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Sample records for achieve reliable results

  1. Reliability achievement in high technology space systems

    NASA Technical Reports Server (NTRS)

    Lindstrom, D. L.

    1981-01-01

    The production of failure-free hardware is discussed. The elements required to achieve such hardware are: technical expertise to design, analyze, and fully understand the design; use of high reliability parts and materials control in the manufacturing process; and testing to understand the system and weed out defects. The durability of the Hughes family of satellites is highlighted.

  2. Understanding the Elements of Operational Reliability: A Key for Achieving High Reliability

    NASA Technical Reports Server (NTRS)

    Safie, Fayssal M.

    2010-01-01

    This viewgraph presentation reviews operational reliability and its role in achieving high reliability through design and process reliability. The topics include: 1) Reliability Engineering Major Areas and interfaces; 2) Design Reliability; 3) Process Reliability; and 4) Reliability Applications.

  3. Achieving Reliable Communication in Dynamic Emergency Responses

    PubMed Central

    Chipara, Octav; Plymoth, Anders N.; Liu, Fang; Huang, Ricky; Evans, Brian; Johansson, Per; Rao, Ramesh; Griswold, William G.

    2011-01-01

    Emergency responses require the coordination of first responders to assess the condition of victims, stabilize their condition, and transport them to hospitals based on the severity of their injuries. WIISARD is a system designed to facilitate the collection of medical information and its reliable dissemination during emergency responses. A key challenge in WIISARD is to deliver data with high reliability as first responders move and operate in a dynamic radio environment fraught with frequent network disconnections. The initial WIISARD system employed a client-server architecture and an ad-hoc routing protocol was used to exchange data. The system had low reliability when deployed during emergency drills. In this paper, we identify the underlying causes of unreliability and propose a novel peer-to-peer architecture that in combination with a gossip-based communication protocol achieves high reliability. Empirical studies show that compared to the initial WIISARD system, the redesigned system improves reliability by as much as 37% while reducing the number of transmitted packets by 23%. PMID:22195075

  4. Methods and Costs to Achieve Ultra Reliable Life Support

    NASA Technical Reports Server (NTRS)

    Jones, Harry W.

    2012-01-01

    A published Mars mission is used to explore the methods and costs to achieve ultra reliable life support. The Mars mission and its recycling life support design are described. The life support systems were made triply redundant, implying that each individual system will have fairly good reliability. Ultra reliable life support is needed for Mars and other long, distant missions. Current systems apparently have insufficient reliability. The life cycle cost of the Mars life support system is estimated. Reliability can be increased by improving the intrinsic system reliability, adding spare parts, or by providing technically diverse redundant systems. The costs of these approaches are estimated. Adding spares is least costly but may be defeated by common cause failures. Using two technically diverse systems is effective but doubles the life cycle cost. Achieving ultra reliability is worth its high cost because the penalty for failure is very high.

  5. Goal Setting to Achieve Results

    ERIC Educational Resources Information Center

    Newman, Rich

    2012-01-01

    Both districts and individual schools have a very clear set of goals and skills for their students to achieve and master. In fact, except in rare cases, districts and schools develop very detailed goals they wish to pursue. In most cases, unfortunately, only the teachers and staff at a particular school or district-level office are aware of the…

  6. On the reliability of reverse engineering results.

    PubMed

    Amotchkina, Tatiana V; Trubetskov, Michael K; Pervak, Vladimir; Romanov, Boris; Tikhonravov, Alexander V

    2012-08-01

    Determination of actual parameters of manufactured optical coatings (reverse engineering of optical coatings) provides feedback to the design-production chain and thus plays an important role in raising the quality of optical coatings production. In this paper, the reliability of reverse engineering results obtained using different types of experimental data is investigated. Considered experimental data include offline normal incidence transmittance data, offline ellipsometric data, and online transmittance monitoring data recorded during depositions of all coating layers. Experimental data are obtained for special test quarter-wave mirrors with intentional errors in some layers. These mirrors were produced by a well-calibrated magnetron-sputtering process. The intentional errors are several times higher than estimated errors of layer thickness monitoring, and the reliability of their detection is used as a measure of reliability of reverse engineering results. It is demonstrated that the most reliable results are provided by online transmittance data.

  7. Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH) program

    NASA Technical Reports Server (NTRS)

    Fayette, Daniel F.; Speicher, Patricia; Stoklosa, Mark J.; Evans, Jillian V.; Evans, John W.; Gentile, Mike; Pagel, Chuck A.; Hakim, Edward

    1993-01-01

    A joint military-commercial effort to evaluate multichip module (MCM) structures is discussed. The program, Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH), has been designed to identify the failure mechanisms that are possible in MCM structures. The RELTECH test vehicles, technical assessment task, product evaluation plan, reliability modeling task, accelerated and environmental testing, and post-test physical analysis and failure analysis are described. The information obtained through RELTECH can be used to address standardization issues, through development of cost effective qualification and appropriate screening criteria, for inclusion into a commercial specification and the MIL-H-38534 general specification for hybrid microcircuits.

  8. SLAC modulator system improvements and reliability results

    SciTech Connect

    Donaldson, A.R.

    1998-06-01

    In 1995, an improvement project was completed on the 244 klystron modulators in the linear accelerator. The modulator system has been previously described. This article offers project details and their resulting effect on modulator and component reliability. Prior to the project, the authors had collected four operating cycles (1991 through 1995) of MTTF data. In this discussion, the '91 data will be excluded since the modulators operated at 60 Hz. The five periods following the '91 run were reviewed due to the common repetition rate at 120 Hz.

  9. Achieving High Reliability Operations Through Multi-Program Integration

    SciTech Connect

    Holly M. Ashley; Ronald K. Farris; Robert E. Richards

    2009-04-01

    Over the last 20 years the Idaho National Laboratory (INL) has adopted a number of operations and safety-related programs which has each periodically taken its turn in the limelight. As new programs have come along there has been natural competition for resources, focus and commitment. In the last few years, the INL has made real progress in integrating all these programs and are starting to realize important synergies. Contributing to this integration are both collaborative individuals and an emerging shared vision and goal of the INL fully maturing in its high reliability operations. This goal is so powerful because the concept of high reliability operations (and the resulting organizations) is a masterful amalgam and orchestrator of the best of all the participating programs (i.e. conduct of operations, behavior based safety, human performance, voluntary protection, quality assurance, and integrated safety management). This paper is a brief recounting of the lessons learned, thus far, at the INL in bringing previously competing programs into harmony under the goal (umbrella) of seeking to perform regularly as a high reliability organization. In addition to a brief diagram-illustrated historical review, the authors will share the INL’s primary successes (things already effectively stopped or started) and the gaps yet to be bridged.

  10. Getting to Results. Closing the Achievement Gap

    ERIC Educational Resources Information Center

    Read, Tory

    2008-01-01

    The "Closing the Achievement Gap" series explores the Casey Foundation's education investments and presents stories, results, and lessons learned. This publication describes efforts to develop a flexible but rigorous results measurements system that enables the Foundation and its grantees to reflect on practice and course-correct as…

  11. Exemplar pediatric collaborative improvement networks: achieving results.

    PubMed

    Billett, Amy L; Colletti, Richard B; Mandel, Keith E; Miller, Marlene; Muething, Stephen E; Sharek, Paul J; Lannon, Carole M

    2013-06-01

    A number of pediatric collaborative improvement networks have demonstrated improved care and outcomes for children. Regionally, Cincinnati Children's Hospital Medical Center Physician Hospital Organization has sustained key asthma processes, substantially increased the percentage of their asthma population receiving "perfect care," and implemented an innovative pay-for-performance program with a large commercial payor based on asthma performance measures. The California Perinatal Quality Care Collaborative uses its outcomes database to improve care for infants in California NICUs. It has achieved reductions in central line-associated blood stream infections (CLABSI), increased breast-milk feeding rates at hospital discharge, and is now working to improve delivery room management. Solutions for Patient Safety (SPS) has achieved significant improvements in adverse drug events and surgical site infections across all 8 Ohio children's hospitals, with 7700 fewer children harmed and >$11.8 million in avoided costs. SPS is now expanding nationally, aiming to eliminate all events of serious harm at children's hospitals. National collaborative networks include ImproveCareNow, which aims to improve care and outcomes for children with inflammatory bowel disease. Reliable adherence to Model Care Guidelines has produced improved remission rates without using new medications and a significant increase in the proportion of Crohn disease patients not taking prednisone. Data-driven collaboratives of the Children's Hospital Association Quality Transformation Network initially focused on CLABSI in PICUs. By September 2011, they had prevented an estimated 2964 CLABSI, saving 355 lives and $103,722,423. Subsequent improvement efforts include CLABSI reductions in additional settings and populations.

  12. Sharing Leadership Responsibilities Results in Achievement Gains

    ERIC Educational Resources Information Center

    Armistead, Lew

    2010-01-01

    Collective, not individual, leadership in schools has a greater impact on student achievement; when principals and teachers share leadership responsibilities, student achievement is higher; and schools having high student achievement also display a vision for student achievement and teacher growth. Those are just a few of the insights into school…

  13. Desert ants achieve reliable recruitment across noisy interactions.

    PubMed

    Razin, Nitzan; Eckmann, Jean-Pierre; Feinerman, Ofer

    2013-05-06

    We study how desert ants, Cataglyphis niger, a species that lacks pheromone-based recruitment mechanisms, inform each other about the presence of food. Our results are based on automated tracking that allows us to collect a large database of ant trajectories and interactions. We find that interactions affect an ant's speed within the nest. Fast ants tend to slow down, whereas slow ones increase their speed when encountering a faster ant. Faster ants tend to exit the nest more frequently than slower ones. So, if an ant gains enough speed through encounters with others, then she tends to leave the nest and look for food. On the other hand, we find that the probability for her to leave the nest depends only on her speed, but not on whether she had recently interacted with a recruiter that has found the food. This suggests a recruitment system in which ants communicate their state by very simple interactions. Based on this assumption, we estimate the information-theoretical channel capacity of the ants' pairwise interactions. We find that the response to the speed of an interacting nest-mate is very noisy. The question is then how random interactions with ants within the nest can be distinguished from those interactions with a recruiter who has found food. Our measurements and model suggest that this distinction does not depend on reliable communication but on behavioural differences between ants that have found the food and those that have not. Recruiters retain high speeds throughout the experiment, regardless of the ants they interact with; non-recruiters communicate with a limited number of nest-mates and adjust their speed following these interactions. These simple rules lead to the formation of a bistable switch on the level of the group that allows the distinction between recruitment and random noise in the nest. A consequence of the mechanism we propose is a negative effect of ant density on exit rates and recruitment success. This is, indeed, confirmed by our

  14. Validity and Reliability of Trichotomous Achievement Goal Scale

    ERIC Educational Resources Information Center

    Ilker, Gokce Erturan; Arslan, Yunus; Demirhan, Giyasettin

    2011-01-01

    The Trichotomous Achievement Goal Scale was developed by Agbuga and Xiang (2008) by including selected items from the scales of Duda and Nicholls (1992), Elliot (1999), and Elliot and Church (1997) and adapting them into Turkish. The scale consists of 18 items, and students rated each item on a 7-point Likert scale. To ascertain the validity and…

  15. The Reliability of Results from National Curriculum Testing in England

    ERIC Educational Resources Information Center

    Newton, Paul E.

    2009-01-01

    Background: National curriculum tests have been administered in England for well over a decade. Although reliability evidence has been published, critics have argued that there is not enough evidence (of the right kind) and that test results may be insufficiently reliable. Purpose: This article collates and discusses evidence on the reliability of…

  16. Gallbladder cancer: results achieved and future challenges.

    PubMed

    Di Carlo, Isidoro; Toro, Adriana

    2017-02-01

    26th World Congress of International Association of Surgeons Gastroenterologists and Oncologists, Seoul, South Korea, 8-10 September 2016 This year, the 26th World Congress of the International Association of Surgeons, Gastroenterologists, and Oncologists (IASGO) was hosted by Seoul in South Korea. The congress was extremely well organized, and the quality of the submissions and the relevance of the speakers were excellent. This report highlights the newest and most interesting results regarding the treatment of gallbladder tumors from the conference.

  17. Initial results of SEPAC scientific achievement

    NASA Technical Reports Server (NTRS)

    Obayashi, T.; Kawashima, N.; Sasaki, S.; Yanagisawa, M.; Kuriki, K.; Nagatomo, M.; Ninomiya, K.; Roberts, W. T.; Taylor, W. W. L.; Williamson, P. R.

    1985-01-01

    Electron beam injection of 5 keV, 300 mA (1.5 kW) and MPD arcjet plasma injection of 2 kJ/shot were successfully performed together with various kinds of diagnostic instruments including a high sensitivity TV camera observation in the Spacelab 1. Major scientific results obtained are studies of: (1) vehicle charge-up due to the electron beam emission and its neutralization by the MPD arcjet plasma; (2) beam-plasma interaction including the plasma wave excitation; (3) beam-atmosphere interaction such as the verification of critical velocity ionization effect; and (4) anomalous enhancement of ionization associated with a neutral gas injection into space.

  18. Development of Achievement Test: Validity and Reliability Study for Achievement Test on Matter Changing

    ERIC Educational Resources Information Center

    Kara, Filiz; Celikler, Dilek

    2015-01-01

    For "Matter Changing" unit included in the Secondary School 5th Grade Science Program, it is intended to develop a test conforming the gains described in the program, and that can determine students' achievements. For this purpose, a multiple-choice test of 48 questions is arranged, consisting of 8 questions for each gain included in the…

  19. Public Perceptions of Reliability in Examination Results in England

    ERIC Educational Resources Information Center

    He, Qingping; Boyle, Andrew; Opposs, Dennis

    2011-01-01

    Building on findings from existing qualitative research into public perceptions of reliability in examination results in England, a questionnaire was developed and administered to samples of teachers, students and employers to study their awareness of and opinions about various aspects of reliability quantitatively. Main findings from the study…

  20. Reliability worth assessment in a developing country - residential survey results

    SciTech Connect

    Billinton, R.; Pandey, M.

    1999-11-01

    This paper presents the results of a residential customer survey conducted in service areas of the Nepal Integrated Electric Power System (NPS). The objective was to determine the power interruption costs incurred by the residential customers of a developing country, and extend the customer survey approach to reliability worth evaluation in a developing environment. Interruption cost estimates were obtained using in-person interviews with 944 sample customers. The results indicate the implications of service reliability to residential customers of Nepal, and show that reliability worth evaluation in a developing country is both possible and practical.

  1. Notification: Review of Science to Achieve Results (STAR) Grant Program

    EPA Pesticide Factsheets

    Project #OA-FY12-0606, July 16, 2012. EPA’s Office of Inspector General (OIG) plans to begin preliminary research for an audit of grants awarded under EPA’s Science to Achieve Results (STAR) program.

  2. The Stories Clinicians Tell: Achieving High Reliability and Improving Patient Safety

    PubMed Central

    Cohen, Daniel L; Stewart, Kevin O

    2016-01-01

    The patient safety movement has been deeply affected by the stories patients have shared that have identified numerous opportunities for improvements in safety. These stories have identified system and/or human inefficiencies or dysfunctions, possibly even failures, often resulting in patient harm. Although patients’ stories tell us much, less commonly heard are the stories of clinicians and how their personal observations regarding the environments they work in and the circumstances and pressures under which they work may degrade patient safety and lead to harm. If the health care industry is to function like a high-reliability industry, to improve its processes and achieve the outcomes that patients rightly deserve, then leaders and managers must seek and value input from those on the front lines—both clinicians and patients. Stories from clinicians provided in this article address themes that include incident identification, disclosure and transparency, just culture, the impact of clinical workload pressures, human factors liabilities, clinicians as secondary victims, the impact of disruptive and punitive behaviors, factors affecting professional morale, and personal failings. PMID:26580146

  3. Design features and results from fatigue reliability research machines.

    NASA Technical Reports Server (NTRS)

    Lalli, V. R.; Kececioglu, D.; Mcconnell, J. B.

    1971-01-01

    The design, fabrication, development, operation, calibration and results from reversed bending combined with steady torque fatigue research machines are presented. Fifteen-centimeter long, notched, SAE 4340 steel specimens are subjected to various combinations of these stresses and cycled to failure. Failure occurs when the crack in the notch passes through the specimen automatically shutting down the test machine. These cycles-to-failure data are statistically analyzed to develop a probabilistic S-N diagram. These diagrams have many uses; a rotating component design example given in the literature shows that minimum size and weight for a specified number of cycles and reliability can be calculated using these diagrams.

  4. Confirmation of PM typing protocols for consistent and reliable results.

    PubMed

    Crouse, C A; Nippes, D C; Ritzline, E L

    1996-05-01

    A recent report in the Perkin Elmer "Forensic Forum" bulletin described a modification to the previously published PM typing protocol indicating that in order to obtain consistent and reliable PM and DQA1 typing results, disodium EDTA should be added to the post-amplification mixture before denaturation of the DNA fragments. The analysis and validation of this suggestion is described in the accompanying paper. We report the evaluation of this additional step when typing for PM alleles and conclude that the standard operating procedures currently enforced at the Palm Beach County Sheriff's Office and Indian River crime laboratories do not necessitate the need for the addition of disodium EDTA to the PM amplified products prior to the heat denaturation step. Further, depending on an individual laboratory's PM protocol, the recommendation by Perkin Elmer to add disodium EDTA to PM amplified products before typing has merit and should be carefully considered when determining laboratory PM typing protocols.

  5. Fair and Just Culture, Team Behavior, and Leadership Engagement: The Tools to Achieve High Reliability

    PubMed Central

    Frankel, Allan S; Leonard, Michael W; Denham, Charles R

    2006-01-01

    Background Disparate health care provider attitudes about autonomy, teamwork, and administrative operations have added to the complexity of health care delivery and are a central factor in medicine's unacceptably high rate of errors. Other industries have improved their reliability by applying innovative concepts to interpersonal relationships and administrative hierarchical structures (Chandler 1962). In the last 10 years the science of patient safety has become more sophisticated, with practical concepts identified and tested to improve the safety and reliability of care. Objective Three initiatives stand out as worthy regarding interpersonal relationships and the application of provider concerns to shape operational change: The development and implementation of Fair and Just Culture principles, the broad use of Teamwork Training and Communication, and tools like WalkRounds that promote the alignment of leadership and frontline provider perspectives through effective use of adverse event data and provider comments. Methods Fair and Just Culture, Teamwork Training, and WalkRounds are described, and implementation examples provided. The argument is made that they must be systematically and consistently implemented in an integrated fashion. Conclusions There are excellent examples of institutions applying Just Culture principles, Teamwork Training, and Leadership WalkRounds—but to date, they have not been comprehensively instituted in health care organizations in a cohesive and interdependent manner. To achieve reliability, organizations need to begin thinking about the relationship between these efforts and linking them conceptually. PMID:16898986

  6. Updating the reference population to achieve constant genomic prediction reliability across generations.

    PubMed

    Pszczola, M; Calus, M P L

    2016-06-01

    The reliability of genomic breeding values (DGV) decays over generations. To keep the DGV reliability at a constant level, the reference population (RP) has to be continuously updated with animals from new generations. Updating RP may be challenging due to economic reasons, especially for novel traits involving expensive phenotyping. Therefore, the goal of this study was to investigate a minimal RP update size to keep the reliability at a constant level across generations. We used a simulated dataset resembling a dairy cattle population. The trait of interest was not included itself in the selection index, but it was affected by selection pressure by being correlated with an index trait that represented the overall breeding goal. The heritability of the index trait was assumed to be 0.25 and for the novel trait the heritability equalled 0.2. The genetic correlation between the two traits was 0.25. The initial RP (n=2000) was composed of cows only with a single observation per animal. Reliability of DGV using the initial RP was computed by evaluating contemporary animals. Thereafter, the RP was used to evaluate animals which were one generation younger from the reference individuals. The drop in the reliability when evaluating younger animals was then assessed and the RP was updated to re-gain the initial reliability. The update animals were contemporaries of evaluated animals (EVA). The RP was updated in batches of 100 animals/update. First, the animals most closely related to the EVA were chosen to update RP. The results showed that, approximately, 600 animals were needed every generation to maintain the DGV reliability at a constant level across generations. The sum of squared relationships between RP and EVA and the sum of off-diagonal coefficients of the inverse of the genomic relationship matrix for RP, separately explained 31% and 34%, respectively, of the variation in the reliability across generations. Combined, these parameters explained 53% of the

  7. Results achieved in the treatment of patients with vestibular schwannoma.

    PubMed

    Freigang, Bernd; Rudolf, Jan

    2004-01-01

    Personal experience gathered with the treatment of 264 vestibular schwannoma (VS) at the Magdeburg University ENT Hospital is analysed. ABR Audiometry is useful as a screening, even though it yielded false-negative values in 12.7% (n = 33) for intrameatal VS and 16.9% for all VS, despite accurate evaluation. Latency increases of Waves I, III and V and their intraaural comparison exhibited a statistically significant difference for the VS levels proposed by TOS. The mean of intrameatal VS too was found to have longer latencies compared with the normal-hearing ears of the patients. In the individual case, with threshold hearing normal, anamnestic findings as well as otoneurological evidence provide an early indication for enhanced MRI, CISS imaging, or individual 3D reconstruction of the pontocerebellar cisterna. Adopting intraoperative monitoring of the facial nerve and the cochlea as well as the Pars acustica by means of far-field and near-field electrodes, a good facial 'mobility' was achieved in 95.3%, and a useful audition (AAO-HNS Types A and B) in 60%. Monitoring is beneficial as it enhances the reliability and improves the subtle preparation during surgery. The power of hearing improved postoperatively within six months and remained at a good level over two years. From our perspective, otorhinolaryngologists are the right specialists to attend to VS.

  8. [Experimental Conditions and Reliability Analysis of Results of COD components].

    PubMed

    Li, Zhi-hua; Zhang, Yin; Han, Xing; Yu, Ke; Li, Ru-jia

    2015-10-01

    The present study attempts to use SF( OUR(max)/OUR(en)) instead of S(0)/X(0) as an index of optimal initial conditions for determination of COD components by means of respirometry, thereby simplifying the measuring process and the operation can be automated. Further, the ratio of COD consumed by the growth of biomass can be used for the reliability assessment of results. Experimental results show that, experimental conditions for obtaining good results as follows: (1) for samples that composed of a large amount of easily biodegradable components (e. g., synthetic wastewater made by sodium acetate), SF should be in the range of 2.8 to 5.3, and the ratio of COD consumed by growth of biomass should be less than 30%; (2) for samples that composed of both readily biodegradable and slowly biodegradable components (i. e., typical domestic wastewater), SF should be in the range of 5.8 to 6.4, and the ratio of COD consumed by growth of biomass should be less than 30%; (3) and for samples that composed of a large amount of slowly biodegradable industrial wastewater (i. e., landfill leachate), SF should be 15 or less, and the ratio of COD consumed by growth of biomass should be approximately 40%. Therefore, when respirometry is used for the determination of COD components, the optimal conditions in terms of SF increase with the complexity of carbon source.

  9. Resource reliability, accessibility and governance: pillars for managing water resources to achieve water security in Nepal

    NASA Astrophysics Data System (ADS)

    Biggs, E. M.; Duncan, J.; Atkinson, P.; Dash, J.

    2013-12-01

    As one of the world's most water-abundant countries, Nepal has plenty of water yet resources are both spatially and temporally unevenly distributed. With a population heavily engaged in subsistence farming, whereby livelihoods are entirely dependent on rain-fed agriculture, changes in freshwater resources can substantially impact upon survival. The two main sources of water in Nepal come from monsoon precipitation and glacial runoff. The former is essential for sustaining livelihoods where communities have little or no access to perennial water resources. Much of Nepal's population live in the southern Mid-Hills and Terai regions where dependency on the monsoon system is high and climate-environment interactions are intricate. Any fluctuations in precipitation can severely affect essential potable resources and food security. As the population continues to expand in Nepal, and pressures build on access to adequate and clean water resources, there is a need for institutions to cooperate and increase the effectiveness of water management policies. This research presents a framework detailing three fundamental pillars for managing water resources to achieve sustainable water security in Nepal. These are (i) resource reliability; (ii) adequate accessibility; and (iii) effective governance. Evidence is presented which indicates that water resources are adequate in Nepal to sustain the population. In addition, aspects of climate change are having less impact than previously perceived e.g. results from trend analysis of precipitation time-series indicate a decrease in monsoon extremes and interannual variation over the last half-century. However, accessibility to clean water resources and the potential for water storage is limiting the use of these resources. This issue is particularly prevalent given the heterogeneity in spatial and temporal distributions of water. Water governance is also ineffective due to government instability and a lack of continuity in policy

  10. Reliability Sampling Plans: A Review and Some New Results

    ERIC Educational Resources Information Center

    Isaic-Maniu, Alexandru; Voda, Viorel Gh.

    2009-01-01

    In this work we present a large area of aspects related to the problem of sampling inspection in the case of reliability. First we discuss the actual status of this domain, mentioning the newest approaches (from a technical view point) such as HALT and HASS and the statistical perspective. After a brief description of the general procedure in…

  11. Initial results of the CD-1 reliable multicast experiment

    SciTech Connect

    Agarwal, D.; Stead, R.; Coan, B.; Burns, J. E.; Shah, N.; Kyriakopoulos, N.

    2000-09-29

    During the past year, an experiment has been underway to test use of reliable multicast capabilities for transmission of continuous data in the Global Communication Infrastructure. For the experiment a version of the CD-1 protocol was multicast enabled. The experiment has demonstrated the feasibility of transmitting data in a multicast mode over the GCI. In the case of the Comprehensive Nuclear Test-Ban Treaty the sender could be the station and the receivers the International Data Center (IDC) and one or more National Data Centers (NDC). The potential advantages of multicasting include (a) the timely receipt of the data by the IDC and the host NDC and (b) the simultaneous availability of the raw station data at, at least, two locations. The latter, by introducing redundant data paths, decreases the probability of loss of station data due to a potential failure of a single data receiver. This experiment is only one element of a needed more thorough assessment of the reliability and cost-effectiveness of introducing redundancies in the data transmission paths and the data sinks of the IMS. The next stage of the multicast experiment planned is installation of the multicast-enabled CD-1 software at the GERES IMS station, at the German NDC and at the IDC for further experiments with actual IMS station data. This stage of the experiment is waiting on installation of a GCI link to the German NDC. Negotiations regarding price for this installation have been on going between the Global Communication Infrastructure (GCI) contractor and the German NDC with no resolution. Current development of the CD-x protocol is proceeding in two complementary directions. Along with the work on a multicast enabled version of CD-1 there is also work to develop CD-1.1, which will add end-to-end reliability to the CD-1 protocol among other things. A possible future activity would be to combine the reliable multicast and the end-to-end reliability mechanisms into one CD-x protocol version.

  12. The Value of Full Correction: Achieving Excellent and Affordable Results.

    PubMed

    Kaplan, Julie Bass

    2016-01-01

    Patients often come to medical aesthetic offices with hopes to fully correct lost facial volume and achieve a natural appearance. Unfortunately, the cost per syringe of dermal filler can be a barrier to desired outcomes. Many aesthetic practitioners do the best they can with the amount of product the patient can afford, often falling short of the "wow" effect for the patient. This article describes what one office implemented to solve the conundrum of affordability while still allowing offices to cover its own financial realities. This tool can help patients achieve beautiful, natural, and affordable outcomes while helping offices advance in manufacturer's tiers, improve word-of-mouth advertising, and increase job satisfaction.

  13. Higher Education Counts: Achieving Results, 2008. Executive Summary

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2008

    2008-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's system of higher education. Since 2000, the report has been the primary vehicle for reporting higher education's progress toward achieving six, statutorily-defined state goals: (1) To enhance student learning and promote academic excellence; (2) To join with…

  14. Higher Education Counts: Achieving Results. 2009 Executive Summary

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2009

    2009-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's system of higher education. Since 2000, the report has been the primary vehicle for reporting higher education's progress toward achieving six, statutorily-defined state goals: (1) To enhance student learning and promote academic excellence; (2) To join with…

  15. Higher Education Counts: Achieving Results. 2006 Executive Summary

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2006

    2006-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's system of higher education. Since 2000, the report has been the principle vehicle for reporting higher education's progress toward achieving six, statutorily-defined state goals: (1) To enhance student learning and promote academic excellence; (2) To join with…

  16. Higher Education Counts: Achieving Results. 2007 Executive Summary

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2007

    2007-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's system of higher education. Since 2000, the report has been the primary vehicle for reporting higher education's progress toward achieving six, statutorily-defined state goals: (1) To enhance student learning and promote academic excellence; (2) To join with…

  17. Effective Teaching Results in Increased Science Achievement for All Students

    ERIC Educational Resources Information Center

    Johnson, Carla C.; Kahle, Jane Butler; Fargo, Jamison D.

    2007-01-01

    This study of teacher effectiveness and student achievement in science demonstrated that effective teachers positively impact student learning. A general linear mixed model was used to assess change in student scores on the Discovery Inquiry Test as a function of time, race, teacher effectiveness, gender, and impact of teacher effectiveness in…

  18. Is It Really Possible to Test All Educationally Significant Achievements with High Levels of Reliability?

    ERIC Educational Resources Information Center

    Davis, Andrew

    2015-01-01

    PISA claims that it can extend its reach from its current core subjects of Reading, Science, Maths and problem-solving. Yet given the requirement for high levels of reliability for PISA, especially in the light of its current high stakes character, proposed widening of its subject coverage cannot embrace some important aspects of the social and…

  19. Reliability and Validity of the "Achievement Emotions Questionnaire": A Study of Argentinean University Students

    ERIC Educational Resources Information Center

    Paoloni, Paola Verónica; Vaja, Arabela Beatriz; Muñoz, Verónica Lilian

    2014-01-01

    Introduction: This paper aims at describing the psychometric features of the Achievement Emotions Questionnaire (AEQ), focusing specifically on the section that measures class emotions. From a theoretical perspective, this instrument was designed based on the control-value theory of achievement emotions. Therefore, a description of the…

  20. The UNISAT program: Lessons learned and achieved results

    NASA Astrophysics Data System (ADS)

    Santoni, Fabio; Piergentili, Fabrizio; Graziani, Filippo

    2009-07-01

    More than ten years experience in hands-on space education has been achieved at Scuola di Ingegneria Aerospaziale of Università di Roma "la Sapienza", where the UNISAT program was established in the early nineties. The students participating in this program are involved in a microsatellite design, manufacturing, test, launch and operation in orbit activity, from initial mission concept to operation in orbit. The microsatellite program develops in a two years timeline, fitting with the graduate student program curricular activity at Scuola di Ingegneria Aerospaziale. Four microsatellites have been launched every other year since 2000 from the Baikonour Cosmodrome by the DNEPR LV. In this way there was the opportunity to exploit the UNISAT platform to perform small scientific and technological experiments in orbit. Besides education, a main goal of the UNISAT program is testing in orbit commercial off-the-shelf components, which allow to keep the program cost low and compatible with the University research budget. The main spacecraft subsystems, including the in orbit technological and scientific experiments, and the ground station operations are briefly described in the paper, focussing on the education and research aspects.

  1. Laser welding of automotive aluminum alloys to achieve defect-free, structurally sound and reliable welds

    SciTech Connect

    DebRoy, T.

    2000-11-17

    The objective of this program was to seek improved process control and weldment reliability during laser welding of automotive aluminum alloys while retaining the high speed and accuracy of the laser beam welding process. The effects of various welding variables on the loss of alloying elements and the formation of porosity and other geometric weld defects such as underfill and overfill were studied both experimentally and theoretically.

  2. DOD Role in Counterdrug Operations -- Can We Achieve Better Results?

    DTIC Science & Technology

    1999-04-01

    ORGANIZATION REPORT NUMBER 9 . SPONSORING/MONITORING AGENCY NAME AND ADDRESS , 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12... 9 THE UNITED STATES DRUG PROBLEM ................................................................... 11 Cost to...national counterdrug strategy, is fiscally possible and would provide better results. 9 Chapter 1 Introduction Our specific mission is to protect national

  3. Student Achievement in Science: A Comparison of National Assessment Results.

    ERIC Educational Resources Information Center

    Rakow, Steven J.; And Others

    1984-01-01

    Students' understanding of basic science concepts (with particular emphasis on the interaction of science and society) was measured during a 1981-82 national assessment. These results are compared to those obtained from the Third Science Assessment (1977) to determine how students' knowledge has changed during the past five years. (JN)

  4. Increased Reliability for Single-Case Research Results: Is the Bootstrap the Answer?

    ERIC Educational Resources Information Center

    Parker, Richard I.

    2006-01-01

    There is need for objective and reliable single-case research (SCR) results in the movement toward evidence-based interventions (EBI), for inclusion in meta-analyses, and for funding accountability in clinical contexts. Yet SCR deals with data that often do not conform to parametric data assumptions and that yield results of low reliability. A…

  5. Reliability and Validity Evidence for Achievement Goal Models in High School Physical Education Settings

    ERIC Educational Resources Information Center

    Guan, Jianmin; McBride, Ron; Xiang, Ping

    2007-01-01

    Although empirical research in academic areas provides support for both a 3-factor as well as a 4-factor achievement goal model, both models were proposed and tested with a collegiate sample. Little is known about the generalizability of either model with high school level samples. This study was designed to examine whether the 3-factor model…

  6. Reliability worth assessment in a developing country - commercial and industrial survey results

    SciTech Connect

    Pandey, M.; Billinton, R.

    1999-11-01

    This paper presents the results of an investigation conducted to determine the costs of electric service interruptions in the commercial and industrial sectors of a developing country. The investigation used in-person interviews of 800 businesses and 300 industries in Nepal. The results indicate the customer implications of service reliability, and show that electric service reliability worth can be assessed in a developing country.

  7. Results of a Demonstration Assessment of Passive System Reliability Utilizing the Reliability Method for Passive Systems (RMPS)

    SciTech Connect

    Bucknor, Matthew; Grabaskas, David; Brunett, Acacia; Grelle, Austin

    2015-04-26

    Advanced small modular reactor designs include many advantageous design features such as passively driven safety systems that are arguably more reliable and cost effective relative to conventional active systems. Despite their attractiveness, a reliability assessment of passive systems can be difficult using conventional reliability methods due to the nature of passive systems. Simple deviations in boundary conditions can induce functional failures in a passive system, and intermediate or unexpected operating modes can also occur. As part of an ongoing project, Argonne National Laboratory is investigating various methodologies to address passive system reliability. The Reliability Method for Passive Systems (RMPS), a systematic approach for examining reliability, is one technique chosen for this analysis. This methodology is combined with the Risk-Informed Safety Margin Characterization (RISMC) approach to assess the reliability of a passive system and the impact of its associated uncertainties. For this demonstration problem, an integrated plant model of an advanced small modular pool-type sodium fast reactor with a passive reactor cavity cooling system is subjected to a station blackout using RELAP5-3D. This paper discusses important aspects of the reliability assessment, including deployment of the methodology, the uncertainty identification and quantification process, and identification of key risk metrics.

  8. Formal design and verification of a reliable computing platform for real-time control. Phase 1: Results

    NASA Technical Reports Server (NTRS)

    Divito, Ben L.; Butler, Ricky W.; Caldwell, James L.

    1990-01-01

    A high-level design is presented for a reliable computing platform for real-time control applications. Design tradeoffs and analyses related to the development of the fault-tolerant computing platform are discussed. The architecture is formalized and shown to satisfy a key correctness property. The reliable computing platform uses replicated processors and majority voting to achieve fault tolerance. Under the assumption of a majority of processors working in each frame, it is shown that the replicated system computes the same results as a single processor system not subject to failures. Sufficient conditions are obtained to establish that the replicated system recovers from transient faults within a bounded amount of time. Three different voting schemes are examined and proved to satisfy the bounded recovery time conditions.

  9. The Achievement of Therapeutic Objectives Scale: Interrater Reliability and Sensitivity to Change in Short-Term Dynamic Psychotherapy and Cognitive Therapy

    ERIC Educational Resources Information Center

    Valen, Jakob; Ryum, Truls; Svartberg, Martin; Stiles, Tore C.; McCullough, Leigh

    2011-01-01

    This study examined interrater reliability and sensitivity to change of the Achievement of Therapeutic Objectives Scale (ATOS; McCullough, Larsen, et al., 2003) in short-term dynamic psychotherapy (STDP) and cognitive therapy (CT). The ATOS is a process scale originally developed to assess patients' achievements of treatment objectives in STDP,…

  10. Ceramic material life prediction: A program to translate ANSYS results to CARES/LIFE reliability analysis

    NASA Technical Reports Server (NTRS)

    Vonhermann, Pieter; Pintz, Adam

    1994-01-01

    This manual describes the use of the ANSCARES program to prepare a neutral file of FEM stress results taken from ANSYS Release 5.0, in the format needed by CARES/LIFE ceramics reliability program. It is intended for use by experienced users of ANSYS and CARES. Knowledge of compiling and linking FORTRAN programs is also required. Maximum use is made of existing routines (from other CARES interface programs and ANSYS routines) to extract the finite element results and prepare the neutral file for input to the reliability analysis. FORTRAN and machine language routines as described are used to read the ANSYS results file. Sub-element stresses are computed and written to a neutral file using FORTRAN subroutines which are nearly identical to those used in the NASCARES (MSC/NASTRAN to CARES) interface.

  11. Gearbox Reliability Collaborative Phase 1 and 2: Testing and Modeling Results; Preprint

    SciTech Connect

    Keller, J.; Guo, Y.; LaCava, W.; Link, H.; McNiff, B.

    2012-05-01

    The Gearbox Reliability Collaborative (GRC) investigates root causes of wind turbine gearbox premature failures and validates design assumptions that affect gearbox reliability using a combined testing and modeling approach. Knowledge gained from the testing and modeling of the GRC gearboxes builds an understanding of how the selected loads and events translate into internal responses of three-point mounted gearboxes. This paper presents some testing and modeling results of the GRC research during Phase 1 and 2. Non-torque loads from the rotor including shaft bending and thrust, traditionally assumed to be uncoupled with gearbox, affect gear and bearing loads and resulting gearbox responses. Bearing clearance increases bearing loads and causes cyclic loading, which could contribute to a reduced bearing life. Including flexibilities of key drivetrain subcomponents is important in order to reproduce the measured gearbox response during the tests using modeling approaches.

  12. Demands placed on waste package performance testing and modeling by some general results on reliability analysis

    SciTech Connect

    Chesnut, D.A.

    1991-09-01

    Waste packages for a US nuclear waste repository are required to provide reasonable assurance of maintaining substantially complete containment of radionuclides for 300 to 1000 years after closure. The waiting time to failure for complex failure processes affecting engineered or manufactured systems is often found to be an exponentially-distributed random variable. Assuming that this simple distribution can be used to describe the behavior of a hypothetical single barrier waste package, calculations presented in this paper show that the mean time to failure (the only parameter needed to completely specify an exponential distribution) would have to be more than 10{sub 7} years in order to provide reasonable assurance of meeting this requirement. With two independent barriers, each would need to have a mean time to failure of only 10{sup 5} years to provide the same reliability. Other examples illustrate how multiple barriers can provide a strategy for not only achieving but demonstrating regulatory compliance.

  13. The Effects of CSCOPE on Student Achievement as Measured by Both TAKS and STAAR Test Results

    ERIC Educational Resources Information Center

    Helm, Maricela Robledo

    2013-01-01

    The purpose of this study was to examine the effects of CSCOPE curriculum on student achievement. CSCOPE is a curriculum management system used in 750 of the 1,039 school districts in the state of Texas. Student achievement is based on the results acquired from the Texas Assessment of Knowledge and Skills (TAKS) and the new version of the state…

  14. Kindergarten Screening Results as Predictors of Academic Achievement, Potential, and Placement in Second Grade.

    ERIC Educational Resources Information Center

    Schmidt, Sheldon; Perino, Joseph

    1985-01-01

    Compared beginning kindergarten subtest scores on Vane Test of Language and Vane Kindergarten Test to Metropolitan Achievement Test Scores in reading and math, Otis-Lennon School Ability Test Index, and placement into special education or high achievement programs following second grade. Results revealed effective predictability of the screening…

  15. Reliability and Validity Evidence of Scores on the Achievement Goal Tendencies Questionnaire in a Sample of Spanish Students of Compulsory Secondary Education

    ERIC Educational Resources Information Center

    Ingles, Candido J.; Garcia-Fernandez, Jose M.; Castejon, Juan L.; Valle, Antonio; Delgado, Beatriz; Marzo, Juan C.

    2009-01-01

    This study examined the reliability and validity evidence drawn from the scores of the Spanish version of the Achievement Goal Tendencies Questionnaire (AGTQ) using a sample of 2,022 (51.1% boys) Spanish students from grades 7 to 10. Confirmatory factor analysis replicated the correlated three-factor structure of the AGTQ in this sample: Learning…

  16. 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.

  17. Interobserver reliability in musculoskeletal ultrasonography: results from a “Teach the Teachers” rheumatologist course

    PubMed Central

    Naredo, E; Möller, I; Moragues, C; de Agustín, J J; Scheel, A K; Grassi, W; de Miguel, E; Backhaus, M; Balint, P; Bruyn, G A W; D'Agostino, M A; Filippucci, E; Iagnocco, A; Kane, D; Koski, J M; Mayordomo, L; Schmidt, W A; Swen, W A A; Szkudlarek, M; Terslev, L; Torp‐Pedersen, S; Uson, J; Wakefield, R J; Werner, C

    2006-01-01

    Objective To assess the interobserver reliability of the main periarticular and intra‐articular ultrasonographic pathologies and to establish the principal disagreements on scanning technique and diagnostic criteria between a group of experts in musculoskeletal ultrasonography. Methods The shoulder, wrist/hand, ankle/foot, or knee of 24 patients with rheumatic diseases were evaluated by 23 musculoskeletal ultrasound experts from different European countries randomly assigned to six groups. The participants did not reach consensus on scanning method or diagnostic criteria before the investigation. They were unaware of the patients' clinical and imaging data. The experts from each group undertook a blinded ultrasound examination of the four anatomical regions. The ultrasound investigation included the presence/absence of joint effusion/synovitis, bony cortex abnormalities, tenosynovitis, tendon lesions, bursitis, and power Doppler signal. Afterwards they compared the ultrasound findings and re‐examined the patients together while discussing their results. Results Overall agreements were 91% for joint effusion/synovitis and tendon lesions, 87% for cortical abnormalities, 84% for tenosynovitis, 83.5% for bursitis, and 83% for power Doppler signal; κ values were good for the wrist/hand and knee (0.61 and 0.60) and fair for the shoulder and ankle/foot (0.50 and 0.54). The principal differences in scanning method and diagnostic criteria between experts were related to dynamic examination, definition of tendon lesions, and pathological v physiological fluid within joints, tendon sheaths, and bursae. Conclusions Musculoskeletal ultrasound has a moderate to good interobserver reliability. Further consensus on standardisation of scanning technique and diagnostic criteria is necessary to improve musculoskeletal ultrasonography reproducibility. PMID:15941835

  18. WEF/WERF study of BNR plants achieving very low N and P limits: evaluation of technology performance and process reliability.

    PubMed

    Bott, Charles B; Parker, Denny S; Jimenez, Jose; Miller, Mark W; Neethling, J B

    2012-01-01

    The Water Environment Research Foundation (WERF) funded a two-year comprehensive study of nutrient removal plants designed and operated to meet very low effluent total nitrogen (TN) and total phosphorus (TP) concentrations. WERF worked with the Water Environment Federation (WEF) to solicit participation of volunteers and provide a forum for information exchange at workshops at its annual conferences. Both existing and new technologies are being adapted to meet requirements that are as low as 3.0 mg/L TN and 0.1 mg/L TP, and there is a need to define their capabilities and reliabilities in the real world situation of wastewater treatment plants. A concern over very low daily permits for ammonia caused the work to be extended to include nitrification reliability. This effort focused on maximizing what can be learned from existing technologies in order to provide a database that will inform key decision makers about proper choices for both technologies and rationale bases for statistical permit writing. To this end, managers of 22 plants, 10 achieving low effluent TP, nine achieving low effluent TN, and three achieving low effluent NH(3)-N, provided three years of operational data that were analyzed using a consistent statistical approach. Technology Performance Statistics (TPSs) were developed as three separate values representing the ideal, median, and reliably achievable performance. Technological conclusions can be drawn from the study in terms of what can be learned by comparing the different nutrient removal and nitrification processes employed at these 22 plants.

  19. Reliability of environmental sampling culture results using the negative binomial intraclass correlation coefficient.

    PubMed

    Aly, Sharif S; Zhao, Jianyang; Li, Ben; Jiang, Jiming

    2014-01-01

    The Intraclass Correlation Coefficient (ICC) is commonly used to estimate the similarity between quantitative measures obtained from different sources. Overdispersed data is traditionally transformed so that linear mixed model (LMM) based ICC can be estimated. A common transformation used is the natural logarithm. The reliability of environmental sampling of fecal slurry on freestall pens has been estimated for Mycobacterium avium subsp. paratuberculosis using the natural logarithm transformed culture results. Recently, the negative binomial ICC was defined based on a generalized linear mixed model for negative binomial distributed data. The current study reports on the negative binomial ICC estimate which includes fixed effects using culture results of environmental samples. Simulations using a wide variety of inputs and negative binomial distribution parameters (r; p) showed better performance of the new negative binomial ICC compared to the ICC based on LMM even when negative binomial data was logarithm, and square root transformed. A second comparison that targeted a wider range of ICC values showed that the mean of estimated ICC closely approximated the true ICC.

  20. A novel approach to obtaining reliable PCR results from luminol treated bloodstains.

    PubMed

    Della Manna, A; Montpetit, S

    2000-07-01

    In recent years the forensic scientist has been afforded great advances in technology both in the detection of latent bloodstains and in acquiring reliable DNA typing results from very small pieces of physical evidence. Scientists are now able to detect minute quantities of latent bloodstains by utilizing the luminol reagent, oftentimes indicating that an attempt has been made to conceal any evidence of bloodshed. With the introduction of PCR based technology to the forensic arena, scientists are now routinely able to obtain DNA typing results from previously insufficient amounts of biological material, items as small as a single hair, saliva on a cigarette butt, or a bloodstain the size of a pin head. We present here a merging of these two advances coupled with a new collection medium for post luminol treated latent bloodstains. The forensic scientist is now able to routinely isolate and recover an adequate amount of DNA suitable for PCR typing at all of the Promega GenePrint PowerPlex 1.1 loci. In this study, several dilutions of latent bloodstains were prepared in an effort to simulate transferred bloodstains that are routinely encountered in a crime scene setting. The latent bloodstains were treated with luminol and subsequently collected using conventional cotton tipped swabs as well as a Puritan sponge tipped swab. PCR typing at the Promega GenePrint PowerPlex 1.1 loci was then attempted upon all dilutions of the latent bloodstains for both collection mediums. The results clearly indicate that it is now routinely possible to recover adequate amounts of DNA suitable for PCR typing upon post luminol treated bloodstains.

  1. A limited assessment of the ASEP human reliability analysis procedure using simulator examination results

    SciTech Connect

    Gore, B.R.; Dukelow, J.S. Jr.; Mitts, T.M.; Nicholson, W.L.

    1995-10-01

    This report presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR-4772. In particular, the, ASEP post-accident, post-diagnosis, nominal HRA procedure is assessed within the context of an individual`s performance of critical tasks on the simulator portion of requalification examinations administered to nuclear power plant operators. An assessment of the degree to which operator perforn:Lance during simulator examinations is an accurate reflection of operator performance during actual accident conditions was outside the scope of work for this project; therefore, no direct inference can be made from this report about such performance. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle. A total of 4071 critical tasks were identified, of which 45 had been failed. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. ASEP analyses were performed for a sample of 162 critical tasks selected randomly from the 4071, and the results were used to characterize the entire population. ASEP analyses were also performed for all of the 45 failed critical tasks. Two tests were performed to assess the bias of the ASEP HEPs compared with the data from the requalification examinations. The first compared the average of the ASEP HEP values with the fraction of the population actually failed and it found a statistically significant factor of two bias on the average.

  2. Temperature and vibration results from captive-store flight tests provide a reliability improvement tool

    NASA Astrophysics Data System (ADS)

    Calatayud, Richard; Szymkowiak, Edward A.

    The ALQ-131 electronic countermeasure (ECM) system has provided the United States Air Force with proven self-protection for many of its tactical fighter aircraft. The reliability and maintainability (R&M) improvements of the ALQ-131 Block II has produced a system with an mean time between failures (MTBF) of 120 to 180 h and greater than 95 percent availability for the 390 systems in theater during the Persian Gulf war. Classic R&M approaches have gotten the ALQ-131 to this high standard, but improved understanding of the environment experienced by the system will provide the next steps in reliability improvements. The capture of measured response data will provide a basis for development life cycle and customer warranty tests which will guarantee to the customer that the ALQ-131 system will continue to perform reliably from takeoff to landing and from mission to mission through the life of the system.

  3. Next Generation Scientists, Next Opportunities: EPA's Science To Achieve Results (STAR) Program

    NASA Astrophysics Data System (ADS)

    Jones, M.

    2004-12-01

    Scientific research is one of the most powerful tools we have for understanding and protecting our environment. It provides the foundation for what we know about our planet, how it has changed, and how it could be altered in the future. The National Center for Environmental Research (NCER) in the U.S. Environmental Protection Agency's (EPA) Office of Research and Development (ORD) supports high-quality, extramural research by the nation's leading scientists and engineers to strengthen the basis for decisions about local and national environmental issues. NCER works with academia, state and local governments, other federal agencies, and scientists in EPA to increase human knowledge of how to protect our health and natural resources through its three major programs: · Science to Achieve Results (STAR) Grants · Small Business Innovative Research (SBIR) · Science to Achieve Results (STAR) Fellowships STAR, NCER's primary program, funds research grants and graduate fellowships in environmental science and engineering. Developing the next generation of environmental scientists and engineers is one of NCER's most important objectives. Each year, NCER helps between 80 and 160 students achieve Master's or Ph.D. degrees in environmental science and engineering through its STAR and Greater Research Opportunities (GRO) fellowships. Some of these students have moved on to careers in government while others are now full-time professors and researchers. Still others are working for state environmental agencies or furthering their studies through postdoctoral positions at universities. Since the inception of the NCER program, STAR fellowships (along with grants and SBIR projects) have been awarded in every state in the country. With the help of STAR, current and future scientists and engineers have been able to explore ways to preserve and protect human health and our precious resources.

