Reliability Demonstration Research Articles

The Psychometric Properties of the Outcome Rating Scale Used in Practice: A Narrative Review

ABSTRACTBackground: The Outcome Rating Scale (ORS) is a measure frequently utilized in clinical practice settings to monitor client therapeutic progress and assess therapeutic outcomes. The ORS was designed to be used in clinical practice; therefore, demonstration of adequate reliability and evidence of validity with clinical populations is ideal. To our knowledge, there have been no reviews evaluating the overall adequacy of the psychometric properties of the ORS specific to its use with clinical populations.Purpose: The aim of this study was to review all available articles presenting information about the psychometric properties of the ORS to examine its usefulness with clinical populations.Methods: We completed an electronic literature search of several online databases in order to identify relevant articles. We identified 24 articles that met our inclusion criteria and analyzed the reliability and validity evidence for the ORS with clinical populations.Results: Findings showed moderately high to high internal consistency for the ORS and support for the ORS as a screening measure and monitoring tool for subjective symptoms of psychological distress. However, there is insufficient evidence to support the use of the ORS as a diagnostic tool or for assessing behavioral changes or outcomes.Discussion: Clinicians should be aware of the concurrent validity results indicating that the ORS may be best thought of as closer to a measure of quality of life as well as a potential screening tool for depressive symptoms. Future research efforts should focus on validation of the ORS with larger and more diverse clinical samples.

From runs to patterns

Previous work related to runs is extended to include various patterns. The familiar CSCF, CSTF and TSCSTFCF procedures for reliability demonstration tests are generalized for patterns. The waiting time distributions and the value of the expected number of required tests are presented. Like for runs, some auxiliary functions are defined, a set of equations is set up and a numerical solution is presented. In some cases, closed-form expressions are provided. The analysis is generalized for the case of testing a number of units in parallel. Following the case of runs, a constrained optimization procedure is shown for evaluating the optimal values of the parameters involved within the procedure. It is observed that in some cases it is preferable to deal with patterns instead of runs. In addition, the following problem is solved: given ‘i’ successes within ‘n’ tests, what is the probability of not having a certain number of kcs consecutive successes within a given pattern.

탄약고 장기 저장 유도탄의 신뢰성 입증시험 설계 방안

탄약고 장기 저장 유도탄의 신뢰성 입증시험 설계 방안

Study on Construction Method of High-Voltage Transmission Tower Beneath Shallow-Buried Tunnel

Wangqiao tunnel of Jiu-jing-qu railway is used as engineering example, based on risk analysis, aim at the construction scheme, comprehensive analysis and calculation has carried on combined monitoring and numerical analysis. Reliability demonstration has conducted on comprehensive construction scheme of” ground surface grunting consolidation & mechanical excavation & improving support measure & settlement monitoring”. Practice has proved that the deformation of the tunnel’s settlement of the arch and the high-voltage transmission tower were in allowable ranges, and good economic and technical results are obtained, the results can provide a reference for similar projects.

New statistical formulations for determination of qualification test plans of safety instrumented systems (SIS) subject to low/high operational demands

This paper aims to develop new statistical formulations to design efficient reliability demonstration test (RDT) plans for electrical/electronic and programmable electronic (E/E/ES) safety instrumented systems (SIS) subject to requirements of IEC 61508-1 (2010) standard.11IEC 61508-1:2010. Functional safety of electrical/electronic/programmable electronic (E/E/ES) safety-related systems. Source: http://www.iec.ch/functionalsafety/standards/ A case study is presented to show how the proposed statistical formulations can be employed to design RDT plans to validate whether SIS target mission reliability (TMR) can be met under a specified confidence level. Discussions includes trade-offs between test duration and number of units on test and sensitivity studies showing how the demonstrated reliability at end of mission life is impacted by SIS operational mode and key statistical parameters. The major contributions that this research offers are: (i) A framework to guide reliability practitioners in applying the proposed statistical formulations to design optimum RDT plans and articulate mission reliability statements (MRS) to support regulatory certification of new SIS designs. (ii) A methodology, demonstrated by a practical case study, to show how RDT plans can be designed to meet targets set by the applicable standards. The developed framework is robust and can support certification of safety systems in a wide variety of industrial applications.

Why is Clinical fMRI in a Resting State?

