and mean squared error correction can be performed simultaneously. We propose an approximate (asymptotic) confidence interval for the maximal reliability coefficient, discuss the implementation of this estimator, and investigate the mean squared error of the associated asymptotic approximation. We illustrate the proposed methods using a numerical example.

Techniques for modeling the reliability of fault-tolerant systems with the Markov state-space approach

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Johnson, Sally C.

1995-01-01

This paper presents a step-by-step tutorial of the methods and the tools that were used for the reliability analysis of fault-tolerant systems. The approach used in this paper is the Markov (or semi-Markov) state-space method. The paper is intended for design engineers with a basic understanding of computer architecture and fault tolerance, but little knowledge of reliability modeling. The representation of architectural features in mathematical models is emphasized. This paper does not present details of the mathematical solution of complex reliability models. Instead, it describes the use of several recently developed computer programs SURE, ASSIST, STEM, and PAWS that automate the generation and the solution of these models.

Assessment of NDE reliability data

NASA Technical Reports Server (NTRS)

Yee, B. G. W.; Couchman, J. C.; Chang, F. H.; Packman, D. F.

1975-01-01

Twenty sets of relevant nondestructive test (NDT) reliability data were identified, collected, compiled, and categorized. A criterion for the selection of data for statistical analysis considerations was formulated, and a model to grade the quality and validity of the data sets was developed. Data input formats, which record the pertinent parameters of the defect/specimen and inspection procedures, were formulated for each NDE method. A comprehensive computer program was written and debugged to calculate the probability of flaw detection at several confidence limits by the binomial distribution. This program also selects the desired data sets for pooling and tests the statistical pooling criteria before calculating the composite detection reliability. An example of the calculated reliability of crack detection in bolt holes by an automatic eddy current method is presented.

Development of a diagnostic test set to assess agreement in breast pathology: practical application of the Guidelines for Reporting Reliability and Agreement Studies (GRRAS).

PubMed

Oster, Natalia V; Carney, Patricia A; Allison, Kimberly H; Weaver, Donald L; Reisch, Lisa M; Longton, Gary; Onega, Tracy; Pepe, Margaret; Geller, Berta M; Nelson, Heidi D; Ross, Tyler R; Tosteson, Aanna N A; Elmore, Joann G

2013-02-05

Diagnostic test sets are a valuable research tool that contributes importantly to the validity and reliability of studies that assess agreement in breast pathology. In order to fully understand the strengths and weaknesses of any agreement and reliability study, however, the methods should be fully reported. In this paper we provide a step-by-step description of the methods used to create four complex test sets for a study of diagnostic agreement among pathologists interpreting breast biopsy specimens. We use the newly developed Guidelines for Reporting Reliability and Agreement Studies (GRRAS) as a basis to report these methods. Breast tissue biopsies were selected from the National Cancer Institute-funded Breast Cancer Surveillance Consortium sites. We used a random sampling stratified according to woman's age (40-49 vs. ≥50), parenchymal breast density (low vs. high) and interpretation of the original pathologist. A 3-member panel of expert breast pathologists first independently interpreted each case using five primary diagnostic categories (non-proliferative changes, proliferative changes without atypia, atypical ductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma). When the experts did not unanimously agree on a case diagnosis a modified Delphi method was used to determine the reference standard consensus diagnosis. The final test cases were stratified and randomly assigned into one of four unique test sets. We found GRRAS recommendations to be very useful in reporting diagnostic test set development and recommend inclusion of two additional criteria: 1) characterizing the study population and 2) describing the methods for reference diagnosis, when applicable.

Risk assessment for construction projects of transport infrastructure objects

NASA Astrophysics Data System (ADS)

Titarenko, Boris

2017-10-01

The paper analyzes and compares different methods of risk assessment for construction projects of transport objects. The management of such type of projects demands application of special probabilistic methods due to large level of uncertainty of their implementation. Risk management in the projects requires the use of probabilistic and statistical methods. The aim of the work is to develop a methodology for using traditional methods in combination with robust methods that allow obtaining reliable risk assessments in projects. The robust approach is based on the principle of maximum likelihood and in assessing the risk allows the researcher to obtain reliable results in situations of great uncertainty. The application of robust procedures allows to carry out a quantitative assessment of the main risk indicators of projects when solving the tasks of managing innovation-investment projects. Calculation of damage from the onset of a risky event is possible by any competent specialist. And an assessment of the probability of occurrence of a risky event requires the involvement of special probabilistic methods based on the proposed robust approaches. Practice shows the effectiveness and reliability of results. The methodology developed in the article can be used to create information technologies and their application in automated control systems for complex projects.

A study of fault prediction and reliability assessment in the SEL environment

NASA Technical Reports Server (NTRS)

Basili, Victor R.; Patnaik, Debabrata

1986-01-01

An empirical study on estimation and prediction of faults, prediction of fault detection and correction effort, and reliability assessment in the Software Engineering Laboratory environment (SEL) is presented. Fault estimation using empirical relationships and fault prediction using curve fitting method are investigated. Relationships between debugging efforts (fault detection and correction effort) in different test phases are provided, in order to make an early estimate of future debugging effort. This study concludes with the fault analysis, application of a reliability model, and analysis of a normalized metric for reliability assessment and reliability monitoring during development of software.

First-order reliability application and verification methods for semistatic structures

NASA Astrophysics Data System (ADS)

Verderaime, V.

1994-11-01

Escalating risks of aerostructures stimulated by increasing size, complexity, and cost should no longer be ignored in conventional deterministic safety design methods. The deterministic pass-fail concept is incompatible with probability and risk assessments; stress audits are shown to be arbitrary and incomplete, and the concept compromises the performance of high-strength materials. A reliability method is proposed that combines first-order reliability principles with deterministic design variables and conventional test techniques to surmount current deterministic stress design and audit deficiencies. Accumulative and propagation design uncertainty errors are defined and appropriately implemented into the classical safety-index expression. The application is reduced to solving for a design factor that satisfies the specified reliability and compensates for uncertainty errors, and then using this design factor as, and instead of, the conventional safety factor in stress analyses. The resulting method is consistent with current analytical skills and verification practices, the culture of most designers, and the development of semistatic structural designs.

Structural Reliability Analysis and Optimization: Use of Approximations

NASA Technical Reports Server (NTRS)

Grandhi, Ramana V.; Wang, Liping

1999-01-01

This report is intended for the demonstration of function approximation concepts and their applicability in reliability analysis and design. Particularly, approximations in the calculation of the safety index, failure probability and structural optimization (modification of design variables) are developed. With this scope in mind, extensive details on probability theory are avoided. Definitions relevant to the stated objectives have been taken from standard text books. The idea of function approximations is to minimize the repetitive use of computationally intensive calculations by replacing them with simpler closed-form equations, which could be nonlinear. Typically, the approximations provide good accuracy around the points where they are constructed, and they need to be periodically updated to extend their utility. There are approximations in calculating the failure probability of a limit state function. The first one, which is most commonly discussed, is how the limit state is approximated at the design point. Most of the time this could be a first-order Taylor series expansion, also known as the First Order Reliability Method (FORM), or a second-order Taylor series expansion (paraboloid), also known as the Second Order Reliability Method (SORM). From the computational procedure point of view, this step comes after the design point identification; however, the order of approximation for the probability of failure calculation is discussed first, and it is denoted by either FORM or SORM. The other approximation of interest is how the design point, or the most probable failure point (MPP), is identified. For iteratively finding this point, again the limit state is approximated. The accuracy and efficiency of the approximations make the search process quite practical for analysis intensive approaches such as the finite element methods; therefore, the crux of this research is to develop excellent approximations for MPP identification and also different approximations including the higher-order reliability methods (HORM) for representing the failure surface. This report is divided into several parts to emphasize different segments of the structural reliability analysis and design. Broadly, it consists of mathematical foundations, methods and applications. Chapter I discusses the fundamental definitions of the probability theory, which are mostly available in standard text books. Probability density function descriptions relevant to this work are addressed. In Chapter 2, the concept and utility of function approximation are discussed for a general application in engineering analysis. Various forms of function representations and the latest developments in nonlinear adaptive approximations are presented with comparison studies. Research work accomplished in reliability analysis is presented in Chapter 3. First, the definition of safety index and most probable point of failure are introduced. Efficient ways of computing the safety index with a fewer number of iterations is emphasized. In chapter 4, the probability of failure prediction is presented using first-order, second-order and higher-order methods. System reliability methods are discussed in chapter 5. Chapter 6 presents optimization techniques for the modification and redistribution of structural sizes for improving the structural reliability. The report also contains several appendices on probability parameters.

Conditional Reliability and the Identification of Communities

DTIC Science & Technology

2009-11-09

screening is needed to find the factors and interactions that may be relevant. This problem arises in numerous different settings : screening using D...related to the core communities than to each other. and 4. Develop a set of computational methods for conditional reliability. A report describing...resilience address the question: What is the probability that k nodes can communicate? The difference is that for k-terminal reliability, the k communicating

The art of fault-tolerant system reliability modeling

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Johnson, Sally C.

1990-01-01

A step-by-step tutorial of the methods and tools used for the reliability analysis of fault-tolerant systems is presented. Emphasis is on the representation of architectural features in mathematical models. Details of the mathematical solution of complex reliability models are not presented. Instead the use of several recently developed computer programs--SURE, ASSIST, STEM, PAWS--which automate the generation and solution of these models is described.

Prognostics-based qualification of high-power white LEDs using Lévy process approach

NASA Astrophysics Data System (ADS)

Yung, Kam-Chuen; Sun, Bo; Jiang, Xiaopeng

2017-01-01

Due to their versatility in a variety of applications and the growing market demand, high-power white light-emitting diodes (LEDs) have attracted considerable attention. Reliability qualification testing is an essential part of the product development process to ensure the reliability of a new LED product before its release. However, the widely used IES-TM-21 method does not provide comprehensive reliability information. For more accurate and effective qualification, this paper presents a novel method based on prognostics techniques. Prognostics is an engineering technology predicting the future reliability or determining the remaining useful lifetime (RUL) of a product by assessing the extent of deviation or degradation from its expected normal operating conditions. A Lévy subordinator of a mixed Gamma and compound Poisson process is used to describe the actual degradation process of LEDs characterized by random sporadic small jumps of degradation degree, and the reliability function is derived for qualification with different distribution forms of jump sizes. The IES LM-80 test results reported by different LED vendors are used to develop and validate the qualification methodology. This study will be helpful for LED manufacturers to reduce the total test time and cost required to qualify the reliability of an LED product.

Distributed collaborative response surface method for mechanical dynamic assembly reliability design

NASA Astrophysics Data System (ADS)

Bai, Guangchen; Fei, Chengwei

2013-11-01

Because of the randomness of many impact factors influencing the dynamic assembly relationship of complex machinery, the reliability analysis of dynamic assembly relationship needs to be accomplished considering the randomness from a probabilistic perspective. To improve the accuracy and efficiency of dynamic assembly relationship reliability analysis, the mechanical dynamic assembly reliability(MDAR) theory and a distributed collaborative response surface method(DCRSM) are proposed. The mathematic model of DCRSM is established based on the quadratic response surface function, and verified by the assembly relationship reliability analysis of aeroengine high pressure turbine(HPT) blade-tip radial running clearance(BTRRC). Through the comparison of the DCRSM, traditional response surface method(RSM) and Monte Carlo Method(MCM), the results show that the DCRSM is not able to accomplish the computational task which is impossible for the other methods when the number of simulation is more than 100 000 times, but also the computational precision for the DCRSM is basically consistent with the MCM and improved by 0.40˜4.63% to the RSM, furthermore, the computational efficiency of DCRSM is up to about 188 times of the MCM and 55 times of the RSM under 10000 times simulations. The DCRSM is demonstrated to be a feasible and effective approach for markedly improving the computational efficiency and accuracy of MDAR analysis. Thus, the proposed research provides the promising theory and method for the MDAR design and optimization, and opens a novel research direction of probabilistic analysis for developing the high-performance and high-reliability of aeroengine.

Reduction of bias and variance for evaluation of computer-aided diagnostic schemes.

PubMed

Li, Qiang; Doi, Kunio

2006-04-01

Computer-aided diagnostic (CAD) schemes have been developed to assist radiologists in detecting various lesions in medical images. In addition to the development, an equally important problem is the reliable evaluation of the performance levels of various CAD schemes. It is good to see that more and more investigators are employing more reliable evaluation methods such as leave-one-out and cross validation, instead of less reliable methods such as resubstitution, for assessing their CAD schemes. However, the common applications of leave-one-out and cross-validation evaluation methods do not necessarily imply that the estimated performance levels are accurate and precise. Pitfalls often occur in the use of leave-one-out and cross-validation evaluation methods, and they lead to unreliable estimation of performance levels. In this study, we first identified a number of typical pitfalls for the evaluation of CAD schemes, and conducted a Monte Carlo simulation experiment for each of the pitfalls to demonstrate quantitatively the extent of bias and/or variance caused by the pitfall. Our experimental results indicate that considerable bias and variance may exist in the estimated performance levels of CAD schemes if one employs various flawed leave-one-out and cross-validation evaluation methods. In addition, for promoting and utilizing a high standard for reliable evaluation of CAD schemes, we attempt to make recommendations, whenever possible, for overcoming these pitfalls. We believe that, with the recommended evaluation methods, we can considerably reduce the bias and variance in the estimated performance levels of CAD schemes.

The Noninvasive Measurement of X-Ray Tube Potential.

NASA Astrophysics Data System (ADS)

Ranallo, Frank Nunzio

In this thesis I briefly describe the design of clinical x-ray imaging systems and also the various methods of measuring x-ray tube potential, both invasive and noninvasive. I also discuss the meaning and usage of the quantities tube potential (kV) and peak tube potential (kVp) with reference to x-ray systems used in medical imaging. I propose that there exist several quantities which describe different important aspects of the tube potential as a function of time. These quantities are measurable and can be well defined. I have developed a list of definitions of these quantities along with suggested names and symbols. I describe the development and physical principles of a superior noninvasive method of tube potential measurement along with the instrumentation used to implement this method. This thesis research resulted in the development of several commercial kVp test devices (or "kVp Meters") for which the actual measurement procedure is simple, rapid, and reliable compared to other methods, invasive or noninvasive. These kVp test devices provide measurements with a high level of accuracy and reliability over a wide range of test conditions. They provide results which are more reliable and clinically meaningful than many other, more primary and invasive methods. The errors inherent in these new kVp test devices were investigated and methods to minimize them are discussed.

An Evidential Reasoning-Based CREAM to Human Reliability Analysis in Maritime Accident Process.

PubMed

Wu, Bing; Yan, Xinping; Wang, Yang; Soares, C Guedes

2017-10-01

This article proposes a modified cognitive reliability and error analysis method (CREAM) for estimating the human error probability in the maritime accident process on the basis of an evidential reasoning approach. This modified CREAM is developed to precisely quantify the linguistic variables of the common performance conditions and to overcome the problem of ignoring the uncertainty caused by incomplete information in the existing CREAM models. Moreover, this article views maritime accident development from the sequential perspective, where a scenario- and barrier-based framework is proposed to describe the maritime accident process. This evidential reasoning-based CREAM approach together with the proposed accident development framework are applied to human reliability analysis of a ship capsizing accident. It will facilitate subjective human reliability analysis in different engineering systems where uncertainty exists in practice. © 2017 Society for Risk Analysis.

Development of a nanosatellite de-orbiting system by reliability based design optimization

NASA Astrophysics Data System (ADS)

Nikbay, Melike; Acar, Pınar; Aslan, Alim Rüstem

2015-12-01

This paper presents design approaches to develop a reliable and efficient de-orbiting system for the 3USAT nanosatellite to provide a beneficial orbital decay process at the end of a mission. A de-orbiting system is initially designed by employing the aerodynamic drag augmentation principle where the structural constraints of the overall satellite system and the aerodynamic forces are taken into account. Next, an alternative de-orbiting system is designed with new considerations and further optimized using deterministic and reliability based design techniques. For the multi-objective design, the objectives are chosen to maximize the aerodynamic drag force through the maximization of the Kapton surface area while minimizing the de-orbiting system mass. The constraints are related in a deterministic manner to the required deployment force, the height of the solar panel hole and the deployment angle. The length and the number of layers of the deployable Kapton structure are used as optimization variables. In the second stage of this study, uncertainties related to both manufacturing and operating conditions of the deployable structure in space environment are considered. These uncertainties are then incorporated into the design process by using different probabilistic approaches such as Monte Carlo Simulation, the First-Order Reliability Method and the Second-Order Reliability Method. The reliability based design optimization seeks optimal solutions using the former design objectives and constraints with the inclusion of a reliability index. Finally, the de-orbiting system design alternatives generated by different approaches are investigated and the reliability based optimum design is found to yield the best solution since it significantly improves both system reliability and performance requirements.

Estimation of Environment-Related Properties of Chemicals for Design of Sustainable Processes: Development of Group-Contribution+ (GC+) Property Models and Uncertainty Analysis

EPA Science Inventory

The aim of this work is to develop group-contribution+ (GC+) method (combined group-contribution (GC) method and atom connectivity index (CI) method) based property models to provide reliable estimations of environment-related properties of organic chemicals together with uncert...

Measurement in Sensory Modulation: The Sensory Processing Scale Assessment

PubMed Central

Miller, Lucy J.; Sullivan, Jillian C.

2014-01-01

OBJECTIVE. Sensory modulation issues have a significant impact on participation in daily life. Moreover, understanding phenotypic variation in sensory modulation dysfunction is crucial for research related to defining homogeneous groups and for clinical work in guiding treatment planning. We thus evaluated the new Sensory Processing Scale (SPS) Assessment. METHOD. Research included item development, behavioral scoring system development, test administration, and item analyses to evaluate reliability and validity across sensory domains. RESULTS. Items with adequate reliability (internal reliability >.4) and discriminant validity (p < .01) were retained. Feedback from the expert panel also contributed to decisions about retaining items in the scale. CONCLUSION. The SPS Assessment appears to be a reliable and valid measure of sensory modulation (scale reliability >.90; discrimination between group effect sizes >1.00). This scale has the potential to aid in differential diagnosis of sensory modulation issues. PMID:25184464

Construction of Response Surface with Higher Order Continuity and Its Application to Reliability Engineering

NASA Technical Reports Server (NTRS)

Krishnamurthy, T.; Romero, V. J.

2002-01-01

The usefulness of piecewise polynomials with C1 and C2 derivative continuity for response surface construction method is examined. A Moving Least Squares (MLS) method is developed and compared with four other interpolation methods, including kriging. First the selected methods are applied and compared with one another in a two-design variables problem with a known theoretical response function. Next the methods are tested in a four-design variables problem from a reliability-based design application. In general the piecewise polynomial with higher order derivative continuity methods produce less error in the response prediction. The MLS method was found to be superior for response surface construction among the methods evaluated.

An Early Years Toolbox for Assessing Early Executive Function, Language, Self-Regulation, and Social Development: Validity, Reliability, and Preliminary Norms

ERIC Educational Resources Information Center

Howard, Steven J.; Melhuish, Edward

2017-01-01

Several methods of assessing executive function (EF), self-regulation, language development, and social development in young children have been developed over previous decades. Yet new technologies make available methods of assessment not previously considered. In resolving conceptual and pragmatic limitations of existing tools, the Early Years…

Development and Reliability of Items Measuring the Nonmedical Use of Prescription Drugs for the Youth Risk Behavior Survey: Results Froman Initial Pilot Test

ERIC Educational Resources Information Center

Howard, Melissa M.; Weiler, Robert M.; Haddox, J. David

2009-01-01

Background: The purpose of this study was to develop and test the reliability of self-report survey items designed to monitor the nonmedical use of prescription drugs among adolescents. Methods: Eighteen nonmedical prescription drug items designed to be congruent with the substance abuse items in the US Centers for Disease Control and Prevention's…

Research on Novel Algorithms for Smart Grid Reliability Assessment and Economic Dispatch

NASA Astrophysics Data System (ADS)

Luo, Wenjin

In this dissertation, several studies of electric power system reliability and economy assessment methods are presented. To be more precise, several algorithms in evaluating power system reliability and economy are studied. Furthermore, two novel algorithms are applied to this field and their simulation results are compared with conventional results. As the electrical power system develops towards extra high voltage, remote distance, large capacity and regional networking, the application of a number of new technique equipments and the electric market system have be gradually established, and the results caused by power cut has become more and more serious. The electrical power system needs the highest possible reliability due to its complication and security. In this dissertation the Boolean logic Driven Markov Process (BDMP) method is studied and applied to evaluate power system reliability. This approach has several benefits. It allows complex dynamic models to be defined, while maintaining its easy readability as conventional methods. This method has been applied to evaluate IEEE reliability test system. The simulation results obtained are close to IEEE experimental data which means that it could be used for future study of the system reliability. Besides reliability, modern power system is expected to be more economic. This dissertation presents a novel evolutionary algorithm named as quantum evolutionary membrane algorithm (QEPS), which combines the concept and theory of quantum-inspired evolutionary algorithm and membrane computation, to solve the economic dispatch problem in renewable power system with on land and offshore wind farms. The case derived from real data is used for simulation tests. Another conventional evolutionary algorithm is also used to solve the same problem for comparison. The experimental results show that the proposed method is quick and accurate to obtain the optimal solution which is the minimum cost for electricity supplied by wind farm system.

System reliability approaches for advanced propulsion system structures

NASA Technical Reports Server (NTRS)

Cruse, T. A.; Mahadevan, S.

1991-01-01

This paper identifies significant issues that pertain to the estimation and use of system reliability in the design of advanced propulsion system structures. Linkages between the reliabilities of individual components and their effect on system design issues such as performance, cost, availability, and certification are examined. The need for system reliability computation to address the continuum nature of propulsion system structures and synergistic progressive damage modes has been highlighted. Available system reliability models are observed to apply only to discrete systems. Therefore a sequential structural reanalysis procedure is formulated to rigorously compute the conditional dependencies between various failure modes. The method is developed in a manner that supports both top-down and bottom-up analyses in system reliability.

Watershed Reliability, Resilience And Vulnerability Analysis Under Uncertainty Using Water Quality Data

EPA Science Inventory

A method for assessment of watershed health is developed by employing measures of reliability, resilience and vulnerability (R-R-V) using stream water quality data. Observed water quality data are usually sparse, so that a water quality time series is often reconstructed using s...

Institutional Research Needs for U. S. Community Colleges.

ERIC Educational Resources Information Center

Washington State Board for Community Coll. Education, Seattle. Research and Planning Office.

Seven problem areas where research is needed critically at the two-year institution level are identified: (1) establish reliability and stability of MIS/data base; (2) find reliable predictive instruments and/or formulae; (3) analyze support services and academic assistance objectives; (4) develop research methods to evaluate curricula; (5)…

Development of a nonlinear vortex method. [steady and unsteady aerodynamic loads of highly sweptback wings

NASA Technical Reports Server (NTRS)

Kandil, O. A.

1981-01-01

Progress is reported in the development of reliable nonlinear vortex methods for predicting the steady and unsteady aerodynamic loads of highly sweptback wings at large angles of attack. Abstracts of the papers, talks, and theses produced through this research are included. The modified nonlinear discrete vortex method and the nonlinear hybrid vortex method are highlighted.

Development and validation of a paediatric long-bone fracture classification. A prospective multicentre study in 13 European paediatric trauma centres

PubMed Central

2011-01-01

Background The aim of this study was to develop a child-specific classification system for long bone fractures and to examine its reliability and validity on the basis of a prospective multicentre study. Methods Using the sequentially developed classification system, three samples of between 30 and 185 paediatric limb fractures from a pool of 2308 fractures documented in two multicenter studies were analysed in a blinded fashion by eight orthopaedic surgeons, on a total of 5 occasions. Intra- and interobserver reliability and accuracy were calculated. Results The reliability improved with successive simplification of the classification. The final version resulted in an overall interobserver agreement of κ = 0.71 with no significant difference between experienced and less experienced raters. Conclusions In conclusion, the evaluation of the newly proposed classification system resulted in a reliable and routinely applicable system, for which training in its proper use may further improve the reliability. It can be recommended as a useful tool for clinical practice and offers the option for developing treatment recommendations and outcome predictions in the future. PMID:21548939

Reliability of the test of gross motor development second edition (TGMD-2) for Kindergarten children in Myanmar

PubMed Central

Aye, Thanda; Oo, Khin Saw; Khin, Myo Thuzar; Kuramoto-Ahuja, Tsugumi; Maruyama, Hitoshi

2017-01-01

[Purpose] The purpose of this study was to investigate reliability of the test of gross motor development second edition (TGMD-2) for Kindergarten children in Myanmar. [Subjects and Methods] Fifty healthy Kindergarten children (23 males, 27 females) whose parents/guardians had given written consent were participated. The subjects were explained and demonstrated all 12 gross motor skills of TGMD-2 before the assessment. Each subject individually performed two trials for each gross motor skill and the performance was video recorded. Three raters separately watched the video recordings and rated for inter-rater reliability. The second assessment was done one month later with 25 out of 50 subjects for test-rest reliability. The video recordings of 12 subjects were randomly selected from the first 50 recordings for intra-rater reliability six weeks after the first assessment. The agreement on the locomotor and object control raw scores and the gross motor quotient (GMQ) were calculated. [Results] The findings of all the reliability coefficients for the locomotor and object control raw scores and the GMQ were interpreted as good and excellent reliability. [Conclusion] The results represented that TGMD-2 is a highly reliable and appropriate assessment tool for assessing gross motor skill development of Kindergarten children in Myanmar. PMID:29184278

Reliability of the test of gross motor development second edition (TGMD-2) for Kindergarten children in Myanmar.

PubMed

Aye, Thanda; Oo, Khin Saw; Khin, Myo Thuzar; Kuramoto-Ahuja, Tsugumi; Maruyama, Hitoshi

2017-10-01

[Purpose] The purpose of this study was to investigate reliability of the test of gross motor development second edition (TGMD-2) for Kindergarten children in Myanmar. [Subjects and Methods] Fifty healthy Kindergarten children (23 males, 27 females) whose parents/guardians had given written consent were participated. The subjects were explained and demonstrated all 12 gross motor skills of TGMD-2 before the assessment. Each subject individually performed two trials for each gross motor skill and the performance was video recorded. Three raters separately watched the video recordings and rated for inter-rater reliability. The second assessment was done one month later with 25 out of 50 subjects for test-rest reliability. The video recordings of 12 subjects were randomly selected from the first 50 recordings for intra-rater reliability six weeks after the first assessment. The agreement on the locomotor and object control raw scores and the gross motor quotient (GMQ) were calculated. [Results] The findings of all the reliability coefficients for the locomotor and object control raw scores and the GMQ were interpreted as good and excellent reliability. [Conclusion] The results represented that TGMD-2 is a highly reliable and appropriate assessment tool for assessing gross motor skill development of Kindergarten children in Myanmar.

Clinical methods to quantify trunk mobility in an elite male surfing population.

PubMed

Furness, James; Climstein, Mike; Sheppard, Jeremy M; Abbott, Allan; Hing, Wayne

2016-05-01

Thoracic mobility in the sagittal and horizontal planes are key requirements in the sport of surfing; however to date the normal values of these movements have not yet been quantified in a surfing population. To develop a reliable method to quantify thoracic mobility in the sagittal plane; to assess the reliability of an existing thoracic rotation method, and quantify thoracic mobility in an elite male surfing population. Clinical Measurement, reliability and comparative study. A total of 30 subjects were used to determine the reliability component. 15 elite surfers were used as part of a comparative analysis with age and gender matched controls. Intraclass correlation coefficient values ranged between 0.95-0.99 (95% CI; 0.89-0.99) for both thoracic methods. The elite surfing group had significantly (p ≤ 0.05) greater rotation than the comparative group (mean rotation 63.57° versus 40.80°, respectively). This study has illustrated reliable methods to assess the thoracic spine in the sagittal plane and thoracic rotation. It has also quantified ROM in a surfing cohort; identifying thoracic rotation as a key movement. This information may provide clinicians, coaches and athletic trainers with imperative information regarding the importance of maintaining adequate thoracic rotation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Probabilistic finite elements for fatigue and fracture analysis

NASA Astrophysics Data System (ADS)

Belytschko, Ted; Liu, Wing Kam

Attenuation is focused on the development of Probabilistic Finite Element Method (PFEM), which combines the finite element method with statistics and reliability methods, and its application to linear, nonlinear structural mechanics problems and fracture mechanics problems. The computational tool based on the Stochastic Boundary Element Method is also given for the reliability analysis of a curvilinear fatigue crack growth. The existing PFEM's have been applied to solve for two types of problems: (1) determination of the response uncertainty in terms of the means, variance and correlation coefficients; and (2) determination the probability of failure associated with prescribed limit states.

Probabilistic finite elements for fatigue and fracture analysis

NASA Technical Reports Server (NTRS)

Belytschko, Ted; Liu, Wing Kam

1992-01-01

Attenuation is focused on the development of Probabilistic Finite Element Method (PFEM), which combines the finite element method with statistics and reliability methods, and its application to linear, nonlinear structural mechanics problems and fracture mechanics problems. The computational tool based on the Stochastic Boundary Element Method is also given for the reliability analysis of a curvilinear fatigue crack growth. The existing PFEM's have been applied to solve for two types of problems: (1) determination of the response uncertainty in terms of the means, variance and correlation coefficients; and (2) determination the probability of failure associated with prescribed limit states.

Optimal clustering of MGs based on droop controller for improving reliability using a hybrid of harmony search and genetic algorithms.

PubMed

Abedini, Mohammad; Moradi, Mohammad H; Hosseinian, S M

2016-03-01

This paper proposes a novel method to address reliability and technical problems of microgrids (MGs) based on designing a number of self-adequate autonomous sub-MGs via adopting MGs clustering thinking. In doing so, a multi-objective optimization problem is developed where power losses reduction, voltage profile improvement and reliability enhancement are considered as the objective functions. To solve the optimization problem a hybrid algorithm, named HS-GA, is provided, based on genetic and harmony search algorithms, and a load flow method is given to model different types of DGs as droop controller. The performance of the proposed method is evaluated in two case studies. The results provide support for the performance of the proposed method. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Reliability analysis of composite structures

NASA Technical Reports Server (NTRS)

Kan, Han-Pin

1992-01-01

A probabilistic static stress analysis methodology has been developed to estimate the reliability of a composite structure. Closed form stress analysis methods are the primary analytical tools used in this methodology. These structural mechanics methods are used to identify independent variables whose variations significantly affect the performance of the structure. Once these variables are identified, scatter in their values is evaluated and statistically characterized. The scatter in applied loads and the structural parameters are then fitted to appropriate probabilistic distribution functions. Numerical integration techniques are applied to compute the structural reliability. The predicted reliability accounts for scatter due to variability in material strength, applied load, fabrication and assembly processes. The influence of structural geometry and mode of failure are also considerations in the evaluation. Example problems are given to illustrate various levels of analytical complexity.

Estimating glomerular filtration rate in oncology patients receiving Cisplatin chemotherapy: Predicted creatinine clearance against 99mTc-DTPA methods

NASA Astrophysics Data System (ADS)

Khaidah Syed Sahab, Sharifah; Manap, Mahayuddin; Hamzah, Fadzilah

2017-05-01

The therapeutic potential of cisplatin as the best anticancer treatment for solid tumor is limited by its potential nephrotoxicity. This study analyses the incidence of cisplatin induced nephrotoxicity in oncology patients through GFR estimation using 99mTc-DTPA plasma sampling (reference method) and to compare with predicted creatinine clearance and Tc-99m renal scintigraphy. A prospective study of 33 oncology patients referred for GFR estimation in Penang Hospital. The incidence of cisplatin induced nephrotoxicity was analysed via radionuclide and creatinine based method. Of 33 samples, only 21 selected for the study. The dose of cisplatin given was 75 mg/m2 for each cycle. The mean difference of GFR pre and post chemotherapy (PSC 2) was 13.38 (-4.60, 31.36) ml/min/1.73m2 (p 0.136). Of 21 patients, 3 developed severe nephrotoxicity (GFR < 50ml/min/1.73 m2) contributing 14.3% of incidence. Bland-Altman plot showed only PSC 1 is in agreement with PSC 2 technique. Intraclass Correlation Coefficients (ICC) also showed that PSC 1 has high degree of reliability in comparison to PSC 2 (p < 0.001). The other methods do not show reliability and agreement in comparison to PSC 2 (p < 0.05). 3 of 21 patients (14.3%) developed severe nephrotoxicity post cisplatin chemotherapy. This percentage is much less than the reported 20 - 25% of cases from other studies, probably due to small sample size and biased study population due to strict exclusion criteria. Radionuclide method for evaluating GFR is the most sensitive method for the detection of cisplatin induced nephrotoxicity by showing 3 of 21 patients developing severe nephrotoxicity. PSC 1 was found to be a reliable substitute of PSC 2. The other methods are not reliable for detection of early nephrotoxicity. We will recommend the use of single plasma sampling method (PSC 1) for GFR estimation in monitoring post cisplatin chemotherapy patients.

Development and psychometric evaluation of the Premarital Sexual Behavior Assessment Scale for Young Women (PSAS-YW): an exploratory mixed method study

PubMed Central

2014-01-01

Background Premarital sexual behaviors are important issue for women’s health. The present study was designed to develop and examine the psychometric properties of a scale in order to identify young women who are at greater risk of premarital sexual behavior. Method This was an exploratory mixed method investigation. Indeed, the study was conducted in two phases. In the first phase, qualitative methods (focus group discussion and individual interview) were applied to generate items and develop the questionnaire. In the second phase, psychometric properties (validity and reliability) of the questionnaire were assessed. Results In the first phase an item pool containing 53 statements related to premarital sexual behavior was generated. In the second phase item reduction was applied and the final version of the questionnaire containing 26 items was developed. The psychometric properties of this final version were assessed and the results showed that the instrument has a good structure, and reliability. The results from exploratory factory analysis indicated a 5-factor solution for the instrument that jointly accounted for the 57.4% of variance observed. The Cronbach’s alpha coefficient for the instrument was found to be 0.87. Conclusion This study provided a valid and reliable scale to identify premarital sexual behavior in young women. Assessment of premarital sexual behavior might help to improve women’s sexual abstinence. PMID:24924696

Use of the smartphone for end vertebra selection in scoliosis.

PubMed

Pepe, Murad; Kocadal, Onur; Iyigun, Abdullah; Gunes, Zafer; Aksahin, Ertugrul; Aktekin, Cem Nuri

2017-03-01

The aim of our study was to develop a smartphone-aided end vertebra selection method and to investigate its effectiveness in Cobb angle measurement. Twenty-nine adolescent idiopathic scoliosis patients' pre-operative posteroanterior scoliosis radiographs were used for end vertebra selection and Cobb angle measurement by standard method and smartphone-aided method. Measurements were performed by 7 examiners. The intraclass correlation coefficient was used to analyze selection and measurement reliability. Summary statistics of variance calculations were used to provide 95% prediction limits for the error in Cobb angle measurements. A paired 2-tailed t test was used to analyze end vertebra selection differences. Mean absolute Cobb angle difference was 3.6° for the manual method and 1.9° for the smartphone-aided method. Both intraobserver and interobserver reliability were found excellent in manual and smartphone set for Cobb angle measurement. Both intraobserver and interobserver reliability were found excellent in manual and smartphone set for end vertebra selection. But reliability values of manual set were lower than smartphone. Two observers selected significantly different end vertebra in their repeated selections for manual method. Smartphone-aided method for end vertebra selection and Cobb angle measurement showed excellent reliability. We can expect a reduction in measurement error rates with the widespread use of this method in clinical practice. Level III, Diagnostic study. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Model of load balancing using reliable algorithm with multi-agent system

NASA Astrophysics Data System (ADS)

Afriansyah, M. F.; Somantri, M.; Riyadi, M. A.

2017-04-01

Massive technology development is linear with the growth of internet users which increase network traffic activity. It also increases load of the system. The usage of reliable algorithm and mobile agent in distributed load balancing is a viable solution to handle the load issue on a large-scale system. Mobile agent works to collect resource information and can migrate according to given task. We propose reliable load balancing algorithm using least time first byte (LFB) combined with information from the mobile agent. In system overview, the methodology consisted of defining identification system, specification requirements, network topology and design system infrastructure. The simulation method for simulated system was using 1800 request for 10 s from the user to the server and taking the data for analysis. Software simulation was based on Apache Jmeter by observing response time and reliability of each server and then compared it with existing method. Results of performed simulation show that the LFB method with mobile agent can perform load balancing with efficient systems to all backend server without bottleneck, low risk of server overload, and reliable.

Design of piezoelectric transducer layer with electromagnetic shielding and high connection reliability

NASA Astrophysics Data System (ADS)

Qiu, Lei; Yuan, Shenfang; Shi, Xiaoling; Huang, Tianxiang

2012-07-01

Piezoelectric transducer (PZT) and Lamb wave based structural health monitoring (SHM) method have been widely studied for on-line SHM of high-performance structures. To monitor large-scale structures, a dense PZTs array is required. In order to improve the placement efficiency and reduce the wire burden of the PZTs array, the concept of the piezoelectric transducers layer (PSL) was proposed. The PSL consists of PZTs, a flexible interlayer with printed wires and signal input/output interface. For on-line SHM on real aircraft structures, there are two main issues on electromagnetic interference and connection reliability of the PSL. To address the issues, an electromagnetic shielding design method of the PSL to reduce spatial electromagnetic noise and crosstalk is proposed and a combined welding-cementation process based connection reliability design method is proposed to enhance the connection reliability between the PZTs and the flexible interlayer. Two experiments on electromagnetic interference suppression are performed to validate the shielding design of the PSL. The experimental results show that the amplitudes of the spatial electromagnetic noise and crosstalk output from the shielded PSL developed by this paper are - 15 dB and - 25 dB lower than those of the ordinary PSL, respectively. Other two experiments on temperature durability ( - 55 °C-80 °C ) and strength durability (160-1600μɛ, one million load cycles) are applied to the PSL to validate the connection reliability. The low repeatability errors (less than 3% and less than 5%, respectively) indicate that the developed PSL is of high connection reliability and long fatigue life.

The reliability of the Australasian Triage Scale: a meta-analysis

PubMed Central

Ebrahimi, Mohsen; Heydari, Abbas; Mazlom, Reza; Mirhaghi, Amir

2015-01-01

BACKGROUND: Although the Australasian Triage Scale (ATS) has been developed two decades ago, its reliability has not been defined; therefore, we present a meta-analyis of the reliability of the ATS in order to reveal to what extent the ATS is reliable. DATA SOURCES: Electronic databases were searched to March 2014. The included studies were those that reported samples size, reliability coefficients, and adequate description of the ATS reliability assessment. The guidelines for reporting reliability and agreement studies (GRRAS) were used. Two reviewers independently examined abstracts and extracted data. The effect size was obtained by the z-transformation of reliability coefficients. Data were pooled with random-effects models, and meta-regression was done based on the method of moment’s estimator. RESULTS: Six studies were included in this study at last. Pooled coefficient for the ATS was substantial 0.428 (95%CI 0.340–0.509). The rate of mis-triage was less than fifty percent. The agreement upon the adult version is higher than the pediatric version. CONCLUSION: The ATS has shown an acceptable level of overall reliability in the emergency department, but it needs more development to reach an almost perfect agreement. PMID:26056538

Influences on the Test-Retest Reliability of Functional Connectivity MRI and its Relationship with Behavioral Utility.

PubMed

Noble, Stephanie; Spann, Marisa N; Tokoglu, Fuyuze; Shen, Xilin; Constable, R Todd; Scheinost, Dustin

2017-11-01

Best practices are currently being developed for the acquisition and processing of resting-state magnetic resonance imaging data used to estimate brain functional organization-or "functional connectivity." Standards have been proposed based on test-retest reliability, but open questions remain. These include how amount of data per subject influences whole-brain reliability, the influence of increasing runs versus sessions, the spatial distribution of reliability, the reliability of multivariate methods, and, crucially, how reliability maps onto prediction of behavior. We collected a dataset of 12 extensively sampled individuals (144 min data each across 2 identically configured scanners) to assess test-retest reliability of whole-brain connectivity within the generalizability theory framework. We used Human Connectome Project data to replicate these analyses and relate reliability to behavioral prediction. Overall, the historical 5-min scan produced poor reliability averaged across connections. Increasing the number of sessions was more beneficial than increasing runs. Reliability was lowest for subcortical connections and highest for within-network cortical connections. Multivariate reliability was greater than univariate. Finally, reliability could not be used to improve prediction; these findings are among the first to underscore this distinction for functional connectivity. A comprehensive understanding of test-retest reliability, including its limitations, supports the development of best practices in the field. © The Author 2017. Published by Oxford University Press.

A Fresh Start for Flood Estimation in Ungauged Basins

NASA Astrophysics Data System (ADS)

Woods, R. A.

2017-12-01

The two standard methods for flood estimation in ungauged basins, regression-based statistical models and rainfall-runoff models using a design rainfall event, have survived relatively unchanged as the methods of choice for more than 40 years. Their technical implementation has developed greatly, but the models' representation of hydrological processes has not, despite a large volume of hydrological research. I suggest it is time to introduce more hydrology into flood estimation. The reliability of the current methods can be unsatisfactory. For example, despite the UK's relatively straightforward hydrology, regression estimates of the index flood are uncertain by +/- a factor of two (for a 95% confidence interval), an impractically large uncertainty for design. The standard error of rainfall-runoff model estimates is not usually known, but available assessments indicate poorer reliability than statistical methods. There is a practical need for improved reliability in flood estimation. Two promising candidates to supersede the existing methods are (i) continuous simulation by rainfall-runoff modelling and (ii) event-based derived distribution methods. The main challenge with continuous simulation methods in ungauged basins is to specify the model structure and parameter values, when calibration data are not available. This has been an active area of research for more than a decade, and this activity is likely to continue. The major challenges for the derived distribution method in ungauged catchments include not only the correct specification of model structure and parameter values, but also antecedent conditions (e.g. seasonal soil water balance). However, a much smaller community of researchers are active in developing or applying the derived distribution approach, and as a result slower progress is being made. A change in needed: surely we have learned enough about hydrology in the last 40 years that we can make a practical hydrological advance on our methods for flood estimation! A shift to new methods for flood estimation will not be taken lightly by practitioners. However, the standard for change is clear - can we develop new methods which give significant improvements in reliability over those existing methods which are demonstrably unsatisfactory?

Identification of the contribution of the ankle and hip joints to multi-segmental balance control

PubMed Central

2013-01-01

Background Human stance involves multiple segments, including the legs and trunk, and requires coordinated actions of both. A novel method was developed that reliably estimates the contribution of the left and right leg (i.e., the ankle and hip joints) to the balance control of individual subjects. Methods The method was evaluated using simulations of a double-inverted pendulum model and the applicability was demonstrated with an experiment with seven healthy and one Parkinsonian participant. Model simulations indicated that two perturbations are required to reliably estimate the dynamics of a double-inverted pendulum balance control system. In the experiment, two multisine perturbation signals were applied simultaneously. The balance control system dynamic behaviour of the participants was estimated by Frequency Response Functions (FRFs), which relate ankle and hip joint angles to joint torques, using a multivariate closed-loop system identification technique. Results In the model simulations, the FRFs were reliably estimated, also in the presence of realistic levels of noise. In the experiment, the participants responded consistently to the perturbations, indicated by low noise-to-signal ratios of the ankle angle (0.24), hip angle (0.28), ankle torque (0.07), and hip torque (0.33). The developed method could detect that the Parkinson patient controlled his balance asymmetrically, that is, the right ankle and hip joints produced more corrective torque. Conclusion The method allows for a reliable estimate of the multisegmental feedback mechanism that stabilizes stance, of individual participants and of separate legs. PMID:23433148

Rollover risk prediction of heavy vehicles by reliability index and empirical modelling

NASA Astrophysics Data System (ADS)

Sellami, Yamine; Imine, Hocine; Boubezoul, Abderrahmane; Cadiou, Jean-Charles

2018-03-01

This paper focuses on a combination of a reliability-based approach and an empirical modelling approach for rollover risk assessment of heavy vehicles. A reliability-based warning system is developed to alert the driver to a potential rollover before entering into a bend. The idea behind the proposed methodology is to estimate the rollover risk by the probability that the vehicle load transfer ratio (LTR) exceeds a critical threshold. Accordingly, a so-called reliability index may be used as a measure to assess the vehicle safe functioning. In the reliability method, computing the maximum of LTR requires to predict the vehicle dynamics over the bend which can be in some cases an intractable problem or time-consuming. With the aim of improving the reliability computation time, an empirical model is developed to substitute the vehicle dynamics and rollover models. This is done by using the SVM (Support Vector Machines) algorithm. The preliminary obtained results demonstrate the effectiveness of the proposed approach.

Reliability Standards of Complex Engineering Systems

NASA Astrophysics Data System (ADS)

Galperin, E. M.; Zayko, V. A.; Gorshkalev, P. A.

2017-11-01

Production and manufacture play an important role in today’s modern society. Industrial production is nowadays characterized by increased and complex communications between its parts. The problem of preventing accidents in a large industrial enterprise becomes especially relevant. In these circumstances, the reliability of enterprise functioning is of particular importance. Potential damage caused by an accident at such enterprise may lead to substantial material losses and, in some cases, can even cause a loss of human lives. That is why industrial enterprise functioning reliability is immensely important. In terms of their reliability, industrial facilities (objects) are divided into simple and complex. Simple objects are characterized by only two conditions: operable and non-operable. A complex object exists in more than two conditions. The main characteristic here is the stability of its operation. This paper develops the reliability indicator combining the set theory methodology and a state space method. Both are widely used to analyze dynamically developing probability processes. The research also introduces a set of reliability indicators for complex technical systems.

Assessment of mesh simplification algorithm quality

NASA Astrophysics Data System (ADS)

Roy, Michael; Nicolier, Frederic; Foufou, S.; Truchetet, Frederic; Koschan, Andreas; Abidi, Mongi A.

2002-03-01

Traditionally, medical geneticists have employed visual inspection (anthroposcopy) to clinically evaluate dysmorphology. In the last 20 years, there has been an increasing trend towards quantitative assessment to render diagnosis of anomalies more objective and reliable. These methods have focused on direct anthropometry, using a combination of classical physical anthropology tools and new instruments tailor-made to describe craniofacial morphometry. These methods are painstaking and require that the patient remain still for extended periods of time. Most recently, semiautomated techniques (e.g., structured light scanning) have been developed to capture the geometry of the face in a matter of seconds. In this paper, we establish that direct anthropometry and structured light scanning yield reliable measurements, with remarkably high levels of inter-rater and intra-rater reliability, as well as validity (contrasting the two methods).

Transmission overhaul estimates for partial and full replacement at repair

NASA Technical Reports Server (NTRS)

Savage, M.; Lewicki, D. G.

1991-01-01

Timely transmission overhauls increase in-flight service reliability greater than the calculated design reliabilities of the individual aircraft transmission components. Although necessary for aircraft safety, transmission overhauls contribute significantly to aircraft expense. Predictions of a transmission's maintenance needs at the design stage should enable the development of more cost effective and reliable transmissions in the future. The frequency is estimated of overhaul along with the number of transmissions or components needed to support the overhaul schedule. Two methods based on the two parameter Weibull statistical distribution for component life are used to estimate the time between transmission overhauls. These methods predict transmission lives for maintenance schedules which repair the transmission with a complete system replacement or repair only failed components of the transmission. An example illustrates the methods.

Development of a PCR-based assay for rapid and reliable identification of pathogenic Fusaria.

PubMed

Mishra, Prashant K; Fox, Roland T V; Culham, Alastair

2003-01-28

Identification of Fusarium species has always been difficult due to confusing phenotypic classification systems. We have developed a fluorescent-based polymerase chain reaction assay that allows for rapid and reliable identification of five toxigenic and pathogenic Fusarium species. The species includes Fusarium avenaceum, F. culmorum, F. equiseti, F. oxysporum and F. sambucinum. The method is based on the PCR amplification of species-specific DNA fragments using fluorescent oligonucleotide primers, which were designed based on sequence divergence within the internal transcribed spacer region of nuclear ribosomal DNA. Besides providing an accurate, reliable, and quick diagnosis of these Fusaria, another advantage with this method is that it reduces the potential for exposure to carcinogenic chemicals as it substitutes the use of fluorescent dyes in place of ethidium bromide. Apart from its multidisciplinary importance and usefulness, it also obviates the need for gel electrophoresis.