  4. The European COPHES/DEMOCOPHES project: towards transnational comparability and reliability of human biomonitoring results.

    PubMed

    Schindler, Birgit Karin; Esteban, Marta; Koch, Holger Martin; Castano, Argelia; Koslitz, Stephan; Cañas, Ana; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Schwedler, Gerda; Schoeters, Greet; Hond, Elly Den; Sepai, Ovnair; Exley, Karen; Bloemen, Louis; Horvat, Milena; Knudsen, Lisbeth E; Joas, Anke; Joas, Reinhard; Biot, Pierre; Aerts, Dominique; Lopez, Ana; Huetos, Olga; Katsonouri, Andromachi; Maurer-Chronakis, Katja; Kasparova, Lucie; Vrbík, Karel; Rudnai, Peter; Naray, Miklos; Guignard, Cedric; Fischer, Marc E; Ligocka, Danuta; Janasik, Beata; Reis, M Fátima; Namorado, Sónia; Pop, Cristian; Dumitrascu, Irina; Halzlova, Katarina; Fabianova, Eleonora; Mazej, Darja; Tratnik, Janja Snoj; Berglund, Marika; Jönsson, Bo; Lehmann, Andrea; Crettaz, Pierre; Frederiksen, Hanne; Nielsen, Flemming; McGrath, Helena; Nesbitt, Ian; De Cremer, Koen; Vanermen, Guido; Koppen, Gudrun; Wilhelm, Michael; Becker, Kerstin; Angerer, Jürgen

    2014-07-01

    between 18.9 and 45.3% for the phthalate metabolites. Plausibility control of the HBM results of all participating countries disclosed analytical shortcomings in the determination of Cd when using certain ICP/MS methods. Results were corrected by reanalyzes. The COPHES/DEMOCOPHES project for the first time succeeded in performing a harmonized pan-European HBM project. All data raised have to be regarded as utmost reliable according to the highest international state of the art, since highly renowned laboratories functioned as reference laboratories. The procedure described here, that has shown its success, can be used as a blueprint for future transnational, multicentre HBM projects.

  5. The Reliability of Results from National Tests, Public Examinations, and Vocational Qualifications in England

    ERIC Educational Resources Information Center

    He, Qingping; Opposs, Dennis

    2012-01-01

    National tests, public examinations, and vocational qualifications in England are used for a variety of purposes, including the certification of individual learners in different subject areas and the accountability of individual professionals and institutions. However, there has been ongoing debate about the reliability and validity of their…

  6. Validity and Reliability of Turkish Version of Gilliam Autism Rating Scale-2: Results of Preliminary Study

    ERIC Educational Resources Information Center

    Diken, Ibrahim H.; Diken, Ozlem; Gilliam, James E.; Ardic, Avsar; Sweeney, Dwight

    2012-01-01

    The purpose of this preliminary study was to explore the validity and reliability of Turkish Version of the Gilliam Autism Rating Scale-2 (TV-GARS-2). Participants included 436 children diagnosed with autism (331 male and 105 female, mean of ages was 8.01 with SD = 3.77). Data were also collected from individuals diagnosed with intellectual…

  7. Interrater Reliability of the Outcomes and Assessment Information Set: Results from the Field.

    ERIC Educational Resources Information Center

    Madigan, Elizabeth A.; Fortinsky, Richard H.

    2004-01-01

    The Outcomes and Assessment Information Set (OASIS) is now used extensively for regulatory, reimbursement, research, and clinical purposes in home health care. However, little is known about the interrater reliability of OASIS items based on assessments from home-health-agency clinicians. Therefore, we evaluated OASIS item interrater reliability…

  8. Automated Energy Distribution and Reliability System: Validation Integration - Results of Future Architecture Implementation

    SciTech Connect

    Buche, D. L.

    2008-06-01

    This report describes Northern Indiana Public Service Co. project efforts to develop an automated energy distribution and reliability system. The purpose of this project was to implement a database-driven GIS solution that would manage all of the company's gas, electric, and landbase objects. This report is second in a series of reports detailing this effort.

  9. Reliability Analysis of Large Commercial Vessel Engine Room Automation Systems. Volume 1. Results

    DTIC Science & Technology

    1982-11-01

    8217 parameters drifting or calibration problems, and only require adjustment. B. FAILURE MODES AND EFFECTS ANALYSIS. The FMEAs revealed conditions that...reliability analysis included relia- bility predictions, failure modes and effects analyses ( FMEA ), criticality analysis, and fault tree analyses. For...safety hazards. In order to better evaluate the effects of failures, Failure Modes and Effects Analysis ( FMEA ), Criticality Analysis and Fault Tree

  10. Durability of bleaching results achieved with 15% carbamide peroxide and 38% hydrogen peroxide in vitro.

    PubMed

    Knösel, Michael; Reus, Monika; Rosenberger, Albert; Attin, Thomas; Ziebolz, Dirk

    2011-01-01

    The aim of this study was to assess the durability of bleaching results achieved with (1) 15% carbamide peroxide home bleaching and (2) 38% hydrogen peroxide in-office bleaching. A total of 231 extracted anterior teeth were randomly divided into three groups (n = 77 in each group) with comparable mean baseline L*-values (68.24 ± 0.8): a non-bleached control group A, a 15% carbamide peroxide group B (5 bleaching intervals of 8 hours), and a 38% hydrogen peroxide group C (3 intervals of 15 minutes). Durability of bleaching was assessed by comparing CIE-L*a*b* data after intervals of 2, 4, 12, and 26 weeks from baseline. Both bleaching regimes initially produced a highly significant increase in lightness parameter L*, with no significant difference between the respective bleaching regimes (B: 68.23 / 72.48; C: 68.32 / 73.25). Six months after starting the trial, L*-values for group B yielded no significant differences compared to baseline (69.55), whereas L*-values for group C were still significantly raised (69.91), despite a highly significant decrease when compared to initial bleaching results. In both treatment groups, there was a lasting response to bleaching in terms of CIE-a* and -b* value decreases. Results for both home- and in-practice regimes were found to be similar for about 12 weeks. However, in-office results were longer lasting, despite the shorter treatment intervals. Summarized bleaching effects, in terms of delta E values, revealed no significant differences between treatment groups and the control group after 6 months, indicating an abatement of the bleaching results achieved.

  11. Multimodal treatment of unresectable hepatocellular carcinoma to achieve complete response results in improved survival

    PubMed Central

    Newell, Pippa H; Wu, YingXing; Hoen, Helena; Uppal, Richa; Thiesing, John Tyler; Sasadeusz, Kevin; Cassera, Maria A; Wolf, Ronald F; Hansen, Paul; Hammill, Chet W

    2015-01-01

    Introduction With technological advances, questions arise regarding how to best fit newer treatment modalities, such as transarterial therapies, into the treatment algorithm for patients with hepatocellular carcinoma (HCC). Methods Between 2005 and 2011, 128 patients initially treated with transarterial radioembolization or chemoembolization using drug-eluting beads were identified. The response was graded retrospectively. Toxicity was measured 1, 3, and 6 months after the first and last treatments. Results Sixty-five patients (53%) were advanced stage. Twenty patients (16%) had an initial complete response, but with additional treatments, this was increased to 46 (36%). Patients with a complete response as their best response to treatment had a median survival [95% confidence interval (CI)] of 5.77 (2.58, upper limit not yet reached) years, significantly longer than those whose best response was a partial response, 1.22 (0.84, 2.06) years and those with stable disease as their best response, 0.34 (0.29, 0.67) years. Repeated treatments did not increase toxicity. Discussion This retrospective review of patients treated for intermediate and advanced stage HCC revealed a significant survival advantage in patients who achieved a complete response. These data support use of a multi-modality approach to intermediate and advanced stage HCC, combining liver-directed treatments as necessary to achieve a complete response. PMID:25580988

  12. Results from D-T Experiments on TFTR and Implications for Achieving an Ignited Plasma

    SciTech Connect

    Hawryluk, R.J. and the TFTR Group

    1998-07-14

    Progress in the performance of tokamak devices has enabled not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain for achieving a magnetic fusion energy reactor. In this paper, the implications of the TFTR experiments for overcoming these remaining issues will be discussed.

  13. [A systematic social observation tool: methods and results of inter-rater reliability].

    PubMed

    Freitas, Eulilian Dias de; Camargos, Vitor Passos; Xavier, César Coelho; Caiaffa, Waleska Teixeira; Proietti, Fernando Augusto

    2013-10-01

    Systematic social observation has been used as a health research methodology for collecting information from the neighborhood physical and social environment. The objectives of this article were to describe the operationalization of direct observation of the physical and social environment in urban areas and to evaluate the instrument's reliability. The systematic social observation instrument was designed to collect information in several domains. A total of 1,306 street segments belonging to 149 different neighborhoods in Belo Horizonte, Minas Gerais, Brazil, were observed. For the reliability study, 149 segments (1 per neighborhood) were re-audited, and Fleiss kappa was used to access inter-rater agreement. Mean agreement was 0.57 (SD = 0.24); 53% had substantial or almost perfect agreement, and 20.4%, moderate agreement. The instrument appears to be appropriate for observing neighborhood characteristics that are not time-dependent, especially urban services, property characterization, pedestrian environment, and security.

  14. Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Cold Climates

    SciTech Connect

    Building Industry Research Alliance; Building Science Consortium; Consortium for Advanced Residential Buildings; Florida Solar Energy Center; IBACOS; National Renewable Energy Laboratory

    2006-08-01

    The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in Cold Climates on a cost-neutral basis.

  15. Taking advantage of ground data systems attributes to achieve quality results in testing software

    NASA Technical Reports Server (NTRS)

    Sigman, Clayton B.; Koslosky, John T.; Hageman, Barbara H.

    1994-01-01

    During the software development life cycle process, basic testing starts with the development team. At the end of the development process, an acceptance test is performed for the user to ensure that the deliverable is acceptable. Ideally, the delivery is an operational product with zero defects. However, the goal of zero defects is normally not achieved but is successful to various degrees. With the emphasis on building low cost ground support systems while maintaining a quality product, a key element in the test process is simulator capability. This paper reviews the Transportable Payload Operations Control Center (TPOCC) Advanced Spacecraft Simulator (TASS) test tool that is used in the acceptance test process for unmanned satellite operations control centers. The TASS is designed to support the development, test and operational environments of the Goddard Space Flight Center (GSFC) operations control centers. The TASS uses the same basic architecture as the operations control center. This architecture is characterized by its use of distributed processing, industry standards, commercial off-the-shelf (COTS) hardware and software components, and reusable software. The TASS uses much of the same TPOCC architecture and reusable software that the operations control center developer uses. The TASS also makes use of reusable simulator software in the mission specific versions of the TASS. Very little new software needs to be developed, mainly mission specific telemetry communication and command processing software. By taking advantage of the ground data system attributes, successful software reuse for operational systems provides the opportunity to extend the reuse concept into the test area. Consistency in test approach is a major step in achieving quality results.

  16. First Year Results of the Student Achievement Guarantee in Education Program. Executive Summary.

    ERIC Educational Resources Information Center

    Maier, Peter; Molnar, Alex; Percy, Stephen; Smith, Phillip; Zahorik, John

    The Student Achievement Guarantee in Education (SAGE) program is a statewide effort in Wisconsin to increase the academic achievement of children living in poverty by eventually reducing the student-teacher ratio in kindergarten through grade 3 to 15:1. During 1995-1996, the Sage program was implemented in 30 schools in 21 school districts. Over…

  17. Achievement Goal Validation among African American High School Students: CFA and Rasch Results

    ERIC Educational Resources Information Center

    Hart, Caroline O.; Mueller, Christian E.; Royal, Kenneth D.; Jones, Martin H.

    2013-01-01

    Achievement goal theory helps describe how and why students engage in various academic behaviors. Historically, achievement goals have been examined almost exclusively with undergraduate, nonminority samples, and predominately with factor analytic techniques. The present study adds to a growing literature by providing initial validation of a…

  18. Evaluation Results of the Student Achievement Guarantee in Education (SAGE) Program, 1998-99.

    ERIC Educational Resources Information Center

    Molnar, Alex; Smith, Philip; Zahorik, John

    The Student Achievement Guarantee in Education (SAGE) is a statewide effort in Wisconsin to increase the academic achievement of children living in poverty by reducing the student-teacher ratio in kindergarten through third grade to 15:1. Schools participating in SAGE are also required to implement a rigorous curriculum, provide before- and…

  19. Testing the Reliability of Manual Mapping of Glacial Landforms: Initial Results

    NASA Astrophysics Data System (ADS)

    Hillier, John K.; Smith, Mike J.

    2015-04-01

    Mapped topographic features are important for understanding processes that sculpt the Earth's surface. Manual, interpretive, techniques for mapping are commonly used yet, it is difficult to assess their effectiveness. Here 'real' DEMs are modified by inserting 'synthetic' drumlins in to them [Hillier and Smith, 2012] for mappers to identify. Interactive maps are presented that display 12,121 outlines drawn by 25 interpreters searching for a total of 21,625 drumlins. Overall detection rates (i.e. ncoincident/ntotal) are low at 34-40%, interestingly comparable to automated methods [Eisank et al., 2014], but reliability (i.e. ncoincident/nmapped) is higher at 72-86%. A pilot study also indicates that drumlin height is the key dimension driving detectability, with rates decreasing from 100% to

  20. Younger poor ovarian response women achieved better pregnancy results in the first three IVF cycles.

    PubMed

    Yang, Yajuan; Sun, Xiuhua; Cui, Linlin; Sheng, Yan; Tang, Rong; Wei, Daimin; Qin, Yingying; Li, Weiping; Chen, Zi-Jiang

    2016-05-01

    This retrospective cohort study observed the live birth rates as well as cumulative live birth rates in women with poor ovarian response (POR) undergoing IVF-embryo transfer treatment, stratified for age and cycle number. Four hundred and one patients with POR diagnosed according to the Bologna criteria were enrolled and 700 IVF-ET cycles were analysed. The overall live-birth rate per cycle was 18.3%. From cycle 1 up to cycle 3, the live-birth rates decreased significantly from 22.2% to 11.1%. The live-birth rate fell to 2.4% in cycles 4 and over. When age advanced, the live birth rates decreased obviously (P < 0.01): 30.0% for women < 35 years old, 17.0% for those 35-40 years old, and 9.0% for women older than 40 years. Similarly, the cumulative live birth rates dropped from 48.0% (< 35 years) to 16.9% (≥ 40 years) accordingly. Younger patients (< 35 years old) with POR achieved better pregnancy results compared with patients of advanced age. Extremely low live-birth rates could be anticipated after three unsuccessful cycles; therefore it may not be appropriate to suggest more IVF cycles in POR women.

  1. Life insurance and genetic test results: a mutation carrier's fight to achieve full cover.

    PubMed

    Keogh, Louise A; Otlowski, Margaret F A

    2013-09-02

    Currently, there is debate about life insurance companies' use of genetic information for assessing applicants. In his early 20s, James (pseudonym) was denied full life insurance cover because he revealed that he had discussed genetic testing with a genetic counsellor. He was later tested and found to carry a mutation in the MSH6 gene; after disclosing this, he was denied cover for cancer by two other life insurance companies. Unsatisfied with the insurance companies' risk assessments, and based on his understanding that regular colonoscopy significantly reduced his risk of cancer, James made a complaint to the Australian Human Rights Commission. After informing the third insurance company that he had done so, he was offered full coverage, which suggests that the company did not have actuarial data to justify its decision. This case provides evidence of the high level of initiative and proactivity required for a consumer to achieve a fair result. Few Australians would be in a position to pursue the level of research and advocacy undertaken by James (a professional with scientific training). We call on a collaborative approach between industry, government and researchers to address the issues that James's case raises about genetic testing and life insurance.

  2. Results from D-T experiments on TFTR and implications for achieving an ignited plasma

    SciTech Connect

    Hawryluk, R.J.; Blanchard, W.; Batha, S.

    1998-07-01

    Progress in the performance of tokamak devices has enable not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain. In this paper, the implications for the TFTR experiments for overcoming these remaining issues will be discussed.

  3. Mathematics beliefs and achievement of adolescent students in Japan: results from the TIMSS 1999 assessment.

    PubMed

    House, J Daniel

    2005-12-01

    A recent study (1) of undergraduate students in a precalculus course indicated that they expressed slightly positive attitudes toward mathematics. It is important, however, to examine relationships between students' initial attitudes and achievement outcomes. The present purpose was to assess the relationship between self-beliefs and mathematics achievement for a large national sample of students from the TIMSS 1999 international sample (eighth graders) from Japan. Several significant relationships between mathematics beliefs and test scores were noted. In addition, the overall multiple regression equation that assessed the joint significance of the complete set of self-belief variables was significant (F7.65 = 159.48, p < .001) and explained 20.6% of the variance in mathematics achievement test scores.

  4. Minnesota Developmental Achievement Centers: 1987 Survey Results. Policy Analysis Series, No. 28.

    ERIC Educational Resources Information Center

    Minnesota Governor's Planning Council on Developmental Disabilities, St. Paul.

    This paper presents data collected from rehabilitation centers serving individuals with developmental disabilities in Minnesota, called Developmental Achievement Centers (DACs). The data focus on finances, programs, and clients, and are compared with data from previous years. All 97 providers of adult services in Minnesota completed the survey,…

  5. Improving Achievement in Low-Performing Schools: Key Results for School Leaders

    ERIC Educational Resources Information Center

    Ward, Randolph E.; Burke, Mary Ann

    2004-01-01

    As accountability in schools becomes more crucial, educators are looking for comprehensive and innovative management practices that respond to challenges and realities of student academic achievement. In order to improve academic performance and the quality of instruction, the entire school community needs to be involved. This book provides six…

  6. School Climate, Peer Victimization, and Academic Achievement: Results from a Multi-Informant Study

    ERIC Educational Resources Information Center

    Wang, Weijun; Vaillancourt, Tracy; Brittain, Heather L.; McDougall, Patricia; Krygsman, Amanda; Smith, David; Cunningham, Charles E.; Haltigan, J. D.; Hymel, Shelley

    2014-01-01

    School-level school climate was examined in relation to self-reported peer victimization and teacher-rated academic achievement (grade point average; GPA). Participants included a sample of 1,023 fifth-grade children nested within 50 schools. Associations between peer victimization, school climate, and GPA were examined using multilevel modeling,…

  7. Connecting Mentoring to Student Achievement in Alaska: Results and Policy Implications

    ERIC Educational Resources Information Center

    Adams, Barbara L.

    2010-01-01

    Using hierarchical linear modeling, student standardized test scores are analyzed to determine the impact of mentoring first- and second-year teachers on their students' achievement. The contrasting group used for comparison consists of experienced teachers in matched schools, grade level, and content area. The study contains data from 300…

  8. Reading Achievement and Social Selection in Independent Schools in Sweden: Results from IEA PIRLS 2001

    ERIC Educational Resources Information Center

    Myrberg, Eva; Rosen, Monica

    2006-01-01

    The study investigates the mean difference in reading achievement between third-graders in public and independent schools in Sweden. The data come from the Swedish participation in PIRLS 2001 conducted by IEA. Variables from the home questionnaire mainly indicating possession of cultural capital are used as independent variables. A total IRT score…

  9. Some Results and Comments on Using Latent Structure Models to Measure Achievement.

    ERIC Educational Resources Information Center

    Wilcox, Rand R.

    1980-01-01

    Technical problems in achievement testing associated with using latent structure models to estimate the probability of guessing correct responses by examinees is studied; also the lack of problems associated with using Wilcox's formula score. Maximum likelihood estimates are derived which may be applied when items are hierarchically related.…

  10. Student Achievement in Edison Schools: Mixed Results in an Ongoing Enterprise. Research Report.

    ERIC Educational Resources Information Center

    American Federation of Teachers, Washington, DC.

    A study examined student achievement in selected Edison schools through an analysis of test-score data. To qualify for the study, each school had to be in operation for more than 1 year and had to have solid student testing data from a solid evaluation design. Eight schools were selected, and their reading data were compared with those of…

  11. Field-Induced Crystalline-to-Amorphous Phase Transformation on the Si Nano-Apex and the Achieving of Highly Reliable Si Nano-Cathodes

    PubMed Central

    Huang, Yifeng; Deng, Zexiang; Wang, Weiliang; Liang, Chaolun; She, Juncong; Deng, Shaozhi; Xu, Ningsheng

    2015-01-01

    Nano-scale vacuum channel transistors possess merits of higher cutoff frequency and greater gain power as compared with the conventional solid-state transistors. The improvement in cathode reliability is one of the major challenges to obtain high performance vacuum channel transistors. We report the experimental findings and the physical insight into the field induced crystalline-to-amorphous phase transformation on the surface of the Si nano-cathode. The crystalline Si tip apex deformed to amorphous structure at a low macroscopic field (0.6~1.65 V/nm) with an ultra-low emission current (1~10 pA). First-principle calculation suggests that the strong electrostatic force exerting on the electrons in the surface lattices would take the account for the field-induced atomic migration that result in an amorphization. The arsenic-dopant in the Si surface lattice would increase the inner stress as well as the electron density, leading to a lower amorphization field. Highly reliable Si nano-cathodes were obtained by employing diamond like carbon coating to enhance the electron emission and thus decrease the surface charge accumulation. The findings are crucial for developing highly reliable Si-based nano-scale vacuum channel transistors and have the significance for future Si nano-electronic devices with narrow separation. PMID:25994377

  12. Mathematics Instruction and Achievement of Eighth-Grade Students in Korea: Results from the TIMSS 2007 Assessment

    ERIC Educational Resources Information Center

    House, J, Daniel; Telese, James A.

    2013-01-01

    Effective teaching practice for improving student achievement in mathematics is a critical area for instructional design. Further, results from international assessments of mathematics achievement have indicated that students in Korea typically earned test scores higher then international averages. The purpose of this study was to investigate the…

  13. Problems of a thermionic space NPS reactor unit quantitative reliability assessment on the basis of ground development results

    SciTech Connect

    Ponomarev-Stepnoi, Nikolai N.; Nechaev, Yuri A.; Khazanovich, Igor M.; Samodelov, Victor N.; Pavlov, Konstantin A.

    1997-01-10

    The paper sets forth major problems that arose in the course of a quantitative assessment of reliability of a TOPAZ-2 space NPS reactor unit performed on the basis of ground development results. Proposals are made on the possible ways to solve those problems through development and introduction of individual standards especially for the ground development stage, which would specify the assessment algorithm and censoring rules, and exclude a number of existing uncertainties when making a decision on going to flight testing.

  14. Measurement and computer simulation of antennas on ships and aircraft for results of operational reliability

    NASA Astrophysics Data System (ADS)

    Kubina, Stanley J.

    1989-09-01

    The review of the status of computational electromagnetics by Miller and the exposition by Burke of the developments in one of the more important computer codes in the application of the electric field integral equation method, the Numerical Electromagnetic Code (NEC), coupled with Molinet's summary of progress in techniques based on the Geometrical Theory of Diffraction (GTD), provide a clear perspective on the maturity of the modern discipline of computational electromagnetics and its potential. Audone's exposition of the application to the computation of Radar Scattering Cross-section (RCS) is an indication of the breadth of practical applications and his exploitation of modern near-field measurement techniques reminds one of progress in the measurement discipline which is essential to the validation or calibration of computational modeling methodology when applied to complex structures such as aircraft and ships. The latter monograph also presents some comparison results with computational models. Some of the results presented for scale model and flight measurements show some serious disagreements in the lobe structure which would require some detailed examination. This also applies to the radiation patterns obtained by flight measurement compared with those obtained using wire-grid models and integral equation modeling methods. In the examples which follow, an attempt is made to match measurements results completely over the entire 2 to 30 MHz HF range for antennas on a large patrol aircraft. The problem of validating computer models of HF antennas on a helicopter and using computer models to generate radiation pattern information which cannot be obtained by measurements are discussed. The use of NEC computer models to analyze top-side ship configurations where measurement results are not available and only self-validation measures are available or at best comparisons with an alternate GTD computer modeling technique is also discussed.

  15. Reliability training

    NASA Technical Reports Server (NTRS)

    Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Dillard, Richard B.; Wong, Kam L.; Barber, Frank J.; Barina, Frank J.

    1992-01-01

    Discussed here is failure physics, the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low cost reliable products. A review of reliability for the years 1940 to 2000 is given. Next, a review of mathematics is given as well as a description of what elements contribute to product failures. Basic reliability theory and the disciplines that allow us to control and eliminate failures are elucidated.

  16. Problems of a thermionic space NPS reactor unit quantitative reliability assessment on the basis of ground development results

    SciTech Connect

    Ponomarev-Stepnoi, N.N.; Nechaev, Y.A.; Khazanovich, I.M.; Samodelov, V.N.; Pavlov, K.A.

    1997-01-01

    The paper sets forth major problems that arose in the course of a quantitative assessment of reliability of a TOPAZ-2 space NPS reactor unit performed on the basis of ground development results. Proposals are made on the possible ways to solve those problems through development and introduction of individual standards especially for the ground development stage, which would specify the assessment algorithm and censoring rules, and exclude a number of existing uncertainties when making a decision on going to flight testing. {copyright} {ital 1997 American Institute of Physics.}

  17. Are New Technologies Influencing the Academic Results Achieved by Students? An Exploratory Study

    ERIC Educational Resources Information Center

    Gargallo-Castel, Ana; Esteban-Salvador, Luisa; Marzo-Navarro, Mercedes

    2010-01-01

    The purpose of this study is to analyze the application of Information Communication Technologies (ICTs) within tertiary education in a Spanish University. We analyze the results of a new initiative developed by the University of Zaragoza through an innovative project for a virtual campus called "Anillo Digital Docente." Data relating to…

  18. Is the Presence of a Results-Oriented Professional Learning Community Predictive of Student Achievement?

    ERIC Educational Resources Information Center

    Sullivan, Michael E.

    2013-01-01

    This study investigated the relationships between teacher collaboration practices known as working as a professional learning community (PLC) and student performance. Through a review of the current literature, an operational framework of PLCs was developed that distinguished results-oriented from inquiry-oriented PLCs. The study considered the…

  19. So What's Different? Student Achievement and Attitude Results from Instructional Development Projects.

    ERIC Educational Resources Information Center

    Eastmond, J. Nicholls; Van Horn, Kathleen L.

    Reported are the results of instructional development projects at Utah State University, funded under mini grants, faculty development grants, or developmental grants to departments. These projects involve redesign of courses in media production, library resources, pattern design and fitting, counselling psychology, quantitative methods,…

  20. "STEPS" Avionics for Exploration Systems the Achieved Results and the Next "STEPS-2"

    NASA Astrophysics Data System (ADS)

    Martelli, Andrea; Perino, Maria Antonietta; Gaia, Enrico; Paccagnini, Carlo

    2013-08-01

    This paper presents the STEPS project reached results in the avionics domains like: vision-based GNC for Mars Descent & Landing, Hazard avoidance and complete spacecraft autonomy; Autonomous Rover Navigation, based on perception, 3D map reconstruction and path planning; Mobility & Mechanisms providing an Integrated Ground Mobility System, Rendezvous & Docking equipment, and protection from Environment effects; Human-machine interface features of a predictive Command and Control System;; novel Design & Development Tools, such as a Rover S/W simulator and prototypes of the DEM viewer and of a S/W Rock Creator/visualizator. This paper presents also the STEPS 2 project that started January 2013 and is aimed at improving the development of the most promising technologies, selected from the results of the first STEP phase, and addressing the needs of the exploration missions as defined in the 2012 ministerial conference, with the ultimate goal of an in-flight validation within next five years.

  1. Biosocial Influences on Sex Differences for Ability and Achievement Test Results as Well as Marks at School.

    ERIC Educational Resources Information Center

    Fischbein, Siv

    1990-01-01

    A comparison was made of ability and achievement test results and school grades for 323 pairs of Swedish male and female twins and 740 controls in relation to social background. An interaction effect of sex and social background was found for verbal ability and mathematics test results. (SLD)

  2. Electrical machines with bulk HTS elements.. The achieved results and future development

    NASA Astrophysics Data System (ADS)

    Kovalev, L. K.; Ilushin, K. V.; Penkin, V. T.; Kovalev, K. L.; Koneev, S. M.-A.; Modestov, K. A.; Larionoff, S. A.; Gawalek, W.; Oswald, B.

    2001-09-01

    Novel types of electric HTS motors with the rotor containing bulk YBCO and Bi-Ag elements are presented. Different schematics of hysteresis, reluctance “trapped field” and composed HTS motors are discussed. Two-dimensional mathematical models describing the processes in these types of HTS machines were developed on the basis of a theoretical analysis of the electrodynamic and hysteresis processes in multi-domain and single-domain HTS ceramic samples. The test results of these HTS motors with output power 1-37 kW and current frequencies 50 and 400 Hz are given. The results show that in liquid nitrogen the specific output power per one weight unit is 4-5 times better then for conventional electric machines. The design of a new high power HTS motor operating in the liquid nitrogen with output power 200 kW (and more) is discussed. Future applications of new types of HTS motors for airspace and on-land industry and transport systems are discussed.

  3. The extent of food waste generation across EU-27: different calculation methods and the reliability of their results.

    PubMed

    Bräutigam, Klaus-Rainer; Jörissen, Juliane; Priefer, Carmen

    2014-08-01

    The reduction of food waste is seen as an important societal issue with considerable ethical, ecological and economic implications. The European Commission aims at cutting down food waste to one-half by 2020. However, implementing effective prevention measures requires knowledge of the reasons and the scale of food waste generation along the food supply chain. The available data basis for Europe is very heterogeneous and doubts about its reliability are legitimate. This mini-review gives an overview of available data on food waste generation in EU-27 and discusses their reliability against the results of own model calculations. These calculations are based on a methodology developed on behalf of the Food and Agriculture Organization of the United Nations and provide data on food waste generation for each of the EU-27 member states, broken down to the individual stages of the food chain and differentiated by product groups. The analysis shows that the results differ significantly, depending on the data sources chosen and the assumptions made. Further research is much needed in order to improve the data stock, which builds the basis for the monitoring and management of food waste.

  4. Waste Minimization Improvements Achieved Through Six Sigma Analysis Result In Significant Cost Savings

    SciTech Connect

    Mousseau, Jeffrey, D.; Jansen, John, R.; Janke, David, H.; Plowman, Catherine, M.

    2003-02-26

    Improved waste minimization practices at the Department of Energy's (DOE) Idaho National Engineering and Environmental Laboratory (INEEL) are leading to a 15% reduction in the generation of hazardous and radioactive waste. Bechtel, BWXT Idaho, LLC (BBWI), the prime management and operations contractor at the INEEL, applied the Six Sigma improvement process to the INEEL Waste Minimization Program to review existing processes and define opportunities for improvement. Our Six Sigma analysis team: composed of an executive champion, process owner, a black belt and yellow belt, and technical and business team members used this statistical based process approach to analyze work processes and produced ten recommendations for improvement. Recommendations ranged from waste generator financial accountability for newly generated waste to enhanced employee recognition programs for waste minimization efforts. These improvements have now been implemented to reduce waste generation rates and are producing positive results.

  5. Achieving Actionable Results from Available Inputs: Metamodels Take Building Energy Simulations One Step Further

    SciTech Connect

    Horsey, Henry; Fleming, Katherine; Ball, Brian; Long, Nicholas

    2016-08-26

    Modeling commercial building energy usage can be a difficult and time-consuming task. The increasing prevalence of optimization algorithms provides one path for reducing the time and difficulty. Many use cases remain, however, where information regarding whole-building energy usage is valuable, but the time and expertise required to run and post-process a large number of building energy simulations is intractable. A relatively underutilized option to accurately estimate building energy consumption in real time is to pre-compute large datasets of potential building energy models, and use the set of results to quickly and efficiently provide highly accurate data. This process is called metamodeling. In this paper, two case studies are presented demonstrating the successful applications of metamodeling using the open-source OpenStudio Analysis Framework. The first case study involves the U.S. Department of Energy's Asset Score Tool, specifically the Preview Asset Score Tool, which is designed to give nontechnical users a near-instantaneous estimated range of expected results based on building system-level inputs. The second case study involves estimating the potential demand response capabilities of retail buildings in Colorado. The metamodel developed in this second application not only allows for estimation of a single building's expected performance, but also can be combined with public data to estimate the aggregate DR potential across various geographic (county and state) scales. In both case studies, the unique advantages of pre-computation allow building energy models to take the place of topdown actuarial evaluations. This paper ends by exploring the benefits of using metamodels and then examines the cost-effectiveness of this approach.

  6. Achieving the NOAA Arctic Action Plan: The Missing Permafrost Element - Permafrost Forecasting Listening Session Results

    NASA Astrophysics Data System (ADS)

    Buxbaum, T. M.; Thoman, R.; Romanovsky, V. E.

    2015-12-01

    Permafrost is ground at or below freezing for at least two consecutive years. It currently occupies 80% of Alaska. Permafrost temperature and active layer thickness (ALT) are key climatic variables for monitoring permafrost conditions. Active layer thickness is the depth that the top layer of ground above the permafrost thaws each summer season and permafrost temperature is the temperature of the frozen permafrost under this active layer. Knowing permafrost conditions is key for those individuals working and living in Alaska and the Arctic. The results of climate models predict vast changes and potential permafrost degradation across Alaska and the Arctic. NOAA is working to implement its 2014 Arctic Action Plan and permafrost forecasting is a missing piece of this plan. The Alaska Center for Climate Assessment and Policy (ACCAP), using our webinar software and our diverse network of statewide stakeholder contacts, hosted a listening session to bring together a select group of key stakeholders. During this listening session the National Weather Service (NWS) and key permafrost researchers explained what is possible in the realm of permafrost forecasting and participants had the opportunity to discuss and share with the group (NWS, researchers, other stakeholders) what is needed for usable permafrost forecasting. This listening session aimed to answer the questions: Is permafrost forecasting needed? If so, what spatial scale is needed by stakeholders? What temporal scales do stakeholders need/want? Are there key times (winter, fall freeze-up, etc.) or locations (North Slope, key oil development areas, etc.) where forecasting would be most applicable and useful? Are there other considerations or priority needs we haven't thought of regarding permafrost forecasting? This presentation will present the results of that listening session.

  7. Nebraska STARS: Achieving Results

    ERIC Educational Resources Information Center

    Roschewski, Pat; Isernhagen, Jody; Dappen, Leon

    2006-01-01

    In 2000, the state of Nebraska passed legislation requiring the assessment of student performance on content standards, but its requirements were very different from those of any other state. Nebraska created what has come to be known as STARS (School-based Teacher-led Assessment and Reporting System). Under STARS, each of Nebraska's nearly 500…

  8. Using Performance Management To Achieve Quality Program Results. A Technical Assistance Guide. Research Report 89-03.

    ERIC Educational Resources Information Center

    Laventhol & Horwath, Philadelphia, PA.

    This guide provides assistance in using two primary management tools--the performance standards and performance-based, fixed unit price contracts--to achieve satisfactory results in Job Training Partnership Act (JTPA) programs. The guide is organized in six chapters. Chapter 1 reviews the original purpose of the JTPA and introduces the investment…

  9. Fifteen Years of Collaborative Innovation and Achievement: NASA Nebraska Space Grant Consortium 15-Year Program Performance and Results Report

    NASA Technical Reports Server (NTRS)

    Schaaf, Michaela M.; Bowen, Brent D.; Fink, Mary M.; Nickerson, Jocelyn S.; Avery, Shelly; Carstenson, Larry; Dugan, James; Farritor, Shane; Joyce, James; Rebrovich, Barb

    2003-01-01

    Condensing five years of significant work into a brief narrative fitting PPR requirements gave the affiliates of the Nebraska Space Grant a valuable chance for reflection. Achievements of Space Grant in Nebraska were judiciously chosen for this document that best illustrate the resultant synergism of this consortium, keeping in mind that these examples are only a representation of greater activity throughout the state. Following are highlights of many of the finer and personal achievements for Nebraska Space Grant. The Consortium welcomes inquiries to elaborate on any of these accomplishments.

  10. Establishing Reliable Cognitive Change in Children with Epilepsy: The Procedures and Results for a Sample with Epilepsy

    ERIC Educational Resources Information Center

    van Iterson, Loretta; Augustijn, Paul B.; de Jong, Peter F.; van der Leij, Aryan

    2013-01-01

    The goal of this study was to investigate reliable cognitive change in epilepsy by developing computational procedures to determine reliable change index scores (RCIs) for the Dutch Wechsler Intelligence Scales for Children. First, RCIs were calculated based on stability coefficients from a reference sample. Then, these RCIs were applied to a…

  11. Reliability of the peak-analysis results in gamma-ray spectrometry for high relative peak-area uncertainties.

    PubMed

    Korun, M; Vodenik, B; Zorko, B

    2015-11-01

    When measurement results with values near the decision threshold are being considered, a relative uncertainty of 60% is expected. Since such measurement results can be reported, the performance of the peak-analysing software for gamma-ray spectra needs to be examined for peaks that have a large relative uncertainty. The investigation was performed on a series of spectra measured with a HPGe detector under identical counting conditions. It was found that under a limit value of the relative peak area uncertainty the peak-analysis results are reliable with respect to both the peak location and the peak area evaluation. At relative uncertainties exceeding this uncertainty, the probability of type-II errors increases and a systematic influence on the peak area occurs, which originates in fluctuations of the continuous background in the vicinity of the peak. For the counting conditions used in this investigation, the limit relative uncertainty is about 35%, and whereas a systematic influence can be taken into account by a correction factor, the frequency of the type-II errors can only be reduced at the expense of increasing the frequency of the type-I errors.

  12. Coping Styles and Achievement: A Cross-National Study of School Children. Volume I of V Volumes: The Theory, Design, and Validation Results.

    ERIC Educational Resources Information Center

    Peck, Robert F.

    This study undertook to develop an improved conceptual system for explaining effective behavior; to build reliable measures of the components of that behavior; to develop and apply the measures internationally; and to validate the measures and concepts against objective criteria of achievement. An eight-nation team defined three sets of components…

  13. Monetary Incentives in Support of Academic Achievement: Results of a Randomized Field Trial Involving High-Achieving, Low-Resource, Ethnically Diverse Urban Adolescents

    ERIC Educational Resources Information Center

    Spencer, Margaret Beale; Noll, Elizabeth; Cassidy, Elaine

    2005-01-01

    Significant resources have been directed at understanding and alleviating the achievement gap in education. Most programs focused on this aim rely on a top-down approach, including funding for infrastructure improvement, curriculum development, class size, and teacher salaries. This article presents findings from a randomized field trial that…

  14. Reliability, Maintainability, and Life Cycle Cost Effects of Commercial Off-the-Shelf Equipment. Volume I. Technical Results.

    DTIC Science & Technology

    1983-02-01

    DEIECOMt4ERCIAL DETERMINE/ PREDICT CONDUCT 4ORMALIZE FF-THE-SHELF RELIABILITY AND LCC LCC VALUES LFiTE4TIV ANALYSI--,jMAINTAINABILITY SV LUES D ASSIGN...NUMSER RADC-TR-83-29 Vol I (of two) ,b -A/9 Y!2 _5- 4. TITLE (and Subelft.) S. TYPE OF REPORT 6 PERIOD COVERED RELIABILITY , MAINTAINABILITY, AND LIFE...environment. The guidelines were to define for a Program Manager the advantages/disadvantages of each class in terms of reliability , maintainability, cost

  15. Quality assurance and reliability sub-committee W88-0/Mk5 weapon assessment NSA lab test results (u)

    SciTech Connect

    Whitney, Earl M

    2010-11-29

    The purpose of this report is to gather appropriate level of relevant stockpile surveillance data to assess trends in the NEP quality, reliability, performance, and safety over the life of the system. The objectives are to gather relevant stockpile data to assess NEP quality and trends and to develop metrics to assess the suitability of the surveillance sampling regime to meet assessment process requirements.

  16. Integrated modular engine - Reliability assessment

    NASA Astrophysics Data System (ADS)

    Parsley, R. C.; Ward, T. B.

    1992-07-01

    A major driver in the increased interest in integrated modular engine configurations is the desire for ultra reliability for future rocket propulsion systems. The concept of configuring multiple sets of turbomachinery networked to multiple thrust chamber assemblies has been identified as an approach with potential to achieve significant reliability enhancement. This paper summarizes the results of a reliability study comparing networked systems vs. discrete engine installations, both with and without major module and engine redundancy. The study was conducted for gas generator, expander, and staged combustion cycles. The results are representative of either booster or upper-stage applications and are indicative of either plug or nonplug installation philosophies.

  17. Fifteen Years of Collaborative Innovation and Achievement: NASA Nebraska Space Grant Consortium 15-Year Program Performance and Results Report

    NASA Technical Reports Server (NTRS)

    Schaaf, Michaela M. (Editor); Bowen, Brent D.; Fink, Mary M.; Nickerson, Jocelyn S.; Avery Shelly; Calamaio, Caprice; Carstenson, Larry; Dugan, James; Farr, Lynne; Farritor, Shane

    2003-01-01

    This 15-year evaluation serves as a summary document highlighting the numerous and complete successes of the Nebraska Space Grant Program. Innovation has been highlighted through significant new endeavors during this 5-year period, such as placement of students and faculty at NASA Centers and the expansion of NSGC Native American Outreach Programs. While the last national program evaluation resulted in Nebraska s ranking as the top Capability Enhancement Consortium, and 5th best overall, Nebraska felt there was room for significant growth and development. This has been validated through the recent competitive attainment of Designated Grant status and has allowed for the exploration of new initiatives, as well as the expansion of already successful programs. A comprehensive strategic planning effort has involved all Nebraska representative entities and has guided Nebraska Space Grant through the evaluation period, providing a basis for continual advancement. Nebraska rigorously employs evaluation techniques to ensure that stated outcomes and metrics are achieved and that weaknesses are identified and corrected. With this coordinated approach, Nebraska expects that the next 5 years will yield new opportunities for significant achievement. Nebraska Space Grant will embrace new national endeavors, including the integration of Pender Public Schools -Nebraska s NASA Explorer School, geospatial initiatives, and the National Student Satellite Program.

  18. Low template STR typing: effect of replicate number and consensus method on genotyping reliability and DNA database search results.

    PubMed

    Benschop, Corina C G; van der Beek, Cornelis P; Meiland, Hugo C; van Gorp, Ankie G M; Westen, Antoinette A; Sijen, Titia

    2011-08-01

    To analyze DNA samples with very low DNA concentrations, various methods have been developed that sensitize short tandem repeat (STR) typing. Sensitized DNA typing is accompanied by stochastic amplification effects, such as allele drop-outs and drop-ins. Therefore low template (LT) DNA profiles are interpreted with care. One can either try to infer the genotype by a consensus method that uses alleles confirmed in replicate analyses, or one can use a statistical model to evaluate the strength of the evidence in a direct comparison with a known DNA profile. In this study we focused on the first strategy and we show that the procedure by which the consensus profile is assembled will affect genotyping reliability. In order to gain insight in the roles of replicate number and requested level of reproducibility, we generated six independent amplifications of samples of known donors. The LT methods included both increased cycling and enhanced capillary electrophoresis (CE) injection [1]. Consensus profiles were assembled from two to six of the replications using four methods: composite (include all alleles), n-1 (include alleles detected in all but one replicate), n/2 (include alleles detected in at least half of the replicates) and 2× (include alleles detected twice). We compared the consensus DNA profiles with the DNA profile of the known donor, studied the stochastic amplification effects and examined the effect of the consensus procedure on DNA database search results. From all these analyses we conclude that the accuracy of LT DNA typing and the efficiency of database searching improve when the number of replicates is increased and the consensus method is n/2. The most functional number of replicates within this n/2 method is four (although a replicate number of three suffices for samples showing >25% of the alleles in standard STR typing). This approach was also the optimal strategy for the analysis of 2-person mixtures, although modified search strategies may be

  19. Formal design and verification of a reliable computing platform for real-time control. Phase 2: Results

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Divito, Ben L.

    1992-01-01

    The design and formal verification of the Reliable Computing Platform (RCP), a fault tolerant computing system for digital flight control applications is presented. The RCP uses N-Multiply Redundant (NMR) style redundancy to mask faults and internal majority voting to flush the effects of transient faults. The system is formally specified and verified using the Ehdm verification system. A major goal of this work is to provide the system with significant capability to withstand the effects of High Intensity Radiated Fields (HIRF).

  20. Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Marine Climates; January 2006 - December 2006

    SciTech Connect

    Building America Industrialized Housing Partnership; Building Industry Research Alliance; Building Science Consortium; Consortium for Advanced Residential Buildings; Davis Energy Group; IBACOS; National Association of Home Builders Research Center; National Renewable Energy Laboratory

    2006-12-01

    The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in the Marine Climate Region on a cost neutral basis.

  1. Evaluating Proposed Investments in Power System Reliability and Resilience: Preliminary Results from Interviews with Public Utility Commission Staff

    SciTech Connect

    LaCommare, Kristina; Larsen, Peter; Eto, Joseph

    2017-01-01

    Policymakers and regulatory agencies are expressing renewed interest in the reliability and resilience of the U.S. electric power system in large part due to growing recognition of the challenges posed by climate change, extreme weather events, and other emerging threats. Unfortunately, there has been little or no consolidated information in the public domain describing how public utility/service commission (PUC) staff evaluate the economics of proposed investments in the resilience of the power system. Having more consolidated information would give policymakers a better understanding of how different state regulatory entities across the U.S. make economic decisions pertaining to reliability/resiliency. To help address this, Lawrence Berkeley National Laboratory (LBNL) was tasked by the U.S. Department of Energy Office of Energy Policy and Systems Analysis (EPSA) to conduct an initial set of interviews with PUC staff to learn more about how proposed utility investments in reliability/resilience are being evaluated from an economics perspective. LBNL conducted structured interviews in late May-early June 2016 with staff from the following PUCs: Washington D.C. (DCPSC), Florida (FPSC), and California (CPUC).

  2. Are Bibliographic Management Software Search Interfaces Reliable?: A Comparison between Search Results Obtained Using Database Interfaces and the EndNote Online Search Function

    ERIC Educational Resources Information Center

    Fitzgibbons, Megan; Meert, Deborah

    2010-01-01

    The use of bibliographic management software and its internal search interfaces is now pervasive among researchers. This study compares the results between searches conducted in academic databases' search interfaces versus the EndNote search interface. The results show mixed search reliability, depending on the database and type of search…

  3. The Variation in Student Achievement and Behavior within a Portfolio Management Model: Early Results from New Orleans

    ERIC Educational Resources Information Center

    McEachin, Andrew J.; Welsh, Richard Osbourne; Brewer, Dominic James

    2016-01-01

    A growing number of states experimented with alternative governance structures in response to pressure to raise student achievement. Post-Katrina experimentation in New Orleans was widely regarded as a model example of new governance reforms and provided a unique opportunity to learn about the variation in student achievement and behavior within…

  4. Different Methods, Different Results: Examining the Implications of Methodological Divergence and Implicit Processes for Achievement Goal Research

    ERIC Educational Resources Information Center

    da Costa, Laura; Remedios, Richard

    2014-01-01

    Achievement goal theory is one of the most popular theories of achievement motivation. Techniques researchers have used to assess goals include standardized questionnaires and interviews. One curious finding is that participants whose self-report questionnaire responses strongly indicate they operate with a performance goal do not make performance…

  5. Staff commitment to providing tobacco dependence in drug treatment: Reliability, validity, and results of a national survey.

    PubMed

    Hunt, Jamie J; Cupertino, A Paula; Gajewski, Byron J; Jiang, Yu; Ronzani, Telmo M; Richter, Kimber P

    2014-06-01

    Although most people in treatment for illicit drug use smoke cigarettes, few facilities offer any form of treatment for tobacco dependence. One reason for this may be that drug treatment staff have varying levels of commitment to treat tobacco. We developed and validated a 14-item Tobacco Treatment Commitment Scale (TTCS), using 405 participants in leadership positions in drug treatment facilities. We first conducted a confirmatory factor analysis to evaluate 4 a priori domains suggested by our original set of 38 items-this did not produce a good fit (comparative fit index [CFI] = 0.782, root mean square error of approximation [RMSEA] = 0.067). We then conducted a series of exploratory factor analyses to produce a more precise and reliable scale. The final confirmatory factor analysis indicated a 3-factor solution, produced a good fit (CFI = 0.950, RMSEA = 0.058), and had substantial unified reliability of 0.975. The final TTCS contained 14 items in 3 domains: "Tobacco is less harmful than other drugs," "It's not our job to treat tobacco," and "Tobacco treatment will harm clients." These constructs account for most of the variance in the survey items and emerged as major sentiments driving staff commitment to providing tobacco services. The TTCS can be used to understand the role of staff attitudes in the adoption of tobacco services in this important treatment setting.

  6. Assuring reliability program effectiveness.

    NASA Technical Reports Server (NTRS)

    Ball, L. W.

    1973-01-01

    An attempt is made to provide simple identification and description of techniques that have proved to be most useful either in developing a new product or in improving reliability of an established product. The first reliability task is obtaining and organizing parts failure rate data. Other tasks are parts screening, tabulation of general failure rates, preventive maintenance, prediction of new product reliability, and statistical demonstration of achieved reliability. Five principal tasks for improving reliability involve the physics of failure research, derating of internal stresses, control of external stresses, functional redundancy, and failure effects control. A final task is the training and motivation of reliability specialist engineers.

  7. Evaluation of a laboratory system intended for use in physicians' offices. I. Reliability of results produced by trained laboratory technologists.

    PubMed

    Belsey, R; Goitein, R K; Baer, D M

    1987-07-17

    The accuracy and precision of the Kodak DT-60 tabletop chemistry analyzer were evaluated in the clinical laboratory at the Portland (Ore) Veterans Administration Medical Center, and its operational throughout and cost were estimated. All DT-60 tests that were studied exhibited clinically acceptable precision and, except for the glucose method, accuracy. The accuracy of the glucose method was indeterminate with the available data. Throughput under field conditions was found to be less than half of the manufacturer's claim. The estimated supply cost per test could vary from $1.20 to $5.49 per test, depending on the test type and the number of assays expected to be performed daily. The instrument seems to be accurate, precise, and generally reliable when operated by professional medical technologists.

