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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. 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.

  4. Poor Results for High Achievers

    ERIC Educational Resources Information Center

    Bui, Sa; Imberman, Scott; Craig, Steven

    2012-01-01

    Three million students in the United States are classified as gifted, yet little is known about the effectiveness of traditional gifted and talented (G&T) programs. In theory, G&T programs might help high-achieving students because they group them with other high achievers and typically offer specially trained teachers and a more advanced…

  5. Achieving Results in MBA Communication.

    ERIC Educational Resources Information Center

    Barrett, Deborah J.

    2002-01-01

    Describes how Rice University's Jones Graduate School of Management achieves their mission for the communication program. Discusses three keys to the success of the program: individual coaching, integrated team instruction, and constant assessment of the students and the program. Presents an overview of the program. (SG)

  6. 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…

  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. 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.

  11. Combining Grades from Different Assessments: How Reliable Is the Result?

    ERIC Educational Resources Information Center

    Cresswell, M. J.

    1988-01-01

    The author suggests combining grades from component assessments to provide an overall student assessment. He explores the concept of reliability and concludes that the overall assessment will be reliable only if the number of grades used to report component achievements equals or exceeds the number used to report overall achievement. (Author/CH)

  12. [Qinghai achieves good results in planned parenthood].

    PubMed

    1979-05-11

    After 8 days in session the Qinghai provincial meeting of representatives of advanced collectives and individuals in planned parenthood and maternal and child health work concluded in Xining on May 6. The meeting discussed and studied the population plan for our province and the specific policies and stipulations on planned parenthood, summed up and exchanged experiences and appraised and awarded 62 advanced collectives and 32 advanced individuals. Ma Wanli, vice chairman of the provincial revolutionary committee, and responsible comrades of the provincial culture and education office, public health units, trade union organizations, women's federations, commercial organizations, party schools, and other departments concerned were present at the closing ceremony. The advanced collectives and individuals were given awards at the ceremony and Comrade Ma Wanli spoke. Representatives attending the meeting said: Over the past several years, Qinghai's planned parenthood and maternal and child health work have been extensively developed in the cities and rural areas under the leadership of party committees at all levels. Great results have been achieved. The rate of Qinghai's population increase was reduced from 1971's 32.4/1000 persons to 1978's 19.4/1000 persons, hitting the target set by the state for our province. The natural rate of increase in some communes was reduced to less than 12/1000 persons.

  13. RTPP Analysis Results: Achievements and Challenges

    NASA Astrophysics Data System (ADS)

    Agrotis, Loukis; Alfaro Sanz, Pedro; Svehla, Drazen; Dow, John; Zandbergen, Rene

    2010-05-01

    One of the key objectives of the IGS Real Time Pilot Project is the establishment of an experimental IGS Real Time Clock Service comprising individual Analysis Centre (AC) solutions and the investigation of strategies for generating a Real Time combination product. The latter is intended to provide a stable, reliable and high quality GNSS product. Currently there are 4 ACs (BKG, DLR, ESA and NRCan) generating individual real time products, and a fifth (GMV) that is producing a product based on one-hour predictions. This paper will cover the evolution in the accuracies of the individual solutions and will show the impact that the participation in the RTPP has had on the ACs, serving not only as an external benchmark, but also as a discussion forum that has prompted their continued evolution and improvement. In its role as RTPP AC coordinator, ESOC has been computing and disseminating a daily combination clock product since July 2008, based on daily submissions of clock RINEX and SP3 orbit files by the individual ACs. This exercise has helped to develop and validate the combination techniques and the RTPP products are stored at the CDDIS, IGN and KASI data centres with the designation "igt". The current satellite clock quality, of better than 0.2 ns RMS compared to the IGS rapids, comfortably exceeds the initial RTPP goal of 0.5 ns and gives a high confidence on the implemented method. ESOC is currently working on the implementation of a Real Time combination product, from RTCM orbit and clock streams received in real time via BKG's NTRIP system. This service is expected to be ready in the March-April timeframe and be operational by mid 2010. As well as discussing the status and evolution of the Real Time products, this paper will also focus on specific problems and challenges in the Real Time processing. For example, it has been found that GPS Block IIA satellites exhibit occasional glitches, where most receivers loose lock simultaneously. These events cause clock

  14. 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…

  15. 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.

  16. 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…

  17. A strategy for achieving high reliability for reusable launch vehicles (RLVs)

    NASA Astrophysics Data System (ADS)

    Sholtis, Joseph A.

    2002-01-01

    Expendable launch vehicles (ELVs) have been used since the early 1960s to put numerous payloads, including humans, into space. Yet, in spite of their widespread use since that time, ELV reliability has not improved much. Why has this been the case? And, more importantly, what might be done to substantially improve the reliability of future reusable launch vehicles (RLVs) to levels needed for commercial viability, i.e., approaching that of the U.S. commercial airline industry? This paper attempts to answer these questions-by reviewing the history of launch vehicles, identifying factors important to their reliability and safety, and in doing so, offering a potential strategy for achieving high RLV reliability. The conclusion reached is that there is every reason to believe that high reliability (~0.99999 per mission) is achievable for future RLVs, if key features to enhance their inherent robustness, forgiveness, and recoverability are considered and integrated into RLV design and operation at the outset. It is hoped that this paper will serve as a catalyst for further discussions intended to ensure that high reliability is realized for RLVs. .

  18. Achieving reliable operation of a PSG-5000 delivery-water heater's tube system

    NASA Astrophysics Data System (ADS)

    Vasilenko, G. V.; Meshcheryakov, I. M.

    2010-01-01

    We analyze factors due to which damage occurred in the first period of operation in the 12Kh18N1 austenitic-steel tube system of the delivery-water heater used as part of a T-180/210-130 turbine unit operating in a couple with a high-pressure drum boiler. Technical solutions undertaken for achieving reliable operation of the heater are considered.

  19. 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

  20. Modeling of a bubble-memory organization with self-checking translators to achieve high reliability.

    NASA Technical Reports Server (NTRS)

    Bouricius, W. G.; Carter, W. C.; Hsieh, E. P.; Wadia, A. B.; Jessep, D. C., Jr.

    1973-01-01

    Study of the design and modeling of a highly reliable bubble-memory system that has the capabilities of: (1) correcting a single 16-adjacent bit-group error resulting from failures in a single basic storage module (BSM), and (2) detecting with a probability greater than 0.99 any double errors resulting from failures in BSM's. The results of the study justify the design philosophy adopted of employing memory data encoding and a translator to correct single group errors and detect double group errors to enhance the overall system reliability.

  1. Achieving a high-reliability organization through implementation of the ARCC model for systemwide sustainability of evidence-based practice.

    PubMed

    Melnyk, Bernadette Mazurek

    2012-01-01

    High-reliability health care organizations are those that provide care that is safe and one that minimizes errors while achieving exceptional performance in quality and safety. This article presents major concepts and characteristics of a patient safety culture and a high-reliability health care organization and explains how building a culture of evidence-based practice can assist organizations in achieving high reliability. The ARCC (Advancing Research and Clinical practice through close Collaboration) model for systemwide implementation and sustainability of evidence-based practice is highlighted as a key strategy in achieving high reliability in health care organizations.

  2. [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.

  3. 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

  4. 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…

  5. Alternate Forms Reliability of the Behavioral Relaxation Scale: Preliminary Results

    ERIC Educational Resources Information Center

    Lundervold, Duane A.; Dunlap, Angel L.

    2006-01-01

    Alternate forms reliability of the Behavioral Relaxation Scale (BRS; Poppen,1998), a direct observation measure of relaxed behavior, was examined. A single BRS score, based on long duration observation (5-minute), has been found to be a valid measure of relaxation and is correlated with self-report and some physiological measures. Recently,…

  6. 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.

  7. 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 elementary…

  8. 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 elementary…

  9. 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…

  10. Full-Day Kindergarten Results in Significant Achievement Gains

    ERIC Educational Resources Information Center

    Raskin, Candace F.; Haar, Jean M.

    2009-01-01

    In 2004, after an in-depth review of student achievement data for over 4,000 students, the administration of a school district in southern Minnesota identified the following challenges: (1) above-state-average number of special education students; (2) increasing number of English as Second Language (ESL) students; (3) increasing number of students…

  11. 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…

  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. PMID:27606585

  13. 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…

  14. 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…

  15. 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.

  16. Manufacturing of glassy thin shell for adaptive optics: results achieved

    NASA Astrophysics Data System (ADS)

    Poutriquet, F.; Rinchet, A.; Carel, J.-L.; Leplan, H.; Ruch, E.; Geyl, R.; Marque, G.

    2012-07-01

    Glassy thin shells are key components for the development of adaptive optics and are part of future & innovative projects such as ELT. However, manufacturing thin shells is a real challenge. Even though optical requirements for the front face - or optical face - are relaxed compared to conventional passive mirrors, requirements concerning thickness uniformity are difficult to achieve. In addition, process has to be completely re-defined as thin mirror generates new manufacturing issues. In particular, scratches and digs requirement is more difficult as this could weaken the shell, handling is also an important issue due to the fragility of the mirror. Sagem, through REOSC program, has recently manufactured different types of thin shells in the frame of European projects: E-ELT M4 prototypes and VLT Deformable Secondary Mirror (VLT DSM).

  17. The importance of thermal-vacuum testing in achieving high reliability of spacecraft mechanisms

    NASA Technical Reports Server (NTRS)

    Parker, K.

    1984-01-01

    The work performed on thermal vacuum testing of complex mechanisms is described. The objective of these tests is to assess the mechanism reliability by monitoring performance in an environment that closely resembles the environment that will occur during flight. To be both valid and cost effective, these tests are performed in a detailed, formally controlled manner. A review of the major test observations is given, during which time some failure modes are detected. Full confidence now exists in many mechanism and component designs, and much valuable data obtained.

  18. Achieving optimum post mine reclamation results through computer aided design

    SciTech Connect

    Johnson, M.; Irvin, R.; Metcalf, D.

    1997-12-31

    Recent technological advances have made it possible to map and model disturbed mine areas to plan the most cost effective manner in which to reclaim post mine land. The process not only can reduce the cost to reclaim each acre, but also enhances regulatory compliance. Results from a 21 acre test at Texas Utilities Mining Company`s Martin Lake-Oak Hill Mine have shown a significant reduction in dozer hours per acre to complete reclamation. A larger, more conclusive project has been completed at TUMCO`s Monticello-Winfield North Mine. The new project includes approximately 350 acres of the C-Area final pit. Results of this project have resulted in substantial cost savings versus conventional reclamation planning methods.

  19. 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…

  20. How to achieve an economic and reliable CP design using DnV RP B401

    SciTech Connect

    Thomason, W.H.; Rippon, I.; Foong, J.

    1995-11-01

    The 1993 Revision of Det Norske Veritas Industri Norge AS`s Recommended Practice RP B401 Cathodic Protection Design offers the operator the opportunity to use his own experience and data to justify more or less conservative designs. Examples of the use of this option to achieve an economic Southern North Sea CP design are presented. These examples include cost comparisons of actual bids received for CP/coating systems using different coating types. Some comparisons with NACE`s RP-0176-94 Corrosion. Control of Steel Fixed Offshore Platforms Associated with Petroleum Production are also made.

  1. Optimising contraction and alignment of cellular collagen hydrogels to achieve reliable and consistent engineered anisotropic tissue.

    PubMed

    O'Rourke, Caitriona; Drake, Rosemary A L; Cameron, Grant W W; Loughlin, A Jane; Phillips, James B

    2015-11-01

    Engineered anisotropic tissue constructs containing aligned cell and extracellular matrix structures are useful as in vitro models and for regenerative medicine. They are of particular interest for nervous system modelling and regeneration, where tracts of aligned neurons and glia are required. The self-alignment of cells and matrix due to tension within tethered collagen gels is a useful tool for generating anisotropic tissues, but requires an optimal balance between cell density, matrix concentration and time to be achieved for each specific cell type. The aim of this study was to develop an assay system based on contraction of free-floating cellular gels in 96-well plates that could be used to investigate cell-matrix interactions and to establish optimal parameters for subsequent self-alignment of cells in tethered gels. Using C6 glioma cells, the relationship between contraction and alignment was established, with 60-80% contraction in the 96-well plate assay corresponding to alignment throughout tethered gels made using the same parameters. The assay system was used to investigate the effect of C6 cell density, collagen concentration and time. It was also used to show that blocking α1 integrin reduced the contraction and self-alignment of these cells, whereas blocking α2 integrin had little effect. The approach was validated by using primary astrocytes in the assay system under culture conditions that modified their ability to contract collagen gels. This detailed investigation describes a robust assay for optimising cellular self-alignment and provides a useful reference framework for future development of self-aligned artificial tissue.

  2. 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,…

  3. 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.

  4. Improving Secondary Students' Academic Achievement through a Focus on Reform Reliability: 4- and 9-Year Findings from the High Reliability Schools Project

    ERIC Educational Resources Information Center

    Stringfield, Sam; Reynolds, David; Schaffer, Eugene C.

    2008-01-01

    The authors describe a reform effort in which characteristics derived from High Reliability Organization research were used to shape whole school reform. Longitudinal analyses of outcome data from 12 Welsh secondary schools indicated that 4 years after the effort was initiated, student outcomes at the sites were strongly positive. Additional…

  5. 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.

  6. 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.

  7. Interobserver reliability of rheumatologists performing musculoskeletal ultrasonography: results from a EULAR "Train the trainers" course

    PubMed Central

    Scheel, A; Schmidt, W; Hermann, K; Bruyn, G; D'Agostino, M; Grassi, W; Iagnocco, A; Koski, J; Machold, K; Naredo, E; Sattler, H; Swen, N; Szkudlarek, M; Wakefield, R; Ziswiler, H; Pasewaldt, D; Werner, C; Backhaus, M

    2005-01-01

    Objective: To evaluate the interobserver reliability among 14 experts in musculoskeletal ultrasonography (US) and to determine the overall agreement about the US results compared with magnetic resonance imaging (MRI), which served as the imaging "gold standard". Methods: The clinically dominant joint regions (shoulder, knee, ankle/toe, wrist/finger) of four patients with inflammatory rheumatic diseases were ultrasonographically examined by 14 experts. US results were compared with MRI. Overall agreements, sensitivities, specificities, and interobserver reliabilities were assessed. Results: Taking an agreement in US examination of 10 out of 14 experts into account, the overall κ for all examined joints was 0.76. Calculations for each joint region showed high κ values for the knee (1), moderate values for the shoulder (0.76) and hand/finger (0.59), and low agreement for ankle/toe joints (0.28). κ Values for bone lesions, bursitis, and tendon tears were high (κ = 1). Relatively good agreement for most US findings, compared with MRI, was found for the shoulder (overall agreement 81%, sensitivity 76%, specificity 89%) and knee joint (overall agreement 88%, sensitivity 91%, specificity 88%). Sensitivities were lower for wrist/finger (overall agreement 73%, sensitivity 66%, specificity 88%) and ankle/toe joints (overall agreement 82%, sensitivity 61%, specificity 92%). Conclusion: Interobserver reliabilities, sensitivities, and specificities in comparison with MRI were moderate to good. Further standardisation of US scanning techniques and definitions of different pathological US lesions are necessary to increase the interobserver agreement in musculoskeletal US. PMID:15640263

  8. Controlling decremental and inflationary effects in reliability estimation resulting from violations of assumptions.

    PubMed

    Becker, G

    2001-10-01

    Two assumptions in classical test theory, essential tau-equivalence and independence of measurement errors, when violated may produce attenuated or inflated estimates of reliability, respectively. Inflation stemming from correlated errors can be controlled by a procedure in which systematically created equivalent halves of a given measuring instrument are administered across two occasions. When poor approximations to equivalent halves are constructed for this purpose, however, distortion in the opposite direction may result, being sometimes quite large when measuring instruments are not essentially tau-equivalent (or, at the practical level, unidimensional). The nature of these decrements are discussed and illustrated, and a number of procedures for eliminating them introduced. PMID:11783569

  9. 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…

  10. Reliability of FEA on the Results of Mechanical Properties of Materials.

    PubMed

    Gomes, Erica Alves; Diana, Hugo Henrique; Oliveira, Juliana Santos; Silva-Sousa, Yara Teresinha Corrêa; Faria, Adriana Cláudia Lapria; Ribeiro, Ricardo Faria

    2015-01-01

    The present study evaluated the reliability of FEA on the results of different mechanical properties (E and v) of materials. Two 3D models of a maxillary canine with endodontic treatment, intracanal post, composite resin core and restored with porcelain-fused-to-metal crown were generated according to micro-CT images. Two groups with different E and ν values for porcelain, metal coping alloy, resin cement and composite resin were established. The materials' properties for group GL were based on literature data, while for group GIE the impulse excitation technique was used. A load of 180 N was applied at 45° on the incisal third of the lingual surface of the canine tooth. All models were supported by the periodontal ligament (x=y=z=0). The von Mises stress (VMS) was calculated. The stress values revealed differences between the groups for both VMS distribution and value. The porcelain (GL: 5.966 MPa; GIE: 7.478 MPa), metal coping (GL: 3.811 MPa; GIE: 0.973 MPa) and core (GL: 4.771 MPa; GIE: 0.026 MPa) were significantly affected. In conclusion, this study showed that the determination of mechanical properties (E and ν) of materials is essential for the reliability on the results of FEA. PMID:26963214

  11. Experimental results of fingerprint comparison validity and reliability: A review and critical analysis.

    PubMed

    Haber, Ralph Norman; Haber, Lyn

    2014-09-01

    Our purpose in this article is to determine whether the results of the published experiments on the accuracy and reliability of fingerprint comparison can be generalized to fingerprint laboratory casework, and/or to document the error rate of the Analysis-Comparison-Evaluation (ACE) method. We review the existing 13 published experiments on fingerprint comparison accuracy and reliability. These studies comprise the entire corpus of experimental research published on the accuracy of fingerprint comparisons since criminal courts first admitted forensic fingerprint evidence about 120years ago. We start with the two studies by Ulery, Hicklin, Buscaglia and Roberts (2011, 2012), because they are recent, large, designed specifically to provide estimates of the accuracy and reliability of fingerprint comparisons, and to respond to the criticisms cited in the National Academy of Sciences Report (2009). Following the two Ulery et al. studies, we review and evaluate the other eleven experiments, considering problems that are unique to each. We then evaluate the 13 experiments for the problems common to all or most of them, especially with respect to the generalizability of their results to laboratory casework. Overall, we conclude that the experimental designs employed deviated from casework procedures in critical ways that preclude generalization of the results to casework. The experiments asked examiner-subjects to carry out their comparisons using different responses from those employed in casework; the experiments presented the comparisons in formats that differed from casework; the experiments enlisted highly trained examiners as experimental subjects rather than subjects drawn randomly from among all fingerprint examiners; the experiments did not use fingerprint test items known to be comparable in type and especially in difficulty to those encountered in casework; and the experiments did not require examiners to use the ACE method, nor was that method defined

  12. Missing Data and Mixed Results: The Effects of Teach For America on Student Achievement Revisited

    ERIC Educational Resources Information Center

    Penner, Emily K.

    2013-01-01

    This paper revisits existing experimental work on Teach For America (TFA) and extends it by examining treatment effects across the distribution of student achievement. TFA is a rapidly expanding teacher preparation program that currently serves over half a million students in low-income districts across the country. Previous research results did…

  13. The Use of Achievement Test Results in Elementary School Guidance and Counseling.

    ERIC Educational Resources Information Center

    Perkins, Kyle; And Others

    Achievement test results, in combination with other data, are used to help guidance counselors plan students' future educational programs to the extent that such data assist school personnel in grouping students for optimal instructional benefits. Implementation of such plans may require fitting the curriculum to the student. Two types of schemata…

  14. [The reliability of reliability].

    PubMed

    Blancas Espejo, A

    1991-01-01

    The author critically analyzes an article by Rodolfo Corona Vazquez that questions the reliability of the preliminary results of the Eleventh Census of Population and Housing, conducted in Mexico in March 1990. The need to define what constitutes "reliability" for preliminary results is stressed. PMID:12317739

  15. Results of instrument reliability study for high-level nuclear-waste repositories. [Geotechnical parameters

    SciTech Connect

    Rogue, F.; Binnall, E.P.

    1982-10-01

    Reliable instrumentation will be needed to monitor the performance of future high-level waste repository sites. A study has been made to assess instrument reliability at Department of Energy (DOE) waste repository related experiments. Though the study covers a wide variety of instrumentation, this paper concentrates on experiences with geotechnical instrumentation in hostile repository-type environments. Manufacturers have made some changes to improve the reliability of instruments for repositories. This paper reviews the failure modes, rates, and mechanisms, along with manufacturer modifications and recommendations for additional improvements to enhance instrument performance. 4 tables.

  16. 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.

  17. 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.

  18. 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. PMID:24405937

  19. Estimating the Reliability of Single-Item Life Satisfaction Measures: Results from Four National Panel Studies

    ERIC Educational Resources Information Center

    Lucas, Richard E.; Donnellan, M. Brent

    2012-01-01

    Life satisfaction is often assessed using single-item measures. However, estimating the reliability of these measures can be difficult because internal consistency coefficients cannot be calculated. Existing approaches use longitudinal data to isolate occasion-specific variance from variance that is either completely stable or variance that…

  20. 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…

  1. 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…

  2. 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.

  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. 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.

  5. Assessment Results and Student Achievement; a Correlation Study Regarding Ability Grouping

    ERIC Educational Resources Information Center

    Slonaker, Richard V.

    2013-01-01

    School leaders face increased pressure to identify instructional and administrative practices that increase student achievement. However, achievement gaps persist between disadvantaged and non-disadvantaged student groups. This study highlighted relationships between ability grouping and academic achievement in a suburban school district.…

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

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

    PubMed

    Keogh, Louise A; Otlowski, Margaret F A

    2013-09-01

    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.