A Methodology for the Development of a Reliability Database for an Advanced Reactor Probabilistic Risk Assessment

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

Grabaskas, Dave; Brunett, Acacia J.; Bucknor, Matthew

GE Hitachi Nuclear Energy (GEH) and Argonne National Laboratory are currently engaged in a joint effort to modernize and develop probabilistic risk assessment (PRA) techniques for advanced non-light water reactors. At a high level the primary outcome of this project will be the development of next-generation PRA methodologies that will enable risk-informed prioritization of safety- and reliability-focused research and development, while also identifying gaps that may be resolved through additional research. A subset of this effort is the development of a reliability database (RDB) methodology to determine applicable reliability data for inclusion in the quantification of the PRA. The RDBmore » method developed during this project seeks to satisfy the requirements of the Data Analysis element of the ASME/ANS Non-LWR PRA standard. The RDB methodology utilizes a relevancy test to examine reliability data and determine whether it is appropriate to include as part of the reliability database for the PRA. The relevancy test compares three component properties to establish the level of similarity to components examined as part of the PRA. These properties include the component function, the component failure modes, and the environment/boundary conditions of the component. The relevancy test is used to gauge the quality of data found in a variety of sources, such as advanced reactor-specific databases, non-advanced reactor nuclear databases, and non-nuclear databases. The RDB also establishes the integration of expert judgment or separate reliability analysis with past reliability data. This paper provides details on the RDB methodology, and includes an example application of the RDB methodology for determining the reliability of the intermediate heat exchanger of a sodium fast reactor. The example explores a variety of reliability data sources, and assesses their applicability for the PRA of interest through the use of the relevancy test.« less

Development of a Computerised Method of Determining Aircraft Maintenance Intervals.

DTIC Science & Technology

1985-09-01

Reliability. Vol.17. 1978. pp461-464. 23. , and Shunji Osaki. "Optimum Preventive Maintenance Policies for a 2-Unit Redundant System." IEEE...Transactions on Reliability. Vol.R-23. No.2. June 1974. pp86-91. 24. _ _, and Shunji Osaki. "A Summary of Optimum Preventive Maintenance Policies for a Two-Unit

Measurement Error in Multilevel Models of School and Classroom Environments: Implications for Reliability, Precision, and Prediction. CRESST Report 828

ERIC Educational Resources Information Center

Schweig, Jonathan

2013-01-01

Measuring school and classroom environments has become central in a nation-wide effort to develop comprehensive programs that measure teacher quality and teacher effectiveness. Formulating successful programs necessitates accurate and reliable methods for measuring these environmental variables. This paper uses a generalizability theory framework…

Evaluation of Scale Reliability with Binary Measures Using Latent Variable Modeling

ERIC Educational Resources Information Center

Raykov, Tenko; Dimitrov, Dimiter M.; Asparouhov, Tihomir

2010-01-01

A method for interval estimation of scale reliability with discrete data is outlined. The approach is applicable with multi-item instruments consisting of binary measures, and is developed within the latent variable modeling methodology. The procedure is useful for evaluation of consistency of single measures and of sum scores from item sets…

Evaluation of Weighted Scale Reliability and Criterion Validity: A Latent Variable Modeling Approach

ERIC Educational Resources Information Center

Raykov, Tenko

2007-01-01

A method is outlined for evaluating the reliability and criterion validity of weighted scales based on sets of unidimensional measures. The approach is developed within the framework of latent variable modeling methodology and is useful for point and interval estimation of these measurement quality coefficients in counseling and education…

Integration of tools for the Design and Assessment of High-Performance, Highly Reliable Computing Systems (DAHPHRS), phase 1

NASA Technical Reports Server (NTRS)

Scheper, C.; Baker, R.; Frank, G.; Yalamanchili, S.; Gray, G.

1992-01-01

Systems for Space Defense Initiative (SDI) space applications typically require both high performance and very high reliability. These requirements present the systems engineer evaluating such systems with the extremely difficult problem of conducting performance and reliability trade-offs over large design spaces. A controlled development process supported by appropriate automated tools must be used to assure that the system will meet design objectives. This report describes an investigation of methods, tools, and techniques necessary to support performance and reliability modeling for SDI systems development. Models of the JPL Hypercubes, the Encore Multimax, and the C.S. Draper Lab Fault-Tolerant Parallel Processor (FTPP) parallel-computing architectures using candidate SDI weapons-to-target assignment algorithms as workloads were built and analyzed as a means of identifying the necessary system models, how the models interact, and what experiments and analyses should be performed. As a result of this effort, weaknesses in the existing methods and tools were revealed and capabilities that will be required for both individual tools and an integrated toolset were identified.

The Alzheimer's Disease Knowledge Scale: Development and Psychometric Properties

ERIC Educational Resources Information Center

Carpenter, Brian D.; Balsis, Steve; Otilingam, Poorni G.; Hanson, Priya K.; Gatz, Margaret

2009-01-01

Purpose: This study provides preliminary evidence for the acceptability, reliability, and validity of the new Alzheimer's Disease Knowledge Scale (ADKS), a content and psychometric update to the Alzheimer's Disease Knowledge Test. Design and Methods: Traditional scale development methods were used to generate items and evaluate their psychometric…

Using software metrics and software reliability models to attain acceptable quality software for flight and ground support software for avionic systems

NASA Technical Reports Server (NTRS)

Lawrence, Stella

1992-01-01

This paper is concerned with methods of measuring and developing quality software. Reliable flight and ground support software is a highly important factor in the successful operation of the space shuttle program. Reliability is probably the most important of the characteristics inherent in the concept of 'software quality'. It is the probability of failure free operation of a computer program for a specified time and environment.

Motivational Interviewing Skills in Health Care Encounters (MISHCE): Development and psychometric testing of an assessment tool.

PubMed

Petrova, Tatjana; Kavookjian, Jan; Madson, Michael B; Dagley, John; Shannon, David; McDonough, Sharon K

2015-01-01

Motivational interviewing (MI) has demonstrated a significant impact as an intervention strategy for addiction management, change in lifestyle behaviors, and adherence to prescribed medication and other treatments. Key elements to studying MI include training in MI of professionals who will use it, assessment of skills acquisition in trainees, and the use of a validated skills assessment tool. The purpose of this research project was to develop a psychometrically valid and reliable tool that has been designed to assess MI skills competence in health care provider trainees. The goal was to develop an assessment tool that would evaluate the acquisition and use of specific MI skills and principles, as well as the quality of the patient-provider therapeutic alliance in brief health care encounters. To address this purpose, specific steps were followed, beginning with a literature review. This review contributed to the development of relevant conceptual and operational definitions, selecting a scaling technique and response format, and methods for analyzing validity and reliability. Internal consistency reliability was established on 88 video recorded interactions. The inter-rater and test-retest reliability were established using randomly selected 18 from the 88 interactions. The assessment tool Motivational Interviewing Skills for Health Care Encounters (MISHCE) and a manual for use of the tool were developed. Validity and reliability of MISHCE were examined. Face and content validity were supported with well-defined conceptual and operational definitions and feedback from an expert panel. Reliability was established through internal consistency, inter-rater reliability, and test-retest reliability. The overall internal consistency reliability (Cronbach's alpha) for all fifteen items was 0.75. MISHCE demonstrated good inter-rater reliability and good to excellent test-retest reliability. MISHCE assesses the health provider's level of knowledge and skills in brief disease management encounters. MISHCE also evaluates quality of the patient-provider therapeutic alliance, i.e., the "flow" of the interaction. Copyright © 2015 Elsevier Inc. All rights reserved.

A Psychometric Study of the Bayley Scales of Infant and Toddler Development in Persian Language Children.

PubMed

Azari, Nadia; Soleimani, Farin; Vameghi, Roshanak; Sajedi, Firoozeh; Shahshahani, Soheila; Karimi, Hossein; Kraskian, Adis; Shahrokhi, Amin; Teymouri, Robab; Gharib, Masoud

2017-01-01

Bayley Scales of infant & toddler development is a well-known diagnostic developmental assessment tool for children aged 1-42 months. Our aim was investigating the validity & reliability of this scale in Persian speaking children. The method was descriptive-analytic. Translation- back translation and cultural adaptation was done. Content & face validity of translated scale was determined by experts' opinions. Overall, 403 children aged 1 to 42 months were recruited from health centers of Tehran, during years of 2013-2014 for developmental assessment in cognitive, communicative (receptive & expressive) and motor (fine & gross) domains. Reliability of scale was calculated through three methods; internal consistency using Cronbach's alpha coefficient, test-retest and interrater methods. Construct validity was calculated using factor analysis and comparison of the mean scores methods. Cultural and linguistic changes were made in items of all domains especially on communication subscale. Content and face validity of the test were approved by experts' opinions. Cronbach's alpha coefficient was above 0.74 in all domains. Pearson correlation coefficient in various domains, were ≥ 0.982 in test retest method, and ≥0.993 in inter-rater method. Construct validity of the test was approved by factor analysis. Moreover, the mean scores for the different age groups were compared and statistically significant differences were observed between mean scores of different age groups, that confirms validity of the test. The Bayley Scales of Infant and Toddler Development is a valid and reliable tool for child developmental assessment in Persian language children.

Development and psychometric properties of an informant assessment scale of theory of mind for adults with traumatic brain injury.

PubMed

Zhang, Dengke; Pang, Yanxia; Cai, Weixiong; Fazio, Rachel L; Ge, Jianrong; Su, Qiaorong; Xu, Shuiqin; Pan, Yinan; Chen, Sanmei; Zhang, Hongwei

2016-08-01

Impairment of theory of mind (ToM) is a common phenomenon following traumatic brain injury (TBI) that has clear effects on patients' social functioning. A growing body of research has focused on this area, and several methods have been developed to assess ToM deficiency. Although an informant assessment scale would be useful for examining individuals with TBI, very few studies have adopted this approach. The purpose of the present study was to develop an informant assessment scale of ToM for adults with traumatic brain injury (IASToM-aTBI) and to test its reliability and validity with 196 adults with TBI and 80 normal adults. A 44-item scale was developed following a literature review, interviews with patient informants, consultations with experts, item analysis, and exploratory factor analysis (EFA). The following three common factors were extracted: social interaction, understanding of beliefs, and understanding of emotions. The psychometric analyses indicate that the scale has good internal consistency reliability, split-half reliability, test-retest reliability, inter-rater reliability, structural validity, discriminate validity and criterion validity. These results provide preliminary evidence that supports the reliability and validity of the IASToM-aTBI as a ToM assessment tool for adults with TBI.

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.

Translating the semi-structured assessment for drug dependence and alcoholism in the Western Pacific: rationale, study design and reliability of alcohol dependence.

PubMed

Quinn, Amity E; Rosen, Rochelle K; McGeary, John E; Amoa, Francine; Kranzler, Henry R; Francazio, Sarah; McGarvey, Stephen T; Swift, Robert M

2014-01-01

The aims of this study were to develop a bilingual version of the Semi-Structured Assessment for Drug Dependence and Alcoholism (SSADDA) in English and Samoan and determine the reliability of assessments of alcohol dependence in American Samoa. The study consisted of development and reliability-testing phases. In the development phase, the SSADDA alcohol module was translated and the translation was evaluated through cognitive interviews. In the reliability-testing phase, the bilingual SSADDA was administered to 40 ethnic Samoans, including a sub-sample of 26 individuals who were retested. Cognitive interviews indicated the initial translation was culturally and linguistically appropriate except items pertaining to alcohol tolerance, which were modified to reflect Samoan concepts. SSADDA reliability testing indicated diagnoses of DSM-III-R and DSM-IV alcohol dependence were reliable. Reliability varied by language of administration. The English/Samoan version of the SSADDA is appropriate for the diagnosis of DSM-III-R alcohol dependence, which may be useful in advancing research and public health efforts to address alcohol problems in American Samoa and the Western Pacific. The translation methods may inform researchers translating diagnostic and assessment tools into different languages and cultures. © The Author 2014. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Development of Advanced Verification and Validation Procedures and Tools for the Certification of Learning Systems in Aerospace Applications

NASA Technical Reports Server (NTRS)

Jacklin, Stephen; Schumann, Johann; Gupta, Pramod; Richard, Michael; Guenther, Kurt; Soares, Fola

2005-01-01

Adaptive control technologies that incorporate learning algorithms have been proposed to enable automatic flight control and vehicle recovery, autonomous flight, and to maintain vehicle performance in the face of unknown, changing, or poorly defined operating environments. In order for adaptive control systems to be used in safety-critical aerospace applications, they must be proven to be highly safe and reliable. Rigorous methods for adaptive software verification and validation must be developed to ensure that control system software failures will not occur. Of central importance in this regard is the need to establish reliable methods that guarantee convergent learning, rapid convergence (learning) rate, and algorithm stability. This paper presents the major problems of adaptive control systems that use learning to improve performance. The paper then presents the major procedures and tools presently developed or currently being developed to enable the verification, validation, and ultimate certification of these adaptive control systems. These technologies include the application of automated program analysis methods, techniques to improve the learning process, analytical methods to verify stability, methods to automatically synthesize code, simulation and test methods, and tools to provide on-line software assurance.

The effect of density gradients on hydrometers

NASA Astrophysics Data System (ADS)

Heinonen, Martti; Sillanpää, Sampo

2003-05-01

Hydrometers are simple but effective instruments for measuring the density of liquids. In this work, we studied the effect of non-uniform density of liquid on a hydrometer reading. The effect induced by vertical temperature gradients was investigated theoretically and experimentally. A method for compensating for the effect mathematically was developed and tested with experimental data obtained with the MIKES hydrometer calibration system. In the tests, the method was found reliable. However, the reliability depends on the available information on the hydrometer dimensions and density gradients.

Proceedings of Workshop on Reliability in Computational Mechanics Held in Austin, Texas on October 26-28, 1989

DTIC Science & Technology

1989-10-28

develop mathematical models of nature so as to study and predict the behavior of physical systems. The remarkable advances in technology over the last half...met for three days to discuss and study this ’ect. This volume contains invited papers and selected contributed papers presented at this meeting. The...interesting mixture of application of existing methods to issues of reliability as well as studies of new methods that touch upon or depend upon the

Commercialization of NESSUS: Status

NASA Technical Reports Server (NTRS)

Thacker, Ben H.; Millwater, Harry R.

1991-01-01

A plan was initiated in 1988 to commercialize the Numerical Evaluation of Stochastic Structures Under Stress (NESSUS) probabilistic structural analysis software. The goal of the on-going commercialization effort is to begin the transfer of Probabilistic Structural Analysis Method (PSAM) developed technology into industry and to develop additional funding resources in the general area of structural reliability. The commercialization effort is summarized. The SwRI NESSUS Software System is a general purpose probabilistic finite element computer program using state of the art methods for predicting stochastic structural response due to random loads, material properties, part geometry, and boundary conditions. NESSUS can be used to assess structural reliability, to compute probability of failure, to rank the input random variables by importance, and to provide a more cost effective design than traditional methods. The goal is to develop a general probabilistic structural analysis methodology to assist in the certification of critical components in the next generation Space Shuttle Main Engine.

Quantitation of permethylated N-glycans through multiple-reaction monitoring (MRM) LC-MS/MS.

PubMed

Zhou, Shiyue; Hu, Yunli; DeSantos-Garcia, Janie L; Mechref, Yehia

2015-04-01

The important biological roles of glycans and their implications in disease development and progression have created a demand for the development of sensitive quantitative glycomics methods. Quantitation of glycans existing at low abundance is still analytically challenging. In this study, an N-linked glycans quantitation method using multiple-reaction monitoring (MRM) on a triple quadrupole instrument was developed. Optimum normalized collision energy (CE) for both sialylated and fucosylated N-glycan was determined to be 30%, whereas it was found to be 35% for either fucosylated or sialylated N-glycans. The optimum CE for mannose and complex type N-glycan was determined to be 35%. Additionally, the use of three transitions was shown to facilitate reliable quantitation. A total of 88 N-glycan compositions in human blood serum were quantified using this MRM approach. Reliable detection and quantitation of these glycans was achieved when the equivalence of 0.005 μL of blood serum was analyzed. Accordingly, N-glycans down to the 100th of a μL level can be reliably quantified in pooled human blood serum, spanning a dynamic concentration range of three orders of magnitude. MRM was also effectively utilized to quantitatively compare the expression of N-glycans derived from brain-targeting breast carcinoma cells (MDA-MB-231BR) and metastatic breast cancer cells (MDA-MB-231). Thus, the described MRM method of permethylated N-glycan enables a rapid and reliable identification and quantitation of glycans derived from glycoproteins purified or present in complex biological samples.

Quantitation of Permethylated N-Glycans through Multiple-Reaction Monitoring (MRM) LC-MS/MS

NASA Astrophysics Data System (ADS)

Zhou, Shiyue; Hu, Yunli; DeSantos-Garcia, Janie L.; Mechref, Yehia

2015-04-01

The important biological roles of glycans and their implications in disease development and progression have created a demand for the development of sensitive quantitative glycomics methods. Quantitation of glycans existing at low abundance is still analytically challenging. In this study, an N-linked glycans quantitation method using multiple-reaction monitoring (MRM) on a triple quadrupole instrument was developed. Optimum normalized collision energy (CE) for both sialylated and fucosylated N-glycan was determined to be 30%, whereas it was found to be 35% for either fucosylated or sialylated N-glycans. The optimum CE for mannose and complex type N-glycan was determined to be 35%. Additionally, the use of three transitions was shown to facilitate reliable quantitation. A total of 88 N-glycan compositions in human blood serum were quantified using this MRM approach. Reliable detection and quantitation of these glycans was achieved when the equivalence of 0.005 μL of blood serum was analyzed. Accordingly, N-glycans down to the 100th of a μL level can be reliably quantified in pooled human blood serum, spanning a dynamic concentration range of three orders of magnitude. MRM was also effectively utilized to quantitatively compare the expression of N-glycans derived from brain-targeting breast carcinoma cells (MDA-MB-231BR) and metastatic breast cancer cells (MDA-MB-231). Thus, the described MRM method of permethylated N-glycan enables a rapid and reliable identification and quantitation of glycans derived from glycoproteins purified or present in complex biological samples.

Reliability of semiautomated computational methods for estimating tibiofemoral contact stress in the Multicenter Osteoarthritis Study.

PubMed

Anderson, Donald D; Segal, Neil A; Kern, Andrew M; Nevitt, Michael C; Torner, James C; Lynch, John A

2012-01-01

Recent findings suggest that contact stress is a potent predictor of subsequent symptomatic osteoarthritis development in the knee. However, much larger numbers of knees (likely on the order of hundreds, if not thousands) need to be reliably analyzed to achieve the statistical power necessary to clarify this relationship. This study assessed the reliability of new semiautomated computational methods for estimating contact stress in knees from large population-based cohorts. Ten knees of subjects from the Multicenter Osteoarthritis Study were included. Bone surfaces were manually segmented from sequential 1.0 Tesla magnetic resonance imaging slices by three individuals on two nonconsecutive days. Four individuals then registered the resulting bone surfaces to corresponding bone edges on weight-bearing radiographs, using a semi-automated algorithm. Discrete element analysis methods were used to estimate contact stress distributions for each knee. Segmentation and registration reliabilities (day-to-day and interrater) for peak and mean medial and lateral tibiofemoral contact stress were assessed with Shrout-Fleiss intraclass correlation coefficients (ICCs). The segmentation and registration steps of the modeling approach were found to have excellent day-to-day (ICC 0.93-0.99) and good inter-rater reliability (0.84-0.97). This approach for estimating compartment-specific tibiofemoral contact stress appears to be sufficiently reliable for use in large population-based cohorts.

Reliability testing of a portfolio assessment tool for postgraduate family medicine training in South Africa

PubMed Central

Mash, Bob; Derese, Anselme

2013-01-01

Abstract Background Competency-based education and the validity and reliability of workplace-based assessment of postgraduate trainees have received increasing attention worldwide. Family medicine was recognised as a speciality in South Africa six years ago and a satisfactory portfolio of learning is a prerequisite to sit the national exit exam. A massive scaling up of the number of family physicians is needed in order to meet the health needs of the country. Aim The aim of this study was to develop a reliable, robust and feasible portfolio assessment tool (PAT) for South Africa. Methods Six raters each rated nine portfolios from the Stellenbosch University programme, using the PAT, to test for inter-rater reliability. This rating was repeated three months later to determine test–retest reliability. Following initial analysis and feedback the PAT was modified and the inter-rater reliability again assessed on nine new portfolios. An acceptable intra-class correlation was considered to be > 0.80. Results The total score was found to be reliable, with a coefficient of 0.92. For test–retest reliability, the difference in mean total score was 1.7%, which was not statistically significant. Amongst the subsections, only assessment of the educational meetings and the logbook showed reliability coefficients > 0.80. Conclusion This was the first attempt to develop a reliable, robust and feasible national portfolio assessment tool to assess postgraduate family medicine training in the South African context. The tool was reliable for the total score, but the low reliability of several sections in the PAT helped us to develop 12 recommendations regarding the use of the portfolio, the design of the PAT and the training of raters.

Multi-state time-varying reliability evaluation of smart grid with flexible demand resources utilizing Lz transform

NASA Astrophysics Data System (ADS)

Jia, Heping; Jin, Wende; Ding, Yi; Song, Yonghua; Yu, Dezhao

2017-01-01

With the expanding proportion of renewable energy generation and development of smart grid technologies, flexible demand resources (FDRs) have been utilized as an approach to accommodating renewable energies. However, multiple uncertainties of FDRs may influence reliable and secure operation of smart grid. Multi-state reliability models for a single FDR and aggregating FDRs have been proposed in this paper with regard to responsive abilities for FDRs and random failures for both FDR devices and information system. The proposed reliability evaluation technique is based on Lz transform method which can formulate time-varying reliability indices. A modified IEEE-RTS has been utilized as an illustration of the proposed technique.

A Psychometric Study of the Bayley Scales of Infant and Toddler Development in Persian Language Children

PubMed Central

AZARI, Nadia; SOLEIMANI, Farin; VAMEGHI, Roshanak; SAJEDI, Firoozeh; SHAHSHAHANI, Soheila; KARIMI, Hossein; KRASKIAN, Adis; SHAHROKHI, Amin; TEYMOURI, Robab; GHARIB, Masoud

2017-01-01

Objective Bayley Scales of infant & toddler development is a well-known diagnostic developmental assessment tool for children aged 1–42 months. Our aim was investigating the validity & reliability of this scale in Persian speaking children. Materials & Methods The method was descriptive-analytic. Translation- back translation and cultural adaptation was done. Content & face validity of translated scale was determined by experts’ opinions. Overall, 403 children aged 1 to 42 months were recruited from health centers of Tehran, during years of 2013-2014 for developmental assessment in cognitive, communicative (receptive & expressive) and motor (fine & gross) domains. Reliability of scale was calculated through three methods; internal consistency using Cronbach’s alpha coefficient, test-retest and interrater methods. Construct validity was calculated using factor analysis and comparison of the mean scores methods. Results Cultural and linguistic changes were made in items of all domains especially on communication subscale. Content and face validity of the test were approved by experts’ opinions. Cronbach’s alpha coefficient was above 0.74 in all domains. Pearson correlation coefficient in various domains, were ≥ 0.982 in test retest method, and ≥0.993 in inter-rater method. Construct validity of the test was approved by factor analysis. Moreover, the mean scores for the different age groups were compared and statistically significant differences were observed between mean scores of different age groups, that confirms validity of the test. Conclusion The Bayley Scales of Infant and Toddler Development is a valid and reliable tool for child developmental assessment in Persian language children. PMID:28277556

Structural reliability methods: Code development status

NASA Astrophysics Data System (ADS)

Millwater, Harry R.; Thacker, Ben H.; Wu, Y.-T.; Cruse, T. A.

1991-05-01

The Probabilistic Structures Analysis Method (PSAM) program integrates state of the art probabilistic algorithms with structural analysis methods in order to quantify the behavior of Space Shuttle Main Engine structures subject to uncertain loadings, boundary conditions, material parameters, and geometric conditions. An advanced, efficient probabilistic structural analysis software program, NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) was developed as a deliverable. NESSUS contains a number of integrated software components to perform probabilistic analysis of complex structures. A nonlinear finite element module NESSUS/FEM is used to model the structure and obtain structural sensitivities. Some of the capabilities of NESSUS/FEM are shown. A Fast Probability Integration module NESSUS/FPI estimates the probability given the structural sensitivities. A driver module, PFEM, couples the FEM and FPI. NESSUS, version 5.0, addresses component reliability, resistance, and risk.

Structural reliability methods: Code development status

NASA Technical Reports Server (NTRS)

Millwater, Harry R.; Thacker, Ben H.; Wu, Y.-T.; Cruse, T. A.

1991-01-01

The Probabilistic Structures Analysis Method (PSAM) program integrates state of the art probabilistic algorithms with structural analysis methods in order to quantify the behavior of Space Shuttle Main Engine structures subject to uncertain loadings, boundary conditions, material parameters, and geometric conditions. An advanced, efficient probabilistic structural analysis software program, NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) was developed as a deliverable. NESSUS contains a number of integrated software components to perform probabilistic analysis of complex structures. A nonlinear finite element module NESSUS/FEM is used to model the structure and obtain structural sensitivities. Some of the capabilities of NESSUS/FEM are shown. A Fast Probability Integration module NESSUS/FPI estimates the probability given the structural sensitivities. A driver module, PFEM, couples the FEM and FPI. NESSUS, version 5.0, addresses component reliability, resistance, and risk.

Approximation Model Building for Reliability & Maintainability Characteristics of Reusable Launch Vehicles

NASA Technical Reports Server (NTRS)

Unal, Resit; Morris, W. Douglas; White, Nancy H.; Lepsch, Roger A.; Brown, Richard W.

2000-01-01

This paper describes the development of parametric models for estimating operational reliability and maintainability (R&M) characteristics for reusable vehicle concepts, based on vehicle size and technology support level. A R&M analysis tool (RMAT) and response surface methods are utilized to build parametric approximation models for rapidly estimating operational R&M characteristics such as mission completion reliability. These models that approximate RMAT, can then be utilized for fast analysis of operational requirements, for lifecycle cost estimating and for multidisciplinary sign optimization.

Revisiting Individual Creativity Assessment: Triangulation in Subjective and Objective Assessment Methods

ERIC Educational Resources Information Center

Park, Namgyoo K.; Chun, Monica Youngshin; Lee, Jinju

2016-01-01

Compared to the significant development of creativity studies, individual creativity research has not reached a meaningful consensus regarding the most valid and reliable method for assessing individual creativity. This study revisited 2 of the most popular methods for assessing individual creativity: subjective and objective methods. This study…

Reliability and Validity of a Questionnaire to Measure Consumer Knowledge regarding Safe Practices to Prevent Microbiological Contamination in Restaurants

ERIC Educational Resources Information Center

Uggioni, Paula Lazzarin; Salay, Elisabette

2013-01-01

Objective: The objective of this study was to develop a validated and reliable questionnaire to measure consumer knowledge regarding safe practices to prevent microbiological contamination in restaurants and commercial kitchens. Methods: Non-probabilistic samples of individuals were interviewed in the city of Campinas, Brazil. Questionnaire items…

Reliability and Factor Analyses of a Teacher Efficacy Scale for Nigerian Secondary School Teachers

ERIC Educational Resources Information Center

Faleye, Bamidele Abiodun

2008-01-01

Introduction: The suitability of 52 items for measuring Teacher Efficacy was investigated with the aim of developing and validating a Teacher Efficacy Scale (TES) for Nigerian secondary school teachers. Method: The TES was administered on 2400 teachers (mean age = 36.75 years). Data were subjected to factor and reliability analyses. Results:…

Plateau-patella angle in evaluation of patellar height after total knee arthroplasty.

PubMed

Robin, Brett N; Ellington, Matthew D; Jupiter, Daniel C; Allen, Bryce C

2014-07-01

The plateau-patella angle (PPA) has been proposed as a new and simpler method to describe patellar height. This method has not been used or validated in knees following total knee arthroplasty (TKA). A modified PPA (mPPA) was developed for use in this population. The method was validated by determining the interobserver and intraobserver reliability of the technique in 50 consecutive patients compared to three well-described methods of describing patellar height after TKA. Three observers then evaluated the mPPA of 297 post-operative radiographs to describe a normal range after TKA for a given technique and implant. The interobserver reliability was the highest for the mPPA compared to the other methods. The mean mPPA for the entire cohort was 21.06, 20.49, and 19.94 for the three observers. The modified plateau-patella angle is a reliable way to evaluate patellar height in patients who have undergone total knee arthroplasty. Copyright © 2014 Elsevier Inc. All rights reserved.

Repeated-measure validation of craniofacial metrics from three-dimensional surface scans: application to medical genetics

NASA Astrophysics Data System (ADS)

Lauer, Eric A.; Corner, Brian D.; Li, Peng; Beecher, Robert M.; Deutsch, Curtis

2002-03-01

Traditionally, medical geneticists have employed visual inspection (anthroposcopy) to clinically evaluate dysmorphology. In the last 20 years, there has been an increasing trend towards quantitative assessment to render diagnosis of anomalies more objective and reliable. These methods have focused on direct anthropometry, using a combination of classical physical anthropology tools and new instruments tailor-made to describe craniofacial morphometry. These methods are painstaking and require that the patient remain still for extended periods of time. Most recently, semiautomated techniques (e.g., structured light scanning) have been developed to capture the geometry of the face in a matter of seconds. In this paper, we establish that direct anthropometry and structured light scanning yield reliable measurements, with remarkably high levels of inter-rater and intra-rater reliability, as well as validity (contrasting the two methods).

Note: An online testing method for lifetime projection of high power light-emitting diode under accelerated reliability test.

PubMed

Chen, Qi; Chen, Quan; Luo, Xiaobing

2014-09-01

In recent years, due to the fast development of high power light-emitting diode (LED), its lifetime prediction and assessment have become a crucial issue. Although the in situ measurement has been widely used for reliability testing in laser diode community, it has not been applied commonly in LED community. In this paper, an online testing method for LED life projection under accelerated reliability test was proposed and the prototype was built. The optical parametric data were collected. The systematic error and the measuring uncertainty were calculated to be within 0.2% and within 2%, respectively. With this online testing method, experimental data can be acquired continuously and sufficient amount of data can be gathered. Thus, the projection fitting accuracy can be improved (r(2) = 0.954) and testing duration can be shortened.

Reliability and cost analysis methods

NASA Technical Reports Server (NTRS)

Suich, Ronald C.

1991-01-01

In the design phase of a system, how does a design engineer or manager choose between a subsystem with .990 reliability and a more costly subsystem with .995 reliability? When is the increased cost justified? High reliability is not necessarily an end in itself but may be desirable in order to reduce the expected cost due to subsystem failure. However, this may not be the wisest use of funds since the expected cost due to subsystem failure is not the only cost involved. The subsystem itself may be very costly. We should not consider either the cost of the subsystem or the expected cost due to subsystem failure separately but should minimize the total of the two costs, i.e., the total of the cost of the subsystem plus the expected cost due to subsystem failure. This final report discusses the Combined Analysis of Reliability, Redundancy, and Cost (CARRAC) methods which were developed under Grant Number NAG 3-1100 from the NASA Lewis Research Center. CARRAC methods and a CARRAC computer program employ five models which can be used to cover a wide range of problems. The models contain an option which can include repair of failed modules.

Removing Barriers for Effective Deployment of Intermittent Renewable Generation

NASA Astrophysics Data System (ADS)

Arabali, Amirsaman

The stochastic nature of intermittent renewable resources is the main barrier to effective integration of renewable generation. This problem can be studied from feeder-scale and grid-scale perspectives. Two new stochastic methods are proposed to meet the feeder-scale controllable load with a hybrid renewable generation (including wind and PV) and energy storage system. For the first method, an optimization problem is developed whose objective function is the cost of the hybrid system including the cost of renewable generation and storage subject to constraints on energy storage and shifted load. A smart-grid strategy is developed to shift the load and match the renewable energy generation and controllable load. Minimizing the cost function guarantees minimum PV and wind generation installation, as well as storage capacity selection for supplying the controllable load. A confidence coefficient is allocated to each stochastic constraint which shows to what degree the constraint is satisfied. In the second method, a stochastic framework is developed for optimal sizing and reliability analysis of a hybrid power system including renewable resources (PV and wind) and energy storage system. The hybrid power system is optimally sized to satisfy the controllable load with a specified reliability level. A load-shifting strategy is added to provide more flexibility for the system and decrease the installation cost. Load shifting strategies and their potential impacts on the hybrid system reliability/cost analysis are evaluated trough different scenarios. Using a compromise-solution method, the best compromise between the reliability and cost will be realized for the hybrid system. For the second problem, a grid-scale stochastic framework is developed to examine the storage application and its optimal placement for the social cost and transmission congestion relief of wind integration. Storage systems are optimally placed and adequately sized to minimize the sum of operation and congestion costs over a scheduling period. A technical assessment framework is developed to enhance the efficiency of wind integration and evaluate the economics of storage technologies and conventional gas-fired alternatives. The proposed method is used to carry out a cost-benefit analysis for the IEEE 24-bus system and determine the most economical technology. In order to mitigate the financial and technical concerns of renewable energy integration into the power system, a stochastic framework is proposed for transmission grid reinforcement studies in a power system with wind generation. A multi-stage multi-objective transmission network expansion planning (TNEP) methodology is developed which considers the investment cost, absorption of private investment and reliability of the system as the objective functions. A Non-dominated Sorting Genetic Algorithm (NSGA II) optimization approach is used in combination with a probabilistic optimal power flow (POPF) to determine the Pareto optimal solutions considering the power system uncertainties. Using a compromise-solution method, the best final plan is then realized based on the decision maker preferences. The proposed methodology is applied to the IEEE 24-bus Reliability Tests System (RTS) to evaluate the feasibility and practicality of the developed planning strategy.

The revised NEUROGES-ELAN system: An objective and reliable interdisciplinary analysis tool for nonverbal behavior and gesture.

PubMed

Lausberg, Hedda; Sloetjes, Han

2016-09-01

As visual media spread to all domains of public and scientific life, nonverbal behavior is taking its place as an important form of communication alongside the written and spoken word. An objective and reliable method of analysis for hand movement behavior and gesture is therefore currently required in various scientific disciplines, including psychology, medicine, linguistics, anthropology, sociology, and computer science. However, no adequate common methodological standards have been developed thus far. Many behavioral gesture-coding systems lack objectivity and reliability, and automated methods that register specific movement parameters often fail to show validity with regard to psychological and social functions. To address these deficits, we have combined two methods, an elaborated behavioral coding system and an annotation tool for video and audio data. The NEUROGES-ELAN system is an effective and user-friendly research tool for the analysis of hand movement behavior, including gesture, self-touch, shifts, and actions. Since its first publication in 2009 in Behavior Research Methods, the tool has been used in interdisciplinary research projects to analyze a total of 467 individuals from different cultures, including subjects with mental disease and brain damage. Partly on the basis of new insights from these studies, the system has been revised methodologically and conceptually. The article presents the revised version of the system, including a detailed study of reliability. The improved reproducibility of the revised version makes NEUROGES-ELAN a suitable system for basic empirical research into the relation between hand movement behavior and gesture and cognitive, emotional, and interactive processes and for the development of automated movement behavior recognition methods.

Reliability of center of pressure measures for assessing the development of sitting postural control through the stages of sitting.

PubMed

Wickstrom, Jordan; Stergiou, Nick; Kyvelidou, Anastasia

2017-07-01

Cerebral palsy (CP) impairs an individual's ability to move and control one's posture. Unfortunately, the signs and symptoms of CP may not be apparent before age two. Evaluating sitting posture is a potential way to assess the developing mechanisms that contribute to CP. The purpose of this project was to determine the reliability of linear and nonlinear measures, including inter- and intrastage reliability, when used to analyze the center of pressure (COP) time series during the stages of sitting development in children with typical development (TD) and with/at-risk for cerebral palsy (CP). We hypothesized that nonlinear tools would be more reliable than linear tools in assessing childrens' sitting development, and reliability would increase with development. COP data was recorded for three trials at eight sessions. Linear parameters used were root mean square, range of sway for the anterior-posterior (AP) and medial-lateral (ML) directions, and sway path. Nonlinear parameters used were Approximate Entropy, the largest Lyapunov Exponent, and Correlation Dimension for the AP and ML direction. Participants consisted of 33 children with TD and 26 children with/at-risk for CP. Our results determined that COP is a moderately reliable method for assessing the development of sitting postural control in stages in both groups. Thus, clinicians may be able to use measures from COP data across stages to assess the efficacy of therapeutic interventions that are intended to improve sitting postural abilities in children with/at-risk for CP. Copyright © 2017 Elsevier B.V. All rights reserved.

Techniques for control of long-term reliability of complex integrated circuits. I - Reliability assurance by test vehicle qualification.

NASA Technical Reports Server (NTRS)

Van Vonno, N. W.

1972-01-01

Development of an alternate approach to the conventional methods of reliability assurance for large-scale integrated circuits. The product treated is a large-scale T squared L array designed for space applications. The concept used is that of qualification of product by evaluation of the basic processing used in fabricating the product, providing an insight into its potential reliability. Test vehicles are described which enable evaluation of device characteristics, surface condition, and various parameters of the two-level metallization system used. Evaluation of these test vehicles is performed on a lot qualification basis, with the lot consisting of one wafer. Assembled test vehicles are evaluated by high temperature stress at 300 C for short time durations. Stressing at these temperatures provides a rapid method of evaluation and permits a go/no go decision to be made on the wafer lot in a timely fashion.

A Simple and Reliable Method of Design for Standalone Photovoltaic Systems

NASA Astrophysics Data System (ADS)

Srinivasarao, Mantri; Sudha, K. Rama; Bhanu, C. V. K.

2017-06-01

Standalone photovoltaic (SAPV) systems are seen as a promoting method of electrifying areas of developing world that lack power grid infrastructure. Proliferations of these systems require a design procedure that is simple, reliable and exhibit good performance over its life time. The proposed methodology uses simple empirical formulae and easily available parameters to design SAPV systems, that is, array size with energy storage. After arriving at the different array size (area), performance curves are obtained for optimal design of SAPV system with high amount of reliability in terms of autonomy at a specified value of loss of load probability (LOLP). Based on the array to load ratio (ALR) and levelized energy cost (LEC) through life cycle cost (LCC) analysis, it is shown that the proposed methodology gives better performance, requires simple data and is more reliable when compared with conventional design using monthly average daily load and insolation.

Resting-state test-retest reliability of a priori defined canonical networks over different preprocessing steps.

PubMed

Varikuti, Deepthi P; Hoffstaedter, Felix; Genon, Sarah; Schwender, Holger; Reid, Andrew T; Eickhoff, Simon B

2017-04-01

Resting-state functional connectivity analysis has become a widely used method for the investigation of human brain connectivity and pathology. The measurement of neuronal activity by functional MRI, however, is impeded by various nuisance signals that reduce the stability of functional connectivity. Several methods exist to address this predicament, but little consensus has yet been reached on the most appropriate approach. Given the crucial importance of reliability for the development of clinical applications, we here investigated the effect of various confound removal approaches on the test-retest reliability of functional-connectivity estimates in two previously defined functional brain networks. Our results showed that gray matter masking improved the reliability of connectivity estimates, whereas denoising based on principal components analysis reduced it. We additionally observed that refraining from using any correction for global signals provided the best test-retest reliability, but failed to reproduce anti-correlations between what have been previously described as antagonistic networks. This suggests that improved reliability can come at the expense of potentially poorer biological validity. Consistent with this, we observed that reliability was proportional to the retained variance, which presumably included structured noise, such as reliable nuisance signals (for instance, noise induced by cardiac processes). We conclude that compromises are necessary between maximizing test-retest reliability and removing variance that may be attributable to non-neuronal sources.

Resting-state test-retest reliability of a priori defined canonical networks over different preprocessing steps

PubMed Central

Varikuti, Deepthi P.; Hoffstaedter, Felix; Genon, Sarah; Schwender, Holger; Reid, Andrew T.; Eickhoff, Simon B.

2016-01-01

Resting-state functional connectivity analysis has become a widely used method for the investigation of human brain connectivity and pathology. The measurement of neuronal activity by functional MRI, however, is impeded by various nuisance signals that reduce the stability of functional connectivity. Several methods exist to address this predicament, but little consensus has yet been reached on the most appropriate approach. Given the crucial importance of reliability for the development of clinical applications, we here investigated the effect of various confound removal approaches on the test-retest reliability of functional-connectivity estimates in two previously defined functional brain networks. Our results showed that grey matter masking improved the reliability of connectivity estimates, whereas de-noising based on principal components analysis reduced it. We additionally observed that refraining from using any correction for global signals provided the best test-retest reliability, but failed to reproduce anti-correlations between what have been previously described as antagonistic networks. This suggests that improved reliability can come at the expense of potentially poorer biological validity. Consistent with this, we observed that reliability was proportional to the retained variance, which presumably included structured noise, such as reliable nuisance signals (for instance, noise induced by cardiac processes). We conclude that compromises are necessary between maximizing test-retest reliability and removing variance that may be attributable to non-neuronal sources. PMID:27550015

Environmental Control and Life Support System Reliability for Long-Duration Missions Beyond Lower Earth Orbit

NASA Technical Reports Server (NTRS)

Sargusingh, Miriam J.; Nelson, Jason R.

2014-01-01

NASA has highlighted reliability as critical to future human space exploration, particularly in the area of environmental controls and life support systems. The Advanced Exploration Systems (AES) projects have been encouraged to pursue higher reliability components and systems as part of technology development plans. However, no consensus has been reached on what is meant by improving on reliability, or on how to assess reliability within the AES projects. This became apparent when trying to assess reliability as one of several figures of merit for a regenerable water architecture trade study. In the spring of 2013, the AES Water Recovery Project hosted a series of events at Johnson Space Center with the intended goal of establishing a common language and understanding of NASA's reliability goals, and equipping the projects with acceptable means of assessing the respective systems. This campaign included an educational series in which experts from across the agency and academia provided information on terminology, tools, and techniques associated with evaluating and designing for system reliability. The campaign culminated in a workshop that included members of the Environmental Control and Life Support System and AES communities. The goal of this workshop was to develop a consensus on what reliability means to AES and identify methods for assessing low- to mid-technology readiness level technologies for reliability. This paper details the results of that workshop.

ECLSS Reliability for Long Duration Missions Beyond Lower Earth Orbit

NASA Technical Reports Server (NTRS)

Sargusingh, Miriam J.; Nelson, Jason

2014-01-01

Reliability has been highlighted by NASA as critical to future human space exploration particularly in the area of environmental controls and life support systems. The Advanced Exploration Systems (AES) projects have been encouraged to pursue higher reliability components and systems as part of technology development plans. However there is no consensus on what is meant by improving on reliability; nor on how to assess reliability within the AES projects. This became apparent when trying to assess reliability as one of several figures of merit for a regenerable water architecture trade study. In the spring of 2013, the AES Water Recovery Project (WRP) hosted a series of events at the NASA Johnson Space Center (JSC) with the intended goal of establishing a common language and understanding of our reliability goals, and equipping the projects with acceptable means of assessing our respective systems. This campaign included an educational series in which experts from across the agency and academia provided information on terminology, tools and techniques associated with evalauating and designing for system reliability. The campaign culminated in a workshop at JSC with members of the ECLSS and AES communities with the goal of developing a consensus on what reliability means to AES and identifying methods for assessing our low to mid-technology readiness level (TRL) technologies for reliability. This paper details the results of the workshop.

ECLSS Reliability for Long Duration Missions Beyond Lower Earth Orbit

NASA Technical Reports Server (NTRS)

Sargusingh, Miriam J.; Nelson, Jason

2014-01-01

Reliability has been highlighted by NASA as critical to future human space exploration particularly in the area of environmental controls and life support systems. The Advanced Exploration Systems (AES) projects have been encouraged to pursue higher reliability components and systems as part of technology development plans. However, there is no consensus on what is meant by improving on reliability; nor on how to assess reliability within the AES projects. This became apparent when trying to assess reliability as one of several figures of merit for a regenerable water architecture trade study. In the Spring of 2013, the AES Water Recovery Project (WRP) hosted a series of events at the NASA Johnson Space Center (JSC) with the intended goal of establishing a common language and understanding of our reliability goals and equipping the projects with acceptable means of assessing our respective systems. This campaign included an educational series in which experts from across the agency and academia provided information on terminology, tools and techniques associated with evaluating and designing for system reliability. The campaign culminated in a workshop at JSC with members of the ECLSS and AES communities with the goal of developing a consensus on what reliability means to AES and identifying methods for assessing our low to mid-technology readiness level (TRL) technologies for reliability. This paper details the results of the workshop.

Reliability of the Roussel Uclaf Causality Assessment Method for Assessing Causality in Drug-Induced Liver Injury*

PubMed Central

Rochon, James; Protiva, Petr; Seeff, Leonard B.; Fontana, Robert J.; Liangpunsakul, Suthat; Watkins, Paul B.; Davern, Timothy; McHutchison, John G.

2013-01-01

The Roussel Uclaf Causality Assessment Method (RUCAM) was developed to quantify the strength of association between a liver injury and the medication implicated as causing the injury. However, its reliability in a research setting has never been fully explored. The aim of this study was to determine test-retest and interrater reliabilities of RUCAM in retrospectively-identified cases of drug induced liver injury. The Drug-Induced Liver Injury Network is enrolling well-defined cases of hepatotoxicity caused by isoniazid, phenytoin, clavulanate/amoxicillin, or valproate occurring since 1994. Each case was adjudicated by three reviewers working independently; after an interval of at least 5 months, cases were readjudicated by the same reviewers. A total of 40 drug-induced liver injury cases were enrolled including individuals treated with isoniazid (nine), phenytoin (five), clavulanate/amoxicillin (15), and valproate (11). Mean ± standard deviation age at protocol-defined onset was 44.8 ± 19.5 years; patients were 68% female and 78% Caucasian. Cases were classified as hepatocellular (44%), mixed (28%), or cholestatic (28%). Test-retest differences ranged from −7 to +8 with complete agreement in only 26% of cases. On average, the maximum absolute difference among the three reviewers was 3.1 on the first adjudication and 2.7 on the second, although much of this variability could be attributed to differences between the enrolling investigator and the external reviewers. The test-retest reliability by the same assessors was 0.54 (upper 95% confidence limit = 0.77); the interrater reliability was 0.45 (upper 95% confidence limit = 0.58). Categorizing the RUCAM to a five-category scale improved these reliabilities but only marginally. Conclusion The mediocre reliability of the RUCAM is problematic for future studies of drug-induced liver injury. Alternative methods, including modifying the RUCAM, developing drug-specific instruments, or causality assessment based on expert opinion, may be more appropriate. PMID:18798340

Development and validation of the Myasthenia Gravis Impairment Index

PubMed Central

Bril, Vera; Kapral, Moira; Kulkarni, Abhaya; Davis, Aileen M.

2016-01-01

Objective: We aimed to develop a measure of myasthenia gravis impairment using a previously developed framework and to evaluate reliability and validity, specifically face, content, and construct validity. Methods: The first draft of the Myasthenia Gravis Impairment Index (MGII) included examination items from available measures enriched with newly developed, patient-reported items, modified after patient input. International neuromuscular specialists evaluated face and content validity via an e-mail survey. Test–retest reliability was assessed in stable patients at a 3-week interval and interrater reliability was evaluated in the same day. Construct validity was assessed through correlations between the MGII and other measures and by comparing scores in different patient groups. Results: The first draft was assessed by 18 patients, and 72 specialists answered the survey. The second draft had 7 examination and 22 patient-reported items. Field testing included 200 patients, with 54 patients completing the reliability studies. Test–retest reliability of the total score was good (intraclass correlation coefficient 0.92; 95% confidence interval 0.79–0.94), as was interrater reliability of the examination component (intraclass correlation coefficient 0.81; 95% confidence interval 0.79–0.94). The MGII correlated well with comparison measures, with higher correlations with the MG–activities of daily living (r = 0.91) and MG-specific quality of life 15-item scale (r = 0.78). When assessing different patient groups, the scores followed expected patterns. Conclusions: The MGII was developed using a patient-centered framework of myasthenia-related impairments and incorporating patient input throughout the development process. It is reliable in an outpatient setting and has demonstrated construct validity. Responsiveness studies are under way. PMID:27402891

Development and psychometric evaluation of the Premarital Sexual Behavior Assessment Scale for Young Women (PSAS-YW): an exploratory mixed method study.

PubMed

Rahmani, Azam; Merghati-Khoei, Effat; Moghadam-Banaem, Lida; Hajizadeh, Ebrahim; Hamdieh, Mostafa; Montazeri, Ali

2014-06-13

Premarital sexual behaviors are important issue for women's health. The present study was designed to develop and examine the psychometric properties of a scale in order to identify young women who are at greater risk of premarital sexual behavior. This was an exploratory mixed method investigation. Indeed, the study was conducted in two phases. In the first phase, qualitative methods (focus group discussion and individual interview) were applied to generate items and develop the questionnaire. In the second phase, psychometric properties (validity and reliability) of the questionnaire were assessed. In the first phase an item pool containing 53 statements related to premarital sexual behavior was generated. In the second phase item reduction was applied and the final version of the questionnaire containing 26 items was developed. The psychometric properties of this final version were assessed and the results showed that the instrument has a good structure, and reliability. The results from exploratory factory analysis indicated a 5-factor solution for the instrument that jointly accounted for the 57.4% of variance observed. The Cronbach's alpha coefficient for the instrument was found to be 0.87. This study provided a valid and reliable scale to identify premarital sexual behavior in young women. Assessment of premarital sexual behavior might help to improve women's sexual abstinence.

Reliability of Radioisotope Stirling Convertor Linear Alternator

NASA Technical Reports Server (NTRS)

Shah, Ashwin; Korovaichuk, Igor; Geng, Steven M.; Schreiber, Jeffrey G.