  8. Formal design and verification of a reliable computing platform for real-time control (phase 3 results)

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Divito, Ben L.; Holloway, C. Michael

    1994-01-01

    In this paper the design and formal verification of the lower levels of the Reliable Computing Platform (RCP), a fault-tolerant computing system for digital flight control applications, are presented. The RCP uses NMR-style redundancy to mask faults and internal majority voting to flush the effects of transient faults. Two new layers of the RCP hierarchy are introduced: the Minimal Voting refinement (DA_minv) of the Distributed Asynchronous (DA) model and the Local Executive (LE) Model. Both the DA_minv model and the LE model are specified formally and have been verified using the Ehdm verification system. All specifications and proofs are available electronically via the Internet using anonymous FTP or World Wide Web (WWW) access.

  9. Quantitative Assessment of Motor and Sensory/Motor Acquisition in Handicapped and Nonhandicapped Infants and Young Children. Volume II: Interobserver Reliability Results for the Procedures.

    ERIC Educational Resources Information Center

    Guess, Doug; And Others

    The second of a three volume report on a University of Kansas approach to developing quantitative measures of motor and perceptual motor functioning in nonhandicapped and severely/multiply handicapped infants and young children presents interobserver reliability results from the measures described in volume 1. Some studies also include a limited…

  10. Physical activity and academic achievement across the curriculum: Results from a 3-year cluster-randomized trial.

    PubMed

    Donnelly, Joseph E; Hillman, Charles H; Greene, Jerry L; Hansen, David M; Gibson, Cheryl A; Sullivan, Debra K; Poggio, John; Mayo, Matthew S; Lambourne, Kate; Szabo-Reed, Amanda N; Herrmann, Stephen D; Honas, Jeffery J; Scudder, Mark R; Betts, Jessica L; Henley, Katherine; Hunt, Suzanne L; Washburn, Richard A

    2017-02-11

    We compared changes in academic achievement across 3years between children in elementary schools receiving the Academic Achievement and Physical Activity Across the Curriculum intervention (A+PAAC), in which classroom teachers were trained to deliver academic lessons using moderate-to-vigorous physical activity (MVPA) compared to a non-intervention control. Elementary schools in eastern Kansas (n=17) were cluster randomized to A+PAAC (N=9, target ≥100min/week) or control (N=8). Academic achievement (math, reading, spelling) was assessed using the Wechsler Individual Achievement Test-Third Edition (WIAT-III) in a sample of children (A+PAAC=316, Control=268) in grades 2 and 3 at baseline (Fall 2011) and repeated each spring across 3years. On average 55min/week of A+PACC lessons were delivered each week across the intervention. Baseline WIAT-III scores (math, reading, spelling) were significantly higher in students in A+PAAC compared with control schools and improved in both groups across 3years. However, linear mixed modeling, accounting for baseline between group differences in WIAT-III scores, ethnicity, family income, and cardiovascular fitness, found no significant impact of A+PAAC on any of the academic achievement outcomes as determined by non-significant group by time interactions. A+PAAC neither diminished or improved academic achievement across 3-years in elementary school children compared with controls. Our target of 100min/week of active lessons was not achieved; however, students attending A+PAAC schools received an additional 55min/week of MVPA which may be associated with both physical and mental health benefits, without a reduction in time devoted to academic instruction.

  11. Mathematics beliefs and instructional strategies in achievement of elementary-school students in Japan: results from the TIMSS 2003 assessment.

    PubMed

    House, J Daniel

    2007-04-01

    Recent findings concerning mathematics assessment indicate that students in Japan consistently score above international averages. Researchers have examined specific mathematics beliefs and instructional strategies associated with mathematics achievement for students in Japan. This study examined relationships among self-beliefs, classroom instructional strategies, and mathematics achievement for a large national sample of students (N=4,207) from the TIMSS 2003 international sample of fourth graders in Japan. Several significant relationships between mathematics beliefs and test scores were found; a number of classroom teaching strategies were also significantly associated with test scores. However, multiple regression using the complete set of five mathematics beliefs and five instructional strategies explained only 25.1% of the variance in mathematics achievement test scores.

  12. Neural network boiler optimization of efficiency, emission, and reliability with TVA Kingston Unit 3 low NOx optimization test results

    SciTech Connect

    Chang, P.S.; Poston, J.M.; Schroech, K.A.; Hou, H.S.

    1995-12-31

    Boiler performance optimization includes the preservation of efficiency, emission, capacity, and reliability. Competitive pressures require cost reduction and environmental compliance. It is a challenge for utility personnel to balance these requirements often demand tradeoffs. The Clean Air Act Amendment requires utilities to reduce NOx emission. NOx emission reduction has often been accomplished by installation of new low NOx burners. Boiler tuning for NOx control can be used as an alternative to low NOx burner installation. Specifically in tangentially-fired boilers, boiler tuning can be very effective in NOx reduction. A PC-based computer software program was developed to assist the tuning process. This software, System Optimization Analysis Program (SOAP), is a neural network based code which uses the self-adaptation learning process, with an adaptive filter added for data noise control. SOAP can use historical data as the knowledge base and provides a fast optimal solution to adaptive control problems. SOAP was tested at TVA`s Kingston Unit 3 tangentially coal-fired furnace for NOx reduction. With a well-organized test plan, the optimized solution was reached with 16 tests at each test series load level. SOAP will be used for other plant equipment or system optimization, such as pulverizer performance, combustion system optimization, compared thermal performance design, and boiler tube leak detection and allocation.

  13. Evolution of the concept of Capacity-building, results achieved during the past years and the future

    NASA Astrophysics Data System (ADS)

    Laffaiteur, M.; Camacho, S.

    -faring countries and developing countries. A strategy has been presented by the Action Team in order to implement a strategy aimed at increasing again the impact of the various initiatives already going on. The promotion of the sharing of educational materials and information could be facilitated by a network of bodies in UN Member States, dedicated organizations and UN regional centres. This presentation will aim to show the current status of this issue and to present results already achieved and the way forward.

  14. Does a web-based feedback training program result in improved reliability in clinicians' ratings of the Global Assessment of Functioning (GAF) Scale?

    PubMed

    Støre-Valen, Jakob; Ryum, Truls; Pedersen, Geir A F; Pripp, Are H; Jose, Paul E; Karterud, Sigmund

    2015-09-01

    The Global Assessment of Functioning (GAF) Scale is used in routine clinical practice and research to estimate symptom and functional severity and longitudinal change. Concerns about poor interrater reliability have been raised, and the present study evaluated the effect of a Web-based GAF training program designed to improve interrater reliability in routine clinical practice. Clinicians rated up to 20 vignettes online, and received deviation scores as immediate feedback (i.e., own scores compared with expert raters) after each rating. Growth curves of absolute SD scores across the vignettes were modeled. A linear mixed effects model, using the clinician's deviation scores from expert raters as the dependent variable, indicated an improvement in reliability during training. Moderation by content of scale (symptoms; functioning), scale range (average; extreme), previous experience with GAF rating, profession, and postgraduate training were assessed. Training reduced deviation scores for inexperienced GAF raters, for individuals in clinical professions other than nursing and medicine, and for individuals with no postgraduate specialization. In addition, training was most beneficial for cases with average severity of symptoms compared with cases with extreme severity. The results support the use of Web-based training with feedback routines as a means to improve the reliability of GAF ratings performed by clinicians in mental health practice. These results especially pertain to clinicians in mental health practice who do not have a masters or doctoral degree.

  15. The Impact of Every Classroom, Every Day on High School Student Achievement: Results from a School-Randomized Trial

    ERIC Educational Resources Information Center

    Early, Diane M.; Berg, Juliette K.; Alicea, Stacey; Si, Yajuan; Aber, J. Lawrence; Ryan, Richard M.; Deci, Edward L.

    2016-01-01

    Every Classroom, Every Day (ECED) is a set of instructional improvement interventions designed to increase student achievement in math and English/language arts (ELA). ECED includes three primary components: (a) systematic classroom observations by school leaders, (b) intensive professional development and support for math teachers and…

  16. Teacher Perceptions of Alternate Assessments Based on Alternate Achievement Standards: Results from a Three-State Survey

    ERIC Educational Resources Information Center

    Restorff, Diane; Sharpe, Michael; Abery, Brian; Rodriguez, Michael; Kim, Nam Keol

    2012-01-01

    The purpose of this study was to investigate teachers' perceptions of the impact of alternate assessments based on alternate achievement standards (AA-AAS). We used a survey of 401 teachers from three states to probe teacher perspectives across a wide range of topics. Our study found teacher perceptions were more universal than state specific. The…

  17. Can Research Design Explain Variation in Head Start Research Results? A Meta-Analysis of Cognitive and Achievement Outcomes

    ERIC Educational Resources Information Center

    Shager, Hilary M.; Schindler, Holly S.; Magnuson, Katherine A.; Duncan, Greg J.; Yoshikawa, Hirokazu; Hart, Cassandra M. D.

    2013-01-01

    This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and…

  18. Challenges and Opportunities for Promoting Student Achievement through Large-Scale Assessment Results: Research, Reflections, and Future Directions

    ERIC Educational Resources Information Center

    Decker, Dawn M.; Bolt, Sara E.

    2008-01-01

    The intent of large-scale assessment systems is to promote student achievement toward specific standards by holding schools accountable for the performance of all students. However, it is difficult to know whether large-scale assessment systems are having this intended effect as they are currently implemented. In this article, the authors examine…

  19. Evaluation of a laboratory system intended for use in physicians' offices. II. Reliability of results produced by health care workers without formal or professional laboratory training.

    PubMed

    Belsey, R; Vandenbark, M; Goitein, R K; Baer, D M

    1987-07-17

    The Kodak DT-60 tabletop chemistry analyzer was evaluated with standardized protocols to determine the system's precision and accuracy when operated by four volunteers (a secretary, a licensed practical nurse, and two family medicine residents) in a simulated office laboratory. The variability of the results was found to be significantly greater than the variability of results produced by medical technologists who analyzed the same samples during the same study period with another DT-60 placed in the hospital laboratory. The source(s) of increased variance needs to be identified so the system can be modified or new control procedures can be developed to ensure the reliability of results used in patient care. Prospective purchasers, manufacturers, and patients need this kind of objective information about the reliability of results produced by systems intended for use in physicians' office laboratories.

  20. Reliability of aneuploidy estimates in human sperm: Results of fluorescence in situ hybridization studies using two different scoring criteria

    SciTech Connect

    Martin, R.H. |; Rademaker, A.

    1994-09-01

    Aneuploidy estimates for individual chromosomes in human sperm have varied more than 10-fold in different laboratories using fluorescence in situ hybridization (FISH). These laboratories use different scoring criteria in the assessment of a disomic sperm. In order to determine reliable estimates of aneuploidy, we have investigated whether scoring criteria affect the aneuploidy frequency in human sperm. Aneuploidy estimates for chromosomes 1(pUC1.77), 12(pBR12), X(XC) and Y(DYZ3Z) were obtained in human sperm from five donors using multicolor FISH analysis to provide an internal control to differentiate between nullisomy and lack of hybridization and between disomy and diploidy. Disomy frequencies were obtained by scoring a minimum of 10,000 sperm for each chromosome probe per donor. This analysis was replicated for two scoring criteria: one scoring criterion used one-half a signal domain as the minimum distance between two signals to be counted as two and thus disomic; the other scoring criterion set one signal domain as the minimum distance between two signals. A total of 120,870 sperm were assessed using one half domain as the scoring criterion and 113,478 were scored using one domain as the criterion. The mean percent disomy for chromosomes 1, 12, X, Y and XY was .18, .16, .15, .19, .25 respectively using the one-half domain criterion and .08, .17, .07, .12, .16 respectively using the one domain criterion. The percent disomy decreased significantly with use of one domain as the minimum distance for signal separation for all chromosomes except chromosome number 12. These lower disomy frequencies correlated well with frequencies derived from human sperm karyotypes analyzed in our laboratory. This suggests that the fluorescent signals for chromosomes 1, X and Y split into more than one domain in decondensed interphase sperm and use of the one-half domain criterion leads to an overestimate of aneuploidy frequencies.

  1. Dose evaluation for paediatric chest x-ray examinations in Brazil and Sudan: low doses and reliable examinations can be achieved in developing countries

    NASA Astrophysics Data System (ADS)

    Mohamadain, K. E. M.; da Rosa, L. A. R.; Azevedo, A. C. P.; Guebel, M. R. N.; Boechat, M. C. B.; Habani, F.

    2004-03-01

    Radiation protection in paediatric radiology deserves special attention since it is assumed that children are more sensitive to radiation than adults. The aim of this work is to estimate the entrance skin dose (ESD), the body organ dose (BOD) and the effective dose (E) for chest x-ray exposure of paediatric patients in five large units, three in Sudan and two in Brazil, and to compare the results obtained in both countries with each other and with other values obtained by some European countries. Two examination projections have been investigated, namely, postero-anterior (PA) and antero-posterior (AP). The age intervals considered were: 0-1 year, 1-5 years, 5-10 years and 10-15 years. The results have been obtained with the use of a software called DoseCal. Results of mean ESD for the age interval 1-5 years and AP projection are: 66 µGy (Instituto de Pediatria e Puericultura Martagão Gesteira—IPPMG Hospital), 41, 86 and 68 µGy (Instituto Fernandes Figueira—IFF Hospital), 161 µGy (Omdurman Hospital), 395 µGy (Khartoum Hospital) and 23 µGy (Ahmed Gasim Hospital). In the case of the IFF Hospital, the results refer, respectively, to rooms 1, 2 and for the six mobile equipments. The reference dose values given by the European Guidelines were exceeded in the Khartoum Hospital whilst in all the other hospitals results obtained were below CEC reference values and comparable with the results found in Sweden, Germany, Spain and Italy. The mean E for the same age interval was 11 µSv in the IPPMG, 6, 15 and 11 µSv in the IFF, respectively for rooms 1, 2 and the 6 mobiles, 25 µSv in the Omdurman Hospital, 45 µSv in the Khartoum Hospital and 3 µSv in the Ahmed Gasim Hospital. These are some examples of the large discrepancies that have been detected in this survey.

  2. Rapid and reliable seismic source characterization in earthquake early warning systems: current methodologies, results, and new perspectives

    NASA Astrophysics Data System (ADS)

    Colombelli, Simona; Zollo, Aldo

    2016-10-01

    In the present paper, we provided a review of the main principles and methodologies on which the current earthquake early warning systems are grounded and will also provide a perspective view for next future developments and improvements. First, we introduce the standard methodologies for the source characterization in earthquake early warning, with a special focus on the real-time earthquake magnitude determination. We discuss the suitability of existent methodologies and empirical regression laws for very large events. We then present the different approaches for the rapid prediction of the ground shaking and of the potential damaged zone, both based on traditional seismic data and on the use of continuous GPS data. Finally, the last part of the paper provides the perspective view toward a next generation of early warning systems, linking new research achievements about the earthquake rupture nucleation and the development of new methods/technologies aimed at a fast and high-resolution, real-time modeling of the ongoing source process and accurate prediction of the quake shaking at the regional and local scale.

  3. Examining the quality of the 'Healthy Eating and Physical Activity in Schools' (HEPS) quality checklist: German results on usability and reliability.

    PubMed

    Dadaczynski, Kevin; Boye, Jutta

    2015-12-01

    The aim of the present study was to examine the usability and reliability of the HEPS quality checklist (Healthy Eating and Physical Activity in Schools), an instrument developed to assess the quality of school-based programmes on healthy eating and physical activity. With regard to usability, health promotion experts (n = 15) were asked to apply the HEPS quality checklist and to fill out a questionnaire about its comprehensibility and usability. To examine inter-rater reliability (IRR) a criteria-based selection of German school programmes on healthy eating and physical activity (n = 14) was randomly allocated to two programme pools and assessed independently by the authors. Results of the pilot testing revealed a high overall satisfaction with the HEPS quality checklist and a high willingness to use it or to recommend it to others. Furthermore, the checklist was perceived to be comprehensive and clearly structured. The assessment results of programme pool 1 revealed unsatisfactory Cohen's Kappa coefficients (IRR) and moderate intra-class correlations (ICC). After the HEPS manual guide had been amended with regard to its anchoring, the results of programme pool 2 showed substantial improvements with regard to IRR and ICC. In summary, the adapted HEPS quality checklist is a usable and reliable instrument for the quality assessment of school-based programmes on healthy eating and physical activity. The findings suggest that the HEPS checklist should be applied by two sufficiently trained raters.

  4. A quantitative assessment of reliability of the TOPAZ-2 space NPS reactor unit based on ground development results

    SciTech Connect

    Ponomarev-Stepnoi, N.N.; Nechaev, Y.A.; Khazanovich, I.M.; Samodelov, V.N.; Zakharov, S.M.

    1997-01-01

    The paper discusses life-limiting factors (parameters) and statistics of random sudden failures, revealed in the course of ground development, for 4 given subsystems of the TOPAZ-2 space NPS reactor unit. Results are presented of a quantitative assessment of the lower confidence limits of the probability of failure-free operation. {copyright} {ital 1997 American Institute of Physics.}

  5. A quantitative assessment of reliability of the TOPAZ-2 space NPS reactor unit based on ground development results

    SciTech Connect

    Ponomarev-Stepnoi, Nikolai N.; Nechaev, Yuri A.; Khazanovich, Igor M.; Samodelov, Victor N.; Zakharov, Sergei M.

    1997-01-10

    The paper discusses life-limiting factors (parameters) and statistics of random sudden failures, revealed in the course of ground development, for 4 given subsystems of the TOPAZ-2 space NPS reactor unit. Results are presented of a quantitative assessment of the lower confidence limits of the probability of failure-free operation.

  6. Spatial evapotranspiration, rainfall and land use data in water accounting - Part 2: Reliability of water accounting results for policy decisions in the Awash basin

    NASA Astrophysics Data System (ADS)

    Karimi, P.; Bastiaanssen, W. G. M.; Sood, A.; Hoogeveen, J.; Peiser, L.; Bastidas-Obando, E.; Dost, R.

    2014-01-01

    Water Accounting Plus (WA+) is a framework that summarizes complex hydrological processes and water management issues in river basins. The framework is designed to use satellite based measurements of land and water as input data. A concern associated with the use of satellite measurements is their accuracy. This study focuses on the impact of the error in remote sensing measurements on water accounting and information provided to policy makers. The Awash basin in the central rift valley in Ethiopia is used as a case study to explore the reliability of WA+ outputs, in the light of input data errors. The Monte Carlo technique was used for stochastic simulation of WA+ outputs over a period of three years. The results show that the stochastic mean of the majority of WA+ parameters and performance indicators are within 5% deviation from the original values. Stochastic simulation can be used as part of a standard procedure for WA+ water accounting because it provides the error bandwidth for every WA+ output, which is essential information for sound decision making. The majority of WA+ parameters and performance indicators have a Coefficient of Variation (CV) of less than 20% which implies that they are reliable. The results also indicate that the "utilized flow" and "basin closure fraction" (the degree to which available water in a basin is utilized) have a high margin of error and thus a low reliability. As such it is recommended that they are not used to formulate important policy decisions.

  7. EPA Science to Achieve Results (STAR) Centers for Water Research on National Priorities Related to a Systems View of Nutrient Management

    EPA Science Inventory

    This poster describes the missions and objectives of four newly-awarded Science to Achieve Results (STAR) Centers. There is also a description of how the projects fit together to meet solicitation research questions.

  8. Intelligence and Achievement Test Results of Kindergarten-Age Children in England, Ireland and the United States

    ERIC Educational Resources Information Center

    Vane, Julia R.

    1973-01-01

    Results support the hypothesis that the differences between the test results of the middle and lower classes in the individual countries are greater than the differences between the same classes in the three different countries. (Author)

  9. Occupational health nurses’ achievement of competence and comfort in respiratory protection and preferred learning methods results of a nationwide survey.

    PubMed

    Burgel, Barbara J; Novak, Debra A; Carpenter, Holly Elizabeth; Gruden, MaryAnn; Lachat, Ann M; Taormina, Deborah

    2014-02-01

    Additional findings are presented from a 2012 nationwide survey of 2,072 occupational health nurses regarding how they achieved competence in respiratory protection, their preferred methods of learning, and how they motivated employees to use respiratory protection. On-the-job training, taking a National Institute for Occupational Safety and Health spirometry course, or attending professional conferences were the primary ways occupational health nurses gained respiratory protection knowledge. Attending professional conferences was the preferred method of learning, varying by type of industry and years of occupational health nurse experience. Employee motivational strategies were not widely used; the most common strategy was to tailor respiratory protection training to workplace culture. Designing training methods that match learning preferences, within the context of the organization's safety and quality improvement culture, is a key recommendation supported by the literature and these findings. Including respiratory protection content and competencies in all levels of academic nursing education is an additional recommendation. Additional research is needed to link training strategies with consistent and correct use of respiratory protection by employees.

  10. Creating Highly Reliable Accountable Care Organizations.

    PubMed

    Vogus, Timothy J; Singer, Sara J

    2016-12-01

    Accountable Care Organizations' (ACOs) pursuit of the triple aim of higher quality, lower cost, and improved population health has met with mixed results. To improve the design and implementation of ACOs we look to organizations that manage similarly complex, dynamic, and tightly coupled conditions while sustaining exceptional performance known as high-reliability organizations. We describe the key processes through which organizations achieve reliability, the leadership and organizational practices that enable it, and the role that professionals can play when charged with enacting it. Specifically, we present concrete practices and processes from health care organizations pursuing high-reliability and from early ACOs to illustrate how the triple aim may be met by cultivating mindful organizing, practicing reliability-enhancing leadership, and identifying and supporting reliability professionals. We conclude by proposing a set of research questions to advance the study of ACOs and high-reliability research.

  11. Reliability Results of NERSC Systems

    SciTech Connect

    Petascale Data Storage Institute; Mokhtarani, Akbar; Mokhtarani, Akbar; Kramer, William; Hick, Jason

    2008-05-27

    In order to address the needs of future scientific applications for storing and accessing large amounts of data in an efficient way, one needs to understand the limitations of current technologies and how they may cause systeminstability or unavailability. A number of factors can impact system availability ranging from facility-wide power outage to a single point of failure such as network switches or global file systems. In addition, individual component failure in a system can degrade the performance of that system. This paper focuses on analyzing both of these factors and their impacts on the computational and storage systems at NERSC. Component failure data presented in this report primarily focuses on disk drive in on of the computational system and tape drive failure in HPSS. NERSC collected available component failure data and system-wide outages for its computational and storage systems over a six-year period and made them available to the HPC community through the Petascale Data Storage Institute.

  12. The Contribution of the Responsive Classroom Approach on Children's Academic Achievement: Results from a Three Year Longitudinal Study

    ERIC Educational Resources Information Center

    Rimm-Kaufman, Sara E.; Fan, Xitao; Chiu, Yu-Jen; You, Wenyi

    2007-01-01

    This paper reports the results of a quasi-experimental study on the contribution of the Responsive Classroom ("RC") Approach to elementary school children's reading and math performance over one-, two-, and three-year periods. All children enrolled in six schools (3 intervention and 3 control schools in a single district) were the participants in…

  13. Preventing Underage Drinking: Using Getting to Outcomes with the SAMHSA Strategic Prevention Framework to Achieve Results. RAND Technical Report

    ERIC Educational Resources Information Center

    Imm, Pamela; Chinman, Matthew; Wandersman, Abraham; Rosenbloom, David; Guckenburg, Sarah; Leis, Roberta

    2007-01-01

    Underage drinking is a significant problem in the United States: Alcohol is the primary contributor to the leading causes of death among adolescents. As a result, communitywide strategies to prevent underage drinking are more important than ever. Such strategies depend on the involvement and education of adolescents, parents, law enforcement …

  14. Spatial evapotranspiration, rainfall and land use data in water accounting - Part 2: Reliability of water acounting results for policy decisions in the Awash Basin

    NASA Astrophysics Data System (ADS)

    Karimi, P.; Bastiaanssen, W. G. M.; Sood, A.; Hoogeveen, J.; Peiser, L.; Bastidas-Obando, E.; Dost, R. J.

    2015-01-01

    Water Accounting Plus (WA+) is a framework that summarizes complex hydrological processes and water management issues in river basins. The framework is designed to use satellite-based measurements of land and water variables and processes as input data. A general concern associated with the use of satellite measurements is their accuracy. This study focuses on the impact of the error in remote sensing measurements on water accounting and information provided to policy makers. The Awash Basin in the central Rift Valley in Ethiopia is used as a case study to explore the reliability of WA+ outputs, in the light of input data errors. The Monte Carlo technique was used for stochastic simulation of WA+ outputs over a period of 3 yr. The results show that the stochastic mean of the majority of WA+ parameters and performance indicators are within 5% deviation from the original WA+ values based on one single calculation. Stochastic computation is proposed as a standard procedure for WA+ water accounting because it provides the uncertainty bandwidth for every WA+ output, which is essential information for sound decision-making processes. The majority of WA+ parameters and performance indicators have a coefficient of variation (CV) of less than 20%, which implies that they are reliable and provide consistent information on the functioning of the basin. The results of the Awash Basin also indicate that the utilized flow and basin closure fraction (the degree to which available water in a basin is utilized) have a high margin of error and thus a low reliability. As such, the usefulness of them in formulating important policy decisions for the Awash Basin is limited. Other river basins will usually have a more accurate assessment of the discharge in the river mouth.

  15. Canine olfaction as an alternative to analytical instruments for disease diagnosis: understanding 'dog personality' to achieve reproducible results.

    PubMed

    Hackner, Klaus; Pleil, Joachim

    2017-01-09

    Recent literature has touted the use of canine olfaction as a diagnostic tool for identifying pre-clinical disease status, especially cancer and infection from biological media samples. Studies have shown a wide range of outcomes, ranging from almost perfect discrimination, all the way to essentially random results. This disparity is not likely to be a detection issue; dogs have been shown to have extremely sensitive noses as proven by their use for tracking, bomb detection and search and rescue. However, in contrast to analytical instruments, dogs are subject to boredom, fatigue, hunger and external distractions. These challenges are of particular importance in a clinical environment where task repetition is prized, but not as entertaining for a dog as chasing odours outdoors. The question addressed here is how to exploit the intrinsic sensitivity and simplicity of having a dog simply sniff out disease, in the face of variability in behavior and response.

  16. Ophthalmologists' practice patterns and challenges in achieving optimal management for glaucoma in Nigeria: results from a nationwide survey

    PubMed Central

    Kyari, Fatima; Nolan, Winifred; Gilbert, Clare

    2016-01-01

    Purpose of the study Glaucoma, a chronic non-communicable disease, and leading cause of irreversible blindness worldwide is a public health problem in Nigeria, with a prevalence of 5.02% in people aged ≥40 years. The purpose of this nationwide survey was to assess Nigerian ophthalmologists’ practice patterns and their constraints in managing glaucoma. Study design Ophthalmologists were sent a semistructured questionnaire on how they manage glaucoma, their training in glaucoma care, where they practice, their access to equipment for diagnosis and treatment, whether they use protocols and the challenges they face in managing patients with glaucoma. Results 153/250 ophthalmologists in 80 centres completed questionnaires. Although 79% felt their training was excellent or good, 46% needed more training in glaucoma diagnosis and surgery. All had ophthalmoscopes, 93% had access to applanation tonometers, 81% to visual field analysers and 29% to laser machines (in 19 centres). 3 ophthalmologists had only ophthalmoscopes and schiøtz tonometers. For 85%, a glaucomatous optic disc was the most important feature that would prompt glaucoma work-up. Only 56% routinely performed gonioscopy and 61% used slit-lamp stereoscopic biomicroscopy for disc assessment. Trabeculectomy (with/without antimetabolites) was the only glaucoma surgery performed with one mention of canaloplasty. Poor compliance with medical treatment (78%) and low acceptance of surgery (71%) were their greatest challenges. Conclusions This study indicates that a systems-oriented approach is required to enhance ophthalmologist's capability for glaucoma care. Strategies to improve glaucoma management include strengthening poorly equipped centres including provision of lasers and training, and improving patients’ awareness and education on glaucoma. PMID:27729348

  17. Achievements and bottlenecks in humanitarian demining EU-funded research: final results from the EC DELVE project

    NASA Astrophysics Data System (ADS)

    Sahli, Hichem; Bruschini, Claudio; Van Kempen, Luc; Schleijpen, Ric; den Breejen, Eric

    2008-04-01

    The EC DELVE Support Action project has analyzed the bottlenecks in the transfer of Humanitarian Demining (HD) technology from technology development to the use in the field, and drawn some lessons learned, basing itself on the assessment of the European Humanitarian Demining Research and Technology Development (RTD) situation from early 1990 until 2006. The situation at the European level was analyzed with emphasis on activities sponsored by the European Commission (EC). This was also done for four European countries and Japan, with emphasis on national activities. The developments in HD during the last 10 years underline the fact that in a number of cases demining related developments have been terminated or at least put on hold. The study also showed that the funding provided by the EC under the Framework Program for RTD has led directly to the creation of an extensive portfolio of Humanitarian Demining technology development projects. The latter provided a range of research and supporting measures addressing the critical issues identified as a result of the regulatory policies developed in the field of Humanitarian Demining over the last ten years. However, the range of instruments available to the EC to finance the necessary research and development were limited, to pre-competitive research. The EC had no tools or programs to directly fund actual product development. As a first consequence, the EC funding program for development of technology for Humanitarian Demining unfortunately proved to be largely unsuitable for the small-scale development needed in a field where there is only a very limited market. As a second consequence, most of the research has been demonstrator-oriented. Moreover, the timeframe for RTD in Humanitarian Demining has not been sufficiently synchronized with the timeframe of the EC policies and regulations. The separation of the Mine Action and RTD funding streams in the EC did also negatively affect the take-up of new technologies. As a

  18. Power electronics reliability analysis.

    SciTech Connect

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  19. The Efforts to Improve Mathematics Learning Achievement Results of High School Students as Required by Competency-Based Curriculum and Lesson Level-Based Curriculum

    ERIC Educational Resources Information Center

    Sidabutar, Ropinus

    2016-01-01

    The research was aimed to investigate the effect of various, innovated teaching models to improved the student's achievement in various topic in Mathematics. The study was conduct experiment by using innovated teaching with contextual, media and web which are the compared. with conventional teaching method. The result showed the innovation in the…

  20. Effects of Problem-Based Learning Model versus Expository Model and Motivation to Achieve for Student's Physic Learning Result of Senior High School at Class XI

    ERIC Educational Resources Information Center

    Prayekti

    2016-01-01

    "Problem-based learning" (PBL) is one of an innovative learning model which can provide an active learning to student, include the motivation to achieve showed by student when the learning is in progress. This research is aimed to know: (1) differences of physic learning result for student group which taught by PBL versus expository…

  1. Mathematics Beliefs and Achievement of Elementary School Students in Japan and the United States: Results from the Third International Mathematics and Science Study

    ERIC Educational Resources Information Center

    House, J. Daniel

    2006-01-01

    Student self-beliefs are significantly related to several types of academic achievement. In addition, results from international assessments have indicated that students in Japan have typically scored above international averages (D. L. Kelly, I. V. S. Mullis, & M. O. Martin, 2000). In this study, the author examined relationships between…

  2. Cinacalcet HCl and Concurrent Low-dose Vitamin D Improves Treatment of Secondary Hyperparathyroidism in Dialysis Patients Compared with Vitamin D Alone: The ACHIEVE Study Results

    PubMed Central

    Fishbane, Steven; Shapiro, Warren B.; Corry, Dalila B.; Vicks, Steven L.; Roppolo, Michael; Rappaport, Kenneth; Ling, Xiang; Goodman, William G.; Turner, Stewart; Charytan, Chaim

    2008-01-01

    Background and objectives: Patients with chronic kidney disease (CKD) receiving dialysis often develop secondary hyperparathyroidism with disturbed calcium and phosphorus metabolism. The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (KDOQI) was established to guide treatment practices for these disorders. The ACHIEVE study was designed to test two treatment strategies for achieving KDOQI goals. Design, setting, participants, measurements: Individuals on hemodialysis treated with vitamin D sterols were enrolled in this 33-week study. Subjects were randomly assigned to treatment with either cinacalcet and low-dose vitamin D (Cinacalcet-D) or flexible vitamin D alone (Flex-D) to achieve KDOQI-recommended bone mineral targets. ACHIEVE included a 6-week screening phase, including vitamin D washout, a 16-week dose-titration phase, and an 11-week assessment phase. Results: Of 173 subjects enrolled, 83% of Cinacalcet-D and 67% of Flex-D subjects completed the study. A greater proportion of Cinacalcet-D versus Flex-D subjects had a ≥30% reduction in parathyroid hormone (PTH) (68% versus 36%, P < 0.001) as well as PTH ≤300 pg/ml (44% versus 23%, P = 0.006). The proportion of subjects simultaneously achieving targets for intact PTH (150–300 pg/ml) and calcium-phosphorus product (Ca×P) (<55 mg2/dl2) was also greater (21% versus 14%), but this was not statistically significant. This was attributable to 19% of Cinacalcet-D subjects with a PTH value below the KDOQI target range. Conclusions: Achievement of KDOQI targets was difficult, especially with Flex-D. Maintaining calcium and phosphorus target values precluded the use of vitamin D doses necessary to lower PTH to within the narrow target range and highlighted limitations inherent to the KDOQI treatment algorithm. PMID:18945995

  3. Brief Report: Interrater Reliability of Clinical Diagnosis and DSM-IV Criteria for Autistic Disorder: Results of the DSM-IV Autism Field Trial.

    ERIC Educational Resources Information Center

    Klin, Ami; Lang, Jason; Cicchetti, Domenic V.; Volkmar, Fred R.

    2000-01-01

    This study examined the inter-rater reliability of clinician-assigned diagnosis of autism using or not using the criteria specified in the Diagnostic and Statistical Manual IV (DSM-IV). For experienced raters there was little difference in reliability in the two conditions. However, a clinically significant improvement in diagnostic reliability…

  4. Reliability based design optimization: Formulations and methodologies

    NASA Astrophysics Data System (ADS)

    Agarwal, Harish

    Modern products ranging from simple components to complex systems should be designed to be optimal and reliable. The challenge of modern engineering is to ensure that manufacturing costs are reduced and design cycle times are minimized while achieving requirements for performance and reliability. If the market for the product is competitive, improved quality and reliability can generate very strong competitive advantages. Simulation based design plays an important role in designing almost any kind of automotive, aerospace, and consumer products under these competitive conditions. Single discipline simulations used for analysis are being coupled together to create complex coupled simulation tools. This investigation focuses on the development of efficient and robust methodologies for reliability based design optimization in a simulation based design environment. Original contributions of this research are the development of a novel efficient and robust unilevel methodology for reliability based design optimization, the development of an innovative decoupled reliability based design optimization methodology, the application of homotopy techniques in unilevel reliability based design optimization methodology, and the development of a new framework for reliability based design optimization under epistemic uncertainty. The unilevel methodology for reliability based design optimization is shown to be mathematically equivalent to the traditional nested formulation. Numerical test problems show that the unilevel methodology can reduce computational cost by at least 50% as compared to the nested approach. The decoupled reliability based design optimization methodology is an approximate technique to obtain consistent reliable designs at lesser computational expense. Test problems show that the methodology is computationally efficient compared to the nested approach. A framework for performing reliability based design optimization under epistemic uncertainty is also developed

  5. Mathematics beliefs and achievement of elementary school students in Japan and the United States: results from the Third International Mathematics and Science Study.

    PubMed

    House, J Daniel

    2006-03-01

    Student self-beliefs are significantly related to several types of academic achievement. In addition, results from international assessments have indicated that students in Japan have typically scored above international averages (D. L. Kelly, I. V. S. Mullis, & M. O. Martin, 2000). In this study, the author examined relationships between mathematics beliefs and achievement of elementary school-aged students in the United States and Japan. The students had participated in the Third International Mathematics and Science Study (TIMSS; A. E. Beaton et al., 1996). The author examined several self-beliefs and used variance estimation techniques for complex sampling designs. The author identified a number of significant relationships between self-beliefs and mathematics achievement. Students who attributed success in mathematics to controllable factors (e.g., hard work, studying at home) showed higher test scores whereas students who attributed success in mathematics at school to external factors (e.g., good luck) tended to earn lower mathematics test scores. These results extend the findings of previous research results because the author examined large national samples of students in cross-cultural settings as part of a comprehensive international assessment.

  6. Test Reliability by Ability Level of Examinees.

    ERIC Educational Resources Information Center

    Green, Kathy; Sax, Gilbert

    Achievement test reliability as a function of ability was determined for multiple sections of a large university French class (n=193). A 5-option multiple-choice examination was constructed, least attractive distractors were eliminated based on the instructor's judgment, and the resulting three forms of the examination (i.e. 3-, 4-, or 5-choice…

  7. Person Reliability

    ERIC Educational Resources Information Center

    Lumsden, James

    1977-01-01

    Person changes can be of three kinds: developmental trends, swells, and tremors. Person unreliability in the tremor sense (momentary fluctuations) can be estimated from person characteristic curves. Average person reliability for groups can be compared from item characteristic curves. (Author)

  8. Optimizing results from pQCT: reliability of operator-dependent pQCT variables in cadavers and humans with low bone mass.

    PubMed

    Ashe, Maureen C; Liu-Ambrose, Teresa; Khan, Karim M; White, Neil; McKay, Heather A

    2005-01-01

    Peripheral quantitative computed tomography (pQCT) can assess bone geometric properties and separate cortical from trabecular bone. Despite pQCT's potential benefits for research, most reliability and accuracy studies have used a constant acquisition and analysis protocol. There are, however, numerous steps in the pQCT scan acquisition and analysis that are operator dependent. Whether or not these influence the quality of the pQCT scans and, potentially, the precision and validity of the data collected has been little explored. We investigated how pQCT outputs changed when operator-dependent parameters were varied, particularly when the bone of interest was of low mineral density. We found that bone parameters and scan failure rate varied significantly depending on the acquisition resolution; only one scan slice at the 10 and 30% radius is required to maintain adequate precision, and reference lines for sites should use a reproducible landmark. These results provide a foundation for recommending scan acquisition and analysis options for patients with low bone mass.

  9. Short-time xylem relaxation results in reliable quantification of embolism in grapevine petioles and sheds new light on their hydraulic strategy.

    PubMed

    Hochberg, Uri; Herrera, Jose Carlos; Cochard, Hervé; Badel, Eric

    2016-06-01

    In recent years, the validity of embolism quantification methods has been questioned, especially for long-vesseled plants. Some studies have suggested that cutting xylem while under tension, even under water, might generate artificial cavitation. Accordingly, a rehydration procedure prior to hydraulic measurements has been recommended to avoid this artefact. On the other hand, concerns have been raised that xylem refilling might occur when samples are rehydrated. Here, we explore the potential biases affecting embolism quantification for grapevine (Vitis vinifera L.) petioles harvested under tension or after xylem relaxation. We employ direct visualization of embolism through X-ray micro-computed tomography (microCT) to test for the occurrence of fast refilling (artifactually low per cent loss of conductivity (PLC) due to rehydration prior to sample harvest) as well as excision-induced embolism (artifactually high embolism due to air introduction during harvest). Additionally, we compared the response functions of both stomatal regulation and xylem embolism to xylem pressure (Ψx). Short-time (20 min) xylem tension relaxation prior to the hydraulic measurement resulted in a lower degree of embolism than found in samples harvested under native tensions, and yielded xylem vulnerability curves similar to the ones obtained using direct microCT visualization. Much longer periods of hydration (overnight) were required before xylem refilling was observed to occur. In field-grown vines, over 85% of stomatal closure occurred at less negative Ψx than that required to induce 12% PLC. Our results demonstrate that relaxation of xylem tension prior to hydraulic measurement allows for the reliable quantification of native embolism in grapevine petioles. Furthermore, we find that stomatal regulation is sufficiently conservative to avoid transpiration-induced cavitation. These results suggest that grapevines have evolved a strategy of cavitation resistance, rather than one of

  10. Effects of a free school breakfast programme on children's attendance, academic achievement and short-term hunger: results from a stepped-wedge, cluster randomised controlled trial

    PubMed Central

    Gorton, Delvina; Turley, Maria; Jiang, Yannan; Michie, Jo; Maddison, Ralph; Hattie, John

    2013-01-01

    Background Free school breakfast programmes (SBPs) exist in a number of high-income countries, but their effects on educational outcomes have rarely been evaluated in randomised controlled trials. Methods A 1-year stepped-wedge, cluster randomised controlled trial was undertaken in 14 New Zealand schools in low socioeconomic resource areas. Participants were 424 children, mean age 9±2 years, 53% female. The intervention was a free daily SBP. The primary outcome was children's school attendance. Secondary outcomes were academic achievement, self-reported grades, sense of belonging at school, behaviour, short-term hunger, breakfast habits and food security. Results There was no statistically significant effect of the breakfast programme on children's school attendance. The odds of children achieving an attendance rate <95% was 0.76 (95% CI 0.56 to 1.02) during the intervention phase and 0.93 (95% CI 0.67 to 1.31) during the control phase, giving an OR of 0.81 (95% CI 0.59 to 1.11), p=0.19. There was a significant decrease in children's self-reported short-term hunger during the intervention phase compared with the control phase, demonstrated by an increase of 8.6 units on the Freddy satiety scale (95% CI 3.4 to 13.7, p=0.001). There were no effects of the intervention on any other outcome. Conclusions A free SBP did not have a significant effect on children's school attendance or academic achievement but had significant positive effects on children's short-term satiety ratings. More frequent programme attendance may be required to influence school attendance and academic achievement. Trial registration Australian New Zealand Clinical Trials Registry (ANZCTR)—ACTRN12609000854235. PMID:23043203

  11. Illustrated structural application of universal first-order reliability method

    NASA Technical Reports Server (NTRS)

    Verderaime, V.

    1994-01-01

    The general application of the proposed first-order reliability method was achieved through the universal normalization of engineering probability distribution data. The method superimposes prevailing deterministic techniques and practices on the first-order reliability method to surmount deficiencies of the deterministic method and provide benefits of reliability techniques and predictions. A reliability design factor is derived from the reliability criterion to satisfy a specified reliability and is analogous to the deterministic safety factor. Its application is numerically illustrated on several practical structural design and verification cases with interesting results and insights. Two concepts of reliability selection criteria are suggested. Though the method was developed to support affordable structures for access to space, the method should also be applicable for most high-performance air and surface transportation systems.

  12. Flight control electronics reliability/maintenance study

    NASA Technical Reports Server (NTRS)

    Dade, W. W.; Edwards, R. H.; Katt, G. T.; Mcclellan, K. L.; Shomber, H. A.

    1977-01-01

    Collection and analysis of data are reported that concern the reliability and maintenance experience of flight control system electronics currently in use on passenger carrying jet aircraft. Two airlines B-747 airplane fleets were analyzed to assess the component reliability, system functional reliability, and achieved availability of the CAT II configuration flight control system. Also assessed were the costs generated by this system in the categories of spare equipment, schedule irregularity, and line and shop maintenance. The results indicate that although there is a marked difference in the geographic location and route pattern between the airlines studied, there is a close similarity in the reliability and the maintenance costs associated with the flight control electronics.

  13. Recalibrating software reliability models

    NASA Technical Reports Server (NTRS)

    Brocklehurst, Sarah; Chan, P. Y.; Littlewood, Bev; Snell, John

    1990-01-01

    In spite of much research effort, there is no universally applicable software reliability growth model which can be trusted to give accurate predictions of reliability in all circumstances. Further, it is not even possible to decide a priori which of the many models is most suitable in a particular context. In an attempt to resolve this problem, techniques were developed whereby, for each program, the accuracy of various models can be analyzed. A user is thus enabled to select that model which is giving the most accurate reliability predicitons for the particular program under examination. One of these ways of analyzing predictive accuracy, called the u-plot, in fact allows a user to estimate the relationship between the predicted reliability and the true reliability. It is shown how this can be used to improve reliability predictions in a completely general way by a process of recalibration. Simulation results show that the technique gives improved reliability predictions in a large proportion of cases. However, a user does not need to trust the efficacy of recalibration, since the new reliability estimates prodcued by the technique are truly predictive and so their accuracy in a particular application can be judged using the earlier methods. The generality of this approach would therefore suggest that it be applied as a matter of course whenever a software reliability model is used.

  14. Recalibrating software reliability models

    NASA Technical Reports Server (NTRS)

    Brocklehurst, Sarah; Chan, P. Y.; Littlewood, Bev; Snell, John

    1989-01-01

    In spite of much research effort, there is no universally applicable software reliability growth model which can be trusted to give accurate predictions of reliability in all circumstances. Further, it is not even possible to decide a priori which of the many models is most suitable in a particular context. In an attempt to resolve this problem, techniques were developed whereby, for each program, the accuracy of various models can be analyzed. A user is thus enabled to select that model which is giving the most accurate reliability predictions for the particular program under examination. One of these ways of analyzing predictive accuracy, called the u-plot, in fact allows a user to estimate the relationship between the predicted reliability and the true reliability. It is shown how this can be used to improve reliability predictions in a completely general way by a process of recalibration. Simulation results show that the technique gives improved reliability predictions in a large proportion of cases. However, a user does not need to trust the efficacy of recalibration, since the new reliability estimates produced by the technique are truly predictive and so their accuracy in a particular application can be judged using the earlier methods. The generality of this approach would therefore suggest that it be applied as a matter of course whenever a software reliability model is used.

  15. Reliability physics

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Ross, R. G., Jr.

    1984-01-01

    Speakers whose topics relate to the reliability physics of solar arrays are listed and their topics briefly reviewed. Nine reports are reviewed ranging in subjects from studies of photothermal degradation in encapsulants and polymerizable ultraviolet stabilizers to interface bonding stability to electrochemical degradation of photovoltaic modules.

  16. Is There a Relationship between Physical Fitness and Academic Achievement? Positive Results from Public School Children in the Northeastern United States

    ERIC Educational Resources Information Center

    Chomitz, Virginia R.; Slining, Meghan M.; McGowan, Robert J.; Mitchell, Suzanne E.; Dawson, Glen F.; Hacker, Karen A.

    2009-01-01

    Objectives: To determine relationships between physical fitness and academic achievement in diverse, urban public school children. Methods: This cross-sectional study used public school data from 2004 to 2005. Academic achievement was assessed as a passing score on Massachusetts Comprehensive Assessment System (MCAS) achievement tests in…

  17. A highly reliable LAN protocol

    NASA Astrophysics Data System (ADS)

    Weaver, A. C.

    1986-10-01

    As a research project for NASA's Langley Research Center, a variation on the military standard for avionics buses was developed to increase fault tolerance. The resulting protocol, called implicit token passing (ITP), replaces an explicit token with brief 'soundoff' messages from all nodes participating on the LAN. ITP features high throughput and bounded message delay, and achieves high reliability through tolerance of failed nodes and automatic resynchronization when failed nodes are revived. The protocol is ideally suited for a bus topology and fiber optic media.

  18. 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.

  19. Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Mixed-Humid Climates; January 2006 - December 2006

    SciTech Connect

    Building America Industrialized Housing Partnership; Building Industry Research Alliance; Building Science Consortium; Consortium for Advanced Residential Buildings; Davis Energy Group; IBACOS; National Association of Home Builders Research Center; National Renewable Energy Laboratory

    2006-12-01

    The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in the Mixed-Humid Climate Region on a cost-neutral basis.

  20. Results.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Describes the Collegiate Results Instrument (CRI), which measures a range of collegiate outcomes for alumni 6 years after graduation. The CRI was designed to target alumni from institutions across market segments and assess their values, abilities, work skills, occupations, and pursuit of lifelong learning. (EV)

  1. The PiCT(®) test is a reliable alternative to the activated partial thromboplastin time in unfractionated heparin therapy management: results from a multicenter study.

    PubMed

    Brisset, A C; Ferrández, A; Krause, M; Rathbun, S; Marlar, R; Korte, W

    2016-11-01

    Essentials Activated partial thromboplastin time (APTT) or anti-Xa tests are used to monitor heparin. Prothrombinase-induced Clotting Time (PiCT) was compared to APTT in a clinical study. PiCT shows higher correlation to anti-Xa than APTT does and is more comparable between centers. PiCT demonstrates significantly higher accuracy and reliability than APTT in heparin monitoring.

  2. The morphology of islets within the porcine donor pancreas determines the isolation result: successful isolation of pancreatic islets can now be achieved from young market pigs.

    PubMed

    Krickhahn, Mareike; Bühler, Christoph; Meyer, Thomas; Thiede, Arnulf; Ulrichs, Karin

    2002-01-01

    Clinical islet allotransplantation has become an increasingly efficient "routine" therapy in recent years. Shortage of human donor organs leads to porcine pancreatic islets as a potential source for islet xenotransplantation. Yet it is still very difficult to isolate sufficient numbers of intact porcine islets, particularly from young market pigs. In the following study islets were successfully isolated from retired breeders [4806 +/- 720 islet equivalents per gram organ (IEQ/g); n = 25; 2-3 years old; RB] and also from young hybrid pigs [2868 +/- 260 IEQ/g; n = 65; 4-6 months old; HY] using LiberasePI and a modified version of Ricordi's digestion-filtration technique. As expected, isolations from RB showed significantly better results (p < 0.002). A retrospective histological analysis of almost all donor pancreases showed that the majority of organs from RB (80%) contained mainly large islets (diameter > 200 microm), in contrast to only 35% of all pancreases from HY. Remarkably, the islet size in situ, regardless whether detected in RB or HY, strongly determined the isolation result. A donor organ with predominantly large islets resulted in significantly higher numbers of IEQs compared with a donor organ with predominantly small islets [RB(Large Islets): 5680 +/- 3,318 IEQ/g (n= 20); RB(Small Islets): 1353 +/- 427 IEQ/g (n = 5); p < 0.02]. In addition, isolation results were strongly influenced by the quality of the LiberasePI batch, and therefore single batch testing is invariably required. Purification was performed using Ficoll or OptiPrep density gradient centrifugation manually or in the COBE cell processor. Although islet purity was highest when OptiPrep was used, final islet yields did not differ between the different purification methods. Our study demonstrates that islet size in situ is an extremely critical parameter for highly successful islet isolation; consequently, we are now performing a morphological screening of each donor organ prior to the

  3. Network reliability

    NASA Technical Reports Server (NTRS)

    Johnson, Marjory J.

    1985-01-01

    Network control (or network management) functions are essential for efficient and reliable operation of a network. Some control functions are currently included as part of the Open System Interconnection model. For local area networks, it is widely recognized that there is a need for additional control functions, including fault isolation functions, monitoring functions, and configuration functions. These functions can be implemented in either a central or distributed manner. The Fiber Distributed Data Interface Medium Access Control and Station Management protocols provide an example of distributed implementation. Relative information is presented here in outline form.