  13. 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

  14. 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,…

  15. Do Teacher Characteristics Matter? New Results on the Effects of Teacher Preparation on Student Achievement

    ERIC Educational Resources Information Center

    Kukla-Acevedo, Sharon

    2009-01-01

    Research fairly consistently demonstrates that teachers are an important measurable factor in student learning, yet few teacher characteristics are shown to be consistently related to student achievement. Using a state administrative dataset that matches individual students to their teachers over time, I find that math teachers' undergraduate…

  16. 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…

  17. 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.

  18. 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…

  19. Reliability and Levels of Difficulty of Objective Test Items in a Mathematics Achievement Test: A Study of Ten Senior Secondary Schools in Five Local Government Areas of Akure, Ondo State

    ERIC Educational Resources Information Center

    Adebule, S. O.

    2009-01-01

    This study examined the reliability and difficult indices of Multiple Choice (MC) and True or False (TF) types of objective test items in a Mathematics Achievement Test (MAT). The instruments used were two variants- 50-items Mathematics achievement test based on the multiple choice and true or false test formats. A total of five hundred (500)…

  20. Does simplifying transport and exposure yield reliable results? An analysis of four risk assessment methods.

    PubMed

    Zhang, Q; Crittenden, J C; Mihelcic, J R

    2001-03-15

    Four approaches for predicting the risk of chemicals to humans and fish under different scenarios were compared to investigate whether it is appropriate to simplify risk evaluations in situations where an individual is making environmentally conscious manufacturing decisions or interpreting toxics release inventory (TRI) data: (1) the relative risk method, that compares only a chemical's relative toxicity; (2) the toxicity persistence method, that considers a chemical's relative toxicity and persistence; (3) the partitioning, persistence toxicity method, that considers a chemical's equilibrium partitioning to air, land, water, and sediment, persistence in each medium, and its relative toxicity; and (4) the detailed chemical fate and toxicity method, that considers the chemical's relative toxicity, and realistic attenuation mechanisms such as advection, mass transfer and reaction in air, land, water, and sediment. In all four methods, the magnitude of the risk was estimated by comparing the risk of the chemical's release to that of a reference chemical. Three comparative scenarios were selected to evaluate the four approaches for making pollution prevention decisions: (1) evaluation of nine dry cleaning solvents, (2) evaluation of four reaction pathways to produce glycerine, and (3) comparison of risks for the chemical manufacturing and petroleum industry. In all three situations, it was concluded that ignoring or simplifying exposure calculations is not appropriate, except in cases where either the toxicity was very great or when comparing chemicals with similar fate. When the toxicity is low to moderate and comparable for chemicals, the chemicals' fate influences the results; therefore, we recommend using a detailed chemical fate and toxicity method because the fate of chemicals in the environment is assessed with consideration of more realistic attenuation mechanisms than the other three methods. In addition, our study shows that evaluating the risk associated

  1. 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.

  2. 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.}

  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. A reliable method for avoiding false negative results with Luminex single antigen beads; evidence of the prozone effect.

    PubMed

    Carey, B Sean; Boswijk, Kim; Mabrok, Mazen; Rowe, Peter A; Connor, Andrew; Saif, Imran; Poles, Anthony

    2016-07-01

    Luminex single antigen bead (SAB) assays have become an essential tool in monitoring the status of antibody to the Human Leucocyte Antigen (HLA) of patients both before and after transplantation. In addition SAB data is used to aid risk stratification to assess immunological risk of humoral rejection in solid organ transplantation (CTAG/BTAG guidelines) [1]. Increasingly laboratories are reporting false negative results at high antibody titre due to a prozone effect. Here we report a case study where the prozone effect led to a false negative antibody result that could have resulted in adverse outcome. We describe a method to reliably remove the prozone effect through heat inactivation and the addition of Ethylenediaminetetraacetic acid (EDTA) to the Luminex wash buffer. PMID:27109036

  5. 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…

  6. Relationship between Private Schooling and Achievement: Results from Rural and Urban India

    ERIC Educational Resources Information Center

    Chudgar, Amita; Quin, Elizabeth

    2012-01-01

    This paper contributes to the important but small body of research on the role of private schools in Indian education. It uses a household dataset from India with a rich set of household covariates and student performance data on reading, writing, and mathematics. For both rural and urban India the results from regression analyses indicate that…

  7. 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…

  8. 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,…

  9. "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.

  10. 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.

  11. Does achievement motivation mediate the semantic achievement priming effect?

    PubMed

    Engeser, Stefan; Baumann, Nicola

    2014-10-01

    The aim of our research was to understand the processes of the prime-to-behavior effects with semantic achievement primes. We extended existing models with a perspective from achievement motivation theory and additionally used achievement primes embedded in the running text of excerpts of school textbooks to simulate a more natural priming condition. Specifically, we proposed that achievement primes affect implicit achievement motivation and conducted pilot experiments and 3 main experiments to explore this proposition. We found no reliable positive effect of achievement primes on implicit achievement motivation. In light of these findings, we tested whether explicit (instead of implicit) achievement motivation is affected by achievement primes and found this to be the case. In the final experiment, we found support for the assumption that higher explicit achievement motivation implies that achievement priming affects the outcome expectations. The implications of the results are discussed, and we conclude that primes affect achievement behavior by heightening explicit achievement motivation and outcome expectancies. PMID:24820250

  12. The South America VLF Network - SAVNET: Achievements, Latest Results and Future Directions

    NASA Astrophysics Data System (ADS)

    Raulin, J.

    2013-05-01

    In this paper we present recent results obtained by the South America VLF Network (SAVNET). The use of the VLF technique by tracking subionospheric propagation anomalies appears as a very promising tool to study various aspects of Space Weather disturbances. On long timescales it is possible to indirectly monitor the solar Lyman-alpha radiation along the solar cycles. Short time phenomena like solar explosive events can be observed with 100% probability, even for the small intensity events. The effect of high-energy precipitating solar particles can be tracked in the low ionosphere. The same technique is also relevant to study the ionospheric perturbations caused by geomagnetic storms on typical timescales of a day to few days. Extra solar and terrestrial high-energy phenomena are naturally detected in the very sensitive low ionospheric plasma, as Gamma-ray bursts and Soft Gamma-ray repeaters. Finally, the remote sensing of the low ionosphere is also used to search for seismic-electromagnetic effects prior to Earthquakes. At the present time, SAVNET is composed of nine (9) tracking receiver stations in Brazil, Peru, Argentina and Mexico. In this presentation we will describe our future plans for expanding the array. Eastern Europe, Ecuador and Asia are good host candidates to participate in these forthcoming activities. The array expansion is necessary to improve the probability detection of very high-energy remote phenomena, and to demonstrate that these processes of great astrophysical importance can be easily detected using a cheap and simple technique.

  13. Safety Observations Achieve Results

    2000-01-16

    The SOAR web application provides a multi-checklist capability where focused observations can be created to address risk-likely work environments, tasks, etc. The SOAR web application has numerous reports to sort the data by key word, multiple factors (i.e., location, team, behavior, checklist, work environment, etc.), and the highest frequency of behaviors and error-likely predecessors, etc. Other performance indicators are also provided.

  14. 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…

  15. 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.

  16. 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…

  17. Direct disk diffusion test using European Clinical Antimicrobial Susceptibility Testing breakpoints provides reliable results compared with the standard method.

    PubMed

    Stokkou, Sofia; Geginat, Gernot; Schlüter, Dirk; Tammer, Ina

    2015-03-01

    Sepsis represents a life-threatening infection requiring the immediate start of antibacterial treatment to reduce morbidity. Thus, laboratories use direct antimicrobial susceptibility testing (AST) to rapidly generate preliminary results from positive blood cultures. As the direct AST has not yet been published to be evaluated with EUCAST breakpoints, the purpose of the study was to investigate the reliability of the direct agar diffusion test to correctly produce AST results from positive monobacterial blood cultures compared with the VITEK2-based definitive AST, when current EUCAST breakpoints were used. A total of 428 isolates from unselected monobacterial routine blood cultures and 110 challenge strains were included. Direct agar diffusion-based and standard VITEK2-based AST of 2803 bacterium-drug combinations yielded a total clinical category agreement of 95.47% with 1.28% very major errors and 3.42% combined major and minor errors. On the species level, very major errors were observed in the species-drug combinations Enterococcus spp.-high-level gentamicin (10.87%) and Staphylococcus spp.-rifampicin (5%), only. No very major errors occurred with Enterobacteriaceae and Pseudomonas aeruginosa. In most species-drug combinations, the direct agar diffusion test using EUCAST breakpoints precisely predicted the result of the definitive antibiotic susceptibility test and, thus, it can be used to optimize empiric antibiotic therapy until definitive results are available. PMID:25883798

  18. 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…

  19. An assessment of the reliability of palaeointensity results obtained from the Cretaceous aged Suhongtu section, Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    Hill, Mimi J.; Pan, Yongxin; Davies, Ceri J.

    2008-08-01

    looking at samples under the scanning electron microscope to suggest that maghaemite is present (albeit to varying degrees) in many of the samples. Alteration therefore occurred in nature and it is likely that the remanence will have been affected to differing degrees potentially causing underestimates in palaeointensity. Maghaemite is interpreted to be a remanence carrier where a component of remanence remains after heating to 580 °C and loss of pTRM acquisition capacity is found on heating. No correlation was found between the estimated palaeointensity (microwave or Thellier datasets) and amount of high temperature remanence or any rock magnetic parameter. This could suggest that the palaeointensity estimates are reliable or as seems likely more than one factor (such as methodology, protocol, interpretation, chemical remanent magnetisation (CRM) contamination and the geomagnetic field) are influencing the palaeointensity estimates. In an attempt to remove the influence of palaeointensity protocol and methodology the palaeointensity datasets were reduced to consist only of those results mutually consistent to 20% ( N = 22). No obvious correlation was again seen between the inferred maghaemite contribution and palaeointensity estimate. There is therefore no clear evidence for the biasing of results due to CRM contamination (assuming a simple relationship between biasing and maghaemite contribution) and it can thus be inferred that the geomagnetic field was a major influencing factor. Further studies are however needed to fully elucidate the extent and result of each possible influencing factor and ultimately the reliability of palaeointensity estimates from rocks of this type.

  20. 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).

  1. 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.

  2. 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.

  3. 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.

  4. 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…

  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. PMID:24128292

  6. 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.

  7. Trigone ventricular meningiomas: Is it possible to achieve good results even in the absence of high tech tools?

    PubMed Central

    Faquini, Igor; Fonseca, Ricardo Brandão; Vale de Melo, Sérgio Luís; Negri, Herika; Vieira, Eduardo; Saboia, Tammy; Azevedo-Filho, Hildo

    2015-01-01

    Background: Intraventricular meningiomas constitute 2% of intracranial meningiomas, representing a challenging disease for neurosurgeons; we report our experience through a case series, emphasizing surgical approaches and results. Methods: Between 2009 and 2012, four patients underwent microsurgical resection in our department. Clinical and imaging findings, surgical approaches, outcomes, and follow-up were analyzed. Results: Four patients (three females and one male) were included and the signs of intracranial hypertension were the main clinical presentation in all cases. The parietal approach through intraparietal sulcus was performed in 3 cases and parieto-occipital interhemispheric surgical route in 1 case. Gross total resection was achieved in all the patients without additional deficits and without the aid of neuronavigation, intraoperative monitoring, and intraoperative magnetic resonance imaging. Conclusion: Gross total resection is the gold standard treatment for such tumors and the intraparietal sulcus approach is an excellent choice for most of the cases. Careful anatomical knowledge contributes to a safer procedure even in the absence of high tech equipment assistance. PMID:26674002

  8. 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…

  9. Classroom Instruction and Science Achievement in Japan, Hong Kong, and Chinese Taipei: Results from the TIMSS 1999 Assessment

    ERIC Educational Resources Information Center

    House, J. Daniel

    2005-01-01

    The Third International Mathematics and Science Study represents the most comprehensive international assessment of educational contexts and student achievement yet conducted. As part of the examination of the effects of contextual factors on student achievement, a model was constructed that considered the effects of variables such as…

  10. 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.

  11. Preliminary Results of Bioactive Amniotic Suspension with Allograft for Achieving One and Two-Level Lumbar Interbody Fusion

    PubMed Central

    Kerr, Eubulus J.; Utter, Philip A.; Cavanaugh, David A.; Frank, Kelly A.; Moody, Devan; McManus, Brian; Stone, Marcus B.

    2016-01-01

    Background Bone graft material for lumbar fusion was historically autologous bone graft (ABG). In recent years alternatives such as allograft, demineralized bone matrix (DBM), ceramics, and bone morphogenetic protein (BMP) have gained favor, although the complications of these are not fully understood. Bioactive amniotic suspension (BAS) with allograft is a new class of material derived from human amniotic tissue. Methods Eligible patients receiving a one or two level lumbar interbody fusion with Nucel, a BAS with allograft, were contacted and scheduled for a mininmim 12 month follow-up visit. Patients were evaluated for fusion using CT's and plain radiographs. Clincal outcomes, including ODI, VAS back and leg were collected, as well as comorbidities including BMI, smoking status, diabetes and previous lumbar surgery. Results One-level patients (N=38) were 71.1% female with mean age of 58.4 ± 12.7 and mean BMI of 30.6 ± 6.08. Two-level patients (N=34) were 58.8% female with mean age of 49.3 ±10.9 and mean BMI of 30.1 ± 5.82. Kinematic fusion was achieved in 97.4% of one-level patients and 100% of two-level patients. Baseline comorbidities were present in 89.5% of one-level patients and 88.2% of two-level patients. No adverse events related to BAS were reported in this study. Conclusion Fusion status is evaluated with many different biologics and varying methods in the literature. BAS with allograft in this study demonstrated high fusion rates with no complications within a largely comorbid population. Although a small population, BAS with allograft results were encouraging for one and two-level lumbar interbody fusion in this study. Further prospective studies should be conducted to investigate safety and efficacy in a larger population. PMID:27162714

  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. 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.

  14. 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.

  15. 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.

  16. CENP-E is essential for reliable bioriented spindle attachment, but chromosome alignment can be achieved via redundant mechanisms in mammalian cells.

    PubMed

    McEwen, B F; Chan, G K; Zubrowski, B; Savoian, M S; Sauer, M T; Yen, T J

    2001-09-01

    CENP-E is a kinesin-like protein that when depleted from mammalian kinetochores leads to mitotic arrest with a mixture of aligned and unaligned chromosomes. In the present study, we used immunofluorescence, video, and electron microscopy to demonstrate that depletion of CENP-E from kinetochores via antibody microinjection reduces kinetochore microtubule binding by 23% at aligned chromosomes, and severely reduces microtubule binding at unaligned chromosomes. Disruption of CENP-E function also reduces tension across the centromere, increases the incidence of spindle pole fragmentation, and results in monooriented chromosomes approaching abnormally close to the spindle pole. Nevertheless, chromosomes show typical patterns of congression, fast poleward motion, and oscillatory motions. Furthermore, kinetochores of aligned and unaligned chromosomes exhibit normal patterns of checkpoint protein localization. These data are explained by a model in which redundant mechanisms enable kinetochore microtubule binding and checkpoint monitoring in the absence of CENP-E at kinetochores, but where reduced microtubule-binding efficiency, exacerbated by poor positioning at the spindle poles, results in chronically monooriented chromosomes and mitotic arrest. Chromosome position within the spindle appears to be a critical determinant of CENP-E function at kinetochores.

  17. 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…

  18. Improving the Academic Achievement of Third and Fourth Grade Underachievers as a Result of Improved Self-Esteem.

    ERIC Educational Resources Information Center

    Coakley, Barbara Fairfax

    This study was designed to improve the academic achievement of 35 third- and fourth-grade underachievers through improved self-esteem. Specific goals included focusing on self-concept and learning skills reinforcement, with the ultimate goal of increasing academic performance and motivation. Large group sessions with students focused on…

  19. 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…

  20. 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…

  1. 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

    2016-04-01

    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.

  2. 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.

  3. The Predictability of Enrolment and First-Year University Results from Secondary School Performance: The New Zealand National Certificate of Educational Achievement

    ERIC Educational Resources Information Center

    Shulruf, Boaz; Hattie, John; Tumen, Sarah

    2008-01-01

    This study investigates the predictive correlations between results from the New Zealand National Certificate of Educational Achievement (NCEA), a standards-based qualification, and university grade point averages achieved by first-year students in one large New Zealand University (and, for comparison purposes, also presents correlations from the…

  4. Is Marital Discord Taxonic and Can Taxonic Status Be Assessed Reliably? Results from a National, Representative Sample of Married Couples

    ERIC Educational Resources Information Center

    Whisman, Mark A.; Beach, Steven R. H.; Snyder, Douglas K.

    2008-01-01

    Addressing potential weaknesses in an earlier investigation, the authors examined the latent structure of marital discord using 4 product indicators from the Marital Satisfaction Inventory-Revised (Snyder, 1997) in a representative sample of community couples (N = 1,020). Results from 3 taxometric procedures suggested that marital discord is…

  5. 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.}

  6. 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.

  7. Retroperitoneal inoculation of murine neuroblastoma results in a reliable model for evaluation of the antitumor immune response.

    PubMed

    Katsanis, E; Blazar, B R; Bausero, M A; Gunther, R; Anderson, P M

    1994-04-01

    To more closely mimic the natural site of human neuroblastoma and the original spontaneous arising paraspinal murine tumor, the authors developed a new model system in which murine neuroblastoma cells (neuro-2a) are implanted directly into the retroperitoneal space. This method of administration resulted in an aggressive and reproducible neuroblastoma model, with death occurring at a median of 20.3 days after tumor implantation using 1 x 10(6) neuro-2a cells, compared with the intraperitoneal (median, 31 days) and subcutaneous routes (median, 35.1 days) (P < .001). Adoptive transfer of single cell suspensions from livers, spleens, and bone marrows of mice with retroperitoneal tumors into healthy hosts resulted in tumor growth, confirming the presence of metastatic foci in these organs. The retroperitoneal murine neuroblastoma model was used to assess the importance of natural killer (NK) and T cells in regulating the growth of neuro-2a in vivo. T cells played an equally protective role as NK cells; depletion of either T or NK populations significantly decreased survival as compared with undepleted mice. Elimination of both NK and T cells further accelerated mortality of neuro-2a-bearing mice as compared to those depleted of either T or NK populations. The retroperitoneal murine model is a highly relevant in vivo system for preclinical studies of new therapeutic approaches for neuroblastoma.

  8. Reliability and validity of a bilingual measure of religiosity in English and Vietnamese: preliminary results from a pilot study.

    PubMed

    Tran, Thanh V; Chan, Keith; Nguyen, Thuc-Nhi

    2011-06-01

    This study reports preliminary psychometric findings for a seven-item religiosity scale in a community-based sample of Vietnamese Americans ages 18 to 83 years (N = 119; 58% women, 42% men). A bilingual survey was distributed to Vietnamese who were evacuated during Hurricane Katrina and had returned after the disaster. Internal consistency, factorial structure validity, and criterion validity were evaluated on the scale items. The bilingual scale had good internal consistency. While exploratory and confirmatory factor analysis results provided support for a two-factor structure which captured Religious Involvement and Religious Coping, a one-factor model had slightly better fit. Individuals who scored high on the religiosity scale reported a significantly lower score on their stressful experiences during the hurricane, providing evidence of criterion validity.

  9. 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.

  10. 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. PMID:24812690

  11. Final results obtained in the treatment of bone cysts with methylprednisolone acetate (depo-medrol) and a discussion of results achieved in other bone lesions.

    PubMed

    Scaglietti, O; Marchetti, P G; Bartolozzi, P

    1982-05-01

    Extremely favorable results are obtained with the use of microcrystals of methylprednisolone acetate for treatment of bone cysts. These results have led to a complete suspension of surgical treatment of bone cysts since 1974. On the basis of these results with corticosteroids, a surgical procedure that involves an incision at the fracture location and bone graft inserted is not indicated. Results following surgery indicate a recurrence rate of approximately 25% to 30%. Since we are as yet unable to explain the mechanism by which the local injection of MPA promotes bone replacement of the cyst, the present observations only reaffirm the hypothesis (presented in our early publications) that the corticosteroid exerts a destructive action on the pathological tissue of the lesion, thus favoring a progressive process of repair. We consider this explanation valid even for lesions, e.g., eosinophilic granulomas and nonossifying fibromas, in which this method of treatment has had varying degrees of success. PMID:6804147

  12. 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 …

  13. Constructivist Teaching and Student Achievement: The Results of a School-Level Classroom Observation Study in Washington. Technical Report.

    ERIC Educational Resources Information Center

    Abbott, Martin L.; Fouts, Jeffrey T.

    This study built on a 2001-02 classroom observation study of Washington K-12 and technical schools that identified the extent of constructivist teaching activity. Results from classroom observations found that strong constructivist teaching was observable in 17 percent of the classroom lessons. The other 83 percent of the lessons observed may have…

  14. Predictive validity and reliability of the Turkish version of the risk assessment pressure sore scale in intensive care patients: results of a prospective study.