2006-01-01

Onboard radioisotope power systems being developed and planned for NASA s deep-space missions would require reliable design lifetimes of up to 14 years. Critical components and materials of Stirling convertors have been undergoing extensive testing and evaluation in support of a reliable performance for the specified life span. Of significant importance to the successful development of the Stirling convertor is the design of a lightweight and highly efficient linear alternator. Alternator performance could vary due to small deviations in the permanent magnet properties, operating temperature, and component geometries. Durability prediction and reliability of the alternator may be affected by these deviations from nominal design conditions. Therefore, it is important to evaluate the effect of these uncertainties in predicting the reliability of the linear alternator performance. This paper presents a study in which a reliability-based methodology is used to assess alternator performance. The response surface characterizing the induced open-circuit voltage performance is constructed using 3-D finite element magnetic analysis. Fast probability integration method is used to determine the probability of the desired performance and its sensitivity to the alternator design parameters.

Overcoming the Challenges of Unstructured Data in Multisite, Electronic Medical Record-based Abstraction.

PubMed

Polnaszek, Brock; Gilmore-Bykovskyi, Andrea; Hovanes, Melissa; Roiland, Rachel; Ferguson, Patrick; Brown, Roger; Kind, Amy J H

2016-10-01

Unstructured data encountered during retrospective electronic medical record (EMR) abstraction has routinely been identified as challenging to reliably abstract, as these data are often recorded as free text, without limitations to format or structure. There is increased interest in reliably abstracting this type of data given its prominent role in care coordination and communication, yet limited methodological guidance exists. As standard abstraction approaches resulted in substandard data reliability for unstructured data elements collected as part of a multisite, retrospective EMR study of hospital discharge communication quality, our goal was to develop, apply and examine the utility of a phase-based approach to reliably abstract unstructured data. This approach is examined using the specific example of discharge communication for warfarin management. We adopted a "fit-for-use" framework to guide the development and evaluation of abstraction methods using a 4-step, phase-based approach including (1) team building; (2) identification of challenges; (3) adaptation of abstraction methods; and (4) systematic data quality monitoring. Unstructured data elements were the focus of this study, including elements communicating steps in warfarin management (eg, warfarin initiation) and medical follow-up (eg, timeframe for follow-up). After implementation of the phase-based approach, interrater reliability for all unstructured data elements demonstrated κ's of ≥0.89-an average increase of +0.25 for each unstructured data element. As compared with standard abstraction methodologies, this phase-based approach was more time intensive, but did markedly increase abstraction reliability for unstructured data elements within multisite EMR documentation.

Content validity and reliability of test of gross motor development in Chilean children

PubMed Central

Cano-Cappellacci, Marcelo; Leyton, Fernanda Aleitte; Carreño, Joshua Durán

2016-01-01

ABSTRACT OBJECTIVE To validate a Spanish version of the Test of Gross Motor Development (TGMD-2) for the Chilean population. METHODS Descriptive, transversal, non-experimental validity and reliability study. Four translators, three experts and 92 Chilean children, from five to 10 years, students from a primary school in Santiago, Chile, have participated. The Committee of Experts has carried out translation, back-translation and revision processes to determine the translinguistic equivalence and content validity of the test, using the content validity index in 2013. In addition, a pilot implementation was achieved to determine test reliability in Spanish, by using the intraclass correlation coefficient and Bland-Altman method. We evaluated whether the results presented significant differences by replacing the bat with a racket, using T-test. RESULTS We obtained a content validity index higher than 0.80 for language clarity and relevance of the TGMD-2 for children. There were significant differences in the object control subtest when comparing the results with bat and racket. The intraclass correlation coefficient for reliability inter-rater, intra-rater and test-retest reliability was greater than 0.80 in all cases. CONCLUSIONS The TGMD-2 has appropriate content validity to be applied in the Chilean population. The reliability of this test is within the appropriate parameters and its use could be recommended in this population after the establishment of normative data, setting a further precedent for the validation in other Latin American countries. PMID:26815160

Reference values for the muscle power sprint test in 6- to 12-year-old children.

PubMed

Douma-van Riet, Danielle; Verschuren, Olaf; Jelsma, Dorothee; Kruitwagen, Cas; Smits-Engelsman, Bouwien; Takken, Tim

2012-01-01

The aims of this study were (1) to develop centile reference values for anaerobic performance of Dutch children tested using the Muscle Power Sprint Test (MPST) and (2) to examine the test-retest reliability of the MPST. Children who were developing typically (178 boys and 201 girls) and aged 6 to 12 years (mean = 8.9 years) were recruited. The MPST was administered to 379 children, and test-retest reliability was examined in 47 children. MPST scores were transformed into centile curves, which were created using generalized additive models for location, scale, and shape. Height-related reference curves were created for both genders. Excellent (intraclass correlation coefficient = 0.98) test-retest reliability was demonstrated. The reference values for the MPST of children who are developing typically and aged 6 to 12 years can serve as a clinical standard in pediatric physical therapy practice. The MPST is a reliable and practical method for determining anaerobic performance in children.

Reliable aluminum contact formation by electrostatic bonding

NASA Astrophysics Data System (ADS)

Kárpáti, T.; Pap, A. E.; Radnóczi, Gy; Beke, B.; Bársony, I.; Fürjes, P.

2015-07-01

The paper presents a detailed study of a reliable method developed for aluminum fusion wafer bonding assisted by the electrostatic force evolving during the anodic bonding process. The IC-compatible procedure described allows the parallel formation of electrical and mechanical contacts, facilitating a reliable packaging of electromechanical systems with backside electrical contacts. This fusion bonding method supports the fabrication of complex microelectromechanical systems (MEMS) and micro-opto-electromechanical systems (MOEMS) structures with enhanced temperature stability, which is crucial in mechanical sensor applications such as pressure or force sensors. Due to the applied electrical potential of  -1000 V the Al metal layers are compressed by electrostatic force, and at the bonding temperature of 450 °C intermetallic diffusion causes aluminum ions to migrate between metal layers.

Networked Resources, Assessment and Collection Development

ERIC Educational Resources Information Center

Samson, Sue; Derry, Sebastian; Eggleston, Holly

2004-01-01

This project provides a critical evaluation of networked resources as they relate to the library's collection development policy, identifies areas of the curriculum not well represented, establishes a reliable method of assessing usage across all resources, and develops a framework of quantitative data for collection development decision making.

Construct Validity and Reliability of the Tolerance Scale among Iranian College Students

ERIC Educational Resources Information Center

Ersanli, Ercümend; Mameghani, Shiva Saeighi

2016-01-01

In the present study, the Tolerance Scale developed by Ersanli (2014) was adapted to the Iranian culture, and its validity and reliability were investigated in the case of Iranian college students. The participants consisted of 552 Iranian college students (62% male, M = 20.84, S.D.: 1.53) selected using the convenience sampling method. The sample…

Astronomy Teaching Self-Efficacy Belief Scale: The Validity and Reliability Study

ERIC Educational Resources Information Center

Demirci, Filiz; Ozyurek, Cengiz

2018-01-01

The purpose of this study is to develop a reliable and safe scale for determining the self-efficacy levels of science teachers in the teaching of astronomy subjects. The study used a survey approach, which is a qualitative research method. The study was conducted with a total of 106 science teachers working in the secondary schools of Ordu city…

Lifelong Learning Competence Scale (LLLCS): The Study of Validity and Reliability

ERIC Educational Resources Information Center

Uzunboylu, Huseyin; Hursen, Cigdem

2011-01-01

In this research our aim is to develop a scale for lifelong learning competences and investigate the validity and the reliability of the structure of the scale. The participants of this research are 300 secondary school teachers who are randomly selected. The findings on the scale's validity of the structure are computed by the method of factor…

[The application of stereology in radiology imaging and cell biology fields].

PubMed

Hu, Na; Wang, Yan; Feng, Yuanming; Lin, Wang

2012-08-01

Stereology is an interdisciplinary method for 3D morphological study developed from mathematics and morphology. It is widely used in medical image analysis and cell biology studies. Because of its unbiased, simple, fast, reliable and non-invasive characteristics, stereology has been widely used in biomedical areas for quantitative analysis and statistics, such as histology, pathology and medical imaging. Because the stereological parameters show distinct differences in different pathology, many scholars use stereological methods to do quantitative analysis in their studies in recent years, for example, in the areas of the condition of cancer cells, tumor grade, disease development and the patient's prognosis, etc. This paper describes the stereological concept and estimation methods, also illustrates the applications of stereology in the fields of CT images, MRI images and cell biology, and finally reflects the universality, the superiority and reliability of stereology.

TCOPPE school environmental audit tool: assessing safety and walkability of school environments.

PubMed

Lee, Chanam; Kim, Hyung Jin; Dowdy, Diane M; Hoelscher, Deanna M; Ory, Marcia G

2013-09-01

Several environmental audit instruments have been developed for assessing streets, parks and trails, but none for schools. This paper introduces a school audit tool that includes 3 subcomponents: 1) street audit, 2) school site audit, and 3) map audit. It presents the conceptual basis and the development process of this instrument, and the methods and results of the reliability assessments. Reliability tests were conducted by 2 trained auditors on 12 study schools (high-low income and urban-suburban-rural settings). Kappa statistics (categorical, factual items) and ICC (Likert-scale, perceptual items) were used to assess a) interrater, b) test-retest, and c) peak vs. off-peak hour reliability tests. For the interrater reliability test, the average Kappa was 0.839 and the ICC was 0.602. For the test-retest reliability, the average Kappa was 0.903 and the ICC was 0.774. The peak-off peak reliability was 0.801. Rural schools showed the most consistent results in the peak-off peak and test-retest assessments. For interrater tests, urban schools showed the highest ICC, and rural schools showed the highest Kappa. Most items achieved moderate to high levels of reliabilities in all study schools. With proper training, this audit can be used to assess school environments reliably for research, outreach, and policy-support purposes.

Novel shortcut estimation method for regeneration energy of amine solvents in an absorption-based carbon capture process.

PubMed

Kim, Huiyong; Hwang, Sung June; Lee, Kwang Soon

2015-02-03

Among various CO2 capture processes, the aqueous amine-based absorption process is considered the most promising for near-term deployment. However, the performance evaluation of newly developed solvents still requires complex and time-consuming procedures, such as pilot plant tests or the development of a rigorous simulator. Absence of accurate and simple calculation methods for the energy performance at an early stage of process development has lengthened and increased expense of the development of economically feasible CO2 capture processes. In this paper, a novel but simple method to reliably calculate the regeneration energy in a standard amine-based carbon capture process is proposed. Careful examination of stripper behaviors and exploitation of energy balance equations around the stripper allowed for calculation of the regeneration energy using only vapor-liquid equilibrium and caloric data. Reliability of the proposed method was confirmed by comparing to rigorous simulations for two well-known solvents, monoethanolamine (MEA) and piperazine (PZ). The proposed method can predict the regeneration energy at various operating conditions with greater simplicity, greater speed, and higher accuracy than those proposed in previous studies. This enables faster and more precise screening of various solvents and faster optimization of process variables and can eventually accelerate the development of economically deployable CO2 capture processes.

Quantitation of Permethylated N-Glycans through Multiple-Reaction Monitoring (MRM) LC-MS/MS

PubMed Central

Zhou, Shiyue; Hu, Yunli; DeSantos-Garcia, Janie L.; Mechref, Yehia

2015-01-01

The important biological roles of glycans and their implications in disease development and progression have created a demand for the development of sensitive quantitative glycomics methods. Quantitation of glycans existing at low abundance is still analytically challenging. In this study, an N-linked glycans quantitation method using multiple reaction monitoring (MRM) on a triple quadrupole instrument was developed. Optimum normalized collision energy (CE) for both sialylated and fucosylated N-glycan structures was determined to be 30% while it was found to be 35% for either fucosylated or sialylated structures The optimum CE for mannose and complex type N-glycan structures was determined to be 35%. Additionally, the use of three transitions was shown to facilitate reliable quantitation. A total of 88 N-glycan structures in human blood serum were quantified using this MRM approach. Reliable detection and quantitation of these structures was achieved when the equivalence of 0.005 μL of blood serum was analyzed. Accordingly, N-glycans down to the 100th of a μL level can be reliably quantified in pooled human blood serum, spanning a dynamic concentration range of three orders of magnitudes. MRM was also effectively utilized to quantitatively compare the expression of N-glycans derived from brain-targeting breast carcinoma cells (MDA-MB-231BR) and metastatic breast cancer cells (MDA-MB-231). Thus, the described MRM method of permethylated N-glycan structures enables a rapid and reliable identification and quantitation of glycans derived from glycoproteins purified or present in complex biological samples. PMID:25698222

Identifying and classifying hyperostosis frontalis interna via computerized tomography.

PubMed

May, Hila; Peled, Nathan; Dar, Gali; Hay, Ori; Abbas, Janan; Masharawi, Youssef; Hershkovitz, Israel

2010-12-01

The aim of this study was to recognize the radiological characteristics of hyperostosis frontalis interna (HFI) and to establish a valid and reliable method for its identification and classification. A reliability test was carried out on 27 individuals who had undergone a head computerized tomography (CT) scan. Intra-observer reliability was obtained by examining the images three times, by the same researcher, with a 2-week interval between each sample ranking. The inter-observer test was performed by three independent researchers. A validity test was carried out using two methods for identifying and classifying HFI: 46 cadaver skullcaps were ranked twice via computerized tomography scans and then by direct observation. Reliability and validity were calculated using Kappa test (SPSS 15.0). Reliability tests of ranking HFI via CT scans demonstrated good results (K > 0.7). As for validity, a very good consensus was obtained between the CT and direct observation, when moderate and advanced types of HFI were present (K = 0.82). The suggested classification method for HFI, using CT, demonstrated a sensitivity of 84%, specificity of 90.5%, and positive predictive value of 91.3%. In conclusion, volume rendering is a reliable and valid tool for identifying HFI. The suggested three-scale classification is most suitable for radiological diagnosis of the phenomena. Considering the increasing awareness of HFI as an early indicator of a developing malady, this study may assist radiologists in identifying and classifying the phenomena.

The impact of leadership and team behavior on standard of care delivered during human patient simulation: a pilot study for undergraduate medical students.

PubMed

Carlson, Jim; Min, Elana; Bridges, Diane

2009-01-01

Methodology to train team behavior during simulation has received increased attention, but standard performance measures are lacking, especially at the undergraduate level. Our purposes were to develop a reliable team behavior measurement tool and explore the relationship between team behavior and the delivery of an appropriate standard of care specific to the simulated case. Authors developed a unique team measurement tool based on previous work. Trainees participated in a simulated event involving the presentation of acute dyspnea. Performance was rated by separate raters using the team behavior measurement tool. Interrater reliability was assessed. The relationship between team behavior and the standard of care delivered was explored. The instrument proved to be reliable for this case and group of raters. Team behaviors had a positive relationship with the standard of medical care delivered specific to the simulated case. The methods used provide a possible method for training and assessing team performance during simulation.

Mission Reliability Estimation for Repairable Robot Teams

NASA Technical Reports Server (NTRS)

Trebi-Ollennu, Ashitey; Dolan, John; Stancliff, Stephen

2010-01-01

A mission reliability estimation method has been designed to translate mission requirements into choices of robot modules in order to configure a multi-robot team to have high reliability at minimal cost. In order to build cost-effective robot teams for long-term missions, one must be able to compare alternative design paradigms in a principled way by comparing the reliability of different robot models and robot team configurations. Core modules have been created including: a probabilistic module with reliability-cost characteristics, a method for combining the characteristics of multiple modules to determine an overall reliability-cost characteristic, and a method for the generation of legitimate module combinations based on mission specifications and the selection of the best of the resulting combinations from a cost-reliability standpoint. The developed methodology can be used to predict the probability of a mission being completed, given information about the components used to build the robots, as well as information about the mission tasks. In the research for this innovation, sample robot missions were examined and compared to the performance of robot teams with different numbers of robots and different numbers of spare components. Data that a mission designer would need was factored in, such as whether it would be better to have a spare robot versus an equivalent number of spare parts, or if mission cost can be reduced while maintaining reliability using spares. This analytical model was applied to an example robot mission, examining the cost-reliability tradeoffs among different team configurations. Particularly scrutinized were teams using either redundancy (spare robots) or repairability (spare components). Using conservative estimates of the cost-reliability relationship, results show that it is possible to significantly reduce the cost of a robotic mission by using cheaper, lower-reliability components and providing spares. This suggests that the current design paradigm of building a minimal number of highly robust robots may not be the best way to design robots for extended missions.

Establishing survey validity and reliability for American Indians through "think aloud" and test-retest methods.

PubMed

Hauge, Cindy Horst; Jacobs-Knight, Jacque; Jensen, Jamie L; Burgess, Katherine M; Puumala, Susan E; Wilton, Georgiana; Hanson, Jessica D

2015-06-01

The purpose of this study was to use a mixed-methods approach to determine the validity and reliability of measurements used within an alcohol-exposed pregnancy prevention program for American Indian women. To develop validity, content experts provided input into the survey measures, and a "think aloud" methodology was conducted with 23 American Indian women. After revising the measurements based on this input, a test-retest was conducted with 79 American Indian women who were randomized to complete either the original measurements or the new, modified measurements. The test-retest revealed that some of the questions performed better for the modified version, whereas others appeared to be more reliable for the original version. The mixed-methods approach was a useful methodology for gathering feedback on survey measurements from American Indian participants and in indicating specific survey questions that needed to be modified for this population. © The Author(s) 2015.

3D photography is a reliable method of measuring infantile haemangioma volume over time.

PubMed

Robertson, Sarah A; Kimble, Roy M; Storey, Kristen J; Gee Kee, Emma L; Stockton, Kellie A

2016-09-01

Infantile haemangiomas are common lesions of infancy. With the development of novel treatments utilised to accelerate their regression, there is a need for a method of assessing these lesions over time. Volume is an ideal assessment method because of its quantifiable nature. This study investigated whether 3D photography is a valid tool for measuring the volume of infantile haemangiomas over time. Thirteen children with infantile haemangiomas presenting to the Vascular Anomalies Clinic, Royal Children's Hospital/Lady Cilento Children's Hospital treated with propranolol were included in the study. Lesion volume was assessed using 3D photography at presentation, one month and three months follow up. Intrarater reliability was determined by retracing all images several months after the initial mapping. Interrater reliability of the 3D camera software was determined by two investigators, blinded to each other's results, independently assessing infantile haemangioma volume. Lesion volume decreased significantly between presentation and three-month follow-up (p<0.001). Volume intra- and interrater reliability were excellent with ICC 0.991 (95% CI 0.982, 0.995) and 0.978 (95% CI 0.955, 0.989), respectively. This study demonstrates images taken with the 3D LifeViz™ camera and lesion volume calculated with Dermapix® software is a reliable method for assessing infantile haemangioma volume over time. Copyright © 2016 Elsevier Inc. All rights reserved.

Challenges to Global Implementation of Infrared Thermography Technology: Current Perspective

PubMed Central

Shterenshis, Michael

2017-01-01

Medical infrared thermography (IT) produces an image of the infrared waves emitted by the human body as part of the thermoregulation process that can vary in intensity based on the health of the person. This review analyzes recent developments in the use of infrared thermography as a screening and diagnostic tool in clinical and nonclinical settings, and identifies possible future routes for improvement of the method. Currently, infrared thermography is not considered to be a fully reliable diagnostic method. If standard infrared protocol is established and a normative database is available, infrared thermography may become a reliable method for detecting inflammatory processes. PMID:29138741

Challenges to Global Implementation of Infrared Thermography Technology: Current Perspective.

PubMed

Shterenshis, Michael

2017-01-01

Medical infrared thermography (IT) produces an image of the infrared waves emitted by the human body as part of the thermoregulation process that can vary in intensity based on the health of the person. This review analyzes recent developments in the use of infrared thermography as a screening and diagnostic tool in clinical and nonclinical settings, and identifies possible future routes for improvement of the method. Currently, infrared thermography is not considered to be a fully reliable diagnostic method. If standard infrared protocol is established and a normative database is available, infrared thermography may become a reliable method for detecting inflammatory processes.

Environmental and human monitoring of Americium-241 utilizing extraction chromatography and alpha-spectrometry.

PubMed

Goldstein, S J; Hensley, C A; Armenta, C E; Peters, R J

1997-03-01

Recent developments in extraction chromatography have simplified the separation of americium from complex matrices in preparation for alpha-spectroscopy relative to traditional methods. Here we present results of procedures developed/adapted for water, air, and bioassay samples with less than 1 g of inorganic residue. Prior analytical methods required the use of a complex, multistage procedure for separation of americium from these matrices. The newer, simplified procedure requires only a single 2 mL extraction chromatographic separation for isolation of Am and lanthanides from other components of the sample. This method has been implemented on an extensive variety of "real" environmental and bioassay samples from the Los Alamos area, and consistently reliable and accurate results with appropriate detection limits have been obtained. The new method increases analytical throughput by a factor of approximately 2 and decreases environmental hazards from acid and mixed-waste generation relative to the prior technique. Analytical accuracy, reproducibility, and reliability are also significantly improved over the more complex and laborious method used previously.

Special methods for aerodynamic-moment calculations from parachute FSI modeling

NASA Astrophysics Data System (ADS)

Takizawa, Kenji; Tezduyar, Tayfun E.; Boswell, Cody; Tsutsui, Yuki; Montel, Kenneth

2015-06-01

The space-time fluid-structure interaction (STFSI) methods for 3D parachute modeling are now at a level where they can bring reliable, practical analysis to some of the most complex parachute systems, such as spacecraft parachutes. The methods include the Deforming-Spatial-Domain/Stabilized ST method as the core computational technology, and a good number of special FSI methods targeting parachutes. Evaluating the stability characteristics of a parachute based on how the aerodynamic moment varies as a function of the angle of attack is one of the practical analyses that reliable parachute FSI modeling can deliver. We describe the special FSI methods we developed for this specific purpose and present the aerodynamic-moment data obtained from FSI modeling of NASA Orion spacecraft parachutes and Japan Aerospace Exploration Agency (JAXA) subscale parachutes.

Quantitative comparison of in situ soil CO2 flux measurement methods

Treesearch

Jennifer D. Knoepp; James M. Vose

2002-01-01

Development of reliable regional or global carbon budgets requires accurate measurement of soil CO2 flux. We conducted laboratory and field studies to determine the accuracy and comparability of methods commonly used to measure in situ soil CO2 fluxes. Methods compared included CO2...

Optimal Measurement Conditions for Spatiotemporal EEG/MEG Source Analysis.

ERIC Educational Resources Information Center

Huizenga, Hilde M.; Heslenfeld, Dirk J.; Molenaar, Peter C. M.

2002-01-01

Developed a method to determine the required number and position of sensors for human brain electromagnetic source analysis. Studied the method through a simulation study and an empirical study on visual evoked potentials in one adult male. Results indicate the method is fast and reliable and improves source precision. (SLD)

Development of LC/MS/MS Methods for Implementation in US EPA’s Drinking Water Unregulated Contaminant Monitoring Regulations

EPA Science Inventory

Well-characterized and standardized methods are the foundation upon which monitoring of regulated and unregulated contaminants in drinking water are based. To obtain reliable, high quality data for trace analysis of contaminants, these methods must be rugged, selective and sensit...

Reliable Multi Method Assessment of Metacognition Use in Chemistry Problem Solving

ERIC Educational Resources Information Center

Cooper, Melanie M.; Sandi-Urena, Santiago; Stevens, Ron

2008-01-01

Metacognition is fundamental in achieving understanding of chemistry and developing of problem solving skills. This paper describes an across-method-and-time instrument designed to assess the use of metacognition in chemistry problem solving. This multi method instrument combines a self report, namely the Metacognitive Activities Inventory…

A Novel Method to Evaluate the Community Built Environment Using Photographs – Environmental Profile of a Community Health (EPOCH) Photo Neighbourhood Evaluation Tool

PubMed Central

Chow, Clara K.; Corsi, Daniel J.; Lock, Karen; Madhavan, Manisha; Mackie, Pam; Li, Wei; Yi, Sun; Wang, Yang; Swaminathan, Sumathi; Lopez-Jaramillo, Patricio; Gomez-Arbelaez, Diego; Avezum, Álvaro; Lear, Scott A.; Dagenais, Gilles; Teo, Koon; McKee, Martin; Yusuf, Salim

2014-01-01

Background Previous research has shown that environments with features that encourage walking are associated with increased physical activity. Existing methods to assess the built environment using geographical information systems (GIS) data, direct audit or large surveys of the residents face constraints, such as data availability and comparability, when used to study communities in countries in diverse parts of the world. The aim of this study was to develop a method to evaluate features of the built environment of communities using a standard set of photos. In this report we describe the method of photo collection, photo analysis instrument development and inter-rater reliability of the instrument. Methods/Principal Findings A minimum of 5 photos were taken per community in 86 communities in 5 countries according to a standard set of instructions from a designated central point of each community by researchers at each site. A standard pro forma derived from reviewing existing instruments to assess the built environment was developed and used to score the characteristics of each community. Photo sets from each community were assessed independently by three observers in the central research office according to the pro forma and the inter-rater reliability was compared by intra-class correlation (ICC). Overall 87% (53 of 60) items had an ICC of ≥0.70, 7% (4 of 60) had an ICC between 0.60 and 0.70 and 5% (3 of 60) items had an ICC ≤0.50. Conclusions/Significance Analysis of photos using a standardized protocol as described in this study offers a means to obtain reliable and reproducible information on the built environment in communities in very diverse locations around the world. The collection of the photographic data required minimal training and the analysis demonstrated high reliability for the majority of items of interest. PMID:25369366

The Validation of a Case-Based, Cumulative Assessment and Progressions Examination

PubMed Central

Coker, Adeola O.; Copeland, Jeffrey T.; Gottlieb, Helmut B.; Horlen, Cheryl; Smith, Helen E.; Urteaga, Elizabeth M.; Ramsinghani, Sushma; Zertuche, Alejandra; Maize, David

2016-01-01

Objective. To assess content and criterion validity, as well as reliability of an internally developed, case-based, cumulative, high-stakes third-year Annual Student Assessment and Progression Examination (P3 ASAP Exam). Methods. Content validity was assessed through the writing-reviewing process. Criterion validity was assessed by comparing student scores on the P3 ASAP Exam with the nationally validated Pharmacy Curriculum Outcomes Assessment (PCOA). Reliability was assessed with psychometric analysis comparing student performance over four years. Results. The P3 ASAP Exam showed content validity through representation of didactic courses and professional outcomes. Similar scores on the P3 ASAP Exam and PCOA with Pearson correlation coefficient established criterion validity. Consistent student performance using Kuder-Richardson coefficient (KR-20) since 2012 reflected reliability of the examination. Conclusion. Pharmacy schools can implement internally developed, high-stakes, cumulative progression examinations that are valid and reliable using a robust writing-reviewing process and psychometric analyses. PMID:26941435

Paediatric Automatic Phonological Analysis Tools (APAT).

PubMed

Saraiva, Daniela; Lousada, Marisa; Hall, Andreia; Jesus, Luis M T

2017-12-01

To develop the pediatric Automatic Phonological Analysis Tools (APAT) and to estimate inter and intrajudge reliability, content validity, and concurrent validity. The APAT were constructed using Excel spreadsheets with formulas. The tools were presented to an expert panel for content validation. The corpus used in the Portuguese standardized test Teste Fonético-Fonológico - ALPE produced by 24 children with phonological delay or phonological disorder was recorded, transcribed, and then inserted into the APAT. Reliability and validity of APAT were analyzed. The APAT present strong inter- and intrajudge reliability (>97%). The content validity was also analyzed (ICC = 0.71), and concurrent validity revealed strong correlations between computerized and manual (traditional) methods. The development of these tools contributes to fill existing gaps in clinical practice and research, since previously there were no valid and reliable tools/instruments for automatic phonological analysis, which allowed the analysis of different corpora.

Failure analysis of solid rocket apogee motors

NASA Technical Reports Server (NTRS)

Martin, P. J.

1972-01-01

The analysis followed five selected motors through initial design, development, test, qualification, manufacture, and final flight reports. An audit was conducted at the manufacturing plants to complement the literature search with firsthand observations of the current philosophies and practices that affect reliability of the motors. A second literature search emphasized acquisition of spacecraft and satellite data bearing on solid motor reliability. It was concluded that present practices at the plants yield highly reliable flight hardware. Reliability can be further improved by new developments of aft-end bonding and initiator/igniter nondestructive test methods, a safe/arm device, and an insulation formulation. Minimum diagnostic instrumentation is recommended for all motor flights. Surplus motors should be used in margin testing. Criteria should be established for pressure and zone curing. The motor contractor should be represented at launch. New design analyses should be made of stretched motors and spacecraft/motor pairs.

[Reliability and validity of warning signs checklist for screening psychological, behavioral and developmental problems of children].

PubMed

Huang, X N; Zhang, Y; Feng, W W; Wang, H S; Cao, B; Zhang, B; Yang, Y F; Wang, H M; Zheng, Y; Jin, X M; Jia, M X; Zou, X B; Zhao, C X; Robert, J; Jing, Jin

2017-06-02

Objective: To evaluate the reliability and validity of warning signs checklist developed by the National Health and Family Planning Commission of the People's Republic of China (NHFPC), so as to determine the screening effectiveness of warning signs on developmental problems of early childhood. Method: Stratified random sampling method was used to assess the reliability and validity of checklist of warning sign and 2 110 children 0 to 6 years of age(1 513 low-risk subjects and 597 high-risk subjects) were recruited from 11 provinces of China. The reliability evaluation for the warning signs included the test-retest reliability and interrater reliability. With the use of Age and Stage Questionnaire (ASQ) and Gesell Development Diagnosis Scale (GESELL) as the criterion scales, criterion validity was assessed by determining the correlation and consistency between the screening results of warning signs and the criterion scales. Result: In terms of the warning signs, the screening positive rates at different ages ranged from 10.8%(21/141) to 26.2%(51/137). The median (interquartile) testing time for each subject was 1(0.6) minute. Both the test-retest reliability and interrater reliability of warning signs reached 0.7 or above, indicating that the stability was good. In terms of validity assessment, there was remarkable consistency between ASQ and warning signs, with the Kappa value of 0.63. With the use of GESELL as criterion, it was determined that the sensitivity of warning signs in children with suspected developmental delay was 82.2%, and the specificity was 77.7%. The overall Youden index was 0.6. Conclusion: The reliability and validity of warning signs checklist for screening early childhood developmental problems have met the basic requirements of psychological screening scales, with the characteristics of short testing time and easy operation. Thus, this warning signs checklist can be used for screening psychological and behavioral problems of early childhood, especially in community settings.

Reliability of the Cardiff Test of basic life support and automated external defibrillation version 3.1.

PubMed

Whitfield, Richard H; Newcombe, Robert G; Woollard, Malcolm

2003-12-01

The introduction of the European Resuscitation Guidelines (2000) for cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) prompted the development of an up-to-date and reliable method of assessing the quality of performance of CPR in combination with the use of an AED. The Cardiff Test of basic life support (BLS) and AED version 3.1 was developed to meet this need and uses standardised checklists to retrospectively evaluate performance from analyses of video recordings and data drawn from a laptop computer attached to a training manikin. This paper reports the inter- and intra-observer reliability of this test. Data used to assess reliability were obtained from an investigation of CPR and AED skill acquisition in a lay responder AED training programme. Six observers were recruited to evaluate performance in 33 data sets, repeating their evaluation after a minimum interval of 3 weeks. More than 70% of the 42 variables considered in this study had a kappa score of 0.70 or above for inter-observer reliability or were drawn from computer data and therefore not subject to evaluator variability. 85% of the 42 variables had kappa scores for intra-observer reliability of 0.70 or above or were drawn from computer data. The standard deviations for inter- and intra-observer measures of time to first shock were 11.6 and 7.7 s, respectively. The inter- and intra-observer reliability for the majority of the variables in the Cardiff Test of BLS and AED version 3.1 is satisfactory. However, reliability is less acceptable with respect to shaking when checking for responsiveness, initial check/clearing of the airway, checks for signs of circulation, time to first shock and performance of interventions in the correct sequence. Further research is required to determine if modifications to the method of assessing these variables can increase reliability.

Systematic review of methods for quantifying teamwork in the operating theatre

PubMed Central

Marshall, D.; Sykes, M.; McCulloch, P.; Shalhoub, J.; Maruthappu, M.

2018-01-01

Background Teamwork in the operating theatre is becoming increasingly recognized as a major factor in clinical outcomes. Many tools have been developed to measure teamwork. Most fall into two categories: self‐assessment by theatre staff and assessment by observers. A critical and comparative analysis of the validity and reliability of these tools is lacking. Methods MEDLINE and Embase databases were searched following PRISMA guidelines. Content validity was assessed using measurements of inter‐rater agreement, predictive validity and multisite reliability, and interobserver reliability using statistical measures of inter‐rater agreement and reliability. Quantitative meta‐analysis was deemed unsuitable. Results Forty‐eight articles were selected for final inclusion; self‐assessment tools were used in 18 and observational tools in 28, and there were two qualitative studies. Self‐assessment of teamwork by profession varied with the profession of the assessor. The most robust self‐assessment tool was the Safety Attitudes Questionnaire (SAQ), although this failed to demonstrate multisite reliability. The most robust observational tool was the Non‐Technical Skills (NOTECHS) system, which demonstrated both test–retest reliability (P > 0·09) and interobserver reliability (Rwg = 0·96). Conclusion Self‐assessment of teamwork by the theatre team was influenced by professional differences. Observational tools, when used by trained observers, circumvented this.

Optimizing the Reliability and Performance of Service Composition Applications with Fault Tolerance in Wireless Sensor Networks

PubMed Central

Wu, Zhao; Xiong, Naixue; Huang, Yannong; Xu, Degang; Hu, Chunyang

2015-01-01

The services composition technology provides flexible methods for building service composition applications (SCAs) in wireless sensor networks (WSNs). The high reliability and high performance of SCAs help services composition technology promote the practical application of WSNs. The optimization methods for reliability and performance used for traditional software systems are mostly based on the instantiations of software components, which are inapplicable and inefficient in the ever-changing SCAs in WSNs. In this paper, we consider the SCAs with fault tolerance in WSNs. Based on a Universal Generating Function (UGF) we propose a reliability and performance model of SCAs in WSNs, which generalizes a redundancy optimization problem to a multi-state system. Based on this model, an efficient optimization algorithm for reliability and performance of SCAs in WSNs is developed based on a Genetic Algorithm (GA) to find the optimal structure of SCAs with fault-tolerance in WSNs. In order to examine the feasibility of our algorithm, we have evaluated the performance. Furthermore, the interrelationships between the reliability, performance and cost are investigated. In addition, a distinct approach to determine the most suitable parameters in the suggested algorithm is proposed. PMID:26561818

Development of the Anxiety Scale for Natural Disaster: Examination of its Reliability

NASA Astrophysics Data System (ADS)

Matsumoto, Miki; Yatabe, Ryuichi

The objective of present study was to develop the a nxiety scale for natural disaster, and to examineits reliability. We developed the 14 items for the anxiety scale based on anticipated damage of Nankai earthquake in Ehime prefecture. The subjects consist of 391 people in Yawatahama city, Ehime prefecture. Firstly, we analyzed the latent factors which influenced the anxiety for natural disaster by using the factor analysis method. Secondly, we cal culated Cronbach's coefficient alpha. The result of the factor analysis confirmed the three factors such as "anxiety for lifeline damage", "anxiety for second ary disaster" and "fear for others". Cronbach's coefficient alpha for each factor showed the high interna l consistency reliability. We considered that each factor could prove to be a valuable tool for researc h about the person's anxiety for natural disaster.

Methodology for Developing a New EFNEP Food and Physical Activity Behaviors Questionnaire.

PubMed

Murray, Erin K; Auld, Garry; Baker, Susan S; Barale, Karen; Franck, Karen; Khan, Tarana; Palmer-Keenan, Debra; Walsh, Jennifer

2017-10-01

Research methods are described for developing a food and physical activity behaviors questionnaire for the Expanded Food and Nutrition Education Program (EFNEP), a US Department of Agriculture nutrition education program serving low-income families. Mixed-methods observational study. The questionnaire will include 5 domains: (1) diet quality, (2) physical activity, (3) food safety, (4) food security, and (5) food resource management. A 5-stage process will be used to assess the questionnaire's test-retest reliability and content, face, and construct validity. Research teams across the US will coordinate questionnaire development and testing nationally. Convenience samples of low-income EFNEP, or EFNEP-eligible, adult participants across the US. A 5-stage process: (1) prioritize domain concepts to evaluate (2) question generation and content analysis panel, (3) question pretesting using cognitive interviews, (4) test-retest reliability assessment, and (5) construct validity testing. A nationally tested valid and reliable food and physical activity behaviors questionnaire for low-income adults to evaluate EFNEP's effectiveness. Cognitive interviews will be summarized to identify themes and dominant trends. Paired t tests (P ≤ .05) and Spearman and intra-class correlation coefficients (r > .5) will be conducted to assess reliability. Construct validity will be assessed using Wilcoxon t test (P ≤ .05), Spearman correlations, and Bland-Altman plots. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

A Conflict Management Scale for Pharmacy

PubMed Central

Gregory, Paul A.; Martin, Craig

2009-01-01

Objectives To develop and establish the validity and reliability of a conflict management scale specific to pharmacy practice and education. Methods A multistage inventory-item development process was undertaken involving 93 pharmacists and using a previously described explanatory model for conflict in pharmacy practice. A 19-item inventory was developed, field tested, and validated. Results The conflict management scale (CMS) demonstrated an acceptable degree of reliability and validity for use in educational or practice settings to promote self-reflection and self-awareness regarding individuals' conflict management styles. Conclusions The CMS provides a unique, pharmacy-specific method for individuals to determine and reflect upon their own conflict management styles. As part of an educational program to facilitate self-reflection and heighten self-awareness, the CMS may be a useful tool to promote discussions related to an important part of pharmacy practice. PMID:19960081

Measuring the Characteristic Topography of Brain Stiffness with Magnetic Resonance Elastography

PubMed Central

Murphy, Matthew C.; Huston, John; Jack, Clifford R.; Glaser, Kevin J.; Senjem, Matthew L.; Chen, Jun; Manduca, Armando; Felmlee, Joel P.; Ehman, Richard L.

2013-01-01

Purpose To develop a reliable magnetic resonance elastography (MRE)-based method for measuring regional brain stiffness. Methods First, simulation studies were used to demonstrate how stiffness measurements can be biased by changes in brain morphometry, such as those due to atrophy. Adaptive postprocessing methods were created that significantly reduce the spatial extent of edge artifacts and eliminate atrophy-related bias. Second, a pipeline for regional brain stiffness measurement was developed and evaluated for test-retest reliability in 10 healthy control subjects. Results This technique indicates high test-retest repeatability with a typical coefficient of variation of less than 1% for global brain stiffness and less than 2% for the lobes of the brain and the cerebellum. Furthermore, this study reveals that the brain possesses a characteristic topography of mechanical properties, and also that lobar stiffness measurements tend to correlate with one another within an individual. Conclusion The methods presented in this work are resistant to noise- and edge-related biases that are common in the field of brain MRE, demonstrate high test-retest reliability, and provide independent regional stiffness measurements. This pipeline will allow future investigations to measure changes to the brain’s mechanical properties and how they relate to the characteristic topographies that are typical of many neurologic diseases. PMID:24312570

Recent advances in computational structural reliability analysis methods

NASA Astrophysics Data System (ADS)

Thacker, Ben H.; Wu, Y.-T.; Millwater, Harry R.; Torng, Tony Y.; Riha, David S.

1993-10-01

The goal of structural reliability analysis is to determine the probability that the structure will adequately perform its intended function when operating under the given environmental conditions. Thus, the notion of reliability admits the possibility of failure. Given the fact that many different modes of failure are usually possible, achievement of this goal is a formidable task, especially for large, complex structural systems. The traditional (deterministic) design methodology attempts to assure reliability by the application of safety factors and conservative assumptions. However, the safety factor approach lacks a quantitative basis in that the level of reliability is never known and usually results in overly conservative designs because of compounding conservatisms. Furthermore, problem parameters that control the reliability are not identified, nor their importance evaluated. A summary of recent advances in computational structural reliability assessment is presented. A significant level of activity in the research and development community was seen recently, much of which was directed towards the prediction of failure probabilities for single mode failures. The focus is to present some early results and demonstrations of advanced reliability methods applied to structural system problems. This includes structures that can fail as a result of multiple component failures (e.g., a redundant truss), or structural components that may fail due to multiple interacting failure modes (e.g., excessive deflection, resonate vibration, or creep rupture). From these results, some observations and recommendations are made with regard to future research needs.

Recent advances in computational structural reliability analysis methods

NASA Technical Reports Server (NTRS)

Thacker, Ben H.; Wu, Y.-T.; Millwater, Harry R.; Torng, Tony Y.; Riha, David S.

1993-01-01

The goal of structural reliability analysis is to determine the probability that the structure will adequately perform its intended function when operating under the given environmental conditions. Thus, the notion of reliability admits the possibility of failure. Given the fact that many different modes of failure are usually possible, achievement of this goal is a formidable task, especially for large, complex structural systems. The traditional (deterministic) design methodology attempts to assure reliability by the application of safety factors and conservative assumptions. However, the safety factor approach lacks a quantitative basis in that the level of reliability is never known and usually results in overly conservative designs because of compounding conservatisms. Furthermore, problem parameters that control the reliability are not identified, nor their importance evaluated. A summary of recent advances in computational structural reliability assessment is presented. A significant level of activity in the research and development community was seen recently, much of which was directed towards the prediction of failure probabilities for single mode failures. The focus is to present some early results and demonstrations of advanced reliability methods applied to structural system problems. This includes structures that can fail as a result of multiple component failures (e.g., a redundant truss), or structural components that may fail due to multiple interacting failure modes (e.g., excessive deflection, resonate vibration, or creep rupture). From these results, some observations and recommendations are made with regard to future research needs.

Validation of highly reliable, real-time knowledge-based systems

NASA Technical Reports Server (NTRS)

Johnson, Sally C.

1988-01-01

Knowledge-based systems have the potential to greatly increase the capabilities of future aircraft and spacecraft and to significantly reduce support manpower needed for the space station and other space missions. However, a credible validation methodology must be developed before knowledge-based systems can be used for life- or mission-critical applications. Experience with conventional software has shown that the use of good software engineering techniques and static analysis tools can greatly reduce the time needed for testing and simulation of a system. Since exhaustive testing is infeasible, reliability must be built into the software during the design and implementation phases. Unfortunately, many of the software engineering techniques and tools used for conventional software are of little use in the development of knowledge-based systems. Therefore, research at Langley is focused on developing a set of guidelines, methods, and prototype validation tools for building highly reliable, knowledge-based systems. The use of a comprehensive methodology for building highly reliable, knowledge-based systems should significantly decrease the time needed for testing and simulation. A proven record of delivering reliable systems at the beginning of the highly visible testing and simulation phases is crucial to the acceptance of knowledge-based systems in critical applications.

IDHEAS – A NEW APPROACH FOR HUMAN RELIABILITY ANALYSIS

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

G. W. Parry; J.A Forester; V.N. Dang

2013-09-01

This paper describes a method, IDHEAS (Integrated Decision-Tree Human Event Analysis System) that has been developed jointly by the US NRC and EPRI as an improved approach to Human Reliability Analysis (HRA) that is based on an understanding of the cognitive mechanisms and performance influencing factors (PIFs) that affect operator responses. The paper describes the various elements of the method, namely the performance of a detailed cognitive task analysis that is documented in a crew response tree (CRT), and the development of the associated time-line to identify the critical tasks, i.e. those whose failure results in a human failure eventmore » (HFE), and an approach to quantification that is based on explanations of why the HFE might occur.« less

Application of a spectrally filtered probing light beam and RGB decomposition of microphotographs for flow registration of ultrasonically enhanced agglutination of erythrocytes

NASA Astrophysics Data System (ADS)

Doubrovski, V. A.; Ganilova, Yu. A.; Zabenkov, I. V.

2013-08-01

We propose a development of the flow microscopy method to increase the resolving power upon registration of erythrocyte agglutination. We experimentally show that the action of a ultrasonic standing wave on an agglutinating mixture blood-serum leads to the formation of so large erythrocytic immune complexes that it seems possible to propose a new two-wave optical method of registration of the process of erythrocyte agglutination using the RGB decomposition of microphotographs of the flow of the mixture under study. This approach increases the reliability of registration of erythrocyte agglutination and, consequently, increases the reliability of blood typing. Our results can be used in the development of instruments for automatic human blood typing.

NDE reliability and probability of detection (POD) evolution and paradigm shift

NASA Astrophysics Data System (ADS)

Singh, Surendra

2014-02-01

The subject of NDE Reliability and POD has gone through multiple phases since its humble beginning in the late 1960s. This was followed by several programs including the important one nicknamed "Have Cracks - Will Travel" or in short "Have Cracks" by Lockheed Georgia Company for US Air Force during 1974-1978. This and other studies ultimately led to a series of developments in the field of reliability and POD starting from the introduction of fracture mechanics and Damaged Tolerant Design (DTD) to statistical framework by Bernes and Hovey in 1981 for POD estimation to MIL-STD HDBK 1823 (1999) and 1823A (2009). During the last decade, various groups and researchers have further studied the reliability and POD using Model Assisted POD (MAPOD), Simulation Assisted POD (SAPOD), and applying Bayesian Statistics. All and each of these developments had one objective, i.e., improving accuracy of life prediction in components that to a large extent depends on the reliability and capability of NDE methods. Therefore, it is essential to have a reliable detection and sizing of large flaws in components. Currently, POD is used for studying reliability and capability of NDE methods, though POD data offers no absolute truth regarding NDE reliability, i.e., system capability, effects of flaw morphology, and quantifying the human factors. Furthermore, reliability and POD have been reported alike in meaning but POD is not NDE reliability. POD is a subset of the reliability that consists of six phases: 1) samples selection using DOE, 2) NDE equipment setup and calibration, 3) System Measurement Evaluation (SME) including Gage Repeatability &Reproducibility (Gage R&R) and Analysis Of Variance (ANOVA), 4) NDE system capability and electronic and physical saturation, 5) acquiring and fitting data to a model, and data analysis, and 6) POD estimation. This paper provides an overview of all major POD milestones for the last several decades and discuss rationale for using Integrated Computational Materials Engineering (ICME), MAPOD, SAPOD, and Bayesian statistics for studying controllable and non-controllable variables including human factors for estimating POD. Another objective is to list gaps between "hoped for" versus validated or fielded failed hardware.

Defining new dental phenotypes using 3-D image analysis to enhance discrimination and insights into biological processes

PubMed Central

Smith, Richard; Zaitoun, Halla; Coxon, Tom; Karmo, Mayada; Kaur, Gurpreet; Townsend, Grant; Harris, Edward F.; Brook, Alan

2009-01-01

Aims In studying aetiological interactions of genetic, epigenetic and environmental factors in normal and abnormal developments of the dentition, methods of measurement have often been limited to maximum mesio-distal and bucco-lingual crown diameters, obtained with hand-held calipers. While this approach has led to many important findings, there are potentially many other informative measurements that can be made to describe dental crown morphology. Advances in digital imaging and computer technology now offer the opportunity to define and measure new dental phenotypes in 3-D that have the potential to provide better anatomical discrimination and clearer insights into the underlying biological processes in dental development. Over recent years, image analysis in 2-D has proved to be a valuable addition to hand-measurement methods but a reliable and rapid 3-D method would increase greatly the morphological information obtainable from natural teeth and dental models. Additional measurements such as crown heights, surface contours, actual surface perimeters and areas, and tooth volumes would maximise our ability to discriminate between samples and to explore more deeply genetic and environmental contributions to observed variation. The research objectives were to investigate the limitations of existing methodologies and to develop and validate new methods for obtaining true 3-D measurements, including curvatures and volumes, in order to enhance discrimination to allow increased differentiation in studies of dental morphology and development. The validity of a new methodology for the 3-D measurement of teeth is compared against an established 2-D system. The intra- and inter-observer reliability of some additional measurements, made possible with a 3-D approach, are also tested. Methods and results From each of 20 study models, the permanent upper right lateral and upper left central incisors were separated and imaged independently by two operators using 2-D image analysis and a 3-D image analysis system. The mesio-distal (MD), labio-lingual (LL) and inciso-gingival (IG) dimensions were recorded using our 2-D system and the same projected variables were also recorded using a newly developed 3-D system for comparison. Values of Pearson's correlation coefficient between measurements obtained using the two techniques were significant at the 0.01 probability level for variables mesio-distal and incisal-gingival with labio-lingual significant at the 0.05 level for the upper left side only, confirming their comparability. For both 2-D and 3-D systems the intra- and inter-operator reliability was substantial or excellent for variables mesio-distal, labio-lingual, incisal-gingival actual and projected and actual surface area. The reliability was good for inter-operator reliability measurement of the labio-lingual dimension using 3-D. Conclusions We have developed a new 3-D laser scanning system that enables additional dental phenotypes to be defined. It has been validated against an established 2-D system and shown to provide measurements with excellent reliability, both within and between operators. This new approach provides exciting possibilities for exploring normal and abnormal variations in dental morphology and development applicable to research on genetic and environmental factors. PMID:18644585

A systematic review of reliability and objective criterion-related validity of physical activity questionnaires.

