WorldWideScience

Sample records for reliability growth implications

  1. AMSAA Reliability Growth Guide

    National Research Council Canada - National Science Library

    Broemm, William

    2000-01-01

    ... has developed reliability growth methodology for all phases of the process, from planning to tracking to projection. The report presents this methodology and associated reliability growth concepts.

  2. Prime implicants in dynamic reliability analysis

    International Nuclear Information System (INIS)

    Tyrväinen, Tero

    2016-01-01

    This paper develops an improved definition of a prime implicant for the needs of dynamic reliability analysis. Reliability analyses often aim to identify minimal cut sets or prime implicants, which are minimal conditions that cause an undesired top event, such as a system's failure. Dynamic reliability analysis methods take the time-dependent behaviour of a system into account. This means that the state of a component can change in the analysed time frame and prime implicants can include the failure of a component at different time points. There can also be dynamic constraints on a component's behaviour. For example, a component can be non-repairable in the given time frame. If a non-repairable component needs to be failed at a certain time point to cause the top event, we consider that the condition that it is failed at the latest possible time point is minimal, and the condition in which it fails earlier non-minimal. The traditional definition of a prime implicant does not account for this type of time-related minimality. In this paper, a new definition is introduced and illustrated using a dynamic flowgraph methodology model. - Highlights: • A new definition of a prime implicant is developed for dynamic reliability analysis. • The new definition takes time-related minimality into account. • The new definition is needed in dynamic flowgraph methodology. • Results can be represented by a smaller number of prime implicants.

  3. Reliability Growth in Space Life Support Systems

    Science.gov (United States)

    Jones, Harry W.

    2014-01-01

    A hardware system's failure rate often increases over time due to wear and aging, but not always. Some systems instead show reliability growth, a decreasing failure rate with time, due to effective failure analysis and remedial hardware upgrades. Reliability grows when failure causes are removed by improved design. A mathematical reliability growth model allows the reliability growth rate to be computed from the failure data. The space shuttle was extensively maintained, refurbished, and upgraded after each flight and it experienced significant reliability growth during its operational life. In contrast, the International Space Station (ISS) is much more difficult to maintain and upgrade and its failure rate has been constant over time. The ISS Carbon Dioxide Removal Assembly (CDRA) reliability has slightly decreased. Failures on ISS and with the ISS CDRA continue to be a challenge.

  4. Ethical Implications of Validity-vs.-Reliability Trade-Offs in Educational Research

    Science.gov (United States)

    Fendler, Lynn

    2016-01-01

    In educational research that calls itself empirical, the relationship between validity and reliability is that of trade-off: the stronger the bases for validity, the weaker the bases for reliability (and vice versa). Validity and reliability are widely regarded as basic criteria for evaluating research; however, there are ethical implications of…

  5. Inclusive growth versus pro-poor growth: Implications for tourism development

    NARCIS (Netherlands)

    Bakker, Martine; Messerli, H.R.

    2017-01-01

    Inclusive growth and pro-poor growth are terms embraced but not fully understood in the tourism community. This paper discusses the main concepts of inclusive growth and their implication for tourism development across the developing world. Is inclusive growth simply another term for pro-poor in

  6. An analytical framework for reliability growth of one-shot systems

    International Nuclear Information System (INIS)

    Hall, J. Brian; Mosleh, Ali

    2008-01-01

    In this paper, we introduce a new reliability growth methodology for one-shot systems that is applicable to the case where all corrective actions are implemented at the end of the current test phase. The methodology consists of four model equations for assessing: expected reliability, the expected number of failure modes observed in testing, the expected probability of discovering new failure modes, and the expected portion of system unreliability associated with repeat failure modes. These model equations provide an analytical framework for which reliability practitioners can estimate reliability improvement, address goodness-of-fit concerns, quantify programmatic risk, and assess reliability maturity of one-shot systems. A numerical example is given to illustrate the value and utility of the presented approach. This methodology is useful to program managers and reliability practitioners interested in applying the techniques above in their reliability growth program

  7. Possibilities and limitations of applying software reliability growth models to safety-critical software

    International Nuclear Information System (INIS)

    Kim, Man Cheol; Jang, Seung Cheol; Ha, Jae Joo

    2007-01-01

    It is generally known that software reliability growth models such as the Jelinski-Moranda model and the Goel-Okumoto's Non-Homogeneous Poisson Process (NHPP) model cannot be applied to safety-critical software due to a lack of software failure data. In this paper, by applying two of the most widely known software reliability growth models to sample software failure data, we demonstrate the possibility of using the software reliability growth models to prove the high reliability of safety-critical software. The high sensitivity of a piece of software's reliability to software failure data, as well as a lack of sufficient software failure data, is also identified as a possible limitation when applying the software reliability growth models to safety-critical software

  8. Procedure for Application of Software Reliability Growth Models to NPP PSA

    International Nuclear Information System (INIS)

    Son, Han Seong; Kang, Hyun Gook; Chang, Seung Cheol

    2009-01-01

    As the use of software increases at nuclear power plants (NPPs), the necessity for including software reliability and/or safety into the NPP Probabilistic Safety Assessment (PSA) rises. This work proposes an application procedure of software reliability growth models (RGMs), which are most widely used to quantify software reliability, to NPP PSA. Through the proposed procedure, it can be determined if a software reliability growth model can be applied to the NPP PSA before its real application. The procedure proposed in this work is expected to be very helpful for incorporating software into NPP PSA

  9. Stochastic Differential Equation-Based Flexible Software Reliability Growth Model

    Directory of Open Access Journals (Sweden)

    P. K. Kapur

    2009-01-01

    Full Text Available Several software reliability growth models (SRGMs have been developed by software developers in tracking and measuring the growth of reliability. As the size of software system is large and the number of faults detected during the testing phase becomes large, so the change of the number of faults that are detected and removed through each debugging becomes sufficiently small compared with the initial fault content at the beginning of the testing phase. In such a situation, we can model the software fault detection process as a stochastic process with continuous state space. In this paper, we propose a new software reliability growth model based on Itô type of stochastic differential equation. We consider an SDE-based generalized Erlang model with logistic error detection function. The model is estimated and validated on real-life data sets cited in literature to show its flexibility. The proposed model integrated with the concept of stochastic differential equation performs comparatively better than the existing NHPP-based models.

  10. Reliability implications for commercial Plowshare applications

    Energy Technology Data Exchange (ETDEWEB)

    Brumleve, T D [Plowshare Systems Research Division, Sandia Laboratories, Livermore, CA (United States)

    1970-05-15

    Based on the premise that there will always be a finite chance of a Plowshare project failure, the implications of such a failure are examined. It is suggested that the optimum reliability level will not necessarily be the highest attainable, but rather that which results in minimum average project cost. The type of performance guarantee that the U. S. should provide for nuclear explosive services, the determination of nuclear yield, courses of action to take in the event of failure, and methods to offset remedial costs are discussed. (author)

  11. Reliability implications for commercial Plowshare applications

    International Nuclear Information System (INIS)

    Brumleve, T.D.

    1970-01-01

    Based on the premise that there will always be a finite chance of a Plowshare project failure, the implications of such a failure are examined. It is suggested that the optimum reliability level will not necessarily be the highest attainable, but rather that which results in minimum average project cost. The type of performance guarantee that the U. S. should provide for nuclear explosive services, the determination of nuclear yield, courses of action to take in the event of failure, and methods to offset remedial costs are discussed. (author)

  12. The use of Career Growth Scale in Chinese nurses: Validity and reliability

    OpenAIRE

    Jingying Liu; Jipeng Yang; Yanhui Liu; Yang Yang; Hongfu Zhang

    2015-01-01

    Purpose: To test the validity and reliability of a modified Career Growth Scale (CGS) to assess nurse career growth. Method: A cross-sectional design was used to analyze the use of the CGS to survey 600 full-time registered nurses from Grade A hospitals in Tianjin. Results: A modified scale we called Career Growth of Nurse Scale (CGNS) is acceptable, valid, and reliable for the evaluation of nurse career growth in Chinese hospitals. This scale measured three main factors (career goal, c...

  13. Possibilities and Limitations of Applying Software Reliability Growth Models to Safety- Critical Software

    International Nuclear Information System (INIS)

    Kim, Man Cheol; Jang, Seung Cheol; Ha, Jae Joo

    2006-01-01

    As digital systems are gradually introduced to nuclear power plants (NPPs), the need of quantitatively analyzing the reliability of the digital systems is also increasing. Kang and Sung identified (1) software reliability, (2) common-cause failures (CCFs), and (3) fault coverage as the three most critical factors in the reliability analysis of digital systems. For the estimation of the safety-critical software (the software that is used in safety-critical digital systems), the use of Bayesian Belief Networks (BBNs) seems to be most widely used. The use of BBNs in reliability estimation of safety-critical software is basically a process of indirectly assigning a reliability based on various observed information and experts' opinions. When software testing results or software failure histories are available, we can use a process of directly estimating the reliability of the software using various software reliability growth models such as Jelinski- Moranda model and Goel-Okumoto's nonhomogeneous Poisson process (NHPP) model. Even though it is generally known that software reliability growth models cannot be applied to safety-critical software due to small number of expected failure data from the testing of safety-critical software, we try to find possibilities and corresponding limitations of applying software reliability growth models to safety critical software

  14. Stochastic process corrosion growth models for pipeline reliability

    International Nuclear Information System (INIS)

    Bazán, Felipe Alexander Vargas; Beck, André Teófilo

    2013-01-01

    Highlights: •Novel non-linear stochastic process corrosion growth model is proposed. •Corrosion rate modeled as random Poisson pulses. •Time to corrosion initiation and inherent time-variability properly represented. •Continuous corrosion growth histories obtained. •Model is shown to precisely fit actual corrosion data at two time points. -- Abstract: Linear random variable corrosion models are extensively employed in reliability analysis of pipelines. However, linear models grossly neglect well-known characteristics of the corrosion process. Herein, a non-linear model is proposed, where corrosion rate is represented as a Poisson square wave process. The resulting model represents inherent time-variability of corrosion growth, produces continuous growth and leads to mean growth at less-than-one power of time. Different corrosion models are adjusted to the same set of actual corrosion data for two inspections. The proposed non-linear random process corrosion growth model leads to the best fit to the data, while better representing problem physics

  15. Software reliability growth model for safety systems of nuclear reactor

    International Nuclear Information System (INIS)

    Thirugnana Murthy, D.; Murali, N.; Sridevi, T.; Satya Murty, S.A.V.; Velusamy, K.

    2014-01-01

    The demand for complex software systems has increased more rapidly than the ability to design, implement, test, and maintain them, and the reliability of software systems has become a major concern for our, modern society.Software failures have impaired several high visibility programs in space, telecommunications, defense and health industries. Besides the costs involved, it setback the projects. The ways of quantifying it and using it for improvement and control of the software development and maintenance process. This paper discusses need for systematic approaches for measuring and assuring software reliability which is a major share of project development resources. It covers the reliability models with the concern on 'Reliability Growth'. It includes data collection on reliability, statistical estimation and prediction, metrics and attributes of product architecture, design, software development, and the operational environment. Besides its use for operational decisions like deployment, it includes guiding software architecture, development, testing and verification and validation. (author)

  16. Implications of population growth for Nigeria's development | Fan ...

    African Journals Online (AJOL)

    Nigeria's population that was 16 million in 1911 is about 140 million today. Attention invariably turns to the implications of this growth to the qualities of life for her inhabitants. The paper notes that high birth rate, low death rate and migration are the sources of the high population growth in Nigeria. The population then ...

  17. Growth and Puberty in Obese Children and Implications of Body Composition

    Directory of Open Access Journals (Sweden)

    Sochung Chung

    2017-12-01

    Full Text Available Childhood obesity is a major public health concern throughout the world. Nutrition, energy balance and hormones interplay in growth and pubertal development regulation. Frequently overweight and obese children are taller for their age and sex and tend to mature earlier than lean children. The increased leptin and sex hormone levels seen in obese children with excessive adiposity may be implicated in accelerated pubertal growth and accelerated epiphyseal growth plate maturation. Efforts to detect the impact of obesity in children are needed to prevent metabolic and cardiovascular disease in later life. This review aims to cover the process of growth in obese children and implications of body composition on growth and pubertal development and introduce the use of body composition charts in clinical practice.

  18. A study of software reliability growth from the perspective of learning effects

    International Nuclear Information System (INIS)

    Chiu, K.-C.; Huang, Y.-S.; Lee, T.-Z.

    2008-01-01

    For the last three decades, reliability growth has been studied to predict software reliability in the testing/debugging phase. Most of the models developed were based on the non-homogeneous Poisson process (NHPP), and S-shaped type or exponential-shaped type of behavior is usually assumed. Unfortunately, such models may be suitable only for particular software failure data, thus narrowing the scope of applications. Therefore, from the perspective of learning effects that can influence the process of software reliability growth, we considered that efficiency in testing/debugging concerned not only the ability of the testing staff but also the learning effect that comes from inspecting the testing/debugging codes. The proposed approach can reasonably describe the S-shaped and exponential-shaped types of behaviors simultaneously, and the results in the experiment show good fit. A comparative analysis to evaluate the effectiveness for the proposed model and other software failure models was also performed. Finally, an optimal software release policy is suggested

  19. Cervical vertebral maturation method and mandibular growth peak: a longitudinal study of diagnostic reliability.

    Science.gov (United States)

    Perinetti, Giuseppe; Primozic, Jasmina; Sharma, Bhavna; Cioffi, Iacopo; Contardo, Luca

    2018-03-28

    The capability of the cervical vertebral maturation (CVM) method in the identification of the mandibular growth peak on an individual basis remains undetermined. The diagnostic reliability of the six-stage CVM method in the identification of the mandibular growth peak was thus investigated. From the files of the Oregon and Burlington Growth Studies (data obtained between early 1950s and middle 1970s), 50 subjects (26 females, 24 males) with at least seven annual lateral cephalograms taken from 9 to 16 years were identified. Cervical vertebral maturation was assessed according to the CVM code staging system, and mandibular growth was defined as annual increments in Co-Gn distance. A diagnostic reliability analysis was carried out to establish the capability of the circumpubertal CVM stages 2, 3, and 4 in the identification of the imminent mandibular growth peak. Variable durations of each of the CVM stages 2, 3, and 4 were seen. The overall diagnostic accuracy values for the CVM stages 2, 3, and 4 were 0.70, 0.76, and 0.77, respectively. These low values appeared to be due to false positive cases. Secular trends in conjunction with the use of a discrete staging system. In most of the Burlington Growth Study sample, the lateral head film at age 15 was missing. None of the CVM stages 2, 3, and 4 reached a satisfactorily diagnostic reliability in the identification of imminent mandibular growth peak.

  20. Estimating the Parameters of Software Reliability Growth Models Using the Grey Wolf Optimization Algorithm

    OpenAIRE

    Alaa F. Sheta; Amal Abdel-Raouf

    2016-01-01

    In this age of technology, building quality software is essential to competing in the business market. One of the major principles required for any quality and business software product for value fulfillment is reliability. Estimating software reliability early during the software development life cycle saves time and money as it prevents spending larger sums fixing a defective software product after deployment. The Software Reliability Growth Model (SRGM) can be used to predict the number of...

  1. A mechanism of extreme growth and reliable signaling in sexually selected ornaments and weapons.

    Science.gov (United States)

    Emlen, Douglas J; Warren, Ian A; Johns, Annika; Dworkin, Ian; Lavine, Laura Corley

    2012-08-17

    Many male animals wield ornaments or weapons of exaggerated proportions. We propose that increased cellular sensitivity to signaling through the insulin/insulin-like growth factor (IGF) pathway may be responsible for the extreme growth of these structures. We document how rhinoceros beetle horns, a sexually selected weapon, are more sensitive to nutrition and more responsive to perturbation of the insulin/IGF pathway than other body structures. We then illustrate how enhanced sensitivity to insulin/IGF signaling in a growing ornament or weapon would cause heightened condition sensitivity and increased variability in expression among individuals--critical properties of reliable signals of male quality. The possibility that reliable signaling arises as a by-product of the growth mechanism may explain why trait exaggeration has evolved so many different times in the context of sexual selection.

  2. Sintered tantalum carbide coatings on graphite substrates: Highly reliable protective coatings for bulk and epitaxial growth

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Daisuke; Suzumura, Akitoshi; Shigetoh, Keisuke [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

    2015-02-23

    Highly reliable low-cost protective coatings have been sought after for use in crucibles and susceptors for bulk and epitaxial film growth processes involving wide bandgap materials. Here, we propose a production technique for ultra-thick (50–200 μmt) tantalum carbide (TaC) protective coatings on graphite substrates, which consists of TaC slurry application and subsequent sintering processes, i.e., a wet ceramic process. Structural analysis of the sintered TaC layers indicated that they have a dense granular structure containing coarse grain with sizes of 10–50 μm. Furthermore, no cracks or pinholes penetrated through the layers, i.e., the TaC layers are highly reliable protective coatings. The analysis also indicated that no plastic deformation occurred during the production process, and the non-textured crystalline orientation of the TaC layers is the origin of their high reliability and durability. The TaC-coated graphite crucibles were tested in an aluminum nitride (AlN) sublimation growth process, which involves extremely corrosive conditions, and demonstrated their practical reliability and durability in the AlN growth process as a TaC-coated graphite. The application of the TaC-coated graphite materials to crucibles and susceptors for use in bulk AlN single crystal growth, bulk silicon carbide (SiC) single crystal growth, chemical vapor deposition of epitaxial SiC films, and metal-organic vapor phase epitaxy of group-III nitrides will lead to further improvements in crystal quality and reduced processing costs.

  3. Sintered tantalum carbide coatings on graphite substrates: Highly reliable protective coatings for bulk and epitaxial growth

    International Nuclear Information System (INIS)

    Nakamura, Daisuke; Suzumura, Akitoshi; Shigetoh, Keisuke

    2015-01-01

    Highly reliable low-cost protective coatings have been sought after for use in crucibles and susceptors for bulk and epitaxial film growth processes involving wide bandgap materials. Here, we propose a production technique for ultra-thick (50–200 μmt) tantalum carbide (TaC) protective coatings on graphite substrates, which consists of TaC slurry application and subsequent sintering processes, i.e., a wet ceramic process. Structural analysis of the sintered TaC layers indicated that they have a dense granular structure containing coarse grain with sizes of 10–50 μm. Furthermore, no cracks or pinholes penetrated through the layers, i.e., the TaC layers are highly reliable protective coatings. The analysis also indicated that no plastic deformation occurred during the production process, and the non-textured crystalline orientation of the TaC layers is the origin of their high reliability and durability. The TaC-coated graphite crucibles were tested in an aluminum nitride (AlN) sublimation growth process, which involves extremely corrosive conditions, and demonstrated their practical reliability and durability in the AlN growth process as a TaC-coated graphite. The application of the TaC-coated graphite materials to crucibles and susceptors for use in bulk AlN single crystal growth, bulk silicon carbide (SiC) single crystal growth, chemical vapor deposition of epitaxial SiC films, and metal-organic vapor phase epitaxy of group-III nitrides will lead to further improvements in crystal quality and reduced processing costs

  4. Software reliability growth models with normal failure time distributions

    International Nuclear Information System (INIS)

    Okamura, Hiroyuki; Dohi, Tadashi; Osaki, Shunji

    2013-01-01

    This paper proposes software reliability growth models (SRGM) where the software failure time follows a normal distribution. The proposed model is mathematically tractable and has sufficient ability of fitting to the software failure data. In particular, we consider the parameter estimation algorithm for the SRGM with normal distribution. The developed algorithm is based on an EM (expectation-maximization) algorithm and is quite simple for implementation as software application. Numerical experiment is devoted to investigating the fitting ability of the SRGMs with normal distribution through 16 types of failure time data collected in real software projects

  5. Growth characteristics of liquid cultures increase the reliability of presumptive identification of Mycobacterium tuberculosis complex.

    Science.gov (United States)

    Pinhata, Juliana Maira Watanabe; Felippe, Isis Moreira; Gallo, Juliana Failde; Chimara, Erica; Ferrazoli, Lucilaine; de Oliveira, Rosangela Siqueira

    2018-04-23

    We evaluated the microscopic and macroscopic characteristics of mycobacteria growth indicator tube (MGIT) cultures for the presumptive identification of the Mycobacterium tuberculosis complex (MTBC) and assessed the reliability of this strategy for correctly directing isolates to drug susceptibility testing (DST) or species identification. A total of 1526 isolates of mycobacteria received at the Instituto Adolfo Lutz were prospectively subjected to presumptive identification by the observation of growth characteristics along with cord formation detection via microscopy. The presumptive identification showed a sensitivity, specificity and accuracy of 98.8, 92.5 and 97.9 %, respectively. Macroscopic analysis of MTBC isolates that would have been erroneously classified as non-tuberculous mycobacteria based solely on microscopic morphology enabled us to direct them rapidly to DST, representing a substantial gain to patients. In conclusion, the growth characteristics of mycobacteria in MGIT, when considered along with cord formation, increased the reliability of the presumptive identification, which has a great impact on the laboratory budget and turnaround times.

  6. Assessing the Reliability of Curriculum-Based Measurement: An Application of Latent Growth Modeling

    Science.gov (United States)

    Yeo, Seungsoo; Kim, Dong-Il; Branum-Martin, Lee; Wayman, Miya Miura; Espin, Christine A.

    2012-01-01

    The purpose of this study was to demonstrate the use of Latent Growth Modeling (LGM) as a method for estimating reliability of Curriculum-Based Measurement (CBM) progress-monitoring data. The LGM approach permits the error associated with each measure to differ at each time point, thus providing an alternative method for examining of the…

  7. Life History theory hypotheses on child growth: Potential implications for short and long-term child growth, development and health.

    Science.gov (United States)

    Said-Mohamed, Rihlat; Pettifor, John M; Norris, Shane A

    2018-01-01

    Life history theory integrates ecological, physiological, and molecular layers within an evolutionary framework to understand organisms' strategies to optimize survival and reproduction. Two life history hypotheses and their implications for child growth, development, and health (illustrated in the South African context) are reviewed here. One hypothesis suggests that there is an energy trade-off between linear growth and brain growth. Undernutrition in infancy and childhood may trigger adaptive physiological mechanisms prioritizing the brain at the expense of body growth. Another hypothesis is that the period from conception to infancy is a critical window of developmental plasticity of linear growth, the duration of which may vary between and within populations. The transition from infancy to childhood may mark the end of a critical window of opportunity for improving child growth. Both hypotheses emphasize the developmental plasticity of linear growth and the potential determinants of growth variability (including the role of parent-offspring conflict in maternal resources allocation). Implications of these hypotheses in populations with high burdens of undernutrition and infections are discussed. In South Africa, HIV/AIDS during pregnancy (associated with adverse birth outcomes, short duration of breastfeeding, and social consequences) may lead to a shortened window of developmental plasticity of growth. Furthermore, undernutrition and infectious diseases in children living in South Africa, a country undergoing a rapid nutrition transition, may have adverse consequences on individuals' cognitive abilities and risks of cardio-metabolic diseases. Studies are needed to identify physiological mechanisms underlying energy allocation between biological functions and their potential impacts on health. © 2017 Wiley Periodicals, Inc.

  8. Software reliability

    CERN Document Server

    Bendell, A

    1986-01-01

    Software Reliability reviews some fundamental issues of software reliability as well as the techniques, models, and metrics used to predict the reliability of software. Topics covered include fault avoidance, fault removal, and fault tolerance, along with statistical methods for the objective assessment of predictive accuracy. Development cost models and life-cycle cost models are also discussed. This book is divided into eight sections and begins with a chapter on adaptive modeling used to predict software reliability, followed by a discussion on failure rate in software reliability growth mo

  9. [A reliability growth assessment method and its application in the development of equipment in space cabin].

    Science.gov (United States)

    Chen, J D; Sun, H L

    1999-04-01

    Objective. To assess and predict reliability of an equipment dynamically by making full use of various test informations in the development of products. Method. A new reliability growth assessment method based on army material system analysis activity (AMSAA) model was developed. The method is composed of the AMSAA model and test data conversion technology. Result. The assessment and prediction results of a space-borne equipment conform to its expectations. Conclusion. It is suggested that this method should be further researched and popularized.

  10. SOME IMPLICATIONS OF A CONCEPT OF GROWTH MOTIVATION FOR ADULT EDUCATION THEORY AND PRACTICE.

    Science.gov (United States)

    NOREEN, DAVID SHELDON

    THIS STUDY EXAMINED GROWTH MOTIVATION AS A DEVELOPING CONCEPT AND AS A THEORETICAL CONSTRUCT, AND THE IMPLICATIONS OF THIS THEORY FOR ADULT EDUCATION THEORY AND PRACTICE. SPECIAL ATTENTION WAS GIVEN TO THE THEORETICAL CONSTRUCTS OF ABRAHAM MASLOW, TO THE NATURE OF GROWTH MOTIVATION CONCEPTS IN GENERAL, AND TO FORMS OF SELF UNDERSTANDING AND…

  11. Bayesian methods in reliability

    Science.gov (United States)

    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.

  12. Inter-Rater Reliability and Downstream Financial Implications of Electrocardiography Screening in Young Athletes.

    Science.gov (United States)

    Dhutia, Harshil; Malhotra, Aneil; Yeo, Tee Joo; Ster, Irina Chis; Gabus, Vincent; Steriotis, Alexandros; Dores, Helder; Mellor, Greg; García-Corrales, Carmen; Ensam, Bode; Jayalapan, Viknesh; Ezzat, Vivienne Anne; Finocchiaro, Gherardo; Gati, Sabiha; Papadakis, Michael; Tome-Esteban, Maria; Sharma, Sanjay

    2017-08-01

    Preparticipation screening for cardiovascular disease in young athletes with electrocardiography is endorsed by the European Society of Cardiology and several major sporting organizations. One of the concerns of the ECG as a screening test in young athletes relates to the potential for variation in interpretation. We investigated the degree of variation in ECG interpretation in athletes and its financial impact among cardiologists of differing experience. Eight cardiologists (4 with experience in screening athletes) each reported 400 ECGs of consecutively screened young athletes according to the 2010 European Society of Cardiology recommendations, Seattle criteria, and refined criteria. Cohen κ coefficient was used to calculate interobserver reliability. Cardiologists proposed secondary investigations after ECG interpretation, the costs of which were based on the UK National Health Service tariffs. Inexperienced cardiologists were more likely to classify an ECG as abnormal compared with experienced cardiologists (odds ratio, 1.44; 95% confidence interval, 1.03-2.02). Modification of ECG interpretation criteria improved interobserver reliability for categorizing an ECG as abnormal from poor (2010 European Society of Cardiology recommendations; κ=0.15) to moderate (refined criteria; κ=0.41) among inexperienced cardiologists; however, interobserver reliability was moderate for all 3 criteria among experienced cardiologists (κ=0.40-0.53). Inexperienced cardiologists were more likely to refer athletes for further evaluation compared with experienced cardiologists (odds ratio, 4.74; 95% confidence interval, 3.50-6.43) with poorer interobserver reliability (κ=0.22 versus κ=0.47). Interobserver reliability for secondary investigations after ECG interpretation ranged from poor to fair among inexperienced cardiologists (κ=0.15-0.30) and fair to moderate among experienced cardiologists (κ=0.21-0.46). The cost of cardiovascular evaluation per athlete was $175 (95

  13. Diagnostic reliability of the cervical vertebral maturation method and standing height in the identification of the mandibular growth spurt.

    Science.gov (United States)

    Perinetti, Giuseppe; Contardo, Luca; Castaldo, Attilio; McNamara, James A; Franchi, Lorenzo

    2016-07-01

    To evaluate the capability of both cervical vertebral maturation (CVM) stages 3 and 4 (CS3-4 interval) and the peak in standing height to identify the mandibular growth spurt throughout diagnostic reliability analysis. A previous longitudinal data set derived from 24 untreated growing subjects (15 females and nine males,) detailed elsewhere were reanalyzed. Mandibular growth was defined as annual increments in Condylion (Co)-Gnathion (Gn) (total mandibular length) and Co-Gonion Intersection (Goi) (ramus height) and their arithmetic mean (mean mandibular growth [mMG]). Subsequently, individual annual increments in standing height, Co-Gn, Co-Goi, and mMG were arranged according to annual age intervals, with the first and last intervals defined as 7-8 years and 15-16 years, respectively. An analysis was performed to establish the diagnostic reliability of the CS3-4 interval or the peak in standing height in the identification of the maximum individual increments of each Co-Gn, Co-Goi, and mMG measurement at each annual age interval. CS3-4 and standing height peak show similar but variable accuracy across annual age intervals, registering values between 0.61 (standing height peak, Co-Gn) and 0.95 (standing height peak and CS3-4, mMG). Generally, satisfactory diagnostic reliability was seen when the mandibular growth spurt was identified on the basis of the Co-Goi and mMG increments. Both CVM interval CS3-4 and peak in standing height may be used in routine clinical practice to enhance efficiency of treatments requiring identification of the mandibular growth spurt.

  14. When and why are reliable organizations favored?

    DEFF Research Database (Denmark)

    Ethiraj, Sendil; Yi, Sangyoon

    of the ensuing work examined only corollary implications of this observation. We treat the observation as a research question and ask: when and why are reliable organizations favored by evolutionary forces? Using a simple theoretical model, we direct attention at a minimal set of variables that are implicated...... shocks, reliable organizations can in fact outperform their less reliable counterparts if they can take advantage of the knowledge resident in their historical choices. While these results are counter-intuitive, the caveat is that our results are only an existence proof for our theory rather than...

  15. Impact of Macroeconomic Policies on Poverty and Unemployment Rates in Nigeria, Implications for Attaining Inclusive Growth

    Directory of Open Access Journals (Sweden)

    Philip Nwosa

    2016-04-01

    Full Text Available This paper examined the effect of macroeconomic policies on unemployment and poverty rates in Nigeria from 1980 to 2013 with implication to achieving inclusive growth. The inability of macroeconomic policies in addressing the rising issues unemployment and poverty rates in Nigeria despite the impressive economic growth experience over the last decades has increasingly called for the need for the pursuance of inclusive growth to address the social issues of unemployment and poverty rate. Previous studies have not considered the extent to which macroeconomic policies affects unemployment and poverty rate in Nigeria, and the implication of this relationship to the attainment of inclusive growth in Nigeria. The study adopts the Ordinary Least Square (OLS technique. The study observed that among macroeconomic policy variables only exchange rate significantly influenced unemployment rate while only fiscal policy significantly influenced and poverty rate. This implies that present macroeconomic policies in Nigeria do not guarantee the attainment of inclusive growth in Nigeria. The contribution of the paper is that to achieve inclusive growth that guarantees high employment and reduced poverty rate, there is the need for a re-examination of macroeconomic policy management in Nigeria.

  16. The Self's Development and Ego Growth: Conceptual Analysis and Implications for Counselors.

    Science.gov (United States)

    Hamachek, Don E.

    1985-01-01

    Self development is conceptualized as surrounded by a series of ego rings that spread out from its center. Erikson's first five psychosocial stages are used as the developmental framework within which self-concept, self-esteem, and ego boundaries are viewed as component parts of the self's growth. Counseling implications are used. (Author/BL)

  17. Pocket Handbook on Reliability

    Science.gov (United States)

    1975-09-01

    exponencial distributions Weibull distribution, -xtimating reliability, confidence intervals, relia- bility growth, 0. P- curves, Bayesian analysis. 20 A S...introduction for those not familiar with reliability and a good refresher for those who are currently working in the area. LEWIS NERI, CHIEF...includes one or both of the following objectives: a) prediction of the current system reliability, b) projection on the system reliability for someI future

  18. Detecting long-term growth trends using tree rings: a critical evaluation of methods.

    Science.gov (United States)

    Peters, Richard L; Groenendijk, Peter; Vlam, Mart; Zuidema, Pieter A

    2015-05-01

    Tree-ring analysis is often used to assess long-term trends in tree growth. A variety of growth-trend detection methods (GDMs) exist to disentangle age/size trends in growth from long-term growth changes. However, these detrending methods strongly differ in approach, with possible implications for their output. Here, we critically evaluate the consistency, sensitivity, reliability and accuracy of four most widely used GDMs: conservative detrending (CD) applies mathematical functions to correct for decreasing ring widths with age; basal area correction (BAC) transforms diameter into basal area growth; regional curve standardization (RCS) detrends individual tree-ring series using average age/size trends; and size class isolation (SCI) calculates growth trends within separate size classes. First, we evaluated whether these GDMs produce consistent results applied to an empirical tree-ring data set of Melia azedarach, a tropical tree species from Thailand. Three GDMs yielded similar results - a growth decline over time - but the widely used CD method did not detect any change. Second, we assessed the sensitivity (probability of correct growth-trend detection), reliability (100% minus probability of detecting false trends) and accuracy (whether the strength of imposed trends is correctly detected) of these GDMs, by applying them to simulated growth trajectories with different imposed trends: no trend, strong trends (-6% and +6% change per decade) and weak trends (-2%, +2%). All methods except CD, showed high sensitivity, reliability and accuracy to detect strong imposed trends. However, these were considerably lower in the weak or no-trend scenarios. BAC showed good sensitivity and accuracy, but low reliability, indicating uncertainty of trend detection using this method. Our study reveals that the choice of GDM influences results of growth-trend studies. We recommend applying multiple methods when analysing trends and encourage performing sensitivity and reliability

  19. Reliability Engineering

    CERN Document Server

    Lazzaroni, Massimo

    2012-01-01

    This book gives a practical guide for designers and users in Information and Communication Technology context. In particular, in the first Section, the definition of the fundamental terms according to the international standards are given. Then, some theoretical concepts and reliability models are presented in Chapters 2 and 3: the aim is to evaluate performance for components and systems and reliability growth. Chapter 4, by introducing the laboratory tests, puts in evidence the reliability concept from the experimental point of view. In ICT context, the failure rate for a given system can be

  20. Machine Learning Approach for Software Reliability Growth Modeling with Infinite Testing Effort Function

    Directory of Open Access Journals (Sweden)

    Subburaj Ramasamy

    2017-01-01

    Full Text Available Reliability is one of the quantifiable software quality attributes. Software Reliability Growth Models (SRGMs are used to assess the reliability achieved at different times of testing. Traditional time-based SRGMs may not be accurate enough in all situations where test effort varies with time. To overcome this lacuna, test effort was used instead of time in SRGMs. In the past, finite test effort functions were proposed, which may not be realistic as, at infinite testing time, test effort will be infinite. Hence in this paper, we propose an infinite test effort function in conjunction with a classical Nonhomogeneous Poisson Process (NHPP model. We use Artificial Neural Network (ANN for training the proposed model with software failure data. Here it is possible to get a large set of weights for the same model to describe the past failure data equally well. We use machine learning approach to select the appropriate set of weights for the model which will describe both the past and the future data well. We compare the performance of the proposed model with existing model using practical software failure data sets. The proposed log-power TEF based SRGM describes all types of failure data equally well and also improves the accuracy of parameter estimation more than existing TEF and can be used for software release time determination as well.