    PubMed

    Günes, Ülkü Yapucu; Efteli, Elçin

    2015-04-01

    Multiple pressure ulcer (PU) risk assessment instruments have been developed and tested, but there is no general consensus on which instrument to use for specific patient populations and care settings. The purpose of this study was to determine the reliability and predictive validity of the Turkish version of the Risk Assessment Pressure Sore (RAPS) instrument, which includes 12 variables--5 from the modified Norton Scale, 3 from the Braden Scale, and 3 from other research results--for use in intensive care unit (ICU) patients. The English version of the RAPS instrument was translated into Turkish and tested for internal consistency and predictive validity (sensitivity, specificity, positive predictive value, and negative predictive value) using a convenience sample of 122 patients consecutively admitted to an ICU unit in Turkey. The patients were assessed within 24 hours of admission, and after that, once a week until the development of a PU or discharge from the unit. The incidence of PUs in this population was 23%. The majority of ulcers that developed were Stage I. Internal consistency of the RAPS tool was adequate (Cronbach's α = 0.81). The best balance between sensitivity and specificity for ICU patients was reached at a cut-off point of ≤ 27 (ie, sensitivity = 74.2%, specificity = 31.8%, positive predictive value = 38.7%, and negative predictive value 91.3%). This is lower than the cut-off point reported in other studies of the RAPS scale. In this population of ICU patients, the RAPS scale was found to have acceptable reliability and poor validity. Additional studies to evaluate the predictive validity and reliability of the RAPS scale in other patient populations and care settings are needed.

  15. Silicon Photo Multipliers Characterization:. Recent Achievements and Latest Results. Investigation of SiPM for Photon Counting Applications

    NASA Astrophysics Data System (ADS)

    Chmill, V.; Caccia, M.; Cappellini, C.; Risigo, F.; Jastrzab, M.

    2008-06-01

    Within RAPSODI (European founded project - coop 32993) a novel type of Silicon Photo-Multiplier (SiPM) from different suppliers was investigated. The main parameters: dark count rate, amplification, dynamic range, quantum detection efficiency and optical cross talk have been studied for qualifying of the detectors. Results demonstrate the possibility to apply this detection technology for intense photon fluxes detection as well as for low plurality ones.

  16. 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.

  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. Social and Musical Objectives or Experiences School Music Teachers Anticipate Their Students Will Achieve as a Result of Attending a Summer Music Camp

    ERIC Educational Resources Information Center

    Richards, Eric W.

    2011-01-01

    The purpose of this study was to investigate specific social and musical objectives or experiences school music teachers anticipate their students will achieve as a result of attending a summer music camp. A survey instrument was developed to collect demographic data and responses to questions regarding 14 specific musical and social variables.…

  19. 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…

  20. 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…

  1. 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…

  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. Radiographic Progression of Patients With Psoriatic Arthritis Who Achieve Minimal Disease Activity in Response to Golimumab Therapy: Results Through 5 Years of a Randomized, Placebo‐Controlled Study

    PubMed Central

    van der Heijde, Désirée; Beutler, Anna; Gladman, Dafna; Mease, Philip; Krueger, Gerald G.; McInnes, Iain B.; Helliwell, Philip; Coates, Laura C.; Xu, Stephen

    2016-01-01

    Objective To evaluate long‐term outcomes in psoriatic arthritis (PsA) patients who achieved or did not achieve minimal disease activity (MDA) through 5 years of golimumab treatment in the GO‐REVEAL trial. Methods The GO‐REVEAL trial was a phase III, randomized, double‐blind trial with placebo‐control through week 24 followed by an open‐label extension of golimumab 50/100 mg treatment up to 5 years. In these post‐hoc analyses, MDA was defined by the presence of ≥5 of 7 PsA outcome measures (≤1 swollen joint, ≤1 tender joint, Psoriasis Area and Severity Index [PASI] ≤1, patient pain score ≤15, patient global disease activity score ≤20 [range 0–100], Health Assessment Questionnaire disability index [HAQ DI] ≤0.5, and ≤1 tender enthesis point). Results Treatment with golimumab yielded significantly higher MDA response rates versus patients randomized to placebo at week 14 (23.5% versus 1.0%; P < 0.0001), week 24 (28.1% versus 7.7%; P < 0.0001), and week 52 (42.4% versus 30.2%; P = 0.037). MDA was achieved at least once by ∼50% of golimumab‐treated patients overall. Irrespective of treatment randomization, achievement of MDA at ≥3 and ≥4 consecutive visits was associated with significantly less radiographic progression and more improvement in MDA components allowing specific assessment of physical function (HAQ DI) and overall disease activity (patient global assessment of disease activity) at week 256 versus patients not achieving MDA. Logistic regression analyses indicated that a 1‐unit higher baseline HAQ DI score yielded a significantly lower likelihood of achieving MDA at ≥3 (odds ratio 0.514 [95% confidence interval 0.321–0.824]; P = 0.006) and ≥4 (odds ratio 0.480 [95% confidence interval 0.290–0.795]; P = 0.004) consecutive visits. Conclusion Among golimumab‐treated PsA patients, better long‐term functional improvement, patient global assessment, and radiographic outcomes were observed when

  4. 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

  5. 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

  6. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  8. 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.

  9. 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.

  10. Reliability of tumor volume estimation from MR images in patients with malignant glioma. Results from the American College of Radiology Imaging Network (ACRIN) 6662 Trial.

    PubMed

    Ertl-Wagner, Birgit B; Blume, Jeffrey D; Peck, Donald; Udupa, Jayaram K; Herman, Benjamin; Levering, Anthony; Schmalfuss, Ilona M

    2009-03-01

    Reliable assessment of tumor growth in malignant glioma poses a common problem both clinically and when studying novel therapeutic agents. We aimed to evaluate two software-systems in their ability to estimate volume change of tumor and/or edema on magnetic resonance (MR) images of malignant gliomas. Twenty patients with malignant glioma were included from different sites. Serial post-operative MR images were assessed with two software systems representative of the two fundamental segmentation methods, single-image fuzzy analysis (3DVIEWNIX-TV) and multi-spectral-image analysis (Eigentool), and with a manual method by 16 independent readers (eight MR-certified technologists, four neuroradiology fellows, four neuroradiologists). Enhancing tumor volume and tumor volume plus edema were assessed independently by each reader. Intraclass correlation coefficients (ICCs), variance components, and prediction intervals were estimated. There were no significant differences in the average tumor volume change over time between the software systems (p > 0.05). Both software systems were much more reliable and yielded smaller prediction intervals than manual measurements. No significant differences were observed between the volume changes determined by fellows/neuroradiologists or technologists.Semi-automated software systems are reliable tools to serve as outcome parameters in clinical studies and the basis for therapeutic decision-making for malignant gliomas, whereas manual measurements are less reliable and should not be the basis for clinical or research outcome studies. PMID:18925402

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  12. Predictors and outcomes of sustained, intermittent or never achieving remission in patients with recent onset inflammatory polyarthritis: results from the Norfolk Arthritis Register

    PubMed Central

    Cook, Michael J.; Diffin, Janet; Scirè, Carlo A.; Lunt, Mark; MacGregor, Alex J.; Symmons, Deborah P. M.

    2016-01-01

    Objectives. Early remission is the current treatment strategy for patients with inflammatory polyarthritis (IP) and RA. Our objective was to identify baseline factors associated with achieving remission: sustained (SR), intermittent (IR) or never (NR) over a 5-year period in patients with early IP. Methods. Clinical and demographic data of patients with IP recruited to the Norfolk Arthritis Register (NOAR) were obtained at baseline and years 1, 2, 3 and 5. Remission was defined as no tender or swollen joints (out of 51). Patients were classified as NR or PR, respectively, if they were in remission at: no assessment or ⩾3 consecutive assessments after baseline, and IR otherwise. Ordinal regression and a random effects model, respectively, were used to examine the association between baseline factors, remission group and HAQ scores over time. Results. A total of 868 patients (66% female) were included. Of these, 54%, 34% and 12% achieved NR, IR and SR, respectively. In multivariate analysis, female sex (odds ratio, OR 0.47, 95% CI: 0.35, 0.63), higher tender joint count (OR = 0.94, 95% CI: 0.93, 0.96), higher HAQ (OR = 0.59, 95% CI: 0.48, 0.74), being obese (OR = 0.70, 95% CI: 0.50, 0.99), hypertensive (OR = 0.67, 95% CI: 0.50, 0.90) or depressed (OR = 0.74, 95% CI: 0.55, 1.00) at baseline were independent predictors of being in a lower remission group. IR and SR were associated with lower HAQ scores over time and lower DAS28 at year 5. Conclusion. Women with higher tender joint count and disability at baseline, depression, obesity and hypertension were less likely to achieve remission. This information could help when stratifying patients for more aggressive therapy. PMID:27220594

  13. 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…

  14. Reliability Prediction

    NASA Technical Reports Server (NTRS)

    1993-01-01

    RELAV, a NASA-developed computer program, enables Systems Control Technology, Inc. (SCT) to predict performance of aircraft subsystems. RELAV provides a system level evaluation of a technology. Systems, the mechanism of a landing gear for example, are first described as a set of components performing a specific function. RELAV analyzes the total system and the individual subsystem probabilities to predict success probability, and reliability. This information is then translated into operational support and maintenance requirements. SCT provides research and development services in support of government contracts.

  15. 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.

  16. 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

  17. 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.

  18. 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)

  19. 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…

  20. Quality Teaching in Addressing Student Achievement: A Comparative Study between National Board Certified Teachers and Other Teachers on the Kentucky Core Content Test Results

    ERIC Educational Resources Information Center

    Buecker, Harrie Lynne

    2010-01-01

    This dissertation focused on the link between quality teaching and its potential impact on student achievement. National Board Certification is used to represent quality teaching and student achievement is measured by the Kentucky Core Content Test. Data were gathered on the reading and mathematics scores of students of National Board Teachers who…

  1. 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…

  2. Defining Requirements for Improved Photovoltaic System Reliability

    SciTech Connect

    Maish, A.B.

    1998-12-21

    Reliable systems are an essential ingredient of any technology progressing toward commercial maturity and large-scale deployment. This paper defines reliability as meeting system fictional requirements, and then develops a framework to understand and quantify photovoltaic system reliability based on initial and ongoing costs and system value. The core elements necessary to achieve reliable PV systems are reviewed. These include appropriate system design, satisfactory component reliability, and proper installation and servicing. Reliability status, key issues, and present needs in system reliability are summarized for four application sectors.

  3. 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.

  4. Reliability systems for implantable cardiac defibrillator batteries

    NASA Astrophysics Data System (ADS)

    Takeuchi, Esther S.

    The reliability of the power sources used in implantable cardiac defibrillators is critical due to the life-saving nature of the device. Achieving a high reliability power source depends on several systems functioning together. Appropriate cell design is the first step in assuring a reliable product. Qualification of critical components and of the cells using those components is done prior to their designation as implantable grade. Product consistency is assured by control of manufacturing practices and verified by sampling plans using both accelerated and real-time testing. Results to date show that lithium/silver vanadium oxide cells used for implantable cardiac defibrillators have a calculated maximum random failure rate of 0.005% per test month.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Human reliability in petrochemical industry: an action research.

    PubMed

    Silva, João Alexandre Pinheiro; Camarotto, João Alberto

    2012-01-01

    This paper aims to identify conflicts and gaps between the operators' strategies and actions and the organizational managerial approach for human reliability. In order to achieve these goals, the research approach adopted encompasses literature review, mixing action research methodology and Ergonomic Workplace Analysis in field research. The result suggests that the studied company has a classical and mechanistic point of view focusing on error identification and building barriers through procedures, checklists and other prescription alternatives to improve performance in reliability area. However, it was evident the fundamental role of the worker as an agent of maintenance and construction of system reliability during the action research cycle.

  10. The reliability and validity of color indicators using digital image analysis of peristomal skin photographs: results of a preliminary prospective clinical study.

    PubMed

    Iizaka, Shinji; Asada, Mayumi; Koyanagi, Hiroe; Sasaki, Sanae; Naito, Ayumi; Konya, Chizuko; Sanada, Hiromi

    2014-03-01

    Accurate assessment is necessary to evaluate peristomal skin condition, but objective methods are lacking. The purpose of this prospective, repeated-measures study was to evaluate the reliability and validity of color indicators using digital image analysis of peristomal skin photographs. The 6-month study was conducted among 21 patients (mean age 65.1 years old, 15 men) with ostomies (14 colostomies, six ileostomies, and one urostomy) at four outpatient clinics. Photographs taken by nurses of the peristomal area using point-and-shoot cameras were processed using digital image analysis, which involved color calibration, image processing, and indicator calculation. An erythema index (EI), melanin index (MI), and hypopigmentation index were created to represent increased degrees of red, black, and white color, respectively, and their average values in the peristomal region of an image were calculated relative to values for intact skin. Reproducibility was evaluated using the interclass correlation coefficient (ICC). ICCs of color indicators for intact skin were >0.7 between baseline and the end of follow-up for the 16 participants with two or more clinic visits. Differences in these indices between peristomal and intact regions were evaluated using a linear mixed model. The EI and MI of peristomal skin were significantly higher than those of intact skin (n=42, P<0.001). All color indicators in adjacent regions and areas where adhesive was applied were associated with the discoloration severity score and visual analogue pain score (all P<0.05). This objective and simple method had adequate reproducibility and criterion-related validity and may be useful for peristomal skin assessment. Further research is warranted. PMID:24610557

  11. DMD reliability: a MEMS success story

    NASA Astrophysics Data System (ADS)

    Douglass, Michael

    2003-01-01

    The Digital Micromirror Device (DMD) developed by Texas Instruments (TI) has made tremendous progress in both performance and reliability since it was first invented in 1987. From the first working concept of a bistable mirror, the DMD is now providing high-brightness, high-contrast, and high-reliability in over 1,500,000 projectors using Digital Light Processing technology. In early 2000, TI introduced the first DMD chip with a smaller mirror (14-micron pitch versus 17-micron pitch). This allowed a greater number of high-resolution DMD chips per wafer, thus providing an increased output capacity as well as the flexibility to use existing package designs. By using existing package designs, subsequent DMDs cost less as well as met our customers' demand for faster time to market. In recent years, the DMD achieved the status of being a commercially successful MEMS device. It reached this status by the efforts of hundreds of individuals working toward a common goal over many years. Neither textbooks nor design guidelines existed at the time. There was little infrastructure in place to support such a large endeavor. The knowledge we gained through our characterization and testing was all we had available to us through the first few years of development. Reliability was only a goal in 1992 when production development activity started; a goal that many throughout the industry and even within Texas Instruments doubted the DMD could achieve. The results presented in this paper demonstrate that we succeeded by exceeding the reliability goals.

  12. 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.

  13. [Interrater reliability of the Braden scale].

    PubMed

    Kottner, Jan; Tannen, Antje; Dassen, Theo

    2008-04-01

    Pressure ulcer risk assessment scales can assist nurses in determining the individual pressure ulcer risk. Although the Braden scale is widely used throughout Germany, its psychometric properties are yet unknown. The aim of the study was to determine the interrater reliability of the Braden scale and to compare the results with those of published data. A literature review was conducted. 20 studies measuring the interrater reliability of the Braden scale were evaluated. Only three of those studies investigated the interrater reliability of single items. The Pearson product-moment correlation coefficient (0.80 to 1.00) was calculated in most studies for an evaluation of the Braden scale as a whole. However, the use of correlation coefficients is inappropriate for measuring the interrater reliability of the Braden scale. Measures of the intraclass correlation coefficient varied from 0.83 to 0.99. The investigation of the interrater reliability of the Braden scale's German version was conducted in a German nursing home in 2006. Nurses independently rated 18 and 32 residents twice. Nurses achieved the highest agreement when rating the items "friction and shear" and "activity" (overall proportion of agreement = 0.67 to 0.84, Cohen's Kappa = 0.57 to 0.73). The lowest agreement was achieved when the item "nutrition" (overall proportion of agreement = 0.47 to 0.51, Cohen's Kappa = 0.28 to 0.30) was rated. For 66% of the rated residents the difference in the obtained Braden scores was equal or less than one point. Intraclass correlation coefficients were 0.91 (95% confidence interval 0.82 to 0.96) and 0.88 (95% confidence interval 0.61 to 0.96). This indicates that the interrater reliability of the Braden scale was high in the examined setting.

  14. Beating the Odds: A City-by-City Analysis of Student Performance and Achievement Gaps on State Assessments. Results from the 2003-2004 School Year

    ERIC Educational Resources Information Center

    Casserly, Michael

    2005-01-01

    The Council of the Great City Schools has prepared this fifth edition of "Beating the Odds" ("Beating the Odds V)" to give the nation another look at how inner-city schools are performing on the academic goals and standards set by the states for our children. This analysis examines student achievement in math and reading through spring 2004. It…

  15. 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…

  16. 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,…

  17. The Effects of a Sustained, Job-Embedded Professional Development on Elementary Teachers' Math Teaching Self-Efficacy and the Resulting Effects on Their Students' Achievement

    ERIC Educational Resources Information Center

    Althauser, Krista Louise

    2010-01-01

    This study investigated the impact of a district-wide mathematics professional development program on elementary teachers' general and personal efficacy. It also explored connections among teacher efficacy and socioeconomic status with student achievement. Using a quantitative approach, a job-embedded professional development initiative…

  18. The reliability analysis of Xpert-positive result for smear-negative and culture-negative specimen collected from bone and joint tuberculosis suspects

    PubMed Central

    Wei, Guomei; Mu, Jing; Wang, Guirong; Huo, Fengmin; Dong, Lingling; Li, Yunxu

    2016-01-01

    Background The Xpert MTB/RIF assay (Xpert; Cepheid, Sunnyvale, CA, USA) has been widely used for pulmonary and extra-pulmonary tuberculosis (TB) diagnosis. In clinical practice, specimen yielding smear-negative, culture-negative but Xpert-positive results is frequently confronted. Due to the notorious possibility of contamination that molecular tests always been thought of, Xpert-positive results without bacteriological supporting evidence arouse great confusions to clinicians. Methods A retrospective study was performed. From April 2014 to February 2015, 852 clinical specimens were Xpert-positive. The results of Xpert assay, bacteriological and pathological examinations from either the same specimens or from the specimens collected during same clinical operations were investigated. Results A total of 90 specimens with Xpert-positive but smear-negative and culture-negative results were recruited, and 81 of them were pus specimens collected from Bone and Joint Tuberculosis (BJTB) patients. According to the pathological examination results, 77 of the 81 pus specimens, 8 of 9 other types of specimens were confirmed as either TB or strongly suggestive of TB; three pus specimens and one biopsy tissue were also suggested TB but with less stronger evidence; only one pus specimen was not TB suggestive. Conclusions Our study demonstrated that Xpert could be trusted for BJTB diagnosis even when no supporting bacteriological evidence is available in high TB prevalence settings. Our results will alleviate the confusion among clinicians in such scenarios. PMID:27293838

  19. 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.

  20. Reliability design and assessment of a micro-probe using the results of a tensile test of a beryllium-copper alloy thin film

    NASA Astrophysics Data System (ADS)

    Park, Jun-Hyub; Shin, Myung-Soo

    2011-09-01

    This paper describes the results of tensile tests for a beryllium-copper (BeCu) alloy thin film and the application of the results to the design of a probe. The copper alloy films were fabricated by electroplating. To obtain the tensile characteristics of the film, the dog-bone type specimen was fabricated by the etching method. The tensile tests were performed with the specimen using a test machine developed by the authors. The BeCu alloy has an elastic modulus of 119 GPa and the 0.2% offset yield and ultimate tensile strengths of 1078 MPa and 1108 MPa, respectively. The design and manufacture of a smaller probe require higher pad density and smaller pad-pitch chips. It should be effective in high-frequency testing. For the design of a new micro-probe, we investigated several design parameters that may cause problems, such as the contact force and life, using the tensile properties and the design of experiment method in conjunction with finite element analysis. The optimal dimensions of the probe were found using the response surface method. The probe with optimal dimensions was manufactured by a precision press process. It was verified that the manufactured probe satisfied the life, the contact force and the over drive through the compression tests and the life tests of the probes.

  1. 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.

  2. 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.

  3. 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.

  4. Results of vortex-suppressor tests, single-outlet sump tests and miscellaneous sensitivity tests. Containment sump reliability studies generic task A-43. [PWR; BWR

    SciTech Connect

    Padmanabhan, M.

    1982-09-01

    Full scale tests of flow conditions in Containment Recirculation Sumps for nuclear power stations were conducted at the Alden Research Laboratory (ARL) of Worcester Polytechnic Institute (WPI) to provide sump hydraulic design and performance data for use in resolving the Unresolved Safety Issue, A-43, Containment Sump Performance. This document is a report of the results of investigations conducted as a part of Phase II of the test program, including: (a) vortex suppressor tests to study in detail the hydraulic behavior of two commonly used suppressors; namely, cubic cage and horizontal floor grating; (b) single outlet sump tests to ascertain the hydraulic performance of single outlet sumps compared to double outlet sumps; and (c) tests to study the effects on the hydraulic performance of a solid partition wall in a double outlet sump, pump overspeed (i.e., higher flow), outlet pipe diameter, and bellmouth entrances.

  5. 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.

  6. 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.

  7. 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

  8. 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…

  9. Some Reliability Estimates for Computerized Adaptive Tests.

    ERIC Educational Resources Information Center

    Nicewander, W. Alan; Thomasson, Gary L.

    1999-01-01

    Derives three reliability estimates for the Bayes modal estimate (BME) and the maximum-likelihood estimate (MLE) of theta in computerized adaptive tests (CATs). Computes the three reliability estimates and the true reliabilities of both BME and MLE for seven simulated CATs. Results show the true reliabilities for BME and MLE to be nearly identical…

  10. Simvastatin Hydroxy Acid Fails to Attain Sufficient Central Nervous System Tumor Exposure to Achieve a Cytotoxic Effect: Results of a Preclinical Cerebral Microdialysis Study.