PubMed

Helmerhorst, Hendrik J F; Brage, Søren; Warren, Janet; Besson, Herve; Ekelund, Ulf

2012-08-31

Physical inactivity is one of the four leading risk factors for global mortality. Accurate measurement of physical activity (PA) and in particular by physical activity questionnaires (PAQs) remains a challenge. The aim of this paper is to provide an updated systematic review of the reliability and validity characteristics of existing and more recently developed PAQs and to quantitatively compare the performance between existing and newly developed PAQs.A literature search of electronic databases was performed for studies assessing reliability and validity data of PAQs using an objective criterion measurement of PA between January 1997 and December 2011. Articles meeting the inclusion criteria were screened and data were extracted to provide a systematic overview of measurement properties. Due to differences in reported outcomes and criterion methods a quantitative meta-analysis was not possible.In total, 31 studies testing 34 newly developed PAQs, and 65 studies examining 96 existing PAQs were included. Very few PAQs showed good results on both reliability and validity. Median reliability correlation coefficients were 0.62-0.71 for existing, and 0.74-0.76 for new PAQs. Median validity coefficients ranged from 0.30-0.39 for existing, and from 0.25-0.41 for new PAQs.Although the majority of PAQs appear to have acceptable reliability, the validity is moderate at best. Newly developed PAQs do not appear to perform substantially better than existing PAQs in terms of reliability and validity. Future PAQ studies should include measures of absolute validity and the error structure of the instrument.

A systematic review of reliability and objective criterion-related validity of physical activity questionnaires

PubMed Central

2012-01-01

Physical inactivity is one of the four leading risk factors for global mortality. Accurate measurement of physical activity (PA) and in particular by physical activity questionnaires (PAQs) remains a challenge. The aim of this paper is to provide an updated systematic review of the reliability and validity characteristics of existing and more recently developed PAQs and to quantitatively compare the performance between existing and newly developed PAQs. A literature search of electronic databases was performed for studies assessing reliability and validity data of PAQs using an objective criterion measurement of PA between January 1997 and December 2011. Articles meeting the inclusion criteria were screened and data were extracted to provide a systematic overview of measurement properties. Due to differences in reported outcomes and criterion methods a quantitative meta-analysis was not possible. In total, 31 studies testing 34 newly developed PAQs, and 65 studies examining 96 existing PAQs were included. Very few PAQs showed good results on both reliability and validity. Median reliability correlation coefficients were 0.62–0.71 for existing, and 0.74–0.76 for new PAQs. Median validity coefficients ranged from 0.30–0.39 for existing, and from 0.25–0.41 for new PAQs. Although the majority of PAQs appear to have acceptable reliability, the validity is moderate at best. Newly developed PAQs do not appear to perform substantially better than existing PAQs in terms of reliability and validity. Future PAQ studies should include measures of absolute validity and the error structure of the instrument. PMID:22938557

Method Development in Forensic Toxicology.

PubMed

Peters, Frank T; Wissenbach, Dirk K; Busardo, Francesco Paolo; Marchei, Emilia; Pichini, Simona

2017-01-01

In the field of forensic toxicology, the quality of analytical methods is of great importance to ensure the reliability of results and to avoid unjustified legal consequences. A key to high quality analytical methods is a thorough method development. The presented article will provide an overview on the process of developing methods for forensic applications. This includes the definition of the method's purpose (e.g. qualitative vs quantitative) and the analytes to be included, choosing an appropriate sample matrix, setting up separation and detection systems as well as establishing a versatile sample preparation. Method development is concluded by an optimization process after which the new method is subject to method validation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Integration of Human Reliability Analysis Models into the Simulation-Based Framework for the Risk-Informed Safety Margin Characterization Toolkit

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

Boring, Ronald; Mandelli, Diego; Rasmussen, Martin

2016-06-01

This report presents an application of a computation-based human reliability analysis (HRA) framework called the Human Unimodel for Nuclear Technology to Enhance Reliability (HUNTER). HUNTER has been developed not as a standalone HRA method but rather as framework that ties together different HRA methods to model dynamic risk of human activities as part of an overall probabilistic risk assessment (PRA). While we have adopted particular methods to build an initial model, the HUNTER framework is meant to be intrinsically flexible to new pieces that achieve particular modeling goals. In the present report, the HUNTER implementation has the following goals: •more » Integration with a high fidelity thermal-hydraulic model capable of modeling nuclear power plant behaviors and transients • Consideration of a PRA context • Incorporation of a solid psychological basis for operator performance • Demonstration of a functional dynamic model of a plant upset condition and appropriate operator response This report outlines these efforts and presents the case study of a station blackout scenario to demonstrate the various modules developed to date under the HUNTER research umbrella.« less

Scientific Inquiry Competency Perception Scale (The Case of Kazak Post-Graduate Students) Reliability and Validity Study

ERIC Educational Resources Information Center

Gelisli, Yücel; Beisenbayeva, Lyazzat

2017-01-01

The purpose of the current study is to develop a reliable scale to be used to determine the scientific inquiry competency perception of post-graduate students engaged in post-graduate studies in the field of educational sciences and teacher education in Kazakhstan. The study employed the descriptive method. Within the context of the study, a scale…

Reliable aerial thermography for energy conservation

NASA Technical Reports Server (NTRS)

Jack, J. R.; Bowman, R. L.

1981-01-01

A method for energy conservation, the aerial thermography survey, is discussed. It locates sources of energy losses and wasteful energy management practices. An operational map is presented for clear sky conditions. The map outlines the key environmental conditions conductive to obtaining reliable aerial thermography. The map is developed from defined visual and heat loss discrimination criteria which are quantized based on flat roof heat transfer calculations.

Pediatric Quality of Life Enjoyment and Satisfaction Questionnaire (PQ-LES-Q): Reliability and Validity

ERIC Educational Resources Information Center

Endicott, Jean; Nee, John; Yang, Ruoyong; Wohlberg, Christopher

2006-01-01

Objective: The pediatric version of the Short Form of the Quality of Life Enjoyment and Satisfaction Questionnaire (PQ-LES-Q) was developed to aid in the assessment of an important aspect of life experience in children and adolescents. Method: The reliability and validity of the PQ-LES-Q was tested using data from a sample of 376 outpatient…

An overview of computational simulation methods for composite structures failure and life analysis

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

1993-01-01

Three parallel computational simulation methods are being developed at the LeRC Structural Mechanics Branch (SMB) for composite structures failure and life analysis: progressive fracture CODSTRAN; hierarchical methods for high-temperature composites; and probabilistic evaluation. Results to date demonstrate that these methods are effective in simulating composite structures failure/life/reliability.

Analysis of health trait data from on-farm computer systems in the U.S. II: Comparison of genomic analyses including two-stage and single-step methods

USDA-ARS?s Scientific Manuscript database

The development of genomic selection methodology, with accompanying substantial gains in reliability for low-heritability traits, may dramatically improve the feasibility of genetic improvement of dairy cow health. Many methods for genomic analysis have now been developed, including the “Bayesian Al...

Validation of an Instrument to Measure High School Students' Attitudes toward Fitness Testing

ERIC Educational Resources Information Center

Mercier, Kevin; Silverman, Stephen

2014-01-01

Purpose: The purpose of this investigation was to develop an instrument that has scores that are valid and reliable for measuring students' attitudes toward fitness testing. Method: The method involved the following steps: (a) an elicitation study, (b) item development, (c) a pilot study, and (d) a validation study. The pilot study included 427…

Methods for determining time of death.

PubMed

Madea, Burkhard

2016-12-01

Medicolegal death time estimation must estimate the time since death reliably. Reliability can only be provided empirically by statistical analysis of errors in field studies. Determining the time since death requires the calculation of measurable data along a time-dependent curve back to the starting point. Various methods are used to estimate the time since death. The current gold standard for death time estimation is a previously established nomogram method based on the two-exponential model of body cooling. Great experimental and practical achievements have been realized using this nomogram method. To reduce the margin of error of the nomogram method, a compound method was developed based on electrical and mechanical excitability of skeletal muscle, pharmacological excitability of the iris, rigor mortis, and postmortem lividity. Further increasing the accuracy of death time estimation involves the development of conditional probability distributions for death time estimation based on the compound method. Although many studies have evaluated chemical methods of death time estimation, such methods play a marginal role in daily forensic practice. However, increased precision of death time estimation has recently been achieved by considering various influencing factors (i.e., preexisting diseases, duration of terminal episode, and ambient temperature). Putrefactive changes may be used for death time estimation in water-immersed bodies. Furthermore, recently developed technologies, such as H magnetic resonance spectroscopy, can be used to quantitatively study decompositional changes. This review addresses the gold standard method of death time estimation in forensic practice and promising technological and scientific developments in the field.

Reliability-based econometrics of aerospace structural systems: Design criteria and test options. Ph.D. Thesis - Georgia Inst. of Tech.

NASA Technical Reports Server (NTRS)

Thomas, J. M.; Hanagud, S.

1974-01-01

The design criteria and test options for aerospace structural reliability were investigated. A decision methodology was developed for selecting a combination of structural tests and structural design factors. The decision method involves the use of Bayesian statistics and statistical decision theory. Procedures are discussed for obtaining and updating data-based probabilistic strength distributions for aerospace structures when test information is available and for obtaining subjective distributions when data are not available. The techniques used in developing the distributions are explained.

An adaptive field detection method for bridge scour monitoring using motion-sensing radio transponders (RFIDs).

DOT National Transportation Integrated Search

2014-01-01

A comprehensive field detection method is proposed that is aimed at developing advanced capability for : reliable monitoring, inspection and life estimation of bridge infrastructure. The goal is to utilize Motion-Sensing Radio Transponders (RFIDS) on...

Development of Reliability Based Life Prediction Methods for Thermal and Environmental Barrier Coatings in Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Shah, Ashwin

2001-01-01

Literature survey related to the EBC/TBC (environmental barrier coating/thermal barrier coating) fife models, failure mechanisms in EBC/TBC and the initial work plan for the proposed EBC/TBC life prediction methods development was developed as well as the finite element model for the thermal/stress analysis of the GRC-developed EBC system was prepared. Technical report for these activities is given in the subsequent sections.

The reliability of multistory buildings with the effect of non-uniform settlements of foundation

NASA Astrophysics Data System (ADS)

Al'Malul, Rafik; Gadzhuntsev, Michail

2018-03-01

The issue is the evaluation of reliability of construction considering the influence of the variation of the support settlement, which is changing during the lifetime of constructions due to the consolidation process of the ground. Recently, the specialists give special emphasis to the necessity to develop the methods for the estimation of reliability and durability of structures. The problem, the article considers, is the determination of the reliability of multistory buildings with non-uniform changing-in-time sediments caused by the consolidation process in soils. Failure of structures may occur before the draft reaches it`s stabilizing value, because of the violations of the conditions of normal use.

Overcoming the Challenges of Unstructured Data in Multi-site, Electronic Medical Record-based Abstraction

PubMed Central

Polnaszek, Brock; Gilmore-Bykovskyi, Andrea; Hovanes, Melissa; Roiland, Rachel; Ferguson, Patrick; Brown, Roger; Kind, Amy JH

2014-01-01

Background Unstructured data encountered during retrospective electronic medical record (EMR) abstraction has routinely been identified as challenging to reliably abstract, as this data is often recorded as free text, without limitations to format or structure. There is increased interest in reliably abstracting this type of data given its prominent role in care coordination and communication, yet limited methodological guidance exists. Objective As standard abstraction approaches resulted in sub-standard data reliability for unstructured data elements collected as part of a multi-site, retrospective EMR study of hospital discharge communication quality, our goal was to develop, apply and examine the utility of a phase-based approach to reliably abstract unstructured data. This approach is examined using the specific example of discharge communication for warfarin management. Research Design We adopted a “fit-for-use” framework to guide the development and evaluation of abstraction methods using a four step, phase-based approach including (1) team building, (2) identification of challenges, (3) adaptation of abstraction methods, and (4) systematic data quality monitoring. Measures Unstructured data elements were the focus of this study, including elements communicating steps in warfarin management (e.g., warfarin initiation) and medical follow-up (e.g., timeframe for follow-up). Results After implementation of the phase-based approach, inter-rater reliability for all unstructured data elements demonstrated kappas of ≥ 0.89 -- an average increase of + 0.25 for each unstructured data element. Conclusions As compared to standard abstraction methodologies, this phase-based approach was more time intensive, but did markedly increase abstraction reliability for unstructured data elements within multi-site EMR documentation. PMID:27624585

The Arthroscopic Surgical Skill Evaluation Tool (ASSET).

PubMed

Koehler, Ryan J; Amsdell, Simon; Arendt, Elizabeth A; Bisson, Leslie J; Braman, Jonathan P; Bramen, Jonathan P; Butler, Aaron; Cosgarea, Andrew J; Harner, Christopher D; Garrett, William E; Olson, Tyson; Warme, Winston J; Nicandri, Gregg T

2013-06-01

Surgeries employing arthroscopic techniques are among the most commonly performed in orthopaedic clinical practice; however, valid and reliable methods of assessing the arthroscopic skill of orthopaedic surgeons are lacking. The Arthroscopic Surgery Skill Evaluation Tool (ASSET) will demonstrate content validity, concurrent criterion-oriented validity, and reliability when used to assess the technical ability of surgeons performing diagnostic knee arthroscopic surgery on cadaveric specimens. Cross-sectional study; Level of evidence, 3. Content validity was determined by a group of 7 experts using the Delphi method. Intra-articular performance of a right and left diagnostic knee arthroscopic procedure was recorded for 28 residents and 2 sports medicine fellowship-trained attending surgeons. Surgeon performance was assessed by 2 blinded raters using the ASSET. Concurrent criterion-oriented validity, interrater reliability, and test-retest reliability were evaluated. Content validity: The content development group identified 8 arthroscopic skill domains to evaluate using the ASSET. Concurrent criterion-oriented validity: Significant differences in the total ASSET score (P < .05) between novice, intermediate, and advanced experience groups were identified. Interrater reliability: The ASSET scores assigned by each rater were strongly correlated (r = 0.91, P < .01), and the intraclass correlation coefficient between raters for the total ASSET score was 0.90. Test-retest reliability: There was a significant correlation between ASSET scores for both procedures attempted by each surgeon (r = 0.79, P < .01). The ASSET appears to be a useful, valid, and reliable method for assessing surgeon performance of diagnostic knee arthroscopic surgery in cadaveric specimens. Studies are ongoing to determine its generalizability to other procedures as well as to the live operating room and other simulated environments.

An Early Years Toolbox for Assessing Early Executive Function, Language, Self-Regulation, and Social Development: Validity, Reliability, and Preliminary Norms

PubMed Central

Howard, Steven J.; Melhuish, Edward

2016-01-01

Several methods of assessing executive function (EF), self-regulation, language development, and social development in young children have been developed over previous decades. Yet new technologies make available methods of assessment not previously considered. In resolving conceptual and pragmatic limitations of existing tools, the Early Years Toolbox (EYT) offers substantial advantages for early assessment of language, EF, self-regulation, and social development. In the current study, results of our large-scale administration of this toolbox to 1,764 preschool and early primary school students indicated very good reliability, convergent validity with existing measures, and developmental sensitivity. Results were also suggestive of better capture of children’s emerging abilities relative to comparison measures. Preliminary norms are presented, showing a clear developmental trajectory across half-year age groups. The accessibility of the EYT, as well as its advantages over existing measures, offers considerably enhanced opportunities for objective measurement of young children’s abilities to enable research and educational applications. PMID:28503022

MEASURING SPORT-SPECIFIC PHYSICAL ABILITIES IN MALE GYMNASTS: THE MEN'S GYMNASTICS FUNCTIONAL MEASUREMENT TOOL

PubMed Central

Kenyon, Lisa K.; Elliott, James M; Cheng, M. Samuel

2016-01-01

Purpose/Background Despite the availability of various field-tests for many competitive sports, a reliable and valid test specifically developed for use in men's gymnastics has not yet been developed. The Men's Gymnastics Functional Measurement Tool (MGFMT) was designed to assess sport-specific physical abilities in male competitive gymnasts. The purpose of this study was to develop the MGFMT by establishing a scoring system for individual test items and to initiate the process of establishing test-retest reliability and construct validity. Methods A total of 83 competitive male gymnasts ages 7-18 underwent testing using the MGFMT. Thirty of these subjects underwent re-testing one week later in order to assess test-retest reliability. Construct validity was assessed using a simple regression analysis between total MGFMT scores and the gymnasts’ USA-Gymnastics competitive level to calculate the coefficient of determination (r2). Test-retest reliability was analyzed using Model 1 Intraclass correlation coefficients (ICC). Statistical significance was set at the p<0.05 level. Results The relationship between total MGFMT scores and subjects’ current USA-Gymnastics competitive level was found to be good (r2 = 0.63). Reliability testing of the MGFMT composite test score showed excellent test-retest reliability over a one-week period (ICC = 0.97). Test-retest reliability of the individual component tests ranged from good to excellent (ICC = 0.75-0.97). Conclusions The results of this study provide initial support for the construct validity and test-retest reliability of the MGFMT. Level of Evidence Level 3 PMID:27999723

Probabilistic structural mechanics research for parallel processing computers

NASA Technical Reports Server (NTRS)

Sues, Robert H.; Chen, Heh-Chyun; Twisdale, Lawrence A.; Martin, William R.

1991-01-01

Aerospace structures and spacecraft are a complex assemblage of structural components that are subjected to a variety of complex, cyclic, and transient loading conditions. Significant modeling uncertainties are present in these structures, in addition to the inherent randomness of material properties and loads. To properly account for these uncertainties in evaluating and assessing the reliability of these components and structures, probabilistic structural mechanics (PSM) procedures must be used. Much research has focused on basic theory development and the development of approximate analytic solution methods in random vibrations and structural reliability. Practical application of PSM methods was hampered by their computationally intense nature. Solution of PSM problems requires repeated analyses of structures that are often large, and exhibit nonlinear and/or dynamic response behavior. These methods are all inherently parallel and ideally suited to implementation on parallel processing computers. New hardware architectures and innovative control software and solution methodologies are needed to make solution of large scale PSM problems practical.

Testing the reliability and efficiency of the pilot Mixed Methods Appraisal Tool (MMAT) for systematic mixed studies review.

PubMed

Pace, Romina; Pluye, Pierre; Bartlett, Gillian; Macaulay, Ann C; Salsberg, Jon; Jagosh, Justin; Seller, Robbyn

2012-01-01

Systematic literature reviews identify, select, appraise, and synthesize relevant literature on a particular topic. Typically, these reviews examine primary studies based on similar methods, e.g., experimental trials. In contrast, interest in a new form of review, known as mixed studies review (MSR), which includes qualitative, quantitative, and mixed methods studies, is growing. In MSRs, reviewers appraise studies that use different methods allowing them to obtain in-depth answers to complex research questions. However, appraising the quality of studies with different methods remains challenging. To facilitate systematic MSRs, a pilot Mixed Methods Appraisal Tool (MMAT) has been developed at McGill University (a checklist and a tutorial), which can be used to concurrently appraise the methodological quality of qualitative, quantitative, and mixed methods studies. The purpose of the present study is to test the reliability and efficiency of a pilot version of the MMAT. The Center for Participatory Research at McGill conducted a systematic MSR on the benefits of Participatory Research (PR). Thirty-two PR evaluation studies were appraised by two independent reviewers using the pilot MMAT. Among these, 11 (34%) involved nurses as researchers or research partners. Appraisal time was measured to assess efficiency. Inter-rater reliability was assessed by calculating a kappa statistic based on dichotomized responses for each criterion. An appraisal score was determined for each study, which allowed the calculation of an overall intra-class correlation. On average, it took 14 min to appraise a study (excluding the initial reading of articles). Agreement between reviewers was moderate to perfect with regards to MMAT criteria, and substantial with respect to the overall quality score of appraised studies. The MMAT is unique, thus the reliability of the pilot MMAT is promising, and encourages further development. Copyright © 2011 Elsevier Ltd. All rights reserved.

A Method for Analyzing the Coherence of High School Biology Textbooks

ERIC Educational Resources Information Center

Roseman, Jo Ellen; Stern, Luli; Koppal, Mary

2010-01-01

Because textbooks have the potential to be powerful catalysts for improving science teaching and learning, having reliable methods for analyzing important textbook features, such as their coherence, is essential. This study reports on the development of a method in which trained reviewers, following a set of guidelines defining the ideas to be…

Reliability of proton NMR spectroscopy for the assessment of frying oil oxidation

USDA-ARS?s Scientific Manuscript database

Although there are many analytical methods developed to assess oxidation of edible oil, it is still common to see a lack of consistency in results from different methods. This inconsistency is expected since there are numerous oxidation products and any analytical method measuring only one kind of o...

The NMR analysis of frying oil: a very reliable method for assessment of lipid oxidation

USDA-ARS?s Scientific Manuscript database

There are many analytical methods developed for the assessment of lipid oxidation. However, one of the most challenging issues in analyzing oil oxidation is that there is lack of consistency in results obtained from different analytical methods. The major reason for the inconsistency is that most me...

A method of estimating the knock rating of hydrocarbon fuel blend

NASA Technical Reports Server (NTRS)

Sanders, Newell D

1943-01-01

The usefulness of the knock ratings of pure hydrocarbon compounds would be increased if some reliable method of calculating the knock ratings of fuel blends was known. The purpose of this study was to investigate the possibility of developing a method of predicting the knock ratings of fuel blends.

A Method of Estimating the Knock Rating of Hydrocarbon Fuel Blends

NASA Technical Reports Server (NTRS)

Sanders, Newell D.

1943-01-01

The usefulness of the knock ratings of pure hydrocarbon compounds would be increased if some reliable method of calculating the knock ratings of fuel blends was known. The purpose of this study was to investigate the possibility of developing a method of predicting the knock ratings of fuel blends.

Very Large Scale Optimization

NASA Technical Reports Server (NTRS)

Vanderplaats, Garrett; Townsend, James C. (Technical Monitor)

2002-01-01

The purpose of this research under the NASA Small Business Innovative Research program was to develop algorithms and associated software to solve very large nonlinear, constrained optimization tasks. Key issues included efficiency, reliability, memory, and gradient calculation requirements. This report describes the general optimization problem, ten candidate methods, and detailed evaluations of four candidates. The algorithm chosen for final development is a modern recreation of a 1960s external penalty function method that uses very limited computer memory and computational time. Although of lower efficiency, the new method can solve problems orders of magnitude larger than current methods. The resulting BIGDOT software has been demonstrated on problems with 50,000 variables and about 50,000 active constraints. For unconstrained optimization, it has solved a problem in excess of 135,000 variables. The method includes a technique for solving discrete variable problems that finds a "good" design, although a theoretical optimum cannot be guaranteed. It is very scalable in that the number of function and gradient evaluations does not change significantly with increased problem size. Test cases are provided to demonstrate the efficiency and reliability of the methods and software.

Probabilistic framework for product design optimization and risk management

NASA Astrophysics Data System (ADS)

Keski-Rahkonen, J. K.

2018-05-01

Probabilistic methods have gradually gained ground within engineering practices but currently it is still the industry standard to use deterministic safety margin approaches to dimensioning components and qualitative methods to manage product risks. These methods are suitable for baseline design work but quantitative risk management and product reliability optimization require more advanced predictive approaches. Ample research has been published on how to predict failure probabilities for mechanical components and furthermore to optimize reliability through life cycle cost analysis. This paper reviews the literature for existing methods and tries to harness their best features and simplify the process to be applicable in practical engineering work. Recommended process applies Monte Carlo method on top of load-resistance models to estimate failure probabilities. Furthermore, it adds on existing literature by introducing a practical framework to use probabilistic models in quantitative risk management and product life cycle costs optimization. The main focus is on mechanical failure modes due to the well-developed methods used to predict these types of failures. However, the same framework can be applied on any type of failure mode as long as predictive models can be developed.

Probabilistic Parameter Uncertainty Analysis of Single Input Single Output Control Systems

NASA Technical Reports Server (NTRS)

Smith, Brett A.; Kenny, Sean P.; Crespo, Luis G.

2005-01-01

The current standards for handling uncertainty in control systems use interval bounds for definition of the uncertain parameters. This approach gives no information about the likelihood of system performance, but simply gives the response bounds. When used in design, current methods of m-analysis and can lead to overly conservative controller design. With these methods, worst case conditions are weighted equally with the most likely conditions. This research explores a unique approach for probabilistic analysis of control systems. Current reliability methods are examined showing the strong areas of each in handling probability. A hybrid method is developed using these reliability tools for efficiently propagating probabilistic uncertainty through classical control analysis problems. The method developed is applied to classical response analysis as well as analysis methods that explore the effects of the uncertain parameters on stability and performance metrics. The benefits of using this hybrid approach for calculating the mean and variance of responses cumulative distribution functions are shown. Results of the probabilistic analysis of a missile pitch control system, and a non-collocated mass spring system, show the added information provided by this hybrid analysis.

Development and validation of a German version of the joint protection behavior assessment in patients with rheumatoid arthritis.

PubMed

Niedermann, K; Forster, A; Hammond, A; Uebelhart, D; de Bie, R

2007-03-15

Joint protection (JP) is an important part of the treatment concept for patients with rheumatoid arthritis (RA). The Joint Protection Behavior Assessment short form (JPBA-S) assesses the use of hand JP methods by patients with RA while preparing a hot drink. The purpose of this study was to develop a German version of the JPBA-S (D-JPBA-S) and to test its validity and reliability. A manual was developed through consensus with 8 occupational therapist (OT) experts as the reference for assessing patients' JP behavior. Twenty-four patients with RA and 10 healthy individuals were videotaped while performing 10 tasks reflecting the activity of preparing instant coffee. Recordings were repeated after 3 months for test-retest analysis. One rater assessed all available patient recordings (n = 23, recorded twice) for test-retest reliability. The video recordings of 10 randomly selected patients and all healthy individuals were independently assessed for interrater reliability by 6 OTs who were explicitly asked to follow the manual. Rasch analysis was performed to test construct validity and transform ordinal raw data into interval data for reliability calculations. Nine of the 10 tasks fit the Rasch model. The D-JPBA-S, consisting of 9 valid tasks, had an intraclass correlation coefficient of 0.77 for interrater reliability and 0.71 for test-retest reliability. The D-JPBA-S provides a valid and reliable instrument for assessing JP behavior of patients with RA and can be used in German-speaking countries.

PROOF OF CONCEPT FOR A HUMAN RELIABILITY ANALYSIS METHOD FOR HEURISTIC USABILITY EVALUATION OF SOFTWARE

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

Ronald L. Boring; David I. Gertman; Jeffrey C. Joe

2005-09-01

An ongoing issue within human-computer interaction (HCI) is the need for simplified or “discount” methods. The current economic slowdown has necessitated innovative methods that are results driven and cost effective. The myriad methods of design and usability are currently being cost-justified, and new techniques are actively being explored that meet current budgets and needs. Recent efforts in human reliability analysis (HRA) are highlighted by the ten-year development of the Standardized Plant Analysis Risk HRA (SPAR-H) method. The SPAR-H method has been used primarily for determining humancentered risk at nuclear power plants. The SPAR-H method, however, shares task analysis underpinnings withmore » HCI. Despite this methodological overlap, there is currently no HRA approach deployed in heuristic usability evaluation. This paper presents an extension of the existing SPAR-H method to be used as part of heuristic usability evaluation in HCI.« less

Construction of reliable protein-protein interaction networks with a new interaction generality measure.

PubMed

Saito, Rintaro; Suzuki, Harukazu; Hayashizaki, Yoshihide

2003-04-12

Recent screening techniques have made large amounts of protein-protein interaction data available, from which biologically important information such as the function of uncharacterized proteins, the existence of novel protein complexes, and novel signal-transduction pathways can be discovered. However, experimental data on protein interactions contain many false positives, making these discoveries difficult. Therefore computational methods of assessing the reliability of each candidate protein-protein interaction are urgently needed. We developed a new 'interaction generality' measure (IG2) to assess the reliability of protein-protein interactions using only the topological properties of their interaction-network structure. Using yeast protein-protein interaction data, we showed that reliable protein-protein interactions had significantly lower IG2 values than less-reliable interactions, suggesting that IG2 values can be used to evaluate and filter interaction data to enable the construction of reliable protein-protein interaction networks.

Internal Consistency, Retest Reliability, and their Implications For Personality Scale Validity

PubMed Central

McCrae, Robert R.; Kurtz, John E.; Yamagata, Shinji; Terracciano, Antonio

2010-01-01

We examined data (N = 34,108) on the differential reliability and validity of facet scales from the NEO Inventories. We evaluated the extent to which (a) psychometric properties of facet scales are generalizable across ages, cultures, and methods of measurement; and (b) validity criteria are associated with different forms of reliability. Composite estimates of facet scale stability, heritability, and cross-observer validity were broadly generalizable. Two estimates of retest reliability were independent predictors of the three validity criteria; none of three estimates of internal consistency was. Available evidence suggests the same pattern of results for other personality inventories. Internal consistency of scales can be useful as a check on data quality, but appears to be of limited utility for evaluating the potential validity of developed scales, and it should not be used as a substitute for retest reliability. Further research on the nature and determinants of retest reliability is needed. PMID:20435807

Force-length relationship in the pelvic floor muscles under transverse vaginal distension: a method study in healthy women.

PubMed

Verelst, M; Leivseth, G

2004-01-01

The purpose of this study was to investigate whether there is a relationship between changes in the diameter of the urogenital hiatus and force developed in pelvic floor musculature. In addition, we wanted to examine the reliability of the method that measures force development in the pelvic floor in the transverse direction of the urogenital hiatus. Passive and total force in the pelvic floor was measured with an intra-vaginal device in 20 healthy parous volunteers. The measurements were done with a consecutively increasing diameter in the transverse plane of the urogenital hiatus. The procedure was repeated with a few days interval. The measurements show an increase in force with an increasing device-diameter. The results are reliable at all the diameters tested, estimated by the within-subject day-to-day variability which was non-significant. The 40 mm diameter device is most favourable, estimated by Bland Altman plots of the test-retest measurements. Force development in pelvic floor muscles increased as a function of vaginal diameter when measured in the frontal plane. The measurements were reliable at all the different diameters chosen. 2004 Wiley-Liss, Inc.

Multidisciplinary System Reliability Analysis

NASA Technical Reports Server (NTRS)

Mahadevan, Sankaran; Han, Song; Chamis, Christos C. (Technical Monitor)

2001-01-01

The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code, developed under the leadership of NASA Glenn Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multidisciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

Multi-Disciplinary System Reliability Analysis

NASA Technical Reports Server (NTRS)

Mahadevan, Sankaran; Han, Song

1997-01-01

The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code developed under the leadership of NASA Lewis Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multi-disciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

Development and reliability of an observation method to assess food intake of young children in child care.

PubMed

Ball, Sarah C; Benjamin, Sara E; Ward, Dianne S

2007-04-01

To our knowledge, a direct observation protocol for assessing dietary intake among young children in child care has not been published. This article reviews the development and testing of a diet observation system for child care facilities that occurred during a larger intervention trial. Development of this system was divided into five phases, done in conjunction with a larger intervention study; (a) protocol development, (b) training of field staff, (c) certification of field staff in a laboratory setting, (d) implementation in a child-care setting, and (e) certification of field staff in a child-care setting. During the certification phases, methods were used to assess the accuracy and reliability of all observers at estimating types and amounts of food and beverages commonly served in child care. Tests of agreement show strong agreement among five observers, as well as strong accuracy between the observers and 20 measured portions of foods and beverages with a mean intraclass correlation coefficient value of 0.99. This structured observation system shows promise as a valid and reliable approach for assessing dietary intake of children in child care and makes a valuable contribution to the growing body of literature on the dietary assessment of young children.

Development and Evaluation of Example-Anchored Scales of Interpersonal Functioning for Rehabilitation Counseling Research.

ERIC Educational Resources Information Center

Richardson, Bill K.; And Others

There currently exists a clear need for counseling process research scales developed to reflect the specific behaviors unique to vocational rehabilitation counseling interviews. In research at the Menninger Foundation, Taylor developed methods for constructing example-anchored (EA) scales which increase rater reliability and decrease response…

Chemical imaging of secondary cell wall development in cotton fibers using a mid-infrared focal-plane array detector

USDA-ARS?s Scientific Manuscript database

Market demands for cotton varieties with improved fiber properties also call for the development of fast, reliable analytical methods for monitoring fiber development and measuring their properties. Currently, cotton breeders rely on instrumentation that can require significant amounts of sample, w...

Improving statistical inference on pathogen densities estimated by quantitative molecular methods: malaria gametocytaemia as a case study.

PubMed

Walker, Martin; Basáñez, María-Gloria; Ouédraogo, André Lin; Hermsen, Cornelus; Bousema, Teun; Churcher, Thomas S

2015-01-16

Quantitative molecular methods (QMMs) such as quantitative real-time polymerase chain reaction (q-PCR), reverse-transcriptase PCR (qRT-PCR) and quantitative nucleic acid sequence-based amplification (QT-NASBA) are increasingly used to estimate pathogen density in a variety of clinical and epidemiological contexts. These methods are often classified as semi-quantitative, yet estimates of reliability or sensitivity are seldom reported. Here, a statistical framework is developed for assessing the reliability (uncertainty) of pathogen densities estimated using QMMs and the associated diagnostic sensitivity. The method is illustrated with quantification of Plasmodium falciparum gametocytaemia by QT-NASBA. The reliability of pathogen (e.g. gametocyte) densities, and the accompanying diagnostic sensitivity, estimated by two contrasting statistical calibration techniques, are compared; a traditional method and a mixed model Bayesian approach. The latter accounts for statistical dependence of QMM assays run under identical laboratory protocols and permits structural modelling of experimental measurements, allowing precision to vary with pathogen density. Traditional calibration cannot account for inter-assay variability arising from imperfect QMMs and generates estimates of pathogen density that have poor reliability, are variable among assays and inaccurately reflect diagnostic sensitivity. The Bayesian mixed model approach assimilates information from replica QMM assays, improving reliability and inter-assay homogeneity, providing an accurate appraisal of quantitative and diagnostic performance. Bayesian mixed model statistical calibration supersedes traditional techniques in the context of QMM-derived estimates of pathogen density, offering the potential to improve substantially the depth and quality of clinical and epidemiological inference for a wide variety of pathogens.

Fatigue Reliability of Gas Turbine Engine Structures

NASA Technical Reports Server (NTRS)

Cruse, Thomas A.; Mahadevan, Sankaran; Tryon, Robert G.

1997-01-01

The results of an investigation are described for fatigue reliability in engine structures. The description consists of two parts. Part 1 is for method development. Part 2 is a specific case study. In Part 1, the essential concepts and practical approaches to damage tolerance design in the gas turbine industry are summarized. These have evolved over the years in response to flight safety certification requirements. The effect of Non-Destructive Evaluation (NDE) methods on these methods is also reviewed. Assessment methods based on probabilistic fracture mechanics, with regard to both crack initiation and crack growth, are outlined. Limit state modeling techniques from structural reliability theory are shown to be appropriate for application to this problem, for both individual failure mode and system-level assessment. In Part 2, the results of a case study for the high pressure turbine of a turboprop engine are described. The response surface approach is used to construct a fatigue performance function. This performance function is used with the First Order Reliability Method (FORM) to determine the probability of failure and the sensitivity of the fatigue life to the engine parameters for the first stage disk rim of the two stage turbine. A hybrid combination of regression and Monte Carlo simulation is to use incorporate time dependent random variables. System reliability is used to determine the system probability of failure, and the sensitivity of the system fatigue life to the engine parameters of the high pressure turbine. 'ne variation in the primary hot gas and secondary cooling air, the uncertainty of the complex mission loading, and the scatter in the material data are considered.

Development of high frequency low weight power magnetics for aerospace power systems

NASA Technical Reports Server (NTRS)

Schwarze, G. E.

1984-01-01

A dominant design consideration in the development of space type power mangetic devices is the application of reliable thermal control methods to prevent device failure which is due to excessive temperature rises and hot temperatures in critical areas. The resultant design must also yield low weight, high efficiency, high reliability and maintainability, and long life. The weight savings and high efficiency that results by going to high frequency and unique thermal control techniques is demonstrated by the development of a 25 kVA, 20 kHz space type transformer under the power magnetics technology program. Work in the area of power rotary transformer is also discussed.

78 FR 35038 - Proposed Information Collection Activity; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

..., reliable, and transparent method for identifying high-quality programs that can receive continuing five... the system is working. The study will employ a mixed-methods design that integrates and layers administrative and secondary data sources, observational measures, and interviews to develop a rich knowledge...

An algebraic equation solution process formulated in anticipation of banded linear equations.

DOT National Transportation Integrated Search

1971-01-01

A general method for the solution of large, sparsely banded, positive-definite, coefficient matrices is presented. The goal in developing the method was to produce an efficient and reliable solution process and to provide the user-programmer with a p...

Radiation-Tolerance Assessment of a Redundant Wireless Device

NASA Astrophysics Data System (ADS)

Huang, Q.; Jiang, J.

2018-01-01

This paper presents a method to evaluate radiation-tolerance without physical tests for a commercial off-the-shelf (COTS)-based monitoring device for high level radiation fields, such as those found in post-accident conditions in a nuclear power plant (NPP). This paper specifically describes the analysis of radiation environment in a severe accident, radiation damages in electronics, and the redundant solution used to prolong the life of the system, as well as the evaluation method for radiation protection and the analysis method of system reliability. As a case study, a wireless monitoring device with redundant and diversified channels is evaluated by using the developed method. The study results and system assessment data show that, under the given radiation condition, performance of the redundant device is more reliable and more robust than those non-redundant devices. The developed redundant wireless monitoring device is therefore able to apply in those conditions (up to 10 M Rad (Si)) during a severe accident in a NPP.

Optimal Bi-Objective Redundancy Allocation for Systems Reliability and Risk Management.

PubMed

Govindan, Kannan; Jafarian, Ahmad; Azbari, Mostafa E; Choi, Tsan-Ming

2016-08-01

In the big data era, systems reliability is critical to effective systems risk management. In this paper, a novel multiobjective approach, with hybridization of a known algorithm called NSGA-II and an adaptive population-based simulated annealing (APBSA) method is developed to solve the systems reliability optimization problems. In the first step, to create a good algorithm, we use a coevolutionary strategy. Since the proposed algorithm is very sensitive to parameter values, the response surface method is employed to estimate the appropriate parameters of the algorithm. Moreover, to examine the performance of our proposed approach, several test problems are generated, and the proposed hybrid algorithm and other commonly known approaches (i.e., MOGA, NRGA, and NSGA-II) are compared with respect to four performance measures: 1) mean ideal distance; 2) diversification metric; 3) percentage of domination; and 4) data envelopment analysis. The computational studies have shown that the proposed algorithm is an effective approach for systems reliability and risk management.

A scale space feature based registration technique for fusion of satellite imagery

NASA Technical Reports Server (NTRS)

Raghavan, Srini; Cromp, Robert F.; Campbell, William C.

1997-01-01

Feature based registration is one of the most reliable methods to register multi-sensor images (both active and passive imagery) since features are often more reliable than intensity or radiometric values. The only situation where a feature based approach will fail is when the scene is completely homogenous or densely textural in which case a combination of feature and intensity based methods may yield better results. In this paper, we present some preliminary results of testing our scale space feature based registration technique, a modified version of feature based method developed earlier for classification of multi-sensor imagery. The proposed approach removes the sensitivity in parameter selection experienced in the earlier version as explained later.

Validity of mail survey data on bagged waterfowl

USGS Publications Warehouse

Atwood, E.L.

1956-01-01

Knowledge of the pattern of occurrence and characteristics of response errors obtained during an investigation of the validity of post-season surveys of hunters was used to advantage to devise a two-step method for removing the response-bias errors from the raw survey data. The method was tested on data with known errors and found to have a high efficiency in reducing the effect of response-bias errors. The development of this method for removing the effect of the response-bias errors, and its application to post-season hunter-take survey data, increased the reliability of the data from below the point of practical management significance up to the approximate reliability limits corresponding to the sampling errors.

Development of performance test instrument in the experiment of law of conservation mass using self and peer assessment’s technique

NASA Astrophysics Data System (ADS)

Siswaningsih, W.; Nahadi; Firmansyah, D. R.

2018-05-01

The purpose of this research is to develop the instrument of performance assessment of law of mass conservation using self and peer assessment technique that meet valid and reliable criteria. The instrument components consist of task and rubric. The method used is development and validation.Value of the instrument reliability obtained from twice observations that are at four and six students every group with three same observers. Cronbach alpha value for four and six students every group consecutively are 0.94 and 0.76, indicating that value shows that the instrument is reliable. Optimum amount of the students that can be observed are four students. The implementation of the instrument to limited group of students showed that All of the students give positive responses to the instrument used with the interpretation of questionnaire scores >90% that categorized as good.

Simulated Surgery-an exam for our time? Summary of the current status and development of the MRCGP Simulated Surgery module.

PubMed

Hawthorne, Kamila; Denney, Mei Ling; Bewick, Mike; Wakeford, Richard

2006-01-01

WHAT IS ALREADY KNOWN IN THIS AREA • The Simulated Surgery module of the MRCGP examination has been shown to be a valid and reliable assessment of clinical consulting skills. WHAT THIS WORK ADDS • This paper describes the further development of the methodology of the Simulated Surgery; showing the type of data analysis currently used to assure its quality and reliability. The measures taken to tighten up case quality are discussed. SUGGESTIONS FOR FUTURE RESEARCH The future development of clinical skills assessments in general practice is discussed. More work is needed on the effectiveness and reliability of lay assessors in complex integrated clinical cases. New methods to test areas that are difficult to reproduces in a simulated environment (such as acute emergencies and cases with the very young or very old) are also needed.

Methods Used to Streamline the CAHPS® Hospital Survey

PubMed Central

Keller, San; O'Malley, A James; Hays, Ron D; Matthew, Rebecca A; Zaslavsky, Alan M; Hepner, Kimberly A; Cleary, Paul D

2005-01-01

Objective To identify a parsimonious subset of reliable, valid, and consumer-salient items from 33 questions asking for patient reports about hospital care quality. Data Source CAHPS® Hospital Survey pilot data were collected during the summer of 2003 using mail and telephone from 19,720 patients who had been treated in 132 hospitals in three states and discharged from November 2002 to January 2003. Methods Standard psychometric methods were used to assess the reliability (internal consistency reliability and hospital-level reliability) and construct validity (exploratory and confirmatory factor analyses, strength of relationship to overall rating of hospital) of the 33 report items. The best subset of items from among the 33 was selected based on their statistical properties in conjunction with the importance assigned to each item by participants in 14 focus groups. Principal Findings Confirmatory factor analysis (CFA) indicated that a subset of 16 questions proposed to measure seven aspects of hospital care (communication with nurses, communication with doctors, responsiveness to patient needs, physical environment, pain control, communication about medication, and discharge information) demonstrated excellent fit to the data. Scales in each of these areas had acceptable levels of reliability to discriminate among hospitals and internal consistency reliability estimates comparable with previously developed CAHPS instruments. Conclusion Although half the length of the original, the shorter CAHPS hospital survey demonstrates promising measurement properties, identifies variations in care among hospitals, and deals with aspects of the hospital stay that are important to patients' evaluations of care quality. PMID:16316438

Limit states and reliability-based pipeline design. Final report

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

Zimmerman, T.J.E.; Chen, Q.; Pandey, M.D.

1997-06-01

This report provides the results of a study to develop limit states design (LSD) procedures for pipelines. Limit states design, also known as load and resistance factor design (LRFD), provides a unified approach to dealing with all relevant failure modes combinations of concern. It explicitly accounts for the uncertainties that naturally occur in the determination of the loads which act on a pipeline and in the resistance of the pipe to failure. The load and resistance factors used are based on reliability considerations; however, the designer is not faced with carrying out probabilistic calculations. This work is done during developmentmore » and periodic updating of the LSD document. This report provides background information concerning limits states and reliability-based design (Section 2), gives the limit states design procedures that were developed (Section 3) and provides results of the reliability analyses that were undertaken in order to partially calibrate the LSD method (Section 4). An appendix contains LSD design examples in order to demonstrate use of the method. Section 3, Limit States Design has been written in the format of a recommended practice. It has been structured so that, in future, it can easily be converted to a limit states design code format. Throughout the report, figures and tables are given at the end of each section, with the exception of Section 3, where to facilitate understanding of the LSD method, they have been included with the text.« less

Nanoscale deformation measurements for reliability assessment of material interfaces

NASA Astrophysics Data System (ADS)

Keller, Jürgen; Gollhardt, Astrid; Vogel, Dietmar; Michel, Bernd

2006-03-01

With the development and application of micro/nano electronic mechanical systems (MEMS, NEMS) for a variety of market segments new reliability issues will arise. The understanding of material interfaces is the key for a successful design for reliability of MEMS/NEMS and sensor systems. Furthermore in the field of BIOMEMS newly developed advanced materials and well known engineering materials are combined despite of fully developed reliability concepts for such devices and components. In addition the increasing interface-to volume ratio in highly integrated systems and nanoparticle filled materials are challenges for experimental reliability evaluation. New strategies for reliability assessment on the submicron scale are essential to fulfil the needs of future devices. In this paper a nanoscale resolution experimental method for the measurement of thermo-mechanical deformation at material interfaces is introduced. The determination of displacement fields is based on scanning probe microscopy (SPM) data. In-situ SPM scans of the analyzed object (i.e. material interface) are carried out at different thermo-mechanical load states. The obtained images are compared by grayscale cross correlation algorithms. This allows the tracking of local image patterns of the analyzed surface structure. The measurement results are full-field displacement fields with nanometer resolution. With the obtained data the mixed mode type of loading at material interfaces can be analyzed with highest resolution for future needs in micro system and nanotechnology.

Development and testing of the questionnaire CEC-61: Knowledge about cervical cancer in Chilean adolescents.

PubMed

Urrutia, María Teresa; Gajardo, Macarena; Padilla, Oslando

2017-05-22

Despite a clear association between human papillomavirus and cervical cancer, knowledge in adolescent populations regarding the disease and methods for its detection and prevention is deficient. The aim of this study was to develop and test a new questionnaire concerning knowledge on cervical cancer. An instrument was developed and validated to measure knowledge in 226 Chilean adolescents between April and June 2011. Content validity, construct validity, and reliability analysis of the instrument were performed. The new, validated instrument, called CEC-61 (Conocimientos en Cancer Cérvicouterino-61 items/Knowledge in Cervical Cancer-61 items), contains nine factors and 61 items. The new questionnaire explained 81% of the variance with a reliability of 0.96. The assessment of knowledge with a valid and reliable instrument is the first step in creating interventions for a population and to encourage appropriate preventive behavior. CEC-61 is highly reliable and has a clear factorial structure to evaluate knowledge in nine domains related to cervical cancer disease, cervical cancer risk, papilloma virus infection, the Papanicolaou test, and the papilloma virus vaccine.

An accurate and efficient reliability-based design optimization using the second order reliability method and improved stability transformation method

NASA Astrophysics Data System (ADS)

Meng, Zeng; Yang, Dixiong; Zhou, Huanlin; Yu, Bo

2018-05-01

The first order reliability method has been extensively adopted for reliability-based design optimization (RBDO), but it shows inaccuracy in calculating the failure probability with highly nonlinear performance functions. Thus, the second order reliability method is required to evaluate the reliability accurately. However, its application for RBDO is quite challenge owing to the expensive computational cost incurred by the repeated reliability evaluation and Hessian calculation of probabilistic constraints. In this article, a new improved stability transformation method is proposed to search the most probable point efficiently, and the Hessian matrix is calculated by the symmetric rank-one update. The computational capability of the proposed method is illustrated and compared to the existing RBDO approaches through three mathematical and two engineering examples. The comparison results indicate that the proposed method is very efficient and accurate, providing an alternative tool for RBDO of engineering structures.

Development and Validation of the User Version of the Mobile Application Rating Scale (uMARS).

PubMed

Stoyanov, Stoyan R; Hides, Leanne; Kavanagh, David J; Wilson, Hollie

2016-06-10

The Mobile Application Rating Scale (MARS) provides a reliable method to assess the quality of mobile health (mHealth) apps. However, training and expertise in mHealth and the relevant health field is required to administer it. This study describes the development and reliability testing of an end-user version of the MARS (uMARS). The MARS was simplified and piloted with 13 young people to create the uMARS. The internal consistency and test-retest reliability of the uMARS was then examined in a second sample of 164 young people participating in a randomized controlled trial of a mHealth app. App ratings were collected using the uMARS at 1-, 3,- and 6-month follow up. The uMARS had excellent internal consistency (alpha = .90), with high individual alphas for all subscales. The total score and subscales had good test-retest reliability over both 1-2 months and 3 months. The uMARS is a simple tool that can be reliably used by end-users to assess the quality of mHealth apps.

Measuring first-line nurse manager work: instrument: development and testing.