  1. The Growth Of Kaduna Metropolis Between 1973 And 2012 The Physical Planning Implications

    Directory of Open Access Journals (Sweden)

    Afon

    2015-08-01

    Full Text Available This paper examined the growth and development pattern of Kaduna metropolis Nigeria over a period of 39 years with a view to identifying its physical planning implications. The study employs the use of Remote Sensing data and GIS technology. Data used for the study include Landsat Imagery of 1973 1990 and 2001 and NigeriaSat-1 of 2006 and GeoEye image of 2012 and the population data for 1963 1991 and 2006. The data was used to determine the pattern of growth rate of growth land consumption rate and land absorption efficiency of the study area. The study established that Kaduna metropolis have been increasing like most cities of the world of which the highest growth was witnessed between 2006 to 2012 with 13.4 growth rate per annum. It also revealed that the pattern of growths witnessed were along the major routes. The study also revealed that there is a relationship between population growth and urban growth in Kaduna metropolis The study concluded that the need for available data is vital to the understanding of the dynamic of the urban environment. More commitment had to be done on the part of government and research to ensure that the gap is closed.

  2. The Implications of Growth Policy for Postsecondary Education. A Model and Proposed Course of Action. Working Paper.

    Science.gov (United States)

    Perelman, Lewis J.; Bergquist, William H.

    A 5-month project was undertaken at the Western Interstate Commission for Higher Education to do a preliminary study of the implications of growth policy for postsecondary education. The decision to focus on this level of education was based on the belief that the existing problems of growth and its limits have become too urgent to be left to…

  3. Simulating Population Growth.

    Science.gov (United States)

    Byington, Scott

    1997-01-01

    Presents a strategy to help students grasp the important implications of population growth. Involves an interactive demonstration that allows students to experience exponential and logistic population growth followed by a discussion of the implications of population-growth principles. (JRH)

  4. Reliability of length measurements collected by community nurses and health volunteers in rural growth monitoring and promotion services.

    Science.gov (United States)

    Laar, Matilda E; Marquis, Grace S; Lartey, Anna; Gray-Donald, Katherine

    2018-02-17

    Length measurements are important in growth, monitoring and promotion (GMP) for the surveillance of a child's weight-for-length and length-for-age. These two indices provide an indication of a child's risk of becoming wasted or stunted, and are more informative about a child's growth than the widely used weight-for-age index (underweight). Although the introduction of length measurements in GMP is recommended by the World Health Organization, concerns about the reliability of length measurements collected in rural outreach settings have been expressed by stakeholders. Our aim was to describe the reliability and challenges associated with community health personnel measuring length for rural outreach GMP activities. Two reliability studies (A and B), using 10 children less than 24 months each, were conducted in the GMP services of a rural district in Ghana. Fifteen nurses and 15 health volunteers (HV) with no prior experience in length measurements were trained. Intra- and inter-observer technical error of measurement (TEM), average bias from expert anthropometrist, and coefficient of reliability (R) of length measurements were assessed and compared across sessions. Observations and interviews were used to understand the ability and experiences of health personnel with measuring length at outreach GMP. Inter-observer TEM was larger than intra-observer TEM for both nurses and HV at both sessions and was unacceptably (compared to error standards) high in both groups at both time points. Average biases from expert's measurements were within acceptable limits, however, both groups tended to underestimate length measurements. The R for lengths collected by nurses (92.3%) was higher at session B compared to that of HV (87.5%). Length measurements taken by nurses and HV, and those taken by an experienced anthropometrist at GMP sessions were of moderate agreement (kappa = 0.53, p reliability of length measurements improved after two refresher trainings for nurses but

  5. Software reliability through fault-avoidance and fault-tolerance

    Science.gov (United States)

    Vouk, Mladen A.; Mcallister, David F.

    1992-01-01

    Accomplishments in the following research areas are summarized: structure based testing, reliability growth, and design testability with risk evaluation; reliability growth models and software risk management; and evaluation of consensus voting, consensus recovery block, and acceptance voting. Four papers generated during the reporting period are included as appendices.

  6. Tracking reliability for space cabin-borne equipment in development by Crow model.

    Science.gov (United States)

    Chen, J D; Jiao, S J; Sun, H L

    2001-12-01

    Objective. To study and track the reliability growth of manned spaceflight cabin-borne equipment in the course of its development. Method. A new technique of reliability growth estimation and prediction, which is composed of the Crow model and test data conversion (TDC) method was used. Result. The estimation and prediction value of the reliability growth conformed to its expectations. Conclusion. The method could dynamically estimate and predict the reliability of the equipment by making full use of various test information in the course of its development. It offered not only a possibility of tracking the equipment reliability growth, but also the reference for quality control in manned spaceflight cabin-borne equipment design and development process.

  7. Ecological network analysis for economic systems: growth and development and implications for sustainable development.

    Science.gov (United States)

    Huang, Jiali; Ulanowicz, Robert E

    2014-01-01

    The quantification of growth and development is an important issue in economics, because these phenomena are closely related to sustainability. We address growth and development from a network perspective in which economic systems are represented as flow networks and analyzed using ecological network analysis (ENA). The Beijing economic system is used as a case study and 11 input-output (I-O) tables for 1985-2010 are converted into currency networks. ENA is used to calculate system-level indices to quantify the growth and development of Beijing. The contributions of each direct flow toward growth and development in 2010 are calculated and their implications for sustainable development are discussed. The results show that during 1985-2010, growth was the main attribute of the Beijing economic system. Although the system grew exponentially, its development fluctuated within only a small range. The results suggest that system ascendency should be increased in order to favor more sustainable development. Ascendency can be augmented in two ways: (1) strengthen those pathways with positive contributions to increasing ascendency and (2) weaken those with negative effects.

  8. Bayes Analysis and Reliability Implications of Stress-Rupture Testing a Kevlar/Epoxy COPV Using Temperature and Pressure Acceleration

    Science.gov (United States)

    Phoenix, S. Leigh; Kezirian, Michael T.; Murthy, Pappu L. N.

    2009-01-01

    Composite Overwrapped Pressure Vessels (COPVs) that have survived a long service time under pressure generally must be recertified before service is extended. Flight certification is dependent on the reliability analysis to quantify the risk of stress rupture failure in existing flight vessels. Full certification of this reliability model would require a statistically significant number of lifetime tests to be performed and is impractical given the cost and limited flight hardware for certification testing purposes. One approach to confirm the reliability model is to perform a stress rupture test on a flight COPV. Currently, testing of such a Kevlar49 (Dupont)/epoxy COPV is nearing completion. The present paper focuses on a Bayesian statistical approach to analyze the possible failure time results of this test and to assess the implications in choosing between possible model parameter values that in the past have had significant uncertainty. The key uncertain parameters in this case are the actual fiber stress ratio at operating pressure, and the Weibull shape parameter for lifetime; the former has been uncertain due to ambiguities in interpreting the original and a duplicate burst test. The latter has been uncertain due to major differences between COPVs in the database and the actual COPVs in service. Any information obtained that clarifies and eliminates uncertainty in these parameters will have a major effect on the predicted reliability of the service COPVs going forward. The key result is that the longer the vessel survives, the more likely the more optimistic stress ratio model is correct. At the time of writing, the resulting effect on predicted future reliability is dramatic, increasing it by about one "nine," that is, reducing the predicted probability of failure by an order of magnitude. However, testing one vessel does not change the uncertainty on the Weibull shape parameter for lifetime since testing several vessels would be necessary.

  9. Probabilistic modeling of fatigue crack growth in Ti-6Al-4V

    International Nuclear Information System (INIS)

    Soboyejo, W.O.; Shen, W.; Soboyejo, A.B.O.

    2001-01-01

    This paper presents the results of a combined experimental and analytical study of the probabilistic nature of fatigue crack growth in Ti-6Al-4V. A simple experimental fracture mechanics framework is presented for the determination of statistical fatigue crack growth parameters from two fatigue tests. The experimental studies show that the variabilities in long fatigue crack growth rate data and the Paris coefficient are well described by the log-normal distributions. The variabilities in the Paris exponent are also shown to be well characterized by a normal distribution. The measured statistical distributions are incorporated into a probabilistic fracture mechanics framework for the estimation of material reliability. The implications of the results are discussed for the probabilistic analysis of fatigue crack growth in engineering components and structures. (orig.)

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

    Science.gov (United States)

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

    2010-01-01

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

  11. An examination of reliability critical items in liquid metal reactors: An analysis by the Centralized Reliability Data Organization (CREDO)

    International Nuclear Information System (INIS)

    Humphrys, B.L.; Haire, M.J.; Koger, K.H.; Manneschmidt, J.F.; Setoguchi, K.; Nakai, R.; Okubo, Y.

    1987-01-01

    The Centralized Reliability Data Organization (CREDO) is the largest repository of liquid metal reactor (LMR) component reliability data in the world. It is jointly sponsored by the US Department of Energy (DOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. The CREDO data base contains information on a population of more than 21,000 components and approximately 1300 event records. A conservative estimation is that the total component operating hours is approaching 3.5 billion hours. Because data gathering for CREDO concentrates on event (failure) information, the work reported here focuses on the reliability information contained in CREDO and the development of reliability critical items lists. That is, components are ranked in prioritized lists from worst to best performers from a reliability standpoint. For the data contained in the CREDO data base, FFTF and JOYO show reliability growth; EBR-II reveals a slight unreliability growth for those components tracked by CREDO. However, tabulations of events which cause reactor shutdowns decrease with time at each site

  12. Implications Of Foreign Direct Investment, Financial Development And Real Exchange Rate For Economic Growth In Cameroon

    Directory of Open Access Journals (Sweden)

    Victalice Ngimanang Achamoh

    2016-05-01

    Full Text Available This paper assesses the effects of foreign direct investment (FDI, financial development and real exchange rate (RER on economic growth in Cameroon using Cameroon’s annual time series data spanning the period 1977 - 2010. To address these objectives, residual based Engle-Granger test, the OLS based Autoregressive Distributive Lag (ARDL bound testing and maximum likelihood based Johansen cointegration techniques are employed. Results of Unit roots tests show that all the series possessed unit roots at level or first difference form. The ARDL model and VECM results reveal that the RER has a significant negative effect on economic growth, while FDI and Financial Development relate positively to economic growth. These findings have implications for stimulating economic growth by increasing efficiency of the financial sector in allocating credit to the private sector and preventing real exchange rate appreciation in the shortrun.

  13. Adolescent inhalant abuse leads to other drug use and impaired growth; implications for diagnosis.

    Science.gov (United States)

    Crossin, Rose; Cairney, Sheree; Lawrence, Andrew J; Duncan, Jhodie R

    2017-02-01

    Abuse of inhalants containing the volatile solvent toluene is a significant public health issue, especially for adolescent and Indigenous communities. Adolescent inhalant abuse can lead to chronic health issues and may initiate a trajectory towards further drug use. Identification of at-risk individuals is difficult and diagnostic tools are limited primarily to measurement of serum toluene. Our objective was to identify the effects of adolescent inhalant abuse on subsequent drug use and growth parameters, and to test the predictive power of growth parameters as a diagnostic measure for inhalant abuse. We retrospectively analysed drug use and growth data from 118 Indigenous males; 86 chronically sniffed petrol as adolescents. Petrol sniffing was the earliest drug used (mean 13 years) and increased the likelihood and earlier use of other drugs. Petrol sniffing significantly impaired height and weight and was associated with meeting 'failure to thrive' criteria; growth diagnostically out-performed serum toluene. Adolescent inhalant abuse increases the risk for subsequent and earlier drug use. It also impairs growth such that individuals meet 'failure to thrive' criteria, representing an improved diagnostic model for inhalant abuse. Implications for Public Health: Improved diagnosis of adolescent inhalant abuse may lead to earlier detection and enhanced health outcomes. © 2016 The Authors.

  14. Integrated Markov-neural reliability computation method: A case for multiple automated guided vehicle system

    International Nuclear Information System (INIS)

    Fazlollahtabar, Hamed; Saidi-Mehrabad, Mohammad; Balakrishnan, Jaydeep

    2015-01-01

    This paper proposes an integrated Markovian and back propagation neural network approaches to compute reliability of a system. While states of failure occurrences are significant elements for accurate reliability computation, Markovian based reliability assessment method is designed. Due to drawbacks shown by Markovian model for steady state reliability computations and neural network for initial training pattern, integration being called Markov-neural is developed and evaluated. To show efficiency of the proposed approach comparative analyses are performed. Also, for managerial implication purpose an application case for multiple automated guided vehicles (AGVs) in manufacturing networks is conducted. - Highlights: • Integrated Markovian and back propagation neural network approach to compute reliability. • Markovian based reliability assessment method. • Managerial implication is shown in an application case for multiple automated guided vehicles (AGVs) in manufacturing networks

  15. One Iota Fills the Quota: A Paradox in Multifacet Reliability Coefficients.

    Science.gov (United States)

    Conger, Anthony J.

    1983-01-01

    A paradoxical phenomenon of decreases in reliability as the number of elements averaged over increases is shown to be possible in multifacet reliability procedures (intraclass correlations or generalizability coefficients). Conditions governing this phenomenon are presented along with implications and cautions. (Author)

  16. Wind turbine reliability : a database and analysis approach.

    Energy Technology Data Exchange (ETDEWEB)

    Linsday, James (ARES Corporation); Briand, Daniel; Hill, Roger Ray; Stinebaugh, Jennifer A.; Benjamin, Allan S. (ARES Corporation)

    2008-02-01

    The US wind Industry has experienced remarkable growth since the turn of the century. At the same time, the physical size and electrical generation capabilities of wind turbines has also experienced remarkable growth. As the market continues to expand, and as wind generation continues to gain a significant share of the generation portfolio, the reliability of wind turbine technology becomes increasingly important. This report addresses how operations and maintenance costs are related to unreliability - that is the failures experienced by systems and components. Reliability tools are demonstrated, data needed to understand and catalog failure events is described, and practical wind turbine reliability models are illustrated, including preliminary results. This report also presents a continuing process of how to proceed with controlling industry requirements, needs, and expectations related to Reliability, Availability, Maintainability, and Safety. A simply stated goal of this process is to better understand and to improve the operable reliability of wind turbine installations.

  17. Assessing reliability of fatigue indicator parameters for small crack growth via a probabilistic framework

    Science.gov (United States)

    Rovinelli, Andrea; Guilhem, Yoann; Proudhon, Henry; Lebensohn, Ricardo A.; Ludwig, Wolfgang; Sangid, Michael D.

    2017-06-01

    Microstructurally small cracks exhibit large variability in their fatigue crack growth rate. It is accepted that the inherent variability in microstructural features is related to the uncertainty in the growth rate. However, due to (i) the lack of cycle-by-cycle experimental data, (ii) the complexity of the short crack growth phenomenon, and (iii) the incomplete physics of constitutive relationships, only empirical damage metrics have been postulated to describe the short crack driving force metric (SCDFM) at the mesoscale level. The identification of the SCDFM of polycrystalline engineering alloys is a critical need, in order to achieve more reliable fatigue life prediction and improve material design. In this work, the first steps in the development of a general probabilistic framework are presented, which uses experimental result as an input, retrieves missing experimental data through crystal plasticity (CP) simulations, and extracts correlations utilizing machine learning and Bayesian networks (BNs). More precisely, experimental results representing cycle-by-cycle data of a short crack growing through a beta-metastable titanium alloy, VST-55531, have been acquired via phase and diffraction contrast tomography. These results serve as an input for FFT-based CP simulations, which provide the micromechanical fields influenced by the presence of the crack, complementing the information available from the experiment. In order to assess the correlation between postulated SCDFM and experimental observations, the data is mined and analyzed utilizing BNs. Results show the ability of the framework to autonomously capture relevant correlations and the equivalence in the prediction capability of different postulated SCDFMs for the high cycle fatigue regime.

  18. QA support for TFTR reliability improvement program in preparation for DT operation

    International Nuclear Information System (INIS)

    Parsells, R.F.; Howard, H.P.

    1987-01-01

    As TFTR approaches experiments in the Q=1 regime, machine reliability becomes a major variable in achieving experimental objectives. This paper describes the methods used to quantify current reliability levels, levels required for D-T operations, proposed methods for reliability growth and improvement, and tracking of reliability performance in that growth. Included in this scope are data collection techniques and short comings, bounding current reliability on the upper end, and requirements for D-T operations. Problem characterization through Pareto diagrams provides insight into recurrent failure modes and the use of Duane plots for charting of reliability changes both cumulative and instantaneous, is explained and demonstrated

  19. Growth recovery and faltering through early adolescence in low- and middle-income countries: Determinants and implications for cognitive development.

    Science.gov (United States)

    Georgiadis, Andreas; Benny, Liza; Duc, Le Thuc; Galab, Sheikh; Reddy, Prudhvikar; Woldehanna, Tassew

    2017-04-01

    Child chronic undernutrition, as measured by stunting, is prevalent in low- and middle-income countries and is among the major threats to child development. While stunting and its implications for cognitive development have been considered irreversible beyond early childhood there is a lack of consensus in the literature on this, as there is some evidence of recovery from stunting and that this recovery may be associated with improvements in cognition. Less is known however, about the drivers of growth recovery and the aspects of recovery linked to cognitive development. In this paper we investigate the factors associated with growth recovery and faltering through age 12 years and the implications of the incidence, timing, and persistence of post-infancy recovery from stunting for cognitive development using longitudinal data from Ethiopia, India, Peru, and Vietnam. We find that the factors most systematically associated with accelerated growth both before and after early childhood and across countries include mother's height, household living standards and shocks, community wages, food prices, and garbage collection. Our results suggest that post-infancy recovery from stunting is more likely to be systematically associated with higher achievement scores across countries when it is persistent and that associations between growth trajectories and cognitive achievement in middle childhood do not persist through early adolescence across countries. Overall, our findings indicate that growth after early childhood is responsive to changes in the household and community environments and that growth promotion after early childhood may yield improvements in child cognitive development. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Is the Holocaust implicated in posttraumatic growth in second-generation Holocaust survivors? A prospective study.

    Science.gov (United States)

    Dekel, Sharon; Mandl, Christine; Solomon, Zahava

    2013-08-01

    With the growing interest in posttraumatic growth (PTG), and the ongoing debate on the implications of transgenerational transmission of trauma, this longitudinal study examined PTG among Holocaust survivor offspring following their own exposure to trauma. Using self-report questionnaires, we assessed PTG over time in middle aged (age: M = 53 years) Israeli male combat veterans of the 1973 Yom Kippur War whose parents were (n = 43) and were not (n = 156) second-generation survivors of the Nazi Holocaust at 2 time points: 30 and 35 years following the war (in 2003 and 2008). Posttraumatic stress disorder symptoms and trauma exposure were also assessed in 1991. We hypothesized that second-generation survivors would report more PTG than controls. However, repeated measures design revealed that the second-generation veterans reported less PTG than veterans who were not second generation, which was evident in the PTG domains of relations to others, personal strength, and appreciation of life. Our findings suggest that transmission of trauma from one generation to the next is possibly implicated in the offspring's propensity for growth following subsequent trauma. Future research is warranted to examine the link between transmission of trauma and positive outcomes following trauma. Copyright © 2013 International Society for Traumatic Stress Studies.

  1. EPRI (Electric Power Research Institute) operator reliability experiments program - Training implications

    International Nuclear Information System (INIS)

    Joksimovich, V.; Spurgin, A.J.; Orvis, D.D.; Moieni, P.; Worledge, D.H.

    1990-01-01

    The primary purpose of the EPRI Operator Reliability Experiments (ORE) Program is to collect data for use in reliability and safety studies of nuclear power plant operation to more realistically take credit for operator performance in preventing core damage. The two objectives for fulfilling this purpose are: (1) to obtain quantitative/qualitative performance data on operating crew responses in the control room for potential accident sequences by using plant simulators, and (2) to test the Human Cognitive Reliability (HCR) correlation. This paper briefly discusses the background to this program, data collection and analysis, the results and quantitative/qualitative insights stemming from phase one which might be of interest to simulator operators and trainers

  2. Predicting Cost/Reliability/Maintainability of Advanced General Aviation Avionics Equipment

    Science.gov (United States)

    Davis, M. R.; Kamins, M.; Mooz, W. E.

    1978-01-01

    A methodology is provided for assisting NASA in estimating the cost, reliability, and maintenance (CRM) requirements for general avionics equipment operating in the 1980's. Practical problems of predicting these factors are examined. The usefulness and short comings of different approaches for modeling coast and reliability estimates are discussed together with special problems caused by the lack of historical data on the cost of maintaining general aviation avionics. Suggestions are offered on how NASA might proceed in assessing cost reliability CRM implications in the absence of reliable generalized predictive models.

  3. Sequential decision reliability concept and failure rate assessment

    International Nuclear Information System (INIS)

    Ciftcioglu, O.

    1990-11-01

    Conventionally, a reliability concept is considered together with both each basic unit and their integration in a complicated large scale system such as a nuclear power plant (NPP). Basically, as the plant's operational status is determined by the information obtained from various sensors, the plant's reliability and the risk assessment is closely related to the reliability of the sensory information and hence the sensor components. However, considering the relevant information-processing systems, e.g. fault detection processors, there exists a further question about the reliability of such systems, specifically the reliability of the systems' decision-based outcomes by means of which the further actions are performed. To this end, a general sequential decision reliability concept and the failure rate assessment methodology is introduced. The implications of the methodology are investigated and the importance of the decision reliability concept in system operation is demonstrated by means of sensory signals in real-time from the Borssele NPP in the Netherlands. (author). 21 refs.; 8 figs

  4. Developing safety performance functions incorporating reliability-based risk measures.

    Science.gov (United States)

    Ibrahim, Shewkar El-Bassiouni; Sayed, Tarek

    2011-11-01

    Current geometric design guides provide deterministic standards where the safety margin of the design output is generally unknown and there is little knowledge of the safety implications of deviating from these standards. Several studies have advocated probabilistic geometric design where reliability analysis can be used to account for the uncertainty in the design parameters and to provide a risk measure of the implication of deviation from design standards. However, there is currently no link between measures of design reliability and the quantification of safety using collision frequency. The analysis presented in this paper attempts to bridge this gap by incorporating a reliability-based quantitative risk measure such as the probability of non-compliance (P(nc)) in safety performance functions (SPFs). Establishing this link will allow admitting reliability-based design into traditional benefit-cost analysis and should lead to a wider application of the reliability technique in road design. The present application is concerned with the design of horizontal curves, where the limit state function is defined in terms of the available (supply) and stopping (demand) sight distances. A comprehensive collision and geometric design database of two-lane rural highways is used to investigate the effect of the probability of non-compliance on safety. The reliability analysis was carried out using the First Order Reliability Method (FORM). Two Negative Binomial (NB) SPFs were developed to compare models with and without the reliability-based risk measures. It was found that models incorporating the P(nc) provided a better fit to the data set than the traditional (without risk) NB SPFs for total, injury and fatality (I+F) and property damage only (PDO) collisions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Reliability and Robustness Analysis of the Masinga Dam under Uncertainty

    Directory of Open Access Journals (Sweden)

    Hayden Postle-Floyd

    2017-02-01

    Full Text Available Kenya’s water abstraction must meet the projected growth in municipal and irrigation demand by the end of 2030 in order to achieve the country’s industrial and economic development plan. The Masinga dam, on the Tana River, is the key to meeting this goal to satisfy the growing demands whilst also continuing to provide hydroelectric power generation. This study quantitatively assesses the reliability and robustness of the Masinga dam system under uncertain future supply and demand using probabilistic climate and population projections, and examines how long-term planning may improve the longevity of the dam. River flow and demand projections are used alongside each other as inputs to the dam system simulation model linked to an optimisation engine to maximise water availability. Water availability after demand satisfaction is assessed for future years, and the projected reliability of the system is calculated for selected years. The analysis shows that maximising power generation on a short-term year-by-year basis achieves 80%, 50% and 1% reliability by 2020, 2025 and 2030 onwards, respectively. Longer term optimal planning, however, has increased system reliability to up to 95% in 2020, 80% in 2025, and more than 40% in 2030 onwards. In addition, increasing the capacity of the reservoir by around 25% can significantly improve the robustness of the system for all future time periods. This study provides a platform for analysing the implication of different planning and management of Masinga dam and suggests that careful consideration should be given to account for growing municipal needs and irrigation schemes in both the immediate and the associated Tana River basin.

  6. PV Systems Reliability Final Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Lavrova, Olga [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flicker, Jack David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Armijo, Kenneth Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gonzalez, Sigifredo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schindelholz, Eric John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorensen, Neil R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yang, Benjamin Bing-Yeh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

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

  7. Reliability analysis techniques for the design engineer

    International Nuclear Information System (INIS)

    Corran, E.R.; Witt, H.H.

    1982-01-01

    This paper describes a fault tree analysis package that eliminates most of the housekeeping tasks involved in proceeding from the initial construction of a fault tree to the final stage of presenting a reliability analysis in a safety report. It is suitable for designers with relatively little training in reliability analysis and computer operation. Users can rapidly investigate the reliability implications of various options at the design stage and evolve a system which meets specified reliability objectives. Later independent review is thus unlikely to reveal major shortcomings necessitating modification and project delays. The package operates interactively, allowing the user to concentrate on the creative task of developing the system fault tree, which may be modified and displayed graphically. For preliminary analysis, system data can be derived automatically from a generic data bank. As the analysis proceeds, improved estimates of critical failure rates and test and maintenance schedules can be inserted. The technique is applied to the reliability analysis of the recently upgraded HIFAR Containment Isolation System. (author)

  8. Anisotropic Growth of Otavite on Calcite: Implications for Heteroepitaxial Growth Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Riechers, Shawn L.; Kerisit, Sebastien N.

    2017-12-18

    Elucidating how cation intermixing can affect the mechanisms of heteroepitaxial growth in aqueous media has remained a challenging endeavor. Toward this goal, in situ atomic force microscopy was employed to image the heteroepitaxial growth of otavite (CdCO3) at the (10-14) surface of calcite (CaCO3) single crystals in static aqueous conditions. Heteroepitaxial growth proceeded via spreading of three-dimensional (3D) islands and two-dimensional (2D) atomic layers at low and high initial saturation levels, respectively. Experiments were carried out as a function of applied force and imaging mode thus enabling determination of growth mechanisms unaltered by imaging artifacts. This approach revealed the significant anisotropic nature of heteroepitaxial growth on calcite in both growth modes and its dependence on supersaturation, intermixing, and substrate topography. The 3D islands not only grew preferentially along the [42-1] direction relative to the [010] direction, resulting in rod-like surface precipitates, but also showed clear preference for growth from the island end rich in obtuse/obtuse kink sites. Pinning to step edges was observed to often reverse this tendency. In the 2D growth mode, the relative velocities of acute and obtuse steps were observed to switch between the first and second atomic layers. This phenomenon stemmed from the significant Cd-Ca intermixing in the first layer, despite bulk thermodynamics predicting the formation of almost pure otavite. Composition effects were also responsible for the inability of 3D islands to grow on 2D layers in cases where both modes were observed to occur simultaneously. Overall, the AFM images highlighted the effects of intermixing on heteroepitaxial growth, particularly how it can induce thickness-dependent growth mechanisms at the nanoscale.

  9. Finite element reliability analysis of fatigue life

    International Nuclear Information System (INIS)

    Harkness, H.H.; Belytschko, T.; Liu, W.K.

    1992-01-01

    Fatigue reliability is addressed by the first-order reliability method combined with a finite element method. Two-dimensional finite element models of components with cracks in mode I are considered with crack growth treated by the Paris law. Probability density functions of the variables affecting fatigue are proposed to reflect a setting where nondestructive evaluation is used, and the Rosenblatt transformation is employed to treat non-Gaussian random variables. Comparisons of the first-order reliability results and Monte Carlo simulations suggest that the accuracy of the first-order reliability method is quite good in this setting. Results show that the upper portion of the initial crack length probability density function is crucial to reliability, which suggests that if nondestructive evaluation is used, the probability of detection curve plays a key role in reliability. (orig.)

  10. Reliability and protection against failure in computer systems

    International Nuclear Information System (INIS)

    Daniels, B.K.

    1979-01-01

    Computers are being increasingly integrated into the control and safety systems of large and potentially hazardous industrial processes. This development introduces problems which are particular to computer systems and opens the way to new techniques of solving conventional reliability and availability problems. References to the developing fields of software reliability, human factors and software design are given, and these subjects are related, where possible, to the quantified assessment of reliability. Original material is presented in the areas of reliability growth and computer hardware failure data. The report draws on the experience of the National Centre of Systems Reliability in assessing the capability and reliability of computer systems both within the nuclear industry, and from the work carried out in other industries by the Systems Reliability Service. (author)

  11. Green Economy Performance and Green Productivity Growth in China’s Cities: Measures and Policy Implication

    Directory of Open Access Journals (Sweden)

    Jianglong Li

    2016-09-01

    Full Text Available Resource depletion and environmental degradation have become serious challenges for China’s sustainable development. This paper constructs indicators to assess China’s green economy performance and green productivity growth, in which economic expansion, resource conservation and environmental protection need to be incorporated simultaneously. For this purpose, we combine non-radial directional distance function and meta-frontier Malmquist productivity to develop the indicators. The methodology also allows for the decomposition of driving forces of China’s green economy. Moreover, the dataset employed in this paper allows for the evaluation of 275 cities in China during the period 2003–2012. The main findings are as follows. First, most of China’s cities did not perform efficiently in terms of the green economy, with an average score of only 0.233. Second, the growth rate of green productivity is slower than real GDP, and the green productivity growth in China is only moderate. Third, innovation is the main driving force of China’s green productivity growth, but the central region lags behind when it comes to green innovation. Fourth, artificial local protectionism and transport limitations impede the progress of cities that perform ineffectively in the green economy. Based on our empirical findings, we provide policy implications and suggestions for enhancing China’s green economy performance and productivity growth.

  12. Integrated reliability condition monitoring and maintenance of equipment

    CERN Document Server

    Osarenren, John

    2015-01-01

    Consider a Viable and Cost-Effective Platform for the Industries of the Future (IOF) Benefit from improved safety, performance, and product deliveries to your customers. Achieve a higher rate of equipment availability, performance, product quality, and reliability. Integrated Reliability: Condition Monitoring and Maintenance of Equipment incorporates reliable engineering and mathematical modeling to help you move toward sustainable development in reliability condition monitoring and maintenance. This text introduces a cost-effective integrated reliability growth monitor, integrated reliability degradation monitor, technological inheritance coefficient sensors, and a maintenance tool that supplies real-time information for predicting and preventing potential failures of manufacturing processes and equipment. The author highlights five key elements that are essential to any improvement program: improving overall equipment and part effectiveness, quality, and reliability; improving process performance with maint...

  13. Product quality, service reliability and management of operations at ...

    African Journals Online (AJOL)

    High product quality, service reliability, and management of operations are key factors in business growth and sustainability. Analyzing “The Starbucks Experience” is a pedagogical approach to reinforcing the concepts of control and management of quality, service reliability, and efficient operations in action. The objective ...

  14. Expression of receptors for putative anabolic growth factors in human intervertebral disc: implications for repair and regeneration of the disc.

    Science.gov (United States)

    Le Maitre, Christine L; Richardson, Stephen M A; Baird, Pauline; Freemont, Anthony J; Hoyland, Judith A

    2005-12-01

    Low back pain (LBP) is a common, debilitating and economically important disorder. Current evidence implicates loss of intervertebral disc (IVD) matrix consequent upon 'degeneration' as a major cause of LBP. Degeneration of the IVD involves increases in degradative enzymes and decreases in the extracellular matrix (ECM) component in a process that is controlled by a range of cytokines and growth factors. Studies have suggested using anabolic growth factors to regenerate the normal matrix of the IVD, hence restoring disc height and reversing degenerative disc disease. However, for such therapies to be successful it is vital that the target cells (i.e. the disc cells) express the appropriate receptors. This immunohistochemical study has for the first time investigated the expression and localization of four potentially beneficial growth factor receptors (i.e. TGFbetaRII, BMPRII, FGFR3 and IGFRI) in non-degenerate and degenerate human IVDs. Receptor expression was quantified across regions of the normal and degenerate disc and showed that cells of the nucleus pulposus (NP) and inner annulus fibrosus (IAF) expressed significantly higher levels of the four growth factor receptors investigated. There were no significant differences between the four growth factor expression in non-degenerate and degenerate biopsies. However, expression of TGFbetaRII, FGFR3 and IGFRI, but not BMP RII, were observed in the ingrowing blood vessels that characterize part of the disease aetiology. In conclusion, this study has demonstrated the expression of the four growth factor receptors at similar levels in the chondrocyte-like cells of the NP and IAF in both non-degenerate and degenerate discs, implicating a role in normal disc homeostasis and suggesting that the application of these growth factors to the degenerate human IVD would stimulate matrix production. However, the expression of some of the growth factor receptors on ingrowing blood vessels might be problematic in a therapeutic

  15. Reliability growth of thin film resistors contact

    Directory of Open Access Journals (Sweden)

    Lugin A. N.

    2010-10-01

    Full Text Available Necessity of resistive layer growth under the contact and in the contact zone of resistive element is shown in order to reduce peak values of current flow and power dissipation in the contact of thin film resistor, thereby to increase the resistor stability to parametric and catastrophic failures.

  16. Reliability of the American Medical Association guides' model for measuring spinal range of motion. Its implication for whole-person impairment rating.

    Science.gov (United States)

    Nitschke, J E; Nattrass, C L; Disler, P B; Chou, M J; Ooi, K T

    1999-02-01

    Repeated measures design for intra- and interrater reliability. To determine the intra- and interrater reliability of the lumbar spine range of motion measured with a dual inclinometer, and the thoracolumbar spine range of motion measured with a long-arm goniometer, as recommended in the American Medical Association Guides. The American Medical Association Guides (2nd and 4th editions) recommend using measurements of thoracolumbar and lumbar range of movement, respectively, to estimate the percentage of permanent impairment in patients with chronic low back pain. However, the reliability of this method of estimating impairment has not been determined. In all, 34 subjects participated in the study, 21 women with a mean age of 40.1 years (SD, +/- 11.1) and 13 men with a mean age of 47.7 years (SD, +/- 12.1). Measures of thoracolumbar flexion, extension, lateral flexion, and rotation were obtained with a long-arm goniometer. Lumbar flexion, extension, and lateral flexion were measured with a dual inclinometer. Measurements were taken by two examiners on one occasion and by one examiner on two occasions approximately 1 week apart. The results showed poor intra- and interrater reliability for all measurements taken with both instruments. Measurement error expressed in degrees showed that measurements taken by different raters exhibited systematic as well as random differences. As a result, subjects measured by two different examiners on the same day, with either instrument, could give impairment ratings ranging between 0% and 18% of the whole person (excluding rotation), in which percentage impairment is calculated using the average range of motion and the average systematic and random error in degrees for the group for each movement (flexion, extension, and lateral flexion). The poor reliability of the American Medical Association Guides' spinal range of motion model can result in marked variation in the percentage of whole-body impairment. These findings have

  17. Thermodependence of growth and enzymatic activities implicated in pathogenicity of two Erwinia carotovora subspecies (Pectobacterium spp.).