    PubMed

    Patel, Yogesh T; Jacus, Megan O; Davis, Abigail D; Boulos, Nidal; Turner, David C; Vuppala, Pradeep K; Freeman, Burgess B; Gilbertson, Richard J; Stewart, Clinton F

    2016-04-01

    3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors were potent hits against a mouse ependymoma cell line, but their effectiveness against central nervous system tumors will depend on their ability to cross the blood-brain barrier and attain a sufficient exposure at the tumor. Among 3-hydroxy-3-methylglutaryl coenzyme A inhibitors that had activity in vitro, we prioritized simvastatin (SV) as the lead compound for preclinical pharmacokinetic studies based on its potential for central nervous system penetration as determined from in silico models. Furthermore, we performed systemic plasma disposition and cerebral microdialysis studies of SV (100 mg/kg, p.o.) in a murine model of ependymoma to characterize plasma and tumor extracellular fluid (tECF) pharmacokinetic properties. The murine dosage of SV (100 mg/kg, p.o.) was equivalent to the maximum tolerated dose in patients (7.5 mg/kg, p.o.) based on equivalent plasma exposure of simvastatin acid (SVA) between the two species. SV is rapidly metabolized in murine plasma with 15 times lower exposure compared with human plasma. SVA exposure in tECF was <33.8 ± 11.9 µg/l per hour, whereas the tumor to plasma partition coefficient of SVA was <0.084 ± 0.008. Compared with in vitro washout IC50 values, we did not achieve sufficient exposure of SVA in tECF to suggest tumor growth inhibition; therefore, SV was not carried forward in subsequent preclinical efficacy studies. PMID:26802130

  11. 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.

  12. 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.

  13. 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.

  14. Reliability in the design phase

    SciTech Connect

    Siahpush, A.S.; Hills, S.W.; Pham, H. ); Majumdar, D. )

    1991-12-01

    A study was performed to determine the common methods and tools that are available to calculated or predict a system's reliability. A literature review and software survey are included. The desired product of this developmental work is a tool for the system designer to use in the early design phase so that the final design will achieve the desired system reliability without lengthy testing and rework. Three computer programs were written which provide the first attempt at fulfilling this need. The programs are described and a case study is presented for each one. This is a continuing effort which will be furthered in FY-1992. 10 refs.

  15. Reliability in the design phase

    SciTech Connect

    Siahpush, A.S.; Hills, S.W.; Pham, H.; Majumdar, D.

    1991-12-01

    A study was performed to determine the common methods and tools that are available to calculated or predict a system`s reliability. A literature review and software survey are included. The desired product of this developmental work is a tool for the system designer to use in the early design phase so that the final design will achieve the desired system reliability without lengthy testing and rework. Three computer programs were written which provide the first attempt at fulfilling this need. The programs are described and a case study is presented for each one. This is a continuing effort which will be furthered in FY-1992. 10 refs.

  16. Timely Follow-Up of Abnormal Diagnostic Imaging Test Results in an Outpatient Setting: Are Electronic Medical Records Achieving Their Potential?

    PubMed Central

    Singh, Hardeep; Thomas, Eric J.; Mani, Shrinidi; Sittig, Dean; Arora, Harvinder; Espadas, Donna; Khan, Myrna M.; Petersen, Laura A.

    2010-01-01

    Background Given the fragmentation of outpatient care, timely follow-up of abnormal diagnostic test results remains a challenge. We hypothesized that an EMR that facilitates the transmission and availability of critical imaging results through either automated notification (alerting) or direct access to the primary report would eliminate this problem. Methods We studied critical imaging alert notifications in the outpatient setting of a tertiary care VA facility from November 2007 to June 2008. Tracking software determined whether the alert was acknowledged (i.e. provider opened the message for viewing) within two weeks of transmission; acknowledged alerts were considered read. We reviewed medical records and contacted providers to determine timely follow-up actions (e.g. ordering a follow-up test or consultation) within 4 weeks of transmission. Multivariable logistic regression models accounting for clustering effect by providers analyzed predictors for two outcomes; lack of acknowledgment and lack of timely follow-up. Results Of 123,638 studies (including X-rays, CT scans, ultrasounds, MRI and mammography), 1196 (0.97%) images generated alerts; 217 (18.1%) of these were unacknowledged. Alerts had a higher risk of being unacknowledged when ordering providers were trainees (OR, 5.58;95%CI, 2.86-10.89) and when dual (more than one provider alerted) as opposed to single communication was used (OR, 2.02;95%CI, 1.22-3.36). Timely follow-up was lacking in 92 (7.7% of all alerts) and was similar for acknowledged and unacknowledged alerts (7.3% vs. 9.7%;p=0.2). Risk for lack of timely follow-up was higher with dual communication (OR,1.99;95%CI, 1.06-3.48) but lower when additional verbal communication was used by the radiologist (OR, 0.12;95%CI: 0.04-0.38). Nearly all abnormal results lacking timely follow-up at 4 weeks were eventually found to have measurable clinical impact in terms of further diagnostic testing or treatment. Conclusions Critical imaging results may not

  17. 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

  18. 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.

  19. 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,…

  20. High Reliability and Excellence in Staffing.

    PubMed

    Mensik, Jennifer

    2015-01-01

    Nurse staffing is a complex issue, with many facets and no one right answer. High-reliability organizations (HROs) strive and succeed in achieving a high degree of safety or reliability despite operating in hazardous conditions. HROs have systems in place that make them extremely consistent in accomplishing their goals and avoiding potential errors. However, the inability to resolve quality issues may very well be related to the lack of adoption of high-reliability principles throughout our organizations.

  1. 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

  2. Validation of remote sensed precipitation with the use of hydrological models - methodology and first results achieved in the frame of EUMETSAT H-SAF

    NASA Astrophysics Data System (ADS)

    Lapeta, B.; Niedbala, J. M.; Niedbala, J. S.; Struzik, P.

    2009-04-01

    High variability of precipitation in space and time causes difficulties in proper validation of remote sensed rain rates using conventional ground measurements and observations. Insufficient number and spatial resolution of ground data and their questionable quality make this task even more difficult. Therefore, the idea of independent assessment of the quality of satellite-derived data with the use of operational hydrological models has been implemented in the frame of EUMETSAT. In the paper, the assumptions and methodology of H-SAF hydrological validation will be described. Additionally, the preliminary hydrological validation results obtained for the six month time series of H-SAF precipitation rain rate will be presented. The quality of the rain rate were analyzed using two hydrological model MIKE 11 and Modelling Platform, run in Hydrological Forecasting Office in Krakow, Poland. The differences between the outcomes from these models will be discussed as well.

  3. 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 KR-20 coefficients and…

  4. HELIOS Critical Design Review: Reliability

    NASA Technical Reports Server (NTRS)

    Benoehr, H. C.; Herholz, J.; Prem, H.; Mann, D.; Reichert, L.; Rupp, W.; Campbell, D.; Boettger, H.; Zerwes, G.; Kurvin, C.

    1972-01-01

    This paper presents Helios Critical Design Review Reliability form October 16-20, 1972. The topics include: 1) Reliability Requirement; 2) Reliability Apportionment; 3) Failure Rates; 4) Reliability Assessment; 5) Reliability Block Diagram; and 5) Reliability Information Sheet.

  5. 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…

  6. Early results from an effort to downscale a global dissolved inorganic nitrogen model to achieve a regional assessment of nitrogen dynamics in the Columbia River Basin

    NASA Astrophysics Data System (ADS)

    Miller, C. C.; Harrison, J.

    2013-12-01

    Excessive nitrogen (N) export to coastal systems has increased dramatically since the early 20th century. The increase in N has been linked to significant environmental impacts such as eutrophication, fish kills, and harmful algal blooms and is caused in part by the increasing use and quantity of synthetic fertilizer on farmland. Significant portions of both the Willamette River Valley in Oregon and the Palouse region of eastern Washington are agricultural land, approximately 20% and 57% respectively. Nitrogen in the form of dissolved inorganic nitrogen (DIN) can leach from farms and pasture land into ground and surface water systems. This leaching, combined with DIN in runoff, contributes to the environmental degradation of both waterways (i.e. streams, rivers) and coastal estuaries. Because of this it is important to understand what effects changes in DIN application will have on water quality and DIN export to the coast. DIN export data, retrieved from the U.S. Geological Survey National Water Information System, was analyzed for 23 major subbasins in the Columbia River Basin (CRB) and estimates DIN export (per area yield) ranging from 5.0 to 883.1 kg N km-2 yr-1. Here we present early results from our effort to downscale the Global Nutrient Export from WaterSheds (Global NEWS) DIN model for application within the Columbia River Basin (CRB). This first attempt at downscaling Global NEWS is missing some key higher-resolution N inputs for the model as well as accurate dam retention and runoff factors which could account for the low correlation between model output and observed data (R2 = 0.21).Our regional model predicts DIN yields ranging from 7.9 to 1146.6 kg N km-2 yr-1. Both the model output and observed data predict the highest per area DIN yields occurring in the Willamette river subbasin. Total DIN export to the coast was modeled as 0.06 Tg N yr-1 compared to 0.07 Tg N yr-1 calculated from the measured data. Based on current model inputs biological N2

  7. 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.

  8. 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 measures…

  9. 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 measures…

  10. 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 measures…

  11. 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 measures…

  12. 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.

  13. 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.

  14. 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…

  15. WWC Review of the Report "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." What Works Clearinghouse Single Study Review

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2015

    2015-01-01

    In the 2014 report, "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," researchers examined the impacts of "Tools of the Mind" on cognitive and academic…

  16. Reliability analysis of interdependent lattices

    NASA Astrophysics Data System (ADS)

    Limiao, Zhang; Daqing, Li; Pengju, Qin; Bowen, Fu; Yinan, Jiang; Zio, Enrico; Rui, Kang

    2016-06-01

    Network reliability analysis has drawn much attention recently due to the risks of catastrophic damage in networked infrastructures. These infrastructures are dependent on each other as a result of various interactions. However, most of the reliability analyses of these interdependent networks do not consider spatial constraints, which are found important for robustness of infrastructures including power grid and transport systems. Here we study the reliability properties of interdependent lattices with different ranges of spatial constraints. Our study shows that interdependent lattices with strong spatial constraints are more resilient than interdependent Erdös-Rényi networks. There exists an intermediate range of spatial constraints, at which the interdependent lattices have minimal resilience.

  17. Integrating reliability analysis and design

    SciTech Connect

    Rasmuson, D. M.

    1980-10-01

    This report describes the Interactive Reliability Analysis Project and demonstrates the advantages of using computer-aided design systems (CADS) in reliability analysis. Common cause failure problems require presentations of systems, analysis of fault trees, and evaluation of solutions to these. Results have to be communicated between the reliability analyst and the system designer. Using a computer-aided design system saves time and money in the analysis of design. Computer-aided design systems lend themselves to cable routing, valve and switch lists, pipe routing, and other component studies. At EG and G Idaho, Inc., the Applicon CADS is being applied to the study of water reactor safety systems.

  18. Interrater Reliability of Risk Matrix 2000/s.

    PubMed

    Wakeling, Helen C; Mann, Ruth E; Milner, Rebecca J

    2011-01-01

    Actuarial risk assessment instruments for sexual offenders are often used in high-stakes decision making and therefore should be subject to stringent reliability and validity testing. Furthermore, those involved in the risk assessment of sexual offenders should be aware of the factors that may affect the reliability of these instruments. The present study examined the interrater reliability of the Risk Matrix 2000/s between one field rater and one independent rater with a sample of more than 100 sexual offenders. The results indicated good interrater reliability of the tool, although reliability varies from item to item. A number of factors were identified that seem to reduce the reliability of scoring. The present findings are strengthened by examining interrater reliability of the tool in the usual practitioner context and by calculating a range of reliability statistics. Strategies are suggested to increase reliability in the use of actuarial tools in routine practice. PMID:21216783

  19. Interrater reliability of Risk Matrix 2000/s.

    PubMed

    Wakeling, Helen C; Mann, Ruth E; Milner, Rebecca J

    2011-12-01

    Actuarial risk assessment instruments for sexual offenders are often used in high-stakes decision making and therefore should be subject to stringent reliability and validity testing. Furthermore, those involved in the risk assessment of sexual offenders should be aware of the factors that may affect the reliability of these instruments. The present study examined the interrater reliability of the Risk Matrix 2000/s between one field rater and one independent rater with a sample of more than 100 sexual offenders. The results indicated good interrater reliability of the tool, although reliability varies from item to item. A number of factors were identified that seem to reduce the reliability of scoring. The present findings are strengthened by examining interrater reliability of the tool in the usual practitioner context and by calculating a range of reliability statistics. Strategies are suggested to increase reliability in the use of actuarial tools in routine practice. PMID:22114173

  20. 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.

  1. 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

  2. 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?

  3. An experiment in software reliability

    NASA Technical Reports Server (NTRS)

    Dunham, J. R.; Pierce, J. L.

    1986-01-01

    The results of a software reliability experiment conducted in a controlled laboratory setting are reported. The experiment was undertaken to gather data on software failures and is one in a series of experiments being pursued by the Fault Tolerant Systems Branch of NASA Langley Research Center to find a means of credibly performing reliability evaluations of flight control software. The experiment tests a small sample of implementations of radar tracking software having ultra-reliability requirements and uses n-version programming for error detection, and repetitive run modeling for failure and fault rate estimation. The experiment results agree with those of Nagel and Skrivan in that the program error rates suggest an approximate log-linear pattern and the individual faults occurred with significantly different error rates. Additional analysis of the experimental data raises new questions concerning the phenomenon of interacting faults. This phenomenon may provide one explanation for software reliability decay.

  4. Reliability in aposematic signaling

    PubMed Central

    2010-01-01

    In light of recent work, we will expand on the role and variability of aposematic signals. The focus of this review will be the concepts of reliability and honesty in aposematic signaling. We claim that reliable signaling can solve the problem of aposematic evolution, and that variability in reliability can shed light on the complexity of aposematic systems. PMID:20539774

  5. 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.

  6. Reliability as Argument

    ERIC Educational Resources Information Center

    Parkes, Jay

    2007-01-01

    Reliability consists of both important social and scientific values and methods for evidencing those values, though in practice methods are often conflated with the values. With the two distinctly understood, a reliability argument can be made that articulates the particular reliability values most relevant to the particular measurement situation…

  7. 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.

  8. 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.”

  9. Reliability assurance for regulation of advanced reactors

    SciTech Connect

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

    1991-01-01

    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.

  10. 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.

  11. 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.

  12. Optimization of reliability allocation strategies through use of genetic algorithms

    SciTech Connect

    Campbell, J.E.; Painton, L.A.

    1996-08-01

    This paper examines a novel optimization technique called genetic algorithms and its application to the optimization of reliability allocation strategies. Reliability allocation should occur in the initial stages of design, when the objective is to determine an optimal breakdown or allocation of reliability to certain components or subassemblies in order to meet system specifications. The reliability allocation optimization is applied to the design of a cluster tool, a highly complex piece of equipment used in semiconductor manufacturing. The problem formulation is presented, including decision variables, performance measures and constraints, and genetic algorithm parameters. Piecewise ``effort curves`` specifying the amount of effort required to achieve a certain level of reliability for each component of subassembly are defined. The genetic algorithm evolves or picks those combinations of ``effort`` or reliability levels for each component which optimize the objective of maximizing Mean Time Between Failures while staying within a budget. The results show that the genetic algorithm is very efficient at finding a set of robust solutions. A time history of the optimization is presented, along with histograms or the solution space fitness, MTBF, and cost for comparative purposes.

  13. 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.

  14. 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. PMID:27180287

  15. Improve relief valve reliability

    SciTech Connect

    Nelson, W.E.

    1993-01-01

    This paper reports on careful evaluation of safety relief valves and their service conditions which can improve reliability and permit more time between testing. Some factors that aid in getting long-run results are: Use of valves suitable for service, Attention to design of the relieving system (including use of block valves) and Close attention to repair procedures. Use these procedures for each installation, applying good engineering practices. The Clean Air Act of 1990 and other legislation limiting allowable fugitive emissions in a hydrocarbon processing plant will greatly impact safety relief valve installations. Normal leakage rate from a relief valve will require that it be connected to a closed vent system connected to a recovery or control device. Tying the outlet of an existing valve into a header system can cause accelerated corrosion and operating difficulties. Reliability of many existing safety relief valves may be compromised when they are connected to an outlet header without following good engineering practices. The law has been enacted but all the rules have not been promulgated.

  16. 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.

  17. 76 FR 16240 - Mandatory Reliability Standards for Interconnection Reliability Operating Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    .... Reliability Coordinator's Procedures for 37 Selecting the SOLs for Evaluation by the Interchange Distribution..., Order No. 693, 72 FR 16416 (Apr. 4, 2007), FERC Stats. & Regs. ] 31,242, order on reh'g, Order No. 693-A... reliability coordinator to use analyses and assessments as methods of achieving the stated goal....

  18. 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.

  19. Component Reliability Testing of Long-Life Sorption Cryocoolers

    NASA Technical Reports Server (NTRS)

    Bard, S.; Wu, J.; Karlmann, P.; Mirate, C.; Wade, L.

    1994-01-01

    This paper summarizes ongoing experiments characterizing the ability of critical sorption cryocooler components to achieve highly reliable operation for long-life space missions. Test data obtained over the past several years at JPL are entirely consistent with achieving ten year life for sorption compressors, electrical heaters, container materials, valves, and various sorbent materials suitable for driving 8 to 180 K refrigeration stages. Test results for various compressor systems are reported. Planned future tests necessary to gain a detailed understanding of the sensitivity of cooler performance and component life to operating constraints, design configurations, and fabrication, assembly and handling techniques, are also discussed.

  20. Human reliability analysis

    SciTech Connect

    Dougherty, E.M.; Fragola, J.R.

    1988-01-01

    The authors present a treatment of human reliability analysis incorporating an introduction to probabilistic risk assessment for nuclear power generating stations. They treat the subject according to the framework established for general systems theory. Draws upon reliability analysis, psychology, human factors engineering, and statistics, integrating elements of these fields within a systems framework. Provides a history of human reliability analysis, and includes examples of the application of the systems approach.

  1. Reliability of fluid systems

    NASA Astrophysics Data System (ADS)

    Kopáček, Jaroslav; Fojtášek, Kamil; Dvořák, Lukáš

    2016-03-01

    This paper focuses on the importance of detection reliability, especially in complex fluid systems for demanding production technology. The initial criterion for assessing the reliability is the failure of object (element), which is seen as a random variable and their data (values) can be processed using by the mathematical methods of theory probability and statistics. They are defined the basic indicators of reliability and their applications in calculations of serial, parallel and backed-up systems. For illustration, there are calculation examples of indicators of reliability for various elements of the system and for the selected pneumatic circuit.

  2. Operational safety reliability research

    SciTech Connect

    Hall, R.E.; Boccio, J.L.

    1986-01-01

    Operating reactor events such as the TMI accident and the Salem automatic-trip failures raised the concern that during a plant's operating lifetime the reliability of systems could degrade from the design level that was considered in the licensing process. To address this concern, NRC is sponsoring the Operational Safety Reliability Research project. The objectives of this project are to identify the essential tasks of a reliability program and to evaluate the effectiveness and attributes of such a reliability program applicable to maintaining an acceptable level of safety during the operating lifetime at the plant.

  3. 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.

  4. 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.

  5. 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.

  6. Business of reliability

    NASA Astrophysics Data System (ADS)

    Engel, Pierre

    1999-12-01

    The presentation is organized around three themes: (1) The decrease of reception equipment costs allows non-Remote Sensing organization to access a technology until recently reserved to scientific elite. What this means is the rise of 'operational' executive agencies considering space-based technology and operations as a viable input to their daily tasks. This is possible thanks to totally dedicated ground receiving entities focusing on one application for themselves, rather than serving a vast community of users. (2) The multiplication of earth observation platforms will form the base for reliable technical and financial solutions. One obstacle to the growth of the earth observation industry is the variety of policies (commercial versus non-commercial) ruling the distribution of the data and value-added products. In particular, the high volume of data sales required for the return on investment does conflict with traditional low-volume data use for most applications. Constant access to data sources supposes monitoring needs as well as technical proficiency. (3) Large volume use of data coupled with low- cost equipment costs is only possible when the technology has proven reliable, in terms of application results, financial risks and data supply. Each of these factors is reviewed. The expectation is that international cooperation between agencies and private ventures will pave the way for future business models. As an illustration, the presentation proposes to use some recent non-traditional monitoring applications, that may lead to significant use of earth observation data, value added products and services: flood monitoring, ship detection, marine oil pollution deterrent systems and rice acreage monitoring.

  7. Reliability of genetic networks is evolvable

    NASA Astrophysics Data System (ADS)

    Braunewell, Stefan; Bornholdt, Stefan

    2008-06-01

    Control of the living cell functions with remarkable reliability despite the stochastic nature of the underlying molecular networks—a property presumably optimized by biological evolution. We ask here to what extent the ability of a stochastic dynamical network to produce reliable dynamics is an evolvable trait. Using an evolutionary algorithm based on a deterministic selection criterion for the reliability of dynamical attractors, we evolve networks of noisy discrete threshold nodes. We find that, starting from any random network, reliability of the attractor landscape can often be achieved with only a few small changes to the network structure. Further, the evolvability of networks toward reliable dynamics while retaining their function is investigated and a high success rate is found.

  8. 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.

  9. 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,…

  10. 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…

  11. Reliability-based casing design

    SciTech Connect

    Maes, M.A.; Gulati, K.C.; Johnson, R.C.; McKenna, D.L.; Brand, P.R.; Lewis, D.B.

    1995-06-01

    The present paper describes the development of reliability-based design criteria for oil and/or gas well casing/tubing. The approach is based on the fundamental principles of limit state design. Limit states for tubulars are discussed and specific techniques for the stochastic modeling of loading and resistance variables are described. Zonation methods and calibration techniques are developed which are geared specifically to the characteristic tubular design for both hydrocarbon drilling and production applications. The application of quantitative risk analysis to the development of risk-consistent design criteria is shown to be a major and necessary step forward in achieving more economic tubular design.

  12. Bayesian methods in reliability

    NASA Astrophysics Data System (ADS)

    Sander, P.; Badoux, R.