PubMed

Cadmus, Edna; Wisniewska, Edyta K

2013-12-01

The objective of this study was to develop and test a 1st-line nurse manager (FLNM) work instrument to measure categories of work and frequency of activities. First-line nurse managers have been demonstrated to be key contributors in meeting organizational outcomes and patient and nurse satisfaction. Identifying the work of FLNMs is essential to help in the development of prioritization and sequence. The need for an instrument that can measure and categorize the work of FLNMs is indicated. The author-developed instrument was administered as a pilot study to 173 FLNMs in New Jersey. Descriptive statistics were analyzed, and validity and reliability were measured. Content validity was established through 2 focus groups using 10 FLNMs and conducting a survey of 5 chief nursing officers. Reliability was assessed by 13 of 16 FLNM participants using the test/retest method and quantified using percent agreement within a 10-day period. Those items with 70% agreement or more were identified as reliable and retained on the instrument. The content validity of the instrument is strong; further refinement and testing of the tool are indicated to improve the reliability and generalizability across multiple populations of leaders and settings.

Face Liveness Detection Using Defocus

PubMed Central

Kim, Sooyeon; Ban, Yuseok; Lee, Sangyoun

2015-01-01

In order to develop security systems for identity authentication, face recognition (FR) technology has been applied. One of the main problems of applying FR technology is that the systems are especially vulnerable to attacks with spoofing faces (e.g., 2D pictures). To defend from these attacks and to enhance the reliability of FR systems, many anti-spoofing approaches have been recently developed. In this paper, we propose a method for face liveness detection using the effect of defocus. From two images sequentially taken at different focuses, three features, focus, power histogram and gradient location and orientation histogram (GLOH), are extracted. Afterwards, we detect forged faces through the feature-level fusion approach. For reliable performance verification, we develop two databases with a handheld digital camera and a webcam. The proposed method achieves a 3.29% half total error rate (HTER) at a given depth of field (DoF) and can be extended to camera-equipped devices, like smartphones. PMID:25594594

The quadrant method measuring four points is as a reliable and accurate as the quadrant method in the evaluation after anatomical double-bundle ACL reconstruction.

PubMed

Mochizuki, Yuta; Kaneko, Takao; Kawahara, Keisuke; Toyoda, Shinya; Kono, Norihiko; Hada, Masaru; Ikegami, Hiroyasu; Musha, Yoshiro

2017-11-20

The quadrant method was described by Bernard et al. and it has been widely used for postoperative evaluation of anterior cruciate ligament (ACL) reconstruction. The purpose of this research is to further develop the quadrant method measuring four points, which we named four-point quadrant method, and to compare with the quadrant method. Three-dimensional computed tomography (3D-CT) analyses were performed in 25 patients who underwent double-bundle ACL reconstruction using the outside-in technique. The four points in this study's quadrant method were defined as point1-highest, point2-deepest, point3-lowest, and point4-shallowest, in femoral tunnel position. Value of depth and height in each point was measured. Antero-medial (AM) tunnel is (depth1, height2) and postero-lateral (PL) tunnel is (depth3, height4) in this four-point quadrant method. The 3D-CT images were evaluated independently by 2 orthopaedic surgeons. A second measurement was performed by both observers after a 4-week interval. Intra- and inter-observer reliability was calculated by means of intra-class correlation coefficient (ICC). Also, the accuracy of the method was evaluated against the quadrant method. Intra-observer reliability was almost perfect for both AM and PL tunnel (ICC > 0.81). Inter-observer reliability of AM tunnel was substantial (ICC > 0.61) and that of PL tunnel was almost perfect (ICC > 0.81). The AM tunnel position was 0.13% deep, 0.58% high and PL tunnel position was 0.01% shallow, 0.13% low compared to quadrant method. The four-point quadrant method was found to have high intra- and inter-observer reliability and accuracy. This method can evaluate the tunnel position regardless of the shape and morphology of the bone tunnel aperture for use of comparison and can provide measurement that can be compared with various reconstruction methods. The four-point quadrant method of this study is considered to have clinical relevance in that it is a detailed and accurate tool for evaluating femoral tunnel position after ACL reconstruction. Case series, Level IV.

The accuracy of ultrasound for measurement of mobile- bearing motion.

PubMed

Aigner, Christian; Radl, Roman; Pechmann, Michael; Rehak, Peter; Stacher, Rudolf; Windhager, Reinhard

2004-04-01

After anterior cruciate ligament-sacrificing total knee replacement, mobile bearings sometimes have paradoxic movement but the implications of such movement on function, wear, and implant survival are not known. To study this potential problem accurate, reliable, and widely available inexpensive tools for in vivo mobile-bearing motion analyses are needed. We developed a method using an 8-MHz ultrasound to analyze mobile-bearing motion and ascertained accuracy, precision, and reliability compared with plain and standard digital radiographs. The anterior rim of the mobile bearing was the target for all methods. The radiographs were taken in a horizontal plane at neutral rotation and incremental external and internal rotations. Five investigators examined four positions of the mobile bearing with all three methods. The accuracy and precision were: ultrasound, 0.7 mm and 0.2 mm; digital radiograph, 0.4 mm and 0.2 mm; and plain radiographs, 0.7 mm and 0.3 mm. The interrater and intrarater reliability ranged between 0.3 to 0.4 mm and 0.1 to 0.2 mm, respectively. The difference between the methods was not significant for neutral rotation but ultrasound was significantly more accurate than any one degree of rotation or higher. Ultrasound of 8 MHz provides an accuracy and reliability that is suitable for evaluation of in vivo meniscal bearing motion. Whether this method or others are sufficiently accurate to detect motion leading to abnormal wear is not known.

Building professional capacity in ITS : guidelines on developing the future professional

DOT National Transportation Integrated Search

1999-07-01

Time domain reflectometry (TDR) has become one of the most reliable methods for measuring in-situ soil moisture content. TDR sensors developed by the Federal Highway Administration (FHWA) are being used in the Long-Term Pavement Performance (LTPP) Se...

The Use of the Direct Optimized Probabilistic Calculation Method in Design of Bolt Reinforcement for Underground and Mining Workings

PubMed Central

Krejsa, Martin; Janas, Petr; Yilmaz, Işık; Marschalko, Marian; Bouchal, Tomas

2013-01-01

The load-carrying system of each construction should fulfill several conditions which represent reliable criteria in the assessment procedure. It is the theory of structural reliability which determines probability of keeping required properties of constructions. Using this theory, it is possible to apply probabilistic computations based on the probability theory and mathematic statistics. Development of those methods has become more and more popular; it is used, in particular, in designs of load-carrying structures with the required level or reliability when at least some input variables in the design are random. The objective of this paper is to indicate the current scope which might be covered by the new method—Direct Optimized Probabilistic Calculation (DOProC) in assessments of reliability of load-carrying structures. DOProC uses a purely numerical approach without any simulation techniques. This provides more accurate solutions to probabilistic tasks, and, in some cases, such approach results in considerably faster completion of computations. DOProC can be used to solve efficiently a number of probabilistic computations. A very good sphere of application for DOProC is the assessment of the bolt reinforcement in the underground and mining workings. For the purposes above, a special software application—“Anchor”—has been developed. PMID:23935412

A comparative study of first-derivative spectrophotometry and column high-performance liquid chromatography applied to the determination of repaglinide in tablets and for dissolution testing.

PubMed

AlKhalidi, Bashar A; Shtaiwi, Majed; AlKhatib, Hatim S; Mohammad, Mohammad; Bustanji, Yasser

2008-01-01

A fast and reliable method for the determination of repaglinide is highly desirable to support formulation screening and quality control. A first-derivative UV spectroscopic method was developed for the determination of repaglinide in tablet dosage form and for dissolution testing. First-derivative UV absorbance was measured at 253 nm. The developed method was validated for linearity, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) in comparison to the U.S. Pharmacopeia (USP) column high-performance liquid chromatographic (HPLC) method. The first-derivative UV spectrophotometric method showed excellent linearity [correlation coefficient (r) = 0.9999] in the concentration range of 1-35 microg/mL and precision (relative standard deviation < 1.5%). The LOD and LOQ were 0.23 and 0.72 microg/mL, respectively, and good recoveries were achieved (98-101.8%). Statistical comparison of results of the first-derivative UV spectrophotometric and the USP HPLC methods using the t-test showed that there was no significant difference between the 2 methods. Additionally, the method was successfully used for the dissolution test of repaglinide and was found to be reliable, simple, fast, and inexpensive.

High reliability and implications for nursing leaders.

PubMed

Riley, William

2009-03-01

To review high reliability theory and discuss its implications for the nursing leader. A high reliability organization (HRO) is considered that which has measurable near perfect performance for quality and safety. The author has reviewed the literature, discussed research findings that contribute to improving reliability in health care organizations, and makes five recommendations for how nursing leaders can create high reliability organizations. Health care is not a safe industry and unintended patient harm occurs at epidemic levels. Health care can learn from high reliability theory and practice developed in other high-risk industries. Viewed by HRO standards, unintended patient injury in health care is excessively high and quality is distressingly low. HRO theory and practice can be successfully applied in health care using advanced interdisciplinary teamwork training and deliberate process design techniques. Nursing has a primary leadership function for ensuring patient safety and achieving high quality in health care organizations. Learning HRO theory and methods for achieving high reliability is a foremost opportunity for nursing leaders.

Long-term Mechanical Circulatory Support System reliability recommendation by the National Clinical Trial Initiative subcommittee.

PubMed

Lee, James

2009-01-01

The Long-Term Mechanical Circulatory Support (MCS) System Reliability Recommendation was published in the American Society for Artificial Internal Organs (ASAIO) Journal and the Annals of Thoracic Surgery in 1998. At that time, it was stated that the document would be periodically reviewed to assess its timeliness and appropriateness within 5 years. Given the wealth of clinical experience in MCS systems, a new recommendation has been drafted by consensus of a group of representatives from the medical community, academia, industry, and government. The new recommendation describes a reliability test methodology and provides detailed reliability recommendations. In addition, the new recommendation provides additional information and clinical data in appendices that are intended to assist the reliability test engineer in the development of a reliability test that is expected to give improved predictions of clinical reliability compared with past test methods. The appendices are available for download at the ASAIO journal web site at www.asaiojournal.com.

Mapping the ecological networks of microbial communities.

PubMed

Xiao, Yandong; Angulo, Marco Tulio; Friedman, Jonathan; Waldor, Matthew K; Weiss, Scott T; Liu, Yang-Yu

2017-12-11

Mapping the ecological networks of microbial communities is a necessary step toward understanding their assembly rules and predicting their temporal behavior. However, existing methods require assuming a particular population dynamics model, which is not known a priori. Moreover, those methods require fitting longitudinal abundance data, which are often not informative enough for reliable inference. To overcome these limitations, here we develop a new method based on steady-state abundance data. Our method can infer the network topology and inter-taxa interaction types without assuming any particular population dynamics model. Additionally, when the population dynamics is assumed to follow the classic Generalized Lotka-Volterra model, our method can infer the inter-taxa interaction strengths and intrinsic growth rates. We systematically validate our method using simulated data, and then apply it to four experimental data sets. Our method represents a key step towards reliable modeling of complex, real-world microbial communities, such as the human gut microbiota.

Air-bridged Ohmic contact on vertically aligned si nanowire arrays: application to molecule sensors.

PubMed

Han, Hee; Kim, Jungkil; Shin, Ho Sun; Song, Jae Yong; Lee, Woo

2012-05-02

A simple, cost-effective, and highly reliable method for constructing an air-bridged electrical contact on large arrays of vertically aligned nanowires was developed. The present method may open up new opportunities for developing advanced nanowire-based devices for energy harvest and storage, power generation, and sensing applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Measuring the severity of topical 5-fluorouracil toxicity.

PubMed

Korgavkar, Kaveri; Firoz, Elnaz F; Xiong, Michael; Lew, Robert; Marcolivio, Kimberly; Burnside, Nancy; Dyer, Robert; Weinstock, Martin A

2014-01-01

Topical 5% 5-fluorouracil (5-FU) is known to cause toxicity, such as erythema, pain, and crusting/erosions. We sought to develop a scale to measure this toxicity and test the scale for reliability. A scale was developed involving four parameters: erythema severity, percentage of face involved in erythema, crusting/erosions severity, and percentage of face involved in crusting/erosions. Thirteen raters graded 99 sets of photographs from the Veterans Affairs Keratinocyte Carcinoma Chemoprevention (VAKCC) Trial using these parameters. Intraclass correlation overall for 13 raters was 0.82 (95% CI 0.77-0.86). There was no statistically significant trend in reliability by level of training in dermatology. This scale is a reliable method of evaluating the severity of toxicity from topical 5-fluorouracil and can be used by dermatologists and nondermatologists alike.

Reliability analysis of a wastewater treatment plant using fault tree analysis and Monte Carlo simulation.

PubMed

Taheriyoun, Masoud; Moradinejad, Saber

2015-01-01

The reliability of a wastewater treatment plant is a critical issue when the effluent is reused or discharged to water resources. Main factors affecting the performance of the wastewater treatment plant are the variation of the influent, inherent variability in the treatment processes, deficiencies in design, mechanical equipment, and operational failures. Thus, meeting the established reuse/discharge criteria requires assessment of plant reliability. Among many techniques developed in system reliability analysis, fault tree analysis (FTA) is one of the popular and efficient methods. FTA is a top down, deductive failure analysis in which an undesired state of a system is analyzed. In this study, the problem of reliability was studied on Tehran West Town wastewater treatment plant. This plant is a conventional activated sludge process, and the effluent is reused in landscape irrigation. The fault tree diagram was established with the violation of allowable effluent BOD as the top event in the diagram, and the deficiencies of the system were identified based on the developed model. Some basic events are operator's mistake, physical damage, and design problems. The analytical method is minimal cut sets (based on numerical probability) and Monte Carlo simulation. Basic event probabilities were calculated according to available data and experts' opinions. The results showed that human factors, especially human error had a great effect on top event occurrence. The mechanical, climate, and sewer system factors were in subsequent tier. Literature shows applying FTA has been seldom used in the past wastewater treatment plant (WWTP) risk analysis studies. Thus, the developed FTA model in this study considerably improves the insight into causal failure analysis of a WWTP. It provides an efficient tool for WWTP operators and decision makers to achieve the standard limits in wastewater reuse and discharge to the environment.

Spatially Regularized Machine Learning for Task and Resting-state fMRI

PubMed Central

Song, Xiaomu; Panych, Lawrence P.; Chen, Nan-kuei

2015-01-01

Background Reliable mapping of brain function across sessions and/or subjects in task- and resting-state has been a critical challenge for quantitative fMRI studies although it has been intensively addressed in the past decades. New Method A spatially regularized support vector machine (SVM) technique was developed for the reliable brain mapping in task- and resting-state. Unlike most existing SVM-based brain mapping techniques, which implement supervised classifications of specific brain functional states or disorders, the proposed method performs a semi-supervised classification for the general brain function mapping where spatial correlation of fMRI is integrated into the SVM learning. The method can adapt to intra- and inter-subject variations induced by fMRI nonstationarity, and identify a true boundary between active and inactive voxels, or between functionally connected and unconnected voxels in a feature space. Results The method was evaluated using synthetic and experimental data at the individual and group level. Multiple features were evaluated in terms of their contributions to the spatially regularized SVM learning. Reliable mapping results in both task- and resting-state were obtained from individual subjects and at the group level. Comparison with Existing Methods A comparison study was performed with independent component analysis, general linear model, and correlation analysis methods. Experimental results indicate that the proposed method can provide a better or comparable mapping performance at the individual and group level. Conclusions The proposed method can provide accurate and reliable mapping of brain function in task- and resting-state, and is applicable to a variety of quantitative fMRI studies. PMID:26470627

Reliability based design including future tests and multiagent approaches

NASA Astrophysics Data System (ADS)

Villanueva, Diane

The initial stages of reliability-based design optimization involve the formulation of objective functions and constraints, and building a model to estimate the reliability of the design with quantified uncertainties. However, even experienced hands often overlook important objective functions and constraints that affect the design. In addition, uncertainty reduction measures, such as tests and redesign, are often not considered in reliability calculations during the initial stages. This research considers two areas that concern the design of engineering systems: 1) the trade-off of the effect of a test and post-test redesign on reliability and cost and 2) the search for multiple candidate designs as insurance against unforeseen faults in some designs. In this research, a methodology was developed to estimate the effect of a single future test and post-test redesign on reliability and cost. The methodology uses assumed distributions of computational and experimental errors with re-design rules to simulate alternative future test and redesign outcomes to form a probabilistic estimate of the reliability and cost for a given design. Further, it was explored how modeling a future test and redesign provides a company an opportunity to balance development costs versus performance by simultaneously designing the design and the post-test redesign rules during the initial design stage. The second area of this research considers the use of dynamic local surrogates, or surrogate-based agents, to locate multiple candidate designs. Surrogate-based global optimization algorithms often require search in multiple candidate regions of design space, expending most of the computation needed to define multiple alternate designs. Thus, focusing on solely locating the best design may be wasteful. We extended adaptive sampling surrogate techniques to locate multiple optima by building local surrogates in sub-regions of the design space to identify optima. The efficiency of this method was studied, and the method was compared to other surrogate-based optimization methods that aim to locate the global optimum using two two-dimensional test functions, a six-dimensional test function, and a five-dimensional engineering example.

Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers.

PubMed

Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

2014-02-14

Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10,000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm(-2). The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices.

Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers

NASA Astrophysics Data System (ADS)

Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

2014-02-01

Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10 000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm-2. The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices.

Evaluation of the fast orthogonal search method for forecasting chloride levels in the Deltona groundwater supply (Florida, USA)

NASA Astrophysics Data System (ADS)

El-Jaat, Majda; Hulley, Michael; Tétreault, Michel

2018-02-01

Despite the broad impact and importance of saltwater intrusion in coastal aquifers, little research has been directed towards forecasting saltwater intrusion in areas where the source of saltwater is uncertain. Saline contamination in inland groundwater supplies is a concern for numerous communities in the southern US including the city of Deltona, Florida. Furthermore, conventional numerical tools for forecasting saltwater contamination are heavily dependent on reliable characterization of the physical characteristics of underlying aquifers, information that is often absent or challenging to obtain. To overcome these limitations, a reliable alternative data-driven model for forecasting salinity in a groundwater supply was developed for Deltona using the fast orthogonal search (FOS) method. FOS was applied on monthly water-demand data and corresponding chloride concentrations at water supply wells. Groundwater salinity measurements from Deltona water supply wells were applied to evaluate the forecasting capability and accuracy of the FOS model. Accurate and reliable groundwater salinity forecasting is necessary to support effective and sustainable coastal-water resource planning and management. The available (27) water supply wells for Deltona were randomly split into three test groups for the purposes of FOS model development and performance assessment. Based on four performance indices (RMSE, RSR, NSEC, and R), the FOS model proved to be a reliable and robust forecaster of groundwater salinity. FOS is relatively inexpensive to apply, is not based on rigorous physical characterization of the water supply aquifer, and yields reliable estimates of groundwater salinity in active water supply wells.

The reliability and validity of a three-camera foot image system for obtaining foot anthropometrics.

PubMed

O'Meara, Damien; Vanwanseele, Benedicte; Hunt, Adrienne; Smith, Richard

2010-08-01

The purpose was to develop a foot image capture and measurement system with web cameras (the 3-FIS) to provide reliable and valid foot anthropometric measures with efficiency comparable to that of the conventional method of using a handheld anthropometer. Eleven foot measures were obtained from 10 subjects using both methods. Reliability of each method was determined over 3 consecutive days using the intraclass correlation coefficient and root mean square error (RMSE). Reliability was excellent for both the 3-FIS and the handheld anthropometer for the same 10 variables, and good for the fifth metatarsophalangeal joint height. The RMSE values over 3 days ranged from 0.9 to 2.2 mm for the handheld anthropometer, and from 0.8 to 3.6 mm for the 3-FIS. The RMSE values between the 3-FIS and the handheld anthropometer were between 2.3 and 7.4 mm. The 3-FIS required less time to collect and obtain the final variables than the handheld anthropometer. The 3-FIS provided accurate and reproducible results for each of the foot variables and in less time than the conventional approach of a handheld anthropometer.

Phased-mission system analysis using Boolean algebraic methods

NASA Technical Reports Server (NTRS)

Somani, Arun K.; Trivedi, Kishor S.

1993-01-01

Most reliability analysis techniques and tools assume that a system is used for a mission consisting of a single phase. However, multiple phases are natural in many missions. The failure rates of components, system configuration, and success criteria may vary from phase to phase. In addition, the duration of a phase may be deterministic or random. Recently, several researchers have addressed the problem of reliability analysis of such systems using a variety of methods. A new technique for phased-mission system reliability analysis based on Boolean algebraic methods is described. Our technique is computationally efficient and is applicable to a large class of systems for which the failure criterion in each phase can be expressed as a fault tree (or an equivalent representation). Our technique avoids state space explosion that commonly plague Markov chain-based analysis. A phase algebra to account for the effects of variable configurations and success criteria from phase to phase was developed. Our technique yields exact (as opposed to approximate) results. The use of our technique was demonstrated by means of an example and present numerical results to show the effects of mission phases on the system reliability.

An accelerated subspace iteration for eigenvector derivatives

NASA Technical Reports Server (NTRS)

Ting, Tienko

1991-01-01

An accelerated subspace iteration method for calculating eigenvector derivatives has been developed. Factors affecting the effectiveness and the reliability of the subspace iteration are identified, and effective strategies concerning these factors are presented. The method has been implemented, and the results of a demonstration problem are presented.

Lidar Based Emissions Measurement at the Whole Facility Scale: Method and Error Analysis

USDA-ARS?s Scientific Manuscript database

Particulate emissions from agricultural sources vary from dust created by operations and animal movement to the fine secondary particulates generated from ammonia and other emitted gases. The development of reliable facility emission data using point sampling methods designed to characterize regiona...

Reliability Issues and Solutions in Flexible Electronics Under Mechanical Fatigue

NASA Astrophysics Data System (ADS)

Yi, Seol-Min; Choi, In-Suk; Kim, Byoung-Joon; Joo, Young-Chang

2018-07-01

Flexible devices are of significant interest due to their potential expansion of the application of smart devices into various fields, such as energy harvesting, biological applications and consumer electronics. Due to the mechanically dynamic operations of flexible electronics, their mechanical reliability must be thoroughly investigated to understand their failure mechanisms and lifetimes. Reliability issue caused by bending fatigue, one of the typical operational limitations of flexible electronics, has been studied using various test methodologies; however, electromechanical evaluations which are essential to assess the reliability of electronic devices for flexible applications had not been investigated because the testing method was not established. By employing the in situ bending fatigue test, we has studied the failure mechanism for various conditions and parameters, such as bending strain, fatigue area, film thickness, and lateral dimensions. Moreover, various methods for improving the bending reliability have been developed based on the failure mechanism. Nanostructures such as holes, pores, wires and composites of nanoparticles and nanotubes have been suggested for better reliability. Flexible devices were also investigated to find the potential failures initiated by complex structures under bending fatigue strain. In this review, the recent advances in test methodology, mechanism studies, and practical applications are introduced. Additionally, perspectives including the future advance to stretchable electronics are discussed based on the current achievements in research.

The Validity and Reliability Test of the Indonesian Version of Gastroesophageal Reflux Disease Quality of Life (GERD-QOL) Questionnaire.

PubMed

Siahaan, Laura A; Syam, Ari F; Simadibrata, Marcellus; Setiati, Siti

2017-01-01

to obtain a valid and reliable GERD-QOL questionnaire for Indonesian application. at the initial stage, the GERD-QOL questionnaire was first translated into Indonesian language and the translated questionnaire was subsequently translated back into the original language (back-to-back translation). The results were evaluated by the researcher team and therefore, an Indonesian version of GERD-QOL questionnaire was developed. Ninety-one patients who had been clinically diagnosed with GERD based on the Montreal criteria were interviewed using the Indonesian version of GERD-QOL questionnaire and the SF 36 questionnaire. The validity was evaluated using a method of construct validity and external validity, and reliability can be tested by the method of internal consistency and test retest. the Indonesian version of GERD-QOL questionnaire had a good internal consistency reliability with a Cronbach Alpha of 0.687-0.842 and a good test retest reliability with an intra-class correlation coefficient of 0.756-0.936; p<0.05). The questionnaire had also been demonstrated to have a good validity with a proven high correlation to each question of SF-36 (p<0.05). the Indonesian version of GERD-QOL questionnaire has been proven valid and reliable to evaluate the quality of life of GERD patients.

Reliability Issues and Solutions in Flexible Electronics Under Mechanical Fatigue

NASA Astrophysics Data System (ADS)

Yi, Seol-Min; Choi, In-Suk; Kim, Byoung-Joon; Joo, Young-Chang

2018-03-01

Flexible devices are of significant interest due to their potential expansion of the application of smart devices into various fields, such as energy harvesting, biological applications and consumer electronics. Due to the mechanically dynamic operations of flexible electronics, their mechanical reliability must be thoroughly investigated to understand their failure mechanisms and lifetimes. Reliability issue caused by bending fatigue, one of the typical operational limitations of flexible electronics, has been studied using various test methodologies; however, electromechanical evaluations which are essential to assess the reliability of electronic devices for flexible applications had not been investigated because the testing method was not established. By employing the in situ bending fatigue test, we has studied the failure mechanism for various conditions and parameters, such as bending strain, fatigue area, film thickness, and lateral dimensions. Moreover, various methods for improving the bending reliability have been developed based on the failure mechanism. Nanostructures such as holes, pores, wires and composites of nanoparticles and nanotubes have been suggested for better reliability. Flexible devices were also investigated to find the potential failures initiated by complex structures under bending fatigue strain. In this review, the recent advances in test methodology, mechanism studies, and practical applications are introduced. Additionally, perspectives including the future advance to stretchable electronics are discussed based on the current achievements in research.

A New Tool for Nutrition App Quality Evaluation (AQEL): Development, Validation, and Reliability Testing

PubMed Central

Huang, Wenhao; Chapman-Novakofski, Karen M

2017-01-01

Background The extensive availability and increasing use of mobile apps for nutrition-based health interventions makes evaluation of the quality of these apps crucial for integration of apps into nutritional counseling. Objective The goal of this research was the development, validation, and reliability testing of the app quality evaluation (AQEL) tool, an instrument for evaluating apps’ educational quality and technical functionality. Methods Items for evaluating app quality were adapted from website evaluations, with additional items added to evaluate the specific characteristics of apps, resulting in 79 initial items. Expert panels of nutrition and technology professionals and app users reviewed items for face and content validation. After recommended revisions, nutrition experts completed a second AQEL review to ensure clarity. On the basis of 150 sets of responses using the revised AQEL, principal component analysis was completed, reducing AQEL into 5 factors that underwent reliability testing, including internal consistency, split-half reliability, test-retest reliability, and interrater reliability (IRR). Two additional modifiable constructs for evaluating apps based on the age and needs of the target audience as selected by the evaluator were also tested for construct reliability. IRR testing using intraclass correlations (ICC) with all 7 constructs was conducted, with 15 dietitians evaluating one app. Results Development and validation resulted in the 51-item AQEL. These were reduced to 25 items in 5 factors after principal component analysis, plus 9 modifiable items in two constructs that were not included in principal component analysis. Internal consistency and split-half reliability of the following constructs derived from principal components analysis was good (Cronbach alpha >.80, Spearman-Brown coefficient >.80): behavior change potential, support of knowledge acquisition, app function, and skill development. App purpose split half-reliability was .65. Test-retest reliability showed no significant change over time (P>.05) for all but skill development (P=.001). Construct reliability was good for items assessing age appropriateness of apps for children, teens, and a general audience. In addition, construct reliability was acceptable for assessing app appropriateness for various target audiences (Cronbach alpha >.70). For the 5 main factors, ICC (1,k) was >.80, with a P value of <.05. When 15 nutrition professionals evaluated one app, ICC (2,15) was .98, with a P value of <.001 for all 7 constructs when the modifiable items were specified for adults seeking weight loss support. Conclusions Our preliminary effort shows that AQEL is a valid, reliable instrument for evaluating nutrition apps’ qualities for clinical interventions by nutrition clinicians, educators, and researchers. Further efforts in validating AQEL in various contexts are needed. PMID:29079554

Development and preliminary validation of a questionnaire to measure satisfaction with home care in Greece: an exploratory factor analysis of polychoric correlations

PubMed Central

2010-01-01

Background The primary aim of this study was to develop and psychometrically test a Greek-language instrument for measuring satisfaction with home care. The first empirical evidence about the level of satisfaction with these services in Greece is also provided. Methods The questionnaire resulted from literature search, on-site observation and cognitive interviews. It was applied in 2006 to a sample of 201 enrollees of five home care programs in the city of Thessaloniki and contains 31 items that measure satisfaction with individual service attributes and are expressed on a 5-point Likert scale. The latter has been usually considered in practice as an interval scale, although it is in principle ordinal. We thus treated the variable as an ordinal one, but also employed the traditional approach in order to compare the findings. Our analysis was therefore based on ordinal measures such as the polychoric correlation, Kendall's Tau b coefficient and ordinal Cronbach's alpha. Exploratory factor analysis was followed by an assessment of internal consistency reliability, test-retest reliability, construct validity and sensitivity. Results Analyses with ordinal and interval scale measures produced in essence very similar results and identified four multi-item scales. Three of these were found to be reliable and valid: socioeconomic change, staff skills and attitudes and service appropriateness. A fourth dimension -service planning- had lower internal consistency reliability and yet very satisfactory test-retest reliability, construct validity and floor and ceiling effects. The global satisfaction scale created was also quite reliable. Overall, participants were satisfied -yet not very satisfied- with home care services. More room for improvement seems to exist for the socio-economic and planning aspects of care and less for staff skills and attitudes and appropriateness of provided services. Conclusions The methods developed seem to be a promising tool for the measurement of home care satisfaction in Greece. PMID:20602759

NDE detectability of fatigue type cracks in high strength alloys

NASA Technical Reports Server (NTRS)

Christner, B. K.; Rummel, W. D.

1983-01-01

Specimens suitable for investigating the reliability of production nondestructive evaluation (NDE) to detect tightly closed fatigue cracks in high strength alloys representative of those materials used in spacecraft engine/booster construction were produced. Inconel 718 was selected as representative of nickel base alloys and Haynes 188 was selected as representative of cobalt base alloys used in this application. Cleaning procedures were developed to insure the reusability of the test specimens and a flaw detection reliability assessment of the fluorescent penetrant inspection method was performed using the test specimens produced to characterize their use for future reliability assessments and to provide additional NDE flaw detection reliability data for high strength alloys. The statistical analysis of the fluorescent penetrant inspection data was performed to determine the detection reliabilities for each inspection at a 90% probability/95% confidence level.

Assessment of Lower Limb Muscle Strength and Power Using Hand-Held and Fixed Dynamometry: A Reliability and Validity Study

PubMed Central

Perraton, Luke G.; Bower, Kelly J.; Adair, Brooke; Pua, Yong-Hao; Williams, Gavin P.; McGaw, Rebekah

2015-01-01

Introduction Hand-held dynamometry (HHD) has never previously been used to examine isometric muscle power. Rate of force development (RFD) is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power. Methods 30 healthy young adults (age: 23±5yrs, male: 15) were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2) and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC), Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change. Results Comparison of RFD methods revealed that a peak 200ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70) for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70) for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31–0.79). Conclusions Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability and validity of these variables in clinical populations. PMID:26509265

Toward reliable and repeatable automated STEM-EDS metrology with high throughput

NASA Astrophysics Data System (ADS)

Zhong, Zhenxin; Donald, Jason; Dutrow, Gavin; Roller, Justin; Ugurlu, Ozan; Verheijen, Martin; Bidiuk, Oleksii

2018-03-01

New materials and designs in complex 3D architectures in logic and memory devices have raised complexity in S/TEM metrology. In this paper, we report about a newly developed, automated, scanning transmission electron microscopy (STEM) based, energy dispersive X-ray spectroscopy (STEM-EDS) metrology method that addresses these challenges. Different methodologies toward repeatable and efficient, automated STEM-EDS metrology with high throughput are presented: we introduce the best known auto-EDS acquisition and quantification methods for robust and reliable metrology and present how electron exposure dose impacts the EDS metrology reproducibility, either due to poor signalto-noise ratio (SNR) at low dose or due to sample modifications at high dose conditions. Finally, we discuss the limitations of the STEM-EDS metrology technique and propose strategies to optimize the process both in terms of throughput and metrology reliability.

Using Ensemble Decisions and Active Selection to Improve Low-Cost Labeling for Multi-View Data

NASA Technical Reports Server (NTRS)

Rebbapragada, Umaa; Wagstaff, Kiri L.

2011-01-01

This paper seeks to improve low-cost labeling in terms of training set reliability (the fraction of correctly labeled training items) and test set performance for multi-view learning methods. Co-training is a popular multiview learning method that combines high-confidence example selection with low-cost (self) labeling. However, co-training with certain base learning algorithms significantly reduces training set reliability, causing an associated drop in prediction accuracy. We propose the use of ensemble labeling to improve reliability in such cases. We also discuss and show promising results on combining low-cost ensemble labeling with active (low-confidence) example selection. We unify these example selection and labeling strategies under collaborative learning, a family of techniques for multi-view learning that we are developing for distributed, sensor-network environments.

Formation of integrated structural units using the systematic and integrated method when implementing high-rise construction projects

NASA Astrophysics Data System (ADS)

Abramov, Ivan

2018-03-01

Development of design documentation for a future construction project gives rise to a number of issues with the main one being selection of manpower for structural units of the project's overall implementation system. Well planned and competently staffed integrated structural construction units will help achieve a high level of reliability and labor productivity and avoid negative (extraordinary) situations during the construction period eventually ensuring improved project performance. Research priorities include the development of theoretical recommendations for enhancing reliability of a structural unit staffed as an integrated construction crew. The author focuses on identification of destabilizing factors affecting formation of an integrated construction crew; assessment of these destabilizing factors; based on the developed mathematical model, highlighting the impact of these factors on the integration criterion with subsequent identification of an efficiency and reliability criterion for the structural unit in general. The purpose of this article is to develop theoretical recommendations and scientific and methodological provisions of an organizational and technological nature in order to identify a reliability criterion for a structural unit based on manpower integration and productivity criteria. With this purpose in mind, complex scientific tasks have been defined requiring special research, development of corresponding provisions and recommendations based on the system analysis findings presented herein.

Advancing methods for reliably assessing motivational interviewing fidelity using the Motivational Interviewing Skills Code

PubMed Central

Lord, Sarah Peregrine; Can, Doğan; Yi, Michael; Marin, Rebeca; Dunn, Christopher W.; Imel, Zac E.; Georgiou, Panayiotis; Narayanan, Shrikanth; Steyvers, Mark; Atkins, David C.

2014-01-01

The current paper presents novel methods for collecting MISC data and accurately assessing reliability of behavior codes at the level of the utterance. The MISC 2.1 was used to rate MI interviews from five randomized trials targeting alcohol and drug use. Sessions were coded at the utterance-level. Utterance-based coding reliability was estimated using three methods and compared to traditional reliability estimates of session tallies. Session-level reliability was generally higher compared to reliability using utterance-based codes, suggesting that typical methods for MISC reliability may be biased. These novel methods in MI fidelity data collection and reliability assessment provided rich data for therapist feedback and further analyses. Beyond implications for fidelity coding, utterance-level coding schemes may elucidate important elements in the counselor-client interaction that could inform theories of change and the practice of MI. PMID:25242192

Advancing methods for reliably assessing motivational interviewing fidelity using the motivational interviewing skills code.

PubMed

Lord, Sarah Peregrine; Can, Doğan; Yi, Michael; Marin, Rebeca; Dunn, Christopher W; Imel, Zac E; Georgiou, Panayiotis; Narayanan, Shrikanth; Steyvers, Mark; Atkins, David C

2015-02-01

The current paper presents novel methods for collecting MISC data and accurately assessing reliability of behavior codes at the level of the utterance. The MISC 2.1 was used to rate MI interviews from five randomized trials targeting alcohol and drug use. Sessions were coded at the utterance-level. Utterance-based coding reliability was estimated using three methods and compared to traditional reliability estimates of session tallies. Session-level reliability was generally higher compared to reliability using utterance-based codes, suggesting that typical methods for MISC reliability may be biased. These novel methods in MI fidelity data collection and reliability assessment provided rich data for therapist feedback and further analyses. Beyond implications for fidelity coding, utterance-level coding schemes may elucidate important elements in the counselor-client interaction that could inform theories of change and the practice of MI. Copyright © 2015 Elsevier Inc. All rights reserved.

A marker placement laser device for improving repeatability in 3D-foot motion analysis.

PubMed

Kalkum, Eva; van Drongelen, Stefan; Mussler, Johannes; Wolf, Sebastian I; Kuni, Benita

2016-02-01

In 3D gait analysis, the repeated positioning of markers is associated with a high error rate, particularly when using a complex foot model with many markers. Therefore, a marker placement laser device was developed that ensures a reliable repositioning of markers. We report the development and reliability of this device for the foot at different tape conditions. In 38 subjects, markers were placed at the foot according to the Heidelberg foot measurement method. Subjects were tested barefoot and barefoot with three different tape conditions. For all conditions, a static standing trial was captured. We analyzed differences in distances between markers and the intra-class correlation coefficients (ICC). Small differences between the conditions (0.03-3.28 mm) and excellent ICCs (0.91-0.97 mm) were found for all parameters. The laser marker placement device appeared to be a reliable method to place markers on a tape at previously palpated positions and ensures an exact position. The device could find a wide application in different clinical research fields. Copyright © 2015 Elsevier B.V. All rights reserved.

Environmental and human monitoring of Americium-241 utilizing extraction chromatography and {alpha}-Spectrometry

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

Goldstein, S.J.; Hensley, C.A.; Armenta, C.E.

1997-03-01

Recent developments in extraction chromatography have simplified the separation of americium from complex matrices in preparation for {alpha}-spectroscopy relative to traditional methods. Here we present results of procedures developed/adapted for water, air, and bioassay samples with less than 1 g of inorganic residue. Prior analytical methods required the use of a complex, multistage procedure for separation of americium from these matrices. The newer, simplified procedure requires only a single 2 mL extraction chromatographic separation for isolation of Am and lanthanides from other components of the sample. This method has been implemented on an extensive variety of `real` environmental and bioassaymore » samples from the Los Alamos area, and consistently reliable and accurate results with appropriate detection limits have been obtained. The new method increases analytical throughput by a factor of {approx}2 and decreases environmental hazards from acid and mixed-waste generation relative to the prior technique. Analytical accuracy, reproducibility, and reliability are also significantly improved over the more complex and laborious method used previously. 24 refs., 2 figs., 2 tabs.« less

Independent component analysis-based algorithm for automatic identification of Raman spectra applied to artistic pigments and pigment mixtures.

PubMed

González-Vidal, Juan José; Pérez-Pueyo, Rosanna; Soneira, María José; Ruiz-Moreno, Sergio

2015-03-01

A new method has been developed to automatically identify Raman spectra, whether they correspond to single- or multicomponent spectra. The method requires no user input or judgment. There are thus no parameters to be tweaked. Furthermore, it provides a reliability factor on the resulting identification, with the aim of becoming a useful support tool for the analyst in the decision-making process. The method relies on the multivariate techniques of principal component analysis (PCA) and independent component analysis (ICA), and on some metrics. It has been developed for the application of automated spectral analysis, where the analyzed spectrum is provided by a spectrometer that has no previous knowledge of the analyzed sample, meaning that the number of components in the sample is unknown. We describe the details of this method and demonstrate its efficiency by identifying both simulated spectra and real spectra. The method has been applied to artistic pigment identification. The reliable and consistent results that were obtained make the methodology a helpful tool suitable for the identification of pigments in artwork or in paint in general.

A Targeted LC-MS/MS Method for the Simultaneous Detection and Quantitation of Egg, Milk, and Peanut Allergens in Sugar Cookies.

PubMed

Boo, Chelsea C; Parker, Christine H; Jackson, Lauren S

2018-01-01

Food allergy is a growing public health concern, with many individuals reporting allergies to multiple food sources. Compliance with food labeling regulations and prevention of inadvertent cross-contact in manufacturing requires the use of reliable methods for the detection and quantitation of allergens in processed foods. In this work, a novel liquid chromatography-tandem mass spectrometry multiple-reaction monitoring method for multiallergen detection and quantitation of egg, milk, and peanut was developed and evaluated in an allergen-incurred baked sugar cookie matrix. A systematic evaluation of method parameters, including sample extraction, concentration, and digestion, were optimized for candidate allergen peptide markers. The optimized method enabled the reliable detection and quantitation of egg, milk, and peanut allergens in sugar cookies, with allergen concentrations as low as 5 ppm allergen-incurred ingredient.

ASR testing : a new approach to aggregate classification and mix design verification : technical report.

DOT National Transportation Integrated Search

2014-04-01

The main objective of this study was to develop a fast, reliable test method to determine the aggregate alkali-silica reactivity : (ASR) with respect to the overall alkalinity of the concrete. A volumetric change measuring device (VCMD) developed at ...

Quantifying Error in Survey Measures of School and Classroom Environments

ERIC Educational Resources Information Center

Schweig, Jonathan David

2014-01-01

Developing indicators that reflect important aspects of school and classroom environments has become central in a nationwide effort to develop comprehensive programs that measure teacher quality and effectiveness. Formulating teacher evaluation policy necessitates accurate and reliable methods for measuring these environmental variables. This…

Self-Tuning Method for Increased Obstacle Detection Reliability Based on Internet of Things LiDAR Sensor Models

PubMed Central

2018-01-01

On-chip LiDAR sensors for vehicle collision avoidance are a rapidly expanding area of research and development. The assessment of reliable obstacle detection using data collected by LiDAR sensors has become a key issue that the scientific community is actively exploring. The design of a self-tuning methodology and its implementation are presented in this paper, to maximize the reliability of LiDAR sensors network for obstacle detection in the ‘Internet of Things’ (IoT) mobility scenarios. The Webots Automobile 3D simulation tool for emulating sensor interaction in complex driving environments is selected in order to achieve that objective. Furthermore, a model-based framework is defined that employs a point-cloud clustering technique, and an error-based prediction model library that is composed of a multilayer perceptron neural network, and k-nearest neighbors and linear regression models. Finally, a reinforcement learning technique, specifically a Q-learning method, is implemented to determine the number of LiDAR sensors that are required to increase sensor reliability for obstacle localization tasks. In addition, a IoT driving assistance user scenario, connecting a five LiDAR sensor network is designed and implemented to validate the accuracy of the computational intelligence-based framework. The results demonstrated that the self-tuning method is an appropriate strategy to increase the reliability of the sensor network while minimizing detection thresholds. PMID:29748521

Reliable probabilities through statistical post-processing of ensemble predictions

NASA Astrophysics Data System (ADS)

Van Schaeybroeck, Bert; Vannitsem, Stéphane

2013-04-01

We develop post-processing or calibration approaches based on linear regression that make ensemble forecasts more reliable. We enforce climatological reliability in the sense that the total variability of the prediction is equal to the variability of the observations. Second, we impose ensemble reliability such that the spread around the ensemble mean of the observation coincides with the one of the ensemble members. In general the attractors of the model and reality are inhomogeneous. Therefore ensemble spread displays a variability not taken into account in standard post-processing methods. We overcome this by weighting the ensemble by a variable error. The approaches are tested in the context of the Lorenz 96 model (Lorenz 1996). The forecasts become more reliable at short lead times as reflected by a flatter rank histogram. Our best method turns out to be superior to well-established methods like EVMOS (Van Schaeybroeck and Vannitsem, 2011) and Nonhomogeneous Gaussian Regression (Gneiting et al., 2005). References [1] Gneiting, T., Raftery, A. E., Westveld, A., Goldman, T., 2005: Calibrated probabilistic forecasting using ensemble model output statistics and minimum CRPS estimation. Mon. Weather Rev. 133, 1098-1118. [2] Lorenz, E. N., 1996: Predictability - a problem partly solved. Proceedings, Seminar on Predictability ECMWF. 1, 1-18. [3] Van Schaeybroeck, B., and S. Vannitsem, 2011: Post-processing through linear regression, Nonlin. Processes Geophys., 18, 147.

Self-Tuning Method for Increased Obstacle Detection Reliability Based on Internet of Things LiDAR Sensor Models.

PubMed

Castaño, Fernando; Beruvides, Gerardo; Villalonga, Alberto; Haber, Rodolfo E

2018-05-10

On-chip LiDAR sensors for vehicle collision avoidance are a rapidly expanding area of research and development. The assessment of reliable obstacle detection using data collected by LiDAR sensors has become a key issue that the scientific community is actively exploring. The design of a self-tuning methodology and its implementation are presented in this paper, to maximize the reliability of LiDAR sensors network for obstacle detection in the 'Internet of Things' (IoT) mobility scenarios. The Webots Automobile 3D simulation tool for emulating sensor interaction in complex driving environments is selected in order to achieve that objective. Furthermore, a model-based framework is defined that employs a point-cloud clustering technique, and an error-based prediction model library that is composed of a multilayer perceptron neural network, and k-nearest neighbors and linear regression models. Finally, a reinforcement learning technique, specifically a Q-learning method, is implemented to determine the number of LiDAR sensors that are required to increase sensor reliability for obstacle localization tasks. In addition, a IoT driving assistance user scenario, connecting a five LiDAR sensor network is designed and implemented to validate the accuracy of the computational intelligence-based framework. The results demonstrated that the self-tuning method is an appropriate strategy to increase the reliability of the sensor network while minimizing detection thresholds.

The Development and Validation of the Age-Based Rejection Sensitivity Questionnaire

ERIC Educational Resources Information Center

Kang, Sonia K.; Chasteen, Alison L.

2009-01-01

Purpose: There is much evidence suggesting that older adults are often negatively affected by aging stereotypes; however, no method to identify individual differences in vulnerability to these effects has yet been developed. The purpose of this study was to develop a reliable and valid questionnaire to measure individual differences in the…

Development and Validation of the Evidence-Based Practice Process Assessment Scale: Preliminary Findings

ERIC Educational Resources Information Center

Rubin, Allen; Parrish, Danielle E.

2010-01-01

Objective: This report describes the development and preliminary findings regarding the reliability, validity, and sensitivity of a scale that has been developed to assess practitioners' perceived familiarity with, attitudes about, and implementation of the phases of the evidence-based practice (EBP) process. Method: After a panel of national…

Developments in Cylindrical Shell Stability Analysis

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Starnes, James H., Jr.

1998-01-01

Today high-performance computing systems and new analytical and numerical techniques enable engineers to explore the use of advanced materials for shell design. This paper reviews some of the historical developments of shell buckling analysis and design. The paper concludes by identifying key research directions for reliable and robust methods development in shell stability analysis and design.

Design, application and testing of the Work Observation Method by Activity Timing (WOMBAT) to measure clinicians' patterns of work and communication.

PubMed

Westbrook, Johanna I; Ampt, Amanda

2009-04-01

Evidence regarding how health information technologies influence clinicians' patterns of work and support efficient practices is limited. Traditional paper-based data collection methods are unable to capture clinical work complexity and communication patterns. The use of electronic data collection tools for such studies is emerging yet is rarely assessed for reliability or validity. Our aim was to design, apply and test an observational method which incorporated the use of an electronic data collection tool for work measurement studies which would allow efficient, accurate and reliable data collection, and capture greater degrees of work complexity than current approaches. We developed an observational method and software for personal digital assistants (PDAs) which captures multiple dimensions of clinicians' work tasks, namely what task, with whom, and with what; tasks conducted in parallel (multi-tasking); interruptions and task duration. During field-testing over 7 months across four hospital wards, fifty-two nurses were observed for 250 h. Inter-rater reliability was tested and validity was measured by (i) assessing whether observational data reflected known differences in clinical role work tasks and (ii) by comparing observational data with participants' estimates of their task time distribution. Observers took 15-20 h of training to master the method and data collection process. Only 1% of tasks observed did not match the classification developed and were classified as 'other'. Inter-rater reliability scores of observers were maintained at over 85%. The results discriminated between the work patterns of enrolled and registered nurses consistent with differences in their roles. Survey data (n=27) revealed consistent ratings of tasks by nurses, and their rankings of most to least time-consuming tasks were significantly correlated with those derived from the observational data. Over 40% of nurses' time was spent in direct care or professional communication, with 11.8% of time spent multi-tasking. Nurses were interrupted approximately every 49 min. One quarter of interruptions occurred while nurses were preparing or administering medications. This method efficiently produces reliable and valid data. The multi-dimensional nature of the data collected provides greater insights into patterns of clinicians' work and communication than has previously been possible using other methods.

The Arthroscopic Surgical Skill Evaluation Tool (ASSET)

PubMed Central

Koehler, Ryan J.; Amsdell, Simon; Arendt, Elizabeth A; Bisson, Leslie J; Braman, Jonathan P; Butler, Aaron; Cosgarea, Andrew J; Harner, Christopher D; Garrett, William E; Olson, Tyson; Warme, Winston J.; Nicandri, Gregg T.