    Science.gov (United States)

    Smadja, Bruno; Latour, Xavier; Trigui, Sameh; Burini, Jean François; Chevalier, Sylvie; Orange, Nicole

    2004-01-01

    Erwinia carotovora subsp. atroseptica and Erwinia carotovora subsp. carotovora can cause substantial damage to economically important plant crops and stored products. The occurrence of the disease and the scale of the damage are temperature dependent. Disease development consists first of active multiplication of the bacteria in the infection area and then production of numerous extracellular enzymes. We investigated the effects of various temperatures on these two steps. We assayed the specific growth rate and the pectate lyase and protease activities for eight strains belonging to E. carotovora subsp. atroseptica and E. carotovora subsp. carotovora in vitro. The temperature effect on growth rate and on pectate lyase activity is different for the two subspecies, but protease activity appears to be similarly thermoregulated. Our results are in agreement with ecological data implicating E. carotovora subsp. atroseptica in disease when the temperature is below 20 degrees C. The optimal temperature for pathogenicity appears to be different from the optimal growth temperature but seems to be a compromise between this temperature and temperatures at which lytic activities are maximal.

  18. Microprocessor hardware reliability

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R I

    1982-01-01

    Microprocessor-based technology has had an impact in nearly every area of industrial electronics and many applications have important safety implications. Microprocessors are being used for the monitoring and control of hazardous processes in the chemical, oil and power generation industries, for the control and instrumentation of aircraft and other transport systems and for the control of industrial machinery. Even in the field of nuclear reactor protection, where designers are particularly conservative, microprocessors are used to implement certain safety functions and may play increasingly important roles in protection systems in the future. Where microprocessors are simply replacing conventional hard-wired control and instrumentation systems no new hazards are created by their use. In the field of robotics, however, the microprocessor has opened up a totally new technology and with it has created possible new and as yet unknown hazards. The paper discusses some of the design and manufacturing techniques which may be used to enhance the reliability of microprocessor based systems and examines the available reliability data on lsi/vlsi microcircuits. 12 references.

  19. Population growth and its implications

    Directory of Open Access Journals (Sweden)

    Badii, M. H.

    2005-01-01

    Full Text Available Human populations have grown at an unprecedented rate over the past three centuries. By 2001, the world population stood at 6.2 billion people. If the current trend of 1.4 % per year persists, the population will double in 51years. Most of that growth will occur in the less developed countries of Asia, Africa, and Latin America. There is a serious concern that the number of humans in the world and our impact on the environment will overload the life support systems of the earth. The crude birth rate is the number of births in a year divided by the average population. A more accurate measure of growth is the general fertility rate, which takes into account the age structure and fecundity of the population. The crude birth rate minus the crude death rate gives the rate of natural increase. When this rate reaches a level at which people are just replacing themselves, zero population growth is achieved. In the more highly developed countries of the world, growth has slowed are even reversed in recent years so that without immigration from other areas, population would be declining. The change from high birth and death rates that accompanies in industrialization is called a demographic transition. Many developing nations have already begun this transition. Death rates have fallen, but birth rates remain high. Some demographers believe that as infant mortality drops and economic development progresses so that people in these countries can be sure of secure future, they will complete the transition to a stable population or a high standard living. While larger populations bring many problems, they also may be a valuable resource of energy, intelligence, and enterprise that will make it possible to overcome resource limitation problems. A social just view argues that a more equitable distribution of wealth might reduce both excess population growth and environmental degradation. We have many more options now for controlling fertility than were available

  20. Reliability of EUCLIDIAN: An autonomous robotic system for image-guided prostate brachytherapy

    International Nuclear Information System (INIS)

    Podder, Tarun K.; Buzurovic, Ivan; Huang Ke; Showalter, Timothy; Dicker, Adam P.; Yu, Yan

    2011-01-01

    Purpose: Recently, several robotic systems have been developed to perform accurate and consistent image-guided brachytherapy. Before introducing a new device into clinical operations, it is important to assess the reliability and mean time before failure (MTBF) of the system. In this article, the authors present the preclinical evaluation and analysis of the reliability and MTBF of an autonomous robotic system, which is developed for prostate seed implantation. Methods: The authors have considered three steps that are important in reliability growth analysis. These steps are: Identification and isolation of failures, classification of failures, and trend analysis. For any one-of-a-kind product, the reliability enhancement is accomplished through test-fix-test. The authors have used failure mode and effect analysis for collection and analysis of reliability data by identifying and categorizing the failure modes. Failures were classified according to severity. Failures that occurred during the operation of this robotic system were considered as nonhomogenous Poisson process. The failure occurrence trend was analyzed using Laplace test. For analyzing and predicting reliability growth, commonly used and widely accepted models, Duane's model and the Army Material Systems Analysis Activity, i.e., Crow's model, were applied. The MTBF was used as an important measure for assessing the system's reliability. Results: During preclinical testing, 3196 seeds (in 53 test cases) were deposited autonomously by the robot and 14 critical failures were encountered. The majority of the failures occurred during the first few cases. The distribution of failures followed Duane's postulation as well as Crow's postulation of reliability growth. The Laplace test index was -3.82 (<0), indicating a significant trend in failure data, and the failure intervals lengthened gradually. The continuous increase in the failure occurrence interval suggested a trend toward improved reliability. The MTBF

  1. Reliability of EUCLIDIAN: An autonomous robotic system for image-guided prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K.; Buzurovic, Ivan; Huang Ke; Showalter, Timothy; Dicker, Adam P.; Yu, Yan [Department of Radiation Oncology, Kimmel Cancer Center (NCI-designated), Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States)

    2011-01-15

    Purpose: Recently, several robotic systems have been developed to perform accurate and consistent image-guided brachytherapy. Before introducing a new device into clinical operations, it is important to assess the reliability and mean time before failure (MTBF) of the system. In this article, the authors present the preclinical evaluation and analysis of the reliability and MTBF of an autonomous robotic system, which is developed for prostate seed implantation. Methods: The authors have considered three steps that are important in reliability growth analysis. These steps are: Identification and isolation of failures, classification of failures, and trend analysis. For any one-of-a-kind product, the reliability enhancement is accomplished through test-fix-test. The authors have used failure mode and effect analysis for collection and analysis of reliability data by identifying and categorizing the failure modes. Failures were classified according to severity. Failures that occurred during the operation of this robotic system were considered as nonhomogenous Poisson process. The failure occurrence trend was analyzed using Laplace test. For analyzing and predicting reliability growth, commonly used and widely accepted models, Duane's model and the Army Material Systems Analysis Activity, i.e., Crow's model, were applied. The MTBF was used as an important measure for assessing the system's reliability. Results: During preclinical testing, 3196 seeds (in 53 test cases) were deposited autonomously by the robot and 14 critical failures were encountered. The majority of the failures occurred during the first few cases. The distribution of failures followed Duane's postulation as well as Crow's postulation of reliability growth. The Laplace test index was -3.82 (<0), indicating a significant trend in failure data, and the failure intervals lengthened gradually. The continuous increase in the failure occurrence interval suggested a trend toward

  2. Understanding and predicting metallic whisker growth and its effects on reliability : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Michael, Joseph Richard; Grant, Richard P.; Rodriguez, Mark Andrew; Pillars, Jamin; Susan, Donald Francis; McKenzie, Bonnie Beth; Yelton, William Graham

    2012-01-01

    Tin (Sn) whiskers are conductive Sn filaments that grow from Sn-plated surfaces, such as surface finishes on electronic packages. The phenomenon of Sn whiskering has become a concern in recent years due to requirements for lead (Pb)-free soldering and surface finishes in commercial electronics. Pure Sn finishes are more prone to whisker growth than their Sn-Pb counterparts and high profile failures due to whisker formation (causing short circuits) in space applications have been documented. At Sandia, Sn whiskers are of interest due to increased use of Pb-free commercial off-the-shelf (COTS) parts and possible future requirements for Pb-free solders and surface finishes in high-reliability microelectronics. Lead-free solders and surface finishes are currently being used or considered for several Sandia applications. Despite the long history of Sn whisker research and the recently renewed interest in this topic, a comprehensive understanding of whisker growth remains elusive. This report describes recent research on characterization of Sn whiskers with the aim of understanding the underlying whisker growth mechanism(s). The report is divided into four sections and an Appendix. In Section 1, the Sn plating process is summarized. Specifically, the Sn plating parameters that were successful in producing samples with whiskers will be reviewed. In Section 2, the scanning electron microscopy (SEM) of Sn whiskers and time-lapse SEM studies of whisker growth will be discussed. This discussion includes the characterization of straight as well as kinked whiskers. In Section 3, a detailed discussion is given of SEM/EBSD (electron backscatter diffraction) techniques developed to determine the crystallography of Sn whiskers. In Section 4, these SEM/EBSD methods are employed to determine the crystallography of Sn whiskers, with a statistically significant number of whiskers analyzed. This is the largest study of Sn whisker crystallography ever reported. This section includes a

  3. System reliability of corroding pipelines

    International Nuclear Information System (INIS)

    Zhou Wenxing

    2010-01-01

    A methodology is presented in this paper to evaluate the time-dependent system reliability of a pipeline segment that contains multiple active corrosion defects and is subjected to stochastic internal pressure loading. The pipeline segment is modeled as a series system with three distinctive failure modes due to corrosion, namely small leak, large leak and rupture. The internal pressure is characterized as a simple discrete stochastic process that consists of a sequence of independent and identically distributed random variables each acting over a period of one year. The magnitude of a given sequence follows the annual maximum pressure distribution. The methodology is illustrated through a hypothetical example. Furthermore, the impact of the spatial variability of the pressure loading and pipe resistances associated with different defects on the system reliability is investigated. The analysis results suggest that the spatial variability of pipe properties has a negligible impact on the system reliability. On the other hand, the spatial variability of the internal pressure, initial defect sizes and defect growth rates can have a significant impact on the system reliability.

  4. A Method of Nuclear Software Reliability Estimation

    International Nuclear Information System (INIS)

    Park, Gee Yong; Eom, Heung Seop; Cheon, Se Woo; Jang, Seung Cheol

    2011-01-01

    A method on estimating software reliability for nuclear safety software is proposed. This method is based on the software reliability growth model (SRGM) where the behavior of software failure is assumed to follow the non-homogeneous Poisson process. Several modeling schemes are presented in order to estimate and predict more precisely the number of software defects based on a few of software failure data. The Bayesian statistical inference is employed to estimate the model parameters by incorporating the software test cases into the model. It is identified that this method is capable of accurately estimating the remaining number of software defects which are on-demand type directly affecting safety trip functions. The software reliability can be estimated from a model equation and one method of obtaining the software reliability is proposed

  5. Solder joint technology materials, properties, and reliability

    CERN Document Server

    Tu, King-Ning

    2007-01-01

    Solder joints are ubiquitous in electronic consumer products. The European Union has a directive to ban the use of Pb-based solders in these products on July 1st, 2006. There is an urgent need for an increase in the research and development of Pb-free solders in electronic manufacturing. For example, spontaneous Sn whisker growth and electromigration induced failure in solder joints are serious issues. These reliability issues are quite complicated due to the combined effect of electrical, mechanical, chemical, and thermal forces on solder joints. To improve solder joint reliability, the science of solder joint behavior under various driving forces must be understood. In this book, the advanced materials reliability issues related to copper-tin reaction and electromigration in solder joints are emphasized and methods to prevent these reliability problems are discussed.

  6. Mudcake growth: Model and implications

    KAUST Repository

    Liu, Q.; Santamarina, Carlos

    2017-01-01

    cementing, and to prevent partial differential sticking. We developed a robust mud cake growth model for water-based mud based on wide stress-range constitutive equations within a Lagrangian reference system to avoid non-natural moving boundary solutions

  7. Test-Retest Reliability and Minimal Detectable Change of Randomized Dichotic Digits in Learning-Disabled Children: Implications for Dichotic Listening Training.

    Science.gov (United States)

    Mahdavi, Mohammad Ebrahim; Pourbakht, Akram; Parand, Akram; Jalaie, Shohreh

    2018-03-01

    children were 1.46 and 1.44% for the right ear and 4.68 and 5.47% for the left ear. SEM and SEM% of the ear scores in LD children were 4.55 and 5.88% for the right ear to 7.56 and 12.81% for the left ear. MDC and MDC% of the ear scores in TA children varied from 4.03 and 3.99% for the right ear to 12.93 and 15.13% for the left ear. MDC and MDC% of the ear scores in LD children varied from 12.57 and 16.25% for the right ear to 20.89 and 35.39% for the left ear. The LD children indicated test-retest relative reliability as high as TA children in the ear scores measured by PRDDT. However, within-subject variations of the ear scores calculated by indices of absolute reliability were considerably higher in LD children versus TA children. The results of the current study could have implications for detecting real training-related changes in the ear scores. American Academy of Audiology

  8. Electromigration-induced Plasticity: Texture Correlation and Implications for Reliability Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Budiman, A.S.; Besser, P.R.; Hau-Riege, C.S.; Marathe, A.; Joo, Y.-C.; Tamura, N.; Patel, J.R.; Nix, W.D.

    2008-05-29

    Plastic behavior has previously been observed in metallic interconnects undergoing high current density electromigration (EM) loading. In this study of Cu interconnects, using the synchrotron technique of white beam X-ray microdiffraction, we have further found preliminary evidence of a texture correlation. In lines with strong (111) textures, the extent of plastic deformation is found to be relatively large compared to that of weaker textures. We suggest that this strong (111) texture may lead to an extra path of mass transport in addition to the dominant interface diffusion in Cu EM. When this extra mass transport begins to affect the overall transport process, then the effective diffusivity, D{sub eff}, of the EM process is expected to deviate from that of interface diffusion only. This would have fundamental implications. We have some preliminary observations that this might be the case, and we report its implications for EM lifetime assessment in this manuscript.

  9. Intraskeletal histovariability, allometric growth patterns, and their functional implications in bird-like dinosaurs.

    Science.gov (United States)

    Prondvai, Edina; Godefroit, Pascal; Adriaens, Dominique; Hu, Dong-Yu

    2018-01-10

    With their elongated forelimbs and variable aerial skills, paravian dinosaurs, a clade also comprising modern birds, are in the hotspot of vertebrate evolutionary research. Inferences on the early evolution of flight largely rely on bone and feather morphology, while osteohistological traits are usually studied to explore life-history characteristics. By sampling and comparing multiple homologous fore- and hind limb elements, we integrate for the first time qualitative and quantitative osteohistological approaches to get insight into the intraskeletal growth dynamics and their functional implications in five paravian dinosaur taxa, Anchiornis, Aurornis, Eosinopteryx, Serikornis, and Jeholornis. Our qualitative assessment implies a considerable diversity in allometric/isometric growth patterns among these paravians. Quantitative analyses show that neither taxa nor homologous elements have characteristic histology, and that ontogenetic stage, element size and the newly introduced relative element precocity only partially explain the diaphyseal histovariability. Still, Jeholornis, the only avialan studied here, is histologically distinct from all other specimens in the multivariate visualizations raising the hypothesis that its bone tissue characteristics may be related to its superior aerial capabilities compared to the non-avialan paravians. Our results warrant further research on the osteohistological correlates of flight and developmental strategies in birds and bird-like dinosaurs.

  10. Reliability of cervical vertebral maturation staging.

    Science.gov (United States)

    Rainey, Billie-Jean; Burnside, Girvan; Harrison, Jayne E

    2016-07-01

    Growth and its prediction are important for the success of many orthodontic treatments. The aim of this study was to determine the reliability of the cervical vertebral maturation (CVM) method for the assessment of mandibular growth. A group of 20 orthodontic clinicians, inexperienced in CVM staging, was trained to use the improved version of the CVM method for the assessment of mandibular growth with a teaching program. They independently assessed 72 consecutive lateral cephalograms, taken at Liverpool University Dental Hospital, on 2 occasions. The cephalograms were presented in 2 different random orders and interspersed with 11 additional images for standardization. The intraobserver and interobserver agreement values were evaluated using the weighted kappa statistic. The intraobserver and interobserver agreement values were substantial (weighted kappa, 0.6-0.8). The overall intraobserver agreement was 0.70 (SE, 0.01), with average agreement of 89%. The interobserver agreement values were 0.68 (SE, 0.03) for phase 1 and 0.66 (SE, 0.03) for phase 2, with average interobserver agreement of 88%. The intraobserver and interobserver agreement values of classifying the vertebral stages with the CVM method were substantial. These findings demonstrate that this method of CVM classification is reproducible and reliable. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  11. Reliability studies of diagnostic methods in Indian traditional Ayurveda medicine: An overview

    Science.gov (United States)

    Kurande, Vrinda Hitendra; Waagepetersen, Rasmus; Toft, Egon; Prasad, Ramjee

    2013-01-01

    Recently, a need to develop supportive new scientific evidence for contemporary Ayurveda has emerged. One of the research objectives is an assessment of the reliability of diagnoses and treatment. Reliability is a quantitative measure of consistency. It is a crucial issue in classification (such as prakriti classification), method development (pulse diagnosis), quality assurance for diagnosis and treatment and in the conduct of clinical studies. Several reliability studies are conducted in western medicine. The investigation of the reliability of traditional Chinese, Japanese and Sasang medicine diagnoses is in the formative stage. However, reliability studies in Ayurveda are in the preliminary stage. In this paper, examples are provided to illustrate relevant concepts of reliability studies of diagnostic methods and their implication in practice, education, and training. An introduction to reliability estimates and different study designs and statistical analysis is given for future studies in Ayurveda. PMID:23930037

  12. Insulin-like growth factors act synergistically with basic fibroblast growth factor and nerve growth factor to promote chromaffin cell proliferation

    DEFF Research Database (Denmark)

    Frödin, M; Gammeltoft, S

    1994-01-01

    We have investigated the effects of insulin-like growth factors (IGFs), basic fibroblast growth factor (bFGF), and nerve growth factor (NGF) on DNA synthesis in cultured chromaffin cells from fetal, neonatal, and adult rats by using 5-bromo-2'-deoxyuridine (BrdUrd) pulse labeling for 24 or 48 h...... implications for improving the survival of chromaffin cell implants in diseased human brain....

  13. Field Programmable Gate Array Reliability Analysis Guidelines for Launch Vehicle Reliability Block Diagrams

    Science.gov (United States)

    Al Hassan, Mohammad; Britton, Paul; Hatfield, Glen Spencer; Novack, Steven D.

    2017-01-01

    Field Programmable Gate Arrays (FPGAs) integrated circuits (IC) are one of the key electronic components in today's sophisticated launch and space vehicle complex avionic systems, largely due to their superb reprogrammable and reconfigurable capabilities combined with relatively low non-recurring engineering costs (NRE) and short design cycle. Consequently, FPGAs are prevalent ICs in communication protocols and control signal commands. This paper will identify reliability concerns and high level guidelines to estimate FPGA total failure rates in a launch vehicle application. The paper will discuss hardware, hardware description language, and radiation induced failures. The hardware contribution of the approach accounts for physical failures of the IC. The hardware description language portion will discuss the high level FPGA programming languages and software/code reliability growth. The radiation portion will discuss FPGA susceptibility to space environment radiation.

  14. Interpretive reliability of two common MMPI-2 profiles

    Directory of Open Access Journals (Sweden)

    Mark A. Deskovitz

    2016-12-01

    Full Text Available Users of multi-scale tests like the MMPI-2 tend not to interpret scales one at a time in a way that would correspond to standard scale-level reliability information. Instead, clinicians integrate inferences from a multitude of scales simultaneously, producing a descriptive narrative that is thought to characterize the examinee. This study was an attempt to measure the reliability of such integrated interpretations using a q-sort research methodology. Participants were 20 MMPI-2 users who responded to E-mail solicitations on professional listservs and in personal emails. Each participant interpreted one of two common MMPI-2 profiles using a q-set of 100 statements designed for MMPI-2 interpretation. To measure the “interpretive reliability” of the MMPI-2 profile interpretations, q-sort descriptions were intercorrelated. Mean pairwise interpretive reliability was .39, lower than expected, and there was no significant difference in reliability between profiles. There was also not a significant difference between within-profile and cross-profile correlations. Q-set item analysis was conducted to determine which individual statements had the most impact on interpretive reliability. Although sampling in this study was limited, implications for the field reliability of MMPI-2 interpretation are sobering.

  15. The reliability paradox: Why robust cognitive tasks do not produce reliable individual differences.

    Science.gov (United States)

    Hedge, Craig; Powell, Georgina; Sumner, Petroc

    2017-07-19

    Individual differences in cognitive paradigms are increasingly employed to relate cognition to brain structure, chemistry, and function. However, such efforts are often unfruitful, even with the most well established tasks. Here we offer an explanation for failures in the application of robust cognitive paradigms to the study of individual differences. Experimental effects become well established - and thus those tasks become popular - when between-subject variability is low. However, low between-subject variability causes low reliability for individual differences, destroying replicable correlations with other factors and potentially undermining published conclusions drawn from correlational relationships. Though these statistical issues have a long history in psychology, they are widely overlooked in cognitive psychology and neuroscience today. In three studies, we assessed test-retest reliability of seven classic tasks: Eriksen Flanker, Stroop, stop-signal, go/no-go, Posner cueing, Navon, and Spatial-Numerical Association of Response Code (SNARC). Reliabilities ranged from 0 to .82, being surprisingly low for most tasks given their common use. As we predicted, this emerged from low variance between individuals rather than high measurement variance. In other words, the very reason such tasks produce robust and easily replicable experimental effects - low between-participant variability - makes their use as correlational tools problematic. We demonstrate that taking such reliability estimates into account has the potential to qualitatively change theoretical conclusions. The implications of our findings are that well-established approaches in experimental psychology and neuropsychology may not directly translate to the study of individual differences in brain structure, chemistry, and function, and alternative metrics may be required.

  16. Insulin-like growth factors and pancreas beta cells.

    NARCIS (Netherlands)

    Haeften, T.W. van; Twickler, M.

    2004-01-01

    Abstract Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their

  17. Insulin-like growth factors and pancreas beta cells

    NARCIS (Netherlands)

    van Haeften, T. W.; Twickler, TB

    Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their signalling

  18. Insulin-like growth factors and pancreas beta cells

    NARCIS (Netherlands)

    van Haeften, T. W.; Twickler, Th B.

    2004-01-01

    Abstract Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their

  19. Training and Maintaining System-Wide Reliability in Outcome Management.

    Science.gov (United States)

    Barwick, Melanie A; Urajnik, Diana J; Moore, Julia E

    2014-01-01

    The Child and Adolescent Functional Assessment Scale (CAFAS) is widely used for outcome management, for providing real time client and program level data, and the monitoring of evidence-based practices. Methods of reliability training and the assessment of rater drift are critical for service decision-making within organizations and systems of care. We assessed two approaches for CAFAS training: external technical assistance and internal technical assistance. To this end, we sampled 315 practitioners trained by external technical assistance approach from 2,344 Ontario practitioners who had achieved reliability on the CAFAS. To assess the internal technical assistance approach as a reliable alternative training method, 140 practitioners trained internally were selected from the same pool of certified raters. Reliabilities were high for both practitioners trained by external technical assistance and internal technical assistance approaches (.909-.995, .915-.997, respectively). 1 and 3-year estimates showed some drift on several scales. High and consistent reliabilities over time and training method has implications for CAFAS training of behavioral health care practitioners, and the maintenance of CAFAS as a global outcome management tool in systems of care.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kerscher, W.J. III [Delphi Energy and Engine Management Systems, Flint, MI (United States); Booker, J.M.; Bement, T.R.; Meyer, M.A. [Los Alamos National Lab., NM (United States)

    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.

  1. SGHWR fuel performance, safety and reliability

    International Nuclear Information System (INIS)

    Pickman, D.O.; Inglis, G.H.

    1977-05-01

    The design principles involved in fuel pins and elements need to take account of the sometimes conflicting requirements of safety and reliability. The principal factors involved in this optimisation are discussed and it is shown from fuel irradiation experience in the Winfrith SGHWR that the necessary bias towards safety has not resulted in a reliability level lower than that shown by other successful water reactor designs. Reliability has important economic implications. By a detailed evaluation of SGHWR fuel defects it is shown that very few defects can be shown to be related to design, rating, or burn-up. This demonstrates that economic aspects have not over-ridden necessary criteria that most be met to achieve the desirable reliability level. It is possible that large scale experience on SGHWR fuel may eventually demonstrate that the balance is too much in favour of reliability and consideration may be given to whether design changes favouring economy could be achieved without compromising safety. The safety criteria applied to SGHWR fuel are designed to avoid any possibility of a temperature runaway in any credible accident situation. the philosophy and supporting experimental work programme are outlines and the fuel design features which particularly contribute to maximising safety margins are outlined. Reference is made to the new 60-pin fuel element to be used in the commercial SGHWRs and to its comparison in design and performance aspects with the 36-pin element that has been used to date in the Winfrith SGHWR. (author)

  2. NASA Applications and Lessons Learned in Reliability Engineering

    Science.gov (United States)

    Safie, Fayssal M.; Fuller, Raymond P.

    2011-01-01

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

  3. The impact of forest thinning on the reliability of water supply in central Arizona.

    Directory of Open Access Journals (Sweden)

    Silvio Simonit

    Full Text Available Economic growth in Central Arizona, as in other semiarid systems characterized by low and variable rainfall, has historically depended on the effectiveness of strategies to manage water supply risks. Traditionally, the management of supply risks includes three elements: hard infrastructures, landscape management within the watershed, and a supporting set of institutions of which water markets are frequently the most important. In this paper we model the interactions between these elements. A forest restoration initiative in Central Arizona (the Four Forest Restoration Initiative, or 4FRI will result in thinning of ponderosa pine forests in the upper watershed, with potential implications for both sedimentation rates and water delivery to reservoirs. Specifically, we model the net effect of ponderosa pine forest thinning across the Salt and Verde River watersheds on the reliability and cost of water supply to the Phoenix metropolitan area. We conclude that the sediment impacts of forest thinning (up to 50% of canopy cover are unlikely to compromise the reliability of the reservoir system while thinning has the potential to increase annual water supply by 8%. This represents an estimated net present value of surface water storage of $104 million, considering both water consumption and hydropower generation.

  4. The Impact of Forest Thinning on the Reliability of Water Supply in Central Arizona

    Science.gov (United States)

    Simonit, Silvio; Connors, John P.; Yoo, James; Kinzig, Ann; Perrings, Charles

    2015-01-01

    Economic growth in Central Arizona, as in other semiarid systems characterized by low and variable rainfall, has historically depended on the effectiveness of strategies to manage water supply risks. Traditionally, the management of supply risks includes three elements: hard infrastructures, landscape management within the watershed, and a supporting set of institutions of which water markets are frequently the most important. In this paper we model the interactions between these elements. A forest restoration initiative in Central Arizona (the Four Forest Restoration Initiative, or 4FRI) will result in thinning of ponderosa pine forests in the upper watershed, with potential implications for both sedimentation rates and water delivery to reservoirs. Specifically, we model the net effect of ponderosa pine forest thinning across the Salt and Verde River watersheds on the reliability and cost of water supply to the Phoenix metropolitan area. We conclude that the sediment impacts of forest thinning (up to 50% of canopy cover) are unlikely to compromise the reliability of the reservoir system while thinning has the potential to increase annual water supply by 8%. This represents an estimated net present value of surface water storage of $104 million, considering both water consumption and hydropower generation. PMID:25835003

  5. The reliability of routine anthropometric data collected by health workers: a cross-sectional study.

    Science.gov (United States)

    Johnson, William; Cameron, Noël; Dickson, Peter; Emsley, Stuart; Raynor, Pauline; Seymour, Claire; Wright, John

    2009-03-01

    Reliable data on child growth is a prerequisite for monitoring and improving child health. Despite the extensive resources invested in recording anthropometry, there has been little research into the reliability of these data. If these measurements are unreliable growth may be misreported, and health problems may go undetected. To assess the reliability of routine infant growth data, following anthropometric training of health workers responsible for collecting these data, in Bradford, UK. To determine whether being observed by an external administrator influenced reliability. A test-retest design was used. All health workers (n=192) responsible for growth monitoring in Bradford were included in the study, of which 36.5% (n=70) had complete data. Following training in basic anthropometry all health workers were asked to complete a test-retest study, using infants aged 0-2 years. Health workers took two recordings of weight, length, head circumference, and abdominal circumferences on five infants. A peer health worker recorded a third set of measurements on each infant. Twenty-two individuals were selected to be observed by an external administrator during data collection. Technical error of measurements (TEMs) were produced to assess intra-observer and inter-observer reliability. Differences between groups were tested to determine whether external observation influences reliability. None of the TEMs were excessively large, and coefficients of reliability ranged from 0.96 to 1.00. All intra-observer and inter-observer TEMs for the observed group were larger than those for the non-observed group. For example, the observed group's intra-observer TEMs for weight, length, abdominal circumference, and head circumference (46.18 g, 0.60 cm, 0.65 cm, 0.47 cm) were larger than the non-observed group's TEMS (9.14 g, 0.35 cm, 0.34 cm, 0.19 cm). TEMs for weight, abdominal circumference, and head circumference were significantly larger for the observed group, compared to the non

  6. Advanced control rooms and crew performance issues: Implications for human reliability

    International Nuclear Information System (INIS)

    O'Hara, J.M.; Hall, R.E.

    1991-01-01

    Recent trends in advanced control room (ACR) design are considered with respect to their impact on human performance. It is concluded that potentially negative influences exist, however, a variety of factors make it difficult to model, analyze, and quantify these effects for human reliability analyses (HRAs)

  7. Vascular endothelial growth factor is upregulated by l-dopa in the parkinsonian brain: implications for the development of dyskinesia

    Science.gov (United States)

    Francardo, Veronica; Lindgren, Hanna S.; Sillivan, Stephanie E.; O’Sullivan, Sean S.; Luksik, Andrew S.; Vassoler, Fair M.; Lees, Andrew J.; Konradi, Christine

    2011-01-01

    Angiogenesis and increased permeability of the blood–brain barrier have been reported to occur in animal models of Parkinson’s disease and l-dopa-induced dyskinesia, but the significance of these phenomena has remained unclear. Using a validated rat model of l-dopa-induced dyskinesia, this study demonstrates that chronic treatment with l-dopa dose dependently induces the expression of vascular endothelial growth factor in the basal ganglia nuclei. Vascular endothelial growth factor was abundantly expressed in astrocytes and astrocytic processes in the proximity of blood vessels. When co-administered with l-dopa, a small molecule inhibitor of vascular endothelial growth factor signalling significantly attenuated the development of dyskinesia and completely blocked the angiogenic response and associated increase in blood–brain barrier permeability induced by the treatment. The occurrence of angiogenesis and vascular endothelial growth factor upregulation was verified in post-mortem basal ganglia tissue from patients with Parkinson’s disease with a history of dyskinesia, who exhibited increased microvascular density, microvascular nestin expression and an upregulation of vascular endothelial growth factor messenger ribonucleic acid. These congruent findings in the rat model and human patients indicate that vascular endothelial growth factor is implicated in the pathophysiology of l-dopa-induced dyskinesia and emphasize an involvement of the microvascular compartment in the adverse effects of l-dopa pharmacotherapy in Parkinson’s disease. PMID:21771855

  8. Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change.

    Science.gov (United States)

    Ong, Joyce Jia Lin; Rountrey, Adam Nicholas; Meeuwig, Jessica Jane; Newman, Stephen John; Zinke, Jens; Meekan, Mark Gregory

    2015-06-08

    Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations.

  9. Specific protein supplementation using soya, casein or whey differentially affects regional gut growth and luminal growth factor bioactivity in rats; implications for the treatment of gut injury and stimulating repair.

    Science.gov (United States)

    Marchbank, Tania; Mandir, Nikki; Calnan, Denis; Goodlad, Robert A; Podas, Theo; Playford, Raymond J

    2018-01-24

    Modulation of regional growth within specific segments of the bowel may have clinical value for several gastrointestinal conditions. We therefore examined the effects of different dietary protein sources on regional gut growth and luminal growth factor bioactivity as potential therapies. Rats were fed for 14 days on isonitrogenous and isocaloric diets comprising elemental diet (ED) alone (which is known to cause gut atrophy), ED supplemented with casein or whey or a soya protein-rich feed. Effects on regional gut growth and intraluminal growth factor activity were then determined. Despite calorie intake being similar in all groups, soya rich feed caused 20% extra total body weight gain. Stomach weight was highest on soya and casein diets. Soya enhanced diet caused greatest increase in small intestinal weight and preserved luminal growth factor activity at levels sufficient to increase proliferation in vitro. Regional small intestinal proliferation was highest in proximal segment in ED fed animals whereas distal small intestine proliferation was greater in soya fed animals. Colonic weight and proliferation throughout the colon was higher in animals receiving soya or whey supplemented feeds. We conclude that specific protein supplementation with either soya, casein or whey may be beneficial to rest or increase growth in different regions of the bowel through mechanisms that include differentially affecting luminal growth factor bioactivity. These results have implications for targeting specific regions of the bowel for conditions such as Crohn's disease and chemotherapy.

  10. Reliability analysis techniques for the design engineer

    International Nuclear Information System (INIS)

    Corran, E.R.; Witt, H.H.

    1980-01-01

    A fault tree analysis package is described that eliminates most of the housekeeping tasks involved in proceeding from the initial construction of a fault tree to the final stage of presenting a reliability analysis in a safety report. It is suitable for designers with relatively little training in reliability analysis and computer operation. Users can rapidly investigate the reliability implications of various options at the design stage, and evolve a system which meets specified reliability objectives. Later independent review is thus unlikely to reveal major shortcomings necessitating modification and projects delays. The package operates interactively allowing the user to concentrate on the creative task of developing the system fault tree, which may be modified and displayed graphically. For preliminary analysis system data can be derived automatically from a generic data bank. As the analysis procedes improved estimates of critical failure rates and test and maintenance schedules can be inserted. The computations are standard, - identification of minimal cut-sets, estimation of reliability parameters, and ranking of the effect of the individual component failure modes and system failure modes on these parameters. The user can vary the fault trees and data on-line, and print selected data for preferred systems in a form suitable for inclusion in safety reports. A case history is given - that of HIFAR containment isolation system. (author)

  11. Analysis of information security reliability: A tutorial

    International Nuclear Information System (INIS)

    Kondakci, Suleyman

    2015-01-01

    This article presents a concise reliability analysis of network security abstracted from stochastic modeling, reliability, and queuing theories. Network security analysis is composed of threats, their impacts, and recovery of the failed systems. A unique framework with a collection of the key reliability models is presented here to guide the determination of the system reliability based on the strength of malicious acts and performance of the recovery processes. A unique model, called Attack-obstacle model, is also proposed here for analyzing systems with immunity growth features. Most computer science curricula do not contain courses in reliability modeling applicable to different areas of computer engineering. Hence, the topic of reliability analysis is often too diffuse to most computer engineers and researchers dealing with network security. This work is thus aimed at shedding some light on this issue, which can be useful in identifying models, their assumptions and practical parameters for estimating the reliability of threatened systems and for assessing the performance of recovery facilities. It can also be useful for the classification of processes and states regarding the reliability of information systems. Systems with stochastic behaviors undergoing queue operations and random state transitions can also benefit from the approaches presented here. - Highlights: • A concise survey and tutorial in model-based reliability analysis applicable to information security. • A framework of key modeling approaches for assessing reliability of networked systems. • The framework facilitates quantitative risk assessment tasks guided by stochastic modeling and queuing theory. • Evaluation of approaches and models for modeling threats, failures, impacts, and recovery analysis of information systems

  12. Overcoming some limitations of imprecise reliability models

    DEFF Research Database (Denmark)

    Kozine, Igor; Krymsky, Victor

    2011-01-01

    The application of imprecise reliability models is often hindered by the rapid growth in imprecision that occurs when many components constitute a system and by the fact that time to failure is bounded from above. The latter results in the necessity to explicitly introduce an upper bound on time ...