    1991-11-01

    The present proceedings from a course on Bayesian methods in reliability encompasses Bayesian statistical methods and their computational implementation, models for analyzing censored data from nonrepairable systems, the traits of repairable systems and growth models, the use of expert judgment, and a review of the problem of forecasting software reliability. Specific issues addressed include the use of Bayesian methods to estimate the leak rate of a gas pipeline, approximate analyses under great prior uncertainty, reliability estimation techniques, and a nonhomogeneous Poisson process. Also addressed are the calibration sets and seed variables of expert judgment systems for risk assessment, experimental illustrations of the use of expert judgment for reliability testing, and analyses of the predictive quality of software-reliability growth models such as the Weibull order statistics.

  13. 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.

  14. Novel test fixture for collecting microswitch reliability data

    NASA Astrophysics Data System (ADS)

    Edelmann, Thomas A.; Coutu, Ronald A., Jr.; Starman, LaVern A.

    2010-02-01

    Microelectromechanical systems (MEMS) are an important enabling technology for reducing electronic component geometries and device power consumption. An example of MEMS technology, used in radio frequency (RF) circuits and systems, is the microswitch. Although the operation of microswitches is relatively simple, they are plagued by poor reliability - they must operate over 100 billion cycles. Improvements in the mechanical design of the microswitch have helped to increase their reliability but further improvements are necessary. To accomplish this, research needs to be conducted on the actual contact surfaces for investigation of the mechanical, thermal and electrical phenomena that affect reliability. The focus of this paper is the development of a unique high lifecycle test fixture capable of the simultaneous measurement of contact resistance and contact force. By incorporating a high resonance force sensor, cycle rates reaching 3kHz will be achieved enabling researchers to conduct a wide range of reliability studies. The fixture will be isolated from vibrations and will be housed in a dry-box enclosure to minimize contamination. The test fixture will be automated with control and data acquisition instrumentation to optimize data collection and test repeatability. It is predicted that this new test fixture will provide the potential for significant work to be done to improve the reliability of MEMS microswitches. Several tests were conducted using components of the new test fixture. Preliminary results indicate the feasibility and support the need for the continuing development of this new test fixture.

  15. 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…

  16. 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.

  17. 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.

  18. 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.

  19. 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. PMID:25389751

  20. 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

  1. 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.

  2. 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…

  3. 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…

  4. The Effect of the Adoption of the Quality Philosophy by Teachers on Student Achievement

    ERIC Educational Resources Information Center

    Sandifer, Cody Clark

    2009-01-01

    The purpose of this study was to determine if the adoption of the Deming philosophy by teachers and use of the LtoJ[R] process resulted in greater academic achievement. Results of internal consistency analysis indicated that the instrument, the "Commitment to Quality Inventory for Educators," was a reliable measure of the Deming philosophy for…

  5. Quantitative Comparisons of Difficulty, Discrimination and Reliability of Machine-Scored Completion Items and Tests (in the MDT Un-Cued Answer-Bank Format) in Contrast with Statistics from Comparable Multiple Choice Questions: The First Round of Results.

    ERIC Educational Resources Information Center

    Anderson, Paul S.; Hyers, Albert D.

    Three descriptive statistics (difficulty, discrimination, and reliability) of multiple-choice (MC) test items were compared to those of a new (1980s) format of machine-scored questions. The new method, answer-bank multi-digit testing (MDT), uses alphabetized lists of up to 1,000 alternatives and approximates the completion style of assessment…

  6. 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

  7. Reliable timing systems for computer controlled accelerators

    NASA Astrophysics Data System (ADS)

    Knott, Jürgen; Nettleton, Robert

    1986-06-01

    Over the past decade the use of computers has set new standards for control systems of accelerators with ever increasing complexity coupled with stringent reliability criteria. In fact, with very slow cycling machines or storage rings any erratic operation or timing pulse will cause the loss of precious particles and waste hours of time and effort of preparation. Thus, for the CERN linac and LEAR (Low Energy Antiproton Ring) timing system reliability becomes a crucial factor in the sense that all components must operate practically without fault for very long periods compared to the effective machine cycle. This has been achieved by careful selection of components and design well below thermal and electrical limits, using error detection and correction where possible, as well as developing "safe" decoding techniques for serial data trains. Further, consistent structuring had to be applied in order to obtain simple and flexible modular configurations with very few components on critical paths and to minimize the exchange of information to synchronize accelerators. In addition, this structuring allows the development of efficient strategies for on-line and off-line fault diagnostics. As a result, the timing system for Linac 2 has, so far, been operating without fault for three years, the one for LEAR more than one year since its final debugging.

  8. 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…

  9. Reliability of the Fermilab Antiproton Source

    SciTech Connect

    Harms, E. Jr.

    1993-05-01

    This paper reports on the reliability of the Fermilab Antiproton source since it began operation in 1985. Reliability of the complex as a whole as well as subsystem performance is summarized. Also discussed is the trending done to determine causes of significant machine downtime and actions taken to reduce the incidence of failure. Finally, results of a study to detect previously unidentified reliability limitations are presented.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. HEPEX - achievements and challenges!

    NASA Astrophysics Data System (ADS)

    Pappenberger, Florian; Ramos, Maria-Helena; Thielen, Jutta; Wood, Andy; Wang, Qj; Duan, Qingyun; Collischonn, Walter; Verkade, Jan; Voisin, Nathalie; Wetterhall, Fredrik; Vuillaume, Jean-Francois Emmanuel; Lucatero Villasenor, Diana; Cloke, Hannah L.; Schaake, John; van Andel, Schalk-Jan

    2014-05-01

    HEPEX is an international initiative bringing together hydrologists, meteorologists, researchers and end-users to develop advanced probabilistic hydrological forecast techniques for improved flood, drought and water management. HEPEX was launched in 2004 as an independent, cooperative international scientific activity. During the first meeting, the overarching goal was defined as: "to develop and test procedures to produce reliable hydrological ensemble forecasts, and to demonstrate their utility in decision making related to the water, environmental and emergency management sectors." The applications of hydrological ensemble predictions span across large spatio-temporal scales, ranging from short-term and localized predictions to global climate change and regional modeling. Within the HEPEX community, information is shared through its blog (www.hepex.org), meetings, testbeds and intercompaison experiments, as well as project reportings. Key questions of HEPEX are: * What adaptations are required for meteorological ensemble systems to be coupled with hydrological ensemble systems? * How should the existing hydrological ensemble prediction systems be modified to account for all sources of uncertainty within a forecast? * What is the best way for the user community to take advantage of ensemble forecasts and to make better decisions based on them? This year HEPEX celebrates its 10th year anniversary and this poster will present a review of the main operational and research achievements and challenges prepared by Hepex contributors on data assimilation, post-processing of hydrologic predictions, forecast verification, communication and use of probabilistic forecasts in decision-making. Additionally, we will present the most recent activities implemented by Hepex and illustrate how everyone can join the community and participate to the development of new approaches in hydrologic ensemble prediction.

  17. 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.

  18. The Reliability of Psychiatric Diagnosis Revisited

    PubMed Central

    Rankin, Eric; France, Cheryl; El-Missiry, Ahmed; John, Collin

    2006-01-01

    Background: The authors reviewed the topic of reliability of psychiatric diagnosis from the turn of the 20th century to present. The objectives of this paper are to explore the reasons of unreliability of psychiatric diagnosis and propose ways to improve the reliability of psychiatric diagnosis. Method: The authors reviewed the literature on the concept of reliability of psychiatric diagnosis with emphasis on the impact of interviewing skills, use of diagnostic criteria, and structured interviews on the reliability of psychiatric diagnosis. Results: Causes of diagnostic unreliability are attributed to the patient, the clinician and psychiatric nomenclature. The reliability of psychiatric diagnosis can be enhanced by using diagnostic criteria, defining psychiatric symptoms and structuring the interviews. Conclusions: The authors propose the acronym ‘DR.SED,' which stands for diagnostic criteria, reference definitions, structuring the interview, clinical experience, and data. The authors recommend that clinicians use the DR.SED paradigm to improve the reliability of psychiatric diagnoses. PMID:21103149

  19. Software reliability perspectives

    NASA Technical Reports Server (NTRS)

    Wilson, Larry; Shen, Wenhui

    1987-01-01

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

  20. 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.

  1. Gearbox Reliability Collaborative Update (Presentation)

    SciTech Connect

    Sheng, S.

    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.

  2. Materials reliability issues in microelectronics

    SciTech Connect

    Lloyd, J.R. ); Yost, F.G. ); Ho, P.S. )

    1991-01-01

    This book covers the proceedings of a MRS symposium on materials reliability in microelectronics. Topics include: electromigration; stress effects on reliability; stress and packaging; metallization; device, oxide and dielectric reliability; new investigative techniques; and corrosion.

  3. 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.

  4. Radioactive Reliability of Programmable Memories

    NASA Astrophysics Data System (ADS)

    Loncar, Boris; Osmokrovic, Predrag; Stojanovic, Marko; Stankovic, Srboljub

    2001-02-01

    In this study, we examine the reliability of erasable programmable read only memory (EPROM) and electrically erasable programmable read only memory (EEPROM) components under the influence of gamma radiation. This problem has significance in military industry and space technology. Total dose results are presented for the JL 27C512D EPROM and 28C64C EEPROM components. There is evidence that EPROM components have better radioactive reliability than EEPROM components. Also, the changes to the EPROM are reversible, and after erasing and reprogramming all EPROM components are functional. On the other hand, changes to the EEPROM are irreversible, and under the influence of gamma radiation, all EEPROM components became permanently nonfunctional. The obtained results are analyzed and explained via the interaction of gamma radiation with oxide layers.

  5. 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.

  6. Evaluating Reliability: A Cost-Effectiveness Approach.

    ERIC Educational Resources Information Center

    Hogan, Andrew

    1986-01-01

    This study derives the economic costs of misclassification in nursing home patient classification systems. These costs are then used as weights to estimate the reliability of a functional assessment instrument. Results suggest that reliability must be redefined and remeasured with each substantively new application of an assessment instrument.…

  7. 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…

  8. Quantifying Human Performance Reliability.

    ERIC Educational Resources Information Center

    Askren, William B.; Regulinski, Thaddeus L.

    Human performance reliability for tasks in the time-space continuous domain is defined and a general mathematical model presented. The human performance measurement terms time-to-error and time-to-error-correction are defined. The model and measurement terms are tested using laboratory vigilance and manual control tasks. Error and error-correction…

  9. Grid reliability management tools

    SciTech Connect

    Eto, J.; Martinez, C.; Dyer, J.; Budhraja, V.

    2000-10-01

    To summarize, Consortium for Electric Reliability Technology Solutions (CERTS) is engaged in a multi-year program of public interest R&D to develop and prototype software tools that will enhance system reliability during the transition to competitive markets. The core philosophy embedded in the design of these tools is the recognition that in the future reliability will be provided through market operations, not the decisions of central planners. Embracing this philosophy calls for tools that: (1) Recognize that the game has moved from modeling machine and engineering analysis to simulating markets to understand the impacts on reliability (and vice versa); (2) Provide real-time data and support information transparency toward enhancing the ability of operators and market participants to quickly grasp, analyze, and act effectively on information; (3) Allow operators, in particular, to measure, monitor, assess, and predict both system performance as well as the performance of market participants; and (4) Allow rapid incorporation of the latest sensing, data communication, computing, visualization, and algorithmic techniques and technologies.

  10. 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.

  11. 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.

  12. Wear Mechanisms in a Reliability Methodology

    NASA Astrophysics Data System (ADS)

    Tanner, Danelle M.; Dugger, Michael T.

    2003-01-01

    The main thrust in any reliability work is identifying failure modes and mechanisms. This is especially true for the new technology of MicroElectroMechanical Systems (MEMS). The methods are sometimes just as important as the results achieved. This paper will review some of the methods developed specifically for MEMS. Our methodology uses statistical characterization and testing of complex MEMS devices to help us identify dominant failure modes. We strive to determine the root cause of each failure mode and to gain a fundamental understanding of that mechanism. Test structures designed to be sensitive to a particular failure mechanism are typically used to gain understanding. The development of predictive models follows from this basic understanding. This paper will focus on the failure mechanism of wear and how our methodology was exercised to provide a predictive model. The MEMS device stressed in these studies was a Sandia-developed microengine with orthogonal electrostatic linear actuators connected to a gear on a hub. The dominant failure mechanism was wear in the sliding/contacting regions. A sliding beam-on-post test structure was also used to measure friction coefficients and wear morphology for different surface coatings and environments. Results show that a predictive model of failure-time as a function of drive frequency based on wear fits the functional form of the reliability data quite well, and demonstrates the benefit of a fundamental understanding of wear. The results also show that while debris of similar chemistry and morphology was created in the two types of devices, the dependence of debris generation on the operating environment was entirely different. The differences are discussed in terms of wear maps for ceramics, and the mechanical and thermal contact conditions in each device.

  13. 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.

  14. A Secure Routing Using Reliable 1-Hop Broadcast in Mobile Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Park, Seungjin; Yoo, Seong-Moo

    Among many ways to achieve security in wireless mobile ad hoc networks, the approach taken in this paper is to ensure that all nodes in the network receive critical information on security such as public keys. To achieve this, a reliable global broadcasting of the information must be accomplished, which in turn, relies on a reliable 1-hop broadcasting in which a message from the source node is guaranteed to be delivered to all nodes within the source node's transmission range. This paper presents a MAC protocol that guarantees a reliable and efficient 1-hop broadcast. The unique feature of the proposed algorithm is that each node is able to dynamically adjust its transmission range depending on the node density around it. Simulation results show the effectiveness of the proposed algorithm.

  15. 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.

  16. 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 a 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.

  17. 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.

  18. Fatigue Reliability Analysis of Turbine Disk Alloy Using Saddlepoint Approximation

    NASA Astrophysics Data System (ADS)

    Gan, Luping; Huang, Hong-Zhong; Zhu, Shun-Peng; Li, Yan-Feng; Yang, Yuanjian

    2013-09-01

    In this paper, a new fatigue reliability analysis method based on saddlepoint approximation (SPA) was proposed for calculating the probability of failure of turbine disk alloy in a low cycle fatigue (LCF) regime. Firstly, two LCF life prediction models based on total strain energy density and Support Vector Regression (SVR) metamodel are presented for turbine disk alloy GH4133 under different loading conditions at 250 °C. Compared with the SWT model, modified Walker model and Response Surface (RS) model, the predicted lives by the proposed models are within a factor of ±2 and a factor of ±1.1 respectively. Secondly, based on the fatigue design criteria, the probabilities of failure are calculated using SPA for the explicit and implicit performance functions using two proposed LCF models and viscosity-based model. These three models have provided the reliability design rules for GH4133. Finally, the failure probabilities curves between SPA and the designed fatigue lives are achieved. The reliability analysis results were found to be in good agreement with the calculated results of test data. These results show that SPA is very apt for the fatigue reliability analysis of turbine disk under different loading conditions using only a small number of samples without any distribution assumptions for random variables. Moreover, it can be used to estimate the system's probability of failure with a large number of random variables or high nonlinearity of performance functions. The effectiveness and accuracy of the combination of the fatigue models and SPA for fatigue reliability analysis are verified using three examples.

  19. On-orbit spacecraft reliability

    NASA Technical Reports Server (NTRS)

    Bloomquist, C.; Demars, D.; Graham, W.; Henmi, P.

    1978-01-01

    Operational and historic data for 350 spacecraft from 52 U.S. space programs were analyzed for on-orbit reliability. Failure rates estimates are made for on-orbit operation of spacecraft subsystems, components, and piece parts, as well as estimates of failure probability for the same elements during launch. Confidence intervals for both parameters are also given. The results indicate that: (1) the success of spacecraft operation is only slightly affected by most reported incidents of anomalous behavior; (2) the occurrence of the majority of anomalous incidents could have been prevented piror to launch; (3) no detrimental effect of spacecraft dormancy is evident; (4) cycled components in general are not demonstrably less reliable than uncycled components; and (5) application of product assurance elements is conductive to spacecraft success.

  20. 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.

  1. 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…

  2. Classroom Composition and Achievement Gains.

    ERIC Educational Resources Information Center

    Leiter, Jeffrey

    1983-01-01

    Third-grade students in high ability groups in mathematics achieved greater gains than students in low ability groups. The opposite results occurred in reading achievement. Possible reasons for this difference include different instructional techniques for reading and math and the effect of home environment on learning. (IS)

  3. Reliability in individual monitoring service.

    PubMed

    Mod Ali, N

    2011-03-01

    As a laboratory certified to ISO 9001:2008 and accredited to ISO/IEC 17025, the Secondary Standard Dosimetry Laboratory (SSDL)-Nuclear Malaysia has incorporated an overall comprehensive system for technical and quality management in promoting a reliable individual monitoring service (IMS). Faster identification and resolution of issues regarding dosemeter preparation and issuing of reports, personnel enhancement, improved customer satisfaction and overall efficiency of laboratory activities are all results of the implementation of an effective quality system. Review of these measures and responses to observed trends provide continuous improvement of the system. By having these mechanisms, reliability of the IMS can be assured in the promotion of safe behaviour at all levels of the workforce utilising ionising radiation facilities. Upgradation of in the reporting program through a web-based e-SSDL marks a major improvement in Nuclear Malaysia's IMS reliability on the whole. The system is a vital step in providing a user friendly and effective occupational exposure evaluation program in the country. It provides a higher level of confidence in the results generated for occupational dose monitoring of the IMS, thus, enhances the status of the radiation protection framework of the country.

  4. Reliability in individual monitoring service.

    PubMed

    Mod Ali, N

    2011-03-01

    As a laboratory certified to ISO 9001:2008 and accredited to ISO/IEC 17025, the Secondary Standard Dosimetry Laboratory (SSDL)-Nuclear Malaysia has incorporated an overall comprehensive system for technical and quality management in promoting a reliable individual monitoring service (IMS). Faster identification and resolution of issues regarding dosemeter preparation and issuing of reports, personnel enhancement, improved customer satisfaction and overall efficiency of laboratory activities are all results of the implementation of an effective quality system. Review of these measures and responses to observed trends provide continuous improvement of the system. By having these mechanisms, reliability of the IMS can be assured in the promotion of safe behaviour at all levels of the workforce utilising ionising radiation facilities. Upgradation of in the reporting program through a web-based e-SSDL marks a major improvement in Nuclear Malaysia's IMS reliability on the whole. The system is a vital step in providing a user friendly and effective occupational exposure evaluation program in the country. It provides a higher level of confidence in the results generated for occupational dose monitoring of the IMS, thus, enhances the status of the radiation protection framework of the country. PMID:21147789

  5. 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.

  6. Reliability of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1986-01-01

    In order to assess the reliability of photovoltaic modules, four categories of known array failure and degradation mechanisms are discussed, and target reliability allocations have been developed within each category based on the available technology and the life-cycle-cost requirements of future large-scale terrestrial applications. Cell-level failure mechanisms associated with open-circuiting or short-circuiting of individual solar cells generally arise from cell cracking or the fatigue of cell-to-cell interconnects. Power degradation mechanisms considered include gradual power loss in cells, light-induced effects, and module optical degradation. Module-level failure mechanisms and life-limiting wear-out mechanisms are also explored.

  7. Reliability and durability problems

    NASA Astrophysics Data System (ADS)

    Bojtsov, B. V.; Kondrashov, V. Z.

    The papers presented in this volume focus on methods for determining the stress-strain state of structures and machines and evaluating their reliability and service life. Specific topics discussed include a method for estimating the service life of thin-sheet automotive structures, stressed state at the tip of small cracks in anisotropic plates under biaxial tension, evaluation of the elastic-dissipative characteristics of joints by vibrational diagnostics methods, and calculation of the reliability of ceramic structures for arbitrary long-term loading programs. Papers are also presented on the effect of prior plastic deformation on fatigue damage kinetics, axisymmetric and local deformation of cylindrical parts during finishing-hardening treatments, and adhesion of polymers to diffusion coatings on steels.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. ATLAS reliability analysis

    SciTech Connect

    Bartsch, R.R.

    1995-09-01

    Key elements of the 36 MJ ATLAS capacitor bank have been evaluated for individual probabilities of failure. These have been combined to estimate system reliability which is to be greater than 95% on each experimental shot. This analysis utilizes Weibull or Weibull-like distributions with increasing probability of failure with the number of shots. For transmission line insulation, a minimum thickness is obtained and for the railgaps, a method for obtaining a maintenance interval from forthcoming life tests is suggested.

  14. 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

  15. 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.

  16. Methodology for Physics and Engineering of Reliable Products

    NASA Technical Reports Server (NTRS)

    Cornford, Steven L.; Gibbel, Mark

    1996-01-01

    Physics of failure approaches have gained wide spread acceptance within the electronic reliability community. These methodologies involve identifying root cause failure mechanisms, developing associated models, and utilizing these models to inprove time to market, lower development and build costs and higher reliability. The methodology outlined herein sets forth a process, based on integration of both physics and engineering principles, for achieving the same goals.

  17. 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…

  18. 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.

  19. 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.

  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. 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.

  2. 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.…

  3. 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.

  4. Attribution theory in science achievement

    NASA Astrophysics Data System (ADS)

    Craig, Martin

    Recent research reveals consistent lags in American students' science achievement scores. Not only are the scores lower in the United States compared to other developed nations, but even within the United States, too many students are well below science proficiency scores for their grade levels. The current research addresses this problem by examining potential malleable factors that may predict science achievement in twelfth graders using 2009 data from the National Assessment of Educational Progress (NAEP). Principle component factor analysis was conducted to determine the specific items that contribute to each overall factor. A series of multiple regressions were then analyzed and formed the predictive value of each of these factors for science achievement. All significant factors were ultimately examined together (also using multiple regression) to determine the most powerful predictors of science achievement, identifying factors that predict science achievement, the results of which suggested interventions to strengthen students' science achievement scores and encourage persistence in the sciences at the college level and beyond. Although there is a variety of research highlighting how students in the US are falling behind other developing nations in science and math achievement, as yet, little research has addressed ways of intervening to address this gap. The current research is a starting point, seeking to identify malleable factors that contribute to science achievement. More specifically, this research examined the types of attributions that predict science achievement in twelfth grade students.