  4. Effects of a Universally Free, In-Classroom School Breakfast Program: Results from the Second Year of the Maryland Meals for Achievement Evaluation. Interim Report.

    ERIC Educational Resources Information Center

    Murphy, J. Michael; Rankin, Emunah; Feeney, Kelly; Kenney, Leigh; Kleinman, Ron

    Noting that many children in the United States are not well nourished despite the recent economic boom, the state of Maryland began the Maryland Meals for Achievement (MMFA) program, a demonstration project to see if providing a classroom breakfast free to all students can improve student nutrition and academic achievement. This interim report…

  5. Explaining the Achievement Gap between Indigenous and Non-Indigenous Students: An Analysis of PISA 2009 Results for Australia and New Zealand

    ERIC Educational Resources Information Center

    Song, Steve; Perry, Laura B.; McConney, Andrew

    2014-01-01

    This study investigates the relative roles of home and school variables in accounting for achievement gaps between Indigenous and non-Indigenous students in Australia and New Zealand. Using data from the Programme for International Student Assessment [PISA] 2009, our findings show that achievement gaps between Indigenous and non-Indigenous…

  6. The comparison of wavelet- and Fourier-based electromyographic indices of back muscle fatigue during dynamic contractions: validity and reliability results.

    PubMed

    da Silva, R A; Larivière, C; Arsenault, A B; Nadeau, S; Plamondon, A

    2008-01-01

    The purpose of this study was to compare the electromyographic (EMG) fatigue indices computed from short-time Fourier transform (STFT) and wavelet transform (WAV), by analyzing their criterion validity and test-retest reliability. The effect of averaging spectral estimates within and between repeated contractions (cycles) on EMG fatigue indices was also demonstrated. Thirty-one healthy subjects performed trunk flexion-extension cycles until exhaustion on a Biodex dynamometer. The load was determined theoretically as twice the L5-S1 moment produced by the trunk mass. To assess reliability, 10 subjects performed the same experimental protocol after a two-week interval. EMG signals were recorded bilaterally with 12 pairs of electrodes placed on the back muscles (at L4, L3, L1 and T10 levels), as well as on the gluteus maximus and biceps femoris. The endurance time and perceived muscle fatigue (Borg CR-10 scale) were used as fatigue criteria. EMG signals were processed using STFT and WAV to extract global (e.g, median frequency and instantaneous median frequency, respectively) or local (e.g., intensity contained in 8 frequency bands) information from the power spectrum. The slope values of these variables over time, obtained from regression analyses, were retained as EMG fatigue indices. EMG fatigue indices (STFT vs. WAV) were not significantly different within each muscle, had a variable association (Pearson's r range.: 0.06 to 0.68) with our fatigue criteria, and showed comparable reliability (Intra-class correlation range: 0.00 to 0.88), although they varied between muscles. The effect of averaging, within and between cycles, contributed to the strong association between EMG fatigue indices computed from STFT and WAV. As for EMG spectral indices of muscle fatigue, the conclusion is that both transforms carry essentially the same information.

  7. 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.

  8. Testing of reliability - Analysis tools

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J.

    1989-01-01

    An outline is presented of issues raised in verifying the accuracy of reliability analysis tools. State-of-the-art reliability analysis tools implement various decomposition, aggregation, and estimation techniques to compute the reliability of a diversity of complex fault-tolerant computer systems. However, no formal methodology has been formulated for validating the reliability estimates produced by these tools. The author presents three states of testing that can be performed on most reliability analysis tools to effectively increase confidence in a tool. These testing stages were applied to the SURE (semi-Markov Unreliability Range Evaluator) reliability analysis tool, and the results of the testing are discussed.

  9. Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in the Hot-Dry and Mixed-Dry Climates

    SciTech Connect

    Building Industry Research Alliance; Building Science Consortium; Consortium for Advanced Residential Buildings; Davis Energy Group; Florida Solar Energy Center; IBACOS; National Association of Home Builders Research Center; National Renewable Energy Laboratory

    2006-01-01

    The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in the Hot-Dry/Mixed-Dry Climate Region on a cost neutral basis.

  10. Innovative Hypofractionated Stereotactic Regimen Achieves Excellent Local Control with No Radiation Necrosis: Promising Results in the Management of Patients with Small Recurrent Inoperable GBM

    PubMed Central

    Pannullo, Susan C.; Minkowitz, Shlomo; Taube, Shoshana; Chang, Jenghwa; Parashar, Bhupesh; Christos, Paul; Wernicke, A.Gabriella

    2016-01-01

    Management of recurrent glioblastoma multiforme (GBM) remains a challenge. Several institutions reported that a single fraction of ≥ 20 Gy for small tumor burden results in excellent local control; however, this is at the expense of a high incidence of radiation necrosis (RN). Therefore, we developed a hypofractionation pattern of 33 Gy/3 fractions, which is a radiobiological equivalent of 20 Gy, with the aim to lower the incidence of RN. We reviewed records of 21 patients with recurrent GBM treated with hypofractionated stereotactic radiation therapy (HFSRT) to their 22 respective lesions. Sixty Gy fractioned external beam radiotherapy was performed as first-line treatment. Median time from primary irradiation to HFSRT was 9.6 months (range: 3.1 – 68.1 months). In HFSRT, a median dose of 33 Gy in 11 Gy fractions was delivered to the 80% isodose line that encompassed the target volume. The median tumor volume was 1.07 cm3 (range: 0.11 – 16.64 cm3). The median follow-up time after HFSRT was 9.3 months (range: 1.7 – 33.6 months). Twenty-one of 23 lesions treated (91.3%) achieved local control while 2/23 (8.7%) progressed. Median time to progression outside of the treated site was 5.2 months (range: 2.2 – 9.6 months). Progression was treated with salvage chemotherapy. Five of 21 patients (23.8%) were alive at the end of this follow-up; two patients remain disease-free. The remaining 16/21 patients (76.2%) died of disease. Treatment was well tolerated by all patients with no acute CTC/RTOG > Grade 2. There was 0% incidence of RN. A prospective trial will be underway to validate these promising results. PMID:27096136

  11. Reliability Impacts in Life Support Architecture and Technology Selection

    NASA Technical Reports Server (NTRS)

    Lange Kevin E.; Anderson, Molly S.

    2012-01-01

    Quantitative assessments of system reliability and equivalent system mass (ESM) were made for different life support architectures based primarily on International Space Station technologies. The analysis was applied to a one-year deep-space mission. System reliability was increased by adding redundancy and spares, which added to the ESM. Results were thus obtained allowing a comparison of the ESM for each architecture at equivalent levels of reliability. Although the analysis contains numerous simplifications and uncertainties, the results suggest that achieving necessary reliabilities for deep-space missions will add substantially to the life support ESM and could influence the optimal degree of life support closure. Approaches for reducing reliability impacts were investigated and are discussed.

  12. Mathematics beliefs and achievement of a national sample of Native American students: results from the Trends in International Mathematics and Science Study (TIMSS) 2003 United States assessment.

    PubMed

    House, J Daniel

    2009-04-01

    Recent mathematics assessment findings indicate that Native American students tend to score below students of the ethnic majority. Findings suggest that students' beliefs about mathematics are significantly related to achievement outcomes. This study examined relations between self-beliefs and mathematics achievement for a national sample of 130 Grade 8 Native American students from the Trends in International Mathematics and Science Study (TIMSS) 2003 United States sample of (M age = 14.2 yr., SD = 0.5). Multiple regression indicated several significant relations of mathematics beliefs with achievement and accounted for 26.7% of the variance in test scores. Students who earned high test scores tended to hold more positive beliefs about their ability to learn mathematics quickly, while students who earned low scores expressed negative beliefs about their ability to learn new mathematics topics.

  13. Developing Ultra Reliable Life Support for the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Jones, Harry W.

    2009-01-01

    Recycling life support systems can achieve ultra reliability by using spares to replace failed components. The added mass for spares is approximately equal to the original system mass, provided the original system reliability is not very low. Acceptable reliability can be achieved for the space shuttle and space station by preventive maintenance and by replacing failed units, However, this maintenance and repair depends on a logistics supply chain that provides the needed spares. The Mars mission must take all the needed spares at launch. The Mars mission also must achieve ultra reliability, a very low failure rate per hour, since it requires years rather than weeks and cannot be cut short if a failure occurs. Also, the Mars mission has a much higher mass launch cost per kilogram than shuttle or station. Achieving ultra reliable space life support with acceptable mass will require a well-planned and extensive development effort. Analysis must define the reliability requirement and allocate it to subsystems and components. Technologies, components, and materials must be designed and selected for high reliability. Extensive testing is needed to ascertain very low failure rates. Systems design should segregate the failure causes in the smallest, most easily replaceable parts. The systems must be designed, produced, integrated, and tested without impairing system reliability. Maintenance and failed unit replacement should not introduce any additional probability of failure. The overall system must be tested sufficiently to identify any design errors. A program to develop ultra reliable space life support systems with acceptable mass must start soon if it is to produce timely results for the moon and Mars.

  14. Achieving Consensus for the Design and Delivery of an Online Intervention to Support Midwives in Work-Related Psychological Distress: Results From a Delphi Study

    PubMed Central

    Clyne, Wendy

    2016-01-01

    Background Some midwives are known to experience both professional and organizational sources of psychological distress, which can manifest as a result of the emotionally demanding midwifery work, and the traumatic work environments they endure. An online intervention may be one option midwives may engage with in pursuit of effective support. However, the priorities for the development of an online intervention to effectively support midwives in work-related psychological distress have yet to be explored. Objective The aim of this study was to explore priorities in the development of an online intervention to support midwives in work-related psychological distress. Methods A two-round online Delphi study was conducted. This study invited both qualitative and quantitative data from experts recruited via a scoping literature search and social media channels. Results In total, 185 experts were invited to participate in this Delphi study. Of all participants invited to contribute, 35.7% (66/185) completed Round 1 and of those who participated in this first round, 67% (44/66) continued to complete Round 2. Out of 39 questions posed over two rounds, 18 statements (46%) achieved consensus, 21 (54%) did not. Participants were given the opportunity to write any additional comments as free text. In total, 1604 free text responses were collected and categorized into 2446 separate statements of opinion, creating a total of 442 themes. Overall, participants agreed that in order to effectively support midwives in work-related psychological distress, online interventions should make confidentiality and anonymity a high priority, along with 24-hour mobile access, effective moderation, an online discussion forum, and additional legal, educational, and therapeutic components. It was also agreed that midwives should be offered a simple user assessment to identify those people deemed to be at risk of either causing harm to others or experiencing harm themselves, and direct them to

  15. The Effects of Research-Based Curriculum Materials and Curriculum-Based Professional Development on High School Science Achievement: Results of a Cluster-Randomized Trial

    ERIC Educational Resources Information Center

    Taylor, Joseph; Kowalski, Susan; Getty, Stephen; Wilson, Christopher; Carlson, Janet

    2013-01-01

    Effective instructional materials can be valuable interventions to improve student interest and achievement in science (National Research Council [NRC], 2007); yet, analyses indicate that many science instructional materials and curricula are fragmented, lack coherence, and are not carefully articulated through a sequence of grade levels (AAAS,…

  16. Who Are the Students Who May Qualify for an Alternate Assessment Based on Modified Academic Achievement Standards (AA-MAS)?: Focus Group Results. Synthesis Report 79

    ERIC Educational Resources Information Center

    Berndt, Sandra; Ebben, Barbara; Kubinski, Eva; Sim, Grant; Liu, Kristin; Lazarus, Sheryl; Thurlow, Martha; Christian, Elizabeth

    2011-01-01

    Beginning in 2007, federal regulations to two major education laws gave state departments of education the option to develop an alternate assessment based on modified achievement standards (AA-MAS) for some students with disabilities. The regulations stated that the AA-MAS was intended for students who were being instructed in the grade-level…

  17. The rating reliability calculator

    PubMed Central

    Solomon, David J

    2004-01-01

    Background Rating scales form an important means of gathering evaluation data. Since important decisions are often based on these evaluations, determining the reliability of rating data can be critical. Most commonly used methods of estimating reliability require a complete set of ratings i.e. every subject being rated must be rated by each judge. Over fifty years ago Ebel described an algorithm for estimating the reliability of ratings based on incomplete data. While his article has been widely cited over the years, software based on the algorithm is not readily available. This paper describes an easy-to-use Web-based utility for estimating the reliability of ratings based on incomplete data using Ebel's algorithm. Methods The program is available public use on our server and the source code is freely available under GNU General Public License. The utility is written in PHP, a common open source imbedded scripting language. The rating data can be entered in a convenient format on the user's personal computer that the program will upload to the server for calculating the reliability and other statistics describing the ratings. Results When the program is run it displays the reliability, number of subject rated, harmonic mean number of judges rating each subject, the mean and standard deviation of the averaged ratings per subject. The program also displays the mean, standard deviation and number of ratings for each subject rated. Additionally the program will estimate the reliability of an average of a number of ratings for each subject via the Spearman-Brown prophecy formula. Conclusion This simple web-based program provides a convenient means of estimating the reliability of rating data without the need to conduct special studies in order to provide complete rating data. I would welcome other researchers revising and enhancing the program. PMID:15117416

  18. Reliable VLSI sequential controllers

    NASA Technical Reports Server (NTRS)

    Whitaker, S.; Maki, G.; Shamanna, M.

    1990-01-01

    A VLSI architecture for synchronous sequential controllers is presented that has attractive qualities for producing reliable circuits. In these circuits, one hardware implementation can realize any flow table with a maximum of 2(exp n) internal states and m inputs. Also all design equations are identical. A real time fault detection means is presented along with a strategy for verifying the correctness of the checking hardware. This self check feature can be employed with no increase in hardware. The architecture can be modified to achieve fail safe designs. With no increase in hardware, an adaptable circuit can be realized that allows replacement of faulty transitions with fault free transitions.

  19. Orbiter Autoland reliability analysis

    NASA Technical Reports Server (NTRS)

    Welch, D. Phillip

    1993-01-01

    The Space Shuttle Orbiter is the only space reentry vehicle in which the crew is seated upright. This position presents some physiological effects requiring countermeasures to prevent a crewmember from becoming incapacitated. This also introduces a potential need for automated vehicle landing capability. Autoland is a primary procedure that was identified as a requirement for landing following and extended duration orbiter mission. This report documents the results of the reliability analysis performed on the hardware required for an automated landing. A reliability block diagram was used to evaluate system reliability. The analysis considers the manual and automated landing modes currently available on the Orbiter. (Autoland is presently a backup system only.) Results of this study indicate a +/- 36 percent probability of successfully extending a nominal mission to 30 days. Enough variations were evaluated to verify that the reliability could be altered with missions planning and procedures. If the crew is modeled as being fully capable after 30 days, the probability of a successful manual landing is comparable to that of Autoland because much of the hardware is used for both manual and automated landing modes. The analysis indicates that the reliability for the manual mode is limited by the hardware and depends greatly on crew capability. Crew capability for a successful landing after 30 days has not been determined yet.

  20. Reliability and Maintainability Analysis of Fluidic Back-Up Flight Control System and Components.

    DTIC Science & Technology

    1981-09-01

    being used in various aircraft applications are demonstrating extremely high reliability. However, the unique design of new fluidic compo- nents results...in a very limited failure rate data base and prevents the determination of numerical values of fluidic system reliability at a sufficient confidence...Did. 6601 WWINlTTi’ G.ASUFIOATION OF TH PAGE (116 flm e UAK 80227-60 EXECUTIVE SUMMARY BACKGROUND High reliability in flight control systems is achieved

  1. Sequential Reliability Tests.

    ERIC Educational Resources Information Center

    Eiting, Mindert H.

    1991-01-01

    A method is proposed for sequential evaluation of reliability of psychometric instruments. Sample size is unfixed; a test statistic is computed after each person is sampled and a decision is made in each stage of the sampling process. Results from a series of Monte-Carlo experiments establish the method's efficiency. (SLD)

  2. The reliable assurance of detecting somatic mutations in cancer-related genes by next-generation sequencing: the results of external quality assessment in China.

    PubMed

    Zhang, Rui; Ding, Jiansheng; Han, Yanxi; Yi, Lang; Xie, Jiehong; Yang, Xin; Fan, Gaowei; Wang, Guojing; Hao, Mingju; Zhang, Dong; Zhang, Kuo; Lin, Guigao; Li, Jinming

    2016-09-06

    To evaluate the proficiencies of laboratories utilizing next-generation sequencing (NGS) to detect somatic mutations in cancer-related genes, an external quality assessment (EQA) was implemented by the National Center for Clinical Laboratories of China in 2015. We prepared a panel of samples that comprised eight samples made by mixing synthetic mutated DNA fragments with normal human genomic DNA and one reference sample containing only genomic DNA. We validated our sample panel, and then distributed it to laboratories across China. We received complete results from 64 laboratories. The performances of 51.6 % (33/64) respondent labs were acceptable and 26.6 % (17/64) of the labs returned perfect results. In total, 449 mistakes were reported, including 201 false-negatives (201/449, 44.8 %) and 222 false-positives (222/449, 49.4 %) and 26 slightly discordant results (26/449, 5.8 %). We believe these unsatisfactory results and varied performances are mainly due to the enrichment methods used, the diverse sequencing chemistries of the different NGS platforms, and other errors within the sequencing process. The results indicate that our sample panel is suitable for use in EQA studies, and that further laboratory training in targeted NGS testing is urgently required. To address this, we propose a targeted NGS workflow with details on quality assurance procedures according to the current guidelines.

  3. The reliable assurance of detecting somatic mutations in cancer-related genes by next-generation sequencing: the results of external quality assessment in China

    PubMed Central

    Han, Yanxi; Yi, Lang; Xie, Jiehong; Yang, Xin; Fan, Gaowei; Wang, Guojing; Hao, Mingju; Zhang, Dong; Zhang, Kuo; Lin, Guigao; Li, Jinming

    2016-01-01

    To evaluate the proficiencies of laboratories utilizing next-generation sequencing (NGS) to detect somatic mutations in cancer-related genes, an external quality assessment (EQA) was implemented by the National Center for Clinical Laboratories of China in 2015. We prepared a panel of samples that comprised eight samples made by mixing synthetic mutated DNA fragments with normal human genomic DNA and one reference sample containing only genomic DNA. We validated our sample panel, and then distributed it to laboratories across China. We received complete results from 64 laboratories. The performances of 51.6 % (33/64) respondent labs were acceptable and 26.6 % (17/64) of the labs returned perfect results. In total, 449 mistakes were reported, including 201 false-negatives (201/449, 44.8 %) and 222 false-positives (222/449, 49.4 %) and 26 slightly discordant results (26/449, 5.8 %). We believe these unsatisfactory results and varied performances are mainly due to the enrichment methods used, the diverse sequencing chemistries of the different NGS platforms, and other errors within the sequencing process. The results indicate that our sample panel is suitable for use in EQA studies, and that further laboratory training in targeted NGS testing is urgently required. To address this, we propose a targeted NGS workflow with details on quality assurance procedures according to the current guidelines. PMID:27542269

  4. Reliability of nucleic acid amplification methods for detection of Chlamydia trachomatis in urine: results of the first international collaborative quality control study among 96 laboratories.

    PubMed

    Verkooyen, Roel P; Noordhoek, Gerda T; Klapper, Paul E; Reid, Jim; Schirm, Jurjen; Cleator, Graham M; Ieven, Margareta; Hoddevik, Gunnar

    2003-07-01

    The first European Quality Control Concerted Action study was organized to assess the ability of laboratories to detect Chlamydia trachomatis in a panel of urine samples by nucleic acid amplification tests (NATs). The panel consisted of lyophilized urine samples, including three negative, two strongly positive, and five weakly positive samples. Ninety-six laboratories in 22 countries participated with a total of 102 data sets. Of 204 strongly positive samples 199 (97.5%) were correctly reported, and of 506 weakly positive samples 466 (92.1%) were correctly reported. In 74 (72.5%) data sets correct results were reported on all samples, and 17 data sets (16.7%) showed either one false-negative or one false-positive result. In another 11 data sets, two or more incorrect results were reported, and two data sets reported a false-positive result on one negative sample. The Roche COBAS Amplicor test was performed in 44 (43%) data sets, the Abbott LCx assay was performed in 31 (30%) data sets, the Roche Amplicor manual assay was performed in 9 (9%) data sets, an in-house PCR was performed in 9 (9%) data sets, the Becton Dickinson ProbeTec ET assay was performed in 5 (4.9%) data sets, and the GenProbe TMA assay was performed in 4 (3.9%) data sets. The results of the Roche Amplicor manual (95.6% correct), COBAS Amplicor (97.0%), and Abbott LCx (94.8%) tests were comparable (P = 0.48). The results with the in-house PCR, BD ProbeTec ET, and GenProbe TMA tests were reported correctly in 88.6, 98, and 92.5% of the tests, respectively. Freeze-drying of clinical urine specimens proved to be a successful method for generating standardized, stable, and easy-to-transport samples for the detection of C. trachomatis by using NATs. Although the results, especially the specificity, for this proficiency panel were better than most quality control studies, sensitivity problems occurred frequently, underlining the need for good laboratory practice and reference reagents to monitor the

  5. The molecular characterization of a depurinated trial DNA sample can be a model to understand the reliability of the results in forensic genetics.

    PubMed

    Fattorini, Paolo; Previderè, Carlo; Sorçaburu-Cigliero, Solange; Marrubini, Giorgio; Alù, Milena; Barbaro, Anna M; Carnevali, Eugenia; Carracedo, Angel; Casarino, Lucia; Consoloni, Lara; Corato, Silvia; Domenici, Ranieri; Fabbri, Matteo; Giardina, Emiliano; Grignani, Pierangela; Baldassarra, Stefania Lonero; Moratti, Marco; Nicolin, Vanessa; Pelotti, Susi; Piccinini, Andrea; Pitacco, Paola; Plizza, Laura; Resta, Nicoletta; Ricci, Ugo; Robino, Carlo; Salvaderi, Luca; Scarnicci, Francesca; Schneider, Peter M; Seidita, Gregorio; Trizzino, Lucia; Turchi, Chiara; Turrina, Stefania; Vatta, Paolo; Vecchiotti, Carla; Verzeletti, Andrea; De Stefano, Francesco

    2014-11-01

    The role of DNA damage in PCR processivity/fidelity is a relevant topic in molecular investigation of aged/forensic samples. In order to reproduce one of the most common lesions occurring in postmortem tissues, a new protocol based on aqueous hydrolysis of the DNA was developed in vitro. Twenty-five forensic laboratories were then provided with 3.0 μg of a trial sample (TS) exhibiting, in mean, the loss of 1 base of 20, and a molecular weight below 300 bp. Each participating laboratory could freely choose any combination of methods, leading to the quantification and to the definition of the STR profile of the TS, through the documentation of each step of the analytical approaches selected. The results of the TS quantification by qPCR showed significant differences in the amount of DNA recorded by the participating laboratories using different commercial kits. These data show that only DNA quantification "relative" to the used kit (probe) is possible, being the "absolute" amount of DNA inversely related to the length of the target region (r(2) = 0.891). In addition, our results indicate that the absence of a shared stable and certified reference quantitative standard is also likely involved. STR profiling was carried out selecting five different commercial kits and amplifying the TS for a total number of 212 multiplex PCRs, thus representing an interesting overview of the different analytical protocols used by the participating laboratories. Nine laboratories decided to characterize the TS using a single kit, with a number of amplifications varying from 2 to 12, obtaining only partial STR profiles. Most of the participants determined partial or full profiles using a combination of two or more kits, and a number of amplifications varying from 2 to 27. The performance of each laboratory was described in terms of number of correctly characterized loci, dropped-out markers, unreliable genotypes, and incorrect results. The incidence of unreliable and incorrect

  6. Robust fusion with reliabilities weights

    NASA Astrophysics Data System (ADS)

    Grandin, Jean-Francois; Marques, Miguel

    2002-03-01

    The reliability is a value of the degree of trust in a given measurement. We analyze and compare: ML (Classical Maximum Likelihood), MLE (Maximum Likelihood weighted by Entropy), MLR (Maximum Likelihood weighted by Reliability), MLRE (Maximum Likelihood weighted by Reliability and Entropy), DS (Credibility Plausibility), DSR (DS weighted by reliabilities). The analysis is based on a model of a dynamical fusion process. It is composed of three sensors, which have each it's own discriminatory capacity, reliability rate, unknown bias and measurement noise. The knowledge of uncertainties is also severely corrupted, in order to analyze the robustness of the different fusion operators. Two sensor models are used: the first type of sensor is able to estimate the probability of each elementary hypothesis (probabilistic masses), the second type of sensor delivers masses on union of elementary hypotheses (DS masses). In the second case probabilistic reasoning leads to sharing the mass abusively between elementary hypotheses. Compared to the classical ML or DS which achieves just 50% of correct classification in some experiments, DSR, MLE, MLR and MLRE reveals very good performances on all experiments (more than 80% of correct classification rate). The experiment was performed with large variations of the reliability coefficients for each sensor (from 0 to 1), and with large variations on the knowledge of these coefficients (from 0 0.8). All four operators reveal good robustness, but the MLR reveals to be uniformly dominant on all the experiments in the Bayesian case and achieves the best mean performance under incomplete a priori information.

  7. The effects of the L/N-type calcium channel blocker (cilnidipine) on sympathetic hyperactive morning hypertension: results from ACHIEVE-ONE.

    PubMed

    Kario, Kazuomi; Ando, Shin-ichi; Kido, Hidenori; Nariyama, Jin; Takiuchi, Shin; Yagi, Tetsuo; Shimizu, Toshiki; Eguchi, Kazuo; Ohno, Minoru; Kinoshita, Osamu; Yamada, Takahisa

    2013-02-01

    The Ambulatory Blood Pressure Control and Home Blood Pressure (Morning and Evening) Lowering By N-Channel Blocker Cilnidipine (ACHIEVE-ONE) trial is a large-scale clinical study on blood pressure (BP) and pulse rate (PR) in the real world with use of cilnidipine, a unique L/N-type Ca channel blocker, possessing a suppressive action on increased sympathetic activity in patients with essential hypertension. The effects of cilnidipine on morning hypertension were examined. The authors examined 2319 patients treated with cilnidipine for 12 weeks. Clinic systolic BP (SBP) decreased by 19.6 mm Hg from 155.0 mm Hg, whereas morning SBP decreased by 17.0 mm Hg from 152.9 mm Hg after 12-week cilnidipine treatment. Cilnidipine reduced both morning SBP and PR more markedly in patients with higher baseline morning SBP (-3.2 mm Hg and -1.3 beats per minute in the first quartile of morning SBP, -30.9 mm Hg and -3.2 beats per minute in the fourth quartile), and also reduced both morning PR and SBP more markedly in patients with higher baseline morning PR (0.6 beats per minute and -15.6 mm Hg in <70 beats per minute, and -9.7 beats per minute and -20.2 mm Hg in ≥85 beats per minute). Cilnidipine significantly reduced BP and PR in hypertensive patients at the clinic and at home, especially with higher BP and PR in the morning.

  8. 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.

  9. Reliability Impacts in Life Support Architecture and Technology Selection

    NASA Technical Reports Server (NTRS)

    Lange, Kevin E.; Anderson, Molly S.

    2011-01-01

    Equivalent System Mass (ESM) and reliability estimates were performed for different life support architectures based primarily on International Space Station (ISS) technologies. The analysis was applied to a hypothetical 1-year deep-space mission. High-level fault trees were initially developed relating loss of life support functionality to the Loss of Crew (LOC) top event. System reliability was then expressed as the complement (nonoccurrence) this event and was increased through the addition of redundancy and spares, which added to the ESM. The reliability analysis assumed constant failure rates and used current projected values of the Mean Time Between Failures (MTBF) from an ISS database where available. Results were obtained showing the dependence of ESM on system reliability for each architecture. Although the analysis employed numerous simplifications and many of the input parameters are considered to have high uncertainty, the results strongly suggest that achieving necessary reliabilities for deep-space missions will add substantially to the life support system mass. As a point of reference, the reliability for a single-string architecture using the most regenerative combination of ISS technologies without unscheduled replacement spares was estimated to be less than 1%. The results also demonstrate how adding technologies in a serial manner to increase system closure forces the reliability of other life support technologies to increase in order to meet the system reliability requirement. This increase in reliability results in increased mass for multiple technologies through the need for additional spares. Alternative parallel architecture approaches and approaches with the potential to do more with less are discussed. The tall poles in life support ESM are also reexamined in light of estimated reliability impacts.

  10. Is the General Self-Efficacy Scale a Reliable Measure to be used in Cross-Cultural Studies? Results from Brazil, Germany and Colombia.

    PubMed

    Damásio, Bruno F; Valentini, Felipe; Núñes-Rodriguez, Susana I; Kliem, Soeren; Koller, Sílvia H; Hinz, Andreas; Brähler, Elmar; Finck, Carolyn; Zenger, Markus

    2016-05-26

    This study evaluated cross-cultural measurement invariance for the General Self-efficacy Scale (GSES) in a large Brazilian (N = 2.394) and representative German (N = 2.046) and Colombian (N = 1.500) samples. Initially, multiple-indicators multiple-causes (MIMIC) analyses showed that sex and age were biasing items responses on the total sample (2 and 10 items, respectively). After controlling for these two covariates, a multigroup confirmatory factor analysis (MGCFA) was employed. Configural invariance was attested. However, metric invariance was not supported for five items, in a total of 10, and scalar invariance was not supported for all items. We also evaluated the differences between the latent scores estimated by two models: MIMIC and MGCFA unconstraining the non-equivalent parameters across countries. The average difference was equal to |.07| on the estimation of the latent scores, and 22.8% of the scores were biased in at least .10 standardized points. Bias effects were above the mean for the German group, which the average difference was equal to |.09|, and 33.7% of the scores were biased in at least .10. In synthesis, the GSES did not provide evidence of measurement invariance to be employed in this cross-cultural study. More than that, our results showed that even when controlling for sex and age effects, the absence of control on items parameters in the MGCFA analyses across countries would implicate in bias of the latent scores estimation, with a higher effect for the German population.

  11. Reliability of environmental fate modeling results for POPs based on various methods of determining the air/water partition coefficient (log KAW)

    NASA Astrophysics Data System (ADS)

    Odziomek, K.; Gajewicz, A.; Haranczyk, M.; Puzyn, T.

    2013-07-01

    Air-water partition coefficient (KAW) is one of the key parameters determining environmental behavior of Persistent Organic Pollutants (POPs). Experimentally measured values of KAW are still unavailable for majority of POPs, thus alternative methods of supplying data, including Quantitative Structure-Property Relationships (QSPR) modeling, are often in use. In this paper, applicability of two QSPR methods of predicting KAW were compared with each other in the context of further application of the predicted data in environmental transport and fate studies. According to the first (indirect) method, KAW is calculated from previously predicted values of octanol-water (KOW) and octanol-air (KOA) partition coefficients. In the second (direct) approach, KAW is calculated, based on the estimated value of Henry's law constant (KH) and then adjusted to ensure its consistency with the other two partition coefficients (KOW and KOA). Although the indirect method carries theoretically twice as much error as the direct method, when the predicted values of KAW are then utilized as an input to the environmental fate model The OECD POV and LRTP Screening Tool, ver. 2.2, the indirect method elicits much higher and therefore much more restrictive values of overall persistence (POV) and transfer efficiency (TE) than its equivalent (direct method). High uncertainties related to the application of the direct method result mainly from the necessary adjustment procedure.

  12. Reliability testing of active SDHW components. Part II. Results of collector scaling tests and the effect on thermal performance from scale build-up

    SciTech Connect

    Bingham, C.E.; Farrington, R.B.

    1986-01-01

    The objective of this work was to determine how much scale accumulates in a flat-plate collector caused by repeated filling and draining. Laboratory testing of solar domestic hot water system components in FY 1983 showed that a significant amount of scale accumulated on draindown (drainout) valves, air vents, vacuum breakers, check valves subject to periodic draining on one side (such as when used as an isolation valve), and tempering valves. In FY 1984, we tested a flat-plate collector to measure the degree of scale accumulation caused by evaporation of water. Testing over a period of one year and 9733 cycles caused a 7% decrease in collector volume because of scale, which is equivalent to uniform scaling of 0.25 mm. A 1-mm scaling thickness would decrease the heat removal factor by 6% of increase the absorber plate temperature and overall heat loss factor U/sub L/ by 5/sup 0/C and 2%, respectively. This would result in a 13% reduction in the amount of energy collected. Homeowners in geographical areas where the water has a high potential for scaling should not use direct solar energy systems that use conventional flat-plate collectors unless they treat the water before it enters the system.

  13. Probabilistic Methods for Structural Design and Reliability

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Whitlow, Woodrow, Jr. (Technical Monitor)

    2002-01-01

    This report describes a formal method to quantify structural damage tolerance and reliability in the presence of a multitude of uncertainties in turbine engine components. The method is based at the material behavior level where primitive variables with their respective scatter ranges are used to describe behavior. Computational simulation is then used to propagate the uncertainties to the structural scale where damage tolerance and reliability are usually specified. Several sample cases are described to illustrate the effectiveness, versatility, and maturity of the method. Typical results from this method demonstrate, that it is mature and that it can be used to probabilistically evaluate turbine engine structural components. It may be inferred from the results that the method is suitable for probabilistically predicting the remaining life in aging or in deteriorating structures, for making strategic projections and plans, and for achieving better, cheaper, faster products that give competitive advantages in world markets.

  14. Optimal Implementations for Reliable Circadian Clocks

    NASA Astrophysics Data System (ADS)

    Hasegawa, Yoshihiko; Arita, Masanori

    2014-09-01

    Circadian rhythms are acquired through evolution to increase the chances for survival through synchronizing with the daylight cycle. Reliable synchronization is realized through two trade-off properties: regularity to keep time precisely, and entrainability to synchronize the internal time with daylight. We find by using a phase model with multiple inputs that achieving the maximal limit of regularity and entrainability entails many inherent features of the circadian mechanism. At the molecular level, we demonstrate the role sharing of two light inputs, phase advance and delay, as is well observed in mammals. At the behavioral level, the optimal phase-response curve inevitably contains a dead zone, a time during which light pulses neither advance nor delay the clock. We reproduce the results of phase-controlling experiments entrained by two types of periodic light pulses. Our results indicate that circadian clocks are designed optimally for reliable clockwork through evolution.

  15. Multi-virulence-locus sequence typing of Staphylococcus lugdunensis generates results consistent with a clonal population structure and is reliable for epidemiological typing.

    PubMed

    Didi, Jennifer; Lemée, Ludovic; Gibert, Laure; Pons, Jean-Louis; Pestel-Caron, Martine

    2014-10-01

    Staphylococcus lugdunensis is an emergent virulent coagulase-negative staphylococcus responsible for severe infections similar to those caused by Staphylococcus aureus. To understand its potentially pathogenic capacity and have further detailed knowledge of the molecular traits of this organism, 93 isolates from various geographic origins were analyzed by multi-virulence-locus sequence typing (MVLST), targeting seven known or putative virulence-associated loci (atlLR2, atlLR3, hlb, isdJ, SLUG_09050, SLUG_16930, and vwbl). The polymorphisms of the putative virulence-associated loci were moderate and comparable to those of the housekeeping genes analyzed by multilocus sequence typing (MLST). However, the MVLST scheme generated 43 virulence types (VTs) compared to 20 sequence types (STs) based on MLST, indicating that MVLST was significantly more discriminating (Simpson's index [D], 0.943). No hypervirulent lineage or cluster specific to carriage strains was defined. The results of multilocus sequence analysis of known and putative virulence-associated loci are consistent with a clonal population structure for S. lugdunensis, suggesting a coevolution of these genes with housekeeping genes. Indeed, the nonsynonymous to synonymous evolutionary substitutions (dN/dS) ratio, the Tajima's D test, and Single-likelihood ancestor counting (SLAC) analysis suggest that all virulence-associated loci were under negative selection, even atlLR2 (AtlL protein) and SLUG_16930 (FbpA homologue), for which the dN/dS ratios were higher. In addition, this analysis of virulence-associated loci allowed us to propose a trilocus sequence typing scheme based on the intragenic regions of atlLR3, isdJ, and SLUG_16930, which is more discriminant than MLST for studying short-term epidemiology and further characterizing the lineages of the rare but highly pathogenic S. lugdunensis.

  16. Multi-Virulence-Locus Sequence Typing of Staphylococcus lugdunensis Generates Results Consistent with a Clonal Population Structure and Is Reliable for Epidemiological Typing

    PubMed Central

    Didi, Jennifer; Lemée, Ludovic; Gibert, Laure; Pons, Jean-Louis

    2014-01-01

    Staphylococcus lugdunensis is an emergent virulent coagulase-negative staphylococcus responsible for severe infections similar to those caused by Staphylococcus aureus. To understand its potentially pathogenic capacity and have further detailed knowledge of the molecular traits of this organism, 93 isolates from various geographic origins were analyzed by multi-virulence-locus sequence typing (MVLST), targeting seven known or putative virulence-associated loci (atlLR2, atlLR3, hlb, isdJ, SLUG_09050, SLUG_16930, and vwbl). The polymorphisms of the putative virulence-associated loci were moderate and comparable to those of the housekeeping genes analyzed by multilocus sequence typing (MLST). However, the MVLST scheme generated 43 virulence types (VTs) compared to 20 sequence types (STs) based on MLST, indicating that MVLST was significantly more discriminating (Simpson's index [D], 0.943). No hypervirulent lineage or cluster specific to carriage strains was defined. The results of multilocus sequence analysis of known and putative virulence-associated loci are consistent with a clonal population structure for S. lugdunensis, suggesting a coevolution of these genes with housekeeping genes. Indeed, the nonsynonymous to synonymous evolutionary substitutions (dN/dS) ratio, the Tajima's D test, and Single-likelihood ancestor counting (SLAC) analysis suggest that all virulence-associated loci were under negative selection, even atlLR2 (AtlL protein) and SLUG_16930 (FbpA homologue), for which the dN/dS ratios were higher. In addition, this analysis of virulence-associated loci allowed us to propose a trilocus sequence typing scheme based on the intragenic regions of atlLR3, isdJ, and SLUG_16930, which is more discriminant than MLST for studying short-term epidemiology and further characterizing the lineages of the rare but highly pathogenic S. lugdunensis. PMID:25078912

  17. Reliability and Maintainability (RAM) Training

    NASA Technical Reports Server (NTRS)

    Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Packard, Michael H. (Editor)

    2000-01-01

    The theme of this manual is failure physics-the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low-cost reliable products. In a broader sense the manual should do more. It should underscore the urgent need CI for mature attitudes toward reliability. Five of the chapters were originally presented as a classroom course to over 1000 Martin Marietta engineers and technicians. Another four chapters and three appendixes have been added, We begin with a view of reliability from the years 1940 to 2000. Chapter 2 starts the training material with a review of mathematics and a description of what elements contribute to product failures. The remaining chapters elucidate basic reliability theory and the disciplines that allow us to control and eliminate failures.

  18. easyCBM Beginning Reading Measures: Grades K-1 Alternate Form Reliability and Criterion Validity with the SAT-10. Technical Report #1403

    ERIC Educational Resources Information Center

    Wray, Kraig; Lai, Cheng-Fei; Sáez, Leilani; Alonzo, Julie; Tindal, Gerald

    2013-01-01

    We report the results of an alternate form reliability and criterion validity study of kindergarten and grade 1 (N = 84-199) reading measures from the easyCBM© assessment system and Stanford Early School Achievement Test/Stanford Achievement Test, 10th edition (SESAT/SAT-­10) across 5 time points. The alternate form reliabilities ranged from…

  19. Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Mixed-Humid Climates; January 2006 - December 2006

    SciTech Connect

    Anderson, R.; Hendron, R.; Eastment, M.; Jalalzadeh-Azar, A.

    2006-12-01

    This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in the Mixed-Humid Climate Region on a cost-neutral basis.

  20. Building America Residential System Research Results. Achieving 30% Whole House Energy Savings Level in Hot-Dry and Mixed-Dry Climates

    SciTech Connect

    Anderson, R.; Hendron, R.; Eastment, M.; Jalalzadeh-Azar, A.

    2006-01-01

    This report summarizes Building America research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in the Hot-Dry/Mixed-Dry Climate Region on a cost-neutral basis.

  1. Software reliability report

    NASA Technical Reports Server (NTRS)

    Wilson, Larry

    1991-01-01

    There are many software reliability models which try to predict future performance of software based on data generated by the debugging process. Unfortunately, the models appear to be unable to account for the random nature of the data. If the same code is debugged multiple times and one of the models is used to make predictions, intolerable variance is observed in the resulting reliability predictions. It is believed that data replication can remove this variance in lab type situations and that it is less than scientific to talk about validating a software reliability model without considering replication. It is also believed that data replication may prove to be cost effective in the real world, thus the research centered on verification of the need for replication and on methodologies for generating replicated data in a cost effective manner. The context of the debugging graph was pursued by simulation and experimentation. Simulation was done for the Basic model and the Log-Poisson model. Reasonable values of the parameters were assigned and used to generate simulated data which is then processed by the models in order to determine limitations on their accuracy. These experiments exploit the existing software and program specimens which are in AIR-LAB to measure the performance of reliability models.

  2. Achieving Success in Small Business: A Self-Instruction Program for Small Business Owner-Managers. Developing Ads That Produce Results.

    ERIC Educational Resources Information Center

    Virginia Polytechnic Inst. and State Univ., Blacksburg. Div. of Vocational-Technical Education.

    This self-instructional module on developing ads that produce results is the sixth in a set of twelve modules designed for small business owner-managers. Competencies for this module are (1) identify three guidelines to be considered when you invest money in advertising, (2) identify the five basic elements of a printed advertisement, and (3)…

  3. COMPARISON BETWEEN THE RESULTS ACHIEVED IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH TWO KINDS OF AUTOLOGOUS GRAFTS: PATELLAR TENDON VERSUS SEMITENDINOUS AND GRACILIS

    PubMed Central

    Abdalla, Rene Jorge; Monteiro, Diego Antico; Dias, Leonardo; Correia, Dárcio Maurício; Cohen, Moisés; Forgas, Andrea

    2015-01-01

    Objective: this study aims to compare the arthrometric and isokinetic examination results from two types of autologous grafts: the central third of the patellar ligament and a graft formed by the tendons of the semitendinosus and gracilis muscles, within the same rehabilitation protocol, six months after the surgery. Methods: the results from examinations carried out on 63 patients were analyzed. These patients were divided in two groups: one group of 30 patients who received a patellar tendon graft and another group of 33 patients who received a graft from the tendons of the semitendinosus and gracilis muscles. Both the grafts were attached in the same way, with Endobutton™ for suspensory fixation to the femur and a bioabsorbable interference screw for fixation in the tibial tunnel. Results: arthrometry 30 did not present any statistical difference between the two study groups. On the other hand, the isokinetic evaluation showed that the patellar tendon group had a larger mean peak torque of flexion and greater extension deficit, while the semitendinosus/gracilis group had a better mean flexion/extension ratio and greater percentage of flexion deficit. There was no statistically significant difference between the groups when measuring peak torque extension. Conclusion: therefore, when the patellar tendon was used, there was greater extensor deficit and, when the semitendinosus/gracilis tendons were used, there was greater flexor deficit. PMID:27004173

  4. Reliability model generator

    NASA Technical Reports Server (NTRS)

    McMann, Catherine M. (Inventor); Cohen, Gerald C. (Inventor)

    1991-01-01

    An improved method and system for automatically generating reliability models for use with a reliability evaluation tool is described. The reliability model generator of the present invention includes means for storing a plurality of low level reliability models which represent the reliability characteristics for low level system components. In addition, the present invention includes means for defining the interconnection of the low level reliability models via a system architecture description. In accordance with the principles of the present invention, a reliability model for the entire system is automatically generated by aggregating the low level reliability models based on the system architecture description.

  5. Achievements and Challenges upon the Implementation of a Program for National Control of Congenital Chagas in Bolivia: Results 2004–2009

    PubMed Central

    Alonso-Vega, Cristina; Billot, Claire; Torrico, Faustino

    2013-01-01

    Bolivia is one of the most endemic countries for Chagas disease. Data of 2005 shows that incidence is around 1.09‰ inhabitants and seroprevalence in children under 15 ranged from 10% in urban areas to 40% in rural areas. In this article, we report results obtained during the implementation of the congenital Chagas program, one of the biggest casuistry in congenital Chagas disease, led by National Program of Chagas and Belgian cooperation from 2004 to 2009. The program strategy was based on serological results during pregnancy and on the follow up of children born from positive mothers until one year old; if positive, treatment was done with Benznidazole, 10 mg/Kg/day/30 days with one post treatment control 6 months later. Throughout the length of the program, a total of 318,479 pregnant women were screened and 23.31% were detected positive. 42,538 children born from positive mothers were analyzed at birth by micromethod, of which 1.43% read positive. 10,120 children returned for their second micromethod control of which 2.29% read positive, 7,650 children returned for the serological control, of which 3.32% turned out positive. From the 1,093 positive children, 70% completed the 30 day-treatment and 122 returned for post treatment control with 96% showing a negative result. It has been seen that maternal-fetal transmission rates vary between 2% and 4%, with an average of 2.6% (about half of previously reported studies that reached 5%). In this work, we show that it is possible to implement, with limited resources, a National Congenital Chagas Program and to integrate it into the Bolivian health system. Keys of success are population awareness, health personnel motivation, and political commitment at all levels. PMID:23875039

  6. Reliable measurement of the receding contact angle.

    PubMed

    Korhonen, Juuso T; Huhtamäki, Tommi; Ikkala, Olli; Ras, Robin H A

    2013-03-26

    Surface wettability is usually evaluated by the contact angle between the perimeter of a water drop and the surface. However, this single measurement is not enough for proper characterization, and the so-called advancing and receding contact angles also need to be measured. Measuring the receding contact angle can be challenging, especially for extremely hydrophobic surfaces. We demonstrate a reliable procedure by using the common needle-in-the-sessile-drop method. Generally, the contact line movement needs to be followed, and true receding movement has to be distinguished from "pseudo-movement" occurring before the receding angle is reached. Depending on the contact angle hysteresis, the initial size of the drop may need to be surprisingly large to achieve a reliable result. Although our motivation for this work was the characterization of superhydrophobic surfaces, we also show that this method works universally ranging from hydrophilic to superhydrophobic surfaces.

  7. Reliability Considerations for the Operation of Large Accelerator User Facilities

    SciTech Connect

    Willeke, F. J.

    2016-01-29

    The lecture provides an overview of considerations relevant for achieving highly reliable operation of accelerator based user facilities. The article starts with an overview of statistical reliability formalism which is followed by high reliability design considerations with examples. Finally, the article closes with operational aspects of high reliability such as preventive maintenance and spares inventory.

  8. Excellent therapeutic results achieved in chronic myeloid leukemia patients with front-line imatinib and early treatment modifications in suboptimal responders: a retrospective study on 91 unselected patients.

    PubMed

    Cerrano, Marco; Crisà, Elena; Pregno, Patrizia; Aguzzi, Chiara; Riccomagno, Paola; Boccadoro, Mario; Ferrero, Dario

    2013-10-01

    Second generation tyrosine kinase-inhibitors (TKI) have been claimed to represent now the first-choice therapy for chronic myeloid leukemia (CML). Indeed, they generally induce faster and deeper molecular responses compared to imatinib that, however, is equally effective in at least 50% of patients. Moreover, some recent reports have questioned the long term safety of dasatinib and nilotinib. Therefore, upfront imatinib with early shift to second generation TKI for patients with slow/incomplete response might be as effective as front-line second generation TKI, with a possibly better safety profile. We retrospectively evaluated 91 chronic phase CML patients (median follow-up 57 months, median age 61 years), treated front-line with standard-dose imatinib and early therapy modifications (at 3-12 months) in case of unsatisfactory response or intolerance. Thirty-three patients (24 with unsatisfactory response, 9 intolerant) changed therapy, either by increasing imatinib dose (11/91) or by switching to second generation TKI (22 directly, 4 after high-dose imatinib). Globally, our strategy led to complete cytogenetic response (CCyR) in 98% of the patients, major molecular response (MMR) in 88% and molecular response 4 logs (MR(4.0) ) in 62%. Three patients in CCyR (3%), 2 of them in MMR too, suddenly progressed to blastic phase. At the last follow-up nine patients had died, seven of CML-unrelated causes and two only of CML progression. These results suggest that our strategy could be as effective as front line second generation TKI, with most of patients still receiving imatinib, a drug of better known long-term side effects and lower cost.

  9. Epistemological Beliefs and Academic Achievement

    ERIC Educational Resources Information Center

    Arslantas, Halis Adnan

    2016-01-01

    This study aimed to identify the relationship between teacher candidates' epistemological beliefs and academic achievement. The participants of the study were 353 teacher candidates studying their fourth year at the Education Faculty. The Epistemological Belief Scale was used which adapted to Turkish through reliability and validity work by…

  10. Stirling Convertor Fasteners Reliability Quantification

    NASA Technical Reports Server (NTRS)

    Shah, Ashwin R.; Korovaichuk, Igor; Kovacevich, Tiodor; Schreiber, Jeffrey G.

    2006-01-01

    Onboard Radioisotope Power Systems (RPS) being developed for NASA s deep-space science and exploration missions require reliable operation for up to 14 years and beyond. Stirling power conversion is a candidate for use in an RPS because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced inventory of radioactive material. Structural fasteners are responsible to maintain structural integrity of the Stirling power convertor, which is critical to ensure reliable performance during the entire mission. Design of fasteners involve variables related to the fabrication, manufacturing, behavior of fasteners and joining parts material, structural geometry of the joining components, size and spacing of fasteners, mission loads, boundary conditions, etc. These variables have inherent uncertainties, which need to be accounted for in the reliability assessment. This paper describes these uncertainties along with a methodology to quantify the reliability, and provides results of the analysis in terms of quantified reliability and sensitivity of Stirling power conversion reliability to the design variables. Quantification of the reliability includes both structural and functional aspects of the joining components. Based on the results, the paper also describes guidelines to improve the reliability and verification testing.

  11. Reliability Generalization: "Lapsus Linguae"

    ERIC Educational Resources Information Center

    Smith, Julie M.