  13. Medical Tourism and Its Implication on Malaysia's Economic Growth

    OpenAIRE

    Tang, Chor Foon

    2015-01-01

    Policymakers in the developed and developing countries already heading toward medical tourism to stimulate economic growth. Nonetheless, the actual impact of medical tourism on economic growth remains ambiguous. Although medical tourism may spur economic growth via its impact on foreign currency earnings, investments, tax revenue, and employment opportunities, it may also leave numerous negative externalities that either direct or indirectly harmful the process of economic growth. Undeniably,...

  14. Analyzing the Tourism–Energy–Growth Nexus for the Top 10 Most-Visited Countries

    Directory of Open Access Journals (Sweden)

    Cem Işik

    2017-10-01

    Full Text Available By using the Emirmahmutoglu–Kose bootstrap Granger non-causality method, this study explores the directions of causality among tourist arrivals, tourism receipts, energy consumption and economic growth for the top 10 most-visited countries (France, the USA, Spain, China, Italy, Turkey, Germany, the United Kingdom, Russia, and Mexico in the world. This study finds a variety of causal directions between the pair of analyzed variables for each country and the panel. Since cross-sectional dependence exists across the top countries for the analyzed variables, the bootstrap Granger causality test that accounts for the mentioned issue in the estimation process presumably produces reliable and accurate outputs. Further results and policy implications are discussed in this empirical study.

  15. Reliable LED Lighting Technologies: Key Factors and Procurement Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Lynn; Arquit Niederberger, Anne

    2015-10-08

    Abstract— Lighting systems have the ability to transform the economic and educational infrastructure of disadvantaged communities, and eradicating “light poverty” has become one of the primary goals of the International Year of Light 2015. Solid-state lighting (SSL) technology, based on light-emitting diode (LED) light sources, has emerged as the next generation of lighting technology, with a current global market penetration of roughly 5%. This paper will report on recent research on understanding SSL lighting system reliability (failure modes, environmental stressors, electrical power quality); discuss the implications of SSL technology reliability for providing lighting services; and suggest practical approaches to ensure SSL reliability to benefit humanity. Among the key findings from this work is that LED sources can be extremely reliable, withstanding a broad range of environmental stresses without failure. Nonetheless, SSL lighting systems can have a negative impact on electrical power reliability, as well as on the affordability of lighting services, without attention to the quality of the accompanying power infrastructure. It is therefore critical to ensure that the performance of the power supply electronics used in lighting systems is matched to the quality of the power source, when evaluating energy efficient lighting choices.

  16. Chaos and reliability in balanced spiking networks with temporal drive.

    Science.gov (United States)

    Lajoie, Guillaume; Lin, Kevin K; Shea-Brown, Eric

    2013-05-01

    Biological information processing is often carried out by complex networks of interconnected dynamical units. A basic question about such networks is that of reliability: If the same signal is presented many times with the network in different initial states, will the system entrain to the signal in a repeatable way? Reliability is of particular interest in neuroscience, where large, complex networks of excitatory and inhibitory cells are ubiquitous. These networks are known to autonomously produce strongly chaotic dynamics-an obvious threat to reliability. Here, we show that such chaos persists in the presence of weak and strong stimuli, but that even in the presence of chaos, intermittent periods of highly reliable spiking often coexist with unreliable activity. We elucidate the local dynamical mechanisms involved in this intermittent reliability, and investigate the relationship between this phenomenon and certain time-dependent attractors arising from the dynamics. A conclusion is that chaotic dynamics do not have to be an obstacle to precise spike responses, a fact with implications for signal coding in large networks.

  17. Implications of U.S. electricity deregulation

    International Nuclear Information System (INIS)

    Gottfried, D.A.

    1997-01-01

    This article is a concise summary of the potential impacts of electric utility deregulation, including the resolution of stranded costs, impact on electricity rates, reformation of utilities, and reshuffling of the nation's fuel portfolio. The national and state implications of the deregulation of the electricity industry are monumental and overwhelming. The implications occur on many fronts, including monetary, quality, reliability, and environmental issues. Many significant changes will occur as a result--some will be positive and others may be more disturbing

  18. Generating project value through design for reliability: on the development and implementation of a potential value framework

    OpenAIRE

    Woods, K. B. W.

    2007-01-01

    The current trend to economically exploit deepwater hydrocarbon reserves is to reduce the capital expenditure; accomplished by deploying subsea equipment. The financial benefit afforded is offset by the risk of high operational costs associated with failure. Recognition of the life cycle cost implications of subsea reliability have led to the development of the reliability strategy. This strategy adopts a risk based approach to design for reliability where only analyses (and th...

  19. Clinical implications for Vascular Endothelial Growth Factor in the lung: friend or foe?

    Directory of Open Access Journals (Sweden)

    Gourgoulianis Konstantinos I

    2006-10-01

    Full Text Available Abstract Vascular endothelial growth factor (VEGF is a potent mediator of angiogenesis which has multiple effects in lung development and physiology. VEGF is expressed in several parts of the lung and the pleura while it has been shown that changes in its expression play a significant role in the pathophysiology of some of the most common respiratory disorders, such as acute lung injury, asthma, chronic obstructive pulmonary disease, obstructive sleep apnea, idiopathic pulmonary fibrosis, pulmonary hypertension, pleural disease, and lung cancer. However, the exact role of VEGF in the lung is not clear yet, as there is contradictory evidence that suggests either a protective or a harmful role. VEGF seems to interfere in a different manner, depending on its amount, the location, and the underlying pathologic process in lung tissue. The lack of VEGF in some disease entities may provide implications for its substitution, whereas its overexpression in other lung disorders has led to interventions for the attenuation of its action. Many efforts have been made in order to regulate the expression of VEGF and anti-VEGF antibodies are already in use for the management of lung cancer. Further research is still needed for the complete understanding of the exact role of VEGF in health and disease, in order to take advantage of its benefits and avoid its adverse effects. The scope of the present review is to summarize from a clinical point of view the changes in VEGF expression in several disorders of the respiratory system and focus on its diagnostic and therapeutic implications.

  20. Spatial reliability analysis of a wind turbine blade cross section subjected to multi-axial extreme loading

    DEFF Research Database (Denmark)

    Dimitrov, Nikolay Krasimirov; Bitsche, Robert; Blasques, José Pedro Albergaria Amaral

    2017-01-01

    This paper presents a methodology for structural reliability analysis of wind turbine blades. The study introduces several novel elements by taking into account loading direction using a multiaxial probabilistic load model, considering random material strength, spatial correlation between material...... properties, progressive material failure, and system reliability effects. An example analysis of reliability against material failure is demonstrated for a blade cross section. Based on the study we discuss the implications of using a system reliability approach, the effect of spatial correlation length......, type of material degradation algorithm, and reliability methods on the system failure probability, as well as the main factors that have an influence on the reliability. (C) 2017 Elsevier Ltd. All rights reserved....

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

    Science.gov (United States)

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

    2015-02-01

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

  2. High reliability flow system - an assessment of pump reliability and optimisation of the number of pumps

    International Nuclear Information System (INIS)

    Butterfield, J.M.

    1981-01-01

    A system is considered where a number of pumps operate in parallel. Normally, all pumps operate, driven by main motors fed from the grid. Each pump has a pony motor fed from an individual battery supply. Each pony motor is normally running, but not engaged to the pump shaft. On demand, e.g. failure of grid supplies, each pony motor is designed to clutch-in automatically when the pump speed falls to a specified value. The probability of all the pony motors failing to clutch-in on demand must be demonstrated with 95% confidence to be less than 10 -8 per demand. This assessment considers how the required reliability of pony motor drives might be demonstrated in practice and the implications on choice of the number of pumps at the design stage. The assessment recognises that not only must the system prove to be extremely reliable, but that demonstration that reliability is adequate must be done during plant commissioning, with practical limits on the amount of testing performed. It is concluded that a minimum of eight pony motors should be provided, eight pumps each with one pony motor (preferred) or five pumps each with two independent pony motors. A minimum of two diverse pony motor systems should be provided. (author)

  3. Mudcake growth: Model and implications

    KAUST Repository

    Liu, Q.

    2017-12-15

    Oil and gas account for 60% of the world\\'s energy consumption. Drilling muds that are used to advance oil and gas wells must be engineered to avoid wellbore integrity problems associated with mud cake formation, to favor cake erosion during cementing, and to prevent partial differential sticking. We developed a robust mud cake growth model for water-based mud based on wide stress-range constitutive equations within a Lagrangian reference system to avoid non-natural moving boundary solutions. The comprehensive mud cake growth model readily accommodates environmental factors (e.g., temperature, pH, and ionic concentration) and defines the yield stress distribution for displacement-erosion analyses. Results show that the mud cake thickness is more sensitive to time than to filtration pressure, therefore, time controls the non-uniform distribution of mudcake thickness during drilling. Long filtration time, high permeability, high salinity, high in-situ temperature and low viscosity exacerbate fluid loss and give rise to thick filter cakes. The analysis of residual cake thickness during cement displacement must take into account the effective stress dependent mudcake formation and the time-dependent mud thixotropy. Thixotropy dominates the mud yield stress at high void ratios, e.g. e > 20. The offsetting force that causes differential pressure sticking increases sub-linearly as a power function of the still-time.

  4. Based on Weibull Information Fusion Analysis Semiconductors Quality the Key Technology of Manufacturing Execution Systems Reliability

    Science.gov (United States)

    Huang, Zhi-Hui; Tang, Ying-Chun; Dai, Kai

    2016-05-01

    Semiconductor materials and Product qualified rate are directly related to the manufacturing costs and survival of the enterprise. Application a dynamic reliability growth analysis method studies manufacturing execution system reliability growth to improve product quality. Refer to classical Duane model assumptions and tracking growth forecasts the TGP programming model, through the failure data, established the Weibull distribution model. Combining with the median rank of average rank method, through linear regression and least squares estimation method, match respectively weibull information fusion reliability growth curve. This assumption model overcome Duane model a weakness which is MTBF point estimation accuracy is not high, through the analysis of the failure data show that the method is an instance of the test and evaluation modeling process are basically identical. Median rank in the statistics is used to determine the method of random variable distribution function, which is a good way to solve the problem of complex systems such as the limited sample size. Therefore this method has great engineering application value.

  5. PUBLIC GOODS, CORRUPTION AND GROWTH???

    OpenAIRE

    Ratbek Dzhumashev

    2006-01-01

    In this paper, we analyse implications of corruption on growth. We extend existing growth models by incorporating ubiquitous corruption as a by-product of the public sector. Corruption affects both taxation and public good provision, and therefore causes income redistribution and inefficiencies in the public sector. These effects of corruption lead to lower growth through distortions of investment incentives and resources allocation.

  6. Product reliability and thin-film photovoltaics

    Science.gov (United States)

    Gaston, Ryan; Feist, Rebekah; Yeung, Simon; Hus, Mike; Bernius, Mark; Langlois, Marc; Bury, Scott; Granata, Jennifer; Quintana, Michael; Carlson, Carl; Sarakakis, Georgios; Ogden, Douglas; Mettas, Adamantios

    2009-08-01

    Despite significant growth in photovoltaics (PV) over the last few years, only approximately 1.07 billion kWhr of electricity is estimated to have been generated from PV in the US during 2008, or 0.27% of total electrical generation. PV market penetration is set for a paradigm shift, as fluctuating hydrocarbon prices and an acknowledgement of the environmental impacts associated with their use, combined with breakthrough new PV technologies, such as thin-film and BIPV, are driving the cost of energy generated with PV to parity or cost advantage versus more traditional forms of energy generation. In addition to reaching cost parity with grid supplied power, a key to the long-term success of PV as a viable energy alternative is the reliability of systems in the field. New technologies may or may not have the same failure modes as previous technologies. Reliability testing and product lifetime issues continue to be one of the key bottlenecks in the rapid commercialization of PV technologies today. In this paper, we highlight the critical need for moving away from relying on traditional qualification and safety tests as a measure of reliability and focus instead on designing for reliability and its integration into the product development process. A drive towards quantitative predictive accelerated testing is emphasized and an industrial collaboration model addressing reliability challenges is proposed.

  7. SGHWR fuel performance, safety and reliability

    International Nuclear Information System (INIS)

    Pickman, D.O.; Inglis, G.H.

    1977-01-01

    The design principles involved in fuel pins and elements need to take account of the sometimes conflicting requirements of performance, safety and reliability. The principal factors involved in this optimisation are discussed and it is shown from fuel irradiation experience in the Winfrith S.G.H.W.R. that the necessary bias toward safety has not resulted in a reliability level lower than that shown by other successful water reactor designs. Reliability has important economic implications and has to be paid for. By a detailed evaluation of S.G.H.W.R. fuel defects it is shown that very few defects can be shown to be related to design, rating or burn-up. This demonstrates that economic aspects have not over-ridden necessary criteria that must be met to achieve the desirable reliability level. It is possible that large-scale experience with S.G.H.W.R. fuel may eventually demonstrate that the balance is too much in favour of reliability and consideration may be given to whether design changes favouring economy could be achieved without compromising safety. The safety criteria applied to S.G.H.W.R. fuel are designed to avoid any possibility of a temperature runaway in any credible accident situation. The philosophy and supporting experimental work programme are outlined and the fuel design features which particularly contribute to maximising safety margins are outlined. Reference is made to new 60 pin fuel element to be used in the commercial S.G.H.W.R.'s and how it compares in design and performance aspects with the 36 pin element that has been used to date in the Winfrith S.G.H.W.R

  8. Education Vouchers, Growth and Income Inequality

    OpenAIRE

    Buly A Cardak

    2004-01-01

    This paper uses a growth model with public and private education alternatives to investigate the implications of education voucher for economic growth and the evolution of income inequality. The results indicate that introducing education vouchers can increase economic growth. families that switch from public to private education due to vouchers experience higher incomes, leading to growth in the tax base which in turn raises public education expenditures and increases the growth of the whole...

  9. Reliability engineering

    International Nuclear Information System (INIS)

    Lee, Chi Woo; Kim, Sun Jin; Lee, Seung Woo; Jeong, Sang Yeong

    1993-08-01

    This book start what is reliability? such as origin of reliability problems, definition of reliability and reliability and use of reliability. It also deals with probability and calculation of reliability, reliability function and failure rate, probability distribution of reliability, assumption of MTBF, process of probability distribution, down time, maintainability and availability, break down maintenance and preventive maintenance design of reliability, design of reliability for prediction and statistics, reliability test, reliability data and design and management of reliability.

  10. Demonstrating the Safety and Reliability of a New System or Spacecraft: Incorporating Analyses and Reviews of the Design and Processing in Determining the Number of Tests to be Conducted

    Science.gov (United States)

    Vesely, William E.; Colon, Alfredo E.

    2010-01-01

    Design Safety/Reliability is associated with the probability of no failure-causing faults existing in a design. Confidence in the non-existence of failure-causing faults is increased by performing tests with no failure. Reliability-Growth testing requirements are based on initial assurance and fault detection probability. Using binomial tables generally gives too many required tests compared to reliability-growth requirements. Reliability-Growth testing requirements are based on reliability principles and factors and should be used.

  11. A SOFTWARE RELIABILITY ESTIMATION METHOD TO NUCLEAR SAFETY SOFTWARE

    Directory of Open Access Journals (Sweden)

    GEE-YONG PARK

    2014-02-01

    Full Text Available A method for estimating software reliability for nuclear safety software is proposed in this paper. This method is based on the software reliability growth model (SRGM, where the behavior of software failure is assumed to follow a non-homogeneous Poisson process. Two types of modeling schemes based on a particular underlying method are proposed in order to more precisely estimate and predict the number of software defects based on very rare software failure data. The Bayesian statistical inference is employed to estimate the model parameters by incorporating software test cases as a covariate into the model. It was identified that these models are capable of reasonably estimating the remaining number of software defects which directly affects the reactor trip functions. The software reliability might be estimated from these modeling equations, and one approach of obtaining software reliability value is proposed in this paper.

  12. A reliability analysis framework with Monte Carlo simulation for weld structure of crane's beam

    Science.gov (United States)

    Wang, Kefei; Xu, Hongwei; Qu, Fuzheng; Wang, Xin; Shi, Yanjun

    2018-04-01

    The reliability of the crane product in engineering is the core competitiveness of the product. This paper used Monte Carlo method analyzed the reliability of the weld metal structure of the bridge crane whose limit state function is mathematical expression. Then we obtained the minimum reliable welding feet height value for the welds between cover plate and web plate on main beam in different coefficients of variation. This paper provides a new idea and reference for the growth of the inherent reliability of crane.

  13. Corporal Punishment: Legalities, Realities, and Implications.

    Science.gov (United States)

    Hinchey, Patricia H.

    2003-01-01

    Presents a quiz that will help readers determine the reliability of their own perceptions relating to corporal punishment in schools. Discusses U.S. Courts and corporal punishment, worldwide and nationwide legality, and the realities of corporal punishment in the United States. Discusses implications for what teachers can do to address corporal…

  14. Reliability of DSM-IV Symptom Ratings of ADHD: Implications for DSM-V

    Science.gov (United States)

    Solanto, Mary V.; Alvir, Jose

    2009-01-01

    Objective: The objective of this study was to examine the intrarater reliability of "DSM-IV" ADHD symptoms. Method: Two-hundred-two children referred for attention problems and 49 comparison children (all 7-12 years) were rated by parents and teachers on the identical "DSM-IV" items presented in two different formats, the…

  15. Intra- and Interobserver Reliability of Three Classification Systems for Hallux Rigidus.

    Science.gov (United States)

    Dillard, Sarita; Schilero, Christina; Chiang, Sharon; Pham, Peter

    2018-04-18

    There are over ten classification systems currently used in the staging of hallux rigidus. This results in confusion and inconsistency with radiographic interpretation and treatment. The reliability of hallux rigidus classification systems has not yet been tested. The purpose of this study was to evaluate intra- and interobserver reliability using three commonly used classifications for hallux rigidus. Twenty-one plain radiograph sets were presented to ten ACFAS board-certified foot and ankle surgeons. Each physician classified each radiograph based on clinical experience and knowledge according to the Regnauld, Roukis, and Hattrup and Johnson classification systems. The two-way mixed single-measure consistency intraclass correlation was used to calculate intra- and interrater reliability. The intrarater reliability of individual sets for the Roukis and Hattrup and Johnson classification systems was "fair to good" (Roukis, 0.62±0.19; Hattrup and Johnson, 0.62±0.28), whereas the intrarater reliability of individual sets for the Regnauld system bordered between "fair to good" and "poor" (0.43±0.24). The interrater reliability of the mean classification was "excellent" for all three classification systems. Conclusions Reliable and reproducible classification systems are essential for treatment and prognostic implications in hallux rigidus. In our study, Roukis classification system had the best intrarater reliability. Although there are various classification systems for hallux rigidus, our results indicate that all three of these classification systems show reliability and reproducibility.

  16. How reliable are case formulations? A systematic literature review.

    Science.gov (United States)

    Flinn, Lucinda; Braham, Louise; das Nair, Roshan

    2015-09-01

    This systematic literature review investigated the inter-rater and test-retest reliability of case formulations. We considered the reliability of case formulations across a range of theoretical modalities and the general quality of the primary research studies. A systematic search of five electronic databases was conducted in addition to reference list trawling to find studies that assessed the reliability of case formulation. This yielded 18 studies for review. A methodological quality assessment tool was developed to assess the quality of studies, which informed interpretation of the findings. Results indicated inter-rater reliability mainly ranging from slight (.1-.4) to substantial (.81-1.0). Some studies highlighted that training and increased experience led to higher levels of agreement. In general, psychodynamic formulations appeared to generate somewhat increased levels of reliability than cognitive or behavioural formulations; however, these studies also included methods that may have served to inflate reliability, for example, pooling the scores of judges. Only one study investigated the test-retest reliability of case formulations yielding support for the stability of formulations over a 3-month period. Reliability of case formulations is varied across a range of theoretical modalities, but can be improved; however, further research is required to strengthen our conclusions. Clinical implications: The findings from the review evidence some support for case formulation being congruent with the scientist-practitioner approach. The reliability of case formulation is likely to be improved through training and clinical experience. Limitations: The broad inclusion criteria may have introduced heterogeneity into the sample, which may have affected the results. Studies reviewed were limited to peer-reviewed journal articles written in the English language, which may represent a source of publication and selection bias. © 2014 The British Psychological Society.

  17. Reliability prediction of engineering systems with competing failure modes due to component degradation

    International Nuclear Information System (INIS)

    Son, Young Kap

    2011-01-01

    Reliability of an engineering system depends on two reliability metrics: the mechanical reliability, considering component failures, that a functional system topology is maintained and the performance reliability of adequate system performance in each functional configuration. Component degradation explains not only the component aging processes leading to failure in function, but also system performance change over time. Multiple competing failure modes for systems with degrading components in terms of system functionality and system performance are considered in this paper with the assumption that system functionality is not independent of system performance. To reduce errors in system reliability prediction, this paper tries to extend system performance reliability prediction methods in open literature through combining system mechanical reliability from component reliabilities and system performance reliability. The extended reliability prediction method provides a useful way to compare designs as well as to determine effective maintenance policy for efficient reliability growth. Application of the method to an electro-mechanical system, as an illustrative example, is explained in detail, and the prediction results are discussed. Both mechanical reliability and performance reliability are compared to total system reliability in terms of reliability prediction errors

  18. Systems reliability/structural reliability

    International Nuclear Information System (INIS)

    Green, A.E.

    1980-01-01

    The question of reliability technology using quantified techniques is considered for systems and structures. Systems reliability analysis has progressed to a viable and proven methodology whereas this has yet to be fully achieved for large scale structures. Structural loading variants over the half-time of the plant are considered to be more difficult to analyse than for systems, even though a relatively crude model may be a necessary starting point. Various reliability characteristics and environmental conditions are considered which enter this problem. The rare event situation is briefly mentioned together with aspects of proof testing and normal and upset loading conditions. (orig.)

  19. Reliability of risk assessment measures used in sexually violent predator proceedings.

    Science.gov (United States)

    Miller, Cailey S; Kimonis, Eva R; Otto, Randy K; Kline, Suzonne M; Wasserman, Adam L

    2012-12-01

    The field interrater reliability of three assessment tools frequently used by mental health professionals when evaluating sex offenders' risk for reoffending--the Psychopathy Checklist-Revised (PCL-R), the Minnesota Sex Offender Screening Tool-Revised (MnSOST-R) and the Static-99-was examined within the context of sexually violent predator program proceedings. Rater agreement was highest for the Static--99 (intraclass correlation coefficient [ICC₁] = .78) and lowest for the PCL-R (ICC₁ = .60; MnSOST-R ICC₁ = .74), although all instruments demonstrated lower field reliability than that reported in their test manuals. Findings raise concerns about the reliability of risk assessment tools that are used to inform judgments of risk in high-stake sexually violent predator proceedings. Implications for future research and suggestions for improving evaluator training to increase accuracy when informing legal decision making are discussed.

  20. Reliability Engineering

    International Nuclear Information System (INIS)

    Lee, Sang Yong

    1992-07-01

    This book is about reliability engineering, which describes definition and importance of reliability, development of reliability engineering, failure rate and failure probability density function about types of it, CFR and index distribution, IFR and normal distribution and Weibull distribution, maintainability and movability, reliability test and reliability assumption in index distribution type, normal distribution type and Weibull distribution type, reliability sampling test, reliability of system, design of reliability and functionality failure analysis by FTA.

  1. Plant lifetime reliability and risk: Addressing today's strategies for making tomorrow's decisions

    International Nuclear Information System (INIS)

    Boccio, J.L.

    1986-01-01

    This paper presents an overview of some of the research projects, conducted for the US Nuclear Regulatory Commission (NRC) that deal with the question: How can an acceptable level of risk of a nuclear power plant be maintained throughout its design life? With a viewpoint that life extension planning for a plant can be viewed as a long-range, strategic maintenance program, the products of this research are discussed from the perspective of being elements that can tie day-to-day, plant operational tactical decisions on component/system reliability with long-range strategic maintenance goals. A common factor in addressing issues associated with design life and life extension is the issue of component aging and the reliability implications of aging. A time-dependent reliability model is described which contains some of the requisite ingredients and is built on a framework from which the component aging/component reliability issue can be addressed. By way of select examples, the additional work needed to further address plant lifetime reliability and risk is indicated

  2. Employment and Growth | Page 28 | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Employment and Growth. Language English. Read more about Development Implications of Liberalization of Trade in Services. Language English. Read more about Micro Level Perspectives on Growth (Tanzania). Language English. Read more about Southern African Development Research Network. Language English.

  3. Reliability of structures by using probability and fatigue theories

    International Nuclear Information System (INIS)

    Lee, Ouk Sub; Kim, Dong Hyeok; Park, Yeon Chang

    2008-01-01

    Methodologies to calculate failure probability and to estimate the reliability of fatigue loaded structures are developed. The applicability of the methodologies is evaluated with the help of the fatigue crack growth models suggested by Paris and Walker. The probability theories such as the FORM (first order reliability method), the SORM (second order reliability method) and the MCS (Monte Carlo simulation) are utilized. It is found that the failure probability decreases with the increase of the design fatigue life and the applied minimum stress, the decrease of the initial edge crack size, the applied maximum stress and the slope of Paris equation. Furthermore, according to the sensitivity analysis of random variables, the slope of Pairs equation affects the failure probability dominantly among other random variables in the Paris and the Walker models

  4. Economic growth and inflation rate: implications for municipal revenue and health expenditure of the municipalities of Pernambuco, Brazil.

    Science.gov (United States)

    Feliciano, Marciana; Bezerra, Adriana Falangola Benjamin; Santo, Antônio Carlos Gomes do Espírito

    2017-06-01

    This paper analyzes the implications of municipal budget revenue growth and the monetary policy's inflation rates goals in the availability of public health resources of municipalities. This is a descriptive, exploratory, quantitative, retrospective and longitudinal cross-sectional study covering the period 2002-2011. We analyzed health financing and expenditure variables in the municipalities of the state of Pernambuco, Brazil, describing the trend and the relationship between them. Data showed the growth of the variables and trend towards homogeneity. The exception was for the participation of Intergovernmental Transfers in the Total Health Expenditure of the Municipality. We found a significant correlation between Budget Revenue per capita and Health Expenditure per capita and a strong significant negative correlation between Inflation Rate, Budget Revenue per capita and Health Expenditure per capita. We concluded that increased health expenditure is due more to higher municipal tax revenue than to increased transfers that, in relative terms, did not increase. The strong inverse relationship between inflation rate and the Financing and Expenditure variables show that the monetary policy's inflation goals have restricted health financing to municipalities.

  5. Analysis of domestic debt: implication for economic growth in Nigeria

    African Journals Online (AJOL)

    This paper principally analysed the importance of domestic debt on economic growth of Nigeria. The objective of the study is to investigate the relationship between government domestic debt and economic growth and policy that is likely to improve private sector investment and break growth resistance problem.

  6. Reliability

    OpenAIRE

    Condon, David; Revelle, William

    2017-01-01

    Separating the signal in a test from the irrelevant noise is a challenge for all measurement. Low test reliability limits test validity, attenuates important relationships, and can lead to regression artifacts. Multiple approaches to the assessment and improvement of reliability are discussed. The advantages and disadvantages of several different approaches to reliability are considered. Practical advice on how to assess reliability using open source software is provided.

  7. Employment and Growth | Page 49 | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Employment and Growth. Emploi et croissance. Language English. Read more about Development Implications of Liberalization of Trade in Services. Language English. Read more about Micro Level Perspectives on Growth (Tanzania). Language English. Read more about Southern African Development Research ...

  8. Test-retest reliability and practice effects of the Wechsler Memory Scale-III.

    Science.gov (United States)

    Lo, Ada H Y; Humphreys, Michael; Byrne, Gerard J; Pachana, Nancy A

    2012-09-01

    Although serial administration of cognitive tests is increasingly common, there is a paucity of research on test-retest reliabilities and practice effects, both of which are important for evaluating changes in functioning. Reliability is generally conceptualized as involving short-lasting changes in performance. However, when repeated testing occurs over a period of years, there will be some longer lasting effects. The implications of these longer lasting effects and practice effects on reliability were examined in the context of repeated administrations of the Wechsler Memory Scale-III in 339 community-dwelling women aged 40-79 years over 2 to 7 years. The results showed that Logical Memory and Verbal Paired Associates subtests were consistently the most reliable subtests across the age cohorts. The magnitude of practice effects varied as a function of subtests and age. The largest practice effects were found in the youngest age cohort, especially on the Faces, Logical Memory, and Verbal Paired Associates subtests. ©2012 The British Psychological Society.

  9. The economic growth enigma: Capital, labour and useful energy?

    International Nuclear Information System (INIS)

    Ayres, Robert; Voudouris, Vlasios

    2014-01-01

    We show that the application of flexible semi-parametric statistical techniques enables significant improvements in model fitting of macroeconomic models. As applied to the explanation of the past economic growth (since 1900) in US, UK and Japan, the new results demonstrate quite conclusively the non-linear relationships between capital, labour and useful energy with economic growth. They also indicate that output elasticities of capital, labour and useful energy are extremely variable over time. We suggest that these results confirm the economic intuition that growth since the industrial revolution has been driven largely by declining energy costs due to the discovery and exploitation of relatively inexpensive fossil fuel resources. Implications for the 21st century, which are also discussed briefly by exploring the implications of an ACEGES-based scenario of oil production, are as follows: (a) the provision of adequate and affordable quantities of useful energy as a pre-condition for economic growth and (b) the design of energy systems as ‘technology incubators’ for a prosperous 21st century. - Highlights: • Economic growth needs three factors of production. • We propose a semi-parametric generalised production function. • Exploitation of inexpensive fossil fuel resources has profound policy implications

  10. Bacterial growth kinetics

    International Nuclear Information System (INIS)

    Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.

    1989-01-01

    Quantitative measurement of bacterial growth may be made using a radioassay technique. This method measures, by scintillation counting, the 14 CO 2 derived from the bacterial metabolism of a 14 C-labeled substrate. Mathematical growth models may serve as reliable tools for estimation of the generation rate constant (or slope of the growth curve) and provide a basis for evaluating assay performance. Two models, i.e., exponential and logistic, are proposed. Both models yielded an accurate fit to the data from radioactive measurement of bacterial growth. The exponential model yielded high precision values of the generation rate constant, with an average relative standard deviation of 1.2%. Under most conditions the assay demonstrated no changes in the slopes of growth curves when the number of bacteria per inoculation was changed. However, the radiometric assay by scintillation method had a growth-inhibiting effect on a few strains of bacteria. The source of this problem was thought to be hypersensitivity to trace amounts of toluene remaining on the detector

  11. Aid and Growth

    DEFF Research Database (Denmark)

    Arndt, Channing; Jones, Edward Samuel; Tarp, Finn

    , are being drawn on the basis of fragile evidence. This paper first assesses the aid-growth literature with a focus on recent contributions. The aid-growth literature is then framed, for the first time, in terms of the Rubin Causal Model, applied at the macroeconomic level. Our results show that aid has......The micro-macro paradox has been revived. Despite broadly positive evaluations at the micro and meso-levels, recent literature has turned decidedly pessimistic with respect to the ability of foreign aid to foster economic growth. Policy implications, such as the complete cessation of aid to Africa...... a positive and statistically significant causal effect on growth over the long run with point estimates at levels suggested by growth theory. We conclude that aid remains an important tool for enhancing the development prospects of poor nations....

  12. Reliability-based assessment of deteriorating ship structures operating in multiple sea loading climates

    Energy Technology Data Exchange (ETDEWEB)

    Moan, Torgeir [Centre for Ships and Ocean Structures, Norwegian University of Science and Technology, Marine Technology Centre, Tyholt, N 7491 Trondheim (Norway)], E-mail: tormo@marin.ntnu.no; Ayala-Uraga, Efren [Department of Marine Technology, Norwegian University of Science and Technology, Marine Technology Centre, Tyholt, N 7491 Trondheim (Norway)

    2008-03-15

    A reliability-based model for assessment of deteriorating ships subjected to multiple environmental conditions is established. Deterioration due to combined crack growth and corrosion in structural components of a ship hull is accounted for based on a fracture mechanics formulation. The model enables to take into account the corrosion-induced increased crack growth rate in two ways: (1) the increased stress range produced by the plate thinning (wastage) effect and (2) corrosion fatigue itself. Sensitivity studies are carried out to evaluate the effect of inspection updating on a production ship subjected to two different climate conditions. The hazard rate concept is adopted as a measure of reliability and emphasized throughout the different case studies.

  13. Extreme storms, sea level rise, and coastal change: implications for infrastructure reliability in the Gulf of Mexico

    Science.gov (United States)

    Anarde, K.; Kameshwar, S.; Irza, N.; Lorenzo-Trueba, J.; Nittrouer, J. A.; Padgett, J.; Bedient, P. B.

    2016-12-01

    Predicting coastal infrastructure reliability during hurricane events is important for risk-based design and disaster planning, such as delineating viable emergency response routes. Previous research has focused on either infrastructure vulnerability to coastal flooding or the impact of changing sea level and landforms on surge dynamics. Here we investigate the combined impact of sea level, morphology, and coastal flooding on the reliability of highway bridges - the only access points between barrier islands and mainland communities - during future extreme storms. We forward model coastal flooding for static projections of geomorphic change using ADCIRC+SWAN. First-order parameters that are adjusted include sea level and elevation. These are varied for each storm simulation to evaluate relative impact on the reliability of bridges surrounding Freeport, TX. Simulated storms include both synthetic and historical events, which are classified by intensity using the storm's integrated kinetic energy, a metric for surge generation potential. Reliability is estimated through probability of failure - given wave and surge loads - and time inundated. Findings include that: 1) bridge reliability scales inversely with surge height, and 2) sea level rise reduces bridge reliability due to a monotonic increase in surge height. The impact of a shifting landscape on bridge reliability is more complex: barrier island rollback can increase or decrease inundation times for storms of different intensity due to changes in wind-setup and back-barrier bay interactions. Initial storm surge readily inundates the coastal landscape during large intensity storms, however the draining of inland bays following storm passage is significantly impeded by the barrier. From a coastal engineering standpoint, we determine that to protect critical infrastructure, efforts now implemented that nourish low-lying barriers may be enhanced by also armoring back-bay coastlines and elevating bridge approach

  14. Emittance growth due to negative-mass instability above transition

    International Nuclear Information System (INIS)

    Ng, King-Yuen.