  5. Mobility and Reading Achievement.

    ERIC Educational Resources Information Center

    Waters, Theresa Z.

    A study examined the effect of geographic mobility on elementary school students' achievement. Although such mobility, which requires students to make multiple moves among schools, can have a negative impact on academic achievement, the hypothesis for the study was that it was not a determining factor in reading achievement test scores. Subjects…

  6. 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.

  7. A Universal Spring-Probe System for Reliable Probing of Electrochemical Lab-on-a-Chip Devices

    PubMed Central

    Lee, Moon-Keun; Lee, Tae Jae; Choi, Ho Woon; Shin, Su Jeong; Park, Jung Youn; Lee, Seok Jae

    2014-01-01

    For achieve sensitivity in lab-on-a-chip electrochemical detection, more reliable probing methods are required, especially for repeated measurements. Spring-probes are a promising candidate method which can replace needle-like probes and alligator clips that usually produce scratches on the surface of gold electrodes due to the strong physical contacts needed for electrochemical measurements. The superior reliability of amperometric measurements by a spring-probe system was compared with results by conventional probing methods. We demonstrated that a universal spring-probe system would be potentially suitable to achieve high performance in lab-on-a-chip devices using electrochemical detection. PMID:24406857

  8. 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

  9. 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.

  10. 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.

  11. Incursion of water and Cu ions into porous low dielectric constant (LKD) thin films and interconnects resulting in damage, time dependent dielectric breakdown (TDDB) and decreased lifetime and reliability

    NASA Astrophysics Data System (ADS)

    Laibowitz, Robert; Raja, Archana; Shaw, Thomas; Liniger, Eric; Cohen, Stephan; Columbia University Collaboration; IBM Research Division Collaboration

    Porous dielectrics, their interfaces and related processing details provide many opportunities for water and Cu incursion. The Cu typically starts as part of the electrode and needs a liner to keep it away from the dielectric. As scaling continues thinner liners and imperfections in the in the liner layer can expose the CU to the LKD. This will lead to TDDD with greatly reduced lifetimes. Water exposure can come from processing or through defects in the passivation layer. Most studies of these breakdown effects have been accomplished using accelerated DC measurements in which the sample is destroyed. Dielectric relaxation provides a new set of measurements at low fields, low temperatures and reusable samples. In this way we have observed the presence of both physisorbed and chemisorbed water, determined their activation energy of motion and removal of the water by various annealing protocols. Initial measurements of Cu incursion have also been made. Preliminary measurement of samples containing Cu and water and processing damage show reduced reliability. We also have begun studies to determine the minimum liner thickness. .

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Fault Tree Reliability Analysis and Design-for-reliability

    1998-05-05

    WinR provides a fault tree analysis capability for performing systems reliability and design-for-reliability analyses. The package includes capabilities for sensitivity and uncertainity analysis, field failure data analysis, and optimization.

  17. 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

  18. 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.

  19. 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.

  20. On Component Reliability and System Reliability for Space Missions

    NASA Technical Reports Server (NTRS)

    Chen, Yuan; Gillespie, Amanda M.; Monaghan, Mark W.; Sampson, Michael J.; Hodson, Robert F.

    2012-01-01

    This paper is to address the basics, the limitations and the relationship between component reliability and system reliability through a study of flight computing architectures and related avionics components for NASA future missions. Component reliability analysis and system reliability analysis need to be evaluated at the same time, and the limitations of each analysis and the relationship between the two analyses need to be understood.

  1. 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.

  2. 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.

  3. 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.

  4. Reliability and Factorial Validity of the Student Development Inventory.

    ERIC Educational Resources Information Center

    Jackson, Lorraine Morlock; And Others

    1985-01-01

    The Student Development Inventory and its seven subscales were administered to 163 college students to determine its reliability and factorial validity. Results suggested that it is a reliable and convenient attitudinal inventory. (Sample items are included.) (Author/GDC)

  5. Apogee motor rocketry reliability improvements

    NASA Technical Reports Server (NTRS)

    Behm, J.; Dowler, W.; Gin, W.

    1974-01-01

    Since 1963, solid propellant apogee motors have been placing satellites into geosynchronous orbits. Major technological breakthroughs are not required to satisfy future mission requirements; however, there is a need to improve reliability to enhance cost effectiveness. Several management test options are discussed. A summary of results and conclusions derived from review of missions, where failure of a solid motor was inferred, and correlation of system factors with failures are reported. Highlights of a solid motor diagnostic instrumentation study are presented. Finally, recommendations are provided for areas of future apogee motor upgrade, which will increase project cost effectiveness by reducing the potential for future flight failures.

  6. 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).

  7. 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.

  8. 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.

  9. Mathematics anxiety and mathematics achievement

    NASA Astrophysics Data System (ADS)

    Sherman, Brian F.; Wither (Post.), David P.

    2003-09-01

    This paper is a distillation of the major result from the 1998 Ph.D. thesis of the late David Wither. It details a longitudinal study over five years of the relationship between mathematics anxiety and mathematics achievement. It starts from the already well documented negative correlation between the two, and seeks to establish one of the three hypotheses—that mathematics anxiety causes an impairment of mathematics achievement; that lack of mathematics achievement causes mathematics anxiety; or that there is a third underlying cause of the two.

  10. 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

  11. 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.

  12. 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.

  13. 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…

  14. Factor reliability into load management

    SciTech Connect

    Feight, G.R.

    1983-07-01

    Hardware reliability is a major factor to consider when selecting a direct-load-control system. The author outlines a method of estimating present-value costs associated with system reliability. He points out that small differences in receiver reliability make a significant difference in owning cost. 4 figures.

  15. Optimum Reliability of Gain Scores.

    ERIC Educational Resources Information Center

    Sharma, K. K.; Gupta, J. K.

    1986-01-01

    This paper gives a mathematical treatment to findings of Zimmerman and Williams and establishes a minimum reliability for gain scores when the pretest and posttest have equal reliabilities and equal standard deviations. It discusses the behavior of the reliability of gain scores in terms of variations in other test parameters. (Author/LMO)

  16. 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

  17. 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.

  18. 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.

  19. Analyzing network reliability using structural motifs

    NASA Astrophysics Data System (ADS)

    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.

  20. 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.

  1. 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.

  2. General Achievement Trends: Oklahoma

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  3. General Achievement Trends: Georgia

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  4. General Achievement Trends: Nebraska

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  5. General Achievement Trends: Arkansas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  6. General Achievement Trends: Maryland

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  7. General Achievement Trends: Maine

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  8. General Achievement Trends: Iowa

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  9. General Achievement Trends: Texas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  10. General Achievement Trends: Hawaii

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  11. General Achievement Trends: Kansas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  12. General Achievement Trends: Florida

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  13. General Achievement Trends: Massachusetts

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  14. General Achievement Trends: Tennessee

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  15. General Achievement Trends: Alabama

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  16. General Achievement Trends: Virginia

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  17. General Achievement Trends: Michigan

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  18. General Achievement Trends: Colorado

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  19. Inverting the Achievement Pyramid

    ERIC Educational Resources Information Center

    White-Hood, Marian; Shindel, Melissa

    2006-01-01

    Attempting to invert the pyramid to improve student achievement and increase all students' chances for success is not a new endeavor. For decades, educators have strategized, formed think tanks, and developed school improvement teams to find better ways to improve the achievement of all students. Currently, the No Child Left Behind Act (NCLB) is…

  20. Achievement Test Program.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Education, Columbus. Trade and Industrial Education Service.

    The Ohio Trade and Industrial Education Achievement Test battery is comprised of seven basic achievement tests: Machine Trades, Automotive Mechanics, Basic Electricity, Basic Electronics, Mechanical Drafting, Printing, and Sheet Metal. The tests were developed by subject matter committees and specialists in testing and research. The Ohio Trade and…

  1. School Effects on Achievement.

    ERIC Educational Resources Information Center

    Nichols, Robert C.

    The New York State Education Department conducts a Pupil Evaluation Program (PEP) in which each year all third, sixth, and ninth grade students in the state are given a series of achievement tests in reading and mathematics. The data accumulated by the department includes achievement test scores, teacher characteristics, building and curriculum…

  2. 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…

  3. 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…

  4. Achieving Public Schools

    ERIC Educational Resources Information Center

    Abowitz, Kathleen Knight

    2011-01-01

    Public schools are functionally provided through structural arrangements such as government funding, but public schools are achieved in substance, in part, through local governance. In this essay, Kathleen Knight Abowitz explains the bifocal nature of achieving public schools; that is, that schools are both subject to the unitary Public compact of…

  5. 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.

  6. Scheduling for energy and reliability management on multiprocessor real-time systems

    NASA Astrophysics Data System (ADS)

    Qi, Xuan

    Scheduling algorithms for multiprocessor real-time systems have been studied for years with many well-recognized algorithms proposed. However, it is still an evolving research area and many problems remain open due to their intrinsic complexities. With the emergence of multicore processors, it is necessary to re-investigate the scheduling problems and design/develop efficient algorithms for better system utilization, low scheduling overhead, high energy efficiency, and better system reliability. Focusing cluster schedulings with optimal global schedulers, we study the utilization bound and scheduling overhead for a class of cluster-optimal schedulers. Then, taking energy/power consumption into consideration, we developed energy-efficient scheduling algorithms for real-time systems, especially for the proliferating embedded systems with limited energy budget. As the commonly deployed energy-saving technique (e.g. dynamic voltage frequency scaling (DVFS)) will significantly affect system reliability, we study schedulers that have intelligent mechanisms to recuperate system reliability to satisfy the quality assurance requirements. Extensive simulation is conducted to evaluate the performance of the proposed algorithms on reduction of scheduling overhead, energy saving, and reliability improvement. The simulation results show that the proposed reliability-aware power management schemes could preserve the system reliability while still achieving substantial energy saving.

  7. Ensuring reliability in UK written tests of general practice: the MRCGP examination 1998-2003.

    PubMed

    Munro, Neil; Denney, Mei Ling; Rughani, Amar; Foulkes, John; Wilson, Andrew; Tate, Peter

    2005-01-01

    Reliability in written examinations is taken very seriously by examination boards and candidates alike. Within general education many factors influence reliability including variations between markers, within markers, within candidates and within teachers. Mechanisms designed to overcome, or at least minimize, the impact of such variables are detailed. Methods of establishing reliability are also explored in the context of a range of assessment situations. In written tests of general practice within the Membership of the Royal College of General Practitioner (MRCGP) examination considerable effort has put been put into achieving acceptable levels of reliability. Current mechanisms designed to ensure high reliability are described and related to the evolution of the written component of the examination. In addition to description of marker selection and training, question development including construct a detailed example of specific and generic marking schedules is provided. Examination results for the Written Paper of the MRCGP from 1998 to 2003 are reported including Cronbach's alpha coefficients and standard error of measurements, mean scores (and SD) and pass rates. In addition individual discrimination scores for each question in the October 2002 paper are shown. Consistent high reliability of the written component of the MRCGP examination provides valuable lessons in terms of selection, training and monitoring of markers as well as practical methods of moderating factors affecting candidate variability. The challenge for examination developers is to carry these important lessons forward into a modernized assessment structure of UK general practice. PMID:16147769

  8. Reliability Generalization of the Revised Children's Manifest Anxiety Scale

    ERIC Educational Resources Information Center

    Ryngala, Donna J.; Shields, Alan L.; Caruso, John C.

    2005-01-01

    A reliability generalization of the Revised Children's Manifest Anxiety Scale (RCMAS) was conducted using the normative sample. The RCMAS consists of a Total Anxiety scale as well as four subscales. Results suggest that the Total Anxiety scores are typically reliable (median across 48 samples = .81). Subscale scores were less reliable: The median…

  9. 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.

  10. 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.

  11. 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.

  12. Disclosure analysis procedures: reliability issues.

    PubMed

    Hux, K; Sanger, D; Reid, R; Maschka, A

    1997-01-01

    Performing disclosure analyses to supplement assessment procedures and facilitate intervention planning is only valuable if the observations are reliable. The purpose of the present study was to evaluate and compare four methods of assessing reliability on one discourse analysis procedure--a modified version of Damico's Clinical Discourse Analysis (1985a, 1985b, 1992). The selected methods were: (a) Pearson product-moment correlations, (b) interobserver agreement, (c) Cohen's kappa, and (d) generalizability coefficients. Results showed high correlation coefficients and high percentages of interobserver agreement when error type was not taken into account. However, interobserver agreement percentages obtained solely for target behavior occurrences and Cohen's kappa revealed that much of the agreement between rates was due to chance and the high frequency of target behavior non-occurrence. Generalizability coefficients revealed that the procedure was fair to good for discriminating among persons with differing levels of language competency for some aspects of communication performance but was less than desirable for others; the aggregate score was below recommended standards for differentiating among people for diagnostic purposes.

  13. Learning environment, motivation, and achievement in high school science

    NASA Astrophysics Data System (ADS)

    Bobbitt Nolen, Susan

    2003-04-01

    In a study of the relationship between high school students' perceptions of their science learning environments and their motivation, learning strategies, and achievement, 377 students in 22 introductory science classrooms completed surveys in the fall and spring of their ninth-grade year. Hierarchical linear regression was used to model the effects of variables at both the classroom and individual level simultaneously. High intraclass agreement (indicated by high parameter reliability) on all classroom environment measures indicated that students shared perceptions of the classroom learning environment. Controlling for other factors, shared perceptions that only the most able could succeed in science classrooms and that instruction was fast-paced and focused on correct answers negatively predicted science achievement, as measured on a districtwide curriculum-linked test. Shared perceptions that classrooms focused on understanding and independent thinking positively predicted students' self-reported satisfaction with learning. Implications of these results for both teaching and research into classroom environments are discussed.

  14. Effects of Extensive Engagement with Computer-Based Reading and Language Arts Instructional Software on Reading Achievement for Sixth Graders

    ERIC Educational Resources Information Center

    Securro, Samuel, Jr.; Jones, Jerry D.; Cantrell, Danny R.

    2010-01-01

    K-12 school practitioners and schools administrators need reliable results about the effects of instructional technology products as they strive to meet achievement compliance levels in politically accountable local and national contexts in the U.S. This study presents evidence regarding the effects of extensive engagement with computer-based…

  15. Student Achievement and Motivation

    ERIC Educational Resources Information Center

    Flammer, Gordon H.; Mecham, Robert C.

    1974-01-01

    Compares the lecture and self-paced methods of instruction on the basis of student motivation and achieveme nt, comparing motivating and demotivating factors in each, and their potential for motivation and achievement. (Authors/JR)

  16. 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

  17. Are specialist certification examinations a reliable measure of physician competence?

    PubMed

    Burch, V C; Norman, G R; Schmidt, H G; van der Vleuten, C P M

    2008-11-01

    High stakes postgraduate specialist certification examinations have considerable implications for the future careers of examinees. Medical colleges and professional boards have a social and professional responsibility to ensure their fitness for purpose. To date there is a paucity of published data about the reliability of specialist certification examinations and objective methods for improvement. Such data are needed to improve current assessment practices and sustain the international credibility of specialist certification processes. To determine the component and composite reliability of the Fellowship examination of the College of Physicians of South Africa, and identify strategies for further improvement, generalizability and multivariate generalizability theory were used to estimate the reliability of examination subcomponents and the overall reliability of the composite examination. Decision studies were used to identify strategies for improving the composition of the examination. Reliability coefficients of the component subtests ranged from 0.58 to 0.64. The composite reliability of the examination was 0.72. This could be increased to 0.8 by weighting all test components equally or increasing the number of patient encounters in the clinical component of the examination. Correlations between examination components were high, suggesting that similar parameters of competence were being assessed. This composite certification examination, if equally weighted, achieved an overall reliability sufficient for high stakes examination purposes. Increasing the weighting of the clinical component decreased the reliability. This could be rectified by increasing the number of patient encounters in the examination. Practical ways of achieving this are suggested.

  18. 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.

  19. 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.

  20. 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.

  1. 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. PMID:19006802

  2. 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.

  3. 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

  4. Reliability sensitivity-based correlation coefficient calculation in structural reliability analysis

    NASA Astrophysics Data System (ADS)

    Yang, Zhou; Zhang, Yimin; Zhang, Xufang; Huang, Xianzhen

    2012-05-01

    The correlation coefficients of random variables of mechanical structures are generally chosen with experience or even ignored, which cannot actually reflect the effects of parameter uncertainties on reliability. To discuss the selection problem of the correlation coefficients from the reliability-based sensitivity point of view, the theory principle of the problem is established based on the results of the reliability sensitivity, and the criterion of correlation among random variables is shown. The values of the correlation coefficients are obtained according to the proposed principle and the reliability sensitivity problem is discussed. Numerical studies have shown the following results: (1) If the sensitivity value of correlation coefficient ρ is less than (at what magnitude 0.000 01), then the correlation could be ignored, which could simplify the procedure without introducing additional error. (2) However, as the difference between ρ s, that is the most sensitive to the reliability, and ρ R , that is with the smallest reliability, is less than 0.001, ρ s is suggested to model the dependency of random variables. This could ensure the robust quality of system without the loss of safety requirement. (3) In the case of | E abs|>0.001 and also | E rel|>0.001, ρ R should be employed to quantify the correlation among random variables in order to ensure the accuracy of reliability analysis. Application of the proposed approach could provide a practical routine for mechanical design and manufactory to study the reliability and reliability-based sensitivity of basic design variables in mechanical reliability analysis and design.

  5. Lithium battery safety and reliability

    NASA Astrophysics Data System (ADS)

    Levy, Samuel C.

    Lithium batteries have been used in a variety of applications for a number of years. As their use continues to grow, particularly in the consumer market, a greater emphasis needs to be placed on safety and reliability. There is a useful technique which can help to design cells and batteries having a greater degree of safety and higher reliability. This technique, known as fault tree analysis, can also be useful in determining the cause of unsafe behavior and poor reliability in existing designs.

  6. 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.

  7. Confidence bounds on structural reliability

    NASA Astrophysics Data System (ADS)

    Mehta, S. R.; Cruse, T. A.; Mahadevan, S.

    1993-04-01

    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.

  8. 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.

  9. Simultaneous determination of propofol and its glucuronide in whole blood by liquid chromatography-electrospray tandem mass spectrometry and the influence of sample storage conditions on the reliability of the test results.

    PubMed

    Sørensen, Lambert K; Hasselstrøm, Jørgen B

    2015-05-10

    Propofol (2,6-diisopropylphenol) is commonly used as an anaesthetic agent but is also abused for recreational purposes. Several cases of fatalities involving self-administered propofol have been reported. For rapid quantification of propofol and propofol β-d-glucuronide (propofol G) in clinical and forensic cases, an ultra-performance liquid chromatography-tandem mass spectrometry method using pneumatically assisted electrospray ionisation has been developed. The technique has been validated on both ante-mortem and post-mortem human whole blood. The proteins in the blood samples were removed by the addition of a mixture of methanol and acetonitrile, and the extract was cleaned up by solid phase extraction. The extract was concentrated in dimethyl sulphoxide. The system was calibrated using matrix-matched calibrants combined with isotope dilution. The lower limits of quantification were 0.01 and 0.02mg/L for propofol and 0.02 and 0.04mg/L for propofol G in ante-mortem and post-mortem whole blood, respectively. The relative intra-laboratory reproducibility standard deviation was less than 10% at concentrations of 0.2mg/L or higher. The mean true extraction recovery was 85% for propofol and 81% for propofol G. The trueness of the propofol determination expressed as the relative bias of the test results was within ±6% at concentration levels of 0.01-8.5mg/L. Propofol was less stable in blood stabilised with a citrate-EDTA-fluoride mixture than in blood stabilised with an oxalate-fluoride mixture. The stability was lower at -20°C than at 5°C and -80°C. Propofol G did not show instability under the storage conditions tested.

  10. Confirmatory Factor Analysis of Achieving the Beginning Teacher Standards Inventory

    ERIC Educational Resources Information Center

    Chen, Weiyun

    2009-01-01

    The purpose of this study was to examine the factorial validity and reliability of the "Achieving the NASPE Standards Inventory (ANSI)" that assesses pre-service physical education teachers' perceptions of achieving the National Association for Sport and Physical Education (NASPE) beginning teacher standards (2003). Four hundred fifty-two…

  11. Construct validity and reliability of college students' responses to the reasons for smoking scale.

    PubMed

    Fiala, Kelly Ann; D'Abundo, Michelle Lee; Marinaro, Laura Marie

    2010-01-01

    When utilizing self-assessments to determine motives for health behaviors, it is essential that the resulting data demonstrate sound psychometric properties. The purpose of this research was to assess the reliability and construct validity of college students' responses to the Reasons for Smoking Scale (RFS). Confirmatory factor analyses and internal consistency reliability coefficients were completed. The data of 110 college students who smoke fell short of providing a good fit, chi2(130) = 343.856, root mean square error of approximation (RMSEA) = 0.123, comparative fit index (CFI) = 0.793, Tucker-Lewis index (TLI) = 0.756. Reliability coefficients ranged from .615 to .912. Three subscales improved reliability by removing an item. Although the fit indices showed improvement with these modifications, good model fit was still not achieved, chi2(50) = 148.059, RMSEA = 0.134, CFI = 0.872, TLI = 0.831. Although other populations' responses to the RFS have demonstrated validity and reliability, this college population's did not. Health educators should use caution when interpreting the results of college students' responses to the RFS because they may be incomplete and/or inaccurate.