    2011-01-01

    This study examines the proposed Reliability Generalization (RG) method for studying reliability. RG employs the application of meta-analytic techniques similar to those used in validity generalization studies to examine reliability coefficients. This study explains why RG does not provide a proper research method for the study of reliability,…

  12. Higher Education Counts: Achieving Results. 2009 Report

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2009

    2009-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's state system of higher education, as required under Connecticut General Statutes Section 10a-6a. The report contains accountability measures developed through the Performance Measures Task Force and approved by the Board of Governors for Higher Education. The…

  13. Higher Education Counts: Achieving Results. 2006 Report

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2006

    2006-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's state system of higher education, as required under Connecticut General Statutes Section 10a-6a. The report contains accountability measures developed through the Performance Measures Task Force and approved by the Board of Governors for Higher Education. The…

  14. Higher Education Counts: Achieving Results. 2008 Report

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2008

    2008-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's state system of higher education, as required under Connecticut General Statutes Section 10a-6a. The report contains accountability measures developed through the Performance Measures Task Force and approved by the Board of Governors for Higher Education. The…

  15. Higher Education Counts: Achieving Results. 2007 Report

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2007

    2007-01-01

    "Higher Education Counts" is the annual accountability report on Connecticut's state system of higher education, as required under Connecticut General Statutes Section 10a-6a. The report contains accountability measures developed through the Performance Measures Task Force and approved by the Board of Governors for Higher Education. The…

  16. Converting customer expectations into achievable results.

    PubMed

    Landis, G A

    1999-11-01

    It is not enough in today's environment to just meet customers' expectations--we must exceed them. Therefore, one must learn what constitutes expectations. These needs have expanded during the past few years from just manufacturing the product and looking at the outcome from a provincial standpoint. Now we must understand and satisfy the entire supply chain. To manage this process and satisfy the customer, the process now involves the supplier, the manufacturer, and the entire distribution system.

  17. Higher Education Counts: Achieving Results, 2011. Report

    ERIC Educational Resources Information Center

    Connecticut Department of Higher Education (NJ1), 2011

    2011-01-01

    This report, issued by the Connecticut Department of Higher Education, reports on trends in higher education for the year 2011. Six goals are presented, each with at least two indicators. Each indicator is broken down into the following subsections: About This Indicator; Highlights; and In the Future. Most indicators also include statistical…

  18. Can There Be Reliability without "Reliability?"

    ERIC Educational Resources Information Center

    Mislevy, Robert J.

    2004-01-01

    An "Educational Researcher" article by Pamela Moss (1994) asks the title question, "Can there be validity without reliability?" Yes, she answers, if by reliability one means "consistency among independent observations intended as interchangeable" (Moss, 1994, p. 7), quantified by internal consistency indices such as…

  19. Human Capital: Building the Information Technology Workforce To Achieve Results. Testimony before the Subcommittee on Technology and Procurement Policy, Committee on Government Reform, U.S. House of Representatives.

    ERIC Educational Resources Information Center

    Walker, David M.

    The Comptroller General of the United States testified before Congress regarding the General Accounting Office's (GAO's) framework for building the information technology (IT) work force to achieve results. The following were among the key points of his testimony: (1) the federal government is facing pervasive human capital challenges that are…

  20. Preliminary study of the reliability of imaging charge coupled devices

    NASA Technical Reports Server (NTRS)

    Beall, J. R.; Borenstein, M. D.; Homan, R. A.; Johnson, D. L.; Wilson, D. D.; Young, V. F.

    1978-01-01

    Imaging CCDs are capable of low light level response and high signal-to-noise ratios. In space applications they offer the user the ability to achieve extremely high resolution imaging with minimum circuitry in the photo sensor array. This work relates the CCD121H Fairchild device to the fundamentals of CCDs and the representative technologies. Several failure modes are described, construction is analyzed and test results are reported. In addition, the relationship of the device reliability to packaging principles is analyzed and test data presented. Finally, a test program is defined for more general reliability evaluation of CCDs.

  1. Comparison of reliability performance of group connected and conventional HVDC transmission systems

    SciTech Connect

    Kuruganty, S.

    1995-10-01

    A group connected HVDC transmission scheme is a variant of the unit connection where instead of a single generator, a group of generators are directly connected to the converter. Studies conducted in the past indicated that significant cost reduction can be achieved using this scheme. This is mainly due to the elimination of many components which results in considerable capital and operating cost savings to the utility. Concerns regarding the reliability performance of unit connected schemes were raised, however, there has not been a detailed reliability study conducted. This paper addresses the reliability evaluation aspect of a group connected scheme and compares the reliability performance of the group connected scheme with that of the conventional common collector system. Reliability models for both schemes were developed using a hypothetical system model based on the Nelson River system. Practical system component outage data was used to examine the reliability performance of both schemes.

  2. Multiple objective optimization in reliability demonstration test

    SciTech Connect

    Lu, Lu; Anderson-Cook, Christine Michaela; Li, Mingyang

    2016-10-01

    Reliability demonstration tests are usually performed in product design or validation processes to demonstrate whether a product meets specified requirements on reliability. For binomial demonstration tests, the zero-failure test has been most commonly used due to its simplicity and use of minimum sample size to achieve an acceptable consumer’s risk level. However, this test can often result in unacceptably high risk for producers as well as a low probability of passing the test even when the product has good reliability. This paper explicitly explores the interrelationship between multiple objectives that are commonly of interest when planning a demonstration test and proposes structured decision-making procedures using a Pareto front approach for selecting an optimal test plan based on simultaneously balancing multiple criteria. Different strategies are suggested for scenarios with different user priorities and graphical tools are developed to help quantify the trade-offs between choices and to facilitate informed decision making. As a result, potential impacts of some subjective user inputs on the final decision are studied to offer insights and useful guidance for general applications.

  3. Improve filtration for optimum equipment reliability

    SciTech Connect

    Cervera, S.M.

    1996-01-01

    The introduction 20 years ago of the American Petroleum Institute Standard API-614 as a purchase specification for lubrication, shaft sealing and control oil systems, had a considerable impact and did much to improve system reliability at that time. Today, however, these recommendations regarding filter rating and flushing cleanliness are outdated. Much research in the tribology field correlates clearance size particulate contamination with accelerated component wear, fatigue and performance degradation. Some of these studies demonstrate that by decreasing the population of clearance size particulate in lubrication oils, component life increases exponentially. Knowing the dynamic clearances of a piece of machinery makes it possible, using the ISO 4406 Cleanliness Code, to determine what cleanliness level will minimize contamination-related component wear/fatigue and thus help optimize machinery performance and reliability. Data obtained by the author through random sampling of rotating equipment lube and seal oil systems indicate that the API-614 standard, as it pertains to filtration and flushing, is insufficient to ensure that particulate contamination is maintained to within the levels necessary to achieve optimum equipment reliability and safety, without increasing operating cost. Adopting and practicing the guidelines presented should result in the following benefits: (1) the frequency of bearing, oil pump, mechanical seal, fluid coupling, gearbox and hydraulic control valve failures would be minimized; (2) the mean time between planned maintenance (MTBPM) would be increased. The result will be a substantial increase in safety and cost savings to the operator.

  4. Multiple objective optimization in reliability demonstration test

    DOE PAGES

    Lu, Lu; Anderson-Cook, Christine Michaela; Li, Mingyang

    2016-10-01

    Reliability demonstration tests are usually performed in product design or validation processes to demonstrate whether a product meets specified requirements on reliability. For binomial demonstration tests, the zero-failure test has been most commonly used due to its simplicity and use of minimum sample size to achieve an acceptable consumer’s risk level. However, this test can often result in unacceptably high risk for producers as well as a low probability of passing the test even when the product has good reliability. This paper explicitly explores the interrelationship between multiple objectives that are commonly of interest when planning a demonstration test andmore » proposes structured decision-making procedures using a Pareto front approach for selecting an optimal test plan based on simultaneously balancing multiple criteria. Different strategies are suggested for scenarios with different user priorities and graphical tools are developed to help quantify the trade-offs between choices and to facilitate informed decision making. As a result, potential impacts of some subjective user inputs on the final decision are studied to offer insights and useful guidance for general applications.« less

  5. Calculating system reliability with SRFYDO

    SciTech Connect

    Morzinski, Jerome; Anderson - Cook, Christine M; Klamann, Richard M

    2010-01-01

    SRFYDO is a process for estimating reliability of complex systems. Using information from all applicable sources, including full-system (flight) data, component test data, and expert (engineering) judgment, SRFYDO produces reliability estimates and predictions. It is appropriate for series systems with possibly several versions of the system which share some common components. It models reliability as a function of age and up to 2 other lifecycle (usage) covariates. Initial output from its Exploratory Data Analysis mode consists of plots and numerical summaries so that the user can check data entry and model assumptions, and help determine a final form for the system model. The System Reliability mode runs a complete reliability calculation using Bayesian methodology. This mode produces results that estimate reliability at the component, sub-system, and system level. The results include estimates of uncertainty, and can predict reliability at some not-too-distant time in the future. This paper presents an overview of the underlying statistical model for the analysis, discusses model assumptions, and demonstrates usage of SRFYDO.

  6. Applicability and Limitations of Reliability Allocation Methods

    NASA Technical Reports Server (NTRS)

    Cruz, Jose A.

    2016-01-01

    Reliability allocation process may be described as the process of assigning reliability requirements to individual components within a system to attain the specified system reliability. For large systems, the allocation process is often performed at different stages of system design. The allocation process often begins at the conceptual stage. As the system design develops, more information about components and the operating environment becomes available, different allocation methods can be considered. Reliability allocation methods are usually divided into two categories: weighting factors and optimal reliability allocation. When properly applied, these methods can produce reasonable approximations. Reliability allocation techniques have limitations and implied assumptions that need to be understood by system engineers. Applying reliability allocation techniques without understanding their limitations and assumptions can produce unrealistic results. This report addresses weighting factors, optimal reliability allocation techniques, and identifies the applicability and limitations of each reliability allocation technique.

  7. Reliability analysis framework for computer-assisted medical decision systems

    SciTech Connect

    Habas, Piotr A.; Zurada, Jacek M.; Elmaghraby, Adel S.; Tourassi, Georgia D.

    2007-02-15

    We present a technique that enhances computer-assisted decision (CAD) systems with the ability to assess the reliability of each individual decision they make. Reliability assessment is achieved by measuring the accuracy of a CAD system with known cases similar to the one in question. The proposed technique analyzes the feature space neighborhood of the query case to dynamically select an input-dependent set of known cases relevant to the query. This set is used to assess the local (query-specific) accuracy of the CAD system. The estimated local accuracy is utilized as a reliability measure of the CAD response to the query case. The underlying hypothesis of the study is that CAD decisions with higher reliability are more accurate. The above hypothesis was tested using a mammographic database of 1337 regions of interest (ROIs) with biopsy-proven ground truth (681 with masses, 656 with normal parenchyma). Three types of decision models, (i) a back-propagation neural network (BPNN), (ii) a generalized regression neural network (GRNN), and (iii) a support vector machine (SVM), were developed to detect masses based on eight morphological features automatically extracted from each ROI. The performance of all decision models was evaluated using the Receiver Operating Characteristic (ROC) analysis. The study showed that the proposed reliability measure is a strong predictor of the CAD system's case-specific accuracy. Specifically, the ROC area index for CAD predictions with high reliability was significantly better than for those with low reliability values. This result was consistent across all decision models investigated in the study. The proposed case-specific reliability analysis technique could be used to alert the CAD user when an opinion that is unlikely to be reliable is offered. The technique can be easily deployed in the clinical environment because it is applicable with a wide range of classifiers regardless of their structure and it requires neither additional

  8. Human Reliability Program Overview

    SciTech Connect

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  9. What is the reliability of non-trained investigators in recognising structural MRI lesions of sacroiliac joints in patients with recent inflammatory back pain? Results of the DESIR cohort

    PubMed Central

    Jacquemin, Charlotte; Rubio Vargas, Roxana; van den Berg, Rosaline; Thévenin, Fabrice; Lenczner, Gregory; Reijnierse, Monique; Ferkal, Salah; Le Corvoisier, Philippe; Rahmouni, Alain; Loeuille, Damien; Feydy, Antoine; Dougados, Maxime; van der Heijde, Désirée; Claudepierre, Pascal

    2016-01-01

    Objective The objective of this study was to evaluate the reliability of recognising structural lesions on MRI (erosions, fatty lesions, ankylosis) of the sacroiliac joints (MRI-SIJ) in clinical practice compared to a central reading in patients with a possible recent axial spondyloarthritis (axSpA). Methods Patients aged 18–50 years, with recent (<3 years) and chronic (≥3 months) inflammatory back pain, suggestive of axSpA were included in the DEvenir des Spondyloarthrites Indifférenciées Récentes (DESIR) cohort. MRI-SIJ structural lesions were scored by non-trained local readers, and by two trained central readers. Local readers scored each SIJ as normal, doubtful or definite lesions. Central readers scored separately each type of lesion. The central reading (mean of the two central readers’ scores) was the external standard. Agreement (κ) was calculated first between local (3 definitions of a positive MRI-SIJ) and central readings (9 definitions), and then between the two central readers. Results 664/708 patients with complete available images were included. Agreements between local and central readings were overall ‘fair’, except when considering at least 2 or 3 fatty lesions and at least 3 erosions and/or fatty lesions where agreement was ‘moderate’. Agreement between central readers was similar. MRI-SIJ was positive for 52.6% of patients according to central reading (at least 1 structural lesion) and for 35.4% of patients according to local reading (at least unilateral ‘doubtful‘ or ‘definite’ structural lesions). Conclusions Agreement on a positive structural MRI-SIJ was fair to moderate between local and central readings, as well as between central readers. The reliability improved when fatty lesions were considered. Trial registration number NCTO 164 8907. PMID:27933207

  10. Integrated avionics reliability

    NASA Technical Reports Server (NTRS)

    Alikiotis, Dimitri

    1988-01-01

    The integrated avionics reliability task is an effort to build credible reliability and/or performability models for multisensor integrated navigation and flight control. The research was initiated by the reliability analysis of a multisensor navigation system consisting of the Global Positioning System (GPS), the Long Range Navigation system (Loran C), and an inertial measurement unit (IMU). Markov reliability models were developed based on system failure rates and mission time.

  11. Reliable Design Versus Trust

    NASA Technical Reports Server (NTRS)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    This presentation focuses on reliability and trust for the users portion of the FPGA design flow. It is assumed that the manufacturer prior to hand-off to the user tests FPGA internal components. The objective is to present the challenges of creating reliable and trusted designs. The following will be addressed: What makes a design vulnerable to functional flaws (reliability) or attackers (trust)? What are the challenges for verifying a reliable design versus a trusted design?

  12. Reliability and structural integrity

    NASA Technical Reports Server (NTRS)

    Davidson, J. R.

    1976-01-01

    An analytic model is developed to calculate the reliability of a structure after it is inspected for cracks. The model accounts for the growth of undiscovered cracks between inspections and their effect upon the reliability after subsequent inspections. The model is based upon a differential form of Bayes' Theorem for reliability, and upon fracture mechanics for crack growth.

  13. Reliability model generator specification

    NASA Technical Reports Server (NTRS)

    Cohen, Gerald C.; Mccann, Catherine

    1990-01-01

    The Reliability Model Generator (RMG), a program which produces reliability models from block diagrams for ASSIST, the interface for the reliability evaluation tool SURE is described. An account is given of motivation for RMG and the implemented algorithms are discussed. The appendices contain the algorithms and two detailed traces of examples.

  14. Viking Lander reliability program

    NASA Technical Reports Server (NTRS)

    Pilny, M. J.

    1978-01-01

    The Viking Lander reliability program is reviewed with attention given to the development of the reliability program requirements, reliability program management, documents evaluation, failure modes evaluation, production variation control, failure reporting and correction, and the parts program. Lander hardware failures which have occurred during the mission are listed.

  15. Theory of reliable systems

    NASA Technical Reports Server (NTRS)

    Meyer, J. F.

    1975-01-01

    An attempt was made to refine the current notion of system reliability by identifying and investigating attributes of a system which are important to reliability considerations. Techniques which facilitate analysis of system reliability are included. Special attention was given to fault tolerance, diagnosability, and reconfigurability characteristics of systems.

  16. Predicting software reliability

    NASA Technical Reports Server (NTRS)

    Littlewood, B.

    1989-01-01

    A detailed look is given to software reliability techniques. A conceptual model of the failure process is examined, and some software reliability growth models are discussed. Problems for which no current solutions exist are addressed, emphasizing the very difficult problem of safety-critical systems for which the reliability requirements can be enormously demanding.

  17. Reliability assurance for regulation of advanced reactors

    SciTech Connect

    Fullwood, R.; Lofaro, R.; Samanta, P.

    1991-12-31

    The advanced nuclear power plants must achieve higher levels of safety than the first generation of plants. Showing that this is indeed true provides new challenges to reliability and risk assessment methods in the analysis of the designs employing passive and semi-passive protection. Reliability assurance of the advanced reactor systems is important for determining the safety of the design and for determining the plant operability. Safety is the primary concern, but operability is considered indicative of good and safe operation. This paper discusses several concerns for reliability assurance of the advanced design encompassing reliability determination, level of detail required in advanced reactor submittals, data for reliability assurance, systems interactions and common cause effects, passive component reliability, PRA-based configuration control system, and inspection, training, maintenance and test requirements. Suggested approaches are provided for addressing each of these topics.

  18. PV Systems Reliability Final Technical Report.

    SciTech Connect

    Lavrova, Olga; Flicker, Jack David; Johnson, Jay; Armijo, Kenneth Miguel; Gonzalez, Sigifredo; Schindelholz, Eric John; Sorensen, Neil R.; Yang, Benjamin Bing-Yeh

    2015-12-01

    The continued exponential growth of photovoltaic technologies paves a path to a solar-powered world, but requires continued progress toward low-cost, high-reliability, high-performance photovoltaic (PV) systems. High reliability is an essential element in achieving low-cost solar electricity by reducing operation and maintenance (O&M) costs and extending system lifetime and availability, but these attributes are difficult to verify at the time of installation. Utilities, financiers, homeowners, and planners are demanding this information in order to evaluate their financial risk as a prerequisite to large investments. Reliability research and development (R&D) is needed to build market confidence by improving product reliability and by improving predictions of system availability, O&M cost, and lifetime. This project is focused on understanding, predicting, and improving the reliability of PV systems. The two areas being pursued include PV arc-fault and ground fault issues, and inverter reliability.

  19. Reliability-based lifetime maintenance of aging highway bridges

    NASA Astrophysics Data System (ADS)

    Enright, Michael P.; Frangopol, Dan M.

    2000-06-01

    As the nation's infrastructure continues to age, the cost of maintaining it at an acceptable safety level continues to increase. In the United States, about one of every three bridges is rated structurally deficient and/or functionally obsolete. It will require about 80 billion to eliminate the current backlog of bridge deficiencies and maintain repair levels. Unfortunately, the financial resources allocated for these activities fall extremely short of the demand. Although several existing and emerging NDT techniques are available to gather inspection data, current maintenance planning decisions for deficient bridges are based on data from subjective condition assessments and do not consider the reliability of bridge components and systems. Recently, reliability-based optimum maintenance planning strategies have been developed. They can be used to predict inspection and repair times to achieve minimum life-cycle cost of deteriorating structural systems. In this study, a reliability-based methodology which takes into account loading randomness and history, and randomness in strength and degradation resulting from aggressive environmental factors, is used to predict the time- dependent reliability of aging highway bridges. A methodology for incorporating inspection data into reliability predictions is also presented. Finally, optimal lifetime maintenance strategies are identified, in which optimal inspection/repair times are found based on minimum expected life-cycle cost under prescribed reliability constraints. The influence of discount rate on optimum solutions is evaluated.

  20. Multi-mode reliability-based design of horizontal curves.

    PubMed

    Essa, Mohamed; Sayed, Tarek; Hussein, Mohamed

    2016-08-01

    Recently, reliability analysis has been advocated as an effective approach to account for uncertainty in the geometric design process and to evaluate the risk associated with a particular design. In this approach, a risk measure (e.g. probability of noncompliance) is calculated to represent the probability that a specific design would not meet standard requirements. The majority of previous applications of reliability analysis in geometric design focused on evaluating the probability of noncompliance for only one mode of noncompliance such as insufficient sight distance. However, in many design situations, more than one mode of noncompliance may be present (e.g. insufficient sight distance and vehicle skidding at horizontal curves). In these situations, utilizing a multi-mode reliability approach that considers more than one failure (noncompliance) mode is required. The main objective of this paper is to demonstrate the application of multi-mode (system) reliability analysis to the design of horizontal curves. The process is demonstrated by a case study of Sea-to-Sky Highway located between Vancouver and Whistler, in southern British Columbia, Canada. Two noncompliance modes were considered: insufficient sight distance and vehicle skidding. The results show the importance of accounting for several noncompliance modes in the reliability model. The system reliability concept could be used in future studies to calibrate the design of various design elements in order to achieve consistent safety levels based on all possible modes of noncompliance.

  1. Load Control System Reliability

    SciTech Connect

    Trudnowski, Daniel

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  2. The causal ordering of mathematics anxiety and mathematics achievement: a longitudinal panel analysis.

    PubMed

    Ma, X; Xu, Jiangmin; Xu, Jiangming

    2004-04-01

    Using data from the Longitudinal Study of American Youth (LSAY), we aimed to determine the causal ordering between mathematics anxiety and mathematics achievement. Results of structural equation modelling showed that, across the entire junior and senior high school, prior low mathematics achievement significantly related to later high mathematics anxiety, but prior high mathematics anxiety hardly related to later low mathematics achievement. Mathematics achievement was more reliably stable from year to year than mathematics anxiety. There were statistically significant gender differences in the causal ordering between mathematics anxiety and mathematics achievement. Prior low mathematics achievement significantly related to later high mathematics anxiety for boys across the entire junior and senior high school but for girls at critical transition points only. Mathematics anxiety was more reliably stable from year to year among girls than among boys.

  3. Reliable Entanglement Verification

    NASA Astrophysics Data System (ADS)

    Arrazola, Juan; Gittsovich, Oleg; Donohue, John; Lavoie, Jonathan; Resch, Kevin; Lütkenhaus, Norbert

    2013-05-01

    Entanglement plays a central role in quantum protocols. It is therefore important to be able to verify the presence of entanglement in physical systems from experimental data. In the evaluation of these data, the proper treatment of statistical effects requires special attention, as one can never claim to have verified the presence of entanglement with certainty. Recently increased attention has been paid to the development of proper frameworks to pose and to answer these type of questions. In this work, we apply recent results by Christandl and Renner on reliable quantum state tomography to construct a reliable entanglement verification procedure based on the concept of confidence regions. The statements made do not require the specification of a prior distribution nor the assumption of an independent and identically distributed (i.i.d.) source of states. Moreover, we develop efficient numerical tools that are necessary to employ this approach in practice, rendering the procedure ready to be employed in current experiments. We demonstrate this fact by analyzing the data of an experiment where photonic entangled two-photon states were generated and whose entanglement is verified with the use of an accessible nonlinear witness.

  4. Improvement of the Reliability of Dielectrics for MLCC

    NASA Astrophysics Data System (ADS)

    Nakamura, Tomoyuki; Yao, Takayuki; Ikeda, Jun; Kubodera, Noriyuki; Takagi, Hiroshi

    2011-10-01

    To achieve enough reliability of monolithic ceramic capacitor, it is important to know the contribution of grain boundary and grain interior to its reliability and insulation resistance. As the number of grain boundaries per layer increased, mean time to failure (MTTF) increased. In addition, as the number of grain boundaries per layer increased, samples showed lower current leakage in the measured electric field range. Using these data, the grain boundary E-J curves were determined by simulation. As a result, temperature and electric field dependence of insulation resistance of grain boundary were very low. The insulation characteristics of one BaTiO3 grain per layer were examined. The resistance and reliability of grain interior were very low. To improve the degradation resistance of grain interior, Ca-doped BaTiO3-based dielectrics were developed. The influence of Ca substitution on MTTF was investigated and it was found out that MTTF increased with the increase of Ca substitution.

  5. Human Reliability Analysis for Design: Using Reliability Methods for Human Factors Issues

    SciTech Connect

    Ronald Laurids Boring

    2010-11-01

    This paper reviews the application of human reliability analysis methods to human factors design issues. An application framework is sketched in which aspects of modeling typically found in human reliability analysis are used in a complementary fashion to the existing human factors phases of design and testing. The paper provides best achievable practices for design, testing, and modeling. Such best achievable practices may be used to evaluate and human system interface in the context of design safety certifications.

  6. Six Motivational Reasons for Low School Achievement

    ERIC Educational Resources Information Center

    Reiss, Steven

    2009-01-01

    Reiss ("The normal personality: a new way of thinking about people." Cambridge University Press, New York, 2008) empirically derived a reliable and valid taxonomy of 16 life motives ("psychological needs"). The model suggests six motivational reasons for low achievement in school. Low achievement may be motivated by fear of failure (high need for…

  7. Achievement Motivation of Women: Effects of Achievement and Affiliation Arousal.

    ERIC Educational Resources Information Center

    Gama, Elizabeth Maria Pinheiro

    1985-01-01

    Assigned 139 Brazilian women to neutral, affiliation arousal, and achievement arousal conditions based on their levels of achievement (Ach) and affiliative (Aff) needs. Results of story analyses revealed that achievement arousal increased scores of high Ach subjects and that high Aff subjects obtained higher scores than low Aff subjects. (BL)

  8. Increasing Male Academic Achievement

    ERIC Educational Resources Information Center

    Jackson, Barbara Talbert

    2008-01-01

    The No Child Left Behind legislation has brought greater attention to the academic performance of American youth. Its emphasis on student achievement requires a closer analysis of assessment data by school districts. To address the findings, educators must seek strategies to remedy failing results. In a mid-Atlantic district of the Unites States,…

  9. Essays on Educational Achievement

    ERIC Educational Resources Information Center

    Ampaabeng, Samuel Kofi

    2013-01-01

    This dissertation examines the determinants of student outcomes--achievement, attainment, occupational choices and earnings--in three different contexts. The first two chapters focus on Ghana while the final chapter focuses on the US state of Massachusetts. In the first chapter, I exploit the incidence of famine and malnutrition that resulted to…

  10. 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.

  11. A study of the longevity and operational reliability of Goddard Spacecraft, 1960-1980

    NASA Technical Reports Server (NTRS)

    Shockey, E. F.

    1981-01-01

    Compiled data regarding the design lives and lifetimes actually achieved by 104 orbiting satellites launched by the Goddard Spaceflight Center between the years 1960 and 1980 is analyzed. Historical trends over the entire 21 year period are reviewed, and the more recent data is subjected to an examination of several key parameters. An empirical reliability function is derived, and compared with various mathematical models. Data from related studies is also discussed. The results provide insight into the reliability history of Goddard spacecraft an guidance for estimating the reliability of future programs.

  12. Characterizing reliability in a product/process design-assurance program

    SciTech Connect

    Kerscher, W.J. III; Booker, J.M.; Bement, T.R.; Meyer, M.A.

    1997-10-01

    Over the years many advancing techniques in the area of reliability engineering have surfaced in the military sphere of influence, and one of these techniques is Reliability Growth Testing (RGT). Private industry has reviewed RGT as part of the solution to their reliability concerns, but many practical considerations have slowed its implementation. It`s objective is to demonstrate the reliability requirement of a new product with a specified confidence. This paper speaks directly to that objective but discusses a somewhat different approach to achieving it. Rather than conducting testing as a continuum and developing statistical confidence bands around the results, this Bayesian updating approach starts with a reliability estimate characterized by large uncertainty and then proceeds to reduce the uncertainty by folding in fresh information in a Bayesian framework.

  13. Improving Search Engine Reliability

    NASA Astrophysics Data System (ADS)

    Pruthi, Jyoti; Kumar, Ela

    2010-11-01

    Search engines on the Internet are used daily to access and find information. While these services are providing an easy way to find information globally, they are also suffering from artificially created false results. This paper describes two techniques that are being used to manipulate the search engines: spam pages (used to achieve higher rankings on the result page) and cloaking (used to feed falsified data into search engines). This paper also describes two proposed methods to fight this kind of misuse, algorithms for both of the formerly mentioned cases of spamdexing.

  14. Metrological Reliability of Medical Devices

    NASA Astrophysics Data System (ADS)

    Costa Monteiro, E.; Leon, L. F.

    2015-02-01

    The prominent development of health technologies of the 20th century triggered demands for metrological reliability of physiological measurements comprising physical, chemical and biological quantities, essential to ensure accurate and comparable results of clinical measurements. In the present work, aspects concerning metrological reliability in premarket and postmarket assessments of medical devices are discussed, pointing out challenges to be overcome. In addition, considering the social relevance of the biomeasurements results, Biometrological Principles to be pursued by research and innovation aimed at biomedical applications are proposed, along with the analysis of their contributions to guarantee the innovative health technologies compliance with the main ethical pillars of Bioethics.

  15. Is entheses ultrasound reliable? A reading Latin American exercise.

    PubMed

    Ventura-Ríos, L; Navarro-Compan, V; Aliste, M; Linares, M Alva; Areny, R; Audisio, M; Bertoli, A M; Cazenave, T; Cerón, C; Díaz, M E; Gutiérrez, M; Hernández, C; Navarta, D A; Pineda, C; Py, G E; Reginato, A M; Rosa, J; Saaibi, D L; Sedano, O; Solano, C; Castillo-Gallego, C; Falçao, S; De Miguel, E

    2016-05-01

    The objective of this study is to evaluate inter-reader entheses ultrasound (US) reliability and the influence of the type of image or degree of sonographer experience on US reliability in patients with spondyloarthritis (SpA). Eighteen Latin American ultrasonographers with different experience took part in an US reading exercise evaluating 60 entheseal images (50 % static images and 50 % videos) from healthy controls and SpA patients. The following sonographic lesions were assessed: structure, thickness, bone proliferation/tendon calcification, erosions, bursitis, and Doppler signal. Another group of three experts with significant experience in entheses US read all images too. Inter-reader reliability among participants and experts was calculated by the Cohen's kappa coefficient. Thresholds for kappa values were <0.2 poor, 0.21-0.4 fair, 0.41-0.6 moderate, 0.61-0.8 good, and 0.81-1 excellent. Furthermore, the results for the expert group were stratified based on the type of image. Kappa correlation coefficients among participants, showed variability depending on the type of lesion, being fair for structure and thickness, moderate for calcifications, erosions, and bursitis, and excellent for Doppler signal. Inter-reader reliability among experts was higher, being moderate for structure and thickness, good for calcifications and bursitis, and excellent for erosions and Doppler. Inter-reader reliability for assessing calcification and structure using static images was significantly higher than for videos. Overall inter-reader reliability for assessing entheses by US in SpA is moderate to excellent for most of the lesions. However, special training seems fundamental to achieve better inter-reader reliability. Moreover, the type of image influenced these results, where evaluation of entheses by videos was more difficult than by static images.

  16. Graded Achievement, Tested Achievement, and Validity

    ERIC Educational Resources Information Center

    Brookhart, Susan M.

    2015-01-01

    Twenty-eight studies of grades, over a century, were reviewed using the argument-based approach to validity suggested by Kane as a theoretical framework. The review draws conclusions about the meaning of graded achievement, its relation to tested achievement, and changes in the construct of graded achievement over time. "Graded…

  17. Closing the achievement gap through modification of neurocognitive and neuroendocrine function: results from a cluster randomized controlled trial of an innovative approach to the education of children in kindergarten.

    PubMed

    Blair, Clancy; Raver, C Cybele

    2014-01-01

    Effective early education is essential for academic achievement and positive life outcomes, particularly for children in poverty. Advances in neuroscience suggest that a focus on self-regulation in education can enhance children's engagement in learning and establish beneficial academic trajectories in the early elementary grades. Here, we experimentally evaluate an innovative approach to the education of children in kindergarten that embeds support for self-regulation, particularly executive functions, into literacy, mathematics, and science learning activities. Results from a cluster randomized controlled trial involving 29 schools, 79 classrooms, and 759 children indicated positive effects on executive functions, reasoning ability, the control of attention, and levels of salivary cortisol and alpha amylase. Results also demonstrated improvements in reading, vocabulary, and mathematics at the end of kindergarten that increased into the first grade. A number of effects were specific to high-poverty schools, suggesting that a focus on executive functions and associated aspects of self-regulation in early elementary education holds promise for closing the achievement gap.

  18. Closing the Achievement Gap through Modification of Neurocognitive and Neuroendocrine Function: Results from a Cluster Randomized Controlled Trial of an Innovative Approach to the Education of Children in Kindergarten

    PubMed Central

    Blair, Clancy; Raver, C. Cybele

    2014-01-01

    Effective early education is essential for academic achievement and positive life outcomes, particularly for children in poverty. Advances in neuroscience suggest that a focus on self-regulation in education can enhance children’s engagement in learning and establish beneficial academic trajectories in the early elementary grades. Here, we experimentally evaluate an innovative approach to the education of children in kindergarten that embeds support for self-regulation, particularly executive functions, into literacy, mathematics, and science learning activities. Results from a cluster randomized controlled trial involving 29 schools, 79 classrooms, and 759 children indicated positive effects on executive functions, reasoning ability, the control of attention, and levels of salivary cortisol and alpha amylase. Results also demonstrated improvements in reading, vocabulary, and mathematics at the end of kindergarten that increased into the first grade. A number of effects were specific to high-poverty schools, suggesting that a focus on executive functions and associated aspects of self-regulation in early elementary education holds promise for closing the achievement gap. PMID:25389751

  19. Reliability, Recursion, and Risk.

    ERIC Educational Resources Information Center

    Henriksen, Melvin, Ed.; Wagon, Stan, Ed.

    1991-01-01

    The discrete mathematics topics of trees and computational complexity are implemented in a simple reliability program which illustrates the process advantages of the PASCAL programing language. The discussion focuses on the impact that reliability research can provide in assessment of the risks found in complex technological ventures. (Author/JJK)

  20. Monte Carlo Reliability Analysis.

    DTIC Science & Technology

    1987-10-01

    to Stochastic Processes , Prentice-Hall, Englewood Cliffs, NJ, 1975. (5) R. E. Barlow and F. Proscham, Statistical TheorX of Reliability and Life...Lewis and Z. Tu, "Monte Carlo Reliability Modeling by Inhomogeneous ,Markov Processes, Reliab. Engr. 16, 277-296 (1986). (4) E. Cinlar, Introduction

  1. Hawaii electric system reliability.

    SciTech Connect

    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 for 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.

  2. Hawaii Electric System Reliability

    SciTech Connect

    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 for 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.

  3. Chapter 9: Reliability

    SciTech Connect

    Algora, Carlos; Espinet-Gonzalez, Pilar; Vazquez, Manuel; Bosco, Nick; Miller, David; Kurtz, Sarah; Rubio, Francisca; McConnell,Robert

    2016-04-15

    This chapter describes the accumulated knowledge on CPV reliability with its fundamentals and qualification. It explains the reliability of solar cells, modules (including optics) and plants. The chapter discusses the statistical distributions, namely exponential, normal and Weibull. The reliability of solar cells includes: namely the issues in accelerated aging tests in CPV solar cells, types of failure and failures in real time operation. The chapter explores the accelerated life tests, namely qualitative life tests (mainly HALT) and quantitative accelerated life tests (QALT). It examines other well proven and experienced PV cells and/or semiconductor devices, which share similar semiconductor materials, manufacturing techniques or operating conditions, namely, III-V space solar cells and light emitting diodes (LEDs). It addresses each of the identified reliability issues and presents the current state of the art knowledge for their testing and evaluation. Finally, the chapter summarizes the CPV qualification and reliability standards.

  4. Reliability of plantar pressure platforms.

    PubMed

    Hafer, Jocelyn F; Lenhoff, Mark W; Song, Jinsup; Jordan, Joanne M; Hannan, Marian T; Hillstrom, Howard J

    2013-07-01

    Plantar pressure measurement is common practice in many research and clinical protocols. While the accuracy of some plantar pressure measuring devices and methods for ensuring consistency in data collection on plantar pressure measuring devices have been reported, the reliability of different devices when testing the same individuals is not known. This study calculated intra-mat, intra-manufacturer, and inter-manufacturer reliability of plantar pressure parameters as well as the number of plantar pressure trials needed to reach a stable estimate of the mean for an individual. Twenty-two healthy adults completed ten walking trials across each of two Novel emed-x(®) and two Tekscan MatScan(®) plantar pressure measuring devices in a single visit. Intraclass correlation (ICC) was used to describe the agreement between values measured by different devices. All intra-platform reliability correlations were greater than 0.70. All inter-emed-x(®) reliability correlations were greater than 0.70. Inter-MatScan(®) reliability correlations were greater than 0.70 in 31 and 52 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. Inter-manufacturer reliability including all four devices was greater than 0.70 for 52 and 56 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. All parameters reached a value within 90% of an unbiased estimate of the mean within five trials. Overall, reliability results are encouraging for investigators and clinicians who may have plantar pressure data sets that include data collected on different devices.

  5. SU-E-T-357: Semi-Automated Knowledge-Based Radiation Therapy (KBRT) Planning for Head-And-Neck Cancer (HNC): Can KBRT Plans Achieve Better Results Than Manual Planning?

    SciTech Connect

    Lutzky, C; Grzetic, S; Lo, J; Das, S

    2014-06-01

    Purpose: Knowledge Based Radiation Therapy Treatment (KBRT) planning can be used to semi-automatically generate IMRT plans for new patients using constraints derived from previously manually-planned, geometrically similar patients. We investigate whether KBRT plans can achieve greater dose sparing than manual plans using optimized, organspecific constraint weighting factors. Methods: KBRT planning of HNC radiotherapy cases geometrically matched each new (query) case to one of the 105 clinically approved plans in our database. The dose distribution of the planned match was morphed to fit the querys geometry. Dose-volume constraints extracted from the morphed dose distribution were used to run the IMRT optimization with no user input. In the first version, all constraints were multiplied by a weighting factor of 0.7. The weighting factors were then systematically optimized (in order of OARs with increasing separation from the target) to maximize sparing to each OAR without compromising other OARs. The optimized, second version plans were compared against the first version plans and the clinically approved plans for 45 unilateral/bilateral target cases using the dose metrics: mean, median and maximum (brainstem and cord) doses. Results: Compared to the first version, the second version significantly reduced mean/median contralateral parotid doses (>2Gy) for bilateral cases. Other changes between the two versions were not clinically meaningful. Compared to the original clinical plans, both bilateral and unilateral plans in the second version had lower average dose metrics for 5 of the 6 OARs. Compared to the original plans, the second version achieved dose sparing that was at least as good for all OARs and better for the ipsilateral parotid (bilateral) and oral cavity (bilateral/unilateral). Differences in planning target volume coverage metrics were not clinically significant. Conclusion: HNC-KBRT planning generated IMRT plans with at least equivalent dose sparing to

  6. Software reliability models for critical applications

    SciTech Connect

    Pham, H.; Pham, M.

    1991-12-01

    This report presents the results of the first phase of the ongoing EG&G Idaho, Inc. Software Reliability Research Program. The program is studying the existing software reliability models and proposes a state-of-the-art software reliability model that is relevant to the nuclear reactor control environment. This report consists of three parts: (1) summaries of the literature review of existing software reliability and fault tolerant software reliability models and their related issues, (2) proposed technique for software reliability enhancement, and (3) general discussion and future research. The development of this proposed state-of-the-art software reliability model will be performed in the second place. 407 refs., 4 figs., 2 tabs.

  7. Software reliability models for critical applications

    SciTech Connect

    Pham, H.; Pham, M.

    1991-12-01

    This report presents the results of the first phase of the ongoing EG G Idaho, Inc. Software Reliability Research Program. The program is studying the existing software reliability models and proposes a state-of-the-art software reliability model that is relevant to the nuclear reactor control environment. This report consists of three parts: (1) summaries of the literature review of existing software reliability and fault tolerant software reliability models and their related issues, (2) proposed technique for software reliability enhancement, and (3) general discussion and future research. The development of this proposed state-of-the-art software reliability model will be performed in the second place. 407 refs., 4 figs., 2 tabs.

  8. Mechanically reliable scales and coatings

    SciTech Connect

    Tortorelli, P.F.; Alexander, K.B.

    1995-07-01

    As the first stage in examining the mechanical reliability of protective surface oxides, the behavior of alumina scales formed on iron-aluminum alloys during high-temperature cyclic oxidation was characterized in terms of damage and spallation tendencies. Scales were thermally grown on specimens of three iron-aluminum composition using a series of exposures to air at 1000{degrees}C. Gravimetric data and microscopy revealed substantially better integrity and adhesion of the scales grown on an alloy containing zirconium. The use of polished (rather than just ground) specimens resulted in scales that were more suitable for subsequent characterization of mechanical reliability.

  9. Mission reliability model programmers guide

    NASA Astrophysics Data System (ADS)

    Medina, Joseph M.; Simonson, Jonathan H.; Veatch, Michael H.

    1986-12-01

    The Mission Reliability Model (MIREM) has been developed to evaluate the reliability and sustained operating capability of advanced electronic circuits during the early stages of development. MIREM is applicable to integrated systems that achieve fault tolerance through dynamic fault detection, fault isolation, and reconfiguration. The model can also be valuable in evaluating designs that employ only dedicated or hard-wired redundancy. The most unique feature of MIREM is its ability to accurately reflect the impact of reconfigurable, competing functions on system reliability. The user defines the resources necessary to support a required function, e.g., Global Positioning System (GPS), and the model will compute the probability of losing that functional capability over a certain operating time. A critical failure occurs when there is not a sufficient number of working resources to support a specified function. As an analytic model, MIREM determines a value for Mean Time Between Critical Failure, Mission Completion Success Probability, and Failure Resiliency. The MIREM Programmers Guide addresses the model's program structure, function of routines, interdependence of subprograms and common blocks, and file usage. The information needed to port the model to other computer systems is also provided.

  10. Reliability Analysis of Money Habitudes

    ERIC Educational Resources Information Center

    Delgadillo, Lucy M.; Bushman, Brittani S.

    2015-01-01

    Use of the Money Habitudes exercise has gained popularity among various financial professionals. This article reports on the reliability of this resource. A survey administered to young adults at a western state university was conducted, and each Habitude or "domain" was analyzed using Cronbach's alpha procedures. Results showed all six…

  11. The Reliability of College Grades

    ERIC Educational Resources Information Center

    Beatty, Adam S.; Walmsley, Philip T.; Sackett, Paul R.; Kuncel, Nathan R.; Koch, Amanda J.

    2015-01-01

    Little is known about the reliability of college grades relative to how prominently they are used in educational research, and the results to date tend to be based on small sample studies or are decades old. This study uses two large databases (N > 800,000) from over 200 educational institutions spanning 13 years and finds that both first-year…

  12. Assessing the Reliability of Beck Depression Inventory Scores: Reliability Generalization across Studies.

    ERIC Educational Resources Information Center

    Yin, Ping; Fan, Xitao

    2000-01-01

    Performed a meta-analysis of reliability estimates for Beck Depression Inventory (BDI) (A. Beck and others, 1961) scores across studies. Only 7.5% of studies reviewed (n=1,200) reported meaningful reliability estimates. Analysis results suggest that standard errors of measurement should be considered in addition to reliability estimates when…

  13. Developing a Comprehensive Teaching Evaluation System for Foundation Courses with Enhanced Validity and Reliability

    ERIC Educational Resources Information Center

    Xu, Yueyu

    2012-01-01

    This study aims at developing a comprehensive teaching evaluation system, a more useful educational technology, for achieving relatively reliable and valid results that can be well acknowledged by instructors, students, and by administrators. Adopting multi-method approaches, the study integrates student evaluation, expert evaluation and regular…

  14. Reliability Analysis Model

    NASA Technical Reports Server (NTRS)

    1970-01-01

    RAM program determines probability of success for one or more given objectives in any complex system. Program includes failure mode and effects, criticality and reliability analyses, and some aspects of operations, safety, flight technology, systems design engineering, and configuration analyses.

  15. Metrology automation reliability

    NASA Astrophysics Data System (ADS)

    Chain, Elizabeth E.

    1996-09-01

    At Motorola's MOS-12 facility automated measurements on 200- mm diameter wafers proceed in a hands-off 'load-and-go' mode requiring only wafer loading, measurement recipe loading, and a 'run' command for processing. Upon completion of all sample measurements, the data is uploaded to the factory's data collection software system via a SECS II interface, eliminating the requirement of manual data entry. The scope of in-line measurement automation has been extended to the entire metrology scheme from job file generation to measurement and data collection. Data analysis and comparison to part specification limits is also carried out automatically. Successful integration of automated metrology into the factory measurement system requires that automated functions, such as autofocus and pattern recognition algorithms, display a high degree of reliability. In the 24- hour factory reliability data can be collected automatically on every part measured. This reliability data is then uploaded to the factory data collection software system at the same time as the measurement data. Analysis of the metrology reliability data permits improvements to be made as needed, and provides an accurate accounting of automation reliability. This reliability data has so far been collected for the CD-SEM (critical dimension scanning electron microscope) metrology tool, and examples are presented. This analysis method can be applied to such automated in-line measurements as CD, overlay, particle and film thickness measurements.

  16. Highly reliable multisensor array (MSA) smart transducers

    NASA Astrophysics Data System (ADS)

    Perotti, José; Lucena, Angel; Mackey, Paul; Mata, Carlos; Immer, Christopher

    2006-05-01

    Many developments in the field of multisensor array (MSA) transducers have taken place in the last few years. Advancements in fabrication technology, such as Micro-Electro-Mechanical Systems (MEMS) and nanotechnology, have made implementation of MSA devices a reality. NASA Kennedy Space Center (KSC) has been developing this type of technology because of the increases in safety, reliability, and performance and the reduction in operational and maintenance costs that can be achieved with these devices. To demonstrate the MSA technology benefits, KSC quantified the relationship between the number of sensors (N) and the associated improvement in sensor life and reliability. A software algorithm was developed to monitor and assess the health of each element and the overall MSA. Furthermore, the software algorithm implemented criteria on how these elements would contribute to the MSA-calculated output to ensure required performance. The hypothesis was that a greater number of statistically independent sensor elements would provide a measurable increase in measurement reliability. A computer simulation was created to answer this question. An array of N sensors underwent random failures in the simulation and a life extension factor (LEF equals the percentage of the life of a single sensor) was calculated by the program. When LEF was plotted as a function of N, a quasiexponential behavior was detected with marginal improvement above N = 30. The hypothesis and follow-on simulation results were then corroborated experimentally. An array composed of eight independent pressure sensors was fabricated. To accelerate sensor life cycle and failure and to simulate degradation over time, the MSA was exposed to an environmental tem-perature of 125°C. Every 24 hours, the experiment's environmental temperature was returned to ambient temperature (27°C), and the outputs of all the MSA sensor elements were measured. Once per week, the MSA calibration was verified at five different

  17. Reliability: A Comparison of Absence Measures.

    DTIC Science & Technology

    1985-09-01

    1965). Other methods of estimating internal consistency, such as Kuder - Richardson formula 20, involve analysis of item variance and are more... formula . The results show the frequency indices to be very reliable , but that a carefully defined and measured index like sick leave hours lost can provide... formulas show that reliability is interpreted as a coefficient of determination (Guilford, 1954). The conceptual difference is that reliability concerns

  18. Reliability Analysis and Reliability-Based Design Optimization of Circular Composite Cylinders Under Axial Compression

    NASA Technical Reports Server (NTRS)

    Rais-Rohani, Masoud

    2001-01-01

    This report describes the preliminary results of an investigation on component reliability analysis and reliability-based design optimization of thin-walled circular composite cylinders with average diameter and average length of 15 inches. Structural reliability is based on axial buckling strength of the cylinder. Both Monte Carlo simulation and First Order Reliability Method are considered for reliability analysis with the latter incorporated into the reliability-based structural optimization problem. To improve the efficiency of reliability sensitivity analysis and design optimization solution, the buckling strength of the cylinder is estimated using a second-order response surface model. The sensitivity of the reliability index with respect to the mean and standard deviation of each random variable is calculated and compared. The reliability index is found to be extremely sensitive to the applied load and elastic modulus of the material in the fiber direction. The cylinder diameter was found to have the third highest impact on the reliability index. Also the uncertainty in the applied load, captured by examining different values for its coefficient of variation, is found to have a large influence on cylinder reliability. The optimization problem for minimum weight is solved subject to a design constraint on element reliability index. The methodology, solution procedure and optimization results are included in this report.

  19. Back to the Basics: In Defense of Achievement (and Achievement Tests) in College Admissions

    ERIC Educational Resources Information Center

    Geiser, Saul

    2009-01-01

    In this article, the author describes the growth and acceptance of achievement tests, such as the Scholastic Aptitude Test (SAT), over the past century, advocating that many SAT claims of equity, uniformity, technical reliability, and prediction, over traditional measures of academic achievement have been found to be illusory. Summarizing a series…

  20. Data reliability from an instrumented vertical jump platform.

    PubMed

    Caruso, John F; Daily, Jeremy S; McLagan, Jessica R; Shepherd, Catherine M; Olson, Nathan M; Marshall, Mallory R; Taylor, Skyler T

    2010-10-01

    A Vertec jump measurement and training system measures vertical jump heights but not additional variables that would reveal how the performance was achieved. Technology advances to equipment now include additional variables that elucidate how jump performance is achieved. However, acceptance of new jump-related equipment is predicated on the reliability of the vertical heights it measures in relation to those assessed by the Vertec. Thus, our study compared vertical jump height reliability data from a newly created instrumented platform to those concurrently derived from the Vertec. Methods required subjects (n = 105) to perform 2 jump trials separated by at least 2 days of rest. Trials began with a warm-up, followed by 3 to 5 maximal-effort jumps. The Vertec was placed directly over the platform so, as jumps occurred, subjects took off and landed on the instrumented device. At the jump apex subjects contacted the highest Vertec slapstick possible to assess maximum height attained. Four height measurements were derived from each jump: 3 platform-based calculations (from subject's take-off, hang time, and landing) and 1 Vertec. The platform-based calculations were compared to Vertec data to assess the reliability of the instrumented device. Intraclass correlation coefficient (0.90), coefficient of variation (17.3%), standard error of measurement (0.9 cm), and smallest real difference (3.7 cm) results showed heights calculated from platform take-offs were most reliable to Vertec values. It was concluded take-off from the platform yielded jump heights that are a viable alternative to those derived from the Vertec. Practical applications suggest coaches may use the platform to derive reliable vertical jump data in addition to other variables to better understand the performance of their athletes.