    1994-08-01

    Due to space-charge effect, there is a growth of bunch emittance across transition as a result of negative-mass instability. The models of growth at cutoff frequency and growth from high-frequency Schottky noise are reviewed. The difficulties of performing reliable simulations are discussed. An intuitive self-bunching model for estimating emittance growth is presented

  15. Translation, reliability, and clinical utility of the Melbourne Assessment 2.

    Science.gov (United States)

    Gerber, Corinna N; Plebani, Anael; Labruyère, Rob

    2017-10-12

    The aims were to (i) provide a German translation of the Melbourne Assessment 2 (MA2), a quantitative test to measure unilateral upper limb function in children with neurological disabilities and (ii) to evaluate its reliability and aspects of clinical utility. After its translation into German and approval of the back translation by the original authors, the MA2 was performed and videotaped twice with 30 children with neuromotor disorders. For each participant, two raters scored the video of the first test for inter-rater reliability. To determine test-retest reliability, one rater additionally scored the video of the second test while the other rater repeated the scoring of the first video to evaluate intra-rater reliability. Time needed for rater training, test administration, and scoring was recorded. The four subscale scores showed excellent intra-, inter-rater, and test-retest reliability with intraclass correlation coefficients of 0.90-1.00 (95%-confidence intervals 0.78-1.00). Score items revealed substantial to almost perfect intra-rater reliability (weighted kappa k w  = 0.66-1.00) for the more affected side. Score item inter-rater and test-retest reliability of the same extremity were, with one exception, moderate to almost perfect (k w  = 0.42-0.97; k w  = 0.40-0.89). Furthermore, the MA2 was feasible and acceptable for patients and clinicians. The MA2 showed excellent subscale and moderate to almost perfect score item reliability. Implications for Rehabilitation There is a lack of high-quality studies about psychometric properties of upper limb measurement tools in the neuropediatric population. The Melbourne Assessment 2 is a promising tool for reliable measurement of unilateral upper limb movement quality in the neuropediatric population. The Melbourne Assessment 2 is acceptable and practicable to therapists and patients for routine use in clinical care.

  16. Theory and practice of quality and reliability engineering in Asia industry

    CERN Document Server

    Goh, Thong

    2017-01-01

    This book discusses the application of quality and reliability engineering in Asian industries, and offers information for multinational companies (MNC) looking to transfer some of their operation and manufacturing capabilities to Asia and at the same time maintain high levels of reliability and quality. It is also provides small and medium enterprises (SME) in Asia with insights into producing high-quality and reliable products. It mainly comprises peer-reviewed papers that were presented at the Asian Network for Quality (ANQ) Congress 2014 held in Singapore (August, 2014), which provides a platform for companies, especially those within Asia where rapid changes and growth in manufacturing are taking place, to present their quality and reliability practices. The book presents practical demonstrations of how quality and reliability methodologies can be modified for the unique Asian market, and as such is a valuable resource for students, academics, professionals and practitioners in the field of quality and r...

  17. Heroic Reliability Improvement in Manned Space Systems

    Science.gov (United States)

    Jones, Harry W.

    2017-01-01

    System reliability can be significantly improved by a strong continued effort to identify and remove all the causes of actual failures. Newly designed systems often have unexpected high failure rates which can be reduced by successive design improvements until the final operational system has an acceptable failure rate. There are many causes of failures and many ways to remove them. New systems may have poor specifications, design errors, or mistaken operations concepts. Correcting unexpected problems as they occur can produce large early gains in reliability. Improved technology in materials, components, and design approaches can increase reliability. The reliability growth is achieved by repeatedly operating the system until it fails, identifying the failure cause, and fixing the problem. The failure rate reduction that can be obtained depends on the number and the failure rates of the correctable failures. Under the strong assumption that the failure causes can be removed, the decline in overall failure rate can be predicted. If a failure occurs at the rate of lambda per unit time, the expected time before the failure occurs and can be corrected is 1/lambda, the Mean Time Before Failure (MTBF). Finding and fixing a less frequent failure with the rate of lambda/2 per unit time requires twice as long, time of 1/(2 lambda). Cutting the failure rate in half requires doubling the test and redesign time and finding and eliminating the failure causes.Reducing the failure rate significantly requires a heroic reliability improvement effort.

  18. Assessment of torque-steadiness reliability at the ankle level in healthy young subjects: implications for cerebral palsy

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Rose, Martin Høyer; Sonne-Holm, Stig

    2008-01-01

    It was the primary objective of this study to investigate whether quantifying fluctuations in dorsi and plantarflexor torque during submaximal isometric contractions is a reliable measurement in young healthy subjects. A secondary objective was to investigate the reliability of the associated mus...

  19. Novel Actions of Growth Hormone in Podocytes: Implications for Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Dhanunjay Mukhi

    2017-07-01

    Full Text Available The kidney regulates water, electrolyte, and acid-base balance and thus maintains body homeostasis. The kidney’s potential to ensure ultrafiltered and almost protein-free urine is compromised in various metabolic and hormonal disorders such as diabetes mellitus (DM. Diabetic nephropathy (DN accounts for ~20–40% of mortality in DM. Proteinuria, a hallmark of renal glomerular diseases, indicates injury to the glomerular filtration barrier (GFB. The GFB is composed of glomerular endothelium, basement membrane, and podocytes. Podocytes are terminally differentiated epithelial cells with limited ability to replicate. Podocyte shape and number are both critical for the integrity and function of the GFB. Podocytes are vulnerable to various noxious stimuli prevalent in a diabetic milieu that could provoke podocytes to undergo changes to their unique architecture and function. Effacement of podocyte foot process is a typical morphological alteration associated with proteinuria. The dedifferentiation of podocytes from epithelial-to-mesenchymal phenotype and consequential loss results in proteinuria. Poorly controlled type 1 DM is associated with elevated levels of circulating growth hormone (GH, which is implicated in the pathophysiology of various diabetic complications including DN. Recent studies demonstrate that functional GH receptors are expressed in podocytes and that GH may exert detrimental effects on the podocyte. In this review, we summarize recent advances that shed light on actions of GH on the podocyte that could play a role in the pathogenesis of DN.

  20. Measuring theory of mind across middle childhood: Reliability and validity of the Silent Films and Strange Stories tasks.

    Science.gov (United States)

    Devine, Rory T; Hughes, Claire

    2016-09-01

    Recent years have seen a growth of research on the development of children's ability to reason about others' mental states (or "theory of mind") beyond the narrow confines of the preschool period. The overall aim of this study was to investigate the psychometric properties of a task battery composed of items from Happé's Strange Stories task and Devine and Hughes' Silent Film task. A sample of 460 ethnically and socially diverse children (211 boys) between 7 and 13years of age completed the task battery at two time points separated by 1month. The Strange Stories and Silent Film tasks were strongly correlated even when verbal ability and narrative comprehension were taken into account, and all items loaded onto a single theory-of-mind latent factor. The theory-of-mind latent factor provided reliable estimates of performance across a wide range of theory-of-mind ability and showed no evidence of differential item functioning across gender, ethnicity, or socioeconomic status. The theory-of-mind latent factor also exhibited strong 1-month test-retest reliability, and this stability did not vary as a function of child characteristics. Taken together, these findings provide evidence for the validity and reliability of the Strange Stories and Silent Film task battery as a measure of individual differences in theory of mind suitable for use across middle childhood. We consider the methodological and conceptual implications of these findings for research on theory of mind beyond the preschool years. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Damage tolerance reliability analysis of automotive spot-welded joints

    International Nuclear Information System (INIS)

    Mahadevan, Sankaran; Ni Kan

    2003-01-01

    This paper develops a damage tolerance reliability analysis methodology for automotive spot-welded joints under multi-axial and variable amplitude loading history. The total fatigue life of a spot weld is divided into two parts, crack initiation and crack propagation. The multi-axial loading history is obtained from transient response finite element analysis of a vehicle model. A three-dimensional finite element model of a simplified joint with four spot welds is developed for static stress/strain analysis. A probabilistic Miner's rule is combined with a randomized strain-life curve family and the stress/strain analysis result to develop a strain-based probabilistic fatigue crack initiation life prediction for spot welds. Afterwards, the fatigue crack inside the base material sheet is modeled as a surface crack. Then a probabilistic crack growth model is combined with the stress analysis result to develop a probabilistic fatigue crack growth life prediction for spot welds. Both methods are implemented with MSC/NASTRAN and MSC/FATIGUE software, and are useful for reliability assessment of automotive spot-welded joints against fatigue and fracture

  2. Selective LPCVD growth of graphene on patterned copper and its growth mechanism

    Science.gov (United States)

    Zhang, M.; Huang, B.-C.; Wang, Y.; Woo, J. C. S.

    2016-12-01

    Copper-catalyzed graphene low-pressure chemical-vapor deposition (LPCVD) growth has been regarded as a viable solution towards its integration to CMOS technology, and the wafer-bonding method provides a reliable alternative for transferring the selective graphene grown on a patterned metal film for IC manufacturing. In this paper, selective LPCVD graphene growth using patterned copper dots has been studied. The Raman spectra of grown films have demonstrated large dependence on the growth conditions. To explain the results, the growth mechanisms based on surface adsorption and copper-vapor-assisted growth are investigated by the comparison between the blanket copper films with/without the additional copper source. The copper vapor density is found to be critical for high-quality graphene growth. In addition, the copper-vapor-assisted growth is also evidenced by the carbon deposition on the SiO2 substrate of the patterned-copper-dot sample and chamber wall during graphene growth. This growth mechanism explains the correlation between the growth condition and Raman spectrum for films on copper dots. The study on the copper-catalyzed selective graphene growth on the hard substrate paves the way for the synthesis and integration of the 2D material in VLSI.

  3. High-reliability computing for the smarter planet

    International Nuclear Information System (INIS)

    Quinn, Heather M.; Graham, Paul; Manuzzato, Andrea; Dehon, Andre

    2010-01-01

    The geometric rate of improvement of transistor size and integrated circuit performance, known as Moore's Law, has been an engine of growth for our economy, enabling new products and services, creating new value and wealth, increasing safety, and removing menial tasks from our daily lives. Affordable, highly integrated components have enabled both life-saving technologies and rich entertainment applications. Anti-lock brakes, insulin monitors, and GPS-enabled emergency response systems save lives. Cell phones, internet appliances, virtual worlds, realistic video games, and mp3 players enrich our lives and connect us together. Over the past 40 years of silicon scaling, the increasing capabilities of inexpensive computation have transformed our society through automation and ubiquitous communications. In this paper, we will present the concept of the smarter planet, how reliability failures affect current systems, and methods that can be used to increase the reliable adoption of new automation in the future. We will illustrate these issues using a number of different electronic devices in a couple of different scenarios. Recently IBM has been presenting the idea of a 'smarter planet.' In smarter planet documents, IBM discusses increased computer automation of roadways, banking, healthcare, and infrastructure, as automation could create more efficient systems. A necessary component of the smarter planet concept is to ensure that these new systems have very high reliability. Even extremely rare reliability problems can easily escalate to problematic scenarios when implemented at very large scales. For life-critical systems, such as automobiles, infrastructure, medical implantables, and avionic systems, unmitigated failures could be dangerous. As more automation moves into these types of critical systems, reliability failures will need to be managed. As computer automation continues to increase in our society, the need for greater radiation reliability is necessary

  4. High-reliability computing for the smarter planet

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Heather M [Los Alamos National Laboratory; Graham, Paul [Los Alamos National Laboratory; Manuzzato, Andrea [UNIV OF PADOVA; Dehon, Andre [UNIV OF PENN; Carter, Nicholas [INTEL CORPORATION

    2010-01-01

    The geometric rate of improvement of transistor size and integrated circuit performance, known as Moore's Law, has been an engine of growth for our economy, enabling new products and services, creating new value and wealth, increasing safety, and removing menial tasks from our daily lives. Affordable, highly integrated components have enabled both life-saving technologies and rich entertainment applications. Anti-lock brakes, insulin monitors, and GPS-enabled emergency response systems save lives. Cell phones, internet appliances, virtual worlds, realistic video games, and mp3 players enrich our lives and connect us together. Over the past 40 years of silicon scaling, the increasing capabilities of inexpensive computation have transformed our society through automation and ubiquitous communications. In this paper, we will present the concept of the smarter planet, how reliability failures affect current systems, and methods that can be used to increase the reliable adoption of new automation in the future. We will illustrate these issues using a number of different electronic devices in a couple of different scenarios. Recently IBM has been presenting the idea of a 'smarter planet.' In smarter planet documents, IBM discusses increased computer automation of roadways, banking, healthcare, and infrastructure, as automation could create more efficient systems. A necessary component of the smarter planet concept is to ensure that these new systems have very high reliability. Even extremely rare reliability problems can easily escalate to problematic scenarios when implemented at very large scales. For life-critical systems, such as automobiles, infrastructure, medical implantables, and avionic systems, unmitigated failures could be dangerous. As more automation moves into these types of critical systems, reliability failures will need to be managed. As computer automation continues to increase in our society, the need for greater radiation reliability is

  5. ANALYSIS OF POWER SYSTEM RELIABILITY IMPROVEMENT FOR 74-BUS RADIAL DISTRIBUTION SYSTEM

    OpenAIRE

    Su Mon Myint*

    2018-01-01

    In Myanmar, electric power system planning is widely constructed because of more and more load growth and facing with failure of electricity, outage problems and system shut-down. Thus, not only making new power system network but also improving reliability of the existing system using suitable methods is very important to provide an adequate supply of electrical energy to its customers as economically and reliably as possible with an acceptable degree of continuity and quality that is design...

  6. Evaluation of tecnological reliability of wind turbine facility Gibara 2

    International Nuclear Information System (INIS)

    Torres Valle, Antonio; Martínez Martín, Erich

    2016-01-01

    Renewable energy, particularly wind, will occupy an important place in the coming decades, marked by the depletion of fossil fuel sources. In Cuba significant growth in the use of these energy sourcesis forecasted. For this reason is importantthe creation of reliable technology to ensure that future mission. The paper proposes as its central objective, the analysis of reliability of Wind Farm Gibara 2 starting from its representation based on the methodology of fault tree and to recommend some possible applications of the results. An essential step in the research is the determination of participating components in the fault tree and processing of the available reliability database at the Wind Farm Gibara 2. The document essentially helpsin the identification of the main contributors to the unavailability of facilities and optimizing maintenance policy. (author)

  7. Age and growth of Sandelia bainsii Castelnau (Pisces: Anabantidae ...

    African Journals Online (AJOL)

    Otoliths and scales were used for age and growth determination of Sandelia bainsii. There was a linear relationship between fish length and both scale and otolith radii. Growth rings were deposited annually in spring. Otoliths provide a more reliable estimate of age and growth than scales. Males grow faster, reach a larger ...

  8. Will British weather provide reliable electricity?

    International Nuclear Information System (INIS)

    Oswald, James; Raine, Mike; Ashraf-Ball, Hezlin

    2008-01-01

    There has been much academic debate on the ability of wind to provide a reliable electricity supply. The model presented here calculates the hourly power delivery of 25 GW of wind turbines distributed across Britain's grid, and assesses power delivery volatility and the implications for individual generators on the system. Met Office hourly wind speed data are used to determine power output and are calibrated using Ofgem's published wind output records. There are two main results. First, the model suggests that power swings of 70% within 12 h are to be expected in winter, and will require individual generators to go on or off line frequently, thereby reducing the utilisation and reliability of large centralised plants. These reductions will lead to increases in the cost of electricity and reductions in potential carbon savings. Secondly, it is shown that electricity demand in Britain can reach its annual peak with a simultaneous demise of wind power in Britain and neighbouring countries to very low levels. This significantly undermines the case for connecting the UK transmission grid to neighbouring grids. Recommendations are made for improving 'cost of wind' calculations. The authors are grateful for the sponsorship provided by The Renewable Energy Foundation

  9. Racial/ethnic variation in the reliability of DSM-IV pathological gambling disorder.

    Science.gov (United States)

    Cunningham-Williams, Renee M; Ostmann, Emily L; Spitznagel, Edward L; Books, Samantha J

    2007-07-01

    Racial/ethnic disparities in mental disorders, including pathological gambling disorder (PGD), may be either real or artifacts of how they are conceptualized and measured. We aimed to assess racial/ethnic variation in the reliability of self-reported lifetime PGD determined by meeting > or = 5 criteria of the Diagnostic and Statistical Manual of Mental Disorders. Using community advertising, we recruited 15-85-year-old Caucasians (n = 225) and African (American/other minorities (n = 87), who had gambled more than 5 times lifetime), for 2 interviews, held 1 week apart, about gambling and associated behaviors. Results indicate substantial to almost-perfect DSM-IV PGD reliability for Caucasians (kappa = 0.82) and African Americans/other minorities (kappa = 0.68). Reliability for symptoms and for game-specific disorders was fair to almost perfect (kappa = 0.37-0.90). After adjusting results for confounding variables and multiple comparisons, racial/ethnic variation in PGD and game-specific reliability failed to persist. Implications exist for increased attention to screening and prevention efforts critical to reducing racial/ethnic disparities in PGD prevalence.

  10. Multinomial-exponential reliability function: a software reliability model

    International Nuclear Information System (INIS)

    Saiz de Bustamante, Amalio; Saiz de Bustamante, Barbara

    2003-01-01

    The multinomial-exponential reliability function (MERF) was developed during a detailed study of the software failure/correction processes. Later on MERF was approximated by a much simpler exponential reliability function (EARF), which keeps most of MERF mathematical properties, so the two functions together makes up a single reliability model. The reliability model MERF/EARF considers the software failure process as a non-homogeneous Poisson process (NHPP), and the repair (correction) process, a multinomial distribution. The model supposes that both processes are statistically independent. The paper discusses the model's theoretical basis, its mathematical properties and its application to software reliability. Nevertheless it is foreseen model applications to inspection and maintenance of physical systems. The paper includes a complete numerical example of the model application to a software reliability analysis

  11. The reliability paradox of the Parent-Child Conflict Tactics Corporal Punishment Subscale.

    Science.gov (United States)

    Lorber, Michael F; Slep, Amy M Smith

    2018-02-01

    In the present investigation we consider and explain an apparent paradox in the measurement of corporal punishment with the Parent-Child Conflict Tactics Scale (CTS-PC): How can it have poor internal consistency and still be reliable? The CTS-PC was administered to a community sample of 453 opposite sex couples who were parents of 3- to 7-year-old children. Internal consistency was marginal, yet item response theory analyses revealed that reliability rose sharply with increasing corporal punishment, exceeding .80 in the upper ranges of the construct. The results suggest that the CTS-PC Corporal Punishment subscale reliably discriminates among parents who report average to high corporal punishment (64% of mothers and 56% of fathers in the present sample), despite low overall internal consistency. These results have straightforward implications for the use and reporting of the scale. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  12. Drug Testing in the Schools. Implications for Policy.

    Science.gov (United States)

    Bozeman, William C.; And Others

    Drug testing of district employees and students is examined from several perspectives: implications for school policy, legality, administration and protocol, and test reliability and accuracy. Substance abuse has become a major concern for educators, parents, and citizens as illegal drugs are more readily available. It is also pointed out that the…

  13. reliability reliability

    African Journals Online (AJOL)

    eobe

    Corresponding author, Tel: +234-703. RELIABILITY .... V , , given by the code of practice. However, checks must .... an optimization procedure over the failure domain F corresponding .... of Concrete Members based on Utility Theory,. Technical ...

  14. Grain growth kinetics of ringwoodite and majorite garnet mixtures and implications for the rheology of the transition zone

    Science.gov (United States)

    Ezad, I.; Dobson, D. P.; Brodholt, J. P.; Thomson, A.; Hunt, S.

    2017-12-01

    The grain size of the transition zone is a poorly known but important geophysical parameter. Among others, the grain size may control the rheology, seismic attenuation and radiative thermal conductivity of the mantle. However, the grain size of the transition zone minerals ringwoodite (Mg,Fe)2SiO4 and majorite garnet MgSiO3 under appropriate zone conditions is currently unknown and there are very few experiments with which to constrain it. In order to determine the grain size of the transition zone, the grain growth kinetics must be determined for a range of mantle compositions. We have, therefore, experimentally determined the grain growth kinetics of the lowermost transition zone minerals through multi anvil experiments at University College London (UCL). This is achieved through a comprehensive set of time series experiments at pressures of 21 GPa and temperatures relevant to the transition zone. We have also determined the effect of varying water content, oxygen fugacity, iron content and aluminium content also discussed by Dobson and Mariani., (2014). Our initial grain growth experiments conducted at 1200°C and 1400°C at 18 GPa show extremely slow grain growth kinetics; time series experiments extended to 105.8 seconds are unable to produce grains larger than 100 nm. This suggests that fine-grained material at the base of the transition zone will persist on geological timescales. Such small grains size suggests that diffusion creep might be the dominant deformation mechanism in this region. Reference: Dobson, D.P., Mariani, E., 2014. The kinetics of the reaction of majorite plus ferropericlase to ringwoodite: Implications for mantle upwellings crossing the 660 km discontinuity. Earth Planet. Sci. Lett. 408, 110-118. doi:10.1016/j.epsl.2014.10.009

  15. Evidence of Reliability and Validity for a Children’s Auditory Continuous Performance Test

    Directory of Open Access Journals (Sweden)

    Michael J. Lasee

    2013-11-01

    Full Text Available Continuous Performance Tests (CPTs are commonly utilized clinical measures of attention and response inhibition. While there have been many studies of CPTs that utilize a visual format, there is considerably less research employing auditory CPTs. The current study provides initial reliability and validity evidence for the Auditory Vigilance Screening Measure (AVSM, a newly developed CPT. Participants included 105 five- to nine-year-old children selected from two rural Midwestern school districts. Reliability data for the AVSM was collected through retesting of 42 participants. Validity was evaluated through correlation of AVSM scales with subscales from the ADHD Rating Scale–IV. Test–retest reliability coefficients ranged from .62 to .74 for AVSM subscales. A significant (r = .31 correlation was obtained between the AVSM Impulsivity Scale and teacher ratings of inattention. Limitations and implications for future study are discussed.

  16. Deconstructing the BRICs : Structural transformation and aggregate productivity growth

    NARCIS (Netherlands)

    de Vries, G.J.; Erumban, Abdul Azeez; Timmer, M.P.; Voskoboynikov, I.; Wu, H.X.

    de Vries, Gaaitzen J., Erumban, Abdul A., Timmer, Marcel P., Voskoboynikov, Ilya-Deconstructing the BRICs: Structural transformation and aggregate productivity growth This paper studies structural transformation and its implications for productivity growth in the BRIC countries (Brazil, Russia,

  17. Measuring reliability under epistemic uncertainty: Review on non-probabilistic reliability metrics

    Directory of Open Access Journals (Sweden)

    Kang Rui

    2016-06-01

    Full Text Available In this paper, a systematic review of non-probabilistic reliability metrics is conducted to assist the selection of appropriate reliability metrics to model the influence of epistemic uncertainty. Five frequently used non-probabilistic reliability metrics are critically reviewed, i.e., evidence-theory-based reliability metrics, interval-analysis-based reliability metrics, fuzzy-interval-analysis-based reliability metrics, possibility-theory-based reliability metrics (posbist reliability and uncertainty-theory-based reliability metrics (belief reliability. It is pointed out that a qualified reliability metric that is able to consider the effect of epistemic uncertainty needs to (1 compensate the conservatism in the estimations of the component-level reliability metrics caused by epistemic uncertainty, and (2 satisfy the duality axiom, otherwise it might lead to paradoxical and confusing results in engineering applications. The five commonly used non-probabilistic reliability metrics are compared in terms of these two properties, and the comparison can serve as a basis for the selection of the appropriate reliability metrics.

  18. Reliability-based inspection planning of 20MW offshore wind turbine jacket

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    2018-01-01

    This paper presents the application of a risk and reliability based inspection planning framework (RBI) for the InnWind 20MW reference wind turbine jacket sub-structure. A detailed fracture mechanics based fatigue crack growth model is developed and used as basis to derive optimal inspection plans...

  19. Reliability Approach of a Compressor System using Reliability Block ...

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... This paper presents a reliability analysis of such a system using reliability ... Keywords-compressor system, reliability, reliability block diagram, RBD .... the same structure has been kept with the three subsystems: air flow, oil flow and .... and Safety in Engineering Design", Springer, 2009. [3] P. O'Connor ...

  20. Frontiers of reliability

    CERN Document Server

    Basu, Asit P; Basu, Sujit K

    1998-01-01

    This volume presents recent results in reliability theory by leading experts in the world. It will prove valuable for researchers, and users of reliability theory. It consists of refereed invited papers on a broad spectrum of topics in reliability. The subjects covered include Bayesian reliability, Bayesian reliability modeling, confounding in a series system, DF tests, Edgeworth approximation to reliability, estimation under random censoring, fault tree reduction for reliability, inference about changes in hazard rates, information theory and reliability, mixture experiment, mixture of Weibul

  1. Reliability of pelvic floor measurements on three- and four-dimensional ultrasound during and after first pregnancy: implications for training.

    Science.gov (United States)

    van Veelen, G A; Schweitzer, K J; van der Vaart, C H

    2013-11-01

    To evaluate the reliability of measurements of the levator hiatus and levator-urethra gap (LUG) using three/four-dimensional (3D/4D) transperineal ultrasound in women during their first pregnancy and 6 months postpartum, and to assess the learning process for these measurements. An inexperienced observer was taught to perform measurements of the levator hiatus and LUG by an experienced observer. After training, 3D/4D ultrasound volume datasets of 40 women in the first trimester were analyzed by these two observers. Another training session then took place and both observers repeated the analyses of the same volume datasets. Finally, analyses of 40 volume datasets of the women 6 months postpartum were performed by both observers. Intra- and interobserver reliability were determined by intraclass correlation coefficients (ICC) with 95% CIs. For levator hiatal measurements, in the women during their first pregnancy the interobserver reliability was substantial to almost perfect after both the first and second training session (ICC, 0.62-0.83 and 0.71-0.89, respectively, for anteroposterior diameter, transverse diameter and area at rest, on contraction and on Valsalva) and the intraobserver reliability was substantial to almost perfect for both observers. For these measurements performed once the women had delivered, interobserver reliability was moderate to almost perfect. For LUG measurements performed during pregnancy, interobserver reliability was slight to moderate after the first training session (ICC, 0.14-0.54), but improved after the second training session (ICC, 0.38-0.71), and intraobserver reliability was moderate to substantial for the experienced observer and slight to moderate for the inexperienced observer. For these measurements performed when the women had delivered, interobserver reliability was fair to moderate. The levator hiatus and LUG can be measured reliably using 3D/4D ultrasound in primigravid and primiparous women. The technique to measure

  2. Prostaglandin E2 stimulates normal bronchial epithelial cell growth through induction of c-Jun and PDK1, a kinase implicated in oncogenesis.

    Science.gov (United States)

    Fan, Yu; Wang, Ye; Wang, Ke

    2015-12-18

    Cyclooxygenase-2-derived prostaglandin E2 (PGE2), a bioactive eicosanoid, has been implicated in many biological processes including reproduction, inflammation and tumor growth. We previously showed that PGE2 stimulated lung cancer cell growth and progression through PGE2 receptor EP2/EP4-mediated kinase signaling pathways. However, the role of PGE2 in controlling lung airway epithelial cell phenotype remains unknown. We evaluated the effects of c-Jun and 3-phosphoinositede dependent protein kinase-1 (PDK1) in mediating epithelial cell hyperplasia induced by PGE2. The bronchial epithelial cell lines BEAS-2B and HBEc14-KT were cultured and then treated with PGE2. PDK1 small interfering RNA (siRNA) and a PDK1 inhibitor, an antagonist of the PGE2 receptor subtype EP4 and EP4 siRNA, c-Jun siRNA, and overexpressions of c-Jun and PDK1 have been used to evaluate the effects on cell proliferation. We demonstrated that PGE2 increased normal bronchial epithelial cell proliferation through induction of PDK1, an ankyrin repeat-containing Ser/Thr kinase implicated in the induction of apoptosis and the suppression of tumor growth. PDK1 siRNA and a PDK1 inhibitor blocked the effects of PGE2 on normal cell growth. The PGE2-induced PDK1 expression was blocked by an antagonist of the PGE2 receptor subtype EP4 and by EP4 siRNA. In addition, we showed that induction of PDK1 by PGE2 was associated with induction of the transcription factor, c-Jun protein. Silencing of c-Jun using siRNA and point mutations of c-Jun sites in the PDK1 gene promoter resulted in blockade of PDK1 expression and promoter activity induced by PGE2. In contrast, overexpression of c-Jun induced PDK1 gene promoter activity and expression followed increased cell proliferation. PGE2 increases normal bronchial epithelial cell proliferation through increased PDK1 gene expression that is dependent on EP4 and induction of c-Jun. Therewith, our data suggest a new role of c-Jun and PDK1 in mediating epithelial cell

  3. System Reliability Engineering

    International Nuclear Information System (INIS)

    Lim, Tae Jin

    2005-02-01

    This book tells of reliability engineering, which includes quality and reliability, reliability data, importance of reliability engineering, reliability and measure, the poisson process like goodness of fit test and the poisson arrival model, reliability estimation like exponential distribution, reliability of systems, availability, preventive maintenance such as replacement policies, minimal repair policy, shock models, spares, group maintenance and periodic inspection, analysis of common cause failure, and analysis model of repair effect.

  4. A comparative study of the probabilistic fracture mechanics and the stochastic Markovian process approaches for structural reliability assessment

    Energy Technology Data Exchange (ETDEWEB)

    Stavrakakis, G.; Lucia, A.C.; Solomos, G. (Commission of the European Communities, Ispra (Italy). Joint Research Centre)

    1990-01-01

    The two computer codes COVASTOL and RELIEF, developed for the modeling of cumulative damage processes in the framework of probabilistic structural reliability, are compared. They are based respectively on the randomisation of a differential crack growth law and on the theory of discrete Markov processes. The codes are applied for fatigue crack growth predictions using two sets of data of crack propagation curves from specimens. The results are critically analyzed and an extensive discussion follows on the merits and limitations of each code. Their transferability for the reliability assessment of real structures is investigated. (author).

  5. Lifetime validation of high-reliability (>30,000hr) rotary cryocoolers for specific customer profiles

    Science.gov (United States)

    Cauquil, Jean-Marc; Seguineau, Cédric; Vasse, Christophe; Raynal, Gaetan; Benschop, Tonny

    2018-05-01

    The cooler reliability is a major performance requested by the customers, especially for 24h/24h applications, which are a growing market. Thales has built a reliability policy based on accelerate ageing and tests to establish a robust knowledge on acceleration factors. The current trend seems to prove that the RM2 mean time to failure is now higher than 30,000hr. Even with accelerate ageing; the reliability growth becomes hardly manageable for such large figures. The paper focuses on these figures and comments the robustness of such a method when projections over 30,000hr of MTTF are needed.

  6. A reliability simulation language for reliability analysis

    International Nuclear Information System (INIS)

    Deans, N.D.; Miller, A.J.; Mann, D.P.

    1986-01-01

    The results of work being undertaken to develop a Reliability Description Language (RDL) which will enable reliability analysts to describe complex reliability problems in a simple, clear and unambiguous way are described. Component and system features can be stated in a formal manner and subsequently used, along with control statements to form a structured program. The program can be compiled and executed on a general-purpose computer or special-purpose simulator. (DG)

  7. A study of operational and testing reliability in software reliability analysis

    International Nuclear Information System (INIS)

    Yang, B.; Xie, M.

    2000-01-01

    Software reliability is an important aspect of any complex equipment today. Software reliability is usually estimated based on reliability models such as nonhomogeneous Poisson process (NHPP) models. Software systems are improving in testing phase, while it normally does not change in operational phase. Depending on whether the reliability is to be predicted for testing phase or operation phase, different measure should be used. In this paper, two different reliability concepts, namely, the operational reliability and the testing reliability, are clarified and studied in detail. These concepts have been mixed up or even misused in some existing literature. Using different reliability concept will lead to different reliability values obtained and it will further lead to different reliability-based decisions made. The difference of the estimated reliabilities is studied and the effect on the optimal release time is investigated

  8. Human reliability

    International Nuclear Information System (INIS)

    Embrey, D.E.

    1987-01-01

    Concepts and techniques of human reliability have been developed and are used mostly in probabilistic risk assessment. For this, the major application of human reliability assessment has been to identify the human errors which have a significant effect on the overall safety of the system and to quantify the probability of their occurrence. Some of the major issues within human reliability studies are reviewed and it is shown how these are applied to the assessment of human failures in systems. This is done under the following headings; models of human performance used in human reliability assessment, the nature of human error, classification of errors in man-machine systems, practical aspects, human reliability modelling in complex situations, quantification and examination of human reliability, judgement based approaches, holistic techniques and decision analytic approaches. (UK)

  9. The art of progressive censoring applications to reliability and quality

    CERN Document Server

    Balakrishnan, N

    2014-01-01

    This monograph offers a thorough and updated guide to the theory and methods of progressive censoring, an area that has experienced tremendous growth in recent years. Progressive censoring, originally proposed in the 1950s, is an efficient method of handling samples from industrial experiments involving lifetimes of units that have either failed or censored in a progressive fashion during the life test, with many practical applications to reliability and quality. Key topics and features: Data sets from the literature as well as newly simulated data sets are used to illustrate concepts throughout the text Emphasis on real-life applications to life testing, reliability, and quality control Discussion of parametric and nonparametric inference Coverage of experimental design with optimal progressive censoring The Art of Progressive Censoring is a valuable reference for graduate students, researchers, and practitioners in applied statistics, quality control, life testing, and reliability. With its accessible style...

  10. Reliability Calculations

    DEFF Research Database (Denmark)

    Petersen, Kurt Erling

    1986-01-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

  11. Reliability considerations of a fuel cell backup power system for telecom applications

    Science.gov (United States)

    Serincan, Mustafa Fazil

    2016-03-01

    A commercial fuel cell backup power unit is tested in real life operating conditions at a base station of a Turkish telecom operator. The fuel cell system responds to 256 of 260 electric power outages successfully, providing the required power to the base station. Reliability of the fuel cell backup power unit is found to be 98.5% at the system level. On the other hand, a qualitative reliability analysis at the component level is carried out. Implications of the power management algorithm on reliability is discussed. Moreover, integration of the backup power unit to the base station ecosystem is reviewed in the context of reliability. Impact of inverter design on the stability of the output power is outlined. Significant current harmonics are encountered when a generic inverter is used. However, ripples are attenuated significantly when a custom design inverter is used. Further, fault conditions are considered for real world case studies such as running out of hydrogen, a malfunction in the system, or an unprecedented operating scheme. Some design guidelines are suggested for hybridization of the backup power unit for an uninterrupted operation.

  12. Semiconductor measurement technology: reliability technology for cardiac pacemakers 2: a workshop report, 1976

    International Nuclear Information System (INIS)

    Schafft, H.A.