While resting state fMRI (rs-fMRI) has gained widespread application in neuroimaging clinical research, its penetration into clinical medicine has been more limited. We surveyed a neuroradiology professional group to ascertain their experience with rs-fMRI, identify perceived barriers to using rs-fMRI clinically and elicit suggestions about ways to facilitate its use in clinical practice. The electronic survey also collected information about demographics and work environment using Likert scales. We found that 90% of the respondents had adequate equipment to conduct rs-fMRI and 82% found rs-fMRI data easy to collect. Fifty-nine percent have used rs-fMRI in their past research and 72% reported plans to use rs-fMRI for research in the next year. Nevertheless, only 40% plan to use rs-fMRI in clinical practice in the next year and 82% agreed that their clinical fMRI use is largely confined to pre-surgical planning applications. To explore the reasons for the persistent low utilization of rs-fMRI in clinical applications, we identified barriers to clinical rs-fMRI use related to the availability of robust denoising procedures, single-subject analysis techniques, demonstration of functional connectivity map reliability, regulatory clearance, reimbursement, and neuroradiologist training opportunities. In conclusion, while rs-fMRI use in clinical neuroradiology practice is limited, enthusiasm appears to be quite high and there are several possible avenues in which further research and development may facilitate its penetration into clinical practice.

Triangular cyclic accelerated degradation zero-failure test plan

Purpose Zero-failure reliability testing aims at demonstrating whether the product has achieved the desired reliability target with zero failure and high confidence level at a given time. Incorporating accelerated degradation testing in zero-failure reliability demonstration test (RDT) facilitates early failure in high reliability items developed within short period of time to be able to survive in fiercely competitive market. The paper aims to discuss these issues. Design/methodology/approach The triangular cyclic stress uses one test chamber thus saving experimental cost. The parameters in model are estimated using maximum likelihood methods. The optimum plan consists in finding out optimum number of cycles, optimum specimens, optimum stress change point(s) and optimum stress rates. Findings The optimum plan consists in finding out optimum number of cycles, optimum specimens, optimum stress change point(s) and optimum stress rates by minimizing asymptotic variance of estimate of quantile of the lifetime distribution at use condition subject to the constraint that total testing or experimental cost does not exceed a pre-specified budget. Confidence intervals of the design parameters have been obtained and sensitivity analysis carried out. The results of sensitivity analysis show that the plan is robust to small deviations from the true values of baseline parameters. Originality/value For some highly reliable products, even accelerated life testing yields little failure data of units in a feasible amount of time. In such cases accelerated degradation testing is carried out, wherein the failure termed as soft failure is defined in terms of performance characteristic of the product exceeding its critical (threshold) value.

System Reliability Growth Analysis during Warranty

This paper presents system reliability growth analysis using actual field failure data. The primary objective of the system reliability growth is to improve the achievement of system reliability performance during system reliability demonstration, in order to achieve the predicted or contractually required system reliability commitment. An effective reliability growth model can be utilized to predict when the reliability target can be achieved based on previous reliability performance. In this paper, the system reliability growth analysis is illustrated using the Duane and AMSAA reliability growth models to determine applicability and aid in choice determination. The Duane model is a better choice for failure terminated reliability growth while AMSAA is a better choice for time terminated reliability growth. Comparisons of the Duane versus AMSAA model are carried out by conducting the statistical analysis on the observed field failures.

A test reduction strategy for reliability demonstration

Reliability demonstration always includes experimental approaches, which are expensive in terms of costs and duration.Failure Modes and their effects analysis allows a prioritization of the tests to perform by assessing the criticality of the failure modes.Accelerated testing methods combined with design of experiment and progressive results analysis can highlight the weaknesses of the product.By that way, experimental strategy can be defined to converge to the reliability objectives with the most efficient number of tests.Integrating experience feedback in the test protocol might also improve the test strategy, and Bayesian methodology can also be used to specify the tests needed to demonstrate the reliability target.This paper aims to present a methodology of test reduction, which has been applied on real industrial cases in whole or in part. However, since results cannot be disclosed, no real application will be presented in the paper.

Explore One Factor of Affecting Software Reliability Demonstration Testing Result

Explore One Factor of Affecting Software Reliability Demonstration Testing Result

A cost-driven reliability demonstration plan based on accelerated degradation tests

Reliability demonstration tests (RDTs) have been widely adopted to verify reliability requirements of manufacturing products. In practice, due to the limited resource and tight development schedule for new products, it is preferable to determine the decision variables including the termination time and the sample size for the RDT in advance. Existing degradation models often fail to capture the nonlinear degradation characteristics of testing items with complicated degradation mechanisms. This paper proposes a reliability demonstration method using an accelerated degradation test (ADT) in the context of a nonlinear random-coefficients model. First, we present the capabilities of the proposed ADT model to degradation data. Then, the cost-effective RDT plan is derived based on two types of decision risks and reliability requirements from both producers and customers, while meeting certain testing time constraints. The proposed method is illustrated using two practical examples. Finally, sensitivity analysis is provided to evaluate the robustness of the proposed RDT plan using ADT data.