  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. SMART reliability mechanism for very large storage systems

    NASA Astrophysics Data System (ADS)

    Luo, Dongjian; Zhong, Haifeng; Pei, Canhao; Wu, Wei; Zhang, Chengfeng

    2008-12-01

    In this paper, we investigate the reliability in a petabyte scale storage system built from thousands of Object-Based Storage Devices and study the mechanisms to protect data loss when disk failure happens. We delve in two underlying redundancy mechanisms: 2-way mirroring, 3-way mirroring. To accelerate data reconstruction, Fast Mirroring Copy is employed where the reconstructed objects are stored on different OBSDs throughout the system. A SMART reliability for enhancing the reliability in very large-scale storage system is proposed. Results show that our SMART Reliability Mechanism can utilize the spare resources (including processing, network, and storage resources) to improve the reliability in very large storage systems.

  17. 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,…

  18. 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…

  19. Leadership Issues: Raising Achievement.

    ERIC Educational Resources Information Center

    Horsfall, Chris, Ed.

    This document contains five papers examining the meaning and operation of leadership as a variable affecting student achievement in further education colleges in the United Kingdom. "Introduction" (Chris Horsfall) discusses school effectiveness studies' findings regarding the relationship between leadership and effective schools, distinguishes…

  20. Achievements or Disasters?

    ERIC Educational Resources Information Center

    Goodwin, MacArthur

    2000-01-01

    Focuses on policy issues that have affected arts education in the twentieth century, such as: interest in discipline-based arts education, influence of national arts associations, and national standards and coordinated assessment. States that whether the policy decisions are viewed as achievements or disasters are for future determination. (CMK)

  1. Achieving True Consensus.

    ERIC Educational Resources Information Center

    Napier, Rod; Sanaghan, Patrick

    2002-01-01

    Uses the example of Vermont's Middlebury College to explore the challenges and possibilities of achieving consensus about institutional change. Discusses why, unlike in this example, consensus usually fails, and presents four demands of an effective consensus process. Includes a list of "test" questions on successful collaboration. (EV)

  2. School Students' Science Achievement

    ERIC Educational Resources Information Center

    Shymansky, James; Wang, Tzu-Ling; Annetta, Leonard; Everett, Susan; Yore, Larry D.

    2013-01-01

    This paper is a report of the impact of an externally funded, multiyear systemic reform project on students' science achievement on a modified version of the Third International Mathematics and Science Study (TIMSS) test in 33 small, rural school districts in two Midwest states. The systemic reform effort utilized a cascading leadership strategy…

  3. Assessing Handwriting Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Teachers in the school setting need to emphasize quality handwriting across the curriculum. Quality handwriting means that the written content is easy to read in either manuscript or cursive form. Handwriting achievement can be assessed, but not compared to the precision of assessing basic addition, subtraction, multiplication, and division facts.…

  4. Intelligence and Educational Achievement

    ERIC Educational Resources Information Center

    Deary, Ian J.; Strand, Steve; Smith, Pauline; Fernandes, Cres

    2007-01-01

    This 5-year prospective longitudinal study of 70,000+ English children examined the association between psychometric intelligence at age 11 years and educational achievement in national examinations in 25 academic subjects at age 16. The correlation between a latent intelligence trait (Spearman's "g"from CAT2E) and a latent trait of educational…

  5. 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.

  6. 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 potential "Robin Hood…

  7. 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…

  8. INTELLIGENCE, PERSONALITY AND ACHIEVEMENT.

    ERIC Educational Resources Information Center

    MUIR, R.C.; AND OTHERS

    A LONGITUDINAL DEVELOPMENTAL STUDY OF A GROUP OF MIDDLE CLASS CHILDREN IS DESCRIBED, WITH EMPHASIS ON A SEGMENT OF THE RESEARCH INVESTIGATING THE RELATIONSHIP OF ACHIEVEMENT, INTELLIGENCE, AND EMOTIONAL DISTURBANCE. THE SUBJECTS WERE 105 CHILDREN AGED FIVE TO 6.3 ATTENDING TWO SCHOOLS IN MONTREAL. EACH CHILD WAS ASSESSED IN THE AREAS OF…

  9. 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…

  10. 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…

  11. Issues in Modeling System Reliability

    NASA Astrophysics Data System (ADS)

    Cruse, Thomas A.; Annis, Chuck; Booker, Jane; Robinson, David; Sues, Rob

    2002-10-01

    This paper discusses various issues in modeling system reliability. The topics include: 1) Statistical formalisms versus pragmatic numerics; 2) Language; 3) Statistical methods versus reliability-based design methods; 4) Professional bias; and 5) Real issues that need to be identified and resolved prior to certifying designs. This paper is in viewgraph form.

  12. Avionics design for reliability bibliography

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A bibliography with abstracts was presented in support of AGARD lecture series No. 81. The following areas were covered: (1) program management, (2) design for high reliability, (3) selection of components and parts, (4) environment consideration, (5) reliable packaging, (6) life cycle cost, and (7) case histories.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. The impact of reliability on naval aviation operations

    NASA Astrophysics Data System (ADS)

    Lashbrooke, D. P.

    The Gulf war illustrated the effectiveness of Naval helicopters, as well as the impact of reliability on rapidly fitted new equipment. Poor reliability can lead to reduced effectiveness, inadequate spares, high cost, and increased risk to human life. Only limited improvements can be achieved in service so the Navy's Aircraft Support Executive has developed ways of targeting equipment having the most adverse effect. The Merlin will need much higher standards of reliability before it enters service, because of its complexity and the cramped confines from which it will operate.

  18. A forward view on reliable computers for flight control

    NASA Technical Reports Server (NTRS)

    Goldberg, J.; Wensley, J. H.

    1976-01-01

    The requirements for fault-tolerant computers for flight control of commercial aircraft are examined; it is concluded that the reliability requirements far exceed those typically quoted for space missions. Examination of circuit technology and alternative computer architectures indicates that the desired reliability can be achieved with several different computer structures, though there are obvious advantages to those that are more economic, more reliable, and, very importantly, more certifiable as to fault tolerance. Progress in this field is expected to bring about better computer systems that are more rigorously designed and analyzed even though computational requirements are expected to increase significantly.

  19. Changes in Achievement Motivation among University Freshmen

    ERIC Educational Resources Information Center

    Dresel, Markus; Grassinger, Robert

    2013-01-01

    Changes in achievement motivation over the first semester of university studies were examined with N = 229 freshmen, who were surveyed twice in the present study. Students' academic self-concepts, achievement goals, and subjective values were chosen as theoretically central components of achievement motivation. The results indicated significant…

  20. 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

  1. 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),…

  2. The establisment of an achievement test for determination of primary teachers' knowledge level of earthquake

    NASA Astrophysics Data System (ADS)

    Aydin, Süleyman; Haşiloǧlu, M. Akif; Kunduraci, Ayşe

    2016-04-01

    In this study it was aimed to improve an academic achievement test to establish the students' knowledge about the earthquake and the ways of protection from earthquakes. In the method of this study, the steps that Webb (1994) was created to improve an academic achievement test for a unit were followed. In the developmental process of multiple choice test having 25 questions, was prepared to measure the pre-service teachers' knowledge levels about the earthquake and the ways of protection from earthquakes. The multiple choice test was presented to view of six academics (one of them was from geographic field and five of them were science educator) and two expert teachers in science Prepared test was applied to 93 pre-service teachers studying in elementary education department in 2014-2015 academic years. As a result of validity and reliability of the study, the test was composed of 20 items. As a result of these applications, Pearson Moments Multiplication half-reliability coefficient was found to be 0.94. When this value is adjusted according to Spearman Brown reliability coefficient the reliability coefficient was set at 0.97.

  3. 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.

  4. 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.

  5. Reliability and validity of an instrument for the assessment of bradykinesia.

    PubMed

    Mentzel, Thierry Q; Lieverse, Ritsaert; Levens, Amar; Mentzel, Charlotte L; Tenback, Diederik E; Bakker, P Rob; Daanen, Hein A M; van Harten, Peter N

    2016-04-30

    Bradykinesia is associated with reduced quality of life and medication non-compliance, and it may be a prodrome for schizophrenia. Therefore, screening/monitoring for subtle bradykinesia is of clinical and scientific importance. This study investigated the validity and reliability of such an instrument. Included were 70 patients with psychotic disorders. Inertial sensors captured mean cycle duration, amplitude and velocity of four movement tasks: walking, elbow flexion/extension, forearm pronation/supination and leg agility. The concurrent validity with the Unified Parkinson's Disease Rating Scale (UPDRS) bradykinesia subscale was determined using regression analysis. Reliability was investigated with the intra-class correlation coefficient. The duration, amplitude and velocities of the four tasks measured by the instrument explained 67% of the variance on the UPDRS bradykinesia subscale. The instrument test-retest reliability was high. The instrument investigated in this study is a valid and reliable alternative to observer-rated scales. It is an ideal tool for monitoring bradykinesia as it requires little training and experience to achieve reliable results. PMID:27086232

  6. Capacitive RF MEMS switch dielectric charging and reliability: a critical review with recommendations

    NASA Astrophysics Data System (ADS)

    van Spengen, W. M.

    2012-07-01

    This paper presents a comprehensive review of the reliability issues hampering capacitive RF MEMS switches in their development toward commercialization. Dielectric charging and its effects on device behavior are extensively addressed, as well as the application of different dielectric materials, improvements in the mechanical design and the use of advanced actuation waveforms. It is concluded that viable capacitive RF MEMS switches with a great chance of market acceptance preferably have no actuation voltage across a dielectric at all, contrary to the ‘standard’ geometry. This is substantiated by the reliability data of a number of dielectric-less MEMS switch designs. However, a dielectric can be used for the signal itself, resulting in a higher Con/Coff ratio than that one would be able to achieve in a switch without any dielectric. The other reliability issues of these devices are also covered, such as creep, RF-power-related failures and packaging reliability. This paper concludes with a recipe for a conceptual ‘ideal’ switch from a reliability point of view, based on the lessons learned.

  7. 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

  8. 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. PMID:26072249

  9. 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.

  10. 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

  11. [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.

  12. 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.

  13. 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.

  14. The reliable operation of CRYEBIS 1

    NASA Astrophysics Data System (ADS)

    Faure, J.

    1989-06-01

    CRYEBIS has been built in ORSAY UNIVERSITY by ARIANER group as a heavy ions source for SATURNE. It was foreseen to use it to ionise polarised hydrogen and deuterium atoms too. In spite of very encouraging results at the very beginning of the experiments, in ORSAY, CRYEBIS 1 delivered very modest heavy ions beams without any reliability. It was decided, in 1980, to set it up, in SACLAY, near to SATURNE, to try to improve the performances and to adapt it with the usual reliability necessary in the vicinity of a 24 hours a day running accelerator.

  15. 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

  16. A reliability-based track fusion algorithm.

    PubMed

    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.

  17. How reliable are human phylogenetic hypotheses?

    PubMed Central

    Collard, Mark; Wood, Bernard

    2000-01-01

    Cladistic analysis of cranial and dental evidence has been widely used to generate phylogenetic hypotheses about humans and their fossil relatives. However, the reliability of these hypotheses has never been subjected to external validation. To rectify this, we applied identical methods to equivalent evidence from two groups of extant higher primates for whom reliable molecular phylogenies are available, the hominoids and papionins. We found that the phylogenetic hypotheses based on the craniodental data were incompatible with the molecular phylogenies for the groups. Given the robustness of the molecular phylogenies, these results indicate that little confidence can be placed in phylogenies generated solely from higher primate craniodental evidence. The corollary of this is that existing phylogenetic hypotheses about human evolution are unlikely to be reliable. Accordingly, new approaches are required to address the problem of hominin phylogeny. PMID:10781112

  18. 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.

  19. (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.

  20. 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…

  1. 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)

  2. 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...

  3. How Reliable are MSCA Profile Interpretations?

    ERIC Educational Resources Information Center

    Roffe, Michael W.; Bryant, Christy K.

    1979-01-01

    This study evaluates the reliability of profile analysis for assessing differential abilities on the McCarthy Scales for Children's Abilities (MSCA). Subjects were enrolled in private schools. Results indicated 70.9 percent of the sample showed profile variability not reasonably accounted for as real fluctuations in measurable abilities. (Author)

  4. TIGER reliability analysis in the DSN

    NASA Technical Reports Server (NTRS)

    Gunn, J. M.

    1982-01-01

    The TIGER algorithm, the inputs to the program and the output are described. TIGER is a computer program designed to simulate a system over a period of time to evaluate system reliability and availability. Results can be used in the Deep Space Network for initial spares provisioning and system evaluation.

  5. Study of Optimal Perimetric Testing in Children (OPTIC): Feasibility, Reliability and Repeatability of Perimetry in Children

    PubMed Central

    Patel, Dipesh E.; Cumberland, Phillippa M.; Walters, Bronwen C.; Russell-Eggitt, Isabelle; Rahi, Jugnoo S.

    2015-01-01

    Purpose To investigate feasibility, reliability and repeatability of perimetry in children. Methods A prospective, observational study recruiting 154 children aged 5–15 years, without an ophthalmic condition that affects the visual field (controls), identified consecutively between May 2012 and November 2013 from hospital eye clinics. Perimetry was undertaken in a single sitting, with standardised protocols, in a randomised order using the Humphrey static (SITA 24–2 FAST), Goldmann and Octopus kinetic perimeters. Data collected included test duration, subjective experience and test quality (incorporating examiner ratings on comprehension of instructions, fatigue, response to visual and auditory stimuli, concentration and co-operation) to assess feasibility and reliability. Testing was repeated within 6 months to assess repeatability. Results Overall feasibility was very high (Goldmann=96.1%, Octopus=89% and Humphrey=100% completed the tests). Examiner rated reliability was ‘good’ in 125 (81.2%) children for Goldmann, 100 (64.9%) for Octopus and 98 (63.6%) for Humphrey perimetry. Goldmann perimetry was the most reliable method in children under 9 years of age. Reliability improved with increasing age (multinomial logistic regression (Goldmann, Octopus and Humphrey), p<0.001). No significant differences were found for any of the three test strategies when examining initial and follow-up data outputs (Bland-Altman plots, n=43), suggesting good test repeatability, although the sample size may preclude detection of a small learning effect. Conclusions Feasibility and reliability of formal perimetry in children improves with age. By the age of 9 years, all the strategies used here were highly feasible and reliable. Clinical assessment of the visual field is achievable in children as young as 5 years, and should be considered where visual field loss is suspected. Since Goldmann perimetry is the most effective strategy in children aged 5–8 years and this

  6. Identifying a reliable boredom induction.

    PubMed

    Markey, Amanda; Chin, Alycia; Vanepps, Eric M; Loewenstein, George

    2014-08-01

    None of the tasks used to induce boredom have undergone rigorous psychometric validation, which creates potential problems for operational equivalence, comparisons across studies, statistical power, and confounding results. This methodological concern was addressed by testing and comparing the effectiveness of six 5-min. computerized boredom inductions (peg turning, audio, video, signature matching, one-back, and an air traffic control task). The tasks were evaluated using standard criteria for emotion inductions: intensity and discreteness. Intensity, the amount of boredom elicited, was measured using a subset of the Multidimensional State Boredom Scale. Discreteness, the extent to which the task elicited boredom and did not elicit other emotions, was measured using a modification of the Differential Emotion Scale. In both a laboratory setting (Study 1; N = 241) and an online setting with Amazon Mechanical Turk workers (Study 2; N = 416), participants were randomly assigned to one of seven tasks (six boredom tasks or a comparison task, a clip from Planet Earth) before rating their boredom using the MSBS and other emotions using the modified DES. In both studies, each task had significantly higher intensity and discreteness than the comparison task, with moderate to large effect sizes. The peg-turning task outperformed the other tasks in both intensity and discreteness, making it the recommended induction. Identification of reliable and valid boredom inductions and systematic comparison of their relative results should help advance state boredom research.

  7. Identifying a reliable boredom induction.

    PubMed

    Markey, Amanda; Chin, Alycia; Vanepps, Eric M; Loewenstein, George

    2014-08-01

    None of the tasks used to induce boredom have undergone rigorous psychometric validation, which creates potential problems for operational equivalence, comparisons across studies, statistical power, and confounding results. This methodological concern was addressed by testing and comparing the effectiveness of six 5-min. computerized boredom inductions (peg turning, audio, video, signature matching, one-back, and an air traffic control task). The tasks were evaluated using standard criteria for emotion inductions: intensity and discreteness. Intensity, the amount of boredom elicited, was measured using a subset of the Multidimensional State Boredom Scale. Discreteness, the extent to which the task elicited boredom and did not elicit other emotions, was measured using a modification of the Differential Emotion Scale. In both a laboratory setting (Study 1; N = 241) and an online setting with Amazon Mechanical Turk workers (Study 2; N = 416), participants were randomly assigned to one of seven tasks (six boredom tasks or a comparison task, a clip from Planet Earth) before rating their boredom using the MSBS and other emotions using the modified DES. In both studies, each task had significantly higher intensity and discreteness than the comparison task, with moderate to large effect sizes. The peg-turning task outperformed the other tasks in both intensity and discreteness, making it the recommended induction. Identification of reliable and valid boredom inductions and systematic comparison of their relative results should help advance state boredom research. PMID:25153752

  8. Reliable switching in MRAM and multiferroic logic

    NASA Astrophysics Data System (ADS)

    Munira, Kamaram; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha; Chen, Eugene; Ghosh, Avik W.

    2012-02-01

    Low reliable writing in spintronic devices limits their applicability in the automotive and defense industries. Coupling stochastic macromagnetic simulator with quantum transport, we show how greater reliable switching can be achieved in MRAM and multiferroic logic. Using a combination of spin-transfer torque and small applied perpendicular field in MRAM, the error rate can be considerably reduced for a given voltage pulse. In multiferroic logic, strain plays the role of the magnetic field. Information is passed along an array of nanomagnets (NM) (magnetostrictive + piezoelectric layers) through dipole coupling with neighboring NMs. A low voltage applied to the piezoelectric element causes the NM's magnetization to switch to its hard axis. Upon releasing the stress, the magnetization of the NM relaxes to the easy axis, with its final orientation determined by the dipolar coupling with the left NM, thus achieving a low power Bennett clocked computation. In the face of stagnation points along the potential energy landscape, the success rate of the straintronic switching can be controlled with by how fast the stress is removed from the NM. (Funding: DARPA, GRANDIS, NSF-NEB).

  9. 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.

  10. Failure Analysis for Improved Reliability

    NASA Technical Reports Server (NTRS)

    Sood, Bhanu

    2016-01-01

    Outline: Section 1 - What is reliability and root cause? Section 2 - Overview of failure mechanisms. Section 3 - Failure analysis techniques (1. Non destructive analysis techniques, 2. Destructive Analysis, 3. Materials Characterization). Section 4 - Summary and Closure

  11. Reliable Signal Transduction

    NASA Astrophysics Data System (ADS)

    Wollman, Roy

    Stochasticity inherent to biochemical reactions (intrinsic noise) and variability in cellular states (extrinsic noise) degrade information transmitted through signaling networks. We analyzed the ability of temporal signal modulation - that is dynamics - to reduce noise-induced information loss. In the extracellular signal-regulated kinase (ERK), calcium (Ca(2 +)) , and nuclear factor kappa-B (NF- κB) pathways, response dynamics resulted in significantly greater information transmission capacities compared to nondynamic responses. Theoretical analysis demonstrated that signaling dynamics has a key role in overcoming extrinsic noise. Experimental measurements of information transmission in the ERK network under varying signal-to-noise levels confirmed our predictions and showed that signaling dynamics mitigate, and can potentially eliminate, extrinsic noise-induced information loss. By curbing the information-degrading effects of cell-to-cell variability, dynamic responses substantially increase the accuracy of biochemical signaling networks.

  12. High-Reliability Health Care: Getting There from Here

    PubMed Central

    Chassin, Mark R; Loeb, Jerod M

    2013-01-01

    Context Despite serious and widespread efforts to improve the quality of health care, many patients still suffer preventable harm every day. Hospitals find improvement difficult to sustain, and they suffer “project fatigue” because so many problems need attention. No hospitals or health systems have achieved consistent excellence throughout their institutions. High-reliability science is the study of organizations in industries like commercial aviation and nuclear power that operate under hazardous conditions while maintaining safety levels that are far better than those of health care. Adapting and applying the lessons of this science to health care offer the promise of enabling hospitals to reach levels of quality and safety that are comparable to those of the best high-reliability organizations. Methods We combined the Joint Commission's knowledge of health care organizations with knowledge from the published literature and from experts in high-reliability industries and leading safety scholars outside health care. We developed a conceptual and practical framework for assessing hospitals’ readiness for and progress toward high reliability. By iterative testing with hospital leaders, we refined the framework and, for each of its fourteen components, defined stages of maturity through which we believe hospitals must pass to reach high reliability. Findings We discovered that the ways that high-reliability organizations generate and maintain high levels of safety cannot be directly applied to today's hospitals. We defined a series of incremental changes that hospitals should undertake to progress toward high reliability. These changes involve the leadership's commitment to achieving zero patient harm, a fully functional culture of safety throughout the organization, and the widespread deployment of highly effective process improvement tools. Conclusions Hospitals can make substantial progress toward high reliability by undertaking several specific

  13. Accelerator Availability and Reliability Issues

    SciTech Connect

    Steve Suhring

    2003-05-01

    Maintaining reliable machine operations for existing machines as well as planning for future machines' operability present significant challenges to those responsible for system performance and improvement. Changes to machine requirements and beam specifications often reduce overall machine availability in an effort to meet user needs. Accelerator reliability issues from around the world will be presented, followed by a discussion of the major factors influencing machine availability.