    1977-01-01

    Summaries are presented of 12 invited talks on the following topics: the procurement and assurance of high reliability electronic parts, leak rate and moisture measurements, pacemaker batteries, and pacemaker leads. The workshop, second in a series, was held in response to strong interest expressed by the pacemaker community to address technical questions relevant to the enhancement and assurance of cardiac pacemaker reliability. Discussed at the workshop were a process validation wafer concept for assuring process uniformity in device chips; screen tests for assuring reliable electronic parts; reliability prediction; reliability comparison of semiconductor technologies; mechanisms of short-circuiting dendritic growths; details of helium and radioisotope leak test methods; a study to correlate package leak rates, as measured with test gasses, and actual moisture infusion; battery life prediction; microcalorimetric measurements to nondestructively evaluate batteries for pacemakers; and an engineer's and a physician's view of the present status of pacemaker leads. References are included with most of the reports

  13. MDP: Reliable File Transfer for Space Missions

    Science.gov (United States)

    Rash, James; Criscuolo, Ed; Hogie, Keith; Parise, Ron; Hennessy, Joseph F. (Technical Monitor)

    2002-01-01

    This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of the Multicast Dissemination Protocol (MDP) to space missions to reliably transfer files. This work builds on previous work by the OMNI project to apply Internet communication technologies to space communication. The goal of this effort is to provide an inexpensive, reliable, standard, and interoperable mechanism for transferring files in the space communication environment. Limited bandwidth, noise, delay, intermittent connectivity, link asymmetry, and one-way links are all possible issues for space missions. Although these are link-layer issues, they can have a profound effect on the performance of transport and application level protocols. MDP, a UDP-based reliable file transfer protocol, was designed for multicast environments which have to address these same issues, and it has done so successfully. Developed by the Naval Research Lab in the mid 1990's, MDP is now in daily use by both the US Post Office and the DoD. This paper describes the use of MDP to provide automated end-to-end data flow for space missions. It examines the results of a parametric study of MDP in a simulated space link environment and discusses the results in terms of their implications for space missions. Lessons learned are addressed, which suggest minor enhancements to the MDP user interface to add specific features for space mission requirements, such as dynamic control of data rate, and a checkpoint/resume capability. These are features that are provided for in the protocol, but are not implemented in the sample MDP application that was provided. A brief look is also taken at the status of standardization. A version of MDP known as NORM (Neck Oriented Reliable Multicast) is in the process of becoming an IETF standard.

  14. Surfactant-Mediated Growth Revisited

    International Nuclear Information System (INIS)

    Meyerheim, H. L.; Sander, D.; Popescu, R.; Pan, W.; Kirschner, J.; Popa, I.

    2007-01-01

    The x-ray structure analysis of the oxygen-surfactant-mediated growth of Ni on Cu(001) identifies up to 0.15 monolayers of oxygen in subsurface octahedral sites. This questions the validity of the general view that surfactant oxygen floats on top of the growing Ni film. Rather, the surfactant action is ascribed to an oxygen-enriched zone extending over the two topmost layers. Surface stress measurements support this finding. Our results have important implications for the microscopic understanding of surfactant-mediated growth and the change of the magnetic anisotropy of the Ni films

  15. Reliability in the utility computing era: Towards reliable Fog computing

    DEFF Research Database (Denmark)

    Madsen, Henrik; Burtschy, Bernard; Albeanu, G.

    2013-01-01

    This paper considers current paradigms in computing and outlines the most important aspects concerning their reliability. The Fog computing paradigm as a non-trivial extension of the Cloud is considered and the reliability of the networks of smart devices are discussed. Combining the reliability...... requirements of grid and cloud paradigms with the reliability requirements of networks of sensor and actuators it follows that designing a reliable Fog computing platform is feasible....

  16. Business ethics and economic growth: An empirical analysis for Turkish economy

    Directory of Open Access Journals (Sweden)

    Ekrem Erdem

    2015-12-01

    Full Text Available Purpose – The roots of the science of modern economics are originated from the ideas of Adam Smith who is not a pure economist but a moralist-philosopher. Basic concepts in the Wealth of Nations which is perceived as the hand book of economics depend on the arguments that Adam Smith suggests in his Theory of Moral Sentiments. In this theory, business ethics as a part of the Law of Sympathy appears as one of the factors that provide the invisible hand to operate properly. In light of this property, it is possible to assume business ethics as one of the components of the market mechanism. In this context, this study aims to analyse the link between business ethics and economic growth in the Turkish economy. Design/methodology/approach – The study employs bounced cheques and protested bonds for representing the degradation of business ethics and tries to show how this degradation affects economic growth in the Turkish economy for the period 1988-2013. Findings – Either illustrative or empirical results show that business ethics is an important determinant of economic growth in the Turkish economy and damaging it negatively effects the growth rate of the economy. Research limitations/implications – One of the most restrictive things conducting the present empirical analysis is the lack of various and longer data sets. Using different indicators in terms of business ethics with longer time span will definitely increase the reliability of the study. However, in the current form, results imply a policy that is capable of limiting the failures of business ethics may boost the Turkish economy up. Originality/value – The results tend to support the close link between business ethics and economic growth.

  17. Dependent systems reliability estimation by structural reliability approach

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2014-01-01

    Estimation of system reliability by classical system reliability methods generally assumes that the components are statistically independent, thus limiting its applicability in many practical situations. A method is proposed for estimation of the system reliability with dependent components, where...... the leading failure mechanism(s) is described by physics of failure model(s). The proposed method is based on structural reliability techniques and accounts for both statistical and failure effect correlations. It is assumed that failure of any component is due to increasing damage (fatigue phenomena...... identification. Application of the proposed method can be found in many real world systems....

  18. Confronting New Demands : Inclusive Growth, Inclusive Trade ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Confronting New Demands : Inclusive Growth, Inclusive Trade. Policymakers, businesspeople and civil society advocates need evidence-based research to react ... understood implications, such as labour standards and intellectual property; ...

  19. The CHARGE Association: Implications for Teachers.

    Science.gov (United States)

    Jones, Thomas W.; Dunne, Michele T.

    1988-01-01

    CHARGE association is described as a diagnostic label for a group of congenital malformations, including coloboma, heart defects, atresia choanae, retarded postnatal growth/central nervous system defects, genital hypoplasia, and ear deformities. Etiology and characteristics of the CHARGE association are discussed, along with implications for…

  20. Cassava production and consumption: Health implications

    African Journals Online (AJOL)

    Mr A. O. Akinpelu

    HEALTH IMPLICATIONS OF CASSAVA PRODUCTION AND CONSUMPTION. AKINPELU, A.O. ... huge potential for the export market (Egesi et al., 2007). In urban areas ... farmer's/ household income and economic growth. Stakeholders in ..... dissertation submitted to the school of graduate studies in partial fulfilment of the.

  1. Analyzing the reliability of shuffle-exchange networks using reliability block diagrams

    International Nuclear Information System (INIS)

    Bistouni, Fathollah; Jahanshahi, Mohsen

    2014-01-01

    Supercomputers and multi-processor systems are comprised of thousands of processors that need to communicate in an efficient way. One reasonable solution would be the utilization of multistage interconnection networks (MINs), where the challenge is to analyze the reliability of such networks. One of the methods to increase the reliability and fault-tolerance of the MINs is use of various switching stages. Therefore, recently, the reliability of one of the most common MINs namely shuffle-exchange network (SEN) has been evaluated through the investigation on the impact of increasing the number of switching stage. Also, it is concluded that the reliability of SEN with one additional stage (SEN+) is better than SEN or SEN with two additional stages (SEN+2), even so, the reliability of SEN is better compared to SEN with two additional stages (SEN+2). Here we re-evaluate the reliability of these networks where the results of the terminal, broadcast, and network reliability analysis demonstrate that SEN+ and SEN+2 continuously outperform SEN and are very alike in terms of reliability. - Highlights: • The impact of increasing the number of stages on reliability of MINs is investigated. • The RBD method as an accurate method is used for the reliability analysis of MINs. • Complex series–parallel RBDs are used to determine the reliability of the MINs. • All measures of the reliability (i.e. terminal, broadcast, and network reliability) are analyzed. • All reliability equations will be calculated for different size N×N

  2. Mechanistic model for microbial growth on hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Mallee, F M; Blanch, H W

    1977-12-01

    Based on available information describing the transport and consumption of insoluble alkanes, a mechanistic model is proposed for microbial growth on hydrocarbons. The model describes the atypical growth kinetics observed, and has implications in the design of large scale equipment for single cell protein (SCP) manufacture from hydrocarbons. The model presents a framework for comparison of the previously published experimental kinetic data.

  3. Postnatal growth, age estimation and development of foraging ...

    Indian Academy of Sciences (India)

    Unknown

    growth after the first year (Kunz and Stern 1995). The values of the lengths of forearm and epiphyseal gap dur- ing their linear phases of growth increased during the preflight period and decreased during the postflight period, and were reliable for deriving equations to esti- mate the age of young bats (e.g. Kunz and Robson ...

  4. Completeness and reliability of mortality data in Viet Nam: Implications for the national routine health management information system.

    Science.gov (United States)

    Hong, Tran Thi; Phuong Hoa, Nguyen; Walker, Sue M; Hill, Peter S; Rao, Chalapati

    2018-01-01

    Mortality statistics form a crucial component of national Health Management Information Systems (HMIS). However, there are limitations in the availability and quality of mortality data at national level in Viet Nam. This study assessed the completeness of recorded deaths and the reliability of recorded causes of death (COD) in the A6 death registers in the national routine HMIS in Viet Nam. 1477 identified deaths in 2014 were reviewed in two provinces. A capture-recapture method was applied to assess the completeness of the A6 death registers. 1365 household verbal autopsy (VA) interviews were successfully conducted, and these were reviewed by physicians who assigned multiple and underlying cause of death (UCOD). These UCODs from VA were then compared with the CODs recorded in the A6 death registers, using kappa scores to assess the reliability of the A6 death register diagnoses. The overall completeness of the A6 death registers in the two provinces was 89.3% (95%CI: 87.8-90.8). No COD recorded in the A6 death registers demonstrated good reliability. There is very low reliability in recording of cardiovascular deaths (kappa for stroke = 0.47 and kappa for ischaemic heart diseases = 0.42) and diabetes (kappa = 0.33). The reporting of deaths due to road traffic accidents, HIV and some cancers are at a moderate level of reliability with kappa scores ranging between 0.57-0.69 (pViet Nam.

  5. Reliability data banks

    International Nuclear Information System (INIS)

    Cannon, A.G.; Bendell, A.

    1991-01-01

    Following an introductory chapter on Reliability, what is it, why it is needed, how it is achieved and measured, the principles of reliability data bases and analysis methodologies are the subject of the next two chapters. Achievements due to the development of data banks are mentioned for different industries in the next chapter, FACTS, a comprehensive information system for industrial safety and reliability data collection in process plants are covered next. CREDO, the Central Reliability Data Organization is described in the next chapter and is indexed separately, as is the chapter on DANTE, the fabrication reliability Data analysis system. Reliability data banks at Electricite de France and IAEA's experience in compiling a generic component reliability data base are also separately indexed. The European reliability data system, ERDS, and the development of a large data bank come next. The last three chapters look at 'Reliability data banks, - friend foe or a waste of time'? and future developments. (UK)

  6. An Introduction To Reliability

    International Nuclear Information System (INIS)

    Park, Kyoung Su

    1993-08-01

    This book introduces reliability with definition of reliability, requirement of reliability, system of life cycle and reliability, reliability and failure rate such as summary, reliability characteristic, chance failure, failure rate which changes over time, failure mode, replacement, reliability in engineering design, reliability test over assumption of failure rate, and drawing of reliability data, prediction of system reliability, conservation of system, failure such as summary and failure relay and analysis of system safety.

  7. The prediction of reliability and residual life of reactor pressure components

    International Nuclear Information System (INIS)

    Nemec, J.; Antalovsky, S.

    1978-01-01

    The paper deals with the problem of PWR pressure components reliability and residual life evaluation and prediction. A physical model of damage cumulation which serves as a theoretical basis for all considerations presents two major aspects. The first one describes the dependence of the degree of damage in the crack leading-edge in pressure components on the reactor system load-time history, i.e. on the number of transient loads. Both stages, fatigue crack initiation and growth through the wall until the critical length is reached, are investigated. The crack is supposed to initiate at the flaws in a strength weld joint or in the bimetallic weld of the base ferritic steel and the austenitic stainless overlay cladding. The growth rates of developed cracks are analysed in respect to different load-time histories. Important cyclic properties of some steels are derived from the low-cycle fatigue theory. The second aspect is the load-time history-dependent process of precipitation, deformation and radiation aging, characterized entirely by the critical crack-length value mentioned above. The fracture point, defined by the equation ''crack-length=critical value'' and hence the residual life, can be evaluated using this model and verified by in-service inspection. The physical model described is randomized by considering all the parameters of the model as random. Monte Carlo methods are applied and fatigue crack initiation and growth is simulated. This permits evaluation of the reliability and residual life of the component. The distributions of material and load-time history parameters are needed for such simulation. Both the deterministic and computer-simulated probabilistic predictions of reliability and residual life are verified by prior-to-failure sequential testing of data coming from in-service NDT periodical inspections. (author)

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

    Science.gov (United States)

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

    2017-04-01

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

  9. Reliability analysis of the solar array based on Fault Tree Analysis

    International Nuclear Information System (INIS)

    Wu Jianing; Yan Shaoze

    2011-01-01

    The solar array is an important device used in the spacecraft, which influences the quality of in-orbit operation of the spacecraft and even the launches. This paper analyzes the reliability of the mechanical system and certifies the most vital subsystem of the solar array. The fault tree analysis (FTA) model is established according to the operating process of the mechanical system based on DFH-3 satellite; the logical expression of the top event is obtained by Boolean algebra and the reliability of the solar array is calculated. The conclusion shows that the hinges are the most vital links between the solar arrays. By analyzing the structure importance(SI) of the hinge's FTA model, some fatal causes, including faults of the seal, insufficient torque of the locking spring, temperature in space, and friction force, can be identified. Damage is the initial stage of the fault, so limiting damage is significant to prevent faults. Furthermore, recommendations for improving reliability associated with damage limitation are discussed, which can be used for the redesigning of the solar array and the reliability growth planning.

  10. Reliability analysis of the solar array based on Fault Tree Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jianing; Yan Shaoze, E-mail: yansz@mail.tsinghua.edu.cn [State Key Laboratory of Tribology, Department of Precision Instruments and Mechanology, Tsinghua University,Beijing 100084 (China)

    2011-07-19

    The solar array is an important device used in the spacecraft, which influences the quality of in-orbit operation of the spacecraft and even the launches. This paper analyzes the reliability of the mechanical system and certifies the most vital subsystem of the solar array. The fault tree analysis (FTA) model is established according to the operating process of the mechanical system based on DFH-3 satellite; the logical expression of the top event is obtained by Boolean algebra and the reliability of the solar array is calculated. The conclusion shows that the hinges are the most vital links between the solar arrays. By analyzing the structure importance(SI) of the hinge's FTA model, some fatal causes, including faults of the seal, insufficient torque of the locking spring, temperature in space, and friction force, can be identified. Damage is the initial stage of the fault, so limiting damage is significant to prevent faults. Furthermore, recommendations for improving reliability associated with damage limitation are discussed, which can be used for the redesigning of the solar array and the reliability growth planning.

  11. Low climate stabilisation under diverse growth and convergence scenarios

    International Nuclear Information System (INIS)

    Markandya, A.; González-Eguino, M.; Criqui, P.; Mima, S.

    2014-01-01

    In the last decade a number of papers have analysed the consequences of achieving the greenhouse gas concentration levels necessary to maintain global temperature increases below 2 °C above preindustrial levels. Most models and scenarios assume that future trends in global GDP will be similar to the growth experienced in the past century, which would imply multiplying current output by about 19 times in the 21st century. However, natural resource and environmental constraints suggest that future global economic growth may not be so high. Furthermore, the environmental implications of such growth depend on how it is distributed across countries. This paper studies the implications on GHG abatement policies of low global GDP growth and high convergence levels in GDP per capita across countries. A partial equilibrium model (POLES) of the world's energy system is used to provide detailed projections up to 2050 for the different regions of the world. The results suggest that while low stabilisation could be technically feasible and economically viable for the world in all the scenarios considered, it is more likely to occur with more modest global growth. However, that will imply higher global abatement costs relative to GDP. Convergence in living standards on the other hand places greater pressures in terms of the required reduction in emissions. In general we find that there are major differences between regions in terms of the size and the timing of abatement costs and economic impact. - Highlights: • We study the implications of GDP growth and convergence on climate stabilisation. • A partial equilibrium model (POLES) of the world's energy system is used. • Low climate stabilisation is technically feasible and economically viable. • Low stabilisation is more likely to occur with more modest global growth. • Convergence places pressure in terms of the required reduction in emissions

  12. Business of reliability

    Science.gov (United States)

    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.

  13. Factors that determine the evolution of high-growth businesses

    Directory of Open Access Journals (Sweden)

    Oriol Amat

    2013-09-01

    Full Text Available Objective: The study herein discusses research aimed at elucidating the factors that contribute to a business’ ability to maintain high growth. Design/Methodology/Perspective: The database from the Iberian Balance Sheet Analysis System (SABI, from its initials in Spanish was used to identify 250 industrial Catalonian businesses with high growth during 2004-2007. These companies participated in a survey on strategies and management practices; in 2013, they were re-analyzed to investigate the factors that contributed to continued growth for certain companies. Contributions: Through diverse statistical techniques, business policies related to quality, innovation, internationalization and finance were shown to influence business growth and sustainability over time. Limitations of the Research: This study focuses on industrial businesses at least ten years old in Catalonia; thus, the conclusions may differ in other geographic locations and economic sectors, as well as for smaller businesses. Practical Implications: Because growth is a measure of business success, identifying variables that contribute to high growth and its sustainability is helpful for businesses that seek to adopt effective policies. Social Implications: Generating employment is one of the primary contributions by high-growth businesses. For years with high unemployment, authorities may be interested in corporate policies that strengthen high-growth businesses. Originality/Added Value: High-growth businesses have been studied throughout the world, but this is the first study to investigate the evolution of businesses after a high-growth phase.

  14. Reliability calculations

    International Nuclear Information System (INIS)

    Petersen, K.E.

    1986-03-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)

  15. Reliability of one-repetition maximum performance in people with chronic heart failure.

    Science.gov (United States)

    Ellis, Rachel; Holland, Anne E; Dodd, Karen; Shields, Nora

    2018-02-24

    Evaluate intra-rater and inter-rater reliability of the one-repetition maximum strength test in people with chronic heart failure. Intra-rater and inter-rater reliability study. A public tertiary hospital in northern metropolitan Melbourne. Twenty-four participants (nine female, mean age 71.8 ± 13.1 years) with mild to moderate heart failure of any aetiology. Lower limb strength was assessed by determining the maximum weight that could be lifted using a leg press. Intra-rater reliability was tested by one assessor on two separate occasions . Inter-rater reliability was tested by two assessors in random order. Intra-class correlation coefficients and 95% confidence intervals were calculated. Bland and Altman analyses were also conducted, including calculation of mean differences between measures ([Formula: see text]) and limits of agreement . Ten intra-rater and 21 inter-rater assessments were completed. Excellent intra-rater (intra-class correlation coefficient 2,1 0.96) and inter-rater (intra-class correlation coefficient 2,1 0.93) reliability was found. Intra-rater assessment showed less variability (mean difference 4.5 kg, limits of agreement -8.11 to 17.11 kg) than inter-rater agreement (mean difference -3.81 kg, limits of agreement -23.39 to 15.77 kg). One-repetition maximum determined using a leg press is a reliable measure in people with heart failure. Given its smaller limits of agreement, intra-rater testing is recommended. Implications for Rehabilitation Using a leg press to determine a one-repetition maximum we were able to demonstrate excellent inter-rater and intra-rater reliability using an intra-class correlation coefficient. The Bland and Altman levels of agreement were wide for inter-rater reliability and so we recommend using one assessor if measuring change in strength within an individual over time.

  16. Nigerian population growth and its implications for economic development.

    Science.gov (United States)

    Okpala, A O

    1990-12-01

    The population of Nigeria is growing at a rate of 3.75%/year indicating a doubling of the population every 22 years. Demographers estimated the population to be 91,178,000 in 1985. Even though population density is high (288 people/square mile), it is not equally distributed. It is highest in the south and southwest urban areas such as Lagos (1045 people/square mile) and lowest in the northeast (75 people/square mile). Moreover rural-urban migration is growing. A major reason for rural-urban migration is the dual nature of the economy in Nigeria. In urban areas, economic development brings about higher standards of living, but, in rural areas, a subsistence economy predominates. This coupled with rapid population growth results in small or no growth in per capita income. Only if the government were to integrate redistribution policies into complete economic development plans should it consider redistributing the population. It should stress rural development (e.g., incentives for firms to set up in rural areas). Further it should move some government offices to rural areas. The government also needs to adopt population policies encouraging the lowering of fertility levels. If it were to provide education through the secondary and prevocational education level free of charge, educated women will lower their fertility. Sex education should be included in the curriculum. Further the government must play an active role in family planning programs, especially educating rural women about family planning. It should also use the mass media to promote small family size, but it should not dictate family size. It also needs to recognize that population growth puts much pressure on the environment. For example, population growth causes soil erosion, nutrient exhaustion, rapid deforestation, and other problems which render the land unusable for agriculture.

  17. Fetal deficiency of Lin28 programs life-long aberrations in growth and glucose metabolism

    Science.gov (United States)

    Shinoda, Gen; Shyh-Chang, Ng; de Soysa, T. Yvanka; Zhu, Hao; Seligson, Marc T.; Shah, Samar P.; Abo-Sido, Nora; Yabuuchi, Akiko; Hagan, John P.; Gregory, Richard I.; Asara, John M.; Cantley, Lewis C.; Moss, Eric G.; Daley, George Q.

    2013-01-01

    LIN28A/B are RNA binding proteins implicated by genetic association studies in human growth and glucose metabolism. Mice with ectopic over-expression of Lin28a have shown related phenotypes. Here we describe the first comprehensive analysis of the physiologic consequences of Lin28a and Lin28b deficiency in knockout (KO) mice. Lin28a/b-deficiency led to dwarfism starting at different ages, and compound gene deletions showed a cumulative dosage effect on organismal growth. Conditional gene deletion at specific developmental stages revealed that fetal but neither neonatal nor adult deficiency resulted in growth defects and aberrations in glucose metabolism. Tissue-specific KO mice implicated skeletal muscle-deficiency in the abnormal programming of adult growth and metabolism. The effects of Lin28b KO can be rescued by Tsc1 haplo-insufficiency in skeletal muscles. Our data implicate fetal expression of Lin28a/b in the regulation of life-long effects on metabolism and growth, and demonstrate that fetal Lin28b acts at least in part via mTORC1 signaling. PMID:23666760

  18. Effect of young maternal age and skeletal growth on placental growth and development.

    Science.gov (United States)

    Hayward, C E; Greenwood, S L; Sibley, C P; Baker, P N; Jones, R L

    2011-12-01

    Teenagers are susceptible to delivering small-for-gestational-age infants. Previous studies implicate continued skeletal growth as a contributory factor, and impaired placental development was the primary cause of fetal growth restriction in growing adolescent sheep. The aims of this study were to examine the impact of young maternal age and growth on placental development. Placentas were collected from 31 teenagers, of which 12 were growing and 17 non-growing based on knee height measurements. An adult control group (n = 12) was included. Placental weight and morphometric measurements of villous, syncytiotrophoblast, fibrin and vessel areas, as well as indices of proliferation and apoptosis, were analysed in relation to maternal growth and age. Growing teenagers had a higher birthweight:placental weight ratio than non-growing teenagers (p adult and teenage pregnancies. Maternal smoking, a potential confounding factor, did not exert a major influence on the placental parameters examined, except for a stimulatory effect on placental proliferation (p development, and is consistent with our recent observations that maternal growth was not detrimental to fetal growth. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. 2002 reliability report on the French power system; Bilan 2002 de la surete du systeme electrique francais

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Ensuring the reliability of the power system is one of the main responsibilities entrusted to RTE, the French transmission system operator, by the Act of February 10, 2000. Reliability must be maintained, both now and in the future. This means that RTE is required to: ensure the normal operation of the power system, limit the number of incidents and avoid major incidents, limit the consequences of major incidents when they do occur. By publishing a yearly reliability report on the French power system, RTE is clearly showing its ambition to encourage long-term supervision of all aspects of system reliability development. By this approach, RTE's intention is to help develop a reliability culture, by all the actors concerned (both RTE and network users) more aware of their role in establishing reliability, and by promoting reliability issues and comparisons with international transmission system operator associations (UCTE , ETSO ). The annual reliability report is drawn up around the following themes: a broad overview of changes in the internal and external environment that have implications for reliability, developments in the various elements that make up the reliability referential during the course of the year, developments on measures aimed at promoting reliability, in terms of equipment, organisation and human resources, lessons learned from events that took place over the year, the presentation of reliability-related indicators, RTE's control loop, and the developments under way at present.

  20. Endogenous Growth Paradigm. Implications for Economic Policy and Theory

    Directory of Open Access Journals (Sweden)

    Liviu-Catalin Moraru

    2006-12-01

    Full Text Available The role played by endogenous growth models in growth literature might be analyzed from two perspectives. In the first place, is it emphasized the necessity to replace the hypothesis of perfect competition with monopolistic competition in every mathematical model. Secondly, there is no scientific argument to accept the assumption of unconditional income convergence among countries. Taking into consideration empirical evidence and theoretical arguments, we tried to demonstrate that, once we accept the existence of increasing returns, there is only a little place for convergence all over the world. From this perspective, we can accept the hypothesis of convergence only for some categories of countries characterized by homogeneity as regards institutional arrangement and geographical position.

  1. Assuring the reliability of structural components - experimental data and non-destructive examination requirements

    International Nuclear Information System (INIS)

    Lucia, A.C.

    1984-01-01

    The probability of failure of a structural component can be estimated by either statistical methods or a probabilistic structural reliability approach (where the failure is seen as a level crossing of a damage stochastic process which develops in space and in time). The probabilistic approach has the advantage that it makes available not only an absolute value of the failure probability but also a lot of additional information. The disadvantage of the probabilistic approach is its complexity. It is discussed for the following situations: reliability of a structural component, material properties, data for fatigue crack growth evaluation, a bench mark exercise on reactor pressure vessel failure probability computation, and non-destructive examination for assuring a given level of structural reliability. (U.K.)

  2. Multiobjective Reliable Cloud Storage with Its Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Xiyang Liu

    2016-01-01

    Full Text Available Information abounds in all fields of the real life, which is often recorded as digital data in computer systems and treated as a kind of increasingly important resource. Its increasing volume growth causes great difficulties in both storage and analysis. The massive data storage in cloud environments has significant impacts on the quality of service (QoS of the systems, which is becoming an increasingly challenging problem. In this paper, we propose a multiobjective optimization model for the reliable data storage in clouds through considering both cost and reliability of the storage service simultaneously. In the proposed model, the total cost is analyzed to be composed of storage space occupation cost, data migration cost, and communication cost. According to the analysis of the storage process, the transmission reliability, equipment stability, and software reliability are taken into account in the storage reliability evaluation. To solve the proposed multiobjective model, a Constrained Multiobjective Particle Swarm Optimization (CMPSO algorithm is designed. At last, experiments are designed to validate the proposed model and its solution PSO algorithm. In the experiments, the proposed model is tested in cooperation with 3 storage strategies. Experimental results show that the proposed model is positive and effective. The experimental results also demonstrate that the proposed model can perform much better in alliance with proper file splitting methods.

  3. Reliability demonstration methodology for products with Gamma Process by optimal accelerated degradation testing

    International Nuclear Information System (INIS)

    Zhang, Chunhua; Lu, Xiang; Tan, Yuanyuan; Wang, Yashun

    2015-01-01

    For products with high reliability and long lifetime, accelerated degradation testing (ADT) may be adopted during product development phase to verify whether its reliability satisfies the predetermined level within feasible test duration. The actual degradation from engineering is usually a strictly monotonic process, such as fatigue crack growth, wear, and erosion. However, the method for reliability demonstration by ADT with monotonic degradation process has not been investigated so far. This paper proposes a reliability demonstration methodology by ADT for this kind of product. We first apply Gamma process to describe the monotonic degradation. Next, we present a reliability demonstration method by converting the required reliability level into allowable cumulative degradation in ADT and comparing the actual accumulative degradation with the allowable level. Further, we suggest an analytical optimal ADT design method for more efficient reliability demonstration by minimizing the asymptotic variance of decision variable in reliability demonstration under the constraints of sample size, test duration, test cost, and predetermined decision risks. The method is validated and illustrated with example on reliability demonstration of alloy product, and is applied to demonstrate the wear reliability within long service duration of spherical plain bearing in the end. - Highlights: • We present a reliability demonstration method by ADT for products with monotonic degradation process, which may be applied to verify reliability with long service life for products with monotonic degradation process within feasible test duration. • We suggest an analytical optimal ADT design method for more efficient reliability demonstration, which differs from the existed optimal ADT design for more accurate reliability estimation by different objective function and different constraints. • The methods are applied to demonstrate the wear reliability within long service duration of

  4. Reliability-based management of buried pipelines considering external corrosion defects

    Science.gov (United States)

    Miran, Seyedeh Azadeh

    -system. Sensitivity analysis is also performed to determine to which incorporated parameter(s) in the growth models reliability of the studied pipeline is most sensitive. The reliability analysis results suggest that newly generated defects should be considered in calculating failure probability, especially for prediction of long-term performance of the pipeline and also, impact of the statistical uncertainty in the model parameters is significant that should be considered in the reliability analysis. Finally, with the evaluated time-dependent failure probabilities, a life cycle-cost analysis is conducted to determine optimal inspection interval of studied pipeline. The expected total life-cycle costs consists construction cost and expected costs of inspections, repair, and failure. The repair is conducted when failure probability from any described failure mode exceeds pre-defined probability threshold after each inspection. Moreover, this study also investigates impact of repair threshold values and unit costs of inspection and failure on the expected total life-cycle cost and optimal inspection interval through a parametric study. The analysis suggests that a smaller inspection interval leads to higher inspection costs, but can lower failure cost and also repair cost is less significant compared to inspection and failure costs.

  5. Technical limitations of African prints and their implications

    African Journals Online (AJOL)

    User

    THEIR IMPLICATIONS ON GARMENT CONSTRUCTION IN. GHANA ... economic growth throughout the world. In. 2001, the sector ... and its exports represent 45 billion Euros, mak- ing it the world's ..... Unpublished BA Thesis,. College of Art ...

  6. Interactive reliability assessment using an integrated reliability data bank

    International Nuclear Information System (INIS)

    Allan, R.N.; Whitehead, A.M.

    1986-01-01

    The logical structure, techniques and practical application of a computer-aided technique based on a microcomputer using floppy disc Random Access Files is described. This interactive computational technique is efficient if the reliability prediction program is coupled directly to a relevant source of data to create an integrated reliability assessment/reliability data bank system. (DG)

  7. 76 FR 23222 - Electric Reliability Organization Interpretation of Transmission Operations Reliability

    Science.gov (United States)

    2011-04-26

    ....3d 1342 (DC Cir. 2009). \\5\\ Mandatory Reliability Standards for the Bulk-Power System, Order No. 693... Reliability Standards for the Bulk-Power System. Action: FERC-725A. OMB Control No.: 1902-0244. Respondents...] Electric Reliability Organization Interpretation of Transmission Operations Reliability AGENCY: Federal...

  8. A Reliable Measure of Information Security Awareness and the Identification of Bias in Responses

    Directory of Open Access Journals (Sweden)

    Agata McCormac

    2017-11-01

    Full Text Available The Human Aspects of Information Security Questionnaire (HAIS-Q is designed to measure Information Security Awareness. More specifically, the tool measures an individual’s knowledge, attitude, and self-reported behaviour relating to information security in the workplace. This paper reports on the reliability of the HAIS-Q, including test-retest reliability and internal consistency. The paper also assesses the reliability of three preliminary over-claiming items, designed specifically to complement the HAIS-Q, and identify those individuals who provide socially desirable responses. A total of 197 working Australians completed two iterations of the HAIS-Q and the over-claiming items, approximately 4 weeks apart. Results of the analysis showed that the HAIS-Q was externally reliable and internally consistent. Therefore, the HAIS-Q can be used to reliably measure information security awareness. Reliability testing on the preliminary over-claiming items was not as robust and further development is required and recommended. The implications of these findings mean that organisations can confidently use the HAIS-Q to not only measure the current state of employee information security awareness within their organisation, but they can also measure the effectiveness and impacts of training interventions, information security awareness programs and campaigns. The influence of cultural changes and the effect of security incidents can also be assessed.

  9. Reliability analysis for wind turbines with incomplete failure data collected from after the date of initial installation

    International Nuclear Information System (INIS)

    Guo Haitao; Watson, Simon; Tavner, Peter; Xiang Jiangping

    2009-01-01

    Reliability has an impact on wind energy project costs and benefits. Both life test data and field failure data can be used for reliability analysis. In wind energy industry, wind farm operators have greater interest in recording wind turbine operating data. However, field failure data may be tainted or incomplete, and therefore it needs a more general mathematical model and algorithms to solve the model. The aim of this paper is to provide a solution to this problem. A three-parameter Weibull failure rate function is discussed for wind turbines and the parameters are estimated by maximum likelihood and least squares. Two populations of German and Danish wind turbines are analyzed. The traditional Weibull failure rate function is also employed for comparison. Analysis shows that the three-parameter Weibull function can obtain more accuracy on reliability growth of wind turbines. This work will be helpful in the understanding of the reliability growth of wind energy systems as wind energy technologies evolving. The proposed three-parameter Weibull function is also applicable to the life test of the components that have been used for a period of time, not only in wind energy but also in other industries

  10. A dynamic discretization method for reliability inference in Dynamic Bayesian Networks

    International Nuclear Information System (INIS)

    Zhu, Jiandao; Collette, Matthew

    2015-01-01

    The material and modeling parameters that drive structural reliability analysis for marine structures are subject to a significant uncertainty. This is especially true when time-dependent degradation mechanisms such as structural fatigue cracking are considered. Through inspection and monitoring, information such as crack location and size can be obtained to improve these parameters and the corresponding reliability estimates. Dynamic Bayesian Networks (DBNs) are a powerful and flexible tool to model dynamic system behavior and update reliability and uncertainty analysis with life cycle data for problems such as fatigue cracking. However, a central challenge in using DBNs is the need to discretize certain types of continuous random variables to perform network inference while still accurately tracking low-probability failure events. Most existing discretization methods focus on getting the overall shape of the distribution correct, with less emphasis on the tail region. Therefore, a novel scheme is presented specifically to estimate the likelihood of low-probability failure events. The scheme is an iterative algorithm which dynamically partitions the discretization intervals at each iteration. Through applications to two stochastic crack-growth example problems, the algorithm is shown to be robust and accurate. Comparisons are presented between the proposed approach and existing methods for the discretization problem. - Highlights: • A dynamic discretization method is developed for low-probability events in DBNs. • The method is compared to existing approaches on two crack growth problems. • The method is shown to improve on existing methods for low-probability events

  11. 76 FR 23171 - Electric Reliability Organization Interpretations of Interconnection Reliability Operations and...