2014-01-01

Background Surgeries employing arthroscopic techniques are among the most commonly performed in orthopaedic clinical practice however, valid and reliable methods of assessing the arthroscopic skill of orthopaedic surgeons are lacking. Hypothesis The Arthroscopic Surgery Skill Evaluation Tool (ASSET) will demonstrate content validity, concurrent criterion-oriented validity, and reliability, when used to assess the technical ability of surgeons performing diagnostic knee arthroscopy on cadaveric specimens. Study Design Cross-sectional study; Level of evidence, 3 Methods Content validity was determined by a group of seven experts using a Delphi process. Intra-articular performance of a right and left diagnostic knee arthroscopy was recorded for twenty-eight residents and two sports medicine fellowship trained attending surgeons. Subject performance was assessed by two blinded raters using the ASSET. Concurrent criterion-oriented validity, inter-rater reliability, and test-retest reliability were evaluated. Results Content validity: The content development group identified 8 arthroscopic skill domains to evaluate using the ASSET. Concurrent criterion-oriented validity: Significant differences in total ASSET score (p<0.05) between novice, intermediate, and advanced experience groups were identified. Inter-rater reliability: The ASSET scores assigned by each rater were strongly correlated (r=0.91, p <0.01) and the intra-class correlation coefficient between raters for the total ASSET score was 0.90. Test-retest reliability: there was a significant correlation between ASSET scores for both procedures attempted by each individual (r = 0.79, p<0.01). Conclusion The ASSET appears to be a useful, valid, and reliable method for assessing surgeon performance of diagnostic knee arthroscopy in cadaveric specimens. Studies are ongoing to determine its generalizability to other procedures as well as to the live OR and other simulated environments. PMID:23548808

RELIABILITY AND VALIDITY OF A BIOMECHANICALLY BASED ANALYSIS METHOD FOR THE TENNIS SERVE

PubMed Central

Kibler, W. Ben; Lamborn, Leah; Smith, Belinda J.; English, Tony; Jacobs, Cale; Uhl, Tim L.

2017-01-01

Background An observational tennis serve analysis (OTSA) tool was developed using previously established body positions from three-dimensional kinematic motion analysis studies. These positions, defined as nodes, have been associated with efficient force production and minimal joint loading. However, the tool has yet to be examined scientifically. Purpose The primary purpose of this investigation was to determine the inter-observer reliability for each node between two health care professionals (HCPs) that developed the OTSA, and secondarily to investigate the validity of the OTSA. Methods Two separate studies were performed to meet these objectives. An inter-observer reliability study preceded the validity study by examining 28 videos of players serving. Two HCPs graded each video and scored the presence or absence of obtaining each node. Discriminant validity was determined in 33 tennis players using video taped records of three first serves. Serve mechanics were graded using the OSTA and categorized players into those with good ( ≥ 5) and poor ( ≤ 4) mechanics. Participants performed a series of field tests to evaluate trunk flexibility, lower extremity and trunk power, and dynamic balance. Results The group with good mechanics demonstrated greater backward trunk flexibility (p=0.02), greater rotational power (p=0.02), and higher single leg countermovement jump (p=0.05). Reliability of the OTSA ranged from K = 0.36-1.0, with the majority of all the nodes displaying substantial reliability (K>0.61). Conclusion This study provides HCPs with a valid and reliable field tool used to assess serve mechanics. Physical characteristics of trunk mobility and power appear to discriminate serve mechanics between players. Future intervention studies are needed to determine if improvement in physical function contribute to improved serve mechanics. Level of Evidence 3 PMID:28593098

Reliability and Validity of the Research Methods Skills Assessment

ERIC Educational Resources Information Center

Smith, Tamarah; Smith, Samantha

2018-01-01

The Research Methods Skills Assessment (RMSA) was created to measure psychology majors' statistics knowledge and skills. The American Psychological Association's Guidelines for the Undergraduate Major in Psychology (APA, 2007, 2013) served as a framework for development. Results from a Rasch analysis with data from n = 330 undergraduates showed…

Summertime Temperatures in Buildings Without Air-Conditioning.

ERIC Educational Resources Information Center

Loudon, A. G.

Many modern buildings become uncomfortably warm during sunny spells in the summer, and until recently there was no simple, reliable method of assessing at the design stage whether a building would become overheated. This paper describes a method of calculating summertime temperatures which was developed at the Building Research Station, and gives…

75 FR 2523 - Office of Innovation and Improvement; Overview Information; Arts in Education Model Development...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

... that is based on rigorous scientifically based research methods to assess the effectiveness of a...) Relies on measurements or observational methods that provide reliable and valid data across evaluators... of innovative, cohesive models that are based on research and have demonstrated that they effectively...

METHOD FOR MEASURING BASE/NEUTRAL AND CARBAMATE PESTICIDES IN PERSONAL DIETARY SAMPLES

EPA Science Inventory

Dietary uptake may be a significant pathway of exposure to contaminants. As such,dietary exposure assessments should be considered an important part of the total exposure assessment process. The objective of this work was to develop reliable methods that are applicable to a wide ...

METHOD FOR MEASURING BASE/NEUTRAL AND CARBAMATE PESTICIDES IN PERSONAL DIETARY SAMPLES

EPA Science Inventory

Dietary uptake may be a significant pathway of exposure to contaminants. As such, dietary exposure assessments should be considered an important part of the total exposure assessment process. The objective of this work was to develop reliable methods that are applicable to a wide...

Considerations regarding the validation of chromatographic mass spectrometric methods for the quantification of endogenous substances in forensics.

PubMed

Hess, Cornelius; Sydow, Konrad; Kueting, Theresa; Kraemer, Michael; Maas, Alexandra

2018-02-01

The requirement for correct evaluation of forensic toxicological results in daily routine work and scientific studies is reliable analytical data based on validated methods. Validation of a method gives the analyst tools to estimate the efficacy and reliability of the analytical method. Without validation, data might be contested in court and lead to unjustified legal consequences for a defendant. Therefore, new analytical methods to be used in forensic toxicology require careful method development and validation of the final method. Until now, there are no publications on the validation of chromatographic mass spectrometric methods for the detection of endogenous substances although endogenous analytes can be important in Forensic Toxicology (alcohol consumption marker, congener alcohols, gamma hydroxy butyric acid, human insulin and C-peptide, creatinine, postmortal clinical parameters). For these analytes, conventional validation instructions cannot be followed completely. In this paper, important practical considerations in analytical method validation for endogenous substances will be discussed which may be used as guidance for scientists wishing to develop and validate analytical methods for analytes produced naturally in the human body. Especially the validation parameters calibration model, analytical limits, accuracy (bias and precision) and matrix effects and recovery have to be approached differently. Highest attention should be paid to selectivity experiments. Copyright © 2017 Elsevier B.V. All rights reserved.

NDE reliability and probability of detection (POD) evolution and paradigm shift

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

Singh, Surendra

2014-02-18

The subject of NDE Reliability and POD has gone through multiple phases since its humble beginning in the late 1960s. This was followed by several programs including the important one nicknamed “Have Cracks – Will Travel” or in short “Have Cracks” by Lockheed Georgia Company for US Air Force during 1974–1978. This and other studies ultimately led to a series of developments in the field of reliability and POD starting from the introduction of fracture mechanics and Damaged Tolerant Design (DTD) to statistical framework by Bernes and Hovey in 1981 for POD estimation to MIL-STD HDBK 1823 (1999) and 1823Amore » (2009). During the last decade, various groups and researchers have further studied the reliability and POD using Model Assisted POD (MAPOD), Simulation Assisted POD (SAPOD), and applying Bayesian Statistics. All and each of these developments had one objective, i.e., improving accuracy of life prediction in components that to a large extent depends on the reliability and capability of NDE methods. Therefore, it is essential to have a reliable detection and sizing of large flaws in components. Currently, POD is used for studying reliability and capability of NDE methods, though POD data offers no absolute truth regarding NDE reliability, i.e., system capability, effects of flaw morphology, and quantifying the human factors. Furthermore, reliability and POD have been reported alike in meaning but POD is not NDE reliability. POD is a subset of the reliability that consists of six phases: 1) samples selection using DOE, 2) NDE equipment setup and calibration, 3) System Measurement Evaluation (SME) including Gage Repeatability and Reproducibility (Gage R and R) and Analysis Of Variance (ANOVA), 4) NDE system capability and electronic and physical saturation, 5) acquiring and fitting data to a model, and data analysis, and 6) POD estimation. This paper provides an overview of all major POD milestones for the last several decades and discuss rationale for using Integrated Computational Materials Engineering (ICME), MAPOD, SAPOD, and Bayesian statistics for studying controllable and non-controllable variables including human factors for estimating POD. Another objective is to list gaps between “hoped for” versus validated or fielded failed hardware.« less

Development of X-ray computed tomography inspection facility for the H-II solid rocket boosters

NASA Astrophysics Data System (ADS)

Sasaki, M.; Fujita, T.; Fukushima, Y.; Shimizu, M.; Itoh, S.; Satoh, A.; Miyamoto, H.

The National Space Development Agency of Japan (NASDA) initiated the development of an X-ray computed tomography (CT) equipment for the H-II solid rocket boosters (SRBs) in 1987 for the purpose of minimizing inspection time and achieving high cost-effectiveness. The CT facility has been completed in Jan. 1991 in Tanegashima Space Center for the inspection of the SRBs transported from the manufacturer's factory to the launch site. It was first applied to the qualification model SRB from Feb. to Apr. in 1991. Through the CT inspection of the SRB, it has been confirmed that inspection time decreased significantly compared with the X-ray radiography method and that even an unskilled inspector could find various defects. As a result, the establishment of a new reliable inspection method for the SRB has been verified. In this paper, the following are discussed: (1) the defect detectability of the CT equipment using a dummy SRB with various artificial defects, (2) the performance comparison between the CT method and the X-ray radiography method, (3) the reliability of the CT equipment, and (4) the radiation shield design of the nondestructive test building.

A review of surface energy balance models for estimating actual evapotranspiration with remote sensing at high spatiotemporal resolution over large extents

Treesearch

Ryan R. McShane; Katelyn P. Driscoll; Roy Sando

2017-01-01

Many approaches have been developed for measuring or estimating actual evapotranspiration (ETa), and research over many years has led to the development of remote sensing methods that are reliably reproducible and effective in estimating ETa. Several remote sensing methods can be used to estimate ETa at the high spatial resolution of agricultural fields and the large...

Using Google Earth to Assess Shade for Sun Protection in Urban Recreation Spaces: Methods and Results.

PubMed

Gage, R; Wilson, N; Signal, L; Barr, M; Mackay, C; Reeder, A; Thomson, G

2018-05-16

Shade in public spaces can lower the risk of and sun burning and skin cancer. However, existing methods of auditing shade require travel between sites, and sunny weather conditions. This study aimed to evaluate the feasibility of free computer software-Google Earth-for assessing shade in urban open spaces. A shade projection method was developed that uses Google Earth street view and aerial images to estimate shade at solar noon on the summer solstice, irrespective of the date of image capture. Three researchers used the method to separately estimate shade cover over pre-defined activity areas in a sample of 45 New Zealand urban open spaces, including 24 playgrounds, 12 beaches and 9 outdoor pools. Outcome measures included method accuracy (assessed by comparison with a subsample of field observations of 10 of the settings) and inter-rater reliability. Of the 164 activity areas identified in the 45 settings, most (83%) had no shade cover. The method identified most activity areas in playgrounds (85%) and beaches (93%) and was accurate for assessing shade over these areas (predictive values of 100%). Only 8% of activity areas at outdoor pools were identified, due to a lack of street view images. Reliability for shade cover estimates was excellent (intraclass correlation coefficient of 0.97, 95% CI 0.97-0.98). Google Earth appears to be a reasonably accurate and reliable and shade audit tool for playgrounds and beaches. The findings are relevant for programmes focused on supporting the development of healthy urban open spaces.

Development and Evaluation of a Measure of Library Automation.

ERIC Educational Resources Information Center

Pungitore, Verna L.

1986-01-01

Construct validity and reliability estimates indicate that study designed to measure utilization of automation in public and academic libraries was successful in tentatively identifying and measuring three subdimensions of level of automation: quality of hardware, method of software development, and number of automation specialists. Questionnaire…

Methods for quantification of soil-transmitted helminths in environmental media: current techniques and recent advances

PubMed Central

Collender, Philip A.; Kirby, Amy E.; Addiss, David G.; Freeman, Matthew C.; Remais, Justin V.

2015-01-01

Limiting the environmental transmission of soil-transmitted helminths (STH), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost effective methods to detect and quantify STH in the environment. We review the state of the art of STH quantification in soil, biosolids, water, produce, and vegetation with respect to four major methodological issues: environmental sampling; recovery of STH from environmental matrices; quantification of recovered STH; and viability assessment of STH ova. We conclude that methods for sampling and recovering STH require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment. PMID:26440788

Software Development Processes Applied to Computational Icing Simulation

NASA Technical Reports Server (NTRS)

Levinson, Laurie H.; Potapezuk, Mark G.; Mellor, Pamela A.

1999-01-01

The development of computational icing simulation methods is making the transition form the research to common place use in design and certification efforts. As such, standards of code management, design validation, and documentation must be adjusted to accommodate the increased expectations of the user community with respect to accuracy, reliability, capability, and usability. This paper discusses these concepts with regard to current and future icing simulation code development efforts as implemented by the Icing Branch of the NASA Lewis Research Center in collaboration with the NASA Lewis Engineering Design and Analysis Division. With the application of the techniques outlined in this paper, the LEWICE ice accretion code has become a more stable and reliable software product.

Space Shuttle Software Development and Certification

NASA Technical Reports Server (NTRS)

Orr, James K.; Henderson, Johnnie A

2000-01-01

Man-rated software, "software which is in control of systems and environments upon which human life is critically dependent," must be highly reliable. The Space Shuttle Primary Avionics Software System is an excellent example of such a software system. Lessons learn from more than 20 years of effort have identified basic elements that must be present to achieve this high degree of reliability. The elements include rigorous application of appropriate software development processes, use of trusted tools to support those processes, quantitative process management, and defect elimination and prevention. This presentation highlights methods used within the Space Shuttle project and raises questions that must be addressed to provide similar success in a cost effective manner on future long-term projects where key application development tools are COTS rather than internally developed custom application development tools

Skeletal maturation in individuals with Down's syndrome: Comparison between PGS curve, cervical vertebrae and bones of the hand and wrist

PubMed Central

Carinhena, Glauber; Siqueira, Danilo Furquim; Sannomiya, Eduardo Kazuo

2014-01-01

Introduction This study was conducted with the aim of adapting the methods developed by Martins and Sakima to assess skeletal maturation by cervical vertebrae in the pubertal growth spurt (PGS) curve. It also aimed to test the reliability and agreement between those methods and the method of hand and wrist radiograph when compared two by two and all together. Methods The sample comprised 72 radiographs, with 36 lateral radiographs of the head and 36 hand-wrist radiographs of 36 subjects with Down's syndrome (DS), 13 female and 23 male, aged between 8 years and 6 months and 18 years and 7 months, with an average age of 13 years and 10 months. Results and Conclusions Results revealed that adapting the methods developed by Martins and Sakima to assess skeletal maturation by cervical vertebrae in the curve of PGS is practical and useful in determining the stage of growth and development of individuals. The stages of maturation evaluated by cervical vertebrae and ossification centers observed in radiographs of the hand and wrist were considered reliable, with excellent level of agreement between the methods by Hassel and Farman as well as Baccetti, Franchi and McNamara Jr and Martins and Sakima. Additionally, results revealed an agreement that ranged between reasonable to good for the three methods used to assess the skeletal maturation, showing statistical significance. PMID:25279522

Hawaii electric system reliability.

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

Silva Monroy, Cesar Augusto; Loose, Verne William

2012-09-01

This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers' views of reliability %E2%80%9Cworth%E2%80%9D and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and formore » application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers' views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.« less

Hawaii Electric System Reliability

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

Loose, Verne William; Silva Monroy, Cesar Augusto

2012-08-01

This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers’ views of reliability “worth” and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and formore » application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers’ views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.« less

Assessment of the Validity of the Research Diagnostic Criteria for Temporomandibular Disorders: Overview and Methodology

PubMed Central

Schiffman, Eric L.; Truelove, Edmond L.; Ohrbach, Richard; Anderson, Gary C.; John, Mike T.; List, Thomas; Look, John O.

2011-01-01

AIMS The purpose of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Validation Project was to assess the diagnostic validity of this examination protocol. An overview is presented, including Axis I and II methodology and descriptive statistics for the study participant sample. This paper details the development of reliable methods to establish the reference standards for assessing criterion validity of the Axis I RDC/TMD diagnoses. Validity testing for the Axis II biobehavioral instruments was based on previously validated reference standards. METHODS The Axis I reference standards were based on the consensus of 2 criterion examiners independently performing a comprehensive history, clinical examination, and evaluation of imaging. Intersite reliability was assessed annually for criterion examiners and radiologists. Criterion exam reliability was also assessed within study sites. RESULTS Study participant demographics were comparable to those of participants in previous studies using the RDC/TMD. Diagnostic agreement of the criterion examiners with each other and with the consensus-based reference standards was excellent with all kappas ≥ 0.81, except for osteoarthrosis (moderate agreement, k = 0.53). Intrasite criterion exam agreement with reference standards was excellent (k ≥ 0.95). Intersite reliability of the radiologists for detecting computed tomography-disclosed osteoarthrosis and magnetic resonance imaging-disclosed disc displacement was good to excellent (k = 0.71 and 0.84, respectively). CONCLUSION The Validation Project study population was appropriate for assessing the reliability and validity of the RDC/TMD Axis I and II. The reference standards used to assess the validity of Axis I TMD were based on reliable and clinically credible methods. PMID:20213028

An accurate and reliable method of thermal data analysis in thermal imaging of the anterior knee for use in cryotherapy research.

PubMed

Selfe, James; Hardaker, Natalie; Thewlis, Dominic; Karki, Anna

2006-12-01

To develop an anatomic marker system (AMS) as an accurate, reliable method of thermal imaging data analysis, for use in cryotherapy research. Investigation of the accuracy of new thermal imaging technique. Hospital orthopedic outpatient department in England. Consecutive sample of 9 patients referred to anterior knee pain clinic. Not applicable. Thermally inert markers were placed at specific anatomic locations, defining an area over the anterior knee of patients with anterior knee pain. A baseline thermal image was taken. Patients underwent a 3-minute thermal washout of the affected knee. Thermal images were collected at a rate of 1 image per minute for a 20-minute re-warming period. A Matlab (version 7.0) program was written to digitize the marker positions and subsequently calculate the mean of the area over the anterior knee. Virtual markers were then defined as 15% distal from the proximal marker, 30% proximal from the distal markers, 15% lateral from the medial marker, and 15% medial from the lateral marker. The virtual markers formed an ellipse, which defined an area representative of the patella shape. Within the ellipse, the mean value of the full pixels determined the mean temperature of this region. Ten raters were recruited to use the program and interrater reliability was investigated. The intraclass correlation coefficient produced coefficients within acceptable bounds, ranging from .82 to .97, indicating adequate interrater reliability. The AMS provides an accurate, reliable method for thermal imaging data analysis and is a reliable tool with which to advance cryotherapy research.

Best Practices for Reliable and Robust Spacecraft Structures

NASA Technical Reports Server (NTRS)

Raju, Ivatury S.; Murthy, P. L. N.; Patel, Naresh R.; Bonacuse, Peter J.; Elliott, Kenny B.; Gordon, S. A.; Gyekenyesi, J. P.; Daso, E. O.; Aggarwal, P.; Tillman, R. F.

2007-01-01

A study was undertaken to capture the best practices for the development of reliable and robust spacecraft structures for NASA s next generation cargo and crewed launch vehicles. In this study, the NASA heritage programs such as Mercury, Gemini, Apollo, and the Space Shuttle program were examined. A series of lessons learned during the NASA and DoD heritage programs are captured. The processes that "make the right structural system" are examined along with the processes to "make the structural system right". The impact of technology advancements in materials and analysis and testing methods on reliability and robustness of spacecraft structures is studied. The best practices and lessons learned are extracted from these studies. Since the first human space flight, the best practices for reliable and robust spacecraft structures appear to be well established, understood, and articulated by each generation of designers and engineers. However, these best practices apparently have not always been followed. When the best practices are ignored or short cuts are taken, risks accumulate, and reliability suffers. Thus program managers need to be vigilant of circumstances and situations that tend to violate best practices. Adherence to the best practices may help develop spacecraft systems with high reliability and robustness against certain anomalies and unforeseen events.

Measurement of Surface Interfacial Tension as a Function of Temperature Using Pendant Drop Images

NASA Astrophysics Data System (ADS)

Yakhshi-Tafti, Ehsan; Kumar, Ranganathan; Cho, Hyoung J.

2011-10-01

Accurate and reliable measurements of surface tension at the interface of immiscible phases are crucial to understanding various physico-chemical reactions taking place between those. Based on the pendant drop method, an optical (graphical)-numerical procedure was developed to determine surface tension and its dependency on the surrounding temperature. For modeling and experimental verification, chemically inert and thermally stable perfluorocarbon (PFC) oil and water was used. Starting with geometrical force balance, governing equations were derived to provide non-dimensional parameters which were later used to extract values for surface tension. Comparative study verified the accuracy and reliability of the proposed method.

Constructing the "Best" Reliability Data for the Job

NASA Technical Reports Server (NTRS)

DeMott, D. L.; Kleinhammer, R. K.

2014-01-01

Modern business and technical decisions are based on the results of analyses. When considering assessments using "reliability data", the concern is how long a system will continue to operate as designed. Generally, the results are only as good as the data used. Ideally, a large set of pass/fail tests or observations to estimate the probability of failure of the item under test would produce the best data. However, this is a costly endeavor if used for every analysis and design. Developing specific data is costly and time consuming. Instead, analysts rely on available data to assess reliability. Finding data relevant to the specific use and environment for any project is difficult, if not impossible. Instead, we attempt to develop the "best" or composite analog data to support our assessments. One method used incorporates processes for reviewing existing data sources and identifying the available information based on similar equipment, then using that generic data to derive an analog composite. Dissimilarities in equipment descriptions, environment of intended use, quality and even failure modes impact the "best" data incorporated in an analog composite. Once developed, this composite analog data provides a "better" representation of the reliability of the equipment or component can be used to support early risk or reliability trade studies, or analytical models to establish the predicted reliability data points. Data that is more representative of reality and more project specific would provide more accurate analysis, and hopefully a better final decision.

Constructing the Best Reliability Data for the Job

NASA Technical Reports Server (NTRS)

Kleinhammer, R. K.; Kahn, J. C.

2014-01-01

Modern business and technical decisions are based on the results of analyses. When considering assessments using "reliability data", the concern is how long a system will continue to operate as designed. Generally, the results are only as good as the data used. Ideally, a large set of pass/fail tests or observations to estimate the probability of failure of the item under test would produce the best data. However, this is a costly endeavor if used for every analysis and design. Developing specific data is costly and time consuming. Instead, analysts rely on available data to assess reliability. Finding data relevant to the specific use and environment for any project is difficult, if not impossible. Instead, we attempt to develop the "best" or composite analog data to support our assessments. One method used incorporates processes for reviewing existing data sources and identifying the available information based on similar equipment, then using that generic data to derive an analog composite. Dissimilarities in equipment descriptions, environment of intended use, quality and even failure modes impact the "best" data incorporated in an analog composite. Once developed, this composite analog data provides a "better" representation of the reliability of the equipment or component can be used to support early risk or reliability trade studies, or analytical models to establish the predicted reliability data points. Data that is more representative of reality and more project specific would provide more accurate analysis, and hopefully a better final decision.

Fixed-Node Diffusion Quantum Monte Carlo Method on Dissociation Energies and Their Trends for R-X Bonds (R = Me, Et, i-Pr, t-Bu).

PubMed

Hou, Aiqiang; Zhou, Xiaojun; Wang, Ting; Wang, Fan

2018-05-15

Achieving both bond dissociation energies (BDEs) and their trends for the R-X bonds with R = Me, Et, i-Pr, and t-Bu reliably is nontrivial. Density functional theory (DFT) methods with traditional exchange-correlation functionals usually have large error on both the BDEs and their trends. The M06-2X functional gives rise to reliable BDEs, but the relative BDEs are determined not as accurately. More demanding approaches such as some double-hybrid functionals, for example, G4 and CCSD(T), are generally required to achieve the BDEs and their trends reliably. The fixed-node diffusion quantum Monte Carlo method (FN-DMC) is employed to calculated BDEs of these R-X bonds with X = H, CH 3 , OCH 3 , OH, and F in this work. The single Slater-Jastrow wave function is adopted as trial wave function, and pseudopotentials (PPs) developed for quantum Monte Carlo calculations are chosen. Error of these PPs is modest in wave function methods, while it is more pronounced in DFT calculations. Our results show that accuracy of BDEs with FN-DMC is similar to that of M06-2X and G4, and trends in BDEs are calculated more reliably than M06-2X. Both BDEs and trends in BDEs of these bonds are reproduced reasonably with FN-DMC. FN-DMC using PPs can thus be applied to BDEs and their trends of similar chemical bonds in larger molecules reliably and provide valuable information on properties of these molecules.

ASSESSING AND COMBINING RELIABILITY OF PROTEIN INTERACTION SOURCES

PubMed Central

LEACH, SONIA; GABOW, AARON; HUNTER, LAWRENCE; GOLDBERG, DEBRA S.

2008-01-01

Integrating diverse sources of interaction information to create protein networks requires strategies sensitive to differences in accuracy and coverage of each source. Previous integration approaches calculate reliabilities of protein interaction information sources based on congruity to a designated ‘gold standard.’ In this paper, we provide a comparison of the two most popular existing approaches and propose a novel alternative for assessing reliabilities which does not require a gold standard. We identify a new method for combining the resultant reliabilities and compare it against an existing method. Further, we propose an extrinsic approach to evaluation of reliability estimates, considering their influence on the downstream tasks of inferring protein function and learning regulatory networks from expression data. Results using this evaluation method show 1) our method for reliability estimation is an attractive alternative to those requiring a gold standard and 2) the new method for combining reliabilities is less sensitive to noise in reliability assignments than the similar existing technique. PMID:17990508

Source Data Applicability Impacts on Epistemic Uncertainty for Launch Vehicle Fault Tree Models

NASA Technical Reports Server (NTRS)

Al Hassan, Mohammad; Novack, Steven D.; Ring, Robert W.

2016-01-01

Launch vehicle systems are designed and developed using both heritage and new hardware. Design modifications to the heritage hardware to fit new functional system requirements can impact the applicability of heritage reliability data. Risk estimates for newly designed systems must be developed from generic data sources such as commercially available reliability databases using reliability prediction methodologies, such as those addressed in MIL-HDBK-217F. Failure estimates must be converted from the generic environment to the specific operating environment of the system where it is used. In addition, some qualification of applicability for the data source to the current system should be made. Characterizing data applicability under these circumstances is crucial to developing model estimations that support confident decisions on design changes and trade studies. This paper will demonstrate a data-source applicability classification method for assigning uncertainty to a target vehicle based on the source and operating environment of the originating data. The source applicability is determined using heuristic guidelines while translation of operating environments is accomplished by applying statistical methods to MIL-HDK-217F tables. The paper will provide a case study example by translating Ground Benign (GB) and Ground Mobile (GM) to the Airborne Uninhabited Fighter (AUF) environment for three electronic components often found in space launch vehicle control systems. The classification method will be followed by uncertainty-importance routines to assess the need to for more applicable data to reduce uncertainty.

Molecular differentiation of Russian wild ginseng using mitochondrial nad7 intron 3 region.

PubMed

Li, Guisheng; Cui, Yan; Wang, Hongtao; Kwon, Woo-Saeng; Yang, Deok-Chun

2017-07-01

Cultivated ginseng is often introduced as a substitute and adulterant of Russian wild ginseng due to its lower cost or misidentification caused by similarity in appearance with wild ginseng. The aim of this study is to develop a simple and reliable method to differentiate Russian wild ginseng from cultivated ginseng. The mitochondrial NADH dehydrogenase subunit 7 ( nad 7) intron 3 regions of Russian wild ginseng and Chinese cultivated ginseng were analyzed. Based on the multiple sequence alignment result, a specific primer for Russian wild ginseng was designed by introducing additional mismatch and allele-specific polymerase chain reaction (PCR) was performed for identification of wild ginseng. Real-time allele-specific PCR with endpoint analysis was used for validation of the developed Russian wild ginseng single nucleotide polymorphism (SNP) marker. An SNP site specific to Russian wild ginseng was exploited by multiple alignments of mitochondrial nad 7 intron 3 regions of different ginseng samples. With the SNP-based specific primer, Russian wild ginseng was successfully discriminated from Chinese and Korean cultivated ginseng samples by allele-specific PCR. The reliability and specificity of the SNP marker was validated by checking 20 individuals of Russian wild ginseng samples with real-time allele-specific PCR assay. An effective DNA method for molecular discrimination of Russian wild ginseng from Chinese and Korean cultivated ginseng was developed. The established real-time allele-specific PCR was simple and reliable, and the present method should be a crucial complement of chemical analysis for authentication of Russian wild ginseng.

A reliable algorithm for optimal control synthesis

NASA Technical Reports Server (NTRS)

Vansteenwyk, Brett; Ly, Uy-Loi

1992-01-01

In recent years, powerful design tools for linear time-invariant multivariable control systems have been developed based on direct parameter optimization. In this report, an algorithm for reliable optimal control synthesis using parameter optimization is presented. Specifically, a robust numerical algorithm is developed for the evaluation of the H(sup 2)-like cost functional and its gradients with respect to the controller design parameters. The method is specifically designed to handle defective degenerate systems and is based on the well-known Pade series approximation of the matrix exponential. Numerical test problems in control synthesis for simple mechanical systems and for a flexible structure with densely packed modes illustrate positively the reliability of this method when compared to a method based on diagonalization. Several types of cost functions have been considered: a cost function for robust control consisting of a linear combination of quadratic objectives for deterministic and random disturbances, and one representing an upper bound on the quadratic objective for worst case initial conditions. Finally, a framework for multivariable control synthesis has been developed combining the concept of closed-loop transfer recovery with numerical parameter optimization. The procedure enables designers to synthesize not only observer-based controllers but also controllers of arbitrary order and structure. Numerical design solutions rely heavily on the robust algorithm due to the high order of the synthesis model and the presence of near-overlapping modes. The design approach is successfully applied to the design of a high-bandwidth control system for a rotorcraft.

SMART empirical approaches for predicting field performance of PV modules from results of reliability tests

NASA Astrophysics Data System (ADS)

Hardikar, Kedar Y.; Liu, Bill J. J.; Bheemreddy, Venkata

2016-09-01

Gaining an understanding of degradation mechanisms and their characterization are critical in developing relevant accelerated tests to ensure PV module performance warranty over a typical lifetime of 25 years. As newer technologies are adapted for PV, including new PV cell technologies, new packaging materials, and newer product designs, the availability of field data over extended periods of time for product performance assessment cannot be expected within the typical timeframe for business decisions. In this work, to enable product design decisions and product performance assessment for PV modules utilizing newer technologies, Simulation and Mechanism based Accelerated Reliability Testing (SMART) methodology and empirical approaches to predict field performance from accelerated test results are presented. The method is demonstrated for field life assessment of flexible PV modules based on degradation mechanisms observed in two accelerated tests, namely, Damp Heat and Thermal Cycling. The method is based on design of accelerated testing scheme with the intent to develop relevant acceleration factor models. The acceleration factor model is validated by extensive reliability testing under different conditions going beyond the established certification standards. Once the acceleration factor model is validated for the test matrix a modeling scheme is developed to predict field performance from results of accelerated testing for particular failure modes of interest. Further refinement of the model can continue as more field data becomes available. While the demonstration of the method in this work is for thin film flexible PV modules, the framework and methodology can be adapted to other PV products.

Rapid Development and Validation of Improved Reversed-Phase High-performance Liquid Chromatography Method for the Quantification of Mangiferin, a Polyphenol Xanthone Glycoside in Mangifera indica

PubMed Central

Naveen, P.; Lingaraju, H. B.; Prasad, K. Shyam

2017-01-01

Mangiferin, a polyphenolic xanthone glycoside from Mangifera indica, is used as traditional medicine for the treatment of numerous diseases. The present study was aimed to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC) method for the quantification of mangiferin from the bark extract of M. indica. RP-HPLC analysis was performed by isocratic elution with a low-pressure gradient using 0.1% formic acid: acetonitrile (87:13) as a mobile phase with a flow rate of 1.5 ml/min. The separation was done at 26°C using a Kinetex XB-C18 column as stationary phase and the detection wavelength at 256 nm. The proposed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification, and robustness by the International Conference on Harmonisation guidelines. In linearity, the excellent correlation coefficient more than 0.999 indicated good fitting of the curve and also good linearity. The intra- and inter-day precision showed < 1% of relative standard deviation of peak area indicated high reliability and reproducibility of the method. The recovery values at three different levels (50%, 100%, and 150%) of spiked samples were found to be 100.47, 100.89, and 100.99, respectively, and low standard deviation value < 1% shows high accuracy of the method. In robustness, the results remain unaffected by small variation in the analytical parameters, which shows the robustness of the method. Liquid chromatography–mass spectrometry analysis confirmed the presence of mangiferin with M/Z value of 421. The assay developed by HPLC method is a simple, rapid, and reliable for the determination of mangiferin from M. indica. SUMMARY The present study was intended to develop and validate an RP-HPLC method for the quantification of mangiferin from the bark extract of M. indica. The developed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification and robustness by International Conference on Harmonization guidelines. This study proved that the developed assay by HPLC method is a simple, rapid and reliable for the quantification of the mangiferin from M. indica. Abbreviations Used: M. indica: Mangifera indica, RP-HPLC: Reversed-phase high-performance liquid chromatography, M/Z: Mass to charge ratio, ICH: International conference on harmonization, % RSD: Percentage of relative standard deviation, ppm: Parts per million, LOD: Limit of detection, LOQ: Limit of quantification. PMID:28539748

Rapid Development and Validation of Improved Reversed-Phase High-performance Liquid Chromatography Method for the Quantification of Mangiferin, a Polyphenol Xanthone Glycoside in Mangifera indica.

PubMed

Naveen, P; Lingaraju, H B; Prasad, K Shyam

2017-01-01

Mangiferin, a polyphenolic xanthone glycoside from Mangifera indica , is used as traditional medicine for the treatment of numerous diseases. The present study was aimed to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC) method for the quantification of mangiferin from the bark extract of M. indica . RP-HPLC analysis was performed by isocratic elution with a low-pressure gradient using 0.1% formic acid: acetonitrile (87:13) as a mobile phase with a flow rate of 1.5 ml/min. The separation was done at 26°C using a Kinetex XB-C18 column as stationary phase and the detection wavelength at 256 nm. The proposed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification, and robustness by the International Conference on Harmonisation guidelines. In linearity, the excellent correlation coefficient more than 0.999 indicated good fitting of the curve and also good linearity. The intra- and inter-day precision showed < 1% of relative standard deviation of peak area indicated high reliability and reproducibility of the method. The recovery values at three different levels (50%, 100%, and 150%) of spiked samples were found to be 100.47, 100.89, and 100.99, respectively, and low standard deviation value < 1% shows high accuracy of the method. In robustness, the results remain unaffected by small variation in the analytical parameters, which shows the robustness of the method. Liquid chromatography-mass spectrometry analysis confirmed the presence of mangiferin with M/Z value of 421. The assay developed by HPLC method is a simple, rapid, and reliable for the determination of mangiferin from M. indica . The present study was intended to develop and validate an RP-HPLC method for the quantification of mangiferin from the bark extract of M. indica . The developed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification and robustness by International Conference on Harmonization guidelines. This study proved that the developed assay by HPLC method is a simple, rapid and reliable for the quantification of the mangiferin from M. indica . Abbreviations Used: M. indica : Mangifera indica , RP-HPLC: Reversed-phase high-performance liquid chromatography, M/Z: Mass to charge ratio, ICH: International conference on harmonization, % RSD: Percentage of relative standard deviation, ppm: Parts per million, LOD: Limit of detection, LOQ: Limit of quantification.

Novel Strength Test Battery to Permit Evidence-Based Paralympic Classification

PubMed Central

Beckman, Emma M.; Newcombe, Peter; Vanlandewijck, Yves; Connick, Mark J.; Tweedy, Sean M.

2014-01-01

Abstract Ordinal-scale strength assessment methods currently used in Paralympic athletics classification prevent the development of evidence-based classification systems. This study evaluated a battery of 7, ratio-scale, isometric tests with the aim of facilitating the development of evidence-based methods of classification. This study aimed to report sex-specific normal performance ranges, evaluate test–retest reliability, and evaluate the relationship between the measures and body mass. Body mass and strength measures were obtained from 118 participants—63 males and 55 females—ages 23.2 years ± 3.7 (mean ± SD). Seventeen participants completed the battery twice to evaluate test–retest reliability. The body mass–strength relationship was evaluated using Pearson correlations and allometric exponents. Conventional patterns of force production were observed. Reliability was acceptable (mean intraclass correlation = 0.85). Eight measures had moderate significant correlations with body size (r = 0.30–61). Allometric exponents were higher in males than in females (mean 0.99 vs 0.30). Results indicate that this comprehensive and parsimonious battery is an important methodological advance because it has psychometric properties critical for the development of evidence-based classification. Measures were interrelated with body size, indicating further research is required to determine whether raw measures require normalization in order to be validly applied in classification. PMID:25068950

Design and validation of instruments to measure knowledge.

PubMed

Elliott, T E; Regal, R R; Elliott, B A; Renier, C M

2001-01-01

Measuring health care providers' learning after they have participated in educational interventions that use experimental designs requires valid, reliable, and practical instruments. A literature review was conducted. In addition, experience gained from designing and validating instruments for measuring the effect of an educational intervention informed this process. The eight main steps for designing, validating, and testing the reliability of instruments for measuring learning outcomes are presented. The key considerations and rationale for this process are discussed. Methods for critiquing and adapting existent instruments and creating new ones are offered. This study may help other investigators in developing valid, reliable, and practical instruments for measuring the outcomes of educational activities.

Reliability and Validity of the Dyadic Observed Communication Scale (DOCS).

PubMed

Hadley, Wendy; Stewart, Angela; Hunter, Heather L; Affleck, Katelyn; Donenberg, Geri; Diclemente, Ralph; Brown, Larry K

2013-02-01

We evaluated the reliability and validity of the Dyadic Observed Communication Scale (DOCS) coding scheme, which was developed to capture a range of communication components between parents and adolescents. Adolescents and their caregivers were recruited from mental health facilities for participation in a large, multi-site family-based HIV prevention intervention study. Seventy-one dyads were randomly selected from the larger study sample and coded using the DOCS at baseline. Preliminary validity and reliability of the DOCS was examined using various methods, such as comparing results to self-report measures and examining interrater reliability. Results suggest that the DOCS is a reliable and valid measure of observed communication among parent-adolescent dyads that captures both verbal and nonverbal communication behaviors that are typical intervention targets. The DOCS is a viable coding scheme for use by researchers and clinicians examining parent-adolescent communication. Coders can be trained to reliably capture individual and dyadic components of communication for parents and adolescents and this complex information can be obtained relatively quickly.

Development of the Sri Lankan early teenagers' violence inventory: an instrument to measure peer violence in schools.

PubMed

Wijeratne, Monika; Seneviratne, Rohini; Gunawardena, Nalika; Østbye, Truls; Lynch, Catherine; Sandøy, Ingvild Fossgard

2014-01-01

This study was designed to develop an inventory to measure peer violence among early teens (13-15 years of age) in schools in Sri Lanka. Development of SLETVI was carried out in two phases. In phase I, development of an operational definition for peer violence, identification, and finalizing violent acts for inventory was done by a combination of qualitative methods: a comprehensive literature review, focus group discussions among 13-15-year-old adolescents, their teachers and parents, and consultative meetings with experts in the field. Inventory was then pretested. In phase II, elaboration of SLETVI was carried out by administering it to a sample of 1700 adolescents (13-15 years old). Exploratory factor analysis using principal component analysis was performed separately for experiences of victimization and perpetration. Test-retest reliability of SLETVI was assessed. SLETVI included 37 items in three factors: "less severe violence," "severe physical," and "severe relational" violence. Combined use of qualitative and quantitative methods enabled development of a culturally valid and reliable operational inventory to assess early teenagers' peer violence in Sri Lankan and other South Asian schools.

A simple video-based timing system for on-ice team testing in ice hockey: a technical report.

PubMed

Larson, David P; Noonan, Benjamin C

2014-09-01

The purpose of this study was to describe and evaluate a newly developed on-ice timing system for team evaluation in the sport of ice hockey. We hypothesized that this new, simple, inexpensive, timing system would prove to be highly accurate and reliable. Six adult subjects (age 30.4 ± 6.2 years) performed on ice tests of acceleration and conditioning. The performance times of the subjects were recorded using a handheld stopwatch, photocell, and high-speed (240 frames per second) video. These results were then compared to allow for accuracy calculations of the stopwatch and video as compared with filtered photocell timing that was used as the "gold standard." Accuracy was evaluated using maximal differences, typical error/coefficient of variation (CV), and intraclass correlation coefficients (ICCs) between the timing methods. The reliability of the video method was evaluated using the same variables in a test-retest analysis both within and between evaluators. The video timing method proved to be both highly accurate (ICC: 0.96-0.99 and CV: 0.1-0.6% as compared with the photocell method) and reliable (ICC and CV within and between evaluators: 0.99 and 0.08%, respectively). This video-based timing method provides a very rapid means of collecting a high volume of very accurate and reliable on-ice measures of skating speed and conditioning, and can easily be adapted to other testing surfaces and parameters.

Optimal sample sizes for the design of reliability studies: power consideration.

PubMed

Shieh, Gwowen

2014-09-01

Intraclass correlation coefficients are used extensively to measure the reliability or degree of resemblance among group members in multilevel research. This study concerns the problem of the necessary sample size to ensure adequate statistical power for hypothesis tests concerning the intraclass correlation coefficient in the one-way random-effects model. In view of the incomplete and problematic numerical results in the literature, the approximate sample size formula constructed from Fisher's transformation is reevaluated and compared with an exact approach across a wide range of model configurations. These comprehensive examinations showed that the Fisher transformation method is appropriate only under limited circumstances, and therefore it is not recommended as a general method in practice. For advance design planning of reliability studies, the exact sample size procedures are fully described and illustrated for various allocation and cost schemes. Corresponding computer programs are also developed to implement the suggested algorithms.

Bayesian least squares deconvolution

NASA Astrophysics Data System (ADS)

Asensio Ramos, A.; Petit, P.

2015-11-01

Aims: We develop a fully Bayesian least squares deconvolution (LSD) that can be applied to the reliable detection of magnetic signals in noise-limited stellar spectropolarimetric observations using multiline techniques. Methods: We consider LSD under the Bayesian framework and we introduce a flexible Gaussian process (GP) prior for the LSD profile. This prior allows the result to automatically adapt to the presence of signal. We exploit several linear algebra identities to accelerate the calculations. The final algorithm can deal with thousands of spectral lines in a few seconds. Results: We demonstrate the reliability of the method with synthetic experiments and we apply it to real spectropolarimetric observations of magnetic stars. We are able to recover the magnetic signals using a small number of spectral lines, together with the uncertainty at each velocity bin. This allows the user to consider if the detected signal is reliable. The code to compute the Bayesian LSD profile is freely available.

Matrix suppression as a guideline for reliable quantification of peptides by matrix-assisted laser desorption ionization.

PubMed

Ahn, Sung Hee; Bae, Yong Jin; Moon, Jeong Hee; Kim, Myung Soo

2013-09-17

We propose to divide matrix suppression in matrix-assisted laser desorption ionization into two parts, normal and anomalous. In quantification of peptides, the normal effect can be accounted for by constructing the calibration curve in the form of peptide-to-matrix ion abundance ratio versus concentration. The anomalous effect forbids reliable quantification and is noticeable when matrix suppression is larger than 70%. With this 70% rule, matrix suppression becomes a guideline for reliable quantification, rather than a nuisance. A peptide in a complex mixture can be quantified even in the presence of large amounts of contaminants, as long as matrix suppression is below 70%. The theoretical basis for the quantification method using a peptide as an internal standard is presented together with its weaknesses. A systematic method to improve quantification of high concentration analytes has also been developed.

Development of a Tandem Repeat-Based Polymerase Chain Displacement Reaction Method for Highly Sensitive Detection of 'Candidatus Liberibacter asiaticus'.

PubMed

Lou, Binghai; Song, Yaqin; RoyChowdhury, Moytri; Deng, Chongling; Niu, Ying; Fan, Qijun; Tang, Yan; Zhou, Changyong

2018-02-01

Huanglongbing (HLB) is one of the most destructive diseases in citrus production worldwide. Early detection of HLB pathogens can facilitate timely removal of infected citrus trees in the field. However, low titer and uneven distribution of HLB pathogens in host plants make reliable detection challenging. Therefore, the development of effective detection methods with high sensitivity is imperative. This study reports the development of a novel method, tandem repeat-based polymerase chain displacement reaction (TR-PCDR), for the detection of 'Candidatus Liberibacter asiaticus', a widely distributed HLB-associated bacterium. A uniquely designed primer set (TR2-PCDR-F/TR2-PCDR-1R) and a thermostable Taq DNA polymerase mutant with strand displacement activity were used for TR-PCDR amplification. Performed in a regular thermal cycler, TR-PCDR could produce more than two amplicons after each amplification cycle. Sensitivity of the developed TR-PCDR was 10 copies of target DNA fragment. The sensitive level was proven to be 100× higher than conventional PCR and similar to real-time PCR. Data from the detection of 'Ca. L. asiaticus' with filed samples using the above three methods also showed similar results. No false-positive TR-PCDR amplification was observed from healthy citrus samples and water controls. These results thereby illustrated that the developed TR-PCDR method can be applied to the reliable, highly sensitive, and cost-effective detection of 'Ca. L. asiaticus'.

A simple and reliable multi-gene transformation method for switchgrass.

PubMed

Ogawa, Yoichi; Shirakawa, Makoto; Koumoto, Yasuko; Honda, Masaho; Asami, Yuki; Kondo, Yasuhiro; Hara-Nishimura, Ikuko

2014-07-01

A simple and reliable Agrobacterium -mediated transformation method was developed for switchgrass. Using this method, many transgenic plants carrying multiple genes-of-interest could be produced without untransformed escape. Switchgrass (Panicum virgatum L.) is a promising biomass crop for bioenergy. To obtain transgenic switchgrass plants carrying a multi-gene trait in a simple manner, an Agrobacterium-mediated transformation method was established by constructing a Gateway-based binary vector, optimizing transformation conditions and developing a novel selection method. A MultiRound Gateway-compatible destination binary vector carrying the bar selectable marker gene, pHKGB110, was constructed to introduce multiple genes of interest in a single transformation. Two reporter gene expression cassettes, GUSPlus and gfp, were constructed independently on two entry vectors and then introduced into a single T-DNA region of pHKGB110 via sequential LR reactions. Agrobacterium tumefaciens EHA101 carrying the resultant binary vector pHKGB112 and caryopsis-derived compact embryogenic calli were used for transformation experiments. Prolonged cocultivation for 7 days followed by cultivation on media containing meropenem improved transformation efficiency without overgrowth of Agrobacterium, which was, however, not inhibited by cefotaxime or Timentin. In addition, untransformed escape shoots were completely eliminated during the rooting stage by direct dipping the putatively transformed shoots into the herbicide Basta solution for a few seconds, designated as the 'herbicide dipping method'. It was also demonstrated that more than 90 % of the bar-positive transformants carried both reporters delivered from pHKGB112. This simple and reliable transformation method, which incorporates a new selection technique and the use of a MultiRound Gateway-based binary vector, would be suitable for producing a large number of transgenic lines carrying multiple genes.

Web-video-mining-supported workflow modeling for laparoscopic surgeries.

PubMed

Liu, Rui; Zhang, Xiaoli; Zhang, Hao

2016-11-01

As quality assurance is of strong concern in advanced surgeries, intelligent surgical systems are expected to have knowledge such as the knowledge of the surgical workflow model (SWM) to support their intuitive cooperation with surgeons. For generating a robust and reliable SWM, a large amount of training data is required. However, training data collected by physically recording surgery operations is often limited and data collection is time-consuming and labor-intensive, severely influencing knowledge scalability of the surgical systems. The objective of this research is to solve the knowledge scalability problem in surgical workflow modeling with a low cost and labor efficient way. A novel web-video-mining-supported surgical workflow modeling (webSWM) method is developed. A novel video quality analysis method based on topic analysis and sentiment analysis techniques is developed to select high-quality videos from abundant and noisy web videos. A statistical learning method is then used to build the workflow model based on the selected videos. To test the effectiveness of the webSWM method, 250 web videos were mined to generate a surgical workflow for the robotic cholecystectomy surgery. The generated workflow was evaluated by 4 web-retrieved videos and 4 operation-room-recorded videos, respectively. The evaluation results (video selection consistency n-index ≥0.60; surgical workflow matching degree ≥0.84) proved the effectiveness of the webSWM method in generating robust and reliable SWM knowledge by mining web videos. With the webSWM method, abundant web videos were selected and a reliable SWM was modeled in a short time with low labor cost. Satisfied performances in mining web videos and learning surgery-related knowledge show that the webSWM method is promising in scaling knowledge for intelligent surgical systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Developing a Vocational Index for Adults with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Taylor, Julie Lounds; Seltzer, Marsha Mailick

2012-01-01

Existing methods of indexing the vocational activities of adults with autism spectrum disorders (ASD) have made significant contributions to research. Nonetheless, they are limited by problems with sensitivity and reliability. We developed an index of vocational and educational outcomes that captures the full range of activities experienced by…

Statistical control in hydrologic forecasting.