  14. MEMS reliability: coming of age

    NASA Astrophysics Data System (ADS)

    Douglass, Michael R.

    2008-02-01

    In today's high-volume semiconductor world, one could easily take reliability for granted. As the MOEMS/MEMS industry continues to establish itself as a viable alternative to conventional manufacturing in the macro world, reliability can be of high concern. Currently, there are several emerging market opportunities in which MOEMS/MEMS is gaining a foothold. Markets such as mobile media, consumer electronics, biomedical devices, and homeland security are all showing great interest in microfabricated products. At the same time, these markets are among the most demanding when it comes to reliability assurance. To be successful, each company developing a MOEMS/MEMS device must consider reliability on an equal footing with cost, performance and manufacturability. What can this maturing industry learn from the successful development of DLP technology, air bag accelerometers and inkjet printheads? This paper discusses some basic reliability principles which any MOEMS/MEMS device development must use. Examples from the commercially successful and highly reliable Digital Micromirror Device complement the discussion.

  15. On software implementation of reliability of unmanned ground vehicles

    NASA Astrophysics Data System (ADS)

    Dixit, Arati M.; Saab, Kassem; Singh, Harpreet; Mustapha, Adam; Gerhart, Grant R.

    2009-05-01

    Critical role of unmanned intelligent ground vehicles is evident from variety of defense applications. Fuzzy Reliability predicts reliability of the convoy of unmanned vehicles represented as a communication network with nodes as vehicle station and branches as path between the stations. Fuzzy Reliability affirms the performance of the system. Fuzzy reliability of a convoy of vehicles is the result of Fuzzy and Boolean approaches. The node and branch reliability is calculated using the Fuzzy approach. The terminal reliability is calculated using Boolean algebra. Software implementation of the fuzzy reliability is successfully done. To improve the performance evaluation of the convoy, node failure i.e. failure of convoy station is also taken into consideration. Depending upon the reliability predicted a commander can take appropriate decision in the battlefield. Proposed algorithm determines all paths from source to destination and Boolean expressions are formed. A non-overlapping simplification is obtained and further transformed into mathematical expression, where reliability values are substituted. The results of design, implementation and simulation of the reliability of convoy of unmanned vehicles are given. It is hoped that the proposed algorithm and its implementation will be useful for sensor network in general and graph of unmanned vehicles in particular.

  16. Utility Static Generation Reliability

    1993-03-05

    PICES (Probabilistic Investigation of Capacity and Energy Shortages) was developed for estimating an electric utility''s expected frequency and duration of capacity deficiencies on a daily on and off-peak basis. In addition to the system loss-of-load probability (LOLP) and loss-of-load expectation (LOLE) indices, PICES calculates the expected frequency and duration of system capacity deficiencies and the probability, expectation, and expected frequency and duration of a range of system reserve margin states. Results are aggregated and printedmore » on a weekly, monthly, or annual basis. The program employs hourly load data and either the two-state (on/off) or a more sophisticated three-state (on/partially on/fully off) generating unit representation. Unit maintenance schedules are determined on a weekly, levelized reserve margin basis. In addition to the 8760-hour annual load record, the user provides the following information for each unit: plant capacity, annual maintenance requirement, two or three-state unit failure and repair rates, and for three-state models, the partial state capacity deficiency. PICES can also supply default failure and repair rate values, based on the Edison Electric Institute''s 1979 Report on Equipment Availability for the Ten-Year Period 1968 Through 1977, for many common plant types. Multi-year analysis can be performed by specifying as input data the annual peak load growth rates and plant addition and retirement schedules for each year in the study.« less

  17. Reliability of the North Star Ambulatory Assessment in a multicentric setting.

    PubMed

    Mazzone, E S; Messina, S; Vasco, G; Main, M; Eagle, M; D'Amico, A; Doglio, L; Politano, L; Cavallaro, F; Frosini, S; Bello, L; Magri, F; Corlatti, A; Zucchini, E; Brancalion, B; Rossi, F; Ferretti, M; Motta, M G; Cecio, M R; Berardinelli, A; Alfieri, P; Mongini, T; Pini, A; Astrea, G; Battini, R; Comi, G; Pegoraro, E; Morandi, L; Pane, M; Angelini, C; Bruno, C; Villanova, M; Vita, G; Donati, M A; Bertini, E; Mercuri, E

    2009-07-01

    The aim of this study was to investigate the suitability of the North Star Ambulatory Assessment as a possible outcome measure in multicentric clinical trials. More specifically we wished to investigate the level of training needed for achieving a good interobserver reliability in a multicentric setting. The scale was specifically designed for ambulant children with Duchenne Muscular Dystrophy and includes 17 items that are relevant for this cohort. Thirteen Italian centers participated in the study. In the first phase of the study we provided two training videos and an example of the scale performed on a child. After the first session of training, all the 13 examiners were asked to send a video with an assessment performed in their centre and to score all the videos collected. There were no difficulties in performing the items and in obtaining adequate videos with a hand held camera but the results showed a poor interobserver reliability (<.5). After a second training session with review and discussion of the videos previously scored, the same examiners were asked to score three new videos. The results of this session had an excellent interobserver reliability (.995). The level of agreement was maintained even when the same videos were rescored after a month, showing a significant intra-observer reliability (.95). Our results suggest that the NSAA is a test that can be easily performed, completed in 10 min and can be used in a multicentric setting, providing that adequate training is administered.

  18. Asymmetric programming: a highly reliable metadata allocation strategy for MLC NAND flash memory-based sensor systems.

    PubMed

    Huang, Min; Liu, Zhaoqing; Qiao, Liyan

    2014-01-01

    While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme.

  19. Asymmetric programming: a highly reliable metadata allocation strategy for MLC NAND flash memory-based sensor systems.

    PubMed

    Huang, Min; Liu, Zhaoqing; Qiao, Liyan

    2014-01-01

    While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme. PMID:25310473

  20. Reliability prediction of corroding pipelines

    SciTech Connect

    Strutt, J.E.; Allsopp, K.; Newman, D.; Trille, C.

    1996-12-01

    Recent data collection studies relating to loss of containment of pipeline and risers indicate that corrosion is now the dominant failure mode for steel pipelines in the North Sea area. As the North Sea pipeline infrastructure ages, it is expected that the proportion of pipelines failing by corrosion will increase further and this raises the question of the relationship between probability of pipeline corrosion failure and the reliability of the corrosion control and monitoring systems used by operators to prevent corrosion failures. This paper describes a methodology for predicting the probability of corrosion failure of a specific submarine pipeline or riser system. The paper illustrates how the model can be used to predict the safe life of a pipeline, given knowledge of the underlying corrosion behavior and corrosion control system and how the time to failure can be updated in the light of inspection and monitoring results enabling inspection policy to be evaluated for its impact on risk. The paper also shows how different assumptions concerning the underlying cause of failure influences the estimation of the probability of failure.

  1. Evaluation of MHTGR fuel reliability

    SciTech Connect

    Wichner, R.P.; Barthold, W.P.

    1992-07-01

    Modular High-Temperature Gas-Cooled Reactor (MHTGR) concepts that house the reactor vessel in a tight but unsealed reactor building place heightened importance on the reliability of the fuel particle coatings as fission product barriers. Though accident consequence analyses continue to show favorable results, the increased dependence on one type of barrier, in addition to a number of other factors, has caused the Nuclear Regulatory Commission (NRC) to consider conservative assumptions regarding fuel behavior. For this purpose, the concept termed ``weak fuel`` has been proposed on an interim basis. ``Weak fuel`` is a penalty imposed on consequence analyses whereby the fuel is assumed to respond less favorably to environmental conditions than predicted by behavioral models. The rationale for adopting this penalty, as well as conditions that would permit its reduction or elimination, are examined in this report. The evaluation includes an examination of possible fuel-manufacturing defects, quality-control procedures for defect detection, and the mechanisms by which fuel defects may lead to failure.

  2. Reliability analysis of wastewater treatment plants.

    PubMed

    Oliveira, Sílvia C; Von Sperling, Marcos

    2008-02-01

    This article presents a reliability analysis of 166 full-scale wastewater treatment plants operating in Brazil. Six different processes have been investigated, comprising septic tank+anaerobic filter, facultative pond, anaerobic pond+facultative pond, activated sludge, upflow anaerobic sludge blanket (UASB) reactors alone and UASB reactors followed by post-treatment. A methodology developed by Niku et al. [1979. Performance of activated sludge process and reliability-based design. J. Water Pollut. Control Assoc., 51(12), 2841-2857] is used for determining the coefficients of reliability (COR), in terms of the compliance of effluent biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP) and fecal or thermotolerant coliforms (FC) with discharge standards. The design concentrations necessary to meet the prevailing discharge standards and the expected compliance percentages have been calculated from the COR obtained. The results showed that few plants, under the observed operating conditions, would be able to present reliable performances considering the compliance with the analyzed standards. The article also discusses the importance of understanding the lognormal behavior of the data in setting up discharge standards, in interpreting monitoring results and compliance with the legislation. PMID:17897694

  3. Reliability analysis of wastewater treatment plants.

    PubMed

    Oliveira, Sílvia C; Von Sperling, Marcos

    2008-02-01

    This article presents a reliability analysis of 166 full-scale wastewater treatment plants operating in Brazil. Six different processes have been investigated, comprising septic tank+anaerobic filter, facultative pond, anaerobic pond+facultative pond, activated sludge, upflow anaerobic sludge blanket (UASB) reactors alone and UASB reactors followed by post-treatment. A methodology developed by Niku et al. [1979. Performance of activated sludge process and reliability-based design. J. Water Pollut. Control Assoc., 51(12), 2841-2857] is used for determining the coefficients of reliability (COR), in terms of the compliance of effluent biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP) and fecal or thermotolerant coliforms (FC) with discharge standards. The design concentrations necessary to meet the prevailing discharge standards and the expected compliance percentages have been calculated from the COR obtained. The results showed that few plants, under the observed operating conditions, would be able to present reliable performances considering the compliance with the analyzed standards. The article also discusses the importance of understanding the lognormal behavior of the data in setting up discharge standards, in interpreting monitoring results and compliance with the legislation.

  4. Achieving closure at Fernald

    SciTech Connect

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  5. The 747 primary flight control systems reliability and maintenance study

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The major operational characteristics of the 747 Primary Flight Control Systems (PFCS) are described. Results of reliability analysis for separate control functions are presented. The analysis makes use of a NASA computer program which calculates reliability of redundant systems. Costs for maintaining the 747 PFCS in airline service are assessed. The reliabilities and cost will provide a baseline for use in trade studies of future flight control system design.

  6. [Study of the relationship between human quality and reliability].

    PubMed

    Long, S; Wang, C; Wang, L i; Yuan, J; Liu, H; Jiao, X

    1997-02-01

    To clarify the relationship between human quality and reliability, 1925 experiments in 20 subjects were carried out to study the relationship between disposition character, digital memory, graphic memory, multi-reaction time and education level and simulated aircraft operation. Meanwhile, effects of task difficulty and enviromental factor on human reliability were also studied. The results showed that human quality can be predicted and evaluated through experimental methods. The better the human quality, the higher the human reliability. PMID:11539889

  7. Reliability issues in power and ground on submicron circuits

    SciTech Connect

    Tuan, J.F.; Young, T.K.

    1995-12-31

    The reliability of the power supply network is becoming an important issue for IC designers as circuit sizes increase. The reliability problems in power networks are electromigration, voltage drop, and ground bounce. RailMill is an integrated environment that addresses the power network reliability problems. RailMill covers four important aspects in power network analysis: accurate extraction of power networks, accurate simulation of transistor circuits, accurate simulation of power networks and layout display of circuit and simulation results.

  8. Planning Adult Literacy Education to Achieve Results in Nigeria.

    ERIC Educational Resources Information Center

    Anukam, I. L.

    1988-01-01

    Mass illiteracy is recognized by many Nigerians as a debilitating malady that must be addressed if the nation is to make developmental headway. The Mass Literacy Campaign, launched to attempt to reduce illiteracy, has not made a significant impact because of poor planning, poor funding, poor programs, and inadequate staff. (JOW)

  9. Busted Butte: Achieving the Objectives and Numerical Modeling Results

    SciTech Connect

    W.E. Soll; M. Kearney; P. Stauffer; P. Tseng; H.J. Turin; Z. Lu

    2002-10-07

    The Unsaturated Zone Transport Test (UZTT) at Busted Butte is a mesoscale field/laboratory/modeling investigation designed to address uncertainties associated with flow and transport in the UZ site-process models for Yucca Mountain. The UZTT test facility is located approximately 8 km southeast of the potential Yucca Mountain repository area. The UZTT was designed in two phases, to address five specific objectives in the UZ: the effect of heterogeneities, flow and transport (F&T) behavior at permeability contrast boundaries, migration of colloids , transport models of sorbing tracers, and scaling issues in moving from laboratory scale to field scale. Phase 1A was designed to assess the influence of permeability contrast boundaries in the hydrologic Calico Hills. Visualization of fluorescein movement , mineback rock analyses, and comparison with numerical models demonstrated that F&T are capillary dominated with permeability contrast boundaries distorting the capillary flow. Phase 1B was designed to assess the influence of fractures on F&T and colloid movement. The injector in Phase 1B was located at a fracture, while the collector, 30 cm below, was placed at what was assumed to be the same fracture. Numerical simulations of nonreactive (Br) and reactive (Li) tracers show the experimental data are best explained by a combination of molecular diffusion and advective flux. For Phase 2, a numerical model with homogeneous unit descriptions was able to qualitatively capture the general characteristics of the system. Numerical simulations and field observations revealed a capillary dominated flow field. Although the tracers showed heterogeneity in the test block, simulation using heterogeneous fields did not significantly improve the data fit over homogeneous field simulations. In terms of scaling, simulations of field tracer data indicate a hydraulic conductivity two orders of magnitude higher than measured in the laboratory. Simulations of Li, a weakly sorbing tracer, indicate less retardation than predicted from laboratory batch measurements.

  10. Master/slave clock arrangement for providing reliable clock signal

    NASA Technical Reports Server (NTRS)

    Abbey, Duane L. (Inventor)

    1977-01-01

    The outputs of two like frequency oscillators are combined to form a single reliable clock signal, with one oscillator functioning as a slave under the control of the other to achieve phase coincidence when the master is operative and in a free-running mode when the master is inoperative so that failure of either oscillator produces no effect on the clock signal.

  11. Test–Retest Reliability of the Genetics and Genomics in Nursing Practice Survey Instrument

    PubMed Central

    Calzone, Kathleen A.; Culp, Stacey; Jenkins, Jean; Caskey, Sarah; Edwards, Pamela B.; Fuchs, Mary Ann; Reints, Amber; Stange, Brita; Questad, Janice; Badzek, Laurie

    2016-01-01

    Background and Purpose Assessment of nursing genomic competency is critical given increasing genomic applications to health care. The study aims were to determine the test–retest reliability of the Genetics and Genomics in Nursing Practice Survey (GGNPS), which measures this competency, and to revise the survey accordingly. Methods Registered nurses (n = 232) working at 2 Magnet-designated hospitals participating in a multiinstitutional genomic competency study completed the GGNPS. Cohen’s kappa and weighted kappa were used to measure the agreement of item responses between Time 1 and Time 2. Survey items were revised based on the results. Results Mean agreement for the instrument was 0.407 (range = 0.150–1.000). Moderate agreement or higher was achieved in 39% of the items. Conclusions GGNPS test–retest reliability was not optimal, and the instrument was refined based on the study findings. Further testing of the revised instrument is planned to assess the instrument performance. PMID:27103245

  12. Flow monitor reliability design criteria for thermal mass flow measurement systems

    SciTech Connect

    Groce, P.J.

    1995-12-31

    Implementation of Title IV of the Clean Air Act greatly expanded the market of mass flow measurement in utility flue gas ducts and stacks. Lessons learned from recent experience in this demanding application resulted in the rapid evolution of equipment designed to ensure accuracy, reliability and ease of maintenance. Thermal mass flow measurement, one of three accepted methods of mass flow measurement, has proven to be an accurate and reliable means of achieving dependable flow data. Aside from system accuracy and repeatability, on-line time appears to be the critical performance factor for any mass flow measurement system. This paper addresses the major design features that have resulted in maximum on-line time and conformance with compliance plans.

  13. Brain Wave Analysis and School Achievement.

    ERIC Educational Resources Information Center

    Wilson, Barry; And Others

    The Brain Wave Analyzer (BWA Ertl 02) was used to measure the brain potentials of 110 public school children. Resulting scores were correlated with concurrent measures of school achievement. Results indicate that certain brain wave scores have relatively low correlations with school achievement compared to traditional intelligence measures but may…

  14. Crystalline-silicon reliability lessons for thin-film modules

    NASA Astrophysics Data System (ADS)

    Ross, R. G., Jr.

    1985-10-01

    The reliability of crystalline silicon modules has been brought to a high level with lifetimes approaching 20 years, and excellent industry credibility and user satisfaction. The transition from crystalline modules to thin film modules is comparable to the transition from discrete transistors to integrated circuits. New cell materials and monolithic structures will require new device processing techniques, but the package function and design will evolve to a lesser extent. Although there will be new encapsulants optimized to take advantage of the mechanical flexibility and low temperature processing features of thin films, the reliability and life degradation stresses and mechanisms will remain mostly unchanged. Key reliability technologies in common between crystalline and thin film modules include hot spot heating, galvanic and electrochemical corrosion, hail impact stresses, glass breakage, mechanical fatigue, photothermal degradation of encapsulants, operating temperature, moisture sorption, circuit design strategies, product safety issues, and the process required to achieve a reliable product from a laboratory prototype.

  15. Reliability model of a monopropellant auxiliary propulsion system

    NASA Technical Reports Server (NTRS)

    Greenberg, J. S.

    1971-01-01

    A mathematical model and associated computer code has been developed which computes the reliability of a monopropellant blowdown hydrazine spacecraft auxiliary propulsion system as a function of time. The propulsion system is used to adjust or modify the spacecraft orbit over an extended period of time. The multiple orbit corrections are the multiple objectives which the auxiliary propulsion system is designed to achieve. Thus the reliability model computes the probability of successfully accomplishing each of the desired orbit corrections. To accomplish this, the reliability model interfaces with a computer code that models the performance of a blowdown (unregulated) monopropellant auxiliary propulsion system. The computer code acts as a performance model and as such gives an accurate time history of the system operating parameters. The basic timing and status information is passed on to and utilized by the reliability model which establishes the probability of successfully accomplishing the orbit corrections.

  16. Crystalline-silicon reliability lessons for thin-film modules

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1985-01-01

    The reliability of crystalline silicon modules has been brought to a high level with lifetimes approaching 20 years, and excellent industry credibility and user satisfaction. The transition from crystalline modules to thin film modules is comparable to the transition from discrete transistors to integrated circuits. New cell materials and monolithic structures will require new device processing techniques, but the package function and design will evolve to a lesser extent. Although there will be new encapsulants optimized to take advantage of the mechanical flexibility and low temperature processing features of thin films, the reliability and life degradation stresses and mechanisms will remain mostly unchanged. Key reliability technologies in common between crystalline and thin film modules include hot spot heating, galvanic and electrochemical corrosion, hail impact stresses, glass breakage, mechanical fatigue, photothermal degradation of encapsulants, operating temperature, moisture sorption, circuit design strategies, product safety issues, and the process required to achieve a reliable product from a laboratory prototype.

  17. Achievement Goals and Achievement Emotions: A Meta-Analysis

    ERIC Educational Resources Information Center

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

  18. Measurement, estimation, and prediction of software reliability

    NASA Technical Reports Server (NTRS)

    Hecht, H.

    1977-01-01

    Quantitative indices of software reliability are defined, and application of three important indices is indicated: (1) reliability measurement, (2) reliability estimation, and (3) reliability prediction. State of the art techniques for each of these procedures are presented together with considerations of data acquisition. Failure classifications and other documentation for comprehensive software reliability evaluation are described.

  19. Availability and End-to-end Reliability in Low Duty Cycle Multihop Wireless Sensor Networks

    PubMed Central

    Suhonen, Jukka; Hämäläinen, Timo D.; Hännikäinen, Marko

    2009-01-01

    A wireless sensor network (WSN) is an ad-hoc technology that may even consist of thousands of nodes, which necessitates autonomic, self-organizing and multihop operations. A typical WSN node is battery powered, which makes the network lifetime the primary concern. The highest energy efficiency is achieved with low duty cycle operation, however, this alone is not enough. WSNs are deployed for different uses, each requiring acceptable Quality of Service (QoS). Due to the unique characteristics of WSNs, such as dynamic wireless multihop routing and resource constraints, the legacy QoS metrics are not feasible as such. We give a new definition to measure and implement QoS in low duty cycle WSNs, namely availability and reliability. Then, we analyze the effect of duty cycling for reaching the availability and reliability. The results are obtained by simulations with ZigBee and proprietary TUTWSN protocols. Based on the results, we also propose a data forwarding algorithm suitable for resource constrained WSNs that guarantees end-to-end reliability while adding a small overhead that is relative to the packet error rate (PER). The forwarding algorithm guarantees reliability up to 30% PER. PMID:22574002

  20. Working Group summary reports from the Advanced Photon Source reliability workshop

    SciTech Connect

    Not Available

    1992-05-01

    A workshop was held at APS to address reliability goals for accelerator systems. Seventy-one individuals participated in the workshop, including 30 from other institutions. The goals of the workshop were to: (1) Give attendees an introduction to the basic concepts of reliability analysis. (2) Exchange information on operating experience at existing accelerator facilities and strategies for achieving reliability at facilities under design or in construction. (3) Discuss reliability goals for APS and the means of their achievement. This report contains the working group summary report an APS`s following systems: RF Systems; Power Supplies; Magnet Systems; Interlock and Diagnostics; and Vacuum Systems.