    Science.gov (United States)

    2011-04-26

    ... Reliability Standards for the Bulk-Power System, Order No. 693, FERC Stats. & Regs. ] 31,242, order on reh'g...-Power System reliability may request an interpretation of a Reliability Standard.\\7\\ The ERO's standards... information in its reliability assessments. The Reliability Coordinator must monitor Bulk Electric System...

  12. Coal consumption and economic growth in Taiwan

    International Nuclear Information System (INIS)

    Yang, H.Y.

    2000-01-01

    The purpose of this paper is to examine the causality issue between coal consumption and economic growth for Taiwan. The co-integration and Granger's causality test are applied to investigate the relationship between the two economic series. Results of the co-integration and Granger's causality test based on 1954--1997 Taiwan data show a unidirectional causality from economic growth to coal consumption with no feedback effects. Their major finding supports the neutrality hypothesis of coal consumption with respect to economic growth. Further, the finding has practical policy implications for decision makers in the area of macroeconomic planning, as coal conservation is a feasible policy with no damaging repercussions on economic growth

  13. Reliability issues and solutions for coding social communication performance in classroom settings.

    Science.gov (United States)

    Olswang, Lesley B; Svensson, Liselotte; Coggins, Truman E; Beilinson, Jill S; Donaldson, Amy L

    2006-10-01

    To explore the utility of time-interval analysis for documenting the reliability of coding social communication performance of children in classroom settings. Of particular interest was finding a method for determining whether independent observers could reliably judge both occurrence and duration of ongoing behavioral dimensions for describing social communication performance. Four coders participated in this study. They observed and independently coded 6 social communication behavioral dimensions using handheld computers. The dimensions were mutually exclusive and accounted for all verbal and nonverbal productions during a specified time frame. The technology allowed for coding frequency and duration for each entered code. Data were collected from 20 different 2-min video segments of children in kindergarten through 3rd-grade classrooms. Data were analyzed for interobserver and intraobserver agreements using time-interval sorting and Cohen's kappa. Further, interval size and total observation length were manipulated to determine their influence on reliability. The data revealed interval sorting and kappa to be a suitable method for examining reliability of occurrence and duration of ongoing social communication behavioral dimensions. Nearly all comparisons yielded medium to large kappa values; interval size and length of observation minimally affected results. Implications The analysis procedure described in this research solves a challenge in reliability: comparing coding by independent observers of both occurrence and duration of behaviors. Results indicate the utility of a new coding taxonomy and technology for application in online observations of social communication in a classroom setting.

  14. solveME: fast and reliable solution of nonlinear ME models

    DEFF Research Database (Denmark)

    Yang, Laurence; Ma, Ding; Ebrahim, Ali

    2016-01-01

    Background: Genome-scale models of metabolism and macromolecular expression (ME) significantly expand the scope and predictive capabilities of constraint-based modeling. ME models present considerable computational challenges: they are much (>30 times) larger than corresponding metabolic reconstr......Background: Genome-scale models of metabolism and macromolecular expression (ME) significantly expand the scope and predictive capabilities of constraint-based modeling. ME models present considerable computational challenges: they are much (>30 times) larger than corresponding metabolic...... reconstructions (M models), are multiscale, and growth maximization is a nonlinear programming (NLP) problem, mainly due to macromolecule dilution constraints. Results: Here, we address these computational challenges. We develop a fast and numerically reliable solution method for growth maximization in ME models...

  15. Evaluation of the ability of commercial wine yeasts to form biofilms (mats) and adhere to plastic: implications for the microbiota of the winery environment.

    Science.gov (United States)

    Tek, Ee Lin; Sundstrom, Joanna F; Gardner, Jennifer M; Oliver, Stephen G; Jiranek, Vladimir

    2018-02-01

    Commercially available active dried wine yeasts are regularly used by winemakers worldwide to achieve reliable fermentations and obtain quality wine. This practice has led to increased evidence of traces of commercial wine yeast in the vineyard, winery and uninoculated musts. The mechanism(s) that enables commercial wine yeast to persist in the winery environment and the influence to native microbial communities on this persistence is poorly understood. This study has investigated the ability of commercial wine yeasts to form biofilms and adhere to plastic. The results indicate that the biofilms formed by commercial yeasts consist of cells with a combination of different lifestyles (replicative and non-replicative) and growth modes including invasive growth, bud elongation, sporulation and a mat sectoring-like phenotype. Invasive growth was greatly enhanced on grape pulp regardless of strain, while adhesion on plastic varied between strains. The findings suggest a possible mechanism that allows commercial yeast to colonise and survive in the winery environment, which may have implications for the indigenous microbiota profile as well as the population profile in uninoculated fermentations if their dissemination is not controlled. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Material Selection for Cable Gland to Improved Reliability of the High-hazard Industries

    Science.gov (United States)

    Vashchuk, S. P.; Slobodyan, S. M.; Deeva, V. S.; Vashchuk, D. S.

    2018-01-01

    The sealed cable glands (SCG) are available to ensure safest connection sheathed single wire for the hazard production facility (nuclear power plant and others) the same as pilot cable, control cables, radio-frequency cables et al. In this paper, we investigate the specifics of the material selection of SCG with the express aim of hazardous man-made facility. We discuss the safe working conditions for cable glands. The research indicates the sintering powdered metals cables provide the reliability growth due to their properties. A number of studies have demonstrated the verification of material selection. On the face of it, we make findings indicating that double glazed sealed units could enhance reliability. We had evaluated sample reliability under fire conditions, seismic load, and pressure containment failure. We used the samples mineral insulated thermocouple cable.

  17. Test-retest reliability of Antonovsky's 13-item sense of coherence scale in patients with hand-related disorders

    DEFF Research Database (Denmark)

    Hansen, Alice Ørts; Kristensen, Hanne Kaae; Cederlund, Ragnhild

    2017-01-01

    to be a powerful tool to measure the ICF component personal factors, which could have an impact on patients' rehabilitation outcomes. Implications for rehabilitation Antonovsky's SOC-13 scale showed test-retest reliability for patients with hand-related disorders. The SOC-13 scale could be a suitable tool to help...... measure personal factors....

  18. Reliable computer systems.

    Science.gov (United States)

    Wear, L L; Pinkert, J R

    1993-11-01

    In this article, we looked at some decisions that apply to the design of reliable computer systems. We began with a discussion of several terms such as testability, then described some systems that call for highly reliable hardware and software. The article concluded with a discussion of methods that can be used to achieve higher reliability in computer systems. Reliability and fault tolerance in computers probably will continue to grow in importance. As more and more systems are computerized, people will want assurances about the reliability of these systems, and their ability to work properly even when sub-systems fail.

  19. Is Africa’s current growth reducing inequality? Evidence from some selected african countries

    Directory of Open Access Journals (Sweden)

    Alege P.O.

    2015-06-01

    Full Text Available Is Africa’s current growth reducing inequality? What are the implications of growth on output performances in Africa? Does the effect of Africa’s growth on sectorial output have any implication for inequality in Africa? The study investigates the effect of shocks on a set of macroeconomic variables on inequality (measured by life expectancy and the implication of this on sectors that are perceived to provide economic empowerment in form of employment for people living in the African countries in our sample. Studies already find that growth in many African countries has not been accompanied with significant improvement in employment. Therefore inequality is subject to a counter cyclical trend in production levels when export destination countries experience a recession. The study also provides insight on the effect of growth on sectorial output for three major sectors in the African economy with the intent of analyzing the impact of growth on sectorial development. The method used in this study is Panel Vector Autoregressive (PVAR estimation and the obvious advantage of this method lies in the fact that it allows us to capture both static and dynamic interdependencies and to treat the links across units in an unrestricted fashion. Data is obtained from World Bank (WDI Statistics for the period 1985 to 2012 (28 years for 10 African Countries. Our main findings confirm strong negative relationship between GDP growth and life expectancy and also for GDP and the services and manufacturing sector considering the full sample.

  20. Perinatal programming of childhood asthma: early fetal size, growth trajectory during infancy, and childhood asthma outcomes.

    Science.gov (United States)

    Turner, Steve

    2012-01-01

    The "fetal origins hypothesis" or concept of "developmental programming" suggests that faltering fetal growth and subsequent catch-up growth are implicated in the aetiology of cardiovascular disease. Associations between reduced birth weight, rapid postnatal weight gain, and asthma suggest that there are fetal origins to respiratory disease. The present paper first summarises the literature relating birth weight and post natal growth trajectories to asthma outcomes. Second, issues regarding the interpretation of antenatal fetal ultrasound measurements are discussed. Finally, recent reports linking antenatal measurement and growth trajectory to early childhood asthma outcomes are discussed. Understanding the nature and timing of factors which influence antenatal growth may give important insight into the antecedents of early-onset asthma with implications for interventions.

  1. 78 FR 41339 - Electric Reliability Organization Proposal To Retire Requirements in Reliability Standards

    Science.gov (United States)

    2013-07-10

    ...] Electric Reliability Organization Proposal To Retire Requirements in Reliability Standards AGENCY: Federal... Reliability Standards identified by the North American Electric Reliability Corporation (NERC), the Commission-certified Electric Reliability Organization. FOR FURTHER INFORMATION CONTACT: Kevin Ryan (Legal Information...

  2. Insulin-like growth factors: assay methods and their implications

    International Nuclear Information System (INIS)

    Guyda, H.J.; Posner, B.I.; Schiffrin, A.; Rappaport, R.; Postel-Vinay, M.C.; Corvol, M.T.

    1981-01-01

    The insulin-like growth factors (IGF's) are small molecular weight peptides (6-10 x 10 3 daltons) that circulate in blood plasma almost entirely bound to macromolecular carrier proteins. The growth-promoting and insulin-like activities of IGF's can be explained by the observed ability of these peptides to interact with the IGF receptor on the one hand and with the insulin receptor on the other. These observations have led to the establishment of radioreceptor assays (RRA's), competitive protein binding assays (CPBA's), and more recently radioimmunoassays (RIA's) for the IGF's that have different specificities. Because of their ease of performance and sensitivity, the radioligand assays have largely supplanted the biological assays originally utilized to identify and characterize these anabolic peptides. In this report the authors' studies are summarised which utilize a slightly acidic IGF which has been purified on the basis of its insulin-like activity in an insulin RRA and which was termed ILAs. They refer to purified insulin-like peptides that have the properties of a somatomedin by the generic term insulin-like growth factor (IGF). Somatomedin (SM) activity will be utilized to connote that activity in plasma or serum determined by bioassay. The competitive dose-response curves for IGF peptides in the insulin RRA as well as those in the ILAs RRA are presented. A combination of bioassays, RRA and RIA were employed to assess somatomedin activity and IGF peptide levels in a number of clinical circumstances. The correlations are discussed. (Auth.)

  3. 76 FR 58101 - Electric Reliability Organization Interpretation of Transmission Operations Reliability Standard

    Science.gov (United States)

    2011-09-20

    ....C. Cir. 2009). \\4\\ Mandatory Reliability Standards for the Bulk-Power System, Order No. 693, FERC... for maintaining real and reactive power balance. \\14\\ Electric Reliability Organization Interpretation...; Order No. 753] Electric Reliability Organization Interpretation of Transmission Operations Reliability...

  4. 76 FR 42534 - Mandatory Reliability Standards for Interconnection Reliability Operating Limits; System...

    Science.gov (United States)

    2011-07-19

    ... Reliability Operating Limits; System Restoration Reliability Standards AGENCY: Federal Energy Regulatory... data necessary to analyze and monitor Interconnection Reliability Operating Limits (IROL) within its... Interconnection Reliability Operating Limits, Order No. 748, 134 FERC ] 61,213 (2011). \\2\\ The term ``Wide-Area...

  5. 76 FR 66055 - North American Electric Reliability Corporation; Order Approving Interpretation of Reliability...

    Science.gov (United States)

    2011-10-25

    ...\\ Mandatory Reliability Standards for the Bulk-Power System, Order No. 693, FERC Stats. & Regs. ] 31,242... materially affected'' by Bulk-Power System reliability may request an interpretation of a Reliability... Electric Reliability Corporation; Order Approving Interpretation of Reliability Standard; Before...

  6. Modelling and estimating degradation processes with application in structural reliability

    International Nuclear Information System (INIS)

    Chiquet, J.

    2007-06-01

    The characteristic level of degradation of a given structure is modeled through a stochastic process called the degradation process. The random evolution of the degradation process is governed by a differential system with Markovian environment. We put the associated reliability framework by considering the failure of the structure once the degradation process reaches a critical threshold. A closed form solution of the reliability function is obtained thanks to Markov renewal theory. Then, we build an estimation methodology for the parameters of the stochastic processes involved. The estimation methods and the theoretical results, as well as the associated numerical algorithms, are validated on simulated data sets. Our method is applied to the modelling of a real degradation mechanism, known as crack growth, for which an experimental data set is considered. (authors)

  7. Alternative ceramic circuit constructions for low cost, high reliability applications

    International Nuclear Information System (INIS)

    Modes, Ch.; O'Neil, M.

    1997-01-01

    The growth in the use of hybrid circuit technology has recently been challenged by recent advances in low cost laminate technology, as well as the continued integration of functions into IC's. Size reduction of hybrid 'packages' has turned out to be a means to extend the useful life of this technology. The suppliers of thick film materials technology have responded to this challenge by developing a number of technology options to reduce circuit size, increase density, and reduce overall cost, while maintaining or increasing reliability. This paper provides an overview of the processes that have been developed, and, in many cases are used widely to produce low cost, reliable microcircuits. Comparisons of each of these circuit fabrication processes are made with a discussion of advantages and disadvantages of each technology. (author)

  8. Sustainable growth of the Kenyan dairy sector : a quick scan of robustness, reliability and resilience

    NARCIS (Netherlands)

    Rademaker, Corné J.; Omedo Bebe, Bockline; Lee, van der Jan; Kilelu, Catherine; Tonui, Charles

    2016-01-01

    This report provides an overview of how the Kenyan dairy sector performs in three analytical domains: the robustness of the supply chains, the reliability of institutional governance and the resilience of the innovation system. Analysis is by literature review, stakeholder interviews and a

  9. Inter-cohort growth for three tropical resources: tilapia, octopus and lobster

    OpenAIRE

    Iván Velázquez-Abunader; Victor Manuel Gómez-Muñoz; Silvia Salas; Javier M. J. Ruiz-Velazco

    2015-01-01

    Growth parameters are an important component for the stock assessment of exploited aquatic species. However, it is often difficult to apply direct methods to estimate growth and to analyse the differences between males and females, particularly in tropical areas. The objective of this study was to analyse the inter-cohort growth of three tropical resources and discuss the possible fisheries management implications. A simple method was used to compare individual growth curves obtained from len...

  10. Angiogenesis is not impaired in connective tissue growth factor (CTGF) knock-out mice

    NARCIS (Netherlands)

    Kuiper, Esther J.; Roestenberg, Peggy; Ehlken, Christoph; Lambert, Vincent; van Treslong-de Groot, Henny Bloys; Lyons, Karen M.; Agostini, Hans-Jürgen T.; Rakic, Jean-Marie; Klaassen, Ingeborg; van Noorden, Cornelis J. F.; Goldschmeding, Roel; Schlingemann, Reinier O.

    2007-01-01

    Connective tissue growth factor (CTGF) is a member of the CCN family of growth factors. CTGF is important in scarring, wound healing, and fibrosis. It has also been implicated to play a role in angiogenesis, in addition to vascular endothelial growth factor (VEGF). In the eye, angiogenesis and

  11. Reliability prediction for structures under cyclic loads and recurring inspections

    Directory of Open Access Journals (Sweden)

    Alberto W. S. Mello Jr

    2009-06-01

    Full Text Available This work presents a methodology for determining the reliability of fracture control plans for structures subjected to cyclic loads. It considers the variability of the parameters involved in the problem, such as initial flaw and crack growth curve. The probability of detection (POD curve of the field non-destructive inspection method and the condition/environment are used as important factors for structural confidence. According to classical damage tolerance analysis (DTA, inspection intervals are based on detectable crack size and crack growth rate. However, all variables have uncertainties, which makes the final result totally stochastic. The material properties, flight loads, engineering tools and even the reliability of inspection methods are subject to uncertainties which can affect significantly the final maintenance schedule. The present methodology incorporates all the uncertainties in a simulation process, such as Monte Carlo, and establishes a relationship between the reliability of the overall maintenance program and the proposed inspection interval, forming a “cascade” chart. Due to the scatter, it also defines the confidence level of the “acceptable” risk. As an example, the damage tolerance analysis (DTA results are presented for the upper cockpit longeron splice bolt of the BAF upgraded F-5EM. In this case, two possibilities of inspection intervals were found: one that can be characterized as remote risk, with a probability of failure (integrity nonsuccess of 1 in 10 million, per flight hour; and other as extremely improbable, with a probability of nonsuccess of 1 in 1 billion, per flight hour, according to aviation standards. These two results are compared with the classical military airplane damage tolerance requirements.

  12. Reliability methods in nuclear power plant ageing management

    International Nuclear Information System (INIS)

    Simola, K.

    1999-01-01

    The aim of nuclear power plant ageing management is to maintain an adequate safety level throughout the lifetime of the plant. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time-dependent degradation. The phases of ageing analyses are generally the identification of critical components, identification and evaluation of ageing effects, and development of mitigation methods. This thesis focuses on the use of reliability methods and analyses of plant- specific operating experience in nuclear power plant ageing studies. The presented applications and method development have been related to nuclear power plants, but many of the approaches can also be applied outside the nuclear industry. The thesis consists of a summary and seven publications. The summary provides an overview of ageing management and discusses the role of reliability methods in ageing analyses. In the publications, practical applications and method development are described in more detail. The application areas at component and system level are motor-operated valves and protection automation systems, for which experience-based ageing analyses have been demonstrated. Furthermore, Bayesian ageing models for repairable components have been developed, and the management of ageing by improving maintenance practices is discussed. Recommendations for improvement of plant information management in order to facilitate ageing analyses are also given. The evaluation and mitigation of ageing effects on structural components is addressed by promoting the use of probabilistic modelling of crack growth, and developing models for evaluation of the reliability of inspection results. (orig.)

  13. Reliability methods in nuclear power plant ageing management

    Energy Technology Data Exchange (ETDEWEB)

    Simola, K. [VTT Automation, Espoo (Finland). Industrial Automation

    1999-07-01

    The aim of nuclear power plant ageing management is to maintain an adequate safety level throughout the lifetime of the plant. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time-dependent degradation. The phases of ageing analyses are generally the identification of critical components, identification and evaluation of ageing effects, and development of mitigation methods. This thesis focuses on the use of reliability methods and analyses of plant- specific operating experience in nuclear power plant ageing studies. The presented applications and method development have been related to nuclear power plants, but many of the approaches can also be applied outside the nuclear industry. The thesis consists of a summary and seven publications. The summary provides an overview of ageing management and discusses the role of reliability methods in ageing analyses. In the publications, practical applications and method development are described in more detail. The application areas at component and system level are motor-operated valves and protection automation systems, for which experience-based ageing analyses have been demonstrated. Furthermore, Bayesian ageing models for repairable components have been developed, and the management of ageing by improving maintenance practices is discussed. Recommendations for improvement of plant information management in order to facilitate ageing analyses are also given. The evaluation and mitigation of ageing effects on structural components is addressed by promoting the use of probabilistic modelling of crack growth, and developing models for evaluation of the reliability of inspection results. (orig.)

  14. Standardization, Validity and Reliability Study of Gülhane Aphasia Test-2 (GAT-2

    Directory of Open Access Journals (Sweden)

    İlknur Maviş

    2007-04-01

    Full Text Available OBJECTIVE: Gülhane Aphasia Test-2 (GAT-2 has been developed to show the presence of a language disorder ‘aphasia’ and to give the clinician implications for the accompanying speech disorders such as apraxia and dysarthria. OBJECTIVE: The aim of the study was to report standardization, validity and reliability study of GAT-2. METHODS: : 10 healthy individuals were tested initially for the pilot study. 134 healthy individual was included to the standardization study and 30 individuals with aphasia and 11 individuals with right brain injury was included to the validation study. The inter group GAT-2 score differentiations and the effects of age, years of education, sex variances were observed. GAT-2 cut-off scores were calculated by the scores of healthy individuals. GAT-2 test-retest reliability and inter-observer reliability was calculated. RESULTS: Healthy individuals’ GAT-2 scores were significantly different from the GAT-2 scores of aphasic patients, but not from right brain injured patients’. Healthy individuals’ GAT-2 scores were not affected from the sex, age variances but from years of education, so cut-off scores were calculated by this variance. GAT-2 scores of aphasic patients were not affected from age, sex and years of education. Test-retest and inter-observer reliability and internal consistency results showed that GAT-2 is a highly reliable aphasia screening test. CONCLUSION: GAT-2 was found to be a standardized, highly reliable and a valid aphasia test for Turkish stroke patients with aphasia

  15. Innovation Geography and Regional Growth in European Union

    Directory of Open Access Journals (Sweden)

    George M. Korres

    2011-06-01

    Full Text Available There is a huge literature regarding the main determinants and sources of economic growth. Most of the recent work emphasizes on the role of knowledge and innovation activities typically produced by a specific sector of the economy, and on analyzing the implications and the importance for economic growth. Moreover, the socioeconomic and public policies aim to distinguish the determining factors of growth to enhance the regional cohesion and the convergence process. Much of the recent work on regional growth can be viewed as refining the basic economic insights of economic geography. This article attempts to analyze the European systems of innovation and the effects of European technological policy to regional growth.

  16. Inverse Reliability Task: Artificial Neural Networks and Reliability-Based Optimization Approaches

    OpenAIRE

    Lehký , David; Slowik , Ondřej; Novák , Drahomír

    2014-01-01

    Part 7: Genetic Algorithms; International audience; The paper presents two alternative approaches to solve inverse reliability task – to determine the design parameters to achieve desired target reliabilities. The first approach is based on utilization of artificial neural networks and small-sample simulation Latin hypercube sampling. The second approach considers inverse reliability task as reliability-based optimization task using double-loop method and also small-sample simulation. Efficie...

  17. Reliability and Validity of a Spanish Version of the Posttraumatic Growth Inventory

    Science.gov (United States)

    Weiss, Tzipi; Berger, Roni

    2006-01-01

    Objectives. This study was designed to adapt and validate a Spanish translation of the Posttraumatic Growth Inventory (PTGI) for the assessment of positive life changes following the stressful experiences of immigration. Method. A cross-cultural equivalence model was used to pursue semantic, content, conceptual, and technical equivalence.…

  18. 76 FR 23801 - North American Electric Reliability Corporation; Order Approving Reliability Standard

    Science.gov (United States)

    2011-04-28

    ... have an operating plan and facilities for backup functionality to ensure Bulk-Power System reliability... entity's primary control center on the reliability of the Bulk-Power System. \\1\\ Mandatory Reliability... potential impact of a violation of the Requirement on the reliability of the Bulk-Power System. The...

  19. Suncor maintenance and reliability

    Energy Technology Data Exchange (ETDEWEB)

    Little, S. [Suncor Energy, Calgary, AB (Canada)

    2006-07-01

    Fleet maintenance and reliability at Suncor Energy was discussed in this presentation, with reference to Suncor Energy's primary and support equipment fleets. This paper also discussed Suncor Energy's maintenance and reliability standard involving people, processes and technology. An organizational maturity chart that graphed organizational learning against organizational performance was illustrated. The presentation also reviewed the maintenance and reliability framework; maintenance reliability model; the process overview of the maintenance and reliability standard; a process flow chart of maintenance strategies and programs; and an asset reliability improvement process flow chart. An example of an improvement initiative was included, with reference to a shovel reliability review; a dipper trip reliability investigation; bucket related failures by type and frequency; root cause analysis of the reliability process; and additional actions taken. Last, the presentation provided a graph of the results of the improvement initiative and presented the key lessons learned. tabs., figs.

  20. Reliability and maintainability assessment factors for reliable fault-tolerant systems

    Science.gov (United States)

    Bavuso, S. J.

    1984-01-01

    A long term goal of the NASA Langley Research Center is the development of a reliability assessment methodology of sufficient power to enable the credible comparison of the stochastic attributes of one ultrareliable system design against others. This methodology, developed over a 10 year period, is a combined analytic and simulative technique. An analytic component is the Computer Aided Reliability Estimation capability, third generation, or simply CARE III. A simulative component is the Gate Logic Software Simulator capability, or GLOSS. The numerous factors that potentially have a degrading effect on system reliability and the ways in which these factors that are peculiar to highly reliable fault tolerant systems are accounted for in credible reliability assessments. Also presented are the modeling difficulties that result from their inclusion and the ways in which CARE III and GLOSS mitigate the intractability of the heretofore unworkable mathematics.

  1. Validity and reliability of acoustic analysis of respiratory sounds in infants

    Science.gov (United States)

    Elphick, H; Lancaster, G; Solis, A; Majumdar, A; Gupta, R; Smyth, R

    2004-01-01

    Objective: To investigate the validity and reliability of computerised acoustic analysis in the detection of abnormal respiratory noises in infants. Methods: Blinded, prospective comparison of acoustic analysis with stethoscope examination. Validity and reliability of acoustic analysis were assessed by calculating the degree of observer agreement using the κ statistic with 95% confidence intervals (CI). Results: 102 infants under 18 months were recruited. Convergent validity for agreement between stethoscope examination and acoustic analysis was poor for wheeze (κ = 0.07 (95% CI, –0.13 to 0.26)) and rattles (κ = 0.11 (–0.05 to 0.27)) and fair for crackles (κ = 0.36 (0.18 to 0.54)). Both the stethoscope and acoustic analysis distinguished well between sounds (discriminant validity). Agreement between observers for the presence of wheeze was poor for both stethoscope examination and acoustic analysis. Agreement for rattles was moderate for the stethoscope but poor for acoustic analysis. Agreement for crackles was moderate using both techniques. Within-observer reliability for all sounds using acoustic analysis was moderate to good. Conclusions: The stethoscope is unreliable for assessing respiratory sounds in infants. This has important implications for its use as a diagnostic tool for lung disorders in infants, and confirms that it cannot be used as a gold standard. Because of the unreliability of the stethoscope, the validity of acoustic analysis could not be demonstrated, although it could discriminate between sounds well and showed good within-observer reliability. For acoustic analysis, targeted training and the development of computerised pattern recognition systems may improve reliability so that it can be used in clinical practice. PMID:15499065

  2. Growth-supporting activity for Legionella pneumophila in tap water cultures and implication of hartmannellid amoebae as growth factors.

    Science.gov (United States)

    Wadowsky, R M; Butler, L J; Cook, M K; Verma, S M; Paul, M A; Fields, B S; Keleti, G; Sykora, J L; Yee, R B

    1988-11-01

    Photosynthetic cyanobacteria, heterotrophic bacteria, free-living amoebae, and ciliated protozoa may support growth of Legionella pneumophila. Studies were done with two tap water cultures (WS1 and WS2) containing L. pneumophila and associated microbiota to characterize growth-supporting activity and assess the relative importance of the microbiota in supporting multiplication of L. pneumophila. The water cultures were incubated in the dark at 35 degrees C. The growth-supporting factor(s) was separated from each culture by filtration through 1-micron-pore-size membrane filters. The retentate was then suspended in sterile tap water. Multiplication of L. pneumophila occurred when both the retentate suspension and the filtrate from either culture were inoculated into sterile tap water. L. pneumophila did not multiply in tap water inoculated with only the filtrate, even though filtration did not reduce the concentration of L. pneumophila or heterotrophic bacteria in either culture. Growth-supporting activity of the retentate suspension from WS1 was inactivated at 60 degrees C but unaffected at 0, 25, and 45 degrees C after 30-min incubations. Filtration experiments indicated that the growth-supporting factor(s) in WS1 was 2 to 5 micron in diameter. Ciliated protozoa were not detected in either culture. Hartmannellid amoebae were conclusively demonstrated in WS2 but not in WS1. L. pneumophila multiplied in tap water inoculated with the amoebae (10(3)/ml) and the 1-micron filtrate of WS2. No multiplication occurred in tap water inoculated with the filtrate only. Growth-supporting activity for L. pneumophila may be present in plumbing systems; hartmannellid amoebae appear to be important determinants of multiplication of L. pneumophila in some tap water cultures.

  3. Power Electronic Packaging Design, Assembly Process, Reliability and Modeling

    CERN Document Server

    Liu, Yong

    2012-01-01

    Power Electronic Packaging presents an in-depth overview of power electronic packaging design, assembly,reliability and modeling. Since there is a drastic difference between IC fabrication and power electronic packaging, the book systematically introduces typical power electronic packaging design, assembly, reliability and failure analysis and material selection so readers can clearly understand each task's unique characteristics. Power electronic packaging is one of the fastest growing segments in the power electronic industry, due to the rapid growth of power integrated circuit (IC) fabrication, especially for applications like portable, consumer, home, computing and automotive electronics. This book also covers how advances in both semiconductor content and power advanced package design have helped cause advances in power device capability in recent years. The author extrapolates the most recent trends in the book's areas of focus to highlight where further improvement in materials and techniques can d...

  4. FDI in Tourism Sector and Economic Growth in Sumatra Utara

    Directory of Open Access Journals (Sweden)

    Parhimpunan Simatupang

    2014-09-01

    Full Text Available Globalization and neo liberal policies such as liberalization and privatization have generated a significant growth for FDI and considered an important source for capital and foreign currency, capable of spurring economic growth in developing countries. One sector that received particular attention, due to its significant contributions towards economic development, especially in Indonesia, is tourism. Tourism investments in Indonesia are mainly focused on the development of fully-integrated resort sites that help boost the construction of tourist facilities such as hotels and the development of the surrounding environment through social and cultural aspects. The total contribution of travel and tourism to GDP was IDR736.3 billion or 8.9% of GDP in 2012. Foreign direct tourism investments grew by 210% between 2011 and 2012, or at an annual compound average growth rate of 38% between 2006 and 2012. While the implications are at national level, not much could be gathered on the local perspectives. This paper intends to explore the implication of FDI in tourism sector towards economic growth in one of tourism attraction provinces in Indonesia—Sumatra Utara. Specifically, which economic factors contributed towards FDI inflows and their impacts on economic growth in Sumatra Utara.

  5. When growth and photosynthesis don't match: implications for carbon balance models

    Science.gov (United States)

    Medlyn, B.; Mahmud, K.; Duursma, R.; Pfautsch, S.; Campany, C.

    2017-12-01

    Most models of terrestrial plant growth are based on the principle of carbon balance: that growth can be predicted from net uptake of carbon via photosynthesis. A key criticism leveled at these models by plant physiologists is that there are many circumstances in which plant growth appears to be independent of photosynthesis: for example, during the onset of drought, or with rising atmospheric CO2 concentration. A crucial problem for terrestrial carbon cycle models is to develop better representations of plant carbon balance when there is a mismatch between growth and photosynthesis. Here we present two studies providing insight into this mismatch. In the first, effects of root restriction on plant growth were examined by comparing Eucalyptus tereticornis seedlings growing in containers of varying sizes with freely-rooted seedlings. Root restriction caused a reduction in photosynthesis, but this reduction was insufficient to explain the even larger reduction observed in growth. We applied data assimilation to a simple carbon balance model to quantify the response of carbon balance as a whole in this experiment. We inferred that, in addition to photosynthesis, there are significant effects of root restriction on growth respiration, carbon allocation, and carbohydrate utilization. The second study was carried out at the EucFACE Free-Air CO2 Enrichment experiment. At this experiment, photosynthesis of the overstorey trees is increased with enriched CO2, but there is no significant effect on above-ground productivity. These mature trees have reached their maximum height but are at significant risk of canopy loss through disturbance, and we hypothesized that additional carbon taken up through photosynthesis is preferentially allocated to storage rather than growth. We tested this hypothesis by measuring stemwood non-structural carbohydrates (NSC) during a psyllid outbreak that completely defoliated the canopy in 2015. There was a significant drawdown of NSC during

  6. The implications of automation for economic growth and the labor share of income

    OpenAIRE

    Prettner, Klaus

    2016-01-01

    We introduce automation into the standard Solovian model of capital accumulation and show that (i) there is the possibility of perpetual growth, even in the absence of technological progress; (ii) the long-run economic growth rate declines with population growth, which is consistent with the available empirical evidence; (iii) there is a unique share of savings diverted to automation that maximizes the long-run growth rate of the economy; (iv) the labor share declines with automation to an ex...

  7. [Associated factors in newborns with intrauterine growth retardation].

    Science.gov (United States)

    Thompson-Chagoyán, Oscar C; Vega-Franco, Leopoldo

    2008-01-01

    To identify the risk factors implicated in the intrauterine growth retardation (IUGR) of neonates born in a social security institution. Case controls design study in 376 neonates: 188 with IUGR (weight RCIU in the population.

  8. Growth Conditions Regulate the Requirements for Caulobacter Chromosome Segregation

    DEFF Research Database (Denmark)

    Shebelut, Conrad W.; Jensen, Rasmus Bugge; Gitai, Zemer

    2009-01-01

    Growth environments are important metabolic and developmental regulators. Here we demonstrate a growth environment-dependent effect on Caulobacter chromosome segregation of a small-molecule inhibitor of the MreB bacterial actin cytoskeleton. Our results also implicate ParAB as important segregation...... determinants, suggesting that multiple distinct mechanisms can mediate Caulobacter chromosome segregation and that their relative contributions can be environmentally regulated....

  9. Reliability training

    Science.gov (United States)

    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.

  10. Perinatal Programming of Childhood Asthma: Early Fetal Size, Growth Trajectory during Infancy, and Childhood Asthma Outcomes

    Directory of Open Access Journals (Sweden)

    Steve Turner

    2012-01-01

    Full Text Available The “fetal origins hypothesis” or concept of “developmental programming” suggests that faltering fetal growth and subsequent catch-up growth are implicated in the aetiology of cardiovascular disease. Associations between reduced birth weight, rapid postnatal weight gain, and asthma suggest that there are fetal origins to respiratory disease. The present paper first summarises the literature relating birth weight and post natal growth trajectories to asthma outcomes. Second, issues regarding the interpretation of antenatal fetal ultrasound measurements are discussed. Finally, recent reports linking antenatal measurement and growth trajectory to early childhood asthma outcomes are discussed. Understanding the nature and timing of factors which influence antenatal growth may give important insight into the antecedents of early-onset asthma with implications for interventions.