Treesearch

H.G. Wilm

1950-01-01

With rapidly growing development and uses of water, a correspondingly great demand has developed for advance estimates of the volumes or rates of flow which are supplied by streams. Therefore much attention is being devoted to hydrologic forecasting, and numerous methods have been tested in efforts to make increasingly reliable estimates of future supplies.

78 FR 48422 - Agency Information Collection Activities: Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-08

... quantitative data through surveys with working-age (age 18-61) and older American (age 62 and older) consumers in order to develop and refine survey instruments that will enable the CFPB to reliably and... conducting research to identify methods and strategies to educate and counsel seniors, and developing goals...

Developing and validating the Communication Function Classification System for individuals with cerebral palsy

PubMed Central

HIDECKER, MARY JO COOLEY; PANETH, NIGEL; ROSENBAUM, PETER L; KENT, RAYMOND D; LILLIE, JANET; EULENBERG, JOHN B; CHESTER, KEN; JOHNSON, BRENDA; MICHALSEN, LAUREN; EVATT, MORGAN; TAYLOR, KARA

2011-01-01

Aim The purpose of this study was to create and validate a Communication Function Classification System (CFCS) for children with cerebral palsy (CP) that can be used by a wide variety of individuals who are interested in CP. This paper reports the content validity, interrater reliability, and test–retest reliability of the CFCS for children with CP. Method An 11-member development team created comprehensive descriptions of the CFCS levels, and four nominal groups comprising 27 participants critiqued these levels. Within a Delphi survey, 112 participants commented on the clarity and usefulness of the CFCS. Interrater reliability was completed by 61 professionals and 68 parents/relatives who classified 69 children with CP aged 2 to 18 years. Test–retest reliability was completed by 48 professionals who allowed at least 2 weeks between classifications. The participants who assessed the CFCS were all relevant stakeholders: adults with CP, parents of children with CP, educators, occupational therapists, physical therapists, physicians, and speech–language pathologists. Results The interrater reliability of the CFCS was 0.66 between two professionals and 0.49 between a parent and a professional. Professional interrater reliability improved to 0.77 for classification of children older than 4 years. The test–retest reliability was 0.82. Interpretation The CFCS demonstrates content validity and shows very good test–retest reliability, good professional interrater reliability, and moderate parent–professional interrater reliability. Combining the CFCS with the Gross Motor Function Classification System and the Manual Ability Classification System contributes to a functional performance view of daily life for individuals with CP, in accordance with the World Health Organization’s International Classification of Functioning, Disability and Health. PMID:21707596

Prospective patients rate practice factors: development of a questionnaire.

PubMed

St Louis, Brian Lingg; Firestone, Allen R; Johnston, William; Shanker, Shiva; Vig, Katherine W L

2011-02-01

The importance that prospective patients place on practice characteristics when choosing an orthodontic practice has not been extensively reported. The objective of this research was to develop a valid and reliable questionnaire to address the relative importance of orthodontic office and doctor characteristics for prospective patients or parents of child patients during the initial orthodontic office consultation. An initial questionnaire, based on published literature, was field-tested on 16 subjects to assess its validity. Based on the field test, the questionnaire was modified and tested for reliability by using a test-retest method. The questionnaire covered the following areas: doctor, office, staff, and finances. The reliability study included 2 groups of subjects: 12 consecutive prospective adult patients and 41 consecutive parents of prospective child patients. The questionnaires consisted of 43 and 50 questions for the adult patients and the parents of patients, respectively. The subjects rated the importance of practice characteristics in their selection of an orthodontic practice using a 100-mm visual analog scale anchored at "not important at all" and "most important." Reliability was analyzed by using the intraclass correlation coefficient (ICC). Summary scores of all 53 subjects showed excellent reliability (ICC, 0.88; range, 0.61-1.0). Summary scores of all 50 questions showed acceptable reliability (ICC, 0.70; range, 0.45-0.88). Twenty-one questions had excellent reliability (ICC, >.75), and 29 questions had fair-to-good reliability (ICC, 0.41-0.75). No questions showed poor reliability (ICC, <0.4). The pilot study data indicated that the overall reliability of the questionnaire is acceptable. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Beyond the Condom: Frontiers in Male Contraception

PubMed Central

Roth, Mara Y.; Amory, John K.

2016-01-01

Nearly half of all pregnancies worldwide are unplanned, despite numerous contraceptive options available. No new contraceptive method has been developed for men since the invention of condom. Nevertheless, more than 25% of contraception worldwide relies on male methods. Therefore, novel effective methods of male contraception are of interest. Herein we review the physiologic basis for both male hormonal and nonhormonal methods of contraception. We review the history of male hormonal contraception development, current hormonal agents in development, as well as the potential risks and benefits of male hormonal contraception options for men. Nonhormonal methods reviewed will include both pharmacological and mechanical approaches in development, with specific focus on methods which inhibit the testicular retinoic acid synthesis and action. Multiple hormonal and nonhormonal methods of male contraception are in the drug development pathway, with the hope that a reversible, reliable, safe method of male contraception will be available to couples in the not too distant future. PMID:26947703

Validity and Reliability of the Turkish Chronic Pain Acceptance Questionnaire

PubMed Central

Akmaz, Hazel Ekin; Uyar, Meltem; Kuzeyli Yıldırım, Yasemin; Akın Korhan, Esra

2018-01-01

Background: Pain acceptance is the process of giving up the struggle with pain and learning to live a worthwhile life despite it. In assessing patients with chronic pain in Turkey, making a diagnosis and tracking the effectiveness of treatment is done with scales that have been translated into Turkish. However, there is as yet no valid and reliable scale in Turkish to assess the acceptance of pain. Aims: To validate a Turkish version of the Chronic Pain Acceptance Questionnaire developed by McCracken and colleagues. Study Design: Methodological and cross sectional study. Methods: A simple randomized sampling method was used in selecting the study sample. The sample was composed of 201 patients, more than 10 times the number of items examined for validity and reliability in the study, which totaled 20. A patient identification form, the Chronic Pain Acceptance Questionnaire, and the Brief Pain Inventory were used to collect data. Data were collected by face-to-face interviews. In the validity testing, the content validity index was used to evaluate linguistic equivalence, content validity, construct validity, and expert views. In reliability testing of the scale, Cronbach’s α coefficient was calculated, and item analysis and split-test reliability methods were used. Principal component analysis and varimax rotation were used in factor analysis and to examine factor structure for construct concept validity. Results: The item analysis established that the scale, all items, and item-total correlations were satisfactory. The mean total score of the scale was 21.78. The internal consistency coefficient was 0.94, and the correlation between the two halves of the scale was 0.89. Conclusion: The Chronic Pain Acceptance Questionnaire, which is intended to be used in Turkey upon confirmation of its validity and reliability, is an evaluation instrument with sufficient validity and reliability, and it can be reliably used to examine patients’ acceptance of chronic pain. PMID:29843496

Development and psychometric evaluation of an information literacy self-efficacy survey and an information literacy knowledge test*

PubMed Central

Tepe, Rodger; Tepe, Chabha

2015-01-01

Objective To develop and psychometrically evaluate an information literacy (IL) self-efficacy survey and an IL knowledge test. Methods In this test–retest reliability study, a 25-item IL self-efficacy survey and a 50-item IL knowledge test were developed and administered to a convenience sample of 53 chiropractic students. Item analyses were performed on all questions. Results The IL self-efficacy survey demonstrated good reliability (test–retest correlation = 0.81) and good/very good internal consistency (mean κ = .56 and Cronbach's α = .92). A total of 25 questions with the best item analysis characteristics were chosen from the 50-item IL knowledge test, resulting in a 25-item IL knowledge test that demonstrated good reliability (test–retest correlation = 0.87), very good internal consistency (mean κ = .69, KR20 = 0.85), and good item discrimination (mean point-biserial = 0.48). Conclusions This study resulted in the development of three instruments: a 25-item IL self-efficacy survey, a 50-item IL knowledge test, and a 25-item IL knowledge test. The information literacy self-efficacy survey and the 25-item version of the information literacy knowledge test have shown preliminary evidence of adequate reliability and validity to justify continuing study with these instruments. PMID:25517736

Laser notching ceramics for reliable fracture toughness testing

DOE PAGES

Barth, Holly D.; Elmer, John W.; Freeman, Dennis C.; ...

2015-09-19

A new method for notching ceramics was developed using a picosecond laser for fracture toughness testing of alumina samples. The test geometry incorporated a single-edge-V-notch that was notched using picosecond laser micromachining. This method has been used in the past for cutting ceramics, and is known to remove material with little to no thermal effect on the surrounding material matrix. This study showed that laser-assisted-machining for fracture toughness testing of ceramics was reliable, quick, and cost effective. In order to assess the laser notched single-edge-V-notch beam method, fracture toughness results were compared to results from other more traditional methods, specificallymore » surface-crack in flexure and the chevron notch bend tests. Lastly, the results showed that picosecond laser notching produced precise notches in post-failure measurements, and that the measured fracture toughness results showed improved consistency compared to traditional fracture toughness methods.« less

Reliability-based design optimization using a generalized subset simulation method and posterior approximation

NASA Astrophysics Data System (ADS)

Ma, Yuan-Zhuo; Li, Hong-Shuang; Yao, Wei-Xing

2018-05-01

The evaluation of the probabilistic constraints in reliability-based design optimization (RBDO) problems has always been significant and challenging work, which strongly affects the performance of RBDO methods. This article deals with RBDO problems using a recently developed generalized subset simulation (GSS) method and a posterior approximation approach. The posterior approximation approach is used to transform all the probabilistic constraints into ordinary constraints as in deterministic optimization. The assessment of multiple failure probabilities required by the posterior approximation approach is achieved by GSS in a single run at all supporting points, which are selected by a proper experimental design scheme combining Sobol' sequences and Bucher's design. Sequentially, the transformed deterministic design optimization problem can be solved by optimization algorithms, for example, the sequential quadratic programming method. Three optimization problems are used to demonstrate the efficiency and accuracy of the proposed method.

Agent autonomy approach to probabilistic physics-of-failure modeling of complex dynamic systems with interacting failure mechanisms

NASA Astrophysics Data System (ADS)

Gromek, Katherine Emily

A novel computational and inference framework of the physics-of-failure (PoF) reliability modeling for complex dynamic systems has been established in this research. The PoF-based reliability models are used to perform a real time simulation of system failure processes, so that the system level reliability modeling would constitute inferences from checking the status of component level reliability at any given time. The "agent autonomy" concept is applied as a solution method for the system-level probabilistic PoF-based (i.e. PPoF-based) modeling. This concept originated from artificial intelligence (AI) as a leading intelligent computational inference in modeling of multi agents systems (MAS). The concept of agent autonomy in the context of reliability modeling was first proposed by M. Azarkhail [1], where a fundamentally new idea of system representation by autonomous intelligent agents for the purpose of reliability modeling was introduced. Contribution of the current work lies in the further development of the agent anatomy concept, particularly the refined agent classification within the scope of the PoF-based system reliability modeling, new approaches to the learning and the autonomy properties of the intelligent agents, and modeling interacting failure mechanisms within the dynamic engineering system. The autonomous property of intelligent agents is defined as agent's ability to self-activate, deactivate or completely redefine their role in the analysis. This property of agents and the ability to model interacting failure mechanisms of the system elements makes the agent autonomy fundamentally different from all existing methods of probabilistic PoF-based reliability modeling. 1. Azarkhail, M., "Agent Autonomy Approach to Physics-Based Reliability Modeling of Structures and Mechanical Systems", PhD thesis, University of Maryland, College Park, 2007.

Reliability of digital reactor protection system based on extenics.

PubMed

Zhao, Jing; He, Ya-Nan; Gu, Peng-Fei; Chen, Wei-Hua; Gao, Feng

2016-01-01

After the Fukushima nuclear accident, safety of nuclear power plants (NPPs) is widespread concerned. The reliability of reactor protection system (RPS) is directly related to the safety of NPPs, however, it is difficult to accurately evaluate the reliability of digital RPS. The method is based on estimating probability has some uncertainties, which can not reflect the reliability status of RPS dynamically and support the maintenance and troubleshooting. In this paper, the reliability quantitative analysis method based on extenics is proposed for the digital RPS (safety-critical), by which the relationship between the reliability and response time of RPS is constructed. The reliability of the RPS for CPR1000 NPP is modeled and analyzed by the proposed method as an example. The results show that the proposed method is capable to estimate the RPS reliability effectively and provide support to maintenance and troubleshooting of digital RPS system.

Moving human full body and body parts detection, tracking, and applications on human activity estimation, walking pattern and face recognition

NASA Astrophysics Data System (ADS)

Chen, Hai-Wen; McGurr, Mike

2016-05-01

We have developed a new way for detection and tracking of human full-body and body-parts with color (intensity) patch morphological segmentation and adaptive thresholding for security surveillance cameras. An adaptive threshold scheme has been developed for dealing with body size changes, illumination condition changes, and cross camera parameter changes. Tests with the PETS 2009 and 2014 datasets show that we can obtain high probability of detection and low probability of false alarm for full-body. Test results indicate that our human full-body detection method can considerably outperform the current state-of-the-art methods in both detection performance and computational complexity. Furthermore, in this paper, we have developed several methods using color features for detection and tracking of human body-parts (arms, legs, torso, and head, etc.). For example, we have developed a human skin color sub-patch segmentation algorithm by first conducting a RGB to YIQ transformation and then applying a Subtractive I/Q image Fusion with morphological operations. With this method, we can reliably detect and track human skin color related body-parts such as face, neck, arms, and legs. Reliable body-parts (e.g. head) detection allows us to continuously track the individual person even in the case that multiple closely spaced persons are merged. Accordingly, we have developed a new algorithm to split a merged detection blob back to individual detections based on the detected head positions. Detected body-parts also allow us to extract important local constellation features of the body-parts positions and angles related to the full-body. These features are useful for human walking gait pattern recognition and human pose (e.g. standing or falling down) estimation for potential abnormal behavior and accidental event detection, as evidenced with our experimental tests. Furthermore, based on the reliable head (face) tacking, we have applied a super-resolution algorithm to enhance the face resolution for improved human face recognition performance.

The validation of Huffaz Intelligence Test (HIT)

NASA Astrophysics Data System (ADS)

Rahim, Mohd Azrin Mohammad; Ahmad, Tahir; Awang, Siti Rahmah; Safar, Ajmain

2017-08-01

In general, a hafiz who can memorize the Quran has many specialties especially in respect to their academic performances. In this study, the theory of multiple intelligences introduced by Howard Gardner is embedded in a developed psychometric instrument, namely Huffaz Intelligence Test (HIT). This paper presents the validation and the reliability of HIT of some tahfiz students in Malaysia Islamic schools. A pilot study was conducted involving 87 huffaz who were randomly selected to answer the items in HIT. The analysis method used includes Partial Least Square (PLS) on reliability, convergence and discriminant validation. The study has validated nine intelligences. The findings also indicated that the composite reliabilities for the nine types of intelligences are greater than 0.8. Thus, the HIT is a valid and reliable instrument to measure the multiple intelligences among huffaz.

Engineering Design Handbook. Development Guide for Reliability. Part Two. Design for Reliability

DTIC Science & Technology

1976-01-01

Component failure rates, however, have been recorded by many sources as a function of use and environment. Some of these sources are listed in Refs. 13-17...other systems capable of creating an explosive reac- tion. The second category is fairly obvious and includes many variations on methods for providing...aboutthem. 4. Ability to detect signals ( including patterns) in high noise environments. 5. Ability to store large amounts of informa- tion for long

Research strategies that result in optimal data collection from the patient medical record

PubMed Central

Gregory, Katherine E.; Radovinsky, Lucy

2010-01-01

Data obtained from the patient medical record are often a component of clinical research led by nurse investigators. The rigor of the data collection methods correlates to the reliability of the data and, ultimately, the analytical outcome of the study. Research strategies for reliable data collection from the patient medical record include the development of a precise data collection tool, the use of a coding manual, and ongoing communication with research staff. PMID:20974093

An experimental evaluation of software redundancy as a strategy for improving reliability

NASA Technical Reports Server (NTRS)

Eckhardt, Dave E., Jr.; Caglayan, Alper K.; Knight, John C.; Lee, Larry D.; Mcallister, David F.; Vouk, Mladen A.; Kelly, John P. J.

1990-01-01

The strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is suggested by the success of hardware redundancy for tolerating hardware failures. Although, as generally accepted, the independence of hardware failures resulting from physical wearout can lead to substantial increases in reliability for redundant hardware structures, a similar conclusion is not immediate for software. The degree to which design faults are manifested as independent failures determines the effectiveness of redundancy as a method for improving software reliability. Interest in multi-version software centers on whether it provides an adequate measure of increased reliability to warrant its use in critical applications. The effectiveness of multi-version software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with estimates obtained when failures are assumed to be independent. The experimental results are based on twenty versions of an aerospace application developed and certified by sixty programmers from four universities. Descriptions of the application, development and certification processes, and operational evaluation are given together with an analysis of the twenty versions.

R&D of high reliable refrigeration system for superconducting generators

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

Hosoya, T.; Shindo, S.; Yaguchi, H.

1996-12-31

Super-GM carries out R&D of 70 MW class superconducting generators (model machines), refrigeration system and superconducting wires to apply superconducting technology to electric power apparatuses. The helium refrigeration system for keeping field windings of superconducting generator (SCG) in cryogenic environment must meet the requirement of high reliability for uninterrupted long term operation of the SCG. In FY 1992, a high reliable conventional refrigeration system for the model machines was integrated by combining components such as compressor unit, higher temperature cold box and lower temperature cold box which were manufactured utilizing various fundamental technologies developed in early stage of the projectmore » since 1988. Since FY 1993, its performance tests have been carried out. It has been confirmed that its performance was fulfilled the development target of liquefaction capacity of 100 L/h and impurity removal in the helium gas to < 0.1 ppm. Furthermore, its operation method and performance were clarified to all different modes as how to control liquefaction rate and how to supply liquid helium from a dewar to the model machine. In addition, the authors have made performance tests and system performance analysis of oil free screw type and turbo type compressors which greatly improve reliability of conventional refrigeration systems. The operation performance and operational control method of the compressors has been clarified through the tests and analysis.« less

A simplified high-throughput method for pyrethroid knock-down resistance (kdr) detection in Anopheles gambiae

PubMed Central

Lynd, Amy; Ranson, Hilary; McCall, P J; Randle, Nadine P; Black, William C; Walker, Edward D; Donnelly, Martin J

2005-01-01

Background A single base pair mutation in the sodium channel confers knock-down resistance to pyrethroids in many insect species. Its occurrence in Anopheles mosquitoes may have important implications for malaria vector control especially considering the current trend for large scale pyrethroid-treated bednet programmes. Screening Anopheles gambiae populations for the kdr mutation has become one of the mainstays of programmes that monitor the development of insecticide resistance. The screening is commonly performed using a multiplex Polymerase Chain Reaction (PCR) which, since it is reliant on a single nucleotide polymorphism, can be unreliable. Here we present a reliable and potentially high throughput method for screening An. gambiae for the kdr mutation. Methods A Hot Ligation Oligonucleotide Assay (HOLA) was developed to detect both the East and West African kdr alleles in the homozygous and heterozygous states, and was optimized for use in low-tech developing world laboratories. Results from the HOLA were compared to results from the multiplex PCR for field and laboratory mosquito specimens to provide verification of the robustness and sensitivity of the technique. Results and Discussion The HOLA assay, developed for detection of the kdr mutation, gives a bright blue colouration for a positive result whilst negative reactions remain colourless. The results are apparent within a few minutes of adding the final substrate and can be scored by eye. Heterozygotes are scored when a sample gives a positive reaction to the susceptible probe and the kdr probe. The technique uses only basic laboratory equipment and skills and can be carried out by anyone familiar with the Enzyme-linked immunosorbent assay (ELISA) technique. A comparison to the multiplex PCR method showed that the HOLA assay was more reliable, and scoring of the plates was less ambiguous. Conclusion The method is capable of detecting both the East and West African kdr alleles in the homozygous and heterozygous states from fresh or dried material using several DNA extraction methods. It is more reliable than the traditional PCR method and may be more sensitive for the detection of heterozygotes. It is inexpensive, simple and relatively safe making it suitable for use in resource-poor countries. PMID:15766386

Creep-rupture reliability analysis

NASA Technical Reports Server (NTRS)

Peralta-Duran, A.; Wirsching, P. H.

1984-01-01

A probabilistic approach to the correlation and extrapolation of creep-rupture data is presented. Time temperature parameters (TTP) are used to correlate the data, and an analytical expression for the master curve is developed. The expression provides a simple model for the statistical distribution of strength and fits neatly into a probabilistic design format. The analysis focuses on the Larson-Miller and on the Manson-Haferd parameters, but it can be applied to any of the TTP's. A method is developed for evaluating material dependent constants for TTP's. It is shown that optimized constants can provide a significant improvement in the correlation of the data, thereby reducing modelling error. Attempts were made to quantify the performance of the proposed method in predicting long term behavior. Uncertainty in predicting long term behavior from short term tests was derived for several sets of data. Examples are presented which illustrate the theory and demonstrate the application of state of the art reliability methods to the design of components under creep.

Development of a computer-assisted forensic radiographic identification method using the lateral cervical and lumbar spine.

PubMed

Derrick, Sharon M; Raxter, Michelle H; Hipp, John A; Goel, Priya; Chan, Elaine F; Love, Jennifer C; Wiersema, Jason M; Akella, N Shastry

2015-01-01

Medical examiners and coroners (ME/C) in the United States hold statutory responsibility to identify deceased individuals who fall under their jurisdiction. The computer-assisted decedent identification (CADI) project was designed to modify software used in diagnosis and treatment of spinal injuries into a mathematically validated tool for ME/C identification of fleshed decedents. CADI software analyzes the shapes of targeted vertebral bodies imaged in an array of standard radiographs and quantifies the likelihood that any two of the radiographs contain matching vertebral bodies. Six validation tests measured the repeatability, reliability, and sensitivity of the method, and the effects of age, sex, and number of radiographs in array composition. CADI returned a 92-100% success rate in identifying the true matching pair of vertebrae within arrays of five to 30 radiographs. Further development of CADI is expected to produce a novel identification method for use in ME/C offices that is reliable, timely, and cost-effective. © 2014 American Academy of Forensic Sciences.

Advancing Usability Evaluation through Human Reliability Analysis

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

Ronald L. Boring; David I. Gertman

2005-07-01

This paper introduces a novel augmentation to the current heuristic usability evaluation methodology. The SPAR-H human reliability analysis method was developed for categorizing human performance in nuclear power plants. Despite the specialized use of SPAR-H for safety critical scenarios, the method also holds promise for use in commercial off-the-shelf software usability evaluations. The SPAR-H method shares task analysis underpinnings with human-computer interaction, and it can be easily adapted to incorporate usability heuristics as performance shaping factors. By assigning probabilistic modifiers to heuristics, it is possible to arrive at the usability error probability (UEP). This UEP is not a literal probabilitymore » of error but nonetheless provides a quantitative basis to heuristic evaluation. When combined with a consequence matrix for usability errors, this method affords ready prioritization of usability issues.« less

Modification site localization scoring integrated into a search engine.

PubMed

Baker, Peter R; Trinidad, Jonathan C; Chalkley, Robert J

2011-07-01

Large proteomic data sets identifying hundreds or thousands of modified peptides are becoming increasingly common in the literature. Several methods for assessing the reliability of peptide identifications both at the individual peptide or data set level have become established. However, tools for measuring the confidence of modification site assignments are sparse and are not often employed. A few tools for estimating phosphorylation site assignment reliabilities have been developed, but these are not integral to a search engine, so require a particular search engine output for a second step of processing. They may also require use of a particular fragmentation method and are mostly only applicable for phosphorylation analysis, rather than post-translational modifications analysis in general. In this study, we present the performance of site assignment scoring that is directly integrated into the search engine Protein Prospector, which allows site assignment reliability to be automatically reported for all modifications present in an identified peptide. It clearly indicates when a site assignment is ambiguous (and if so, between which residues), and reports an assignment score that can be translated into a reliability measure for individual site assignments.

Reliability history of the Apollo guidance computer

NASA Technical Reports Server (NTRS)

Hall, E. C.

1972-01-01

The Apollo guidance computer was designed to provide the computation necessary for guidance, navigation and control of the command module and the lunar landing module of the Apollo spacecraft. The computer was designed using the technology of the early 1960's and the production was completed by 1969. During the development, production, and operational phase of the program, the computer has accumulated a very interesting history which is valuable for evaluating the technology, production methods, system integration, and the reliability of the hardware. The operational experience in the Apollo guidance systems includes 17 computers which flew missions and another 26 flight type computers which are still in various phases of prelaunch activity including storage, system checkout, prelaunch spacecraft checkout, etc. These computers were manufactured and maintained under very strict quality control procedures with requirements for reporting and analyzing all indications of failure. Probably no other computer or electronic equipment with equivalent complexity has been as well documented and monitored. Since it has demonstrated a unique reliability history, it is important to evaluate the techniques and methods which have contributed to the high reliability of this computer.

DEVELOPMENTAL PALEOBIOLOGY OF THE VERTEBRATE SKELETON.

PubMed

Rücklin, Martin; Donoghue, Philip C J; Cunningham, John A; Marone, Federica; Stampanoni, Marco

2014-07-01

Studies of the development of organisms can reveal crucial information on homology of structures. Developmental data are not peculiar to living organisms, and they are routinely preserved in the mineralized tissues that comprise the vertebrate skeleton, allowing us to obtain direct insight into the developmental evolution of this most formative of vertebrate innovations. The pattern of developmental processes is recorded in fossils as successive stages inferred from the gross morphology of multiple specimens and, more reliably and routinely, through the ontogenetic stages of development seen in the skeletal histology of individuals. Traditional techniques are destructive and restricted to a 2-D plane with the third dimension inferred. Effective non-invasive methods of visualizing paleohistology to reconstruct developmental stages of the skeleton are necessary. In a brief survey of paleohistological techniques we discuss the pros and cons of these methods. The use of tomographic methods to reconstruct development of organs is exemplified by the study of the placoderm dentition. Testing evidence for the presence of teeth in placoderms, the first jawed vertebrates, we compare the methods that have been used. These include inferring the development from morphology, and using serial sectioning, microCT or synchrotron X-ray tomographic microscopy (SRXTM) to reconstruct growth stages and directions of growth. The ensuing developmental interpretations are biased by the methods and degree of inference. The most direct and reliable method is using SRXTM data to trace sclerochronology. The resulting developmental data can be used to resolve homology and test hypotheses on the origin of evolutionary novelties.

Organizational readiness for implementing change: a psychometric assessment of a new measure

PubMed Central

2014-01-01

Background Organizational readiness for change in healthcare settings is an important factor in successful implementation of new policies, programs, and practices. However, research on the topic is hindered by the absence of a brief, reliable, and valid measure. Until such a measure is developed, we cannot advance scientific knowledge about readiness or provide evidence-based guidance to organizational leaders about how to increase readiness. This article presents results of a psychometric assessment of a new measure called Organizational Readiness for Implementing Change (ORIC), which we developed based on Weiner’s theory of organizational readiness for change. Methods We conducted four studies to assess the psychometric properties of ORIC. In study one, we assessed the content adequacy of the new measure using quantitative methods. In study two, we examined the measure’s factor structure and reliability in a laboratory simulation. In study three, we assessed the reliability and validity of an organization-level measure of readiness based on aggregated individual-level data from study two. In study four, we conducted a small field study utilizing the same analytic methods as in study three. Results Content adequacy assessment indicated that the items developed to measure change commitment and change efficacy reflected the theoretical content of these two facets of organizational readiness and distinguished the facets from hypothesized determinants of readiness. Exploratory and confirmatory factor analysis in the lab and field studies revealed two correlated factors, as expected, with good model fit and high item loadings. Reliability analysis in the lab and field studies showed high inter-item consistency for the resulting individual-level scales for change commitment and change efficacy. Inter-rater reliability and inter-rater agreement statistics supported the aggregation of individual level readiness perceptions to the organizational level of analysis. Conclusions This article provides evidence in support of the ORIC measure. We believe this measure will enable testing of theories about determinants and consequences of organizational readiness and, ultimately, assist healthcare leaders to reduce the number of health organization change efforts that do not achieve desired benefits. Although ORIC shows promise, further assessment is needed to test for convergent, discriminant, and predictive validity. PMID:24410955

An Efficient Variable Screening Method for Effective Surrogate Models for Reliability-Based Design Optimization

DTIC Science & Technology

2014-04-01

surrogate model generation is difficult for high -dimensional problems, due to the curse of dimensionality. Variable screening methods have been...a variable screening model was developed for the quasi-molecular treatment of ion-atom collision [16]. In engineering, a confidence interval of...for high -level radioactive waste [18]. Moreover, the design sensitivity method can be extended to the variable screening method because vital

Assessment of College and University Campus Tobacco-Free Policies in North Carolina

ERIC Educational Resources Information Center

Lee, Joseph G. L.; Goldstein, Adam O.; Klein, Elizabeth G.; Ranney, Leah M.; Carver, Ashlea M.

2012-01-01

Objective: To develop a reliable and efficient method for assessing prevalence and strength of college/university tobacco-related policies. Participants: North Carolina (NC) public universities, community colleges, and private colleges/universities (N = 110). Methods: A census of policies using campus handbooks and Web sites was conducted in March…

Method matters: Understanding diagnostic reliability in DSM-IV and DSM-5.

PubMed

Chmielewski, Michael; Clark, Lee Anna; Bagby, R Michael; Watson, David

2015-08-01

Diagnostic reliability is essential for the science and practice of psychology, in part because reliability is necessary for validity. Recently, the DSM-5 field trials documented lower diagnostic reliability than past field trials and the general research literature, resulting in substantial criticism of the DSM-5 diagnostic criteria. Rather than indicating specific problems with DSM-5, however, the field trials may have revealed long-standing diagnostic issues that have been hidden due to a reliance on audio/video recordings for estimating reliability. We estimated the reliability of DSM-IV diagnoses using both the standard audio-recording method and the test-retest method used in the DSM-5 field trials, in which different clinicians conduct separate interviews. Psychiatric patients (N = 339) were diagnosed using the SCID-I/P; 218 were diagnosed a second time by an independent interviewer. Diagnostic reliability using the audio-recording method (N = 49) was "good" to "excellent" (M κ = .80) and comparable to the DSM-IV field trials estimates. Reliability using the test-retest method (N = 218) was "poor" to "fair" (M κ = .47) and similar to DSM-5 field-trials' estimates. Despite low test-retest diagnostic reliability, self-reported symptoms were highly stable. Moreover, there was no association between change in self-report and change in diagnostic status. These results demonstrate the influence of method on estimates of diagnostic reliability. (c) 2015 APA, all rights reserved).

Towards early software reliability prediction for computer forensic tools (case study).

PubMed

Abu Talib, Manar

2016-01-01

Versatility, flexibility and robustness are essential requirements for software forensic tools. Researchers and practitioners need to put more effort into assessing this type of tool. A Markov model is a robust means for analyzing and anticipating the functioning of an advanced component based system. It is used, for instance, to analyze the reliability of the state machines of real time reactive systems. This research extends the architecture-based software reliability prediction model for computer forensic tools, which is based on Markov chains and COSMIC-FFP. Basically, every part of the computer forensic tool is linked to a discrete time Markov chain. If this can be done, then a probabilistic analysis by Markov chains can be performed to analyze the reliability of the components and of the whole tool. The purposes of the proposed reliability assessment method are to evaluate the tool's reliability in the early phases of its development, to improve the reliability assessment process for large computer forensic tools over time, and to compare alternative tool designs. The reliability analysis can assist designers in choosing the most reliable topology for the components, which can maximize the reliability of the tool and meet the expected reliability level specified by the end-user. The approach of assessing component-based tool reliability in the COSMIC-FFP context is illustrated with the Forensic Toolkit Imager case study.

Reliability and Validity of Modified Service Quality Instrument (SERVQUAL) in Patients’ Motivation to Adhere to Insulin Therapy

PubMed Central

Jakupovic, Vedran; Solakovic, Suajb; Celebic, Nedim; Kulovic, Dzenan

2018-01-01

Introduction: Diabetes is progressive condition which requires various ways of treatment. Adequate therapy prescribed in the right time helps patient to postpone development of complications. Adherence to complicated therapy is challenge for both patients and HCPs and is subject of research in many disciplines. Improvement in communication between HCP and patients is very important in patient’s adherence to therapy. Aim: Aim of this research was to explore validity and reliability of modified SERVQUAL instrument in attempt to explore ways of motivating diabetic patient to accept prescribed insulin therapy. Material and Methods: We used modified SERVQUAL questionnaire as instrument in the research. It was necessary to check validity and reliability of the new modified instrument. Results: Results show that modified Servqual instrument has excellent reliability (α=0.908), so we could say that it measures precisely Expectations, Perceptions and Motivation at patients. Factor analysis (EFA method) with Varimax rotation extracted 4 factors which together explain 52.902% variance of the results on this subscale. Bifactorial solution could be seen on Scree-plot diagram (break at second factor). Conclusion: Results in this research show that modified Servqual instrument which is created in order to measure expectations and perceptions of the patients is valid and reliable. Reliability and validity are proven indeed in additional dimension which was created originally for this research - motivation to accept insulin therapy. PMID:29670478

Reliability Methods for Shield Design Process

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Wilson, J. W.

2002-01-01

Providing protection against the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space operations. In this enabling technology, we have developed methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and duty phase of space missions. The total shield mass over all pieces of equipment and habitats is optimized subject to career dose and dose rate constraints. An important component of this technology is the estimation of two most commonly identified uncertainties in radiation shield design, the shielding properties of materials used and the understanding of the biological response of the astronaut to the radiation leaking through the materials into the living space. The largest uncertainty, of course, is in the biological response to especially high charge and energy (HZE) ions of the galactic cosmic rays. These uncertainties are blended with the optimization design procedure to formulate reliability-based methods for shield design processes. The details of the methods will be discussed.

Ricin detection: tracking active toxin.

PubMed

Bozza, William P; Tolleson, William H; Rivera Rosado, Leslie A; Zhang, Baolin

2015-01-01

Ricin is a plant toxin with high bioterrorism potential due to its natural abundance and potency in inducing cell death. Early detection of the active toxin is essential for developing appropriate countermeasures. Here we review concepts for designing ricin detection methods, including mechanism of action of the toxin, advantages and disadvantages of current detection assays, and perspectives on the future development of rapid and reliable methods for detecting ricin in environmental samples. Published by Elsevier Inc.

Development of a refractive error quality of life scale for Thai adults (the REQ-Thai).

PubMed

Sukhawarn, Roongthip; Wiratchai, Nonglak; Tatsanavivat, Pyatat; Pitiyanuwat, Somwung; Kanato, Manop; Srivannaboon, Sabong; Guyatt, Gordon H

2011-08-01

To develop a scale for measuring refractive error quality of life (QOL) for Thai adults. The full survey comprised 424 respondents from 5 medical centers in Bangkok and from 3 medical centers in Chiangmai, Songkla and KhonKaen provinces. Participants were emmetropes and persons with refractive correction with visual acuity of 20/30 or better An item reduction process was employed by combining 3 methods-expert opinion, impact method and item-total correlation methods. The classical reliability testing and the validity testing including convergent, discriminative and construct validity was performed. The developed questionnaire comprised 87 items in 6 dimensions: 1) quality of vision, 2) visual function, 3) social function, 4) psychological function, 5) symptoms and 6) refractive correction problems. It is the 5-level Likert scale type. The Cronbach's Alpha coefficients of its dimensions ranged from 0.756 to 0. 979. All validity testing were shown to be valid. The construct validity was validated by the confirmatory factor analysis. A short version questionnaire comprised 48 items with good reliability and validity was also developed. This is the first validated instrument for measuring refractive error quality of life for Thai adults that was developed with strong research methodology and large sample size.

Structured implicit review: a new method for monitoring nursing care quality.

PubMed

Pearson, M L; Lee, J L; Chang, B L; Elliott, M; Kahn, K L; Rubenstein, L V

2000-11-01

Nurses' independent decisions about assessment, treatment, and nursing interventions for hospitalized patients are important determinants of quality of care. Physician peer implicit review of medical records has been central to Medicare quality management and is considered the gold standard for reviewing physician care, but peer implicit review of nursing processes of care has not received similar attention. The objective of this study was to develop and evaluate nurse structured implicit review (SIR) methods. We developed SIR instruments for rating the quality of inpatient nursing care for congestive heart failure (CHF) and cerebrovascular accident (CVA). Nurse reviewers used the SIR form to rate a nationally representative sample of randomly selected medical records for each disease from 297 acute care hospitals in 5 states (collected by the RAND-HCFA Prospective Payment System study). The study subjects were elderly Medicare inpatients with CHF (n = 291) or CVA (n = 283). We developed and tested scales reflecting domains of nursing process, evaluated interrater and interitem reliability, and assessed the extent to which items and scales predicted overall ratings of the quality of nursing care. Interrater reliability for 14 of 16 scales (CHF) or 10 of 16 scales (CVA) was > or = 0.40. Interitem reliability was > 0.80 for all but 1 scale (both diseases). Functional Assessment, Physical Assessment, and Medication Tracking ratings were the strongest predictors of overall nursing quality ratings (P < 0.001 for each). Nurse peer review with SIR has adequate interrater and excellent scale reliabilities and can be a valuable tool for assessing nurse performance.

Automatic Feature Detection, Description and Matching from Mobile Laser Scanning Data and Aerial Imagery

NASA Astrophysics Data System (ADS)

Hussnain, Zille; Oude Elberink, Sander; Vosselman, George

2016-06-01

In mobile laser scanning systems, the platform's position is measured by GNSS and IMU, which is often not reliable in urban areas. Consequently, derived Mobile Laser Scanning Point Cloud (MLSPC) lacks expected positioning reliability and accuracy. Many of the current solutions are either semi-automatic or unable to achieve pixel level accuracy. We propose an automatic feature extraction method which involves utilizing corresponding aerial images as a reference data set. The proposed method comprise three steps; image feature detection, description and matching between corresponding patches of nadir aerial and MLSPC ortho images. In the data pre-processing step the MLSPC is patch-wise cropped and converted to ortho images. Furthermore, each aerial image patch covering the area of the corresponding MLSPC patch is also cropped from the aerial image. For feature detection, we implemented an adaptive variant of Harris-operator to automatically detect corner feature points on the vertices of road markings. In feature description phase, we used the LATCH binary descriptor, which is robust to data from different sensors. For descriptor matching, we developed an outlier filtering technique, which exploits the arrangements of relative Euclidean-distances and angles between corresponding sets of feature points. We found that the positioning accuracy of the computed correspondence has achieved the pixel level accuracy, where the image resolution is 12cm. Furthermore, the developed approach is reliable when enough road markings are available in the data sets. We conclude that, in urban areas, the developed approach can reliably extract features necessary to improve the MLSPC accuracy to pixel level.

Initial Development and Validation of the BullyHARM: The Bullying, Harassment, and Aggression Receipt Measure.

PubMed

Hall, William J

2016-11-01

This article describes the development and preliminary validation of the Bullying, Harassment, and Aggression Receipt Measure (BullyHARM). The development of the BullyHARM involved a number of steps and methods, including a literature review, expert review, cognitive testing, readability testing, data collection from a large sample, reliability testing, and confirmatory factor analysis. A sample of 275 middle school students was used to examine the psychometric properties and factor structure of the BullyHARM, which consists of 22 items and 6 subscales: physical bullying, verbal bullying, social/relational bullying, cyber-bullying, property bullying, and sexual bullying. First-order and second-order factor models were evaluated. Results demonstrate that the first-order factor model had superior fit. Results of reliability testing indicate that the BullyHARM scale and subscales have very good internal consistency reliability. Findings indicate that the BullyHARM has good properties regarding content validation and respondent-related validation and is a promising instrument for measuring bullying victimization in school.

Initial Development and Validation of the BullyHARM: The Bullying, Harassment, and Aggression Receipt Measure

PubMed Central

Hall, William J.

2017-01-01

This article describes the development and preliminary validation of the Bullying, Harassment, and Aggression Receipt Measure (BullyHARM). The development of the BullyHARM involved a number of steps and methods, including a literature review, expert review, cognitive testing, readability testing, data collection from a large sample, reliability testing, and confirmatory factor analysis. A sample of 275 middle school students was used to examine the psychometric properties and factor structure of the BullyHARM, which consists of 22 items and 6 subscales: physical bullying, verbal bullying, social/relational bullying, cyber-bullying, property bullying, and sexual bullying. First-order and second-order factor models were evaluated. Results demonstrate that the first-order factor model had superior fit. Results of reliability testing indicate that the BullyHARM scale and subscales have very good internal consistency reliability. Findings indicate that the BullyHARM has good properties regarding content validation and respondent-related validation and is a promising instrument for measuring bullying victimization in school. PMID:28194041

Home Lighting Assessment for Clients With Low Vision

PubMed Central

Bhorade, Anjali; Gordon, Mae; Hollingsworth, Holly; Engsberg, Jack E.; Baum, M. Carolyn

2013-01-01

OBJECTIVE. The goal was to develop an objective, comprehensive, near-task home lighting assessment for older adults with low vision. METHOD. A home lighting assessment was developed and tested with older adults with low vision. Interrater and test–retest reliability studies were conducted. Clinical utility was assessed by occupational therapists with expertise in low vision rehabilitation. RESULTS. Interrater reliability was high (intraclass correlation coefficient [ICC] = .83–1.0). Test–retest reliability was moderate (ICC = .67). Responses to a Clinical Utility Feedback Form developed for this study indicated that the Home Environment Lighting Assessment (HELA) has strong clinical utility. CONCLUSION. The HELA provides a structured tool to describe the quantitative and qualitative aspects of home lighting environments where near tasks are performed and can be used to plan lighting interventions. The HELA has the potential to affect assessment and intervention practices of rehabilitation professionals in the area of low vision and improve near-task performance of people with low vision. PMID:24195901

Developing a novel hierarchical approach for multiscale structural reliability predictions for ultra-high consequence applications

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

Emery, John M.; Coffin, Peter; Robbins, Brian A.

Microstructural variabilities are among the predominant sources of uncertainty in structural performance and reliability. We seek to develop efficient algorithms for multiscale calcu- lations for polycrystalline alloys such as aluminum alloy 6061-T6 in environments where ductile fracture is the dominant failure mode. Our approach employs concurrent multiscale methods, but does not focus on their development. They are a necessary but not sufficient ingredient to multiscale reliability predictions. We have focused on how to efficiently use concurrent models for forward propagation because practical applications cannot include fine-scale details throughout the problem domain due to exorbitant computational demand. Our approach begins withmore » a low-fidelity prediction at the engineering scale that is sub- sequently refined with multiscale simulation. The results presented in this report focus on plasticity and damage at the meso-scale, efforts to expedite Monte Carlo simulation with mi- crostructural considerations, modeling aspects regarding geometric representation of grains and second-phase particles, and contrasting algorithms for scale coupling.« less

A review on green synthesis of silver nanoparticles and their applications.

PubMed

Rafique, Muhammad; Sadaf, Iqra; Rafique, M Shahid; Tahir, M Bilal

2017-11-01

Development of reliable and eco-accommodating methods for the synthesis of nanoparticles is a vital step in the field of nanotechnology. Silver nanoparticles are important because of their exceptional chemical, physical, and biological properties, and hence applications. In the last decade, numerous efforts were made to develop green methods of synthesis to avoid the hazardous byproducts. This review describes the methods of green synthesis for Ag-NPs and their numerous applications. It also describes the comparison of efficient synthesis methods via green routes over physical and chemical methods, which provide strong evidence for the selection of suitable method for the synthesis of Ag-NPs.

Skeletal maturation in individuals with Down's syndrome: comparison between PGS curve, cervical vertebrae and bones of the hand and wrist.

PubMed

Carinhena, Glauber; Siqueira, Danilo Furquim; Sannomiya, Eduardo Kazuo

2014-01-01

This study was conducted with the aim of adapting the methods developed by Martins and Sakima to assess skeletal maturation by cervical vertebrae in the pubertal growth spurt (PGS) curve. It also aimed to test the reliability and agreement between those methods and the method of hand and wrist radiograph when compared two by two and all together.  The sample comprised 72 radiographs, with 36 lateral radiographs of the head and 36 hand-wrist radiographs of 36 subjects with Down's syndrome (DS), 13 female and 23 male, aged between 8 years and 6 months and 18 years and 7 months, with an average age of 13 years and 10 months.  Results revealed that adapting the methods developed by Martins and Sakima to assess skeletal maturation by cervical vertebrae in the PGS curve is practical and useful in determining the stage of growth and development of individuals. The stages of maturation evaluated by cervical vertebrae and ossification centers observed in radiographs of the hand and wrist were considered reliable, with excellent level of agreement between the methods by Hassel and Farman as well as Baccetti, Franchi and McNamara Jr and Martins and Sakima. Additionally, results revealed an agreement that ranged between reasonable to good for the three methods used to assess the skeletal maturation, showing statistical significance.

Priority Determination of Underwater Tourism Site Development in Gorontalo Province using Analytical Hierarchy Process (AHP)

NASA Astrophysics Data System (ADS)

Rohandi, M.; Tuloli, M. Y.; Jassin, R. T.

2018-02-01

This research aims to determine the development of priority of underwater tourism in Gorontalo province using the Analytical Hierarchy Process (AHP) method which is one of DSS methods applying Multi-Attribute Decision Making (MADM). This method used 5 criteria and 28 alternatives to determine the best priority of underwater tourism site development in Gorontalo province. Based on the AHP calculation it appeared that the best priority development of underwater tourism site is Pulau Cinta whose total AHP score is 0.489 or 48.9%. This DSS produced a reliable result, faster solution, time-saving, and low cost for the decision makers to obtain the best underwater tourism site to be developed.

Complexity of GPs' explanations about mental health problems: development, reliability, and validity of a measure

PubMed Central

Cape, John; Morris, Elena; Burd, Mary; Buszewicz, Marta

2008-01-01

Background How GPs understand mental health problems determines their treatment choices; however, measures describing GPs' thinking about such problems are not currently available. Aim To develop a measure of the complexity of GP explanations of common mental health problems and to pilot its reliability and validity. Design of study A qualitative development of the measure, followed by inter-rater reliability and validation pilot studies. Setting General practices in North London. Method Vignettes of simulated consultations with patients with mental health problems were videotaped, and an anchored measure of complexity of psychosocial explanation in response to these vignettes was developed. Six GPs, four psychologists, and two lay people viewed the vignettes. Their responses were rated for complexity, both using the anchored measure and independently by two experts in primary care mental health. In a second reliability and revalidation study, responses of 50 GPs to two vignettes were rated for complexity. The GPs also completed a questionnaire to determine their interest and training in mental health, and they completed the Depression Attitudes Questionnaire. Results Inter-rater reliability of the measure of complexity of explanation in both pilot studies was satisfactory (intraclass correlation coefficient = 0.78 and 0.72). The measure correlated with expert opinion as to what constitutes a complex explanation, and the responses of psychologists, GPs, and lay people differed in measured complexity. GPs with higher complexity scores had greater interest, more training in mental health, and more positive attitudes to depression. Conclusion Results suggest that the complexity of GPs' psychosocial explanations about common mental health problems can be reliably and validly assessed by this new standardised measure. PMID:18505616

The Preliminary Results of GMSTech: A Software Development for Microseismic Characterization

NASA Astrophysics Data System (ADS)

Rohaman, Maman; Suhendi, Cahli; Verdhora Ry, Rexha; Sugiartono Prabowo, Billy; Widiyantoro, Sri; Nugraha, Andri Dian; Yudistira, Tedi; Mujihardi, Bambang

2017-04-01

The processing of microseismic data requires reliable software for imaging the condition of subsurface related to occurring microseismicity. In general, the currently available software is only specific for certain processing module and developed by the different developer. However, the software with integrated processing modules will give a better value because the users can use it easier and faster. We developed GMSTech (Ganesha Microseismic Technology), a C# language-based standing-alone software consisting several modules for processing of microseismic data. Its function is to solve a non-linear inverse problem and imaging the subsurface. C# library is supported by ILNumerics to reduce time consumption and give good visualization. In this preliminary result, we will present four developed modules: (1) hypocenter determination, (2) moment magnitude calculation, and (3) 3D seismic tomography. In the first module, we provide four methods for locating the microseismic events that can be chosen by a user independently: simulated annealing method, guided grid-search method, Geiger’s method, and joint hypocenter determination (JHD). The second module can be used for calculating moment magnitude using Brune method and to estimate the released energy of the event. At last, we also provided the module of 3-D seismic tomography for imaging the velocity structures based on delay time tomography. We demonstrated the software using both a synthetic data and a real data from a certain geothermal field in Indonesia. The results for all modules are reliable and remarkable, reviewed statistically by RMS error. We will keep examining the software using another set of data and developing further modules of processing.

Measurement of the distribution of non-structural carbohydrate composition in onion populations by a high-throughput microplate enzymatic assay.