  1. Damage Tolerance and Reliability of Turbine Engine Components

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1999-01-01

    This report describes a formal method to quantify structural damage tolerance and reliability in the presence of a multitude of uncertainties in turbine engine components. The method is based at the material behavior level where primitive variables with their respective scatter ranges are used to describe behavior. Computational simulation is then used to propagate the uncertainties to the structural scale where damage tolerance and reliability are usually specified. Several sample cases are described to illustrate the effectiveness, versatility, and maturity of the method. Typical results from this method demonstrate that it is mature and that it can be used to probabilistically evaluate turbine engine structural components. It may be inferred from the results that the method is suitable for probabilistically predicting the remaining life in aging or deteriorating structures, for making strategic projections and plans, and for achieving better, cheaper, faster products that give competitive advantages in world markets.

  2. Estimating the Reliability of a Crewed Spacecraft

    NASA Astrophysics Data System (ADS)

    Lutomski, M. G.; Garza, J.

    2012-01-01

    Now that the Space Shuttle Program has been retired, the Russian Soyuz Launcher and Soyuz Spacecraft are the only means for crew transportation to and from the International Space Station (ISS). Are the astronauts and cosmonauts safer on the Soyuz than the Space Shuttle system? How do you estimate the reliability of such a crewed spacecraft? The recent loss of the 44 Progress resupply flight to the ISS has put these questions front and center. The Soyuz launcher has been in operation for over 40 years. There have been only two Loss of Crew (LOC) incidents and two Loss of Mission (LOM) incidents involving crew missions. Given that the most recent crewed Soyuz launcher incident took place in 1983, how do we determine current reliability of such a system? How do all of the failures of unmanned Soyuz family launchers such as the 44P impact the reliability of the currently operational crewed launcher? Does the Soyuz exhibit characteristics that demonstrate reliability growth and how would that be reflected in future estimates of success? In addition NASA has begun development of the Orion or Multi-Purpose Crewed Vehicle as well as started an initiative to purchase Commercial Crew services from private firms. The reliability targets are currently several times higher than the last Shuttle reliability estimate. Can these targets be compared to the reliability of the Soyuz arguably the highest reliable crewed spacecraft and launcher in the world to determine whether they are realistic and achievable? To help answer these questions this paper will explore how to estimate the reliability of the Soyuz launcher/spacecraft system over its mission to give a benchmark for other human spaceflight vehicles and their missions. Specifically this paper will look at estimating the Loss of Mission (LOM) and Loss of Crew (LOC) probability for an ISS crewed Soyuz launcher/spacecraft mission using historical data, reliability growth, and Probabilistic Risk Assessment (PRA) techniques.

  3. Statistical modelling of software reliability

    NASA Technical Reports Server (NTRS)

    Miller, Douglas R.

    1991-01-01

    During the six-month period from 1 April 1991 to 30 September 1991 the following research papers in statistical modeling of software reliability appeared: (1) A Nonparametric Software Reliability Growth Model; (2) On the Use and the Performance of Software Reliability Growth Models; (3) Research and Development Issues in Software Reliability Engineering; (4) Special Issues on Software; and (5) Software Reliability and Safety.

  4. Photovoltaic module reliability workshop

    SciTech Connect

    Mrig, L.

    1990-01-01

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986--1990. The reliability Photo Voltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warranties available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the US, PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  5. Photovoltaic module reliability workshop

    NASA Astrophysics Data System (ADS)

    Mrig, L.

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986 to 1990. The reliability photovoltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warrantees available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the U.S., PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  6. Proposed reliability cost model

    NASA Technical Reports Server (NTRS)

    Delionback, L. M.

    1973-01-01

    The research investigations which were involved in the study include: cost analysis/allocation, reliability and product assurance, forecasting methodology, systems analysis, and model-building. This is a classic example of an interdisciplinary problem, since the model-building requirements include the need for understanding and communication between technical disciplines on one hand, and the financial/accounting skill categories on the other. The systems approach is utilized within this context to establish a clearer and more objective relationship between reliability assurance and the subcategories (or subelements) that provide, or reenforce, the reliability assurance for a system. Subcategories are further subdivided as illustrated by a tree diagram. The reliability assurance elements can be seen to be potential alternative strategies, or approaches, depending on the specific goals/objectives of the trade studies. The scope was limited to the establishment of a proposed reliability cost-model format. The model format/approach is dependent upon the use of a series of subsystem-oriented CER's and sometimes possible CTR's, in devising a suitable cost-effective policy.

  7. Photovoltaic performance and reliability workshop

    SciTech Connect

    Kroposki, B

    1996-10-01

    This proceedings is the compilation of papers presented at the ninth PV Performance and Reliability Workshop held at the Sheraton Denver West Hotel on September 4--6, 1996. This years workshop included presentations from 25 speakers and had over 100 attendees. All of the presentations that were given are included in this proceedings. Topics of the papers included: defining service lifetime and developing models for PV module lifetime; examining and determining failure and degradation mechanisms in PV modules; combining IEEE/IEC/UL testing procedures; AC module performance and reliability testing; inverter reliability/qualification testing; standardization of utility interconnect requirements for PV systems; need activities to separate variables by testing individual components of PV systems (e.g. cells, modules, batteries, inverters,charge controllers) for individual reliability and then test them in actual system configurations; more results reported from field experience on modules, inverters, batteries, and charge controllers from field deployed PV systems; and system certification and standardized testing for stand-alone and grid-tied systems.

  8. Reliability Centered Maintenance - Methodologies

    NASA Technical Reports Server (NTRS)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  9. Limitations of Reliability for Long-Endurance Human Spaceflight

    NASA Technical Reports Server (NTRS)

    Owens, Andrew C.; de Weck, Olivier L.

    2016-01-01

    Long-endurance human spaceflight - such as missions to Mars or its moons - will present a never-before-seen maintenance logistics challenge. Crews will be in space for longer and be farther way from Earth than ever before. Resupply and abort options will be heavily constrained, and will have timescales much longer than current and past experience. Spare parts and/or redundant systems will have to be included to reduce risk. However, the high cost of transportation means that this risk reduction must be achieved while also minimizing mass. The concept of increasing system and component reliability is commonly discussed as a means to reduce risk and mass by reducing the probability that components will fail during a mission. While increased reliability can reduce maintenance logistics mass requirements, the rate of mass reduction decreases over time. In addition, reliability growth requires increased test time and cost. This paper assesses trends in test time requirements, cost, and maintenance logistics mass savings as a function of increase in Mean Time Between Failures (MTBF) for some or all of the components in a system. In general, reliability growth results in superlinear growth in test time requirements, exponential growth in cost, and sublinear benefits (in terms of logistics mass saved). These trends indicate that it is unlikely that reliability growth alone will be a cost-effective approach to maintenance logistics mass reduction and risk mitigation for long-endurance missions. This paper discusses these trends as well as other options to reduce logistics mass such as direct reduction of part mass, commonality, or In-Space Manufacturing (ISM). Overall, it is likely that some combination of all available options - including reliability growth - will be required to reduce mass and mitigate risk for future deep space missions.

  10. Leader as achiever.

    PubMed

    Dienemann, Jacqueline

    2002-01-01

    This article examines one outcome of leadership: productive achievement. Without achievement one is judged to not truly be a leader. Thus, the ideal leader must be a visionary, a critical thinker, an expert, a communicator, a mentor, and an achiever of organizational goals. This article explores the organizational context that supports achievement, measures of quality nursing care, fiscal accountability, leadership development, rewards and punishments, and the educational content and teaching strategies to prepare graduates to be achievers.

  11. Gearbox Reliability Collaborative Update (Presentation)

    SciTech Connect

    Sheng, S.; Keller, J.; Glinsky, C.

    2013-10-01

    This presentation was given at the Sandia Reliability Workshop in August 2013 and provides information on current statistics, a status update, next steps, and other reliability research and development activities related to the Gearbox Reliability Collaborative.

  12. Reliability Engineering Handbook

    DTIC Science & Technology

    1964-06-01

    INTEVAL 00 0 542 917 1953 OPERATING TIME IN HOURS Figure 6-4. TWT Reliability Function, Showing the 90% Confidence Interval 6-7 6-2-4 to 6-2-5 NAVWEPS...the lower one-sided 90% greater than 977 hours, or 90% confidence confidence limit on 0 is (.704)(530) = 373 that 0 lies between these two bounds . R...6-4 6-2-2 Measurement of Reliability (Application of Confidence Limits).. 6-4 6-2-3 Procedural Steps

  13. Reliability and Failure in NASA Missions: Blunders, Normal Accidents, High Reliability, Bad Luck

    NASA Technical Reports Server (NTRS)

    Jones, Harry W.

    2015-01-01

    NASA emphasizes crew safety and system reliability but several unfortunate failures have occurred. The Apollo 1 fire was mistakenly unanticipated. After that tragedy, the Apollo program gave much more attention to safety. The Challenger accident revealed that NASA had neglected safety and that management underestimated the high risk of shuttle. Probabilistic Risk Assessment was adopted to provide more accurate failure probabilities for shuttle and other missions. NASA's "faster, better, cheaper" initiative and government procurement reform led to deliberately dismantling traditional reliability engineering. The Columbia tragedy and Mars mission failures followed. Failures can be attributed to blunders, normal accidents, or bad luck. Achieving high reliability is difficult but possible.

  14. Design and Implementation of Secure and Reliable Communication using Optical Wireless Communication

    NASA Astrophysics Data System (ADS)

    Saadi, Muhammad; Bajpai, Ambar; Zhao, Yan; Sangwongngam, Paramin; Wuttisittikulkij, Lunchakorn

    2014-11-01

    Wireless networking intensify the tractability in the home and office environment to connect the internet without wires but at the cost of risks associated with stealing the data or threat of loading malicious code with the intention of harming the network. In this paper, we proposed a novel method of establishing a secure and reliable communication link using optical wireless communication (OWC). For security, spatial diversity based transmission using two optical transmitters is used and the reliability in the link is achieved by a newly proposed method for the construction of structured parity check matrix for binary Low Density Parity Check (LDPC) codes. Experimental results show that a successful secure and reliable link between the transmitter and the receiver can be achieved by using the proposed novel technique.

  15. Coefficient Alpha and Reliability of Scale Scores

    ERIC Educational Resources Information Center

    Almehrizi, Rashid S.

    2013-01-01

    The majority of large-scale assessments develop various score scales that are either linear or nonlinear transformations of raw scores for better interpretations and uses of assessment results. The current formula for coefficient alpha (a; the commonly used reliability coefficient) only provides internal consistency reliability estimates of raw…

  16. Power and Reliability for Correlation and ANOVA.

    ERIC Educational Resources Information Center

    Brooks, Gordon P.; Kanyongo, Gibbs Y.; Kyei-Blankson, Lydia; Gocmen, Gulsah

    Unfortunately, researchers do not usually have measurement instruments that provide perfectly reliable scores. Therefore, the researcher may want to account for the level of unreliability by appropriately increasing the sample size. For example, the results of a pilot study may indicate that a particular instrument is not as reliable with a given…

  17. Reliable 100 kbps low-voltage ac powerline communications

    NASA Astrophysics Data System (ADS)

    Ladas, Chris; Propp, Michael

    1995-12-01

    Achieving reliable, 100 kbps powerline communications on the low voltage, AC powerlines has been realized by combining new techniques in spread spectrum technology with a robust, powerline specific protocol. This approach enables reliable, high speed data networking on the electrically hostile, low voltage powerline. Applications for the new technology include utility DA/DSM (distribution automation/demand side management), intraoffice LANs, powerline based telephony, and industrial data networking applications. This technological advancement was made possible through statistical modeling of the low voltage powerline, and developing unique spread spectrum and protocol techniques specific to the resulting powerline environment. The technology has been implemented as a highly integrated, CMOS chip set, allowing straightforward integration into OEM systems and products.

  18. High reliability linear drive device for artificial hearts

    NASA Astrophysics Data System (ADS)

    Ji, Jinghua; Zhao, Wenxiang; Liu, Guohai; Shen, Yue; Wang, Fangqun

    2012-04-01

    In this paper, a new high reliability linear drive device, termed as stator-permanent-magnet tubular oscillating actuator (SPM-TOA), is proposed for artificial hearts (AHs). The key is to incorporate the concept of two independent phases into this linear AH device, hence achieving high reliability operation. The fault-tolerant teeth are employed to provide the desired decoupling phases in magnetic circuit. Also, as the magnets and the coils are located in the stator, the proposed SPM-TOA takes the definite advantages of robust mover and direct-drive capability. By using the time-stepping finite element method, the electromagnetic characteristics of the proposed SPM-TOA are analyzed, including magnetic field distributions, flux linkages, back- electromotive forces (back-EMFs) self- and mutual inductances, as well as cogging and thrust forces. The results confirm that the proposed SPM-TOA meets the dimension, weight, and force requirements of the AH drive device.

  19. Early Intervention and Student Achievement

    ERIC Educational Resources Information Center

    Hormes, Mridula T.

    2009-01-01

    The United States Department of Education has been rigorous in holding all states accountable with regard to student achievement. The No Child Left Behind Act of 2001 clearly laid out federal mandates for all schools to follow. K-12 leaders of public schools are very aware of the fact that results in terms of student achievement need to improve…

  20. Parental Involvement and Academic Achievement

    ERIC Educational Resources Information Center

    Goodwin, Sarah Christine

    2015-01-01

    This research study examined the correlation between student achievement and parent's perceptions of their involvement in their child's schooling. Parent participants completed the Parent Involvement Project Parent Questionnaire. Results slightly indicated parents of students with higher level of achievement perceived less demand or invitations…

  1. Reliability Prediction for Aerospace Electronics

    DTIC Science & Technology

    2015-04-20

    methodology can be extended to include radiation effects, frequency, and even packaging and solder joint effects to give a complete system...assume that there is no failure analysis (FA) of the devices after the HTOL test, or that the manufacturer will not report FA results to the...effects, frequency and even packaging and solder joint effects to give a complete system reliability evaluation framework. This matrix gives a very

  2. Assuring Software Reliability

    DTIC Science & Technology

    2014-08-01

    resources.sei.cmu.edu/asset_files/WhitePaper/2009_019_001_29066.pdf [Boydston 2009] Boydston, A. & Lewis , W. Qualification and Reliability of...Woody, Carol . Survivability Analysis Framework (CMU/SEI-2010-TN-013). Software Engineering Institute, Carnegie Mellon University, 2010. http

  3. Parametric Mass Reliability Study

    NASA Technical Reports Server (NTRS)

    Holt, James P.

    2014-01-01

    The International Space Station (ISS) systems are designed based upon having redundant systems with replaceable orbital replacement units (ORUs). These ORUs are designed to be swapped out fairly quickly, but some are very large, and some are made up of many components. When an ORU fails, it is replaced on orbit with a spare; the failed unit is sometimes returned to Earth to be serviced and re-launched. Such a system is not feasible for a 500+ day long-duration mission beyond low Earth orbit. The components that make up these ORUs have mixed reliabilities. Components that make up the most mass-such as computer housings, pump casings, and the silicon board of PCBs-typically are the most reliable. Meanwhile components that tend to fail the earliest-such as seals or gaskets-typically have a small mass. To better understand the problem, my project is to create a parametric model that relates both the mass of ORUs to reliability, as well as the mass of ORU subcomponents to reliability.

  4. Designing reliability into accelerators

    SciTech Connect

    Hutton, A.

    1992-08-01

    For the next generation of high performance, high average luminosity colliders, the ``factories,`` reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis.

  5. Designing reliability into accelerators

    SciTech Connect

    Hutton, A.

    1992-08-01

    For the next generation of high performance, high average luminosity colliders, the factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis.

  6. Reliable solar cookers

    SciTech Connect

    Magney, G.K.

    1992-12-31

    The author describes the activities of SERVE, a Christian relief and development agency, to introduce solar ovens to the Afghan refugees in Pakistan. It has provided 5,000 solar cookers since 1984. The experience has demonstrated the potential of the technology and the need for a durable and reliable product. Common complaints about the cookers are discussed and the ideal cooker is described.

  7. Reliability Design Handbook

    DTIC Science & Technology

    1976-03-01

    prediction, failure modes and effects analysis ( FMEA ) and reliability growth techniques represent those prediction and design evaluation methods that...Assessment Production Operation Ö Maintenance MIL-HDBK- 217 Bayesian Techniques Probabilistic Design FMEA I R Growth " I...devices suffer thermal aging; oxidation and other chemical reactions are enhanced; viscosity reduction and evaporation of lubricants are problems

  8. Reliable vision-guided grasping

    NASA Technical Reports Server (NTRS)

    Nicewarner, Keith E.; Kelley, Robert B.

    1992-01-01

    Automated assembly of truss structures in space requires vision-guided servoing for grasping a strut when its position and orientation are uncertain. This paper presents a methodology for efficient and robust vision-guided robot grasping alignment. The vision-guided grasping problem is related to vision-guided 'docking' problems. It differs from other hand-in-eye visual servoing problems, such as tracking, in that the distance from the target is a relevant servo parameter. The methodology described in this paper is hierarchy of levels in which the vision/robot interface is decreasingly 'intelligent,' and increasingly fast. Speed is achieved primarily by information reduction. This reduction exploits the use of region-of-interest windows in the image plane and feature motion prediction. These reductions invariably require stringent assumptions about the image. Therefore, at a higher level, these assumptions are verified using slower, more reliable methods. This hierarchy provides for robust error recovery in that when a lower-level routine fails, the next-higher routine will be called and so on. A working system is described which visually aligns a robot to grasp a cylindrical strut. The system uses a single camera mounted on the end effector of a robot and requires only crude calibration parameters. The grasping procedure is fast and reliable, with a multi-level error recovery system.

  9. Reliability Generalization (RG) Analysis: The Test Is Not Reliable

    ERIC Educational Resources Information Center

    Warne, Russell

    2008-01-01

    Literature shows that most researchers are unaware of some of the characteristics of reliability. This paper clarifies some misconceptions by describing the procedures, benefits, and limitations of reliability generalization while using it to illustrate the nature of score reliability. Reliability generalization (RG) is a meta-analytic method…

  10. 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.

  11. Teacher Involvement To Evaluate Science Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Teacher-developed tests can be more valid and reliable than standardized tests or state-mandated tests in evaluating student achievement in science. Many teachers, however, are not acquainted with the standards to use in test writing. The National Research Council has released "Classroom Assessment and the National Education Standards," a…

  12. Three brief assessments of math achievement.

    PubMed

    Steiner, Eric T; Ashcraft, Mark H

    2012-12-01

    Because of wide disparities in college students' math knowledge-that is, their math achievement-studies of cognitive processing in math tasks also need to assess their individual level of math achievement. For many research settings, however, using existing math achievement tests is either too costly or too time consuming. To solve this dilemma, we present three brief tests of math achievement here, two drawn from the Wide Range Achievement Test and one composed of noncopyrighted items. All three correlated substantially with the full achievement test and with math anxiety, our original focus, and all show acceptable to excellent reliability. When lengthy testing is not feasible, one of these brief tests can be substituted.

  13. Test effectiveness study report: An analytical study of system test effectiveness and reliability growth of three commercial spacecraft programs

    NASA Technical Reports Server (NTRS)

    Feldstein, J. F.

    1977-01-01

    Failure data from 16 commercial spacecraft were analyzed to evaluate failure trends, reliability growth, and effectiveness of tests. It was shown that the test programs were highly effective in ensuring a high level of in-orbit reliability. There was only a single catastrophic problem in 44 years of in-orbit operation on 12 spacecraft. The results also indicate that in-orbit failure rates are highly correlated with unit and systems test failure rates. The data suggest that test effectiveness estimates can be used to guide the content of a test program to ensure that in-orbit reliability goals are achieved.

  14. 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.

  15. Comparing Science Achievement Constructs: Targeted and Achieved

    ERIC Educational Resources Information Center

    Ferrara, Steve; Duncan, Teresa

    2011-01-01

    This article illustrates how test specifications based solely on academic content standards, without attention to other cognitive skills and item response demands, can fall short of their targeted constructs. First, the authors inductively describe the science achievement construct represented by a statewide sixth-grade science proficiency test.…

  16. Three approaches to reliability analysis

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L.

    1989-01-01

    It is noted that current reliability analysis tools differ not only in their solution techniques, but also in their approach to model abstraction. The analyst must be satisfied with the constraints that are intrinsic to any combination of solution technique and model abstraction. To get a better idea of the nature of these constraints, three reliability analysis tools (HARP, ASSIST/SURE, and CAME) were used to model portions of the Integrated Airframe/Propulsion Control System architecture. When presented with the example problem, all three tools failed to produce correct results. In all cases, either the tool or the model had to be modified. It is suggested that most of the difficulty is rooted in the large model size and long computational times which are characteristic of Markov model solutions.

  17. Which Achievement Gap?

    ERIC Educational Resources Information Center

    Anderson, Sharon; Medrich, Elliott; Fowler, Donna

    2007-01-01

    From the halls of Congress to the local elementary school, conversations on education reform have tossed around the term "achievement gap" as though people all know precisely what that means. As it's commonly used, "achievement gap" refers to the differences in scores on state or national achievement tests between various…

  18. Space Shuttle Propulsion System Reliability

    NASA Technical Reports Server (NTRS)

    Welzyn, Ken; VanHooser, Katherine; Moore, Dennis; Wood, David

    2011-01-01

    This session includes the following sessions: (1) External Tank (ET) System Reliability and Lessons, (2) Space Shuttle Main Engine (SSME), Reliability Validated by a Million Seconds of Testing, (3) Reusable Solid Rocket Motor (RSRM) Reliability via Process Control, and (4) Solid Rocket Booster (SRB) Reliability via Acceptance and Testing.

  19. Construction of Valid and Reliable Test for Assessment of Students

    ERIC Educational Resources Information Center

    Osadebe, P. U.

    2015-01-01

    The study was carried out to construct a valid and reliable test in Economics for secondary school students. Two research questions were drawn to guide the establishment of validity and reliability for the Economics Achievement Test (EAT). It is a multiple choice objective test of five options with 100 items. A sample of 1000 students was randomly…

  20. System Reliability Assessment for a Rock Tunnel with Multiple Failure Modes

    NASA Astrophysics Data System (ADS)

    Lü, Qing; Chan, Chin Loong; Low, Bak Kong

    2013-07-01

    This paper presents a practical procedure for assessing the system reliability of a rock tunnel. Three failure modes, namely, inadequate support capacity, excessive tunnel convergence, and insufficient rockbolt length, are considered and investigated using a deterministic model of ground-support interaction analysis based on the convergence-confinement method (CCM). The failure probability of each failure mode is evaluated from the first-order reliability method (FORM) and the response surface method (RSM) via an iterative procedure. The system failure probability bounds are estimated using the bimodal bounds approach suggested by Ditlevsen (1979), based on the reliability index and design point inferred from the FORM. The proposed approach is illustrated with an example of a circular rock tunnel. The computed system failure probability bounds compare favorably with those generated from Monte Carlo simulations. The results show that the relative importance of different failure modes to the system reliability of the tunnel mainly depends on the timing of support installation relative to the advancing tunnel face. It is also shown that reliability indices based on the second-order reliability method (SORM) can be used to achieve more accurate bounds on the system failure probability for nonlinear limit state surfaces. The system reliability-based design for shotcrete thickness is also demonstrated.

  1. Reliability improvements on Thales RM2 rotary Stirling coolers: analysis and methodology

    NASA Astrophysics Data System (ADS)

    Cauquil, J. M.; Seguineau, C.; Martin, J.-Y.; Benschop, T.

    2016-05-01

    The cooled IR detectors are used in a wide range of applications. Most of the time, the cryocoolers are one of the components dimensioning the lifetime of the system. The cooler reliability is thus one of its most important parameters. This parameter has to increase to answer market needs. To do this, the data for identifying the weakest element determining cooler reliability has to be collected. Yet, data collection based on field are hardly usable due to lack of informations. A method for identifying the improvement in reliability has then to be set up which can be used even without field return. This paper will describe the method followed by Thales Cryogénie SAS to reach such a result. First, a database was built from extensive expertizes of RM2 failures occurring in accelerate ageing. Failure modes have then been identified and corrective actions achieved. Besides this, a hierarchical organization of the functions of the cooler has been done with regard to the potential increase of its efficiency. Specific changes have been introduced on the functions most likely to impact efficiency. The link between efficiency and reliability will be described in this paper. The work on the two axes - weak spots for cooler reliability and efficiency - permitted us to increase in a drastic way the MTTF of the RM2 cooler. Huge improvements in RM2 reliability are actually proven by both field return and reliability monitoring. These figures will be discussed in the paper.

  2. Aktuelle Regelungen zur Leistungsbeurteilung und zu Zeugnissen an Deutschen Sekundarschulen. Eine Vergleichende Studie aller Bundeslander--Darstellung und Diskussion Wesentlicher Ergebnisse (Recent Regulations for the Assessment of Achievement and for Grading at German Secondary Schools. A Comparative Study among all Federal Laender--Presentation and Discussions of Important Results.

    ERIC Educational Resources Information Center

    Bohl, Thorsten

    2003-01-01

    Discusses a comparative study of regulations for assessment of achievement and grading in German secondary schools. Results reveal schools provide alternatives to traditional grading and take into account interdisciplinary or special learning achievements and social behavior. Summarizes major results. Discusses problems in the basic conception and…

  3. Human Reliability Program Workshop

    SciTech Connect

    Landers, John; Rogers, Erin; Gerke, Gretchen

    2014-05-18

    A Human Reliability Program (HRP) is designed to protect national security as well as worker and public safety by continuously evaluating the reliability of those who have access to sensitive materials, facilities, and programs. Some elements of a site HRP include systematic (1) supervisory reviews, (2) medical and psychological assessments, (3) management evaluations, (4) personnel security reviews, and (4) training of HRP staff and critical positions. Over the years of implementing an HRP, the Department of Energy (DOE) has faced various challenges and overcome obstacles. During this 4-day activity, participants will examine programs that mitigate threats to nuclear security and the insider threat to include HRP, Nuclear Security Culture (NSC) Enhancement, and Employee Assistance Programs. The focus will be to develop an understanding of the need for a systematic HRP and to discuss challenges and best practices associated with mitigating the insider threat.

  4. Reliable broadcast protocols

    NASA Technical Reports Server (NTRS)

    Joseph, T. A.; Birman, Kenneth P.

    1989-01-01

    A number of broadcast protocols that are reliable subject to a variety of ordering and delivery guarantees are considered. Developing applications that are distributed over a number of sites and/or must tolerate the failures of some of them becomes a considerably simpler task when such protocols are available for communication. Without such protocols the kinds of distributed applications that can reasonably be built will have a very limited scope. As the trend towards distribution and decentralization continues, it will not be surprising if reliable broadcast protocols have the same role in distributed operating systems of the future that message passing mechanisms have in the operating systems of today. On the other hand, the problems of engineering such a system remain large. For example, deciding which protocol is the most appropriate to use in a certain situation or how to balance the latency-communication-storage costs is not an easy question.

  5. Compact, Reliable EEPROM Controller

    NASA Technical Reports Server (NTRS)

    Katz, Richard; Kleyner, Igor

    2010-01-01

    A compact, reliable controller for an electrically erasable, programmable read-only memory (EEPROM) has been developed specifically for a space-flight application. The design may be adaptable to other applications in which there are requirements for reliability in general and, in particular, for prevention of inadvertent writing of data in EEPROM cells. Inadvertent writes pose risks of loss of reliability in the original space-flight application and could pose such risks in other applications. Prior EEPROM controllers are large and complex and do not provide all reasonable protections (in many cases, few or no protections) against inadvertent writes. In contrast, the present controller provides several layers of protection against inadvertent writes. The controller also incorporates a write-time monitor, enabling determination of trends in the performance of an EEPROM through all phases of testing. The controller has been designed as an integral subsystem of a system that includes not only the controller and the controlled EEPROM aboard a spacecraft but also computers in a ground control station, relatively simple onboard support circuitry, and an onboard communication subsystem that utilizes the MIL-STD-1553B protocol. (MIL-STD-1553B is a military standard that encompasses a method of communication and electrical-interface requirements for digital electronic subsystems connected to a data bus. MIL-STD- 1553B is commonly used in defense and space applications.) The intent was to both maximize reliability while minimizing the size and complexity of onboard circuitry. In operation, control of the EEPROM is effected via the ground computers, the MIL-STD-1553B communication subsystem, and the onboard support circuitry, all of which, in combination, provide the multiple layers of protection against inadvertent writes. There is no controller software, unlike in many prior EEPROM controllers; software can be a major contributor to unreliability, particularly in fault

  6. Designing reliability into accelerators

    NASA Astrophysics Data System (ADS)

    Hutton, A.

    1992-07-01

    Future accelerators will have to provide a high degree of reliability. Quality must be designed in right from the beginning and must remain a central theme throughout the project. The problem is similar to the problems facing US industry today, and examples of the successful application of quality engineering will be given. Different aspects of an accelerator project will be addressed: Concept, Design, Motivation, Management Techniques, and Fault Diagnosis. The importance of creating and maintaining a coherent team will be stressed.

  7. Reliability and testing

    NASA Technical Reports Server (NTRS)

    Auer, Werner

    1996-01-01

    Reliability and its interdependence with testing are important topics for development and manufacturing of successful products. This generally accepted fact is not only a technical statement, but must be also seen in the light of 'Human Factors.' While the background for this paper is the experience gained with electromechanical/electronic space products, including control and system considerations, it is believed that the content could be also of interest for other fields.

  8. Laser System Reliability

    DTIC Science & Technology

    1977-03-01

    NEALE CAPT. RANDALL D. GODFREY CAPT. JOHN E. ACTON HR. DAVE B. LEMMING (ASD) :,^ 19 . ••^w**** SECTION III RELIABILITY PREDICTION...Dete Exchange Program) failure rate date bank. In addition, some data have been obtained from Hughes. Rocketdyne , Garrett, and the AFWL’s APT Failure...Central Ave, Suite 306, Albuq, NM 87108 R/M Systems, Inc (Dr. K. Blemel), 10801 Lomas 81vd NE, Albuquerque, NM 87112 Rocketdyne 01 v, Rockwell

  9. Spacecraft transmitter reliability

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A workshop on spacecraft transmitter reliability was held at the NASA Lewis Research Center on September 25 and 26, 1979, to discuss present knowledge and to plan future research areas. Since formal papers were not submitted, this synopsis was derived from audio tapes of the workshop. The following subjects were covered: users' experience with space transmitters; cathodes; power supplies and interfaces; and specifications and quality assurance. A panel discussion ended the workshop.

  10. RICOR's new development of a highly reliable integral rotary cooler: engineering and reliability aspects

    NASA Astrophysics Data System (ADS)

    Filis, Avishai; Pundak, Nachman; Barak, Moshe; Porat, Ze'ev; Jaeger, Mordechai

    2011-06-01

    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 decreased integrated system Life Cycle (ILS) cost. In order to meet this need RICOR has developed a new rotary Stirling cryocooler, model K508N, intended to double the K508's operating MTTF achieving 20,000 operating MTTF hours. The K508N employs RICOR's latest mechanical design technologies such as optimized bearings and greases, bearings preloading, advanced seals, laser welded cold finger and robust design structure with increased natural frequency compared to the K508 model. The cooler enhanced MTTF was demonstrated by a Validation and Verification (V&V) plan comprising analytical means and a comparative accelerated life test between the standard K508 and the K508N models. Particularly, point estimate and confidence interval for the MTTF improvement factor where calculated periodically during and after the test. The (V&V) effort revealed that the K508N meets its MTTF design goal. The paper will focus on the technical and engineering aspects of the new design. In addition it will discuss the market needs and expectations, investigate the reliability data of the present reference K508 model; and report the accelerate life test data and the statistical analysis methodology as well as its underlying assumptions and results.

  11. Software reliability studies

    NASA Technical Reports Server (NTRS)

    Hoppa, Mary Ann; Wilson, Larry W.

    1994-01-01

    There are many software reliability models which try to predict future performance of software based on data generated by the debugging process. Our research has shown that by improving the quality of the data one can greatly improve the predictions. We are working on methodologies which control some of the randomness inherent in the standard data generation processes in order to improve the accuracy of predictions. Our contribution is twofold in that we describe an experimental methodology using a data structure called the debugging graph and apply this methodology to assess the robustness of existing models. The debugging graph is used to analyze the effects of various fault recovery orders on the predictive accuracy of several well-known software reliability algorithms. We found that, along a particular debugging path in the graph, the predictive performance of different models can vary greatly. Similarly, just because a model 'fits' a given path's data well does not guarantee that the model would perform well on a different path. Further we observed bug interactions and noted their potential effects on the predictive process. We saw that not only do different faults fail at different rates, but that those rates can be affected by the particular debugging stage at which the rates are evaluated. Based on our experiment, we conjecture that the accuracy of a reliability prediction is affected by the fault recovery order as well as by fault interaction.

  12. General Aviation Aircraft Reliability Study

    NASA Technical Reports Server (NTRS)

    Pettit, Duane; Turnbull, Andrew; Roelant, Henk A. (Technical Monitor)

    2001-01-01

    This reliability study was performed in order to provide the aviation community with an estimate of Complex General Aviation (GA) Aircraft System reliability. To successfully improve the safety and reliability for the next generation of GA aircraft, a study of current GA aircraft attributes was prudent. This was accomplished by benchmarking the reliability of operational Complex GA Aircraft Systems. Specifically, Complex GA Aircraft System reliability was estimated using data obtained from the logbooks of a random sample of the Complex GA Aircraft population.

  13. Photovoltaic-Reliability R&D Toward a Solar-Powered World (Presentation)

    SciTech Connect

    Kurtz, S.; Granata, J.

    2009-08-01

    Presentation about the importance of continued progress toward low-cost, high-reliability, and high-performance PV systems. High reliability is an essential element in achieving low-cost solar electricity.

  14. Software reliability experiments data analysis and investigation

    NASA Technical Reports Server (NTRS)

    Walker, J. Leslie; Caglayan, Alper K.

    1991-01-01

    The objectives are to investigate the fundamental reasons which cause independently developed software programs to fail dependently, and to examine fault tolerant software structures which maximize reliability gain in the presence of such dependent failure behavior. The authors used 20 redundant programs from a software reliability experiment to analyze the software errors causing coincident failures, to compare the reliability of N-version and recovery block structures composed of these programs, and to examine the impact of diversity on software reliability using subpopulations of these programs. The results indicate that both conceptually related and unrelated errors can cause coincident failures and that recovery block structures offer more reliability gain than N-version structures if acceptance checks that fail independently from the software components are available. The authors present a theory of general program checkers that have potential application for acceptance tests.

  15. Uncertainties in obtaining high reliability from stress-strength models

    NASA Technical Reports Server (NTRS)

    Neal, Donald M.; Matthews, William T.; Vangel, Mark G.

    1992-01-01

    There has been a recent interest in determining high statistical reliability in risk assessment of aircraft components. The potential consequences are identified of incorrectly assuming a particular statistical distribution for stress or strength data used in obtaining the high reliability values. The computation of the reliability is defined as the probability of the strength being greater than the stress over the range of stress values. This method is often referred to as the stress-strength model. A sensitivity analysis was performed involving a comparison of reliability results in order to evaluate the effects of assuming specific statistical distributions. Both known population distributions, and those that differed slightly from the known, were considered. Results showed substantial differences in reliability estimates even for almost nondetectable differences in the assumed distributions. These differences represent a potential problem in using the stress-strength model for high reliability computations, since in practice it is impossible to ever know the exact (population) distribution. An alternative reliability computation procedure is examined involving determination of a lower bound on the reliability values using extreme value distributions. This procedure reduces the possibility of obtaining nonconservative reliability estimates. Results indicated the method can provide conservative bounds when computing high reliability. An alternative reliability computation procedure is examined involving determination of a lower bound on the reliability values using extreme value distributions. This procedure reduces the possibility of obtaining nonconservative reliability estimates. Results indicated the method can provide conservative bounds when computing high reliability.

  16. Sustainable weight loss among overweight and obese lactating women is achieved with an energy-reduced diet in line with dietary recommendations: results from the LEVA randomized controlled trial.

    PubMed

    Bertz, Fredrik; Winkvist, Anna; Brekke, Hilde K

    2015-01-01

    The aim of this study was to evaluate dietary changes during and after a dietary treatment shown to result in significant and sustained weight loss among lactating overweight and obese women. This is crucial before clinical implementation. Data were collected from the LEVA (in Swedish: Livsstil för Effektiv Viktminskning under Amning [Lifestyle for Effective Weight Loss During Lactation]) randomized controlled factorial trial with a 12-week intervention and a 1-year follow up. At 10 to 14 weeks postpartum, 68 lactating Swedish women with a prepregnancy body mass index (calculated as kg/m(2)) of 25 to 35 were randomized to structured dietary treatment, physical exercise treatment, combined treatment, or usual care (controls) for a 12-week intervention, with a 1-year follow-up. Dietary intake was assessed with 4-day weighed dietary records. Recruitment took place between 2007 and 2010. The main outcome measures were changes in macro- and micronutrient intake from baseline to 12 weeks and 1 year. Main and interaction effects of the treatments were analyzed by a 2×2 factorial approach using a General Linear Model adjusted for relevant covariates (baseline intake and estimated underreporting). It was found that at baseline, the women had an intake of fat and sucrose above, and an intake of total carbohydrates and fiber below, recommended levels. At 12 weeks and 1 year, the dietary treatment led to reduced intake of energy (P<0.001 and P=0.005, respectively), fat (both P values <0.001), and sucrose (P<0.001 and P=0.050). At 12 weeks, total carbohydrates were reduced (P<0.001). A majority of women in all groups reported low intakes of vitamin D, folate, and/or iron. In conclusion, a novel dietary treatment led to reduced intake of fat and carbohydrates. Diet composition changed to decreased proportions of fat and sucrose, and increased proportions of complex carbohydrates, protein and fiber. Weight loss through dietary treatment was achieved with a diet in line with

  17. LAMPF reliability history and program

    SciTech Connect

    van Dyck, O.

    1994-09-01

    Many years of service of the 800-MeV LAMPF H{sup +}/H{sup {minus}} linac offers the opportunity to evaluate the long-term reliability characteristics of a high-power machine, which with up to 800-kW beam power available is as close to an ADTT machine as exists in the world today. Records from the last 15 years of operation were analyzed for trends and areas of deteriorating reliability or disproportionate downtime and used to support engineering judgment on facility refurbishment to regain beam availability. This round of analysis has helped define a further level of detail and automation to be implemented in availability recording. Interesting features which emerge from the history include a clear measurement of the lower availability in the first operating cycle following extended maintenance periods, and a consistent picture of the highest availability to be expected in extended operating periods with the facility as used and maintained. The results provide a starting point for informed discussion of reliability goals.

  18. Accessibility, reliability, and usability of neurosurgical resources.

    PubMed

    Agarwal, Nitin; Kommana, Sumana S; Hansberry, David R; Kashkoush, Ahmed I; Friedlander, Robert M; Lunsford, L Dade

    2017-04-01

    OBJECTIVE Closing the knowledge gap that exists between patients and health care providers is essential and is facilitated by easy access to patient education materials. Although such information has the potential to be an effective resource, it must be written in a user-friendly and understandable manner, especially when such material pertains to specialized and highly technical fields such as neurological surgery. The authors evaluated the accessibility, usability, and reliability of current educational resources provided by the American Association of Neurological Surgeons (AANS), Healthwise, and the National Institute for Neurological Disorders and Stroke (NINDS). METHODS Online neurosurgical patient education information provided by AANS, Healthwise, and NINDS was evaluated using the LIDA scale, a website quality assessment tool, by medical professionals and nonmedical professionals. A high achieving score is regarded as 90% or greater using the LIDA scale. RESULTS Accessibility scores were 76.7% (AANS), 83.3% (Healthwise), and 75.0% (NINDS). Average usability scores for the AANS, Healthwise, and NINDS were 73.3%, 82.6%, and 82.9%, respectively, when evaluated by medical professionals and 78.5%, 80.7%, and 75.9%, respectively, for nonmedical professionals, respectively. Average reliability scores were 58.5%, 53.3%, 72.6%, respectively, for medical professionals and 70.4%, 66.7%, and 78.5%, respectively, for nonmedical professionals when evaluating the AANS, Healthwise, and NINDS websites. CONCLUSIONS Although organizations like AANS, Healthwise, and NINDS should be commended for their ongoing commitment to provide health care-oriented materials, modification of this material is suggested to improve the patient education value.

  19. 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

  20. Storage Reliability of Missile Materiel Program. Missile Materiel Reliability Prediction Handbook - Parts Count Prediction

    DTIC Science & Technology

    1978-02-01

    OF MISSILE MATERIEL PROGRAM ,. MISSILE MATERIEL RELIABILITY PREDICTION HANDBOOK + "ARTS COUNT PREDICTION LC-78-1 FEBRUARY 1978 Prepared by: Dennis F...data for predicting the reliability of missile systems based on a "parts count" approach. The handbook is a result of a program whosa objective is the...has been extracted from existing reliability prediction sources. For more informations, contactz Commaz • •r U. S. h. ,y Missile R&D Command ATTN

  1. Ultra Reliable Closed Loop Life Support for Long Space Missions

    NASA Technical Reports Server (NTRS)

    Jones, Harry W.; Ewert, Michael K.

    2010-01-01

    Spacecraft human life support systems can achieve ultra reliability by providing sufficient spares to replace all failed components. The additional mass of spares for ultra reliability is approximately equal to the original system mass, provided that the original system reliability is not too low. Acceptable reliability can be achieved for the Space Shuttle and Space Station by preventive maintenance and by replacing failed units. However, on-demand maintenance and repair requires a logistics supply chain in place to provide the needed spares. In contrast, a Mars or other long space mission must take along all the needed spares, since resupply is not possible. Long missions must achieve ultra reliability, a very low failure rate per hour, since they will take years rather than weeks and cannot be cut short if a failure occurs. Also, distant missions have a much higher mass launch cost per kilogram than near-Earth missions. Achieving ultra reliable spacecraft life support systems with acceptable mass will require a well-planned and extensive development effort. Analysis must determine the reliability requirement and allocate it to subsystems and components. Ultra reliability requires reducing the intrinsic failure causes, providing spares to replace failed components and having "graceful" failure modes. Technologies, components, and materials must be selected and designed for high reliability. Long duration testing is needed to confirm very low failure rates. Systems design should segregate the failure causes in the smallest, most easily replaceable parts. The system must be designed, developed, integrated, and tested with system reliability in mind. Maintenance and reparability of failed units must not add to the probability of failure. The overall system must be tested sufficiently to identify any design errors. A program to develop ultra reliable space life support systems with acceptable mass should start soon since it must be a long term effort.

  2. a Reliability Evaluation System of Association Rules

    NASA Astrophysics Data System (ADS)

    Chen, Jiangping; Feng, Wanshu; Luo, Minghai

    2016-06-01

    In mining association rules, the evaluation of the rules is a highly important work because it directly affects the usability and applicability of the output results of mining. In this paper, the concept of reliability was imported into the association rule evaluation. The reliability of association rules was defined as the accordance degree that reflects the rules of the mining data set. Such degree contains three levels of measurement, namely, accuracy, completeness, and consistency of rules. To show its effectiveness, the "accuracy-completeness-consistency" reliability evaluation system was applied to two extremely different data sets, namely, a basket simulation data set and a multi-source lightning data fusion. Results show that the reliability evaluation system works well in both simulation data set and the actual problem. The three-dimensional reliability evaluation can effectively detect the useless rules to be screened out and add the missing rules thereby improving the reliability of mining results. Furthermore, the proposed reliability evaluation system is applicable to many research fields; using the system in the analysis can facilitate obtainment of more accurate, complete, and consistent association rules.

  3. Experts’ Opinions on the Reliability Gap and Some Practical Guidelines on Reliability Growth

    DTIC Science & Technology

    1988-09-01

    and found the ratio of the disparity to range 2 from 2.1:1 to 9.1:1 (38:231). Furthermore, Montemayor (54) studied the reliability gap between...Production, 17 October 1986. 54. Montemayor , A. J. "Achieved versus Predicted Mean-Time-Between-Failures (M.TBF)." The Boeing Company, D194-300341, March

  4. System Reliability for LED-Based Products

    SciTech Connect

    Davis, J Lynn; Mills, Karmann; Lamvik, Michael; Yaga, Robert; Shepherd, Sarah D; Bittle, James; Baldasaro, Nick; Solano, Eric; Bobashev, Georgiy; Johnson, Cortina; Evans, Amy

    2014-04-07

    Results from accelerated life tests (ALT) on mass-produced commercially available 6” downlights are reported along with results from commercial LEDs. The luminaires capture many of the design features found in modern luminaires. In general, a systems perspective is required to understand the reliability of these devices since LED failure is rare. In contrast, components such as drivers, lenses, and reflector are more likely to impact luminaire reliability than LEDs.

  5. CR reliability testing

    NASA Astrophysics Data System (ADS)

    Honeyman-Buck, Janice C.; Rill, Lynn; Frost, Meryll M.; Staab, Edward V.

    1998-07-01

    The purpose of this work was to develop a method for systematically testing the reliability of a CR system under realistic daily loads in a non-clinical environment prior to its clinical adoption. Once digital imaging replaces film, it will be very difficult to revert back should the digital system become unreliable. Prior to the beginning of the test, a formal evaluation was performed to set the benchmarks for performance and functionality. A formal protocol was established that included all the 62 imaging plates in the inventory for each 24-hour period in the study. Imaging plates were exposed using different combinations of collimation, orientation, and SID. Anthropomorphic phantoms were used to acquire images of different sizes. Each combination was chosen randomly to simulate the differences that could occur in clinical practice. The tests were performed over a wide range of times with batches of plates processed to simulate the temporal constraints required by the nature of portable radiographs taken in the Intensive Care Unit (ICU). Current patient demographics were used for the test studies so automatic routing algorithms could be tested. During the test, only three minor reliability problems occurred, two of which were not directly related to the CR unit. One plate was discovered to cause a segmentation error that essentially reduced the image to only black and white with no gray levels. This plate was removed from the inventory to be replaced. Another problem was a PACS routing problem that occurred when the DICOM server with which the CR was communicating had a problem with disk space. The final problem was a network printing failure to the laser cameras. Although the units passed the reliability test, problems with interfacing to workstations were discovered. The two issues that were identified were the interpretation of what constitutes a study for CR and the construction of the look-up table for a proper gray scale display.

  6. Ultimately Reliable Pyrotechnic Systems

    NASA Technical Reports Server (NTRS)

    Scott, John H.; Hinkel, Todd

    2015-01-01

    This paper presents the methods by which NASA has designed, built, tested, and certified pyrotechnic devices for high reliability operation in extreme environments and illustrates the potential applications in the oil and gas industry. NASA's extremely successful application of pyrotechnics is built upon documented procedures and test methods that have been maintained and developed since the Apollo Program. Standards are managed and rigorously enforced for performance margins, redundancy, lot sampling, and personnel safety. The pyrotechnics utilized in spacecraft include such devices as small initiators and detonators with the power of a shotgun shell, detonating cord systems for explosive energy transfer across many feet, precision linear shaped charges for breaking structural membranes, and booster charges to actuate valves and pistons. NASA's pyrotechnics program is one of the more successful in the history of Human Spaceflight. No pyrotechnic device developed in accordance with NASA's Human Spaceflight standards has ever failed in flight use. NASA's pyrotechnic initiators work reliably in temperatures as low as -420 F. Each of the 135 Space Shuttle flights fired 102 of these initiators, some setting off multiple pyrotechnic devices, with never a failure. The recent landing on Mars of the Opportunity rover fired 174 of NASA's pyrotechnic initiators to complete the famous '7 minutes of terror.' Even after traveling through extreme radiation and thermal environments on the way to Mars, every one of them worked. These initiators have fired on the surface of Titan. NASA's design controls, procedures, and processes produce the most reliable pyrotechnics in the world. Application of pyrotechnics designed and procured in this manner could enable the energy industry's emergency equipment, such as shutoff valves and deep-sea blowout preventers, to be left in place for years in extreme environments and still be relied upon to function when needed, thus greatly enhancing

  7. Quality control and reliability of reported doses.

    PubMed

    Stadtmann, H; Figel, Markus; Kamenopoulou, V; Kluszczynski, D; Roed, H; Van Dijk, J

    2004-01-01

    Results of performance tests verifying the dosimetric properties of dosimetric systems are published in various reports (e.g. IAEA and EURADOS). However, there is hardly any information in the open literature relating to the uncertainty in a dose measurement or in the annual dose, which is increased by failure of the evaluation or data management system, damage of the dosemeter itself or by the loss of dosemeter. In this article, an attempt is made to estimate the importance of the above-mentioned conditions. This is achieved by sending questionnaires to about 200 approved dosimetric services in Europe. In total 88 questionnaires were returned and analysed. In the questionnaires, the frequency of occurrence of the various error conditions were investigated. Participants were also asked to evaluate the impact of the error condition from a dosimetric point of view and what countermeasures are taken. The article summarises all responses and compares different sources of errors according to their impact on the uncertainty of the resulting dose and gives a comprehensive overview on quality control actions and reliability on reported doses from European dosimetric services.

  8. Gearbox Reliability Collaborative Phase 3 Gearbox 2 Test Plan

    SciTech Connect

    Link, H.; Keller, J.; Guo, Y.; McNiff, B.

    2013-04-01

    Gearboxes in wind turbines have not been achieving their expected design life even though they commonly meet or exceed the design criteria specified in current design standards. One of the basic premises of the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) is that the low gearbox reliability results from the absence of critical elements in the design process or insufficient design tools. Key goals of the GRC are to improve design approaches and analysis tools and to recommend practices and test methods resulting in improved design standards for wind turbine gearboxes that lower the cost of energy (COE) through improved reliability. The GRC uses a combined gearbox testing, modeling and analysis approach, along with a database of information from gearbox failures collected from overhauls and investigation of gearbox condition monitoring techniques to improve wind turbine operations and maintenance practices. Testing of Gearbox 2 (GB2) using the two-speed turbine controller that has been used in prior testing. This test series will investigate non-torque loads, high-speed shaft misalignment, and reproduction of field conditions in the dynamometer. This test series will also include vibration testing using an eddy-current brake on the gearbox's high speed shaft.

  9. Reliability Growth Prediction

    DTIC Science & Technology

    1986-09-01

    the Duane model because: *e ’he reliability gSod’ data analyzed were reflective of a single Lesr- for • each equipment as opposed to a series of zest ...fabrication) and costs wbich are a function of test length (e.g., chamber operations). A life -cycle cost model, Ref. 14 for example, can be exercised tc...J. Gibson and K. K. Mcain APPROVED FOR FUBLIC RE1EAS NI ODSrRUTIG1,N UY-LUlHfF :-:-4 ROME AIR DEVELOPMENT CENTER Air Force Systems Command Griffiss

  10. Blade reliability collaborative :

    SciTech Connect

    Ashwill, Thomas D.; Ogilvie, Alistair B.; Paquette, Joshua A.