  11. Reliability analysis of mining equipment: A case study of a crushing plant at Jajarm Bauxite Mine in Iran

    International Nuclear Information System (INIS)

    Barabady, Javad; Kumar, Uday

    2008-01-01

    The performance of mining machines depends on the reliability of the equipment used, the operating environment, the maintenance efficiency, the operation process, the technical expertise of the miners, etc. As the size and complexity of mining equipments continue to increase, the implications of equipment failure become ever more critical. Therefore, reliability analysis is required to identify the bottlenecks in the system and to find the components or subsystems with low reliability for a given designed performance. It is important to select a suitable method for data collection as well as for reliability analysis. This paper presents a case study describing reliability and availability analysis of the crushing plant number 3 at Jajarm Bauxite Mine in Iran. In this study, the crushing plant number 3 is divided into six subsystems. The parameters of some probability distributions, such as Weibull, Exponential, and Lognormal distributions have been estimated by using ReliaSoft's Weibull++6 software. The results of the analysis show that the conveyer subsystem and secondary screen subsystem are critical from a reliability point of view, and the secondary crusher subsystem and conveyer subsystem are critical from an availability point of view. The study also shows that the reliability analysis is very useful for deciding maintenance intervals

  12. U.S. National Security Implications of Chinese Involvement in Latin America

    National Research Council Canada - National Science Library

    Ellis, R. E

    2005-01-01

    ... implications for the United States. Sustained Chinese economic growth requires ever greater quantities of basic commodities such as petroleum products, coal, iron and steel, and strategic minerals...

  13. Statistical implications of adjustments of raw ILI (In-Line Inspection) data

    Energy Technology Data Exchange (ETDEWEB)

    Timashev, Svyatoslav A.; Bushinskaya, Anna V. [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Ural Branch. Sciences and Engineering Center ' Reliability and Safety of Large Systems and Machines'

    2009-07-01

    The paper describes the implications and inferences that inevitably arise when deliberate 'adjustments' of raw MFL ILI data are made when delivering the final report on conducted ILI and/or performing defect sizing and reliability assessments needed for pipeline integrity management plans (IMPs). The root causes of data adjustments are discussed, main types of adjustments are classified and the consequences as related to pipeline residual life, reliability and safety are described. A comparison is performed between adjustment and the full statistical analysis (FSA), as applied to raw ILI and verification data. The consequences of defect data adjustment as related to pipeline reliability and POF and possible litigation issues are discussed. Case studies are presented which demonstrate the application of the FSA method to the results of ILI and verification measurements on pipelines that are located on three continents. Some assessments of the actual reliability of pipelines with defects are given. (author)

  14. 76 FR 16240 - Mandatory Reliability Standards for Interconnection Reliability Operating Limits

    Science.gov (United States)

    2011-03-23

    ... identified by the Commission. \\5\\ Mandatory Reliability Standards for the Bulk-Power System, Order No. 693... reliability of the interconnection by ensuring that the bulk electric system is assessed during the operations... responsibility for SOLs. Further, Bulk-Power System reliability practices assign responsibilities for analyzing...

  15. The Reliability and Predictive Validity of the Stalking Risk Profile.

    Science.gov (United States)

    McEwan, Troy E; Shea, Daniel E; Daffern, Michael; MacKenzie, Rachel D; Ogloff, James R P; Mullen, Paul E

    2018-03-01

    This study assessed the reliability and validity of the Stalking Risk Profile (SRP), a structured measure for assessing stalking risks. The SRP was administered at the point of assessment or retrospectively from file review for 241 adult stalkers (91% male) referred to a community-based forensic mental health service. Interrater reliability was high for stalker type, and moderate-to-substantial for risk judgments and domain scores. Evidence for predictive validity and discrimination between stalking recidivists and nonrecidivists for risk judgments depended on follow-up duration. Discrimination was moderate (area under the curve = 0.66-0.68) and positive and negative predictive values good over the full follow-up period ( Mdn = 170.43 weeks). At 6 months, discrimination was better than chance only for judgments related to stalking of new victims (area under the curve = 0.75); however, high-risk stalkers still reoffended against their original victim(s) 2 to 4 times as often as low-risk stalkers. Implications for the clinical utility and refinement of the SRP are discussed.

  16. Diatom production in the marine environment : implications for larval fish growth and condition

    DEFF Research Database (Denmark)

    St. John, Michael; Clemmesen, C.; Lund, T.

    2001-01-01

    To test the effects of diatom production on larval fish growth and condition. laboratory experiments were performed with larval North Sea cod reared on different algal food chains. These food chains were based on cultures of (a) the diatoms Skeletonema costatum and Thalassiosira weissflogii: (b....../omega6 fatty acids in the algal source had no significant effect. The highest and lowest growth rates were observed in food chains based on H. triquetra and T. weissflogii. respectively (means for days 14-16 of 4.0 and - 4.7). The mixed diatom/dinoflagellate diet resulted in inter- mediate growth rates...... and condition. Regressions of growth rates against EPA and DHA content indicated no inhibitory effect of diatom production on growth in larval cod...

  17. China’s Rise and Its Implications for the Global Economy

    Directory of Open Access Journals (Sweden)

    Jitaru Loredana

    2017-01-01

    Full Text Available Since 1978, the world has been witnessing China’s formidable growth at an average growthyearly rate of about 10%. Even when the world economy was affected by the global economicfinancialcrisis, China’s economy grew 9-10% per year. The objective of this study is to provide acomplex view of the Chinese economic growth and to identify the effects of this growth on theworld economy. To that effect, this paper is structured in two parts. In the first part, we analysedthe evolution of the Chinese economic growth and the drivers of this spectacular growth. In thesecond part, we identified and analysed the implications of this growth for the global economy. Toachieve our objective, we used the method of documentary research.

  18. Design for reliability: NASA reliability preferred practices for design and test

    Science.gov (United States)

    Lalli, Vincent R.

    1994-01-01

    This tutorial summarizes reliability experience from both NASA and industry and reflects engineering practices that support current and future civil space programs. These practices were collected from various NASA field centers and were reviewed by a committee of senior technical representatives from the participating centers (members are listed at the end). The material for this tutorial was taken from the publication issued by the NASA Reliability and Maintainability Steering Committee (NASA Reliability Preferred Practices for Design and Test. NASA TM-4322, 1991). Reliability must be an integral part of the systems engineering process. Although both disciplines must be weighed equally with other technical and programmatic demands, the application of sound reliability principles will be the key to the effectiveness and affordability of America's space program. Our space programs have shown that reliability efforts must focus on the design characteristics that affect the frequency of failure. Herein, we emphasize that these identified design characteristics must be controlled by applying conservative engineering principles.

  19. Reliability models for a nonrepairable system with heterogeneous components having a phase-type time-to-failure distribution

    International Nuclear Information System (INIS)

    Kim, Heungseob; Kim, Pansoo

    2017-01-01

    This research paper presents practical stochastic models for designing and analyzing the time-dependent reliability of nonrepairable systems. The models are formulated for nonrepairable systems with heterogeneous components having phase-type time-to-failure distributions by a structured continuous time Markov chain (CTMC). The versatility of the phase-type distributions enhances the flexibility and practicality of the systems. By virtue of these benefits, studies in reliability engineering can be more advanced than the previous studies. This study attempts to solve a redundancy allocation problem (RAP) by using these new models. The implications of mixing components, redundancy levels, and redundancy strategies are simultaneously considered to maximize the reliability of a system. An imperfect switching case in a standby redundant system is also considered. Furthermore, the experimental results for a well-known RAP benchmark problem are presented to demonstrate the approximating error of the previous reliability function for a standby redundant system and the usefulness of the current research. - Highlights: • Phase-type time-to-failure distribution is used for components. • Reliability model for nonrepairable system is developed using Markov chain. • System is composed of heterogeneous components. • Model provides the real value of standby system reliability not an approximation. • Redundancy allocation problem is used to show usefulness of this model.

  20. Prediction of safety critical software operational reliability from test reliability using testing environment factors

    International Nuclear Information System (INIS)

    Jung, Hoan Sung; Seong, Poong Hyun

    1999-01-01

    It has been a critical issue to predict the safety critical software reliability in nuclear engineering area. For many years, many researches have focused on the quantification of software reliability and there have been many models developed to quantify software reliability. Most software reliability models estimate the reliability with the failure data collected during the test assuming that the test environments well represent the operation profile. User's interest is however on the operational reliability rather than on the test reliability. The experiences show that the operational reliability is higher than the test reliability. With the assumption that the difference in reliability results from the change of environment, from testing to operation, testing environment factors comprising the aging factor and the coverage factor are developed in this paper and used to predict the ultimate operational reliability with the failure data in testing phase. It is by incorporating test environments applied beyond the operational profile into testing environment factors. The application results show that the proposed method can estimate the operational reliability accurately. (Author). 14 refs., 1 tab., 1 fig

  1. Power electronics reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Trade-offs in size, quantity and reliability of generalized nuclear power plants

    International Nuclear Information System (INIS)

    Hill, D.; Mubayi, V.

    1987-01-01

    In the 1960's and 1970's, there was rapid growth in the size of newly started nuclear power plants because of the anticipated advantages of increasing scale. Any such advantages were overwhelmed by the complications that arose with long construction times, and attention is now being given to a ''second generation'' of smaller plants of new design. Providing the same production capacity will require larger numbers of plants if they are smaller. Although it seems to have received little attention previously, there should be compensating economies due to ''learning curve'' effects in the manufacture of multiple units of standardized designs (Hill 1983). Moreover, the use of a large number of smaller units increases the overall system reliability. On balance, however, it is not clear how scale, quantity, and reliability considerations interact to determine optimal plant size. The purpose of this paper is to begin examining the size-quantity tradeoff taking into account scale effects, the manufacturing learning curve, plant availability, and system reliability

  3. Reliability assessment of hydraulic cylinders considering service loads and flaw distribution

    International Nuclear Information System (INIS)

    Altamura, Alessandra; Beretta, Stefano

    2012-01-01

    Manufacturing process, service conditions and material properties are all necessary requirements to a good design of tubular mechanical components subjected to fatigue. The most common approach to this design is usually deterministic, where a fixed NDT threshold, related to flaw acceptance limit, is set. However many uncertainties are left aside, i.e. the failure probability related to the fatigue strength under applied loads. This paper addresses the reliability evaluation of tubular mechanical components carrying some flaws and subjected to cyclic internal pressure variation. The aim is comparing the probability of failure obtained under several assumptions. A reliability assessment model, based on a random variable approach, has been implemented by using the Monte Carlo method. The analysis of the results, from a case study based on load spectra measurements of hydraulic cylinders of earth moving machines, has consented to evaluate the most important factors influencing the fatigue life prediction of these components. Highlights: ► Reliability evaluation of tubular components subjected to variable internal pressure. ► The dispersion of the threshold controls the stochasticity of crack growth. ► A random variable model has been developed using Monte Carlo. ► Initial crack size and spectrum shape are key factors in reliability evaluation.

  4. The reliability process as an integral part of the product creation process. A contribution to assure the maturity level; Der Zuverlaessigkeitsprozess als integraler Bestandteil des Produktentstehungsprozesses. Ein Beitrag zur Reifegradabsicherung

    Energy Technology Data Exchange (ETDEWEB)

    Savic, R.; Kusenic, D. [ZF Friedrichshafen AG (Germany)

    2007-07-01

    The reliability process in the automotive and supplier industry covers all phases of the product creation process. The objective of the main tasks of the reliability process is to meet the requirements of the customer, authorities and law. Therefore the reliability process assures a high readiness for a stable and undisturbed start of production in the line with the product creation process. The paper presents a reliability based model to assure the maturity level in form of the reliability growth methodology and its verification respectively monitoring of the progress during the product creation process. As a consequence, the performance of the product creation process is required to be monitored and reported on. In this case the monitoring is based on the reliability parameters of the reliability growth in form of the achieved MTBF respectively MTTF, out of which the maturity level is derived during the product creation process. This makes it possible for the reliability management to track the reliability targets and the efficiency of corrective actions and the product creation process itself for all phases of the process. (orig.)

  5. Potential effects of plant growth promoting rhizobacteria ...

    African Journals Online (AJOL)

    Damping off caused by Sclerotium rolfsii on cowpea results in yield losses with serious socioeconomic implication. Induction of defense responses by plant growth promoting rhizobacteria (PGPR) is largely associated with the production of defense enzyme phenyl ammonia lyase (PAL) and oxidative enzymes like ...

  6. 76 FR 73608 - Reliability Technical Conference, North American Electric Reliability Corporation, Public Service...

    Science.gov (United States)

    2011-11-29

    ... or municipal authority play in forming your bulk power system reliability plans? b. Do you support..., North American Electric Reliability Corporation (NERC) Nick Akins, CEO of American Electric Power (AEP..., EL11-62-000] Reliability Technical Conference, North American Electric Reliability Corporation, Public...

  7. Reliability and validity of the de Morton Mobility Index in individuals with sub-acute stroke.

    Science.gov (United States)

    Braun, Tobias; Marks, Detlef; Thiel, Christian; Grüneberg, Christian

    2018-02-04

    To establish the validity and reliability of the de Morton Mobility Index (DEMMI) in patients with sub-acute stroke. This cross-sectional study was performed in a neurological rehabilitation hospital. We assessed unidimensionality, construct validity, internal consistency reliability, inter-rater reliability, minimal detectable change and possible floor and ceiling effects of the DEMMI in adult patients with sub-acute stroke. The study included a total sample of 121 patients with sub-acute stroke. We analysed validity (n = 109) and reliability (n = 51) in two sub-samples. Rasch analysis indicated unidimensionality with an overall fit to the model (chi-square = 12.37, p = 0.577). All hypotheses on construct validity were confirmed. Internal consistency reliability (Cronbach's alpha = 0.94) and inter-rater reliability (intraclass correlation coefficient = 0.95; 95% confidence interval: 0.92-0.97) were excellent. The minimal detectable change with 90% confidence was 13 points. No floor or ceiling effects were evident. These results indicate unidimensionality, sufficient internal consistency reliability, inter-rater reliability, and construct validity of the DEMMI in patients with a sub-acute stroke. Advantages of the DEMMI in clinical application are the short administration time, no need for special equipment and interval level data. The de Morton Mobility Index, therefore, may be a useful performance-based bedside test to measure mobility in individuals with a sub-acute stroke across the whole mobility spectrum. Implications for Rehabilitation The de Morton Mobility Index (DEMMI) is an unidimensional measurement instrument of mobility in individuals with sub-acute stroke. The DEMMI has excellent internal consistency and inter-rater reliability, and sufficient construct validity. The minimal detectable change of the DEMMI with 90% confidence in stroke rehabilitation is 13 points. The lack of any floor or ceiling effects on hospital admission indicates

  8. Animal spirits, competitive markets, and endogenous growth

    Science.gov (United States)

    Miyazaki, Kenji

    2013-10-01

    This paper uses a simple model with an endogenous discount rate and linear technology to investigate whether a competitive equilibrium has a higher balanced growth path (BGP) than the social planning solution and whether the BGP is determinate or indeterminate. The implications are as follows. To start with, people with an instinct to compare themselves with others possess an endogenous discount rate. In turn, this instinct affects the economic growth rate in a competitive market economy. The competitive market economy also sometimes achieves higher economic growth than a social planning economy. However, the outcomes of market economy occasionally fluctuate because of the presence of the self-fulfilling prophecy or animal spirits.

  9. Reliability-based assessment of deteriorating ship-shaped offshore structures

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Uraga, Efren

    2009-11-15

    components rises accordingly. Therefore, it is indispensable for FPSO operators to assess the safety of existing vessels with proper consideration of the uncertainties involved. The aim of this dissertation is to discuss the safety assessment of an existing shipshaped offshore structure subjected to deterioration, where the interaction among different deteriorating phenomena such as fatigue, corrosion and fracture, are explicitly accounted for in a systematic and consistent manner. The format of this thesis report consists of an extended summary intended to emphasize the main contributions achieved and the relevant issues dealt with during this research work, which resulted in the production of three articles that have already been published, annexed at the end of the report. The first article, referred to as Article 1 throughout this report, was published in the International Journal of Fatigue (2007). This article deals with the treatment of uncertainties related to the fatigue crack growth of surface cracks on plated connections and compares different reliability-based limit state formulations including a bi-linear crack growth law that is recommended by the British Standard BS-7910 (1999). Calibration of the bi-linear fracture mechanics formulation is performed with respect to design SN curves considering the parameters with largest uncertainties. The second article, Article 2, published in Reliability Engineering and System Safety (2008) describes a procedure based on reliability techniques to assess the safety level on a welded connection of an aging FPSO with respect fatigue failure, taking into account in the crack growth estimation the effect of the vessel being exposed to various climate conditions throughout the service life. This means that the fatigue damage accumulated under previous operational conditions of the vessel, e.g. as tanker before conversion, is explicitly accounted for in the failure function. Thus, the uncertainties are also explicitly considered

  10. Correlation of thermodynamics and grain growth kinetics in nanocrystalline metals

    International Nuclear Information System (INIS)

    Song Xiaoyan; Zhang Jiuxing; Li Lingmei; Yang Keyong; Liu Guoquan

    2006-01-01

    We investigated the correlation of thermodynamics and grain growth kinetics of nanocrystalline metals both theoretically and experimentally. A model was developed to describe the thermodynamic properties of nanograin boundaries, which could give reliable predictions in the destabilization characteristics of nanograin structures and the slowing down of grain growth kinetics at a constant temperature. Both the temperature-varying and isothermal nanograin growth behaviors in pure nanocrystalline Co were studied to verify the thermodynamic predictions. The experimental results showing that discontinuous nanograin growth takes place at a certain temperature and grain growth rate decreases monotonically with time confirm our thermodynamics-based description of nanograin growth characteristics. Therefore, we propose a thermodynamic viewpoint to explain the deviation of grain growth kinetics in nanocrystalline metals from those of polycrystalline materials

  11. Assessment of system reliability for a stochastic-flow distribution network with the spoilage property

    Science.gov (United States)

    Lin, Yi-Kuei; Huang, Cheng-Fu; Yeh, Cheng-Ta

    2016-04-01

    In supply chain management, satisfying customer demand is the most concerned for the manager. However, the goods may rot or be spoilt during delivery owing to natural disasters, inclement weather, traffic accidents, collisions, and so on, such that the intact goods may not meet market demand. This paper concentrates on a stochastic-flow distribution network (SFDN), in which a node denotes a supplier, a transfer station, or a market, while a route denotes a carrier providing the delivery service for a pair of nodes. The available capacity of the carrier is stochastic because the capacity may be partially reserved by other customers. The addressed problem is to evaluate the system reliability, the probability that the SFDN can satisfy the market demand with the spoilage rate under the budget constraint from multiple suppliers to the customer. An algorithm is developed in terms of minimal paths to evaluate the system reliability along with a numerical example to illustrate the solution procedure. A practical case of fruit distribution is presented accordingly to emphasise the management implication of the system reliability.

  12. Scoping study on trends in the economic value of electricity reliability to the U.S. economy

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph; Koomey, Jonathan; Lehman, Bryan; Martin, Nathan; Mills, Evan; Webber, Carrie; Worrell, Ernst

    2001-06-01

    During the past three years, working with more than 150 organizations representing public and private stakeholders, EPRI has developed the Electricity Technology Roadmap. The Roadmap identifies several major strategic challenges that must be successfully addressed to ensure a sustainable future in which electricity continues to play an important role in economic growth. Articulation of these anticipated trends and challenges requires a detailed understanding of the role and importance of reliable electricity in different sectors of the economy. This report is intended to contribute to that understanding by analyzing key aspects of trends in the economic value of electricity reliability in the U.S. economy. We first present a review of recent literature on electricity reliability costs. Next, we describe three distinct end-use approaches for tracking trends in reliability needs: (1) an analysis of the electricity-use requirements of office equipment in different commercial sectors; (2) an examination of the use of aggregate statistical indicators of industrial electricity use and economic activity to identify high reliability-requirement customer market segments; and (3) a case study of cleanrooms, which is a cross-cutting market segment known to have high reliability requirements. Finally, we present insurance industry perspectives on electricity reliability as an example of a financial tool for addressing customers' reliability needs.

  13. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  14. Design reliability engineering

    International Nuclear Information System (INIS)

    Buden, D.; Hunt, R.N.M.

    1989-01-01

    Improved design techniques are needed to achieve high reliability at minimum cost. This is especially true of space systems where lifetimes of many years without maintenance are needed and severe mass limitations exist. Reliability must be designed into these systems from the start. Techniques are now being explored to structure a formal design process that will be more complete and less expensive. The intent is to integrate the best features of design, reliability analysis, and expert systems to design highly reliable systems to meet stressing needs. Taken into account are the large uncertainties that exist in materials, design models, and fabrication techniques. Expert systems are a convenient method to integrate into the design process a complete definition of all elements that should be considered and an opportunity to integrate the design process with reliability, safety, test engineering, maintenance and operator training. 1 fig

  15. Case managers' experiences of personal growth: learning from consumers.

    Science.gov (United States)

    Stein, Catherine H; Craft, Scott A

    2007-04-01

    This study examines aspects of case managers' perceived personal growth in their work with consumers. Using a sample of 98 case managers, the psychometric properties of a brief self-report measure of personal growth of case managers were examined. The Case Manager Personal Growth Scale (CMPG) showed good reliability and construct validity as evidenced by negative correlations with scores on professional burnout and positive correlations with personal accomplishment and job satisfaction scores. CMPG scores were unrelated to social desirability scores or caseload size and positively related to age and tenure in the mental health system. Results suggest the strong relevance of the construct of personal growth for case managers.

  16. A fracture mechanics and reliability based method to assess non-destructive testings for pressure vessels

    International Nuclear Information System (INIS)

    Kitagawa, Hideo; Hisada, Toshiaki

    1979-01-01

    Quantitative evaluation has not been made on the effects of carrying out preservice and in-service nondestructive tests for securing the soundness, safety and maintainability of pressure vessels, spending large expenses and labor. Especially the problems concerning the time and interval of in-service inspections lack the reasonable, quantitative evaluation method. In this paper, the problems of pressure vessels are treated by having developed the analysis method based on reliability technology and probability theory. The growth of surface cracks in pressure vessels was estimated, using the results of previous studies. The effects of nondestructive inspection on the defects in pressure vessels were evaluated, and the influences of many factors, such as plate thickness, stress, the accuracy of inspection and so on, on the effects of inspection, and the method of evaluating the inspections at unequal intervals were investigated. The analysis of reliability taking in-service inspection into consideration, the evaluation of in-service inspection and other affecting factors through the typical examples of analysis, and the review concerning the time of inspection are described. The method of analyzing the reliability of pressure vessels, considering the growth of defects and preservice and in-service nondestructive tests, was able to be systematized so as to be practically usable. (Kako, I.)

  17. Factors implicated to radioresistance of breast cancer and their possible roles

    International Nuclear Information System (INIS)

    Yan Weili; Huang Gang

    2006-01-01

    Radiotherapy plays an important role in the management of breast cancer. The recurrence of breast cancer after radiotherapy is considered to be related with radioresistance in breast cancer cells. Various factors, extranuclear and intranuclear, such as insulin-like growth factor-1 receptor, phosphatidylinositol 3-kinase pathway, epidermal growth factor, human epidermal growth factor receptors, p53, c-erb B2, Bcl-2, BRCA1, BRCA2, telomeres and gene expression signature, that have been implicated to influence the radiation response. (authors)

  18. Fuel Cell Balance-of-Plant Reliability Testbed Project

    Energy Technology Data Exchange (ETDEWEB)

    Sproat, Vern [Stark State College of Technology, North Canton, OH (United States); LaHurd, Debbie [Lockheed Martin Corp., Oak Ridge, TN (United States)

    2016-10-29

    Reliability of the fuel cell system balance-of-plant (BoP) components is a critical factor that needs to be addressed prior to fuel cells becoming fully commercialized. Failure or performance degradation of BoP components has been identified as a life-limiting factor in fuel cell systems.1 The goal of this project is to develop a series of test beds that will test system components such as pumps, valves, sensors, fittings, etc., under operating conditions anticipated in real Polymer Electrolyte Membrane (PEM) fuel cell systems. Results will be made generally available to begin removing reliability as a roadblock to the growth of the PEM fuel cell industry. Stark State College students participating in the project, in conjunction with their coursework, have been exposed to technical knowledge and training in the handling and maintenance of hydrogen, fuel cells and system components as well as component failure modes and mechanisms. Three test beds were constructed. Testing was completed on gas flow pumps, tubing, and pressure and temperature sensors and valves.

  19. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

    Energy Technology Data Exchange (ETDEWEB)

    De Schamphelaere, K.A.C., E-mail: karel.deschamphelaere@Ugent.be [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium); Stubblefield, W. [Oregon State University, Department of Environmental and Molecular Toxicology, 421 Weniger Hall, Corvallis, OR 97331 (United States); Rodriguez, P. [Centro de Investigacion Minera y Metalurgica (CIMM), Santiago (Chile); Vleminckx, K. [Department for Molecular Biomedical Research, Ghent University (Belgium); Janssen, C.R. [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium)

    2010-10-15

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO{sub 4}{sup 2-}). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na{sub 2}MoO{sub 4}.2H{sub 2}O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21 day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7 day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72 h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48 h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14 day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28 day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4 day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7 day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34 day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78 day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data

  20. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

    International Nuclear Information System (INIS)

    De Schamphelaere, K.A.C.; Stubblefield, W.; Rodriguez, P.; Vleminckx, K.; Janssen, C.R.

    2010-01-01

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO 4 2- ). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na 2 MoO 4 .2H 2 O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21 day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7 day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72 h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48 h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14 day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28 day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4 day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7 day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34 day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78 day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data presented in this

  1. The FDI-growth hypothesis: A VAR model for Nigeria

    Directory of Open Access Journals (Sweden)

    PA Olomola

    2004-07-01

    Full Text Available The objective of this study was to examine the causal relationship between foreign direct investment and economic growth in Nigeria using annual data covering the period 1970 to 2002. The study employed the Granger causality procedure to test the direction of causality between foreign direct investment and economic growth for the Nigerian economy. The endogenous production function was derived to accommodate foreign investment and other domestic policies that could influence growth and foreign investment. The study found a one-way causality between from foreign direct investment to economic growth. The implication arising from this study is that Nigeria should adopt policy whereby FDI is attracted to promote economic growth.

  2. Urban Teens: Trauma, Posttraumatic Growth, and Emotional Distress among Female Adolescents

    Science.gov (United States)

    Ickovics, Jeanette R.; Meade, Christina S.; Kershaw, Trace S.; Milan, Stephanie; Lewis, Jessica B.; Ethier, Kathleen A.

    2006-01-01

    Urban teens face many traumas, with implications for potential growth and distress. This study examined traumatic events, posttraumatic growth, and emotional distress over 18 months among urban adolescent girls (N = 328). Objectives were to (a) describe types of traumatic events, (b) determine how type and timing of events relate to profiles of…

  3. Reliability of electronic systems

    International Nuclear Information System (INIS)

    Roca, Jose L.

    2001-01-01

    Reliability techniques have been developed subsequently as a need of the diverse engineering disciplines, nevertheless they are not few those that think they have been work a lot on reliability before the same word was used in the current context. Military, space and nuclear industries were the first ones that have been involved in this topic, however not only in these environments it is that it has been carried out this small great revolution in benefit of the increase of the reliability figures of the products of those industries, but rather it has extended to the whole industry. The fact of the massive production, characteristic of the current industries, drove four decades ago, to the fall of the reliability of its products, on one hand, because the massively itself and, for other, to the recently discovered and even not stabilized industrial techniques. Industry should be changed according to those two new requirements, creating products of medium complexity and assuring an enough reliability appropriated to production costs and controls. Reliability began to be integral part of the manufactured product. Facing this philosophy, the book describes reliability techniques applied to electronics systems and provides a coherent and rigorous framework for these diverse activities providing a unifying scientific basis for the entire subject. It consists of eight chapters plus a lot of statistical tables and an extensive annotated bibliography. Chapters embrace the following topics: 1- Introduction to Reliability; 2- Basic Mathematical Concepts; 3- Catastrophic Failure Models; 4-Parametric Failure Models; 5- Systems Reliability; 6- Reliability in Design and Project; 7- Reliability Tests; 8- Software Reliability. This book is in Spanish language and has a potentially diverse audience as a text book from academic to industrial courses. (author)

  4. Nonlinear Dynamics and the Growth of Literature.

    Science.gov (United States)

    Tabah, Albert N.

    1992-01-01

    Discussion of nonlinear dynamic mechanisms focuses on whether information production and dissemination can be described by similar mechanisms. The exponential versus linear growth of literature is discussed, the time factor is considered, an example using literature from the field of superconductivity is given, and implications for information…

  5. Economics of Sustainable Development. Competitiveness and Economic Growth

    Directory of Open Access Journals (Sweden)

    Dorel AILENEI

    2011-02-01

    Full Text Available Economic growth is one of the most important issues of humanity. Both in national economies and world economy, recession and prosperity periods are regularly succeeding with different amplitudes. But beyond these fluctuations and their effects, the results are important: performance and economic growth. Because of the problematical issue of economic growth, the authors are trying to critically reflect on the economic growth concept and on its implications on the praxis area. Although there is a large literature about economic growth modeling, it is intriguing that there still are some serious obstacles for conceptualization and praxis. Only the simple fact that the economic growth process needs serious thinking on the time dimension is sufficient for understanding the real difficulties of this problematical issue. As for the economic growth praxis, a clear analysis of the interests system within an economy is needed. Without trying to find miraculous solutions for the economic growth issue, the authors suggest a clear and correct analysis of this important subject.

  6. Nuclear energy consumption, oil consumption and economic growth in G-6 countries: Bootstrap panel causality test

    International Nuclear Information System (INIS)

    Chu, Hsiao-Ping; Chang Tsangyao

    2012-01-01

    This study applies bootstrap panel Granger causality to test whether energy consumption promotes economic growth using data from G-6 countries over the period of 1971–2010. Both nuclear and oil consumption data are used in this study. Regarding the nuclear consumption-economic growth nexus, nuclear consumption causes economic growth in Japan, the UK, and the US; economic growth causes nuclear consumption in the US; nuclear consumption and economic growth show no causal relation in Canada, France and Germany. Regarding oil consumption-economic growth nexus, we find that there is one-way causality from economic growth to oil consumption only in the US, and that oil consumption does not Granger cause economic growth in G-6 countries except Germany and Japan. Our results have important policy implications for the G-6 countries within the context of economic development. - Highlights: ► Bootstrap panel Granger causality test whether energy consumption promotes economic growth. ► Data from G-6 countries for both nuclear and oil consumption data are used. ► Results have important policy implications within the context of economic development.

  7. Growth of cortical neuronal network in vitro: Modeling and analysis

    International Nuclear Information System (INIS)

    Lai, P.-Y.; Jia, L. C.; Chan, C. K.

    2006-01-01

    We present a detailed analysis and theoretical growth models to account for recent experimental data on the growth of cortical neuronal networks in vitro [Phys. Rev. Lett. 93, 088101 (2004)]. The experimentally observed synchronized firing frequency of a well-connected neuronal network is shown to be proportional to the mean network connectivity. The growth of the network is consistent with the model of an early enhanced growth of connection, but followed by a retarded growth once the synchronized cluster is formed. Microscopic models with dominant excluded volume interactions are consistent with the observed exponential decay of the mean connection probability as a function of the mean network connectivity. The biological implications of the growth model are also discussed

  8. Empirical testing of Kotler's high-performance factors to increase sales growth

    Directory of Open Access Journals (Sweden)

    Oren Dayan

    2010-12-01

    Full Text Available Purpose and/or objectives: The primary objective of this study is to empirically test Kotler's (2003 high-performance model which ensures an increase in sales growth. More specifically, the study explores the influence of process variables (as measured by marketing strategies, resources management (as measured by the management of labour, materials, machines, information technology and energy and organisational variables (as measured by TQM and organisational culture on sales growth in the food, motorcar and high-technology manufacturing industries. Problem investigated Various research studies suggest that the managers of firms are continuously challenged in their attempts to increase their sales (Morre, 2007; Pauwels, Silva Risso, Srinivasan & Hanssens, 2004: 142-143; Gray & Hayes, 2007: 1. Kotler (2003 suggests a model that leads to a high performing business. The question is posed as to whether this model can be used to increase sales growth in all businesses. This study seeks to develop a generic model to increase sales growth across industries by using an adapted version of Kotler's (2003 high-performance model. The study investigates the application of this adapted model on the food, motorcar and high-technology manufacturing industries. Design and/or methodology and/or approach: An empirical causal research design that includes 770 marketing and product development practitioners from multinational food, motorcar and high-technology manufacturing firms, was used in this study. A response rate of 76.1% was achieved as only 571 useable questionnaires were returned. The internal reliability and discriminant validity of the measuring instrument were assessed by the calculation of Cronbach alpha coefficients and the conducting an exploratory factor analysis respectively. Structural Equation Modelling SEM was used to statistically test the relationships between the independent variables (marketing strategies, resource management, TQM and

  9. Analysis and Application of Reliability

    International Nuclear Information System (INIS)

    Jeong, Hae Seong; Park, Dong Ho; Kim, Jae Ju

    1999-05-01

    This book tells of analysis and application of reliability, which includes definition, importance and historical background of reliability, function of reliability and failure rate, life distribution and assumption of reliability, reliability of unrepaired system, reliability of repairable system, sampling test of reliability, failure analysis like failure analysis by FEMA and FTA, and cases, accelerated life testing such as basic conception, acceleration and acceleration factor, and analysis of accelerated life testing data, maintenance policy about alternation and inspection.

  10. Plant Growth Research for Food Production: Development and Testing of Expandable Tuber Growth Module

    Science.gov (United States)

    Cordova, Brennan A.

    2017-01-01

    Controlled and reliable growth of a variety of vegetable crops is an important capability for manned deep space exploration systems for providing nutritional supplementation and psychological benefits to crew members. Because current systems have been limited to leafy vegetables that require minimal root space, a major goal for these systems is to increase their ability to grow new types of crops, including tuber plants and root vegetables that require a large root space. An expandable root zone module and housing was developed to integrate this capability into the Veggie growth system. The expandable module uses a waterproof, gas-permeable bag with a structure that allows for root space to increase vertically throughout the growth cycle to accommodate for expanding tuber growth, while minimizing the required media mass. Daikon radishes were chosen as an ideal tuber crop for their subterraneous tuber size and rapid growth cycle, and investigations were done to study expanding superabsorbent hydrogels as a potential growth media. These studies showed improved water retention, but restricted oxygen availability to roots with pure gel media. It was determined that these hydrogels could be integrated in lower proportions into standard soil to achieve media expansion and water retention desired. Using the constructed module prototype and ideal gel and soil media mixture, Daikon radishes were grown in the system to test the capability and success of the system through a full growth cycle.

  11. Reliability in automotive and mechanical engineering determination of component and system reliability

    CERN Document Server

    Bertsche, Bernd

    2008-01-01

    In the present contemporary climate of global competition in every branch of engineering and manufacture it has been shown from extensive customer surveys that above every other attribute, reliability stands as the most desired feature in a finished product. To survive this relentless fight for survival any organisation, which neglect the plea of attaining to excellence in reliability, will do so at a serious cost Reliability in Automotive and Mechanical Engineering draws together a wide spectrum of diverse and relevant applications and analyses on reliability engineering. This is distilled into this attractive and well documented volume and practising engineers are challenged with the formidable task of simultaneously improving reliability and reducing the costs and down-