Bayesian Methods for Reliability Demonstration Test for Finite Population Using Lot and Sequential Sampling

The work proposed a reliability demonstration test (RDT) process, which can be employed to determine whether a finite population is accepted or rejected. Bayesian and non-Bayesian approaches were compared in the proposed RDT process, as were lot and sequential sampling. One-shot devices, such as bullets, fire extinguishers, and grenades, were used as test targets, with their functioning state expressible as a binary model. A hypergeometric distribution was adopted as the likelihood function for a finite population consisting of binary items. It was demonstrated that a beta-binomial distribution was the conjugate prior of the hypergeometric likelihood function. According to the Bayesian approach, the posterior beta-binomial distribution is used to decide on the acceptance or rejection of the population in the RDT. The proposed method in this work could be used to select item providers in a supply chain, who guarantee a predetermined reliability target and confidence level. Numerical examples show that a Bayesian approach with sequential sampling has the advantage of only requiring a small sample size to determine the acceptance of a finite population.

Between-session reliability of opto-electronic motion capture in measuring sagittal posture and 3-D ranges of motion of the thoracolumbar spine

This study evaluated between-session reliability of opto-electronic motion capture to measure trunk posture and three-dimensional ranges of motion (ROM). Nineteen healthy participants aged 24–74 years underwent spine curvature, pelvic tilt and trunk ROM measurements on two separate occasions. Rigid four-marker clusters were attached to the skin overlying seven spinous processes, plus single markers on pelvis landmarks. Rigid body rotations of spine marker clusters were calculated to determine neutral posture and ROM in flexion, extension, total lateral bending (left-right) and total axial rotation (left-right). Segmental spine ROM values were in line with previous reports using opto-electronic motion capture. Intraclass correlation coefficients (ICC) and standard error of measurement (SEM) were calculated as measures of between-session reliability and measurement error, respectively. Retroreflective markers showed fair to excellent between-session reliability to measure thoracic kyphosis, lumbar lordosis, and pelvic tilt (ICC = 0.82, 0.63, and 0.54, respectively). Thoracic and lumbar segments showed highest reliabilities in total axial rotation (ICC = 0.78) and flexion-extension (ICC = 0.77–0.79) ROM, respectively. Pelvic segment showed highest ICC values in flexion (ICC = 0.78) and total axial rotation (ICC = 0.81) trials. Furthermore, it was estimated that four or fewer repeated trials would provide good reliability for key ROM outcomes, including lumbar flexion, thoracic and lumbar lateral bending, and thoracic axial rotation. This demonstration of reliability is a necessary precursor to quantifying spine kinematics in clinical studies, including assessing changes due to clinical treatment or disease progression.

Assessment methodology for urban excess heat recovery solutions in energy-efficient District Heating Networks

A large amount of low-temperature urban excess heat sources are available to play a fundamental role in the decarbonisation of the heating sector and the present and future of District Heating Networks (DHNs). This work, in the context of the ReUseHeat project, defines a performance assessment procedure applied to four advanced heat recovery solutions from data centres, hospital cooling systems, sewage water networks and underground stations. Key Performance Indicators are defined to allow for integral evaluation in line with the Smart Cities Information System guidelines. The proposed methodology will sustain reliable demonstration results and facilitate replication towards more energy-efficient DHNs.

RAMS FOR RAILWAY TURNOUTS

The Specification and Demonstration of Reliability, Availability, Maintainability and Safety is an important issue for the integration of the railway system in the European Union. Rail's analysis of railways shows the necessity to design railway lines with the safety and accessibility of railways. RAMS needs to maintain on the railway line the unsatisfactoriness and rigidity of subwoofer and the highest quality of maintenance and operation.

The Earth’s Magnetic Field and Visual Landmarks Steer Migratory Flight Behavior in the Nocturnal Australian Bogong Moth

Like many birds [1], numerous species of nocturnal moths undertake spectacular long-distance migrations at night [2]. Each spring, billions of Bogong moths (Agrotis infusa) escape hot conditions in different regions of southeast Australia by making a highly directed migration of over 1,000km to a limited number of cool caves in the Australian Alps, historically used for aestivating over the summer [3, 4]. How moths determine the direction of inherited migratory trajectories at night and locate their destination (i.e., navigate) is currently unknown [5-7]. Here we show that Bogong moths can sense the Earth's magnetic field and use it in conjunction with visual landmarks to steer migratory flight behavior. By tethering migrating moths in an outdoor flight simulator [8], we found that their flight direction turned predictably when dominant visual landmarks and a natural Earth-strength magnetic field were turned together, but that the moths became disoriented within a few minutes when these cues were set in conflict. We thus conclude that Bogong moths, like nocturnally migrating birds [9], can use a magnetic sense. Our results represent the first reliable demonstration of the use of the Earth's magnetic field to steer flight behavior in a nocturnal migratory insect.