    2013-04-01

    The Blade Reliability Collaborative (BRC) was started by the Wind Energy Technologies Department of Sandia National Laboratories and DOE in 2010 with the goal of gaining insight into planned and unplanned O&M issues associated with wind turbine blades. A significant part of BRC is the Blade Defect, Damage and Repair Survey task, which will gather data from blade manufacturers, service companies, operators and prior studies to determine details about the largest sources of blade unreliability. This report summarizes the initial findings from this work.

  11. Ferrite logic reliability study

    NASA Technical Reports Server (NTRS)

    Baer, J. A.; Clark, C. B.

    1973-01-01

    Development and use of digital circuits called all-magnetic logic are reported. In these circuits the magnetic elements and their windings comprise the active circuit devices in the logic portion of a system. The ferrite logic device belongs to the all-magnetic class of logic circuits. The FLO device is novel in that it makes use of a dual or bimaterial ferrite composition in one physical ceramic body. This bimaterial feature, coupled with its potential for relatively high speed operation, makes it attractive for high reliability applications. (Maximum speed of operation approximately 50 kHz.)

  12. Scaled CMOS Technology Reliability Users Guide

    NASA Technical Reports Server (NTRS)

    White, Mark

    2010-01-01

    The desire to assess the reliability of emerging scaled microelectronics technologies through faster reliability trials and more accurate acceleration models is the precursor for further research and experimentation in this relevant field. The effect of semiconductor scaling on microelectronics product reliability is an important aspect to the high reliability application user. From the perspective of a customer or user, who in many cases must deal with very limited, if any, manufacturer's reliability data to assess the product for a highly-reliable application, product-level testing is critical in the characterization and reliability assessment of advanced nanometer semiconductor scaling effects on microelectronics reliability. A methodology on how to accomplish this and techniques for deriving the expected product-level reliability on commercial memory products are provided.Competing mechanism theory and the multiple failure mechanism model are applied to the experimental results of scaled SDRAM products. Accelerated stress testing at multiple conditions is applied at the product level of several scaled memory products to assess the performance degradation and product reliability. Acceleration models are derived for each case. For several scaled SDRAM products, retention time degradation is studied and two distinct soft error populations are observed with each technology generation: early breakdown, characterized by randomly distributed weak bits with Weibull slope (beta)=1, and a main population breakdown with an increasing failure rate. Retention time soft error rates are calculated and a multiple failure mechanism acceleration model with parameters is derived for each technology. Defect densities are calculated and reflect a decreasing trend in the percentage of random defective bits for each successive product generation. A normalized soft error failure rate of the memory data retention time in FIT/Gb and FIT/cm2 for several scaled SDRAM generations is

  13. Operational reliability of standby safety systems

    SciTech Connect

    Grant, G.M.; Atwood, C.L.; Gentillon, C.D.

    1995-04-01

    The Idaho National Engineering Laboratory (INEL) is evaluating the operational reliability of several risk-significant standby safety systems based on the operating experience at US commercial nuclear power plants from 1987 through 1993. The reliability assessed is the probability that the system will perform its Probabilistic Risk Assessment (PRA) defined safety function. The quantitative estimates of system reliability are expected to be useful in risk-based regulation. This paper is an overview of the analysis methods and the results of the high pressure coolant injection (HPCI) system reliability study. Key characteristics include (1) descriptions of the data collection and analysis methods, (2) the statistical methods employed to estimate operational unreliability, (3) a description of how the operational unreliability estimates were compared with typical PRA results, both overall and for each dominant failure mode, and (4) a summary of results of the study.

  14. Development of brain systems for nonsymbolic numerosity and the relationship to formal math academic achievement.

    PubMed

    Haist, Frank; Wazny, Jarnet H; Toomarian, Elizabeth; Adamo, Maha

    2015-02-01

    A central question in cognitive and educational neuroscience is whether brain operations supporting nonlinguistic intuitive number sense (numerosity) predict individual acquisition and academic achievement for symbolic or "formal" math knowledge. Here, we conducted a developmental functional magnetic resonance imaging (MRI) study of nonsymbolic numerosity task performance in 44 participants including 14 school age children (6-12 years old), 14 adolescents (13-17 years old), and 16 adults and compared a brain activity measure of numerosity precision to scores from the Woodcock-Johnson III Broad Math index of math academic achievement. Accuracy and reaction time from the numerosity task did not reliably predict formal math achievement. We found a significant positive developmental trend for improved numerosity precision in the parietal cortex and intraparietal sulcus specifically. Controlling for age and overall cognitive ability, we found a reliable positive relationship between individual math achievement scores and parietal lobe activity only in children. In addition, children showed robust positive relationships between math achievement and numerosity precision within ventral stream processing areas bilaterally. The pattern of results suggests a dynamic developmental trajectory for visual discrimination strategies that predict the acquisition of formal math knowledge. In adults, the efficiency of visual discrimination marked by numerosity acuity in ventral occipital-temporal cortex and hippocampus differentiated individuals with better or worse formal math achievement, respectively. Overall, these results suggest that two different brain systems for nonsymbolic numerosity acuity may contribute to individual differences in math achievement and that the contribution of these systems differs across development.

  15. 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.

  16. Schoolbook Texts: Behavioral Achievement Priming in Math and Language.

    PubMed

    Engeser, Stefan; Baumann, Nicola; Baum, Ingrid

    2016-01-01

    Prior research found reliable and considerably strong effects of semantic achievement primes on subsequent performance. In order to simulate a more natural priming condition to better understand the practical relevance of semantic achievement priming effects, running texts of schoolbook excerpts with and without achievement primes were used as priming stimuli. Additionally, we manipulated the achievement context; some subjects received no feedback about their achievement and others received feedback according to a social or individual reference norm. As expected, we found a reliable (albeit small) positive behavioral priming effect of semantic achievement primes on achievement in math (Experiment 1) and language tasks (Experiment 2). Feedback moderated the behavioral priming effect less consistently than we expected. The implication that achievement primes in schoolbooks can foster performance is discussed along with general theoretical implications.

  17. Schoolbook Texts: Behavioral Achievement Priming in Math and Language

    PubMed Central

    Engeser, Stefan; Baumann, Nicola; Baum, Ingrid

    2016-01-01

    Prior research found reliable and considerably strong effects of semantic achievement primes on subsequent performance. In order to simulate a more natural priming condition to better understand the practical relevance of semantic achievement priming effects, running texts of schoolbook excerpts with and without achievement primes were used as priming stimuli. Additionally, we manipulated the achievement context; some subjects received no feedback about their achievement and others received feedback according to a social or individual reference norm. As expected, we found a reliable (albeit small) positive behavioral priming effect of semantic achievement primes on achievement in math (Experiment 1) and language tasks (Experiment 2). Feedback moderated the behavioral priming effect less consistently than we expected. The implication that achievement primes in schoolbooks can foster performance is discussed along with general theoretical implications. PMID:26938446

  18. Key Reliability Drivers of Liquid Propulsion Engines and A Reliability Model for Sensitivity Analysis

    NASA Technical Reports Server (NTRS)

    Huang, Zhao-Feng; Fint, Jeffry A.; Kuck, Frederick M.

    2005-01-01

    This paper is to address the in-flight reliability of a liquid propulsion engine system for a launch vehicle. We first establish a comprehensive list of system and sub-system reliability drivers for any liquid propulsion engine system. We then build a reliability model to parametrically analyze the impact of some reliability parameters. We present sensitivity analysis results for a selected subset of the key reliability drivers using the model. Reliability drivers identified include: number of engines for the liquid propulsion stage, single engine total reliability, engine operation duration, engine thrust size, reusability, engine de-rating or up-rating, engine-out design (including engine-out switching reliability, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction), propellant specific hazards, engine start and cutoff transient hazards, engine combustion cycles, vehicle and engine interface and interaction hazards, engine health management system, engine modification, engine ground start hold down with launch commit criteria, engine altitude start (1 in. start), Multiple altitude restart (less than 1 restart), component, subsystem and system design, manufacturing/ground operation support/pre and post flight check outs and inspection, extensiveness of the development program. We present some sensitivity analysis results for the following subset of the drivers: number of engines for the propulsion stage, single engine total reliability, engine operation duration, engine de-rating or up-rating requirements, engine-out design, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction, and engine health management system implementation (basic redlines and more advanced health management systems).

  19. Systems reliability analysis for the national ignition facility

    SciTech Connect

    Majumdar, K.C.; Annese, C.E.; MacIntyre, A.T.; Sicherman, A.

    1996-06-12

    A Reliability, Availability and Maintainability (RAM) analysis was initiated for the National Ignition Facility (NIF). The NIF is an inertial confinement fusion research facility designed to achieve controlled thermonuclear reaction; the preferred site for the NIF is the Lawrence Livermore National Laboratory (LLNL). The NIF RAM analysis has three purposes: (1) to allocate top level reliability and availability goals for the systems, (2) to develop an operability model for optimum maintainability, and (3) to determine the achievability of the allocated goals of the RAM parameters for the NIF systems and the facility operation as a whole. An allocation model assigns the reliability and availability goals for front line and support systems by a top-down approach; reliability analysis uses a bottom-up approach to determine the system reliability and availability from component level to system level.

  20. Integrated circuit reliability testing

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Sayah, Hoshyar R. (Inventor)

    1990-01-01

    A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the measured length of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor. The percentage by which the measured length exceeds the design length, at which the integrated circuit will be discarded, depends on the required reliability of the integrated circuit.

  1. Integrated circuit reliability testing

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Sayah, Hoshyar R. (Inventor)

    1988-01-01

    A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the measured length of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor. The percentage by which the measured length exceeds the design length, at which the integrated circuit will be discarded, depends on the required reliability of the integrated circuit.

  2. The Reliability of Neurons

    PubMed Central

    Bullock, Theodore Holmes

    1970-01-01

    The prevalent probabilistic view is virtually untestable; it remains a plausible belief. The cases usually cited can not be taken as evidence for it. Several grounds for this conclusion are developed. Three issues are distinguished in an attempt to clarify a murky debate: (a) the utility of probabilistic methods in data reduction, (b) the value of models that assume indeterminacy, and (c) the validity of the inference that the nervous system is largely indeterministic at the neuronal level. No exception is taken to the first two; the second is a private heuristic question. The third is the issue to which the assertion in the first two sentences is addressed. Of the two kinds of uncertainty, statistical mechanical (= practical unpredictability) as in a gas, and Heisenbergian indeterminancy, the first certainly exists, the second is moot at the neuronal level. It would contribute to discussion to recognize that neurons perform with a degree of reliability. Although unreliability is difficult to establish, to say nothing of measure, evidence that some neurons have a high degree of reliability, in both connections and activity is increasing greatly. An example is given from sternarchine electric fish. PMID:5462670

  3. 'No delays achiever'.

    PubMed

    2007-05-01

    The latest version of the NHS Institute for Innovation and Improvement's 'no delays achiever', a web based tool created to help NHS organisations achieve the 18-week target for GP referrals to first treatment, is available at www.nodelaysachiever.nhs.uk.

  4. Vicarious Achievement Orientation.

    ERIC Educational Resources Information Center

    Leavitt, Harold J.; And Others

    This study tests hypotheses about achievement orientation, particularly vicarious achievement. Undergraduate students (N=437) completed multiple-choice questionnaires, indicating likely responses of one person to the success of another. The sex of succeeder and observer, closeness of relationship, and setting (medical school or graduate school of…

  5. Heritability of Creative Achievement

    ERIC Educational Resources Information Center

    Piffer, Davide; Hur, Yoon-Mi

    2014-01-01

    Although creative achievement is a subject of much attention to lay people, the origin of individual differences in creative accomplishments remain poorly understood. This study examined genetic and environmental influences on creative achievement in an adult sample of 338 twins (mean age = 26.3 years; SD = 6.6 years). Twins completed the Creative…

  6. Confronting the Achievement Gap

    ERIC Educational Resources Information Center

    Gardner, David

    2007-01-01

    This article talks about the large achievement gap between children of color and their white peers. The reasons for the achievement gap are varied. First, many urban minorities come from a background of poverty. One of the detrimental effects of growing up in poverty is receiving inadequate nourishment at a time when bodies and brains are rapidly…

  7. Achievement-Based Resourcing.

    ERIC Educational Resources Information Center

    Fletcher, Mike; And Others

    1992-01-01

    This collection of seven articles examines achievement-based resourcing (ABR), the concept that the funding of educational institutions should be linked to their success in promoting student achievement, with a focus on the application of ABR to postsecondary education in the United Kingdom. The articles include: (1) "Introduction" (Mick…

  8. States Address Achievement Gaps.

    ERIC Educational Resources Information Center

    Christie, Kathy

    2002-01-01

    Summarizes 2 state initiatives to address the achievement gap: North Carolina's report by the Advisory Commission on Raising Achievement and Closing Gaps, containing an 11-point strategy, and Kentucky's legislation putting in place 10 specific processes. The North Carolina report is available at www.dpi.state.nc.us.closingthegap; Kentucky's…

  9. B-52 stability augmentation system reliability

    NASA Technical Reports Server (NTRS)

    Bowling, T. C.; Key, L. W.

    1976-01-01

    The B-52 SAS (Stability Augmentation System) was developed and retrofitted to nearly 300 aircraft. It actively controls B-52 structural bending, provides improved yaw and pitch damping through sensors and electronic control channels, and puts complete reliance on hydraulic control power for rudder and elevators. The system has experienced over 300,000 flight hours and has exhibited service reliability comparable to the results of the reliability test program. Development experience points out numerous lessons with potential application in the mechanization and development of advanced technology control systems of high reliability.

  10. Apollo experience report: Reliability and quality assurance

    NASA Technical Reports Server (NTRS)

    Sperber, K. P.

    1973-01-01

    The reliability of the Apollo spacecraft resulted from the application of proven reliability and quality techniques and from sound management, engineering, and manufacturing practices. Continual assessment of these techniques and practices was made during the program, and, when deficiencies were detected, adjustments were made and the deficiencies were effectively corrected. The most significant practices, deficiencies, adjustments, and experiences during the Apollo Program are described in this report. These experiences can be helpful in establishing an effective base on which to structure an efficient reliability and quality assurance effort for future space-flight programs.

  11. Estimating the Reliability of a Soyuz Spacecraft Mission

    NASA Technical Reports Server (NTRS)

    Lutomski, Michael G.; Farnham, Steven J., II; Grant, Warren C.

    2010-01-01

    Once the US Space Shuttle retires in 2010, the Russian Soyuz Launcher and Soyuz Spacecraft will comprise the only means for crew transportation to and from the International Space Station (ISS). The U.S. Government and NASA have contracted for crew transportation services to the ISS with Russia. The resulting implications for the US space program including issues such as astronaut safety must be carefully considered. Are the astronauts and cosmonauts safer on the Soyuz than the Space Shuttle system? Is the Soyuz launch system more robust than the Space Shuttle? Is it safer to continue to fly the 30 year old Shuttle fleet for crew transportation and cargo resupply than the Soyuz? Should we extend the life of the Shuttle Program? How does the development of the Orion/Ares crew transportation system affect these decisions? The Soyuz launcher has been in operation for over 40 years. There have been only two loss of life incidents and two loss of mission incidents. Given that the most recent incident took place in 1983, how do we determine current reliability of the system? Do failures of unmanned Soyuz rockets impact the reliability of the currently operational man-rated launcher? Does the Soyuz exhibit characteristics that demonstrate reliability growth and how would that be reflected in future estimates of success? NASA s next manned rocket and spacecraft development project is currently underway. Though the projects ultimate goal is to return to the Moon and then to Mars, the launch vehicle and spacecraft s first mission will be for crew transportation to and from the ISS. The reliability targets are currently several times higher than the Shuttle and possibly even the Soyuz. Can these targets be compared to the reliability of the Soyuz to determine whether they are realistic and achievable? To help answer these questions this paper will explore how to estimate the reliability of the Soyuz Launcher/Spacecraft system, compare it to the Space Shuttle, and its

  12. Reliability assessment of home health care services.

    PubMed

    Spyrou, Stergiani; Bamidis, Panagiotis; Kilintzis, Vassilis; Lekka, Irini; Maglaveras, Nicos; Pappas, Costas

    2007-01-01

    In this paper, a model of reliability assessment of services in Home Health Care Delivery is presented. Reliability is an important quality dimension for services and is included in non-functional requirements of a system. A stochastic Markov model for reliability assessment is applied to patient communication services, in the field of home health care delivery. The methodology includes the specification of scenarios, the definition of failures in scenarios as well as the application of the analytical model. The results of the methodology reveal the critical states of the Home Health Care System and recommendations for improvement of the services are proposed. The model gives valuable results in predicting service reliability and, independently of the error types, it can be applied to all fields of Regional Health Network (RHN).

  13. Maximized reliability with minimal cross-layer cutset under arbitrary link failure probability in multilayer optical networks

    NASA Astrophysics Data System (ADS)

    Zhao, Yongli; Chen, Bowen; Zhang, Jie

    2016-09-01

    We investigate the maximized cross-layer reliability under arbitrary link failure probability in multilayer optical networks. A concept of minimal cross-layer cutset is first defined and a reliability model with arbitrary physical link failure probability is built in the multilayer optical networks. In order to reduce the scale of cutset enumeration, we introduce two metrics to estimate cross-layer reliability, i.e., the minimum cross-layer node reliability and the minimum cross-layer edge reliability (MCER). Furthermore, we develop two linear programming (LP) models and two heuristic algorithms to maximize the cross-layer reliability of multilayer optical networks, i.e., the minimum shared-risk mapping algorithm and the least shared failure probability algorithm. Simulation results show that: (i) the cross-layer reliability of the two proposed algorithms is close to the LP solutions under logical networks with different sizes, which achieves better results in terms of additional resources utilization compared with the shortest path algorithm; (ii) less difference between the results of our proposed algorithms and the results of the shortest path algorithm is accompanied by a small standard deviation of failure probability distribution. Moreover, the superiority of our proposed algorithms becomes more remarkable with the increasing of the standard deviation.

  14. Achievability for telerobotic systems

    NASA Astrophysics Data System (ADS)

    Kress, Reid L.; Draper, John V.; Hamel, William R.

    2001-02-01

    Methods are needed to improve the capabilities of autonomous robots to perform tasks that are difficult for contemporary robots, and to identify those tasks that robots cannot perform. Additionally, in the realm of remote handling, methods are needed to assess which tasks and/or subtasks are candidates for automation. We are developing a new approach to understanding the capability of autonomous robotic systems. This approach uses formalized methods for determining the achievability of tasks for robots, that is, the likelihood that an autonomous robot or telerobot can successfully complete a particular task. Any autonomous system may be represented in achievability space by the volume describing that system's capabilities within the 3-axis space delineated by perception, cognition, and action. This volume may be thought of as a probability density with achievability decreasing as the distance from the centroid of the volume increases. Similarly, any task may be represented within achievability space. However, as tasks have more finite requirements for perception, cognition, and action, each may be represented as a point (or, more accurately, as a small sphere) within achievability space. Analysis of achievability can serve to identify, a priori, the survivability of robotic systems and the likelihood of mission success; it can be used to plan a mission or portions of a mission; it can be used to modify a mission plan to accommodate unpredicted occurrences; it can also serve to identify needs for modifications to robotic systems or tasks to improve achievability. .

  15. Testing for PV Reliability (Presentation)

    SciTech Connect

    Kurtz, S.; Bansal, S.

    2014-09-01

    The DOE SUNSHOT workshop is seeking input from the community about PV reliability and how the DOE might address gaps in understanding. This presentation describes the types of testing that are needed for PV reliability and introduces a discussion to identify gaps in our understanding of PV reliability testing.

  16. Making Reliability Arguments in Classrooms

    ERIC Educational Resources Information Center

    Parkes, Jay; Giron, Tilia

    2006-01-01

    Reliability methodology needs to evolve as validity has done into an argument supported by theory and empirical evidence. Nowhere is the inadequacy of current methods more visible than in classroom assessment. Reliability arguments would also permit additional methodologies for evidencing reliability in classrooms. It would liberalize methodology…

  17. High reliability plastic packaging for microelectronics

    SciTech Connect

    Sweet, J.N.; Peterson, D.W.; Hsia, A.H.; Tuck, M.

    1997-07-01

    Goal was Assembly Test Chips (ATCs) which could be used for evaluating plastic encapsulation technologies. Circuits were demonstrated for measuring Au-Al wirebond and Al metal corrosion failure rates during accelerated temperature and humidity testing. The test circuits on the ATC02.5 chip were very sensitive to extrinsic or processing induced failure rates. Accelerated aging experiments were conducted with unpassivated triple track Al structures on the ATC02.6 chip; the unpassivated tracks were found to be very sensitive to particulate contamination. Some modifications to existing circuitry were suggested. The piezoresistive stress sensing circuitry designed for the ATC04 test chip was found suitable for determining the change in the state of mechanical stress at the die when both initial and final measurements were made near room temperature (RT). Attempt to measure thermal stress between RT and a typical polymer glass transition temperature failed because of excessive die resistor- substrate leakage currents at the high temperature end; suitable circuitry changes were developed to overcome this problem. One temperature and humidity experiment was conducted with Sandia developed static radom access memory parts to examine non-corrosion CMOS failures; this objective was not achieved, but corrosion failure at the metal to Si contacts on the die surface could be detected. This 2-year effort resulted in new designs for test circuits which could be used on an advanced ATC for reliability assessment in Defense Programs electronics development projects.

  18. Distribution and reliability in a multiprocessor operating system

    SciTech Connect

    Sindhu, P.S.

    1984-01-01

    This thesis explores whether distributed hardware can be used to build reliable systems that are practical. It deals mostly with issues in the design and construction of the MEDUSA operating system, built to run of the distributed multiprocessor Cm. The goal is to exploit the redundancy, physical distribution, and powerful communication facilities within Cm to produce a robust system - one that can function satisfactorily in spite of hardware failure, bad data, heavy demands on its services, and other disruptive occurrences. The thesis demonstrates that, given appropriate hardware, it is possible to provide robustness without significantly sacrificing performance or greatly increasing complexity. Factors important to this success were 1) the treatment of reliability as a probabilistic rather than an absolute guarantee, which resulted in a structure whose components explicitly acknowledge and cope with failures in one another; 2) the adoption of a systematic approach to exception processing, which made the complexity of recovery manageable; and 3) the exploitation of system knowledge in the design of reliability mechanisms, which made it possible to achieve robustness while retaining good normal-case performance.

  19. Technology mapping for hot-carrier reliability enhancement

    NASA Astrophysics Data System (ADS)

    Chen, Zhan; Koren, Israel

    1997-09-01

    As semiconductor devices enter the deep sub-micron era, reliability has become a major issue and challenge in VLSI design. Among all the failure mechanisms, hot-carrier effect is one of those which have the most significant impact on the long-term reliability of high-density VLSI circuits. In this paper, we address the problem of minimizing hot-carrier effect during the technology mapping stage of VLSI logic synthesis. We first present a logic-level hot-carrier model, and then, based on this model, we propose a technology mapping algorithm for hot-carrier effect minimization. The proposed algorithm has been implemented in the framework of the Berkeley logic optimization package SIS. Our results show that an average of 29. 1% decrease in hot-carrier effect can be achieved by carefully choosing logic gates from cell libraries to implement given logic functions for a set of benchmarks. It has also been observed that the best design for hot-carrier effect minimization does not necessarily coincide with the best design for low power, which has long been considered as a rough measure for VLSI reliability.

  20. Maximally reliable spatial filtering of steady state visual evoked potentials.

    PubMed

    Dmochowski, Jacek P; Greaves, Alex S; Norcia, Anthony M

    2015-04-01

    Due to their high signal-to-noise ratio (SNR) and robustness to artifacts, steady state visual evoked potentials (SSVEPs) are a popular technique for studying neural processing in the human visual system. SSVEPs are conventionally analyzed at individual electrodes or linear combinations of electrodes which maximize some variant of the SNR. Here we exploit the fundamental assumption of evoked responses--reproducibility across trials--to develop a technique that extracts a small number of high SNR, maximally reliable SSVEP components. This novel spatial filtering method operates on an array of Fourier coefficients and projects the data into a low-dimensional space in which the trial-to-trial spectral covariance is maximized. When applied to two sample data sets, the resulting technique recovers physiologically plausible components (i.e., the recovered topographies match the lead fields of the underlying sources) while drastically reducing the dimensionality of the data (i.e., more than 90% of the trial-to-trial reliability is captured in the first four components). Moreover, the proposed technique achieves a higher SNR than that of the single-best electrode or the Principal Components. We provide a freely-available MATLAB implementation of the proposed technique, herein termed "Reliable Components Analysis".

  1. Reliability and properties of ground Y-TZP-zirconia ceramics.

    PubMed

    Luthardt, R G; Holzhüter, M; Sandkuhl, O; Herold, V; Schnapp, J D; Kuhlisch, E; Walter, M

    2002-07-01

    Yttria-stabilized zirconia ceramics is a high-performance material with excellent biocompatibility and mechanical properties, which suggest its suitability for posterior fixed partial dentures. The hypothesis under examination is that the strength and reliability of Y-TZP zirconia ceramics are affected by the inner surface grinding of crowns, and vary with the grinding parameter. Flexural strength, surface roughness, and fracture toughness were determined on samples machined by face and peripheral grinding with varied feed velocities and cutting depths. Results have been compared with those on lapped samples. Analysis of variance and Weibull parameter were used for statistical analysis. It was found that inner surface grinding significantly reduces the strength and reliability of Y-TZP zirconia compared with the lapped control sample. Co-analysis of flexural strength, Weibull parameter, and fracture toughness showed counteracting effects of surface compressive stress and grinding-introduced surface flaws. In conclusion, grinding of Y-TZP needs to be optimized to achieve the CAD/CAM manufacture of all-ceramic restorations with improved strength and reliability.

  2. Reliability and availability studies in the RIA driver linac.

    SciTech Connect

    Lessner, E. S.; Ostroumov, P. N.; Physics

    2005-01-01

    The Rare Isotope Accelerator (RIA) facility will include various complex systems and must provide radioactive beams to many users simultaneously. The availability of radioactive beams for most experiments at the fully-commissioned facility should be as high as possible within design cost limitations. To make a realistic estimate of the achievable reliability a detailed analysis is required. The RIA driver linac is a complex machine containing a large number of superconducting (SC) resonators and capable of accelerating multiple-charge-state beams [1]. At the pre-CDR stage of the design it is essential to identify critical facility subsystem failures that can prevent the driver linac from operating. The reliability and availability of the driver linac were studied using expert information and data from operating machines such as ATLAS, APS, JLab, and LANL. Availability studies are performed with a Monte-Carlo simulation code previously applied to availability assessments of the NLC facility [2] and the results used to identify subsystem failures that most affect the availability and reliability of the RIA driver, and guide design iterations and component specifications to address identified problems.

  3. Gearbox Reliability Collaborative (GRC) Description and Loading

    SciTech Connect

    Oyague, F.

    2011-11-01

    This document describes simulated turbine load cases in accordance to the IEC 61400-1 Ed.3 standard, which is representative of the typical wind turbine design process. The information presented herein is intended to provide a broad understanding of the gearbox reliability collaborative 750kW drivetrain and turbine configuration. In addition, fatigue and ultimate strength drivetrain loads resulting from simulations are presented. This information provides the bases for the analytical work of the gearbox reliability collaborative effort.

  4. Analyzing network reliability using structural motifs.

    PubMed

    Khorramzadeh, Yasamin; Youssef, Mina; Eubank, Stephen; Mowlaei, Shahir

    2015-04-01

    This paper uses the reliability polynomial, introduced by Moore and Shannon in 1956, to analyze the effect of network structure on diffusive dynamics such as the spread of infectious disease. We exhibit a representation for the reliability polynomial in terms of what we call structural motifs that is well suited for reasoning about the effect of a network's structural properties on diffusion across the network. We illustrate by deriving several general results relating graph structure to dynamical phenomena.

  5. Production Facility System Reliability Analysis Report

    SciTech Connect

    Dale, Crystal Buchanan; Klein, Steven Karl

    2015-10-06

    This document describes the reliability, maintainability, and availability (RMA) modeling of the Los Alamos National Laboratory (LANL) design for the Closed Loop Helium Cooling System (CLHCS) planned for the NorthStar accelerator-based 99Mo production facility. The current analysis incorporates a conceptual helium recovery system, beam diagnostics, and prototype control system into the reliability analysis. The results from the 1000 hr blower test are addressed.

  6. A method for setting reliability performance criteria

    SciTech Connect

    Burns, K.J.; Turcotte, R.T.

    1996-08-01

    Reliability performance criteria are required for monitoring under the Maintenance Rule. This paper presents a probabilistic approach for establishing these performance criteria on a plant-specific basis. Results are presented for a number of case studies, and are summarized in terms of a deterministic formula. This formula was used to develop and document reliability performance criteria for all Maintenance Rule systems/subsystems at the Vermont Yankee Nuclear Power Station.

  7. Discrete Reliability Projection

    DTIC Science & Technology

    2014-12-01

    Defense, Handbook MIL - HDBK -189C, 2011 Hall, J. B., Methodology for Evaluating Reliability Growth Programs of Discrete Systems, Ph.D. thesis, University...pk,i ] · [ 1− (1− θ̆k) · ( N k · T )]k−m , (2.13) 5 2 Hall’s Model where m is the number of observed failure modes and d∗i estimates di (either based...Mode Failures FEF Ni d ∗ i 1 1 0.95 2 1 0.70 3 1 0.90 4 1 0.90 5 4 0.95 6 2 0.70 7 1 0.80 Using equations 2.1 and 2.2 we can calculate the failure

  8. Validity and reliability of Internet-based physiotherapy assessment for musculoskeletal disorders: a systematic review.

    PubMed

    Mani, Suresh; Sharma, Shobha; Omar, Baharudin; Paungmali, Aatit; Joseph, Leonard

    2017-04-01

    Purpose The purpose of this review is to systematically explore and summarise the validity and reliability of telerehabilitation (TR)-based physiotherapy assessment for musculoskeletal disorders. Method A comprehensive systematic literature review was conducted using a number of electronic databases: PubMed, EMBASE, PsycINFO, Cochrane Library and CINAHL, published between January 2000 and May 2015. The studies examined the validity, inter- and intra-rater reliabilities of TR-based physiotherapy assessment for musculoskeletal conditions were included. Two independent reviewers used the Quality Appraisal Tool for studies of diagnostic Reliability (QAREL) and the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool to assess the methodological quality of reliability and validity studies respectively. Results A total of 898 hits were achieved, of which 11 articles based on inclusion criteria were reviewed. Nine studies explored the concurrent validity, inter- and intra-rater reliabilities, while two studies examined only the concurrent validity. Reviewed studies were moderate to good in methodological quality. The physiotherapy assessments such as pain, swelling, range of motion, muscle strength, balance, gait and functional assessment demonstrated good concurrent validity. However, the reported concurrent validity of lumbar spine posture, special orthopaedic tests, neurodynamic tests and scar assessments ranged from low to moderate. Conclusion TR-based physiotherapy assessment was technically feasible with overall good concurrent validity and excellent reliability, except for lumbar spine posture, orthopaedic special tests, neurodynamic testa and scar assessment.

  9. Structural reliability of road accidents reconstruction.

    PubMed

    Wach, Wojciech

    2013-05-10

    Reconstruction of road accidents combines objective and subjective action. The former concerns science, the latter assessment of human behavior in the context of objective findings. It is not uncommon for experts equipped with an arsenal of tools to obtain similar results of calculations, but to present radically different conclusions about the cause of the accident. The use of sophisticated methods of uncertainty analysis does not guarantee improvement in quality of reconstruction, because, increasingly, the most serious source of reduced reliability of reconstruction is problems in logical inference. In the article the structure of uncertainty and reliability of accident reconstruction was described. A definition of reliability of road accident reconstruction based on the theory of conditional probability and Bayesian network, as a function of modeling, data and expert reliability (defined in the text) was proposed. The uncertainty of reconstruction was made dependent only on the uncertainty of the data. This separation makes it possible to conduct a qualitative and quantitative analysis of reconstruction reliability and to analyze its sensitivity to component parameters, independently of the uncertainty analysis. An example of calculation was presented. The proposed formalism constitutes a tool helpful to explain, among other things, the paradox of reliable reconstruction despite its uncertain results or unreliable reconstruction despite high precision of results. This approach is of great importance in the reconstruction of road accidents, which goes far beyond the analysis of a single, homogeneous subsystem.

  10. Culture and Achievement Motivation

    ERIC Educational Resources Information Center

    Maehr, Martin L.

    1974-01-01

    A framework is suggested for the cross-cultural study of motivation that stresses the importance of contextual conditions in eliciting achievement motivation and emphasizes cultural relativity in the definition of the concept. (EH)

  11. Achieving Salary Equity

    ERIC Educational Resources Information Center

    Nevill, Dorothy D.

    1975-01-01

    Three techniques are outlined for use by higher education institutions to achieve salary equity: salary prediction (using various statistical procedures), counterparting (comparing salaries of persons of similar rank), and grievance procedures. (JT)

  12. Reliability Generalization of the Psychopathy Checklist Applied in Youthful Samples

    ERIC Educational Resources Information Center

    Campbell, Justin S.; Pulos, Steven; Hogan, Mike; Murry, Francie

    2005-01-01

    This study examines the average reliability of Hare Psychopathy Checklists (PCLs) adapted for use in samples of youthful offenders (aged 12 to 21 years). Two forms of reliability are examined: 18 alpha estimates of internal consistency and 18 intraclass correlation (two or more raters) estimates of interrater reliability. The results, an average…

  13. Infants prefer to imitate a reliable person.

    PubMed

    Poulin-Dubois, Diane; Brooker, Ivy; Polonia, Alexandra

    2011-04-01

    Research has shown that preschoolers prefer to learn from individuals who are a reliable source of information. The current study examined whether the past reliability of a person's emotional signals influences infants' willingness to imitate that person. An emotional referencing task was first administered to infants in order to demonstrate the experimenter's credibility or lack thereof. Next, infants in both conditions watched as the same experimenter turned on a touch light using her forehead. Infants were then given the opportunity to reproduce this novel action. As expected, infants in the unreliable condition developed the expectation that the person's emotional cues were misleading. Thus, these infants were subsequently more likely to use their hands than their foreheads when attempting to turn on the light. In contrast, infants in the reliable group were more likely to imitate the experimenter's action using their foreheads. These results suggest that the reliability of the model influences infants' imitation.

  14. Reliability of chemical analyses of water samples

    SciTech Connect

    Beardon, R.

    1989-11-01

    Ground-water quality investigations require reliable chemical analyses of water samples. Unfortunately, laboratory analytical results are often unreliable. The Uranium Mill Tailings Remedial Action (UMTRA) Project`s solution to this problem was to establish a two phase quality assurance program for the analysis of water samples. In the first phase, eight laboratories analyzed three solutions of known composition. The analytical accuracy of each laboratory was ranked and three laboratories were awarded contracts. The second phase consists of on-going monitoring of the reliability of the selected laboratories. The following conclusions are based on two years experience with the UMTRA Project`s Quality Assurance Program. The reliability of laboratory analyses should not be taken for granted. Analytical reliability may be independent of the prices charged by laboratories. Quality assurance programs benefit both the customer and the laboratory.

  15. Achieving quality assurance through clinical audit.

    PubMed

    Patel, Seraphim

    2010-06-01

    Audit is a crucial component of improvements to the quality of patient care. Clinical audits are undertaken to help ensure that patients can be given safe, reliable and dignified care, and to encourage them to self-direct their recovery. Such audits are undertaken also to help reduce lengths of patient stay in hospital, readmission rates and delays in discharge. This article describes the stages of clinical audit and the support required to achieve organisational core values.

  16. Test-retest reliability of cognitive EEG

    NASA Technical Reports Server (NTRS)

    McEvoy, L. K.; Smith, M. E.; Gevins, A.

    2000-01-01

    OBJECTIVE: Task-related EEG is sensitive to changes in cognitive state produced by increased task difficulty and by transient impairment. If task-related EEG has high test-retest reliability, it could be used as part of a clinical test to assess changes in cognitive function. The aim of this study was to determine the reliability of the EEG recorded during the performance of a working memory (WM) task and a psychomotor vigilance task (PVT). METHODS: EEG was recorded while subjects rested quietly and while they performed the tasks. Within session (test-retest interval of approximately 1 h) and between session (test-retest interval of approximately 7 days) reliability was calculated for four EEG components: frontal midline theta at Fz, posterior theta at Pz, and slow and fast alpha at Pz. RESULTS: Task-related EEG was highly reliable within and between sessions (r0.9 for all components in WM task, and r0.8 for all components in the PVT). Resting EEG also showed high reliability, although the magnitude of the correlation was somewhat smaller than that of the task-related EEG (r0.7 for all 4 components). CONCLUSIONS: These results suggest that under appropriate conditions, task-related EEG has sufficient retest reliability for use in assessing clinical changes in cognitive status.

  17. Reliability of steam generator tubing

    SciTech Connect

    Kadokami, E.

    1997-02-01

    The author presents results on studies made of the reliability of steam generator (SG) tubing. The basis for this work is that in Japan the issue of defects in SG tubing is addressed by the approach that any detected defect should be repaired, either by plugging the tube or sleeving it. However, this leaves open the issue that there is a detection limit in practice, and what is the effect of nondetectable cracks on the performance of tubing. These studies were commissioned to look at the safety issues involved in degraded SG tubing. The program has looked at a number of different issues. First was an assessment of the penetration and opening behavior of tube flaws due to internal pressure in the tubing. They have studied: penetration behavior of the tube flaws; primary water leakage from through-wall flaws; opening behavior of through-wall flaws. In addition they have looked at the question of the reliability of tubing with flaws during normal plant operation. Also there have been studies done on the consequences of tube rupture accidents on the integrity of neighboring tubes.

  18. 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

  19. Comprehensive Design Reliability Activities for Aerospace Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Christenson, R. L.; Whitley, M. R.; Knight, K. C.

    2000-01-01

    This technical publication describes the methodology, model, software tool, input data, and analysis result that support aerospace design reliability studies. The focus of these activities is on propulsion systems mechanical design reliability. The goal of these activities is to support design from a reliability perspective. Paralleling performance analyses in schedule and method, this requires the proper use of metrics in a validated reliability model useful for design, sensitivity, and trade studies. Design reliability analysis in this view is one of several critical design functions. A design reliability method is detailed and two example analyses are provided-one qualitative and the other quantitative. The use of aerospace and commercial data sources for quantification is discussed and sources listed. A tool that was developed to support both types of analyses is presented. Finally, special topics discussed include the development of design criteria, issues of reliability quantification, quality control, and reliability verification.

  20. Investigation of reliability method formulations in Dakota/UQ.

    SciTech Connect

    Renaud, John E.; Perez, Victor M.; Wojtkiewicz, Steven F., Jr.; Agarwal, H.; Eldred, Michael Scott

    2004-07-01

    Reliability methods are probabilistic algorithms for quantifying the effect of simulation input uncertainties on response metrics of interest. In particular, they compute approximate response function distribution statistics (probability, reliability and response levels) based on specified input random variable probability distributions. In this paper, a number of algorithmic variations are explored for both the forward reliability analysis of computing probabilities for specified response levels (the reliability index approach (RIA)) and the inverse reliability analysis of computing response levels for specified probabilities (the performance measure approach (PMA)). These variations include limit state linearizations, probability integrations, warm starting and optimization algorithm selections. The resulting RIA/PMA reliability algorithms for uncertainty quantification are then employed within bi-level and sequential reliability-based design optimization approaches. Relative performance of these uncertainty quantification and reliability-based design optimization algorithms are presented for a number of computational experiments performed using the DAKOTA/UQ software.

  1. Reliable, Economic, Efficient CO2 Heat Pump Water Heater for North America

    SciTech Connect

    Radcliff, Thomas D; Sienel, Tobias; Huff, Hans-Joachim; Thompson, Adrian; Sadegh, Payman; Olsommer, Benoit; Park, Young

    2006-12-31

    Adoption of heat pump water heating technology for commercial hot water could save up to 0.4 quads of energy and 5 million metric tons of CO2 production annually in North America, but industry perception is that this technology does not offer adequate performance or reliability and comes at too high of a cost. Development and demonstration of a CO2 heat pump water heater is proposed to reduce these barriers to adoption. Three major themes are addressed: market analysis to understand barriers to adoption, use of advanced reliability models to design optimum qualification test plans, and field testing of two phases of water heater prototypes. Market experts claim that beyond good performance, market adoption requires 'drop and forget' system reliability and a six month payback of first costs. Performance, reliability and cost targets are determined and reliability models are developed to evaluate the minimum testing required to meet reliability targets. Three phase 1 prototypes are designed and installed in the field. Based on results from these trials a product specification is developed and a second phase of five field trial units are built and installed. These eight units accumulate 11 unit-years of service including 15,650 hours and 25,242 cycles of compressor operation. Performance targets can be met. An availability of 60% is achieved and the capability to achieve >90% is demonstrated, but overall reliability is below target, with an average of 3.6 failures/unit-year on the phase 2 demonstration. Most reliability issues are shown to be common to new HVAC products, giving high confidence in mature product reliability, but the need for further work to minimize leaks and ensure reliability of the electronic expansion valve is clear. First cost is projected to be above target, leading to an expectation of 8-24 month payback when substituted for an electric water heater. Despite not meeting all targets, arguments are made that an industry leader could sufficiently

  2. Aligning Items and Achievement Levels: A Study Comparing Expert Judgments

    ERIC Educational Resources Information Center

    Kaliski, Pamela; Huff, Kristen; Barry, Carol

    2011-01-01

    For educational achievement tests that employ multiple-choice (MC) items and aim to reliably classify students into performance categories, it is critical to design MC items that are capable of discriminating student performance according to the stated achievement levels. This is accomplished, in part, by clearly understanding how item design…

  3. Reliability-based pricing of electricity service

    SciTech Connect

    Hagazy, Y.A.

    1993-01-01

    This research has two objectives: (a) to develop a price structure that unbundles electricity service by reliability levels, and (b) to analyze the implications of such a structure on economic welfare, system operation, load management, and energy conservation. The authors developed a pricing mechanism for electricity service that combines priority (reliability differentiation) pricing with real-time Ramsey type pricing. The electric utility is assumed to be a single welfare-maximizing firm able to set and communicate prices instantly. At time of supply shortages, the utility has direct control over customer loads and follows a rationing method among customers willing to accept power interruptions. Therefore, customers are given the choice either to be served with a high reliability [open quotes]firm[close quotes] service, or to be subject to interruption. To encourage customers to make rational reliability choices, a payment/compensation mechanism was integrated into the welfare-maximization model. In order to account for uncertainties associated with the operation of electric power systems, a stochastic production cost simulation is also integrated with the model. The stochastic production cost simulation yields the estimation of the expected production, cost, marginal costs, and system reliability level at total demand. The authors examine the welfare gain and energy and reserve saving possibilities due to different pricing schemes. The results show that reliability-based pricing yields higher economic efficiency and energy and power saving than both spot and Ramsey pricing when system imperfect reliability is considered. Therefore, the implication of this research is that reliability-based pricing provides a feasible solution to electric utilities as a substitute for power purchases, and/or new capacity investment.

  4. Reliability evaluation methodology for NASA applications

    NASA Technical Reports Server (NTRS)

    Taneja, Vidya S.

    1992-01-01

    Liquid rocket engine technology has been characterized by the development of complex systems containing large number of subsystems, components, and parts. The trend to even larger and more complex system is continuing. The liquid rocket engineers have been focusing mainly on performance driven designs to increase payload delivery of a launch vehicle for a given mission. In otherwords, although the failure of a single inexpensive part or component may cause the failure of the system, reliability in general has not been considered as one of the system parameters like cost or performance. Up till now, quantification of reliability has not been a consideration during system design and development in the liquid rocket industry. Engineers and managers have long been aware of the fact that the reliability of the system increases during development, but no serious attempts have been made to quantify reliability. As a result, a method to quantify reliability during design and development is needed. This includes application of probabilistic models which utilize both engineering analysis and test data. Classical methods require the use of operating data for reliability demonstration. In contrast, the method described in this paper is based on similarity, analysis, and testing combined with Bayesian statistical analysis.

  5. Reliability improvement of distribution systems using SSVR.

    PubMed

    Hosseini, Mehdi; Shayanfar, Heidar Ali; Fotuhi-Firuzabad, Mahmoud

    2009-01-01

    This paper presents a reliability assessment algorithm for distribution systems using a Static Series Voltage Regulator (SSVR). Furthermore, this algorithm considers the effects of Distributed Generation (DG) units, alternative sources, system reconfiguration, load shedding and load adding on distribution system reliability indices. In this algorithm, load points are classified into 8 types and separated restoration times are considered for each class. Comparative studies are conducted to investigate the impacts of DG and alternative source unavailability on the distribution system reliability. For reliability assessment, the customer-oriented reliability indices such as SAIFI, SAIDI, CAIDI ASUI and also load- and energy-oriented indices such as ENS and AENS are evaluated. The effectiveness of the proposed algorithm is examined on the two standard distribution systems consisting of 33 and 69 nodes. The best location of the SSVR in distribution systems is determined based on different reliability indices, separately. Results show that the proposed algorithm is efficient for large-scale radial distribution systems and can accommodate the effects of fault isolation and load restoration.

  6. Student Achievement, 1986-87.

    ERIC Educational Resources Information Center

    Mangino, Evangelina

    This report summarizes results of student achievement in the Austin (Texas) Independent School District (AISD) on the Texas Educational Assessment of Minimum Skills (TEAMS) tests in 1986-87. Major findings indicate the following: (1) 99.4% of AISD seniors to graduate in May 1987 passed the Exit-Level TEAMS tests, with only 17 denied diplomas in…

  7. Grouping Students for Increased Achievements.

    ERIC Educational Resources Information Center

    Holloway, John H.

    2001-01-01

    Reviews results of four recent studies exploring the effects of various student-grouping schemes on academic achievement. Grouping plans included multiage classrooms, full-time ability grouping, and within-classroom grouping. Two studies investigated administrator attitudes toward student grouping. Several studies found that grouping plans…

  8. Reliability of Wireless Sensor Networks

    PubMed Central

    Dâmaso, Antônio; Rosa, Nelson; Maciel, Paulo

    2014-01-01

    Wireless Sensor Networks (WSNs) consist of hundreds or thousands of sensor nodes with limited processing, storage, and battery capabilities. There are several strategies to reduce the power consumption of WSN nodes (by increasing the network lifetime) and increase the reliability of the network (by improving the WSN Quality of Service). However, there is an inherent conflict between power consumption and reliability: an increase in reliability usually leads to an increase in power consumption. For example, routing algorithms can send the same packet though different paths (multipath strategy), which it is important for reliability, but they significantly increase the WSN power consumption. In this context, this paper proposes a model for evaluating the reliability of WSNs considering the battery level as a key factor. Moreover, this model is based on routing algorithms used by WSNs. In order to evaluate the proposed models, three scenarios were considered to show the impact of the power consumption on the reliability of WSNs. PMID:25157553

  9. Nuclear weapon reliability evaluation methodology

    SciTech Connect

    Wright, D.L.

    1993-06-01

    This document provides an overview of those activities that are normally performed by Sandia National Laboratories to provide nuclear weapon reliability evaluations for the Department of Energy. These reliability evaluations are first provided as a prediction of the attainable stockpile reliability of a proposed weapon design. Stockpile reliability assessments are provided for each weapon type as the weapon is fielded and are continuously updated throughout the weapon stockpile life. The reliability predictions and assessments depend heavily on data from both laboratory simulation and actual flight tests. An important part of the methodology are the opportunities for review that occur throughout the entire process that assure a consistent approach and appropriate use of the data for reliability evaluation purposes.

  10. Reliability of large superconducting magnets through design

    NASA Astrophysics Data System (ADS)

    Henning, C. D.

    1980-09-01

    As superconducting magnet systems grow larger and become the central component of major systems involving fusion, magnetohydrodynamics, and high energy physics, their reliability must be commensurate with the enormous capital investment in the project. Creative design is the most effective way of ensuring magnet reliability and providing a reasonable limit on the amount of quality control needed. By subjecting the last drawing operation in superconductor manufacture to a stress larger than the magnet design stress, a 100 percent proof test is achieved; cabled conductors offer mechanical redundancy, as do some methods of conductor joining; ground plane insulation should be multilayered to prevent arcs, and interturn and interlayer insulation spaced to be compatible with the self-extinguishing of arcs during quench voltages; electrical leads should be thermally protected; and guard vacuum spaces can be incorporated to control helium leaks.

  11. Reliable avionics design for deep space

    NASA Astrophysics Data System (ADS)

    Johnson, Stephen B.

    The technical and organizational problems posed by the Space Exploration Initiative (SEI) are discussed, and some possible solutions are examined. It is pointed out that SEI poses a whole new set of challenging problems in the design of reliable systems. These missions and their corresponding systems are far more complex than current systems. The initiative requires a set of vehicles and systems which must have very high levels of autonomy, reliability, and operability for long periods of time. It is emphasized that to achieve these goals in the face of great complexity, new technologies and organizational techniques will be necessary. It is noted that the key to a good design is good people. Not only must good people be found, but they must be placed in positions appropriate to their skills. It is argued that the atomistic and autocratic paradigm of vertical organizations must be replaced with more team-oriented and democratic structures.