PubMed

Revanna, Roopashree; Turnbull, Matthew H; Shaw, Martin L; Wright, Kathryn M; Butler, Ruth C; Jameson, Paula E; McCallum, John A

2013-08-15

Non-structural carbohydrate (NSC; glucose, fructose, sucrose and fructan) composition of onions (Allium cepa L.) varies widely and is a key determinant of market usage. To analyse the physiology and genetics of onion carbohydrate metabolism and to enable selective breeding, an inexpensive, reliable and practicable sugar assay is required to phenotype large numbers of samples. A rapid, reliable and cost-effective microplate-based assay was developed for NSC analysis in onions and used to characterise variation in tissue hexose, sucrose and fructan content in open-pollinated breeding populations and in mapping populations developed from a wide onion cross. Sucrose measured in microplates employing maltase as a hydrolytic enzyme was in agreement with HPLC-PAD results. The method revealed significant variation in bulb fructan content within open-pollinated 'Pukekohe Longkeeper' breeding populations over a threefold range. Very wide segregation from 80 to 600 g kg(-1) in fructan content was observed in bulbs of F2 genetic mapping populations from the wide onion cross 'Nasik Red × CUDH2150'. The microplate enzymatic assay is a reliable and practicable method for onion sugar analysis for genetics, breeding and food technology. Open-pollinated onion populations may harbour extensive within-population variability in carbohydrate content, which may be quantified and exploited using this method. The phenotypic data obtained from genetic mapping populations show that the method is well suited to detailed genetic and physiological analysis. © 2013 Society of Chemical Industry.

A study on reliability of power customer in distribution network

NASA Astrophysics Data System (ADS)

Liu, Liyuan; Ouyang, Sen; Chen, Danling; Ma, Shaohua; Wang, Xin

2017-05-01

The existing power supply reliability index system is oriented to power system without considering actual electricity availability in customer side. In addition, it is unable to reflect outage or customer’s equipment shutdown caused by instantaneous interruption and power quality problem. This paper thus makes a systematic study on reliability of power customer. By comparing with power supply reliability, reliability of power customer is defined and extracted its evaluation requirements. An indexes system, consisting of seven customer indexes and two contrast indexes, are designed to describe reliability of power customer from continuity and availability. In order to comprehensively and quantitatively evaluate reliability of power customer in distribution networks, reliability evaluation method is proposed based on improved entropy method and the punishment weighting principle. Practical application has proved that reliability index system and evaluation method for power customer is reasonable and effective.

Predicting Software Suitability Using a Bayesian Belief Network

NASA Technical Reports Server (NTRS)

Beaver, Justin M.; Schiavone, Guy A.; Berrios, Joseph S.

2005-01-01

The ability to reliably predict the end quality of software under development presents a significant advantage for a development team. It provides an opportunity to address high risk components earlier in the development life cycle, when their impact is minimized. This research proposes a model that captures the evolution of the quality of a software product, and provides reliable forecasts of the end quality of the software being developed in terms of product suitability. Development team skill, software process maturity, and software problem complexity are hypothesized as driving factors of software product quality. The cause-effect relationships between these factors and the elements of software suitability are modeled using Bayesian Belief Networks, a machine learning method. This research presents a Bayesian Network for software quality, and the techniques used to quantify the factors that influence and represent software quality. The developed model is found to be effective in predicting the end product quality of small-scale software development efforts.

Reliability and validity assessment of gastrointestinal dystemperaments questionnaire: a novel scale in Persian traditional medicine

PubMed Central

Hoseinzadeh, Hamidreza; Taghipour, Ali; Yousefi, Mahdi

2018-01-01

Background Development of a questionnaire based on the resources of Persian traditional medicine seems necessary. One of the problems faced by practitioners of traditional medicine is the different opinions regarding the diagnosis of general temperament or temperament of member. One of the reasons is the lack of validity tools, and it has led to difficulties in training the student of traditional medicine and the treatment of patients. The differences in the detection methods, have given rise to several treatment methods. Objective The present study aimed to develop a questionnaire and standard software for diagnosis of gastrointestinal dystemperaments. Methods The present research is a tool developing study which included 8 stages of developing the items, determining the statements based on items, assessing the face validity, assessing the content validity, assessing the reliability, rating the items, developing a software for calculation of the total score of the questionnaire named GDS v.1.1, and evaluating the concurrent validity using statistical tests including Cronbach’s alpha coefficient, Cohen’s kappa coefficient. Results Based on the results, 112 notes including 62 symptoms were extracted from resources, and 58 items were obtained from in-person interview sessions with a panel of experts. A statement was selected for each item and, after merging a number of statements, a total of 49 statements were finally obtained. By calculating the score of statement impact and determining the content validity, respectively, 6 and 10 other items were removed from the list of statements. Standardized Cronbach’s alpha for this questionnaire was obtained 0.795 and its concurrent validity was equal to 0.8. Conclusion A quantitative tool was developed for diagnosis and examination of gastrointestinal dystemperaments. The developed questionnaire is adequately reliable and valid for this purpose. In addition, the software can be used for clinical diagnosis. PMID:29629060

Accurate secondary structure prediction and fold recognition for circular dichroism spectroscopy

PubMed Central

Micsonai, András; Wien, Frank; Kernya, Linda; Lee, Young-Ho; Goto, Yuji; Réfrégiers, Matthieu; Kardos, József

2015-01-01

Circular dichroism (CD) spectroscopy is a widely used technique for the study of protein structure. Numerous algorithms have been developed for the estimation of the secondary structure composition from the CD spectra. These methods often fail to provide acceptable results on α/β-mixed or β-structure–rich proteins. The problem arises from the spectral diversity of β-structures, which has hitherto been considered as an intrinsic limitation of the technique. The predictions are less reliable for proteins of unusual β-structures such as membrane proteins, protein aggregates, and amyloid fibrils. Here, we show that the parallel/antiparallel orientation and the twisting of the β-sheets account for the observed spectral diversity. We have developed a method called β-structure selection (BeStSel) for the secondary structure estimation that takes into account the twist of β-structures. This method can reliably distinguish parallel and antiparallel β-sheets and accurately estimates the secondary structure for a broad range of proteins. Moreover, the secondary structure components applied by the method are characteristic to the protein fold, and thus the fold can be predicted to the level of topology in the CATH classification from a single CD spectrum. By constructing a web server, we offer a general tool for a quick and reliable structure analysis using conventional CD or synchrotron radiation CD (SRCD) spectroscopy for the protein science research community. The method is especially useful when X-ray or NMR techniques fail. Using BeStSel on data collected by SRCD spectroscopy, we investigated the structure of amyloid fibrils of various disease-related proteins and peptides. PMID:26038575

A stochastic hybrid systems based framework for modeling dependent failure processes

PubMed Central

Fan, Mengfei; Zeng, Zhiguo; Zio, Enrico; Kang, Rui; Chen, Ying

2017-01-01

In this paper, we develop a framework to model and analyze systems that are subject to dependent, competing degradation processes and random shocks. The degradation processes are described by stochastic differential equations, whereas transitions between the system discrete states are triggered by random shocks. The modeling is, then, based on Stochastic Hybrid Systems (SHS), whose state space is comprised of a continuous state determined by stochastic differential equations and a discrete state driven by stochastic transitions and reset maps. A set of differential equations are derived to characterize the conditional moments of the state variables. System reliability and its lower bounds are estimated from these conditional moments, using the First Order Second Moment (FOSM) method and Markov inequality, respectively. The developed framework is applied to model three dependent failure processes from literature and a comparison is made to Monte Carlo simulations. The results demonstrate that the developed framework is able to yield an accurate estimation of reliability with less computational costs compared to traditional Monte Carlo-based methods. PMID:28231313

A stochastic hybrid systems based framework for modeling dependent failure processes.

PubMed

Fan, Mengfei; Zeng, Zhiguo; Zio, Enrico; Kang, Rui; Chen, Ying

2017-01-01

In this paper, we develop a framework to model and analyze systems that are subject to dependent, competing degradation processes and random shocks. The degradation processes are described by stochastic differential equations, whereas transitions between the system discrete states are triggered by random shocks. The modeling is, then, based on Stochastic Hybrid Systems (SHS), whose state space is comprised of a continuous state determined by stochastic differential equations and a discrete state driven by stochastic transitions and reset maps. A set of differential equations are derived to characterize the conditional moments of the state variables. System reliability and its lower bounds are estimated from these conditional moments, using the First Order Second Moment (FOSM) method and Markov inequality, respectively. The developed framework is applied to model three dependent failure processes from literature and a comparison is made to Monte Carlo simulations. The results demonstrate that the developed framework is able to yield an accurate estimation of reliability with less computational costs compared to traditional Monte Carlo-based methods.

Development of a Self-Rated Mixed Methods Skills Assessment: The National Institutes of Health Mixed Methods Research Training Program for the Health Sciences.

PubMed

Guetterman, Timothy C; Creswell, John W; Wittink, Marsha; Barg, Fran K; Castro, Felipe G; Dahlberg, Britt; Watkins, Daphne C; Deutsch, Charles; Gallo, Joseph J

2017-01-01

Demand for training in mixed methods is high, with little research on faculty development or assessment in mixed methods. We describe the development of a self-rated mixed methods skills assessment and provide validity evidence. The instrument taps six research domains: "Research question," "Design/approach," "Sampling," "Data collection," "Analysis," and "Dissemination." Respondents are asked to rate their ability to define or explain concepts of mixed methods under each domain, their ability to apply the concepts to problems, and the extent to which they need to improve. We administered the questionnaire to 145 faculty and students using an internet survey. We analyzed descriptive statistics and performance characteristics of the questionnaire using the Cronbach alpha to assess reliability and an analysis of variance that compared a mixed methods experience index with assessment scores to assess criterion relatedness. Internal consistency reliability was high for the total set of items (0.95) and adequate (≥0.71) for all but one subscale. Consistent with establishing criterion validity, respondents who had more professional experiences with mixed methods (eg, published a mixed methods article) rated themselves as more skilled, which was statistically significant across the research domains. This self-rated mixed methods assessment instrument may be a useful tool to assess skills in mixed methods for training programs. It can be applied widely at the graduate and faculty level. For the learner, assessment may lead to enhanced motivation to learn and training focused on self-identified needs. For faculty, the assessment may improve curriculum and course content planning.

Reliability of Task-Based fMRI for Preoperative Planning: A Test-Retest Study in Brain Tumor Patients and Healthy Controls

PubMed Central

Morrison, Melanie A.; Churchill, Nathan W.; Cusimano, Michael D.; Schweizer, Tom A.; Das, Sunit; Graham, Simon J.

2016-01-01

Background Functional magnetic resonance imaging (fMRI) continues to develop as a clinical tool for patients with brain cancer, offering data that may directly influence surgical decisions. Unfortunately, routine integration of preoperative fMRI has been limited by concerns about reliability. Many pertinent studies have been undertaken involving healthy controls, but work involving brain tumor patients has been limited. To develop fMRI fully as a clinical tool, it will be critical to examine these reliability issues among patients with brain tumors. The present work is the first to extensively characterize differences in activation map quality between brain tumor patients and healthy controls, including the effects of tumor grade and the chosen behavioral testing paradigm on reliability outcomes. Method Test-retest data were collected for a group of low-grade (n = 6) and high-grade glioma (n = 6) patients, and for matched healthy controls (n = 12), who performed motor and language tasks during a single fMRI session. Reliability was characterized by the spatial overlap and displacement of brain activity clusters, BOLD signal stability, and the laterality index. Significance testing was performed to assess differences in reliability between the patients and controls, and low-grade and high-grade patients; as well as between different fMRI testing paradigms. Results There were few significant differences in fMRI reliability measures between patients and controls. Reliability was significantly lower when comparing high-grade tumor patients to controls, or to low-grade tumor patients. The motor task produced more reliable activation patterns than the language tasks, as did the rhyming task in comparison to the phonemic fluency task. Conclusion In low-grade glioma patients, fMRI data are as reliable as healthy control subjects. For high-grade glioma patients, further investigation is required to determine the underlying causes of reduced reliability. To maximize reliability outcomes, testing paradigms should be carefully selected to generate robust activation patterns. PMID:26894279

Behaviour change techniques: the development and evaluation of a taxonomic method for reporting and describing behaviour change interventions (a suite of five studies involving consensus methods, randomised controlled trials and analysis of qualitative data).

PubMed

Michie, Susan; Wood, Caroline E; Johnston, Marie; Abraham, Charles; Francis, Jill J; Hardeman, Wendy

2015-11-01

Meeting global health challenges requires effective behaviour change interventions (BCIs). This depends on advancing the science of behaviour change which, in turn, depends on accurate intervention reporting. Current reporting often lacks detail, preventing accurate replication and implementation. Recent developments have specified intervention content into behaviour change techniques (BCTs) - the 'active ingredients', for example goal-setting, self-monitoring of behaviour. BCTs are 'the smallest components compatible with retaining the postulated active ingredients, i.e. the proposed mechanisms of change. They can be used alone or in combination with other BCTs' (Michie S, Johnston M. Theories and techniques of behaviour change: developing a cumulative science of behaviour change. Health Psychol Rev 2012;6:1-6). Domain-specific taxonomies of BCTs have been developed, for example healthy eating and physical activity, smoking cessation and alcohol consumption. We need to build on these to develop an internationally shared language for specifying and developing interventions. This technology can be used for synthesising evidence, implementing effective interventions and testing theory. It has enormous potential added value for science and global health. (1) To develop a method of specifying content of BCIs in terms of component BCTs; (2) to lay a foundation for a comprehensive methodology applicable to different types of complex interventions; (3) to develop resources to support application of the taxonomy; and (4) to achieve multidisciplinary and international acceptance for future development. Four hundred participants (systematic reviewers, researchers, practitioners, policy-makers) from 12 countries engaged in investigating, designing and/or delivering BCIs. Development of the taxonomy involved a Delphi procedure, an iterative process of revisions and consultation with 41 international experts; hierarchical structure of the list was developed using inductive 'bottom-up' and theory-driven 'top-down' open-sort procedures (n = 36); training in use of the taxonomy (1-day workshops and distance group tutorials) (n = 161) was evaluated by changes in intercoder reliability and validity (agreement with expert consensus); evaluating the taxonomy for coding interventions was assessed by reliability (intercoder; test-retest) and validity (n = 40 trained coders); and evaluating the taxonomy for writing descriptions was assessed by reliability (intercoder; test-retest) and by experimentally testing its value (n = 190). Ninety-three distinct, non-overlapping BCTs with clear labels and definitions formed Behaviour Change Technique Taxonomy version 1 (BCTTv1). BCTs clustered into 16 groupings using a 'bottom-up' open-sort procedure; there was overlap between these and groupings produced by a theory-driven, 'top-down' procedure. Both training methods improved validity (both p < 0.05), doubled the proportion of coders achieving competence and improved confidence in identifying BCTs in workshops (both p < 0.001) but did not improve intercoder reliability. Good intercoder reliability was observed for 80 of the 93 BCTs. Good within-coder agreement was observed after 1 month (p < 0.001). Validity was good for 14 of 15 BCTs in the descriptions. The usefulness of BCTTv1 to report descriptions of observed interventions had mixed results. The developed taxonomy (BCTTv1) provides a methodology for identifying content of complex BCIs and a foundation for international cross-disciplinary collaboration for developing more effective interventions to improve health. Further work is needed to examine its usefulness for reporting interventions. This project was funded by the Medical Research Council Ref: G0901474/1. Funding also came from the Peninsula Collaboration for Leadership in Applied Health Research and Care.

Two-dimensional digital photography for child body posture evaluation: standardized technique, reliable parameters and normative data for age 7-10 years.

PubMed

Stolinski, L; Kozinoga, M; Czaprowski, D; Tyrakowski, M; Cerny, P; Suzuki, N; Kotwicki, T

2017-01-01

Digital photogrammetry provides measurements of body angles or distances which allow for quantitative posture assessment with or without the use of external markers. It is becoming an increasingly popular tool for the assessment of the musculoskeletal system. The aim of this paper is to present a structured method for the analysis of posture and its changes using a standardized digital photography technique. The purpose of the study was twofold. The first one comprised 91 children (44 girls and 47 boys) aged 7-10 (8.2 ± 1.0), i.e., students of primary school, and its aim was to develop the photographic method, choose the quantitative parameters, and determine the intraobserver reliability (repeatability) along with the interobserver reliability (reproducibility) measurements in sagittal plane using digital photography, as well as to compare the Rippstein plurimeter and digital photography measurements. The second one involved 7782 children (3804 girls, 3978 boys) aged 7-10 (8.4 ± 0.5), who underwent digital photography postural screening. The methods consisted in measuring and calculating selected parameters, establishing the normal ranges of photographic parameters, presenting percentile charts, as well as noticing common pitfalls and possible sources of errors in digital photography. A standardized procedure for the photographic evaluation of child body posture was presented. The photographic measurements revealed very good intra- and inter-rater reliability regarding the five sagittal parameters and good reliability performed against Rippstein plurimeter measurements. The parameters displayed insignificant variability over time. Normative data were calculated based on photographic assessment, while the percentile charts were provided to serve as reference values. The technical errors observed during photogrammetry are carefully discussed in this article. Technical developments are allowed for the regular use of digital photogrammetry in body posture assessment. Specific child positioning (described above) enables us to avoid incidentally modified posture. Image registration is simple, quick, harmless, and cost-effective. The semi-automatic image analysis, together with the normal values and percentile charts, makes the technique reliable in terms of child's posture documentation and corrective therapy effects' monitoring.

The Development of a Motor-Free Short-Form of the Wechsler Intelligence Scale for Children-Fifth Edition.

PubMed

Piovesana, Adina M; Harrison, Jessica L; Ducat, Jacob J

2017-12-01

This study aimed to develop a motor-free short-form of the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V) that allows clinicians to estimate the Full Scale Intelligence Quotients of youths with motor impairments. Using the reliabilities and intercorrelations of six WISC-V motor-free subtests, psychometric methodologies were applied to develop look-up tables for four Motor-free Short-form indices: Verbal Comprehension Short-form, Perceptual Reasoning Short-form, Working Memory Short-form, and a Motor-free Intelligence Quotient. Index-level discrepancy tables were developed using the same methods to allow clinicians to statistically compare visual, verbal, and working memory abilities. The short-form indices had excellent reliabilities ( r = .92-.97) comparable to the original WISC-V. This motor-free short-form of the WISC-V is a reliable alternative for the assessment of intellectual functioning in youths with motor impairments. Clinicians are provided with user-friendly look-up tables, index level discrepancy tables, and base rates, displayed similar to those in the WISC-V manuals to enable interpretation of assessment results.

"Not just little adults": qualitative methods to support the development of pediatric patient-reported outcomes.

PubMed

Arbuckle, Rob; Abetz-Webb, Linda

2013-01-01

The US FDA and the European Medicines Agency (EMA) have issued incentives and laws mandating clinical research in pediatrics. While guidances for the development and validation of patient-reported outcomes (PROs) or health-related quality of life (HRQL) measures have been issued by these agencies, little attention has focused on pediatric PRO development methods. With reference to the literature, this article provides an overview of specific considerations that should be made with regard to the development of pediatric PRO measures, with a focus on performing qualitative research to ensure content validity. Throughout the questionnaire development process it is critical to use developmentally appropriate language and techniques to ensure outcomes have content validity, and will be reliable and valid within narrow age bands (0-2, 3-5, 6-8, 9-11, 12-14, 15-17 years). For qualitative research, sample sizes within those age bands must be adequate to demonstrate saturation while taking into account children's rapid growth and development. Interview methods, interview guides, and length of interview must all take developmental stage into account. Drawings, play-doh, or props can be used to engage the child. Care needs to be taken during cognitive debriefing, where repeated questioning can lead a child to change their answers, due to thinking their answer is incorrect. For the PROs themselves, the greatest challenge is in measuring outcomes in children aged 5-8 years. In this age range, while self-report is generally more valid, parent reports of observable behaviors are generally more reliable. As such, 'team completion' or a parent-administered child report is often the best option for children aged 5-8 years. For infants and very young children (aged 0-4 years), patient rating of observable behaviors is necessary, and, for adolescents and children aged 9 years and older, self-reported outcomes are generally valid and reliable. In conclusion, the development of PRO measures for use in children requires careful tailoring of qualitative methods, and performing research within narrow age bands. The best reporter should be carefully considered dependent on the child's age, developmental ability, and the concept being measured, and team completion should be considered alongside self-completion and observer measures.

Identifying Dyslexia in Adults: An Iterative Method Using the Predictive Value of Item Scores and Self-Report Questions

ERIC Educational Resources Information Center

Tamboer, Peter; Vorst, Harrie C. M.; Oort, Frans J.

2014-01-01

Methods for identifying dyslexia in adults vary widely between studies. Researchers have to decide how many tests to use, which tests are considered to be the most reliable, and how to determine cut-off scores. The aim of this study was to develop an objective and powerful method for diagnosing dyslexia. We took various methodological measures,…

Bayesian methods in reliability

NASA Astrophysics Data System (ADS)

Sander, P.; Badoux, R.

1991-11-01

The present proceedings from a course on Bayesian methods in reliability encompasses Bayesian statistical methods and their computational implementation, models for analyzing censored data from nonrepairable systems, the traits of repairable systems and growth models, the use of expert judgment, and a review of the problem of forecasting software reliability. Specific issues addressed include the use of Bayesian methods to estimate the leak rate of a gas pipeline, approximate analyses under great prior uncertainty, reliability estimation techniques, and a nonhomogeneous Poisson process. Also addressed are the calibration sets and seed variables of expert judgment systems for risk assessment, experimental illustrations of the use of expert judgment for reliability testing, and analyses of the predictive quality of software-reliability growth models such as the Weibull order statistics.

Methods for Quantification of Soil-Transmitted Helminths in Environmental Media: Current Techniques and Recent Advances.

PubMed

Collender, Philip A; Kirby, Amy E; Addiss, David G; Freeman, Matthew C; Remais, Justin V

2015-12-01

Limiting the environmental transmission of soil-transmitted helminths (STHs), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost-effective methods to detect and quantify STHs in the environment. We review the state-of-the-art of STH quantification in soil, biosolids, water, produce, and vegetation with regard to four major methodological issues: environmental sampling; recovery of STHs from environmental matrices; quantification of recovered STHs; and viability assessment of STH ova. We conclude that methods for sampling and recovering STHs require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

FAA center for aviation systems reliability: an overview

NASA Astrophysics Data System (ADS)

Brasche, Lisa J. H.

1996-11-01

The FAA Center for Aviation Systems Reliability has as its objectives: to develop quantitative nondestructive evaluation (NDE) methods for aircraft structures and materials, including prototype instrumentation, software, techniques and procedures; and to develop and maintain comprehensive education and training programs specific to the inspection of aviation structures. The program, which includes contributions from Iowa State University, Northwestern University, Wayne State University, Tuskegee University, AlliedSignal Propulsion Engines, General Electric Aircraft Engines and Pratt and Whitney, has been in existence since 1990. Efforts under way include: development of inspection for adhesively bonded structures; detection of corrosion; development of advanced NDE concepts that form the basis for an inspection simulator; improvements of titanium inspection as part of the Engine Titanium Consortium; development of education and training program. An overview of the efforts underway will be provided with focus on those technologies closest to technology transfer.

Structural reliability calculation method based on the dual neural network and direct integration method.

PubMed

Li, Haibin; He, Yun; Nie, Xiaobo

2018-01-01

Structural reliability analysis under uncertainty is paid wide attention by engineers and scholars due to reflecting the structural characteristics and the bearing actual situation. The direct integration method, started from the definition of reliability theory, is easy to be understood, but there are still mathematics difficulties in the calculation of multiple integrals. Therefore, a dual neural network method is proposed for calculating multiple integrals in this paper. Dual neural network consists of two neural networks. The neural network A is used to learn the integrand function, and the neural network B is used to simulate the original function. According to the derivative relationships between the network output and the network input, the neural network B is derived from the neural network A. On this basis, the performance function of normalization is employed in the proposed method to overcome the difficulty of multiple integrations and to improve the accuracy for reliability calculations. The comparisons between the proposed method and Monte Carlo simulation method, Hasofer-Lind method, the mean value first-order second moment method have demonstrated that the proposed method is an efficient and accurate reliability method for structural reliability problems.

Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus

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

Bielecki, J.; Scholz, M.; Drozdowicz, K.

A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape ofmore » normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutron emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.« less

Recent Developments and Applications of the MMPBSA Method

PubMed Central

Wang, Changhao; Greene, D'Artagnan; Xiao, Li; Qi, Ruxi; Luo, Ray

2018-01-01

The Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) approach has been widely applied as an efficient and reliable free energy simulation method to model molecular recognition, such as for protein-ligand binding interactions. In this review, we focus on recent developments and applications of the MMPBSA method. The methodology review covers solvation terms, the entropy term, extensions to membrane proteins and high-speed screening, and new automation toolkits. Recent applications in various important biomedical and chemical fields are also reviewed. We conclude with a few future directions aimed at making MMPBSA a more robust and efficient method. PMID:29367919

System Design under Uncertainty: Evolutionary Optimization of the Gravity Probe-B Spacecraft

NASA Technical Reports Server (NTRS)

Pullen, Samuel P.; Parkinson, Bradford W.

1994-01-01

This paper discusses the application of evolutionary random-search algorithms (Simulated Annealing and Genetic Algorithms) to the problem of spacecraft design under performance uncertainty. Traditionally, spacecraft performance uncertainty has been measured by reliability. Published algorithms for reliability optimization are seldom used in practice because they oversimplify reality. The algorithm developed here uses random-search optimization to allow us to model the problem more realistically. Monte Carlo simulations are used to evaluate the objective function for each trial design solution. These methods have been applied to the Gravity Probe-B (GP-B) spacecraft being developed at Stanford University for launch in 1999, Results of the algorithm developed here for GP-13 are shown, and their implications for design optimization by evolutionary algorithms are discussed.

Developing a Vocational Index for Adults with Autism Spectrum Disorders

PubMed Central

Seltzer, Marsha Mailick

2012-01-01

Existing methods of indexing the vocational activities of adults with autism spectrum disorders (ASD) have made significant contributions to research. Nonetheless, they are limited by problems with sensitivity and reliability. We developed an index of vocational and educational outcomes that captures the full range of activities experienced by adults with ASD, and that can be reliably coded across studies using specific decision rules. To develop this index, we used employment, vocational, and educational data collected from nearly 350 adults with ASD at 6 times over 12 years, as part of a larger longitudinal study. The resulting index consists of 11 categories coded on a 9-point scale, ranging from competitive employment and/or postsecondary educational program to no vocational/educational activities. PMID:22466690

Development and application of basis database for materials life cycle assessment in china

NASA Astrophysics Data System (ADS)

Li, Xiaoqing; Gong, Xianzheng; Liu, Yu

2017-03-01

As the data intensive method, high quality environmental burden data is an important premise of carrying out materials life cycle assessment (MLCA), and the reliability of data directly influences the reliability of the assessment results and its application performance. Therefore, building Chinese MLCA database is the basic data needs and technical supports for carrying out and improving LCA practice. Firstly, some new progress on database which related to materials life cycle assessment research and development are introduced. Secondly, according to requirement of ISO 14040 series standards, the database framework and main datasets of the materials life cycle assessment are studied. Thirdly, MLCA data platform based on big data is developed. Finally, the future research works were proposed and discussed.

Study on evaluation of construction reliability for engineering project based on fuzzy language operator

NASA Astrophysics Data System (ADS)

Shi, Yu-Fang; Ma, Yi-Yi; Song, Ping-Ping

2018-03-01

System Reliability Theory is a research hotspot of management science and system engineering in recent years, and construction reliability is useful for quantitative evaluation of project management level. According to reliability theory and target system of engineering project management, the defination of construction reliability appears. Based on fuzzy mathematics theory and language operator, value space of construction reliability is divided into seven fuzzy subsets and correspondingly, seven membership function and fuzzy evaluation intervals are got with the operation of language operator, which provides the basis of corresponding method and parameter for the evaluation of construction reliability. This method is proved to be scientific and reasonable for construction condition and an useful attempt for theory and method research of engineering project system reliability.

Development and reliability of a Motivational Interviewing Scenarios Tool for Eating Disorders (MIST-ED) using a skills-based intervention among caregivers.

PubMed

Sepulveda, Ana R; Wise, Caroline; Zabala, Maria; Todd, Gill; Treasure, Janet

2013-12-01

The aims of this study were to develop an eating disorder scenarios tool to assess the motivational interviewing (MI) skills of caregivers and evaluate the coding reliability of the instrument, and to test the sensitivity to change through a pre/post/follow-up design. The resulting Motivational Interview Scenarios Tool for Eating Disorders (MIST-ED) was administered to caregivers (n = 66) who were asked to provide oral and written responses before and after a skills-based intervention, and at a 3-month follow-up. Raters achieved excellent inter-rater reliability (intra-class correlations of 91.8% on MI adherent and 86.1% for MI non-adherent statements for written scenarios and 89.2%, and 85.3% for oral scenarios). Following the intervention, MI adherent statements increased (baseline = 9.4%, post = 61.5% and follow-up 47.2%) and non-MI adherent statements decreased (baseline = 90.6%, post = 38.5% and follow-up = 52.8%). This instrument can be used as a simple method to measure the acquisition of MI skills to improve coping and both response methods are adequate. The tool shows good sensitivity to improved skills. © 2013.

Fast and Reliable Thermodynamic Approach for Determining the Protonation State of the Asp Dyad.

PubMed

Huang, Jinfeng; Sun, Bin; Yao, Yuan; Liu, Junjun

2017-09-25

The protonation state of the asp dyad is significantly important in revealing enzymatic mechanisms and developing drugs. However, it is hard to determine by calculating free energy changes between possible protonation states, because the free energy changes due to protein conformational flexibility are usually much larger than those originating from different locations of protons. Sophisticated and computationally expensive methods such as free energy perturbation, thermodynamic integration (TI), and quantum mechanics/molecular mechanics are therefore usually used for this purpose. In the present study, we have developed a simple thermodynamic approach to effectively eliminating the free energy changes arising from protein conformational flexibility and estimating the free energy changes only originated from the locations of protons, which provides a fast and reliable method for determining the protonation state of asp dyads. The test of this approach on a total of 15 asp dyad systems, including BACE-1 and HIV-1 protease, shows that the predictions from this approach are all consistent with experiments or with the computationally expensive TI calculations. It is clear that our thermodynamic approach could be used to rapidly and reliably determine the protonation state of the asp dyad.

Precise time dissemination and applications development on the Bonneville Power Administration system

NASA Technical Reports Server (NTRS)

Martin, Ken E.; Esztergalyos, J.

1992-01-01

The Bonneville Power Administration (BPA) uses IRIG-B transmitted over microwave as its primary system time dissemination. Problems with accuracy and reliability have led to ongoing research into better methods. BPA has also developed and deployed a unique fault locator which uses precise clocks synchronized by a pulse over microwaves. It automatically transmits the data to a central computer for analysis. A proposed system could combine fault location timing and time dissemination into a Global Position System (GPS) timing receiver and close the verification loop through a master station at the Dittmer Control Center. Such a system would have many advantages, including lower cost, higher reliability, and wider industry support. Test results indicate the GPS has sufficient accuracy and reliability for this and other current timing requirements including synchronous phase angle measurements. A phasor measurement system which provides phase angle has recently been tested with excellent results. Phase angle is a key parameter in power system control applications including dynamic braking, DC modulation, remedial action schemes, and system state estimation. Further research is required to determine the applications which can most effectively use real-time phase angle measurements and the best method to apply them.

Precise time dissemination and applications development on the Bonneville Power Administration system

NASA Astrophysics Data System (ADS)

Martin, Ken E.; Esztergalyos, J.

1992-07-01

The Bonneville Power Administration (BPA) uses IRIG-B transmitted over microwave as its primary system time dissemination. Problems with accuracy and reliability have led to ongoing research into better methods. BPA has also developed and deployed a unique fault locator which uses precise clocks synchronized by a pulse over microwaves. It automatically transmits the data to a central computer for analysis. A proposed system could combine fault location timing and time dissemination into a Global Position System (GPS) timing receiver and close the verification loop through a master station at the Dittmer Control Center. Such a system would have many advantages, including lower cost, higher reliability, and wider industry support. Test results indicate the GPS has sufficient accuracy and reliability for this and other current timing requirements including synchronous phase angle measurements. A phasor measurement system which provides phase angle has recently been tested with excellent results. Phase angle is a key parameter in power system control applications including dynamic braking, DC modulation, remedial action schemes, and system state estimation. Further research is required to determine the applications which can most effectively use real-time phase angle measurements and the best method to apply them.

Expediting topology data gathering for the TOPDB database.

PubMed

Dobson, László; Langó, Tamás; Reményi, István; Tusnády, Gábor E

2015-01-01

The Topology Data Bank of Transmembrane Proteins (TOPDB, http://topdb.enzim.ttk.mta.hu) contains experimentally determined topology data of transmembrane proteins. Recently, we have updated TOPDB from several sources and utilized a newly developed topology prediction algorithm to determine the most reliable topology using the results of experiments as constraints. In addition to collecting the experimentally determined topology data published in the last couple of years, we gathered topographies defined by the TMDET algorithm using 3D structures from the PDBTM. Results of global topology analysis of various organisms as well as topology data generated by high throughput techniques, like the sequential positions of N- or O-glycosylations were incorporated into the TOPDB database. Moreover, a new algorithm was developed to integrate scattered topology data from various publicly available databases and a new method was introduced to measure the reliability of predicted topologies. We show that reliability values highly correlate with the per protein topology accuracy of the utilized prediction method. Altogether, more than 52,000 new topology data and more than 2600 new transmembrane proteins have been collected since the last public release of the TOPDB database. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Developmental monitoring using caregiver reports in a resource-limited setting: the case of Kilifi, Kenya

PubMed Central

Abubakar, A; Holding, P; Van de Vijver, F; Bomu, G; Van Baar, A

2010-01-01

Aim: The main aim of the current study was to evaluate the reliability, validity and acceptability of developmental monitoring using caregiver reports among mothers in a rural African setting. Methods: A structured interview for parents of children aged 24 months and less was developed through both participant consultation and a review of literature. The reliability and validity of the schedule was evaluated through a 10-month monitoring programme of 95 children, aged 2–10 months. The acceptability of the process was evaluated by studying retention rates and by organizing focus group discussions with participating mothers. Results: The structured interview ‘Developmental Milestones Checklist’ consisted of 66 items covering three broad domains of child functioning: motor, language and personal–social development. The interview yielded scores of developmental achievements that showed high internal consistency and excellent test–retest reliability. The results were sensitive to maturational changes and nutritional deficiencies. In addition, acceptable retention rates of approximately 80% were found. Participating mothers reported that they found the procedures both acceptable and beneficial. Conclusion: Developmental monitoring using caregiver report is a viable method to identify and monitor at-risk children in Sub-Saharan Africa. PMID:20353499

Elliptical broken line method for calculating capillary density in nailfold capillaroscopy: Proposal and evaluation.

PubMed

Karbalaie, Abdolamir; Abtahi, Farhad; Fatemi, Alimohammad; Etehadtavakol, Mahnaz; Emrani, Zahra; Erlandsson, Björn-Erik

2017-09-01

Nailfold capillaroscopy is a practical method for identifying and obtaining morphological changes in capillaries which might reveal relevant information about diseases and health. Capillaroscopy is harmless, and seems simple and repeatable. However, there is lack of established guidelines and instructions for acquisition as well as the interpretation of the obtained images; which might lead to various ambiguities. In addition, assessment and interpretation of the acquired images are very subjective. In an attempt to overcome some of these problems, in this study a new modified technique for assessment of nailfold capillary density is introduced. The new method is named elliptic broken line (EBL) which is an extension of the two previously known methods by defining clear criteria for finding the apex of capillaries in different scenarios by using a fitted elliptic. A graphical user interface (GUI) is developed for pre-processing, manual assessment of capillary apexes and automatic correction of selected apexes based on 90° rule. Intra- and inter-observer reliability of EBL and corrected EBL is evaluated in this study. Four independent observers familiar with capillaroscopy performed the assessment for 200 nailfold videocapillaroscopy images, form healthy subject and systemic lupus erythematosus patients, in two different sessions. The results show elevation from moderate (ICC=0.691) and good (ICC=0.753) agreements to good (ICC=0.750) and good (ICC=0.801) for intra- and inter-observer reliability after automatic correction of EBL. This clearly shows the potential of this method to improve the reliability and repeatability of assessment which motivates us for further development of automatic tool for EBL method. Copyright © 2017 Elsevier Inc. All rights reserved.

Differential Weighting for Subcomponent Measures of Integrated Clinical Encounter Scores Based on the USMLE Step 2 CS Examination: Effects on Composite Score Reliability and Pass-Fail Decisions.

PubMed

Park, Yoon Soo; Lineberry, Matthew; Hyderi, Abbas; Bordage, Georges; Xing, Kuan; Yudkowsky, Rachel

2016-11-01

Medical schools administer locally developed graduation competency examinations (GCEs) following the structure of the United States Medical Licensing Examination Step 2 Clinical Skills that combine standardized patient (SP)-based physical examination and the patient note (PN) to create integrated clinical encounter (ICE) scores. This study examines how different subcomponent scoring weights in a locally developed GCE affect composite score reliability and pass-fail decisions for ICE scores, contributing to internal structure and consequential validity evidence. Data from two M4 cohorts (2014: n = 177; 2015: n = 182) were used. The reliability of SP encounter (history taking and physical examination), PN, and communication and interpersonal skills scores were estimated with generalizability studies. Composite score reliability was estimated for varying weight combinations. Faculty were surveyed for preferred weights on the SP encounter and PN scores. Composite scores based on Kane's method were compared with weighted mean scores. Faculty suggested weighting PNs higher (60%-70%) than the SP encounter scores (30%-40%). Statistically, composite score reliability was maximized when PN scores were weighted at 40% to 50%. Composite score reliability of ICE scores increased by up to 0.20 points when SP-history taking (SP-Hx) scores were included; excluding SP-Hx only increased composite score reliability by 0.09 points. Classification accuracy for pass-fail decisions between composite and weighted mean scores was 0.77; misclassification was < 5%. Medical schools and certification agencies should consider implications of assigning weights with respect to composite score reliability and consequences on pass-fail decisions.

Temporal Correlations and Neural Spike Train Entropy

NASA Astrophysics Data System (ADS)

Schultz, Simon R.; Panzeri, Stefano

2001-06-01

Sampling considerations limit the experimental conditions under which information theoretic analyses of neurophysiological data yield reliable results. We develop a procedure for computing the full temporal entropy and information of ensembles of neural spike trains, which performs reliably for limited samples of data. This approach also yields insight to the role of correlations between spikes in temporal coding mechanisms. The method, when applied to recordings from complex cells of the monkey primary visual cortex, results in lower rms error information estimates in comparison to a ``brute force'' approach.

Polish Adult Reading Test (PART) - construction of Polish test for estimating the level of premorbid intelligence in schizophrenia.

PubMed

Karakuła-Juchnowicz, Hanna; Stecka, Mariola

2017-08-29

In view of unavailability in Poland of the standardized methods to measure PIQ, the aim of the work was to develop a Polish test to assess the premorbid level of intelligence - PART(Polish AdultReading Test) and to measureits psychometric properties, such as validity, reliability as well as standardization in the group of schizophrenia patients. The principles of PART construction were based on the idea of popular worldwide National Adult Reading Test by Hazel Nelson. The research comprised a group of 122 subjects (65 schizophrenia patients and 57 healthy people), aged 18-60 years, matched for age and gender. PART appears to be a method with high internal consistency and reliability measured by test-retest, inter-rater reliability, and the method with acceptable diagnostic and prognostic validity. The standardized procedures of PART have been investigated and described. Considering the psychometric values of PART and a short time of its performance, the test may be a useful diagnostic instrument in the assessment of premorbid level of intelligence in a group of schizophrenic patients.

The Role of Probabilistic Design Analysis Methods in Safety and Affordability

NASA Technical Reports Server (NTRS)

Safie, Fayssal M.

2016-01-01

For the last several years, NASA and its contractors have been working together to build space launch systems to commercialize space. Developing commercial affordable and safe launch systems becomes very important and requires a paradigm shift. This paradigm shift enforces the need for an integrated systems engineering environment where cost, safety, reliability, and performance need to be considered to optimize the launch system design. In such an environment, rule based and deterministic engineering design practices alone may not be sufficient to optimize margins and fault tolerance to reduce cost. As a result, introduction of Probabilistic Design Analysis (PDA) methods to support the current deterministic engineering design practices becomes a necessity to reduce cost without compromising reliability and safety. This paper discusses the importance of PDA methods in NASA's new commercial environment, their applications, and the key role they can play in designing reliable, safe, and affordable launch systems. More specifically, this paper discusses: 1) The involvement of NASA in PDA 2) Why PDA is needed 3) A PDA model structure 4) A PDA example application 5) PDA link to safety and affordability.

Extracting More Information from Passive Optical Tracking Observations for Reliable Orbit Element Generation

NASA Astrophysics Data System (ADS)

Bennett, J.; Gehly, S.

2016-09-01

This paper presents results from a preliminary method for extracting more orbital information from low rate passive optical tracking data. An improvement in the accuracy of the observation data yields more accurate and reliable orbital elements. A comparison between the orbit propagations from the orbital element generated using the new data processing method is compared with the one generated from the raw observation data for several objects. Optical tracking data collected by EOS Space Systems, located on Mount Stromlo, Australia, is fitted to provide a new orbital element. The element accuracy is determined from a comparison between the predicted orbit and subsequent tracking data or reference orbit if available. The new method is shown to result in a better orbit prediction which has important implications in conjunction assessments and the Space Environment Research Centre space object catalogue. The focus is on obtaining reliable orbital solutions from sparse data. This work forms part of the collaborative effort of the Space Environment Management Cooperative Research Centre which is developing new technologies and strategies to preserve the space environment (www.serc.org.au).

Development and Standardization of an Alienation Scale for Visually Impaired Students

ERIC Educational Resources Information Center

Punia, Poonam; Berwal, Sandeep

2017-01-01

Introduction: The present study was undertaken to develop a valid and reliable scale for measuring a feeling of alienation in students with visual impairments (that is, those who are blind or have low vision). Methods: In this study, a pool of 60 items was generated to develop an Alienation Scale for Visually Impaired Students (AL-VI) based on a…

Evaluation of Different Scoring Rules for a Noncognitive Test in Development. Research Report. ETS RR-16-03

ERIC Educational Resources Information Center

Guo, Hongwen; Zu, Jiyun; Kyllonen, Patrick; Schmitt, Neal

2016-01-01

In this report, systematic applications of statistical and psychometric methods are used to develop and evaluate scoring rules in terms of test reliability. Data collected from a situational judgment test are used to facilitate the comparison. For a well-developed item with appropriate keys (i.e., the correct answers), agreement among various…

Usefulness and Reliability of Tanner Pubertal Self-Rating to Urban Black Adolescents in South Africa

ERIC Educational Resources Information Center

Norris, Shane A.; Richter, Linda M.

2005-01-01

Self-rating of pubertal development is the recommended method to assess puberty in large community-based surveys of adolescent development and behavior. The aim of this study was to validate for the first time pubertal self-assessment using the sexual maturation scale developed by Tanner among Black South African adolescents (n=182) aged between…

Reliability of pubertal maturation self-assessment in a school-based survey.

PubMed

Jaruratanasirikul, Somchit; Kreetapirom, Piyawut; Tassanakijpanich, Nattaporn; Sriplung, Hutcha

2015-03-01

To assess the reliability of pubertal self-assessment of Thai adolescents. Some 927 girls and 997 boys, aged 8-18 years, from nine schools in Hat-Yai municipality. The adolescents evaluated their pubertal status after being shown a line drawing of the five Tanner stages with a short description. Girls assessed their breast and pubic hair development, and boys assessed their pubic hair development. The pubertal self-assessments were compared to pubertal assessments made by a pediatrician who examined the children after their self-assessment. Kappa coefficient and percent agreement were used for statistical analysis. The percent agreement of breast and pubic hair development between the girl's self-assessments and the assessments by the pediatrician were 60.8% and 78%, respectively. Kappa coefficient for breast assessment was 0.50 (95% confidence interval, CI 0.47-0.53) and for pubic hair 0.68 (95% CI 0.65-0.72). Nearly 30% of girls aged younger than 10 years overestimated their breast development status while 45% of girls aged over 14 years underestimated their breast development (p<0.001). For boys, the percent agreement of pubic hair development between the adolescents and the pediatrician was 76.4%, with a weighted kappa coefficient of 0.68 (95% CI 0.65-0.72). Pubertal self-assessment using line drawings with a short description can be used as a reliable method to assess pubic hair maturation in boys and girls, but can be used with less reliability to assess the breast maturation in young girls.

Body Fat Measurement: Weighing the Pros and Cons of Electrical Impedance.

ERIC Educational Resources Information Center

Nash, Heyward L.

1985-01-01

Research technologists have developed electrical impedance units in response to demand for a convenient and reliable method of measuring body fat. Accuracy of impedance measures versus calipers and underwater weighing are discussed. (MT)

Design, processing and testing of LSI arrays hybrid microelectronics task

NASA Technical Reports Server (NTRS)

Himmel, R. P.; Stuhlbarg, S. M.; Salmassy, S.

1978-01-01

Those factors affecting the cost of electronic subsystems utilizing LSI microcircuits were determined and the most efficient methods for low cost packaging of LSI devices as a function of density and reliability were developed.

Developing safety performance functions incorporating reliability-based risk measures.

PubMed

Ibrahim, Shewkar El-Bassiouni; Sayed, Tarek

2011-11-01

Current geometric design guides provide deterministic standards where the safety margin of the design output is generally unknown and there is little knowledge of the safety implications of deviating from these standards. Several studies have advocated probabilistic geometric design where reliability analysis can be used to account for the uncertainty in the design parameters and to provide a risk measure of the implication of deviation from design standards. However, there is currently no link between measures of design reliability and the quantification of safety using collision frequency. The analysis presented in this paper attempts to bridge this gap by incorporating a reliability-based quantitative risk measure such as the probability of non-compliance (P(nc)) in safety performance functions (SPFs). Establishing this link will allow admitting reliability-based design into traditional benefit-cost analysis and should lead to a wider application of the reliability technique in road design. The present application is concerned with the design of horizontal curves, where the limit state function is defined in terms of the available (supply) and stopping (demand) sight distances. A comprehensive collision and geometric design database of two-lane rural highways is used to investigate the effect of the probability of non-compliance on safety. The reliability analysis was carried out using the First Order Reliability Method (FORM). Two Negative Binomial (NB) SPFs were developed to compare models with and without the reliability-based risk measures. It was found that models incorporating the P(nc) provided a better fit to the data set than the traditional (without risk) NB SPFs for total, injury and fatality (I+F) and property damage only (PDO) collisions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Gauging the gaps in student problem-solving skills: assessment of individual and group use of problem-solving strategies using online discussions.

PubMed

Anderson, William L; Mitchell, Steven M; Osgood, Marcy P

2008-01-01

For the past 3 yr, faculty at the University of New Mexico, Department of Biochemistry and Molecular Biology have been using interactive online Problem-Based Learning (PBL) case discussions in our large-enrollment classes. We have developed an illustrative tracking method to monitor student use of problem-solving strategies to provide targeted help to groups and to individual students. This method of assessing performance has a high interrater reliability, and senior students, with training, can serve as reliable graders. We have been able to measure improvements in many students' problem-solving strategies, but, not unexpectedly, there is a population of students who consistently apply the same failing strategy when there is no faculty intervention. This new methodology provides an effective tool to direct faculty to constructively intercede in this area of student development.

Diagnostic emulation: Implementation and user's guide

NASA Technical Reports Server (NTRS)

Becher, Bernice

1987-01-01

The Diagnostic Emulation Technique was developed within the System Validation Methods Branch as a part of the development of methods for the analysis of the reliability of highly reliable, fault tolerant digital avionics systems. This is a general technique which allows for the emulation of a digital hardware system. The technique is general in the sense that it is completely independent of the particular target hardware which is being emulated. Parts of the system are described and emulated at the logic or gate level, while other parts of the system are described and emulated at the functional level. This algorithm allows for the insertion of faults into the system, and for the observation of the response of the system to these faults. This allows for controlled and accelerated testing of system reaction to hardware failures in the target machine. This document describes in detail how the algorithm was implemented at NASA Langley Research Center and gives instructions for using the system.

Expert system verification and validation study. Delivery 3A and 3B: Trip summaries

NASA Technical Reports Server (NTRS)

French, Scott

1991-01-01

Key results are documented from attending the 4th workshop on verification, validation, and testing. The most interesting part of the workshop was when representatives from the U.S., Japan, and Europe presented surveys of VV&T within their respective regions. Another interesting part focused on current efforts to define industry standards for artificial intelligence and how that might affect approaches to VV&T of expert systems. The next part of the workshop focused on VV&T methods of applying mathematical techniques to verification of rule bases and techniques for capturing information relating to the process of developing software. The final part focused on software tools. A summary is also presented of the EPRI conference on 'Methodologies, Tools, and Standards for Cost Effective Reliable Software Verification and Validation. The conference was divided into discussion sessions on the following issues: development process, automated tools, software reliability, methods, standards, and cost/benefit considerations.