Nuclear safety-critical Digital Instrumentation and Control system software: Reliability demonstration

A software reliability demonstration method was designed for the modeling and analysis of nuclear safety-critical Digital Instrumentation and Control (DI&C) system software. A “Reliability Demonstration of Safety-critical Software, RDSS” platform based on the Claim-Argument-Evidence (CAE) is presented to help the analysts for the analysis and evaluation of the software reliability. A novel method transformed the CAE method into Bayesian Brief Network (BBN) was proposed for the mining of the most sensitive elements (Evidence) in the DI&C system by sensitivity analysis with three reasoning methods. Moreover, this paper proposes an engineering approach for the identification of the vulnerability elements which influenced the reliability of DI&C system software life cycle.

To control and build trust: How managers use organizational controls and trust-building activities to motivate subordinate cooperation

This paper describes how managers attempt to motivate subordinate cooperation through the actions they take to apply controls and build trust. Results obtained from interviews and a survey of practicing managers detail how managers work to motivate particular types of subordinate cooperation using specific forms of control and demonstrations of their trustworthiness. These results also indicate that relationships between the forms of cooperation managers seek to promote and their demonstrations of trustworthiness are mediated by the controls they apply. Three relationships are identified in this study. Managers' applications of results controls mediate the relationship between their desires to motivate superior-subordinate work coordination and their demonstrations of reliability; 2. Managers' applications of action controls mediate the relationship between their desires to motivate subordinate job engagement and their demonstrations of competence; 3. Managers' applications of personnel controls mediate the relationship between their desires to motivate positive interpersonal relationships with their subordinates and their demonstrations of benevolence. These findings advance our knowledge of fundamental relationships in control-trust dynamics by presenting observations of managers' trust-building activities, displaying how managers' trust-building activities are related to the controls they apply, and delineating how managers attempt to motivate subordinate cooperation through applications of particular forms of controls and demonstrations of their trustworthiness.

Reliability of In Vitro Methods Used to Measure Intrinsic Clearance of Hydrophobic Organic Chemicals by Rainbow Trout: Results of an International Ring Trial.

In vitro assays are widely employed to obtain intrinsic clearance estimates used in toxicokinetic modeling efforts. However, the reliability of these methods is seldom reported. Here we describe the results of an international ring trial designed to evaluate two in vitro assays used to measure intrinsic clearance in rainbow trout. An important application of these assays is to predict the effect of biotransformation on chemical bioaccumulation. Six laboratories performed substrate depletion experiments with cyclohexyl salicylate, fenthion, 4-n-nonylphenol, deltamethrin, methoxychlor, and pyrene using cryopreserved hepatocytes and liver S9 fractions from trout. Variability within and among laboratories was characterized as the percent coefficient of variation (CV) in measured in vitro intrinsic clearance rates (CLIN VITRO, INT; ml/h/mg protein or 106 cells) for each chemical and test system. Mean intralaboratory CVs for each test chemical averaged 18.9% for hepatocytes and 14.1% for S9 fractions, whereas interlaboratory CVs (all chemicals and all tests) averaged 30.1% for hepatocytes and 22.4% for S9 fractions. When CLIN VITRO, INT values were extrapolated to in vivo intrinsic clearance estimates (CLIN VIVO, INT; l/d/kg fish), both assays yielded similar levels of activity (<4-fold difference for all chemicals). Hepatic clearance rates (CLH; l/d/kg fish) calculated using data from both assays exhibited even better agreement. These findings show that both assays are highly reliable and suggest that either may be used to inform chemical bioaccumulation assessments for fish. This study highlights several issues related to the demonstration of assay reliability and may provide a template for evaluating other in vitro biotransformation assays.

Sterility Testing of Immonobiological Medicinal Products in Russia. Historical Background and Current Requirements

Sterility is one of the key parameters of biological safety of immunobiological medicinal products. The article traces the history of the development of sterility test methods for immunobiological medicinal products from as far back as 1961 and up to the current requirements laid down in the State Pharmacopoeia of the Russian Federation, 13th edition. The article provides a detailed analysis of major approaches to the improvement of medicines quality evaluation based on this parameter, namely to the choice of: optimal growth media and methods of their evaluation, sensitive test strains, incubation conditions, the number of test samples (i.e., sample size) required for reliable demonstration of batch sterility; as well as approaches to the development of a test design that would accommodate specific aspects of production and use of immunobiological products. The article dwells upon the longstanding use of the sterility testing scheme developed in the national agency for control of immunobiological products — L.A. Tarasevich State Institute for Standardization and Control of Medicinal Immunobiological Products. The article analyses the current status of harmonisation of requirements for sterility testing of immunobiological products and other groups of medicines with those of the leading world pharmacopoeias, and prospects of using these requirements in the Eurasian Economic Union.