  12. SALT and Spelling Achievement.

    ERIC Educational Resources Information Center

    Nelson, Joan

    A study investigated the effects of suggestopedic accelerative learning and teaching (SALT) on the spelling achievement, attitudes toward school, and memory skills of fourth-grade students. Subjects were 20 male and 28 female students from two self-contained classrooms at Kennedy Elementary School in Rexburg, Idaho. The control classroom and the…

  13. Iowa Women of Achievement.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This issue of the Goldfinch highlights some of Iowa's 20th century women of achievement. These women have devoted their lives to working for human rights, education, equality, and individual rights. They come from the worlds of politics, art, music, education, sports, business, entertainment, and social work. They represent Native Americans,…

  14. Schools Achieving Gender Equity.

    ERIC Educational Resources Information Center

    Revis, Emma

    This guide is designed to assist teachers presenting the Schools Achieving Gender Equity (SAGE) curriculum for vocational education students, which was developed to align gender equity concepts with the Kentucky Education Reform Act (KERA). Included in the guide are lesson plans for classes on the following topics: legal issues of gender equity,…

  15. Achieving Peace through Education.

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    While it is generally agreed that peace is desirable, there are barriers to achieving a peaceful world. These barriers are classified into three major areas: (1) an erroneous view of human nature; (2) injustice; and (3) fear of world unity. In a discussion of these barriers, it is noted that although the consciousness and conscience of the world…

  16. Explorations in achievement motivation

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1982-01-01

    Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

  17. Appraising Reading Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    To determine quality sequence in pupil progress, evaluation approaches need to be used which guide the teacher to assist learners to attain optimally. Teachers must use a variety of procedures to appraise student achievement in reading, because no one approach is adequate. Appraisal approaches might include: (1) observation and subsequent…

  18. Cognitive Processes and Achievement.

    ERIC Educational Resources Information Center

    Hunt, Dennis; Randhawa, Bikkar S.

    For a group of 165 fourth- and fifth-grade students, four achievement test scores were correlated with success on nine tests designed to measure three cognitive functions: sustained attention, successive processing, and simultaneous processing. This experiment was designed in accordance with Luria's model of the three functional units of the…

  19. Graders' Mathematics Achievement

    ERIC Educational Resources Information Center

    Bond, John B.; Ellis, Arthur K.

    2013-01-01

    The purpose of this experimental study was to investigate the effects of metacognitive reflective assessment instruction on student achievement in mathematics. The study compared the performance of 141 students who practiced reflective assessment strategies with students who did not. A posttest-only control group design was employed, and results…

  20. Achieving All Our Ambitions

    ERIC Educational Resources Information Center

    Hartley, Tricia

    2009-01-01

    National learning and skills policy aims both to build economic prosperity and to achieve social justice. Participation in higher education (HE) has the potential to contribute substantially to both aims. That is why the Campaign for Learning has supported the ambition to increase the proportion of the working-age population with a Level 4…

  1. Improving Educational Achievement.

    ERIC Educational Resources Information Center

    New York University Education Quarterly, 1979

    1979-01-01

    This is a slightly abridged version of the report of the National Academy of Education panel, convened at the request of HEW Secretary Joseph Califano and Assistant Secretary for Education Mary F. Berry, to study recent declines in student achievement and methods of educational improvement. (SJL)

  2. The Achievement Club

    ERIC Educational Resources Information Center

    Rogers, Ibram

    2009-01-01

    When Gabrielle Carpenter became a guidance counselor in Northern Virginia nine years ago, she focused on the academic achievement gap and furiously tried to close it. At first, she was compelled by tremendous professional interest. However, after seeing her son lose his zeal for school, Carpenter joined forces with other parents to form an…

  3. Achievement in Problem Solving

    ERIC Educational Resources Information Center

    Friebele, David

    2010-01-01

    This Action Research Project is meant to investigate the effects of incorporating research-based instructional strategies into instruction and their subsequent effect on student achievement in the area of problem-solving. The two specific strategies utilized are the integration of manipulatives and increased social interaction on a regular basis.…

  4. Advancing Student Achievement

    ERIC Educational Resources Information Center

    Walberg, Herbert J.

    2010-01-01

    For the last half century, higher spending and many modern reforms have failed to raise the achievement of students in the United States to the levels of other economically advanced countries. A possible explanation, says Herbert Walberg, is that much current education theory is ill informed about scientific psychology, often drawing on fads and…

  5. NCLB: Achievement Robin Hood?

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    2008-01-01

    In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the…

  6. Nuclear electric propulsion operational reliability and crew safety study: NEP systems/modeling report

    NASA Technical Reports Server (NTRS)

    Karns, James

    1993-01-01

    The objective of this study was to establish the initial quantitative reliability bounds for nuclear electric propulsion systems in a manned Mars mission required to ensure crew safety and mission success. Finding the reliability bounds involves balancing top-down (mission driven) requirements and bottom-up (technology driven) capabilities. In seeking this balance we hope to accomplish the following: (1) provide design insights into the achievability of the baseline design in terms of reliability requirements, given the existing technology base; (2) suggest alternative design approaches which might enhance reliability and crew safety; and (3) indicate what technology areas require significant research and development to achieve the reliability objectives.

  7. Effects of Mechanical Properties on the Circuit-Level Reliability of Cu/low-k Metallization

    SciTech Connect

    Thompson, C. V.

    2006-02-07

    The use of insulating over-layers and conducting refractory metal liners with Cu, along with the introduction of low-k materials with low stiffness, results in important differences in the mechanisms of electromigration-induced mechanical failure of Cu-based integrated circuit metallization compared to Al-based metallization. Despite this, the same electromigration test structures and circuit-level reliability assessment methodologies are often applied to Cu as those developed and used for Al. Unlike in Al technology, in Cu technology, measured electromigration lifetimes and critical line-length current-density products for immortality depend on whether test segments terminate in vias above or below the segments. Also, the critical stress for void nucleation is lower for Cu embedded in SiO2 than for Al embedded in SiO2. As a result, Cu must have a better test-level reliability to achieve the same circuit-level reliability as Al. The critical stress for void nucleation is expected to further decrease as lower-k, and therefore lower modulus, dielectrics and thinner liners are used. In addition, this evolution is expected to lead to lower stresses for Cu extrusion into the dielectric or rupture of the liner at the base of the vias. Lowered resistance to Cu extrusion will degrade reliability. Lower resistance to liner rupture is also likely to degrade reliability, though quantitative analysis of this effect requires further characterization of the lifetimes of multi-segment interconnect trees.

  8. Effects of Mechanical Properties on the Circuit-Level Reliability of Cu/low-k Metallization

    NASA Astrophysics Data System (ADS)

    Thompson, C. V.

    2006-02-01

    The use of insulating over-layers and conducting refractory metal liners with Cu, along with the introduction of low-k materials with low stiffness, results in important differences in the mechanisms of electromigration-induced mechanical failure of Cu-based integrated circuit metallization compared to Al-based metallization. Despite this, the same electromigration test structures and circuit-level reliability assessment methodologies are often applied to Cu as those developed and used for Al. Unlike in Al technology, in Cu technology, measured electromigration lifetimes and critical line-length current-density products for immortality depend on whether test segments terminate in vias above or below the segments. Also, the critical stress for void nucleation is lower for Cu embedded in SiO2 than for Al embedded in SiO2. As a result, Cu must have a better test-level reliability to achieve the same circuit-level reliability as Al. The critical stress for void nucleation is expected to further decrease as lower-k, and therefore lower modulus, dielectrics and thinner liners are used. In addition, this evolution is expected to lead to lower stresses for Cu extrusion into the dielectric or rupture of the liner at the base of the vias. Lowered resistance to Cu extrusion will degrade reliability. Lower resistance to liner rupture is also likely to degrade reliability, though quantitative analysis of this effect requires further characterization of the lifetimes of multi-segment interconnect trees.

  9. Confidence bounds on structural reliability

    NASA Technical Reports Server (NTRS)

    Mehta, S. R.; Cruse, T. A.; Mahadevan, S.

    1993-01-01

    Different approaches for quantifying physical, statistical, and model uncertainties associated with the distribution parameters which are aimed at determining structural reliability are described. Confidence intervals on the distribution parameters of the input random variables are estimated using four algorithms to evaluate uncertainty of the response. Design intervals are evaluated using either Monte Carlo simulation or an iterative approach. A first order approach can be used to compute a first approximation of the design interval, but its accuracy is not satisfactory. The regression approach which combines the iterative approach with Monte Carlo simulation is capable of providing good results if the performance function can be accurately represented using regression analysis. It is concluded that the design interval-based approach seems to be quite general and takes into account distribution and model uncertainties.

  10. A fourth generation reliability predictor

    NASA Technical Reports Server (NTRS)

    Bavuso, Salvatore J.; Martensen, Anna L.

    1988-01-01

    A reliability/availability predictor computer program has been developed and is currently being beta-tested by over 30 US companies. The computer program is called the Hybrid Automated Reliability Predictor (HARP). HARP was developed to fill an important gap in reliability assessment capabilities. This gap was manifested through the use of its third-generation cousin, the Computer-Aided Reliability Estimation (CARE III) program, over a six-year development period and an additional three-year period during which CARE III has been in the public domain. The accumulated experience of the over 30 establishments now using CARE III was used in the development of the HARP program.

  11. Challenged Schools, Remarkable Results: Three Lessons from California's Highest Achieving High Schools. A Report on Findings from Year Two of the California Best Practices Study Conducted by Springboard Schools

    ERIC Educational Resources Information Center

    Oberman, Ida

    2005-01-01

    In the year 1998, California began a massive experiment that focused on testing students and holding teachers and administrators accountable for results. The goal: dramatic, system-wide improvement. Schools' performance began to be measured using California's Academic Performance Index (API). In 2001, with passage of No Child Left Behind (NCLB),…

  12. The process group approach to reliable distributed computing

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.

    1992-01-01

    The difficulty of developing reliable distribution software is an impediment to applying distributed computing technology in many settings. Experience with the ISIS system suggests that a structured approach based on virtually synchronous process groups yields systems that are substantially easier to develop, exploit sophisticated forms of cooperative computation, and achieve high reliability. Six years of research on ISIS, describing the model, its implementation challenges, and the types of applications to which ISIS has been applied are reviewed.

  13. 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.

  14. Bitwise identical compiling setup: prospective for reproducibility and reliability of Earth system modeling

    NASA Astrophysics Data System (ADS)

    Li, R.; Liu, L.; Yang, G.; Zhang, C.; Wang, B.

    2016-02-01

    Reproducibility and reliability are fundamental principles of scientific research. A compiling setup that includes a specific compiler version and compiler flags is an essential technical support for Earth system modeling. With the fast development of computer software and hardware, a compiling setup has to be updated frequently, which challenges the reproducibility and reliability of Earth system modeling. The existing results of a simulation using an original compiling setup may be irreproducible by a newer compiling setup because trivial round-off errors introduced by the change in compiling setup can potentially trigger significant changes in simulation results. Regarding the reliability, a compiler with millions of lines of code may have bugs that are easily overlooked due to the uncertainties or unknowns in Earth system modeling. To address these challenges, this study shows that different compiling setups can achieve exactly the same (bitwise identical) results in Earth system modeling, and a set of bitwise identical compiling setups of a model can be used across different compiler versions and different compiler flags. As a result, the original results can be more easily reproduced; for example, the original results with an older compiler version can be reproduced exactly with a newer compiler version. Moreover, this study shows that new test cases can be generated based on the differences of bitwise identical compiling setups between different models, which can help detect software bugs in the codes of models and compilers and finally improve the reliability of Earth system modeling.

  15. Bitwise identical compiling setup: prospective for reproducibility and reliability of earth system modeling

    NASA Astrophysics Data System (ADS)

    Li, R.; Liu, L.; Yang, G.; Zhang, C.; Wang, B.

    2015-11-01

    Reproducibility and reliability are fundamental principles of scientific research. A compiling setup that includes a specific compiler version and compiler flags is essential technical supports for Earth system modeling. With the fast development of computer software and hardware, compiling setup has to be updated frequently, which challenges the reproducibility and reliability of Earth system modeling. The existing results of a simulation using an original compiling setup may be irreproducible by a newer compiling setup because trivial round-off errors introduced by the change of compiling setup can potentially trigger significant changes in simulation results. Regarding the reliability, a compiler with millions of lines of codes may have bugs that are easily overlooked due to the uncertainties or unknowns in Earth system modeling. To address these challenges, this study shows that different compiling setups can achieve exactly the same (bitwise identical) results in Earth system modeling, and a set of bitwise identical compiling setups of a model can be used across different compiler versions and different compiler flags. As a result, the original results can be more easily reproduced; for example, the original results with an older compiler version can be reproduced exactly with a newer compiler version. Moreover, this study shows that new test cases can be generated based on the differences of bitwise identical compiling setups between different models, which can help detect software bugs or risks in the codes of models and compilers and finally improve the reliability of Earth system modeling.

  16. Shunt capacitor effect on electrical distribution system reliability

    NASA Astrophysics Data System (ADS)

    Sallam, Abdelhay A.; Desouky, Mohamed; Desouky, Hussien

    1994-03-01

    To improve the security & reliability of a distribution system, as much power as feasible must go through a given transmission line. This can be achieved by using shunt capacitors as compensators. These shunt capacitive compensators improve the load carrying capability of the line by controlling the reactive power flow. Consequently, the capacitor existence can not be ignored in evaluating system reliability. The paper applies the state-space method to calculate the reliability indices for compensated & uncompensated systems with different success criteria. The importance of using shunt capacitors to improve the level of distribution system reliability is illustrated in addition to their original function as reactive power controllers. Our procedure, based on a Markov process, is applied to a numerical example, and indicates that system reliability is improved when using shunt capacitors.

  17. Maladaptive achievement patterns: a test of a diathesis-stress analysis of helplessness.

    PubMed

    Boggiano, A K

    1998-06-01

    The present study tested the assumptions, derived from a diathesis-stress model, that students' perceptions of autonomy-support in their classroom produce a relatively intrinsic as opposed to extrinsic motivational approach to academic tasks and that this approach, in turn, predicts qualitatively different responses to uncontrollable events. It was further assumed that students' motivational orientation would be more reliable than attributional style or perceptions of competence in predicting achievement patterns, including performance level after failure, use of adaptive attributions, and overall achievement scores. Results supported these predictions and further demonstrated, in longitudinal analyses, that motivational orientation may contribute to the formation of perceptions of competence and attributional style in students.

  18. Development and Reliability Evaluation of the Movement Rating Instrument for Virtual Reality Video Game Play

    PubMed Central

    Nawrotek, Joanna; Deschenes, Emilie; Giguere, Tia; Serafin, Julie; Bilodeau, Martin; Sveistrup, Heidi

    2016-01-01

    Background Virtual reality active video games are increasingly popular physical therapy interventions for children with cerebral palsy. However, physical therapists require educational resources to support decision making about game selection to match individual patient goals. Quantifying the movements elicited during virtual reality active video game play can inform individualized game selection in pediatric rehabilitation. Objective The objectives of this study were to develop and evaluate the feasibility and reliability of the Movement Rating Instrument for Virtual Reality Game Play (MRI-VRGP). Methods Item generation occurred through an iterative process of literature review and sample videotape viewing. The MRI-VRGP includes 25 items quantifying upper extremity, lower extremity, and total body movements. A total of 176 videotaped 90-second game play sessions involving 7 typically developing children and 4 children with cerebral palsy were rated by 3 raters trained in MRI-VRGP use. Children played 8 games on 2 virtual reality and active video game systems. Intraclass correlation coefficients (ICCs) determined intra-rater and interrater reliability. Results Excellent intrarater reliability was evidenced by ICCs of >0.75 for 17 of the 25 items across the 3 raters. Interrater reliability estimates were less precise. Excellent interrater reliability was achieved for far reach upper extremity movements (ICC=0.92 [for right and ICC=0.90 for left) and for squat (ICC=0.80) and jump items (ICC=0.99), with 9 items achieving ICCs of >0.70, 12 items achieving ICCs of between 0.40 and 0.70, and 4 items achieving poor reliability (close-reach upper extremity-ICC=0.14 for right and ICC=0.07 for left) and single-leg stance (ICC=0.55 for right and ICC=0.27 for left). Conclusions Poor video quality, differing item interpretations between raters, and difficulty quantifying the high-speed movements involved in game play affected reliability. With item definition clarification and

  19. Faculty achievement tracking tool.

    PubMed

    Pettus, Sarah; Reifschneider, Ellen; Burruss, Nancy

    2009-03-01

    Faculty development and scholarship is an expectation of nurse educators. Accrediting institutions, such as the Commission on Collegiate Nursing Education, the National League for Nursing Accrediting Commission, and the Higher Learning Commission, all have criteria regarding faculty achievement. A faculty achievement tracking tool (FATT) was developed to facilitate documentation of accreditation criteria attainment. Based on criteria from accrediting organizations, the roles that are addressed include scholarship, service, and practice. Definitions and benchmarks for the faculty as an aggregate are included. Undergoing reviews from different accrediting organizations, the FATT has been used once for accreditation of the undergraduate program and once for accreditation of the graduate program. The FATT is easy to use and has become an excellent adjunct for the preparation for accreditation reports. In addition, the FATT may be used for yearly evaluations, advancement, and merit.

  20. Project ACHIEVE final report

    SciTech Connect

    1997-06-13

    Project ACHIEVE was a math/science academic enhancement program aimed at first year high school Hispanic American students. Four high schools -- two in El Paso, Texas and two in Bakersfield, California -- participated in this Department of Energy-funded program during the spring and summer of 1996. Over 50 students, many of whom felt they were facing a nightmare future, were given the opportunity to work closely with personal computers and software, sophisticated calculators, and computer-based laboratories -- an experience which their regular academic curriculum did not provide. Math and science projects, exercises, and experiments were completed that emphasized independent and creative applications of scientific and mathematical theories to real world problems. The most important outcome was the exposure Project ACHIEVE provided to students concerning the college and technical-field career possibilities available to them.

  1. Electrical insulation design requirements and reliability goals

    NASA Astrophysics Data System (ADS)

    Ross, R. G., Jr.

    1983-11-01

    The solar cells in a photovoltaic module which must be electrically isolated from module exterior surfaces to satisfy a variety of safety and operating considerations are discussed. The performance and reliability of the insulation system are examined. Technical requirements involve the capability of withstanding the differential voltage from the solar cells to the module frame. The maximum system voltage includes consideration of maximum open circuit array voltages achieved under low-temperature, high-irradiance conditions, and transient overvoltages due to system feedback of lightning transients. The latter is bounded by the characteristics of incorporated voltage limiting devices such as MOVs.

  2. Reliability of large superconducting magnets through design

    NASA Astrophysics Data System (ADS)

    Henning, C. D.

    1981-01-01

    Design and quality control of large superconducting magnets for reliability comparable to pressure vessels are discussed. The failure modes are analyzed including thermoelectric instabilities, electrical shorts, cryogenic/vacuum defects, and mechanical malfunctions. Design must take into consideration conductor stability, insulation based on the Paschen curves, and the possible burnout of cryogenic transition leads if the He flow is interrupted. The final stage of the metal drawing process should stress the superconductor material to a stress value higher than the magnet design stress, cabled conductors should be used to achieve mechanical redundancy, and ground-plane insulation must be multilayered for arc prevention.

  3. A Vision for Spaceflight Reliability: NASA's Objectives Based Strategy

    NASA Technical Reports Server (NTRS)

    Groen, Frank; Evans, John; Hall, Tony

    2015-01-01

    In defining the direction for a new Reliability and Maintainability standard, OSMA has extracted the essential objectives that our programs need, to undertake a reliable mission. These objectives have been structured to lead mission planning through construction of an objective hierarchy, which defines the critical approaches for achieving high reliability and maintainability (R M). Creating a hierarchy, as a basis for assurance implementation, is a proven approach; yet, it holds the opportunity to enable new directions, as NASA moves forward in tackling the challenges of space exploration.

  4. [Efforts to achieve and effects of acquiring ISO 15189 in Tokushima University Hospital].

    PubMed

    Shono, Kazuko; Kishi, Misako; Satou, Mituyo; Nagamine, Yasunori; Doi, Tosio

    2009-12-01

    The medical laboratory of Tokushima University Hospital acquired ISO 15189, an international standard for medical laboratories, on July 6th, 2007, resulting in it achieving the 24th place in Japan and 5th place among national university hospitals. The first surveillance was just performed on October 6th, 2008. Tokushima University Hospital, in which our medical laboratory is included as one section, already succeeded in acquiring ISO 9001, PrivacyMark System, and Quality Health Care ver. 5 before accomplishing ISO 15189. To achieve ISO 15189, we prepared documents based on ISO 9001 without any consultation, resulting in a review of the difference between ISO 9001 and ISO 15189 after the preliminary survey. Although achieving ISO 15189 resulted in an improvement in the reliability of laboratory results and accuracy, leading to the development of our technical skills and awareness, and sharing of knowledge, we consider that the considerable investment of time to prepare the requirements remains to be overcome.

  5. The Reliability of Density Measurements.

    ERIC Educational Resources Information Center

    Crothers, Charles

    1978-01-01

    Data from a land-use study of small- and medium-sized towns in New Zealand are used to ascertain the relationship between official and effective density measures. It was found that the reliability of official measures of density is very low overall, although reliability increases with community size. (Author/RLV)

  6. Computer-Aided Reliability Estimation

    NASA Technical Reports Server (NTRS)

    Bavuso, S. J.; Stiffler, J. J.; Bryant, L. A.; Petersen, P. L.

    1986-01-01

    CARE III (Computer-Aided Reliability Estimation, Third Generation) helps estimate reliability of complex, redundant, fault-tolerant systems. Program specifically designed for evaluation of fault-tolerant avionics systems. However, CARE III general enough for use in evaluation of other systems as well.

  7. The Validity of Reliability Measures.

    ERIC Educational Resources Information Center

    Seddon, G. M.

    1988-01-01

    Demonstrates that some commonly used indices can be misleading in their quantification of reliability. The effects are most pronounced on gain or difference scores. Proposals are made to avoid sources of invalidity by using a procedure to assess reliability in terms of upper and lower limits for the true scores of each examinee. (Author/JDH)

  8. Reliability in CMOS IC processing

    NASA Technical Reports Server (NTRS)

    Shreeve, R.; Ferrier, S.; Hall, D.; Wang, J.

    1990-01-01

    Critical CMOS IC processing reliability monitors are defined in this paper. These monitors are divided into three categories: process qualifications, ongoing production workcell monitors, and ongoing reliability monitors. The key measures in each of these categories are identified and prioritized based on their importance.

  9. Essay Reliability: Form and Meaning.

    ERIC Educational Resources Information Center

    Shale, Doug

    This study is an attempt at a cohesive characterization of the concept of essay reliability. As such, it takes as a basic premise that previous and current practices in reporting reliability estimates for essay tests have certain shortcomings. The study provides an analysis of these shortcomings--partly to encourage a fuller understanding of the…

  10. Childhood vaccination: achievements and challenges.

    PubMed

    Ndumbe, P

    1996-09-01

    As the goal of eradicating smallpox was being met, the World Health Organization created its Expanded Programme on Immunisation (EPI) in 1974 and reached its initial goal of achieving full vaccination of 80% of the world's children by 1990. This effort was aided by the creation of "cold chain" delivery systems and resulted in the annual saving of 3.5 million children in less-developed countries. Current EPI vaccination goals include 1) eradication of poliomyelitis by the year 2000, 2) elimination of neonatal tetanus by the year 1995, 3) control of measles and hepatitis B, and 4) immunization of 90% of the world's children 1 year or younger by the year 2000. Goals of the Children's Vaccine Initiative (formed in 1991) include 1) provision of an adequate supply of affordable, safe, and effective vaccines; 2) production of improved and new vaccines; and 3) simplification of the logistics of vaccine delivery. Future challenges are to sustain high vaccination coverage, reach the unreached, achieve proper storage of vaccines and reduce waste, integrate new vaccines into national programs, and achieve vaccine self-sufficiency. The fact that these challenges will be difficult to achieve is illustrated by the situation in Africa where the high immunization levels achieved in 1990 have dropped dramatically. Those who must act to implement immunization programs are health personnel, families, governments, and development partners. In order to achieve equity in health, every child must be reached, governments must be made accountable for programs, health workers must convince families of the importance of vaccination, delivery systems must be in place to take advantage of the new vaccines being delivered, and a multisectoral approach must be taken to assure sustainability.

  11. Reliability-based design optimization using efficient global reliability analysis.

    SciTech Connect

    Bichon, Barron J.; Mahadevan, Sankaran; Eldred, Michael Scott

    2010-05-01

    Finding the optimal (lightest, least expensive, etc.) design for an engineered component that meets or exceeds a specified level of reliability is a problem of obvious interest across a wide spectrum of engineering fields. Various methods for this reliability-based design optimization problem have been proposed. Unfortunately, this problem is rarely solved in practice because, regardless of the method used, solving the problem is too expensive or the final solution is too inaccurate to ensure that the reliability constraint is actually satisfied. This is especially true for engineering applications involving expensive, implicit, and possibly nonlinear performance functions (such as large finite element models). The Efficient Global Reliability Analysis method was recently introduced to improve both the accuracy and efficiency of reliability analysis for this type of performance function. This paper explores how this new reliability analysis method can be used in a design optimization context to create a method of sufficient accuracy and efficiency to enable the use of reliability-based design optimization as a practical design tool.

  12. Photovoltaic performance and reliability workshop

    SciTech Connect

    Mrig, L.

    1993-12-01

    This workshop was the sixth in a series of workshops sponsored by NREL/DOE under the general subject of photovoltaic testing and reliability during the period 1986--1993. PV performance and PV reliability are at least as important as PV cost, if not more. In the US, PV manufacturers, DOE laboratories, electric utilities, and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in the field were brought together to exchange the technical knowledge and field experience as related to current information in this evolving field of PV reliability. The papers presented here reflect this effort since the last workshop held in September, 1992. The topics covered include: cell and module characterization, module and system testing, durability and reliability, system field experience, and standards and codes.

  13. 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.

  14. Bioharness™ Multivariable Monitoring Device: Part. II: Reliability

    PubMed Central

    Johnstone, James A.; Ford, Paul A.; Hughes, Gerwyn; Watson, Tim; Garrett, Andrew T.

    2012-01-01

    The Bioharness™ monitoring system may provide physiological information on human performance but the reliability of this data is fundamental for confidence in the equipment being used. The objective of this study was to assess the reliability of each of the 5 Bioharness™ variables using a treadmill based protocol. 10 healthy males participated. A between and within subject design to assess the reliability of Heart rate (HR), Breathing Frequency (BF), Accelerometry (ACC) and Infra-red skin temperature (ST) was completed via a repeated, discontinuous, incremental treadmill protocol. Posture (P) was assessed by a tilt table, moved through 160°. Between subject data reported low Coefficient of Variation (CV) and strong correlations(r) for ACC and P (CV< 7.6; r = 0.99, p < 0.01). In contrast, HR and BF (CV~19.4; r~0.70, p < 0.01) and ST (CV 3.7; r = 0.61, p < 0.01), present more variable data. Intra and inter device data presented strong relationships (r > 0.89, p < 0.01) and low CV (<10.1) for HR, ACC, P and ST. BF produced weaker relationships (r < 0.72) and higher CV (<17.4). In comparison to the other variables BF variable consistently presents less reliability. Global results suggest that the Bioharness™ is a reliable multivariable monitoring device during laboratory testing within the limits presented. Key pointsHeart rate and breathing frequency data increased in variance at higher velocities (i.e. ≥ 10 km.h-1)In comparison to the between subject testing, the intra and inter reliability presented good reliability in data suggesting placement or position of device relative to performer could be important for data collectionUnderstanding a devices variability in measurement is important before it can be used within an exercise testing or monitoring setting PMID:24149347

  15. A Robust and Reliability-Based Optimization Framework for Conceptual Aircraft Wing Design

    NASA Astrophysics Data System (ADS)

    Paiva, Ricardo Miguel

    A robustness and reliability based multidisciplinary analysis and optimization framework for aircraft design is presented. Robust design optimization and Reliability Based Design Optimization are merged into a unified formulation which streamlines the setup of optimization problems and aims at preventing foreseeable implementation issues in uncertainty based design. Surrogate models are evaluated to circumvent the intensive computations resulting from using direct evaluation in nondeterministic optimization. Three types of models are implemented in the framework: quadratic interpolation, regression Kriging and artificial neural networks. Regression Kriging presents the best compromise between performance and accuracy in deterministic wing design problems. The performance of the simultaneous implementation of robustness and reliability is evaluated using simple analytic problems and more complex wing design problems, revealing that performance benefits can still be achieved while satisfying probabilistic constraints rather than the simpler (and not as computationally intensive) robust constraints. The latter are proven to to be unable to follow a reliability constraint as uncertainty in the input variables increases. The computational effort of the reliability analysis is further reduced through the implementation of a coordinate change in the respective optimization sub-problem. The computational tool developed is a stand-alone application and it presents a user-friendly graphical user interface. The multidisciplinary analysis and design optimization tool includes modules for aerodynamics, structural, aeroelastic and cost analysis, that can be used either individually or coupled.

  16. A Report on Simulation-Driven Reliability and Failure Analysis of Large-Scale Storage Systems

    SciTech Connect

    Wan, Lipeng; Wang, Feiyi; Oral, H. Sarp; Vazhkudai, Sudharshan S.; Cao, Qing

    2014-11-01

    High-performance computing (HPC) storage systems provide data availability and reliability using various hardware and software fault tolerance techniques. Usually, reliability and availability are calculated at the subsystem or component level using limited metrics such as, mean time to failure (MTTF) or mean time to data loss (MTTDL). This often means settling on simple and disconnected failure models (such as exponential failure rate) to achieve tractable and close-formed solutions. However, such models have been shown to be insufficient in assessing end-to-end storage system reliability and availability. We propose a generic simulation framework aimed at analyzing the reliability and availability of storage systems at scale, and investigating what-if scenarios. The framework is designed for an end-to-end storage system, accommodating the various components and subsystems, their interconnections, failure patterns and propagation, and performs dependency analysis to capture a wide-range of failure cases. We evaluate the framework against a large-scale storage system that is in production and analyze its failure projections toward and beyond the end of lifecycle. We also examine the potential operational impact by studying how different types of components affect the overall system reliability and availability, and present the preliminary results

  17. Test-retest reliability of graph metrics of resting state MRI functional brain networks: A review.

    PubMed

    Andellini, Martina; Cannatà, Vittorio; Gazzellini, Simone; Bernardi, Bruno; Napolitano, Antonio

    2015-09-30

    The employment of graph theory to analyze spontaneous fluctuations in resting state BOLD fMRI data has become a dominant theme in brain imaging studies and neuroscience. Analysis of resting state functional brain networks based on graph theory has proven to be a powerful tool to quantitatively characterize functional architecture of the brain and it has provided a new platform to explore the overall structure of local and global functional connectivity in the brain. Due to its increased use and possible expansion to clinical use, it is essential that the reliability of such a technique is very strongly assessed. In this review, we explore the outcome of recent studies in network reliability which apply graph theory to analyze connectome resting state networks. Therefore, we investigate which preprocessing steps may affect reproducibility the most. In order to investigate network reliability, we compared the test-retest (TRT) reliability of functional data of published neuroimaging studies with different preprocessing steps. In particular we tested influence of global signal regression, correlation metric choice, binary versus weighted link definition, frequency band selection and length of time-series. Statistical analysis shows that only frequency band selection and length of time-series seem to affect TRT reliability. Our results highlight the importance of the choice of the preprocessing steps to achieve more reproducible measurements.

  18. Measuring Fidelity and Adaptation: Reliability of a Instrument for School-Based Prevention Programs.

    PubMed

    Bishop, Dana C; Pankratz, Melinda M; Hansen, William B; Albritton, Jordan; Albritton, Lauren; Strack, Joann

    2014-06-01

    There is a need to standardize methods for assessing fidelity and adaptation. Such standardization would allow program implementation to be examined in a manner that will be useful for understanding the moderating role of fidelity in dissemination research. This article describes a method for collecting data about fidelity of implementation for school-based prevention programs, including measures of adherence, quality of delivery, dosage, participant engagement, and adaptation. We report about the reliability of these methods when applied by four observers who coded video recordings of teachers delivering All Stars, a middle school drug prevention program. Interrater agreement for scaled items was assessed for an instrument designed to evaluate program fidelity. Results indicated sound interrater reliability for items assessing adherence, dosage, quality of teaching, teacher understanding of concepts, and program adaptations. The interrater reliability for items assessing potential program effectiveness, classroom management, achievement of activity objectives, and adaptation valences was improved by dichotomizing the response options for these items. The item that assessed student engagement demonstrated only modest interrater reliability and was not improved through dichotomization. Several coder pairs were discordant on items that overall demonstrated good interrater reliability. Proposed modifications to the coding manual and protocol are discussed.

  19. Software Reliability, Measurement, and Testing Software Reliability and Test Integration

    DTIC Science & Technology

    1992-04-01

    process rariables on software reliability A guidebook was produced to help pro- gram managers control and manage softwar~e reliability and testing...Integrated Reliability Management System "IRMS" 17 1.6 Organization of Report 17 2.0 SURVEYS 20 2.1 Software Projects Survey 20 2.1.1 Candidate Projects...Systems 103 4.2.2.3 Compiler 103 4.2.2.4 Data Management and Analysis 103 4.2.3 Test/Support Tools 103 4.2.3.1 DEC Test Manager 103 4.2.3.2 SDDL 103

  20. Learning reliable manipulation strategies without initial physical models

    NASA Technical Reports Server (NTRS)

    Christiansen, Alan D.; Mason, Matthew T.; Mitchell, Tom M.

    1990-01-01

    A description is given of a robot, possessing limited sensory and effectory capabilities but no initial model of the effects of its actions on the world, that acquires such a model through exploration, practice, and observation. By acquiring an increasingly correct model of its actions, it generates increasingly successful plans to achieve its goals. In an apparently nondeterministic world, achieving reliability requires the identification of reliable actions and a preference for using such actions. Furthermore, by selecting its training actions carefully, the robot can significantly improve its learning rate.

  1. Advancing medical device innovation through collaboration and coordination of structured data capture pilots: Report from the Medical Device Epidemiology Network (MDEpiNet) Specific, Measurable, Achievable, Results-Oriented, Time Bound (SMART) Think Tank.

    PubMed

    Reed, Terrie L; Drozda, Joseph P; Baskin, Kevin M; Tcheng, James; Conway, Karen; Wilson, Natalia; Marinac-Dabic, Danica; Heise, Theodore; Krucoff, Mitchell W

    2016-12-06

    The Medical Device Epidemiology Network (MDEpiNet) is a public private partnership (PPP) that provides a platform for collaboration on medical device evaluation and depth of expertise for supporting pilots to capture, exchange and use device information for improving device safety and protecting public health. The MDEpiNet SMART Think Tank, held in February, 2013, sought to engage expert stakeholders who were committed to improving the capture of device data, including Unique Device Identification (UDI), in key electronic health information. Prior to the Think Tank there was limited collaboration among stakeholders beyond a few single health care organizations engaged in electronic capture and exchange of device data. The Think Tank resulted in what has become two sustainable multi-stakeholder device data capture initiatives, BUILD and VANGUARD. These initiatives continue to mature within the MDEpiNet PPP structure and are well aligned with the goals outlined in recent FDA-initiated National Medical Device Planning Board and Medical Device Registry Task Force white papers as well as the vision for the National Evaluation System for health Technology.%.

  2. 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.

  3. Reliability assessment of power distribution systems using disjoint path-set algorithm

    NASA Astrophysics Data System (ADS)

    Bourezg, Abdrabbi; Meglouli, H.

    2015-10-01

    Finding the reliability expression of different substation configurations can help design a distribution system with the best overall reliability. This paper presents a computerized a nd implemented algorithm, based on Disjoint Sum of Product (DSOP) algorithm. The algorithm was synthesized and applied for the first time to the determination of reliability expression of a substation to determine reliability indices and costs of different substation arrangements. It deals with the implementation and synthesis of a new designed algorithm for DSOP implemented using C/C++, incorporating parallel problem solving capability and overcoming the disadvantage of Monte Carlo simulation which is the lengthy computational time to achieve satisfactory statistical convergence of reliability index values. The major highlight of this research being that the time consuming procedures of the DSOP solution generated for different substation arrangements using the proposed method is found to be significantly lower in comparison with the time consuming procedures of Monte Carlo-simulation solution or any other method used for the reliability evaluation of substations in the existing literature such as meta-heuristic and soft computing algorithms. This implementation gives the possibility of RBD simulation for different substation configurations in C/C++ using their path-set Boolean expressions mapped to probabilistic domain and result in simplest Sum of Disjoint Product which is on a one-to-one correspondence with reliability expression. This software tool is capable of handling and modeling a large, repairable system. Additionally, through its intuitive interface it can be easily used for industrial and commercial power systems. With simple Boolean expression for a configuration's RBD inputted, users can define a power system utilizing a RBD and, through a fast and efficient built-in simulation engine, the required reliability expressions and indices can be obtained. Two case studies

  4. MEASUREMENT: ACCOUNTING FOR RELIABILITY IN PERFORMANCE ESTIMATES.

    PubMed

    Waterman, Brian; Sutter, Robert; Burroughs, Thomas; Dunagan, W Claiborne

    2014-01-01

    When evaluating physician performance measures, physician leaders are faced with the quandary of determining whether departures from expected physician performance measurements represent a true signal or random error. This uncertainty impedes the physician leader's ability and confidence to take appropriate performance improvement actions based on physician performance measurements. Incorporating reliability adjustment into physician performance measurement is a valuable way of reducing the impact of random error in the measurements, such as those caused by small sample sizes. Consequently, the physician executive has more confidence that the results represent true performance and is positioned to make better physician performance improvement decisions. Applying reliability adjustment to physician-level performance data is relatively new. As others have noted previously, it's important to keep in mind that reliability adjustment adds significant complexity to the production, interpretation and utilization of results. Furthermore, the methods explored in this case study only scratch the surface of the range of available Bayesian methods that can be used for reliability adjustment; further study is needed to test and compare these methods in practice and to examine important extensions for handling specialty-specific concerns (e.g., average case volumes, which have been shown to be important in cardiac surgery outcomes). Moreover, it's important to note that the provider group average as a basis for shrinkage is one of several possible choices that could be employed in practice and deserves further exploration in future research. With these caveats, our results demonstrate that incorporating reliability adjustment into physician performance measurements is feasible and can notably reduce the incidence of "real" signals relative to what one would expect to see using more traditional approaches. A physician leader who is interested in catalyzing performance improvement

  5. Assessing achievement, affiliation, and power motives all at once: the Multi-Motive Grid (MMG).

    PubMed

    Sokolowski, K; Schmalt, H D; Langens, T A; Puca, R M

    2000-02-01

    In this article, we introduce the Multi-Motive Grid (MMG), a new diagnostic tool to measure motives with respect to their hope and fear components. The MMG combines features of the Thematic Apperception Test (TAT) with features of self-report questionnaires. Similar to the TAT, a set of 14 pictures representing a balanced set of achievement-arousing, affiliation-arousing, and power-arousing situations is presented together with a set of statements representing important motivational states. Six motive scores can be calculated: hope of success (HS) and fear of failure (FF) for the achievement motive, hope of affiliation (HA) and fear of rejection (FR) for the affiliation motive, and hope of power (HP) and fear of power (FP) for the power motive. Results of factor analyses suggest a 3-factor solution, with a general fear factor (FF, FR, FP), a factor combining the hope components of achievement and power (HS and HP), and a third factor representing HA, but the 6 a priori factors also reflect a sound structural model. Reliability data show that the internal consistency and retest reliability of the MMG scales satisfy traditional standards. External validity of the MMG has been established in all 3 motive domains. Three separate studies document that (a) individuals high in resultant achievement motivation perform better and report more flow experience, (b) individuals high in resultant power motivation profit more from a leadership training program, and (c) individuals high in resultant affiliation motivation recollect more highly memorable affiliative themes.

  6. Culture Representation in Human Reliability Analysis

    SciTech Connect

    David Gertman; Julie Marble; Steven Novack

    2006-12-01

    Understanding human-system response is critical to being able to plan and predict mission success in the modern battlespace. Commonly, human reliability analysis has been used to predict failures of human performance in complex, critical systems. However, most human reliability methods fail to take culture into account. This paper takes an easily understood state of the art human reliability analysis method and extends that method to account for the influence of culture, including acceptance of new technology, upon performance. The cultural parameters used to modify the human reliability analysis were determined from two standard industry approaches to cultural assessment: Hofstede’s (1991) cultural factors and Davis’ (1989) technology acceptance model (TAM). The result is called the Culture Adjustment Method (CAM). An example is presented that (1) reviews human reliability assessment with and without cultural attributes for a Supervisory Control and Data Acquisition (SCADA) system attack, (2) demonstrates how country specific information can be used to increase the realism of HRA modeling, and (3) discusses the differences in human error probability estimates arising from cultural differences.

  7. Continuous Reliability Enhancement for Wind (CREW) database :

    SciTech Connect

    Hines, Valerie Ann-Peters; Ogilvie, Alistair B.; Bond, Cody R.

    2013-09-01

    To benchmark the current U.S. wind turbine fleet reliability performance and identify the major contributors to component-level failures and other downtime events, the Department of Energy funded the development of the Continuous Reliability Enhancement for Wind (CREW) database by Sandia National Laboratories. This report is the third annual Wind Plant Reliability Benchmark, to publically report on CREW findings for the wind industry. The CREW database uses both high resolution Supervisory Control and Data Acquisition (SCADA) data from operating plants and Strategic Power Systems ORAPWindª (Operational Reliability Analysis Program for Wind) data, which consist of downtime and reserve event records and daily summaries of various time categories for each turbine. Together, these data are used as inputs into CREWs reliability modeling. The results presented here include: the primary CREW Benchmark statistics (operational availability, utilization, capacity factor, mean time between events, and mean downtime); time accounting from an availability perspective; time accounting in terms of the combination of wind speed and generation levels; power curve analysis; and top system and component contributors to unavailability.

  8. [Interrater reliability and agreement of the Swiss MDS version 2.0].

    PubMed

    Gattinger, Heidrun; Ott, Stefan; Saxer, Susi

    2014-02-01

    Numerous studies have been performed to assess the validity and reliability of the Minimum Data Set (MDS) of the Resident Assessment Instrument (RAI), which was developed and initially implemented in the United States. In general, RAI-MDS 2.0 has been reported to have moderate to high interrater reliability. From the late 1990s onwards the geriatric nursing assessment has been used in nursing homes in Switzerland. The objective of this study was to examine interrater agreement and reliability of the Swiss version of RAI-MDS 2.0 for the first time. For this purpose, 61 nursing home residents were independently assessed by two assessors. The MDS coordinator of the nursing home and an extern expert conducted independent resident assessments by reviewing the chart and asking front line staff about the residents' behaviour. Proportions of exact agreement were calculated and interrater reliability was assessed using kappa and intraclass correlation (ICC) coefficients. For most of the checked items, a high agreement between the two raters was observed. The reliability coefficients for 47 % of the items reached values between 0,81 and 1,0. 29 % of the items achieved values between 0,61 and 0,80. The values of 10 % of the items ranged between 0,41 and 0,60. Two items assessing skin condition obtained a value of 0,25 and 0, respectively. The results of the reliability analysis show that mainly items evaluating pain, mood and behavior, and some items estimating physical function and skin condition are less reliable.

  9. A reliable multicast for XTP

    NASA Technical Reports Server (NTRS)

    Dempsey, Bert J.; Weaver, Alfred C.

    1990-01-01

    Multicast services needed for current distributed applications on LAN's fall generally into one of three categories: datagram, semi-reliable, and reliable. Transport layer multicast datagrams represent unreliable service in which the transmitting context 'fires and forgets'. XTP executes these semantics when the MULTI and NOERR mode bits are both set. Distributing sensor data and other applications in which application-level error recovery strategies are appropriate benefit from the efficiency in multidestination delivery offered by datagram service. Semi-reliable service refers to multicasting in which the control algorithms of the transport layer--error, flow, and rate control--are used in transferring the multicast distribution to the set of receiving contexts, the multicast group. The multicast defined in XTP provides semi-reliable service. Since, under a semi-reliable service, joining a multicast group means listening on the group address and entails no coordination with other members, a semi-reliable facility can be used for communication between a client and a server group as well as true peer-to-peer group communication. Resource location in a LAN is an important application domain. The term 'semi-reliable' refers to the fact that group membership changes go undetected. No attempt is made to assess the current membership of the group at any time--before, during, or after--the data transfer.

  10. The reliability of DSM impact estimates

    SciTech Connect

    Vine, E.L.; Kushler, M.G.

    1995-05-01

    Demand-side management (DSM) critics continue to question the reliability of DSM program savings, and therefore, the need for funding such programs. In this paper, the authors examine the issues underlying the discussion of reliability of DSM program savings (e.g., bias and precision) and compare the levels of precision of DSM impact estimates for three utilities. Overall, the precision results from all three companies appear quite similar and, for the most part, demonstrate reasonably good precision levels around DSM savings estimate. The conclude by recommending activities for program managers and evaluators for increasing the understanding of the factors leading to DSM uncertainty and for reducing the level of DSM uncertainty.

  11. A Reliability-Based Track Fusion Algorithm

    PubMed Central

    Xu, Li; Pan, Liqiang; Jin, Shuilin; Liu, Haibo; Yin, Guisheng

    2015-01-01

    The common track fusion algorithms in multi-sensor systems have some defects, such as serious imbalances between accuracy and computational cost, the same treatment of all the sensor information regardless of their quality, high fusion errors at inflection points. To address these defects, a track fusion algorithm based on the reliability (TFR) is presented in multi-sensor and multi-target environments. To improve the information quality, outliers in the local tracks are eliminated at first. Then the reliability of local tracks is calculated, and the local tracks with high reliability are chosen for the state estimation fusion. In contrast to the existing methods, TFR reduces high fusion errors at the inflection points of system tracks, and obtains a high accuracy with less computational cost. Simulation results verify the effectiveness and the superiority of the algorithm in dense sensor environments. PMID:25950174

  12. Reliability Analysis of Uniaxially Ground Brittle Materials

    NASA Technical Reports Server (NTRS)

    Salem, Jonathan A.; Nemeth, Noel N.; Powers, Lynn M.; Choi, Sung R.

    1995-01-01

    The fast fracture strength distribution of uniaxially ground, alpha silicon carbide was investigated as a function of grinding angle relative to the principal stress direction in flexure. Both as-ground and ground/annealed surfaces were investigated. The resulting flexural strength distributions were used to verify reliability models and predict the strength distribution of larger plate specimens tested in biaxial flexure. Complete fractography was done on the specimens. Failures occurred from agglomerates, machining cracks, or hybrid flaws that consisted of a machining crack located at a processing agglomerate. Annealing eliminated failures due to machining damage. Reliability analyses were performed using two and three parameter Weibull and Batdorf methodologies. The Weibull size effect was demonstrated for machining flaws. Mixed mode reliability models reasonably predicted the strength distributions of uniaxial flexure and biaxial plate specimens.

  13. Reevaluating Interrater Reliability in Offender Risk Assessment

    ERIC Educational Resources Information Center

    van der Knaap, Leontien M.; Leenarts, Laura E. W.; Born, Marise Ph.; Oosterveld, Paul

    2012-01-01

    Offender risk and needs assessment, one of the pillars of the risk-need-responsivity model of offender rehabilitation, usually depends on raters assessing offender risk and needs. The few available studies of interrater reliability in offender risk assessment are, however, limited in the generalizability of their results. The present study…

  14. RELIABILITY OF SURROGATES FOR DETERMINING CRYPTOSPORIDIUM REMOVAL

    EPA Science Inventory

    Testing of field-scale bag filtration systems yielded results indicating that 4-6-um polystyrene microspheres can be used as a reliable surrogate for determining Cryptosporidium oocyst removal in bag filtration process. A nearly perfect linear correlation was observed between log...

  15. Structural Reliability and Monte Carlo Simulation.

    ERIC Educational Resources Information Center

    Laumakis, P. J.; Harlow, G.

    2002-01-01

    Analyzes a simple boom structure and assesses its reliability using elementary engineering mechanics. Demonstrates the power and utility of Monte-Carlo simulation by showing that such a simulation can be implemented more readily with results that compare favorably to the theoretical calculations. (Author/MM)

  16. (Centralized Reliability Data Organization (CRDO))

    SciTech Connect

    Haire, M J

    1987-04-21

    One of the primary goals of the Centralized Reliability Data Organization (CREDO) is to be an international focal point for the collection, analysis, and dissemination of liquid metal reactor (LMR) component reliability, availability, and maintainability (RAM) data. During FY-1985, the Department of Energy (DOE) entered into a Specific Memorandum of Agreement (SMA) with Japan's Power Reactor and Nuclear Fuel Development Corporation (PNC) regarding cooperative data exchange efforts. This agreement was CREDO's first step toward internationalization and represented an initial realization of the previously mentioned goal. DOE's interest in further internationalization of the CREDO system was the primary motivation for the traveler's attendance at the Reliability '87 conference.

  17. 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.

  18. Reliability assessment at airline inspection facilities. Volume 2: Protocol for an eddy current inspection reliability experiment

    NASA Astrophysics Data System (ADS)

    Spencer, Floyd; Borgonovi, Giancarlo; Roach, Dennis; Schurman, Don; Smith, Ron

    1993-05-01

    The Aging Aircraft NDI Development and Demonstration Center (AANC) at Sandia National Laboratories is charged by the FAA to support technology transfer, technology assessment, and technology validation. A key task facing the center is the establishment of a consistent and systematic methodology to assess the reliability of inspections through field experiments. This task is divided into three major areas: reliability of eddy current lap splice inspections at transport aircraft maintenance facilities; reliability of inspection at commuter aircraft maintenance facilities; and reliability of inspection associated with visual inspection of aircraft structural parts. Volume 2 is the second document in a series of three describing the planning, execution, and results of an eddy current inspection field experiment. This document provides a detailed description of the experimental hardware and protocols. It also describes the methodology to be used in the analysis of the data.

  19. Ion traps in nuclear physics-Recent results and achievements

    NASA Astrophysics Data System (ADS)

    Eronen, Tommi; Kankainen, Anu; Äystö, Juha

    2016-11-01

    Ion traps offer a way to determine nuclear binding energies through atomic mass measurements with a high accuracy and they are routinely used to provide isotopically or even isomerically pure beams of short-living ions for post-trap decay spectroscopy experiments. In this review, different ion-trapping techniques and progresses in recent nuclear physics experiments employing low-energy ion traps are discussed. The main focus in this review is on the benefit of recent high accuracy mass measurements to solve some key problems in physics related to nuclear structure, nuclear astrophysics as well as neutrinos. Also, several cases of decay spectroscopy experiments utilizing trap-purified ion samples are summarized.

  20. On Reporting Student Achievement: The Need for Meaningful Test Results

    ERIC Educational Resources Information Center

    Linden, Kathryn W.; Garrison, Wayne M.

    1977-01-01

    This paper provides users of teacher-made tests with a computer program designed to improve reporting of student performance on academic tasks. Test planning and construction and form and technique for reporting student performance are described. (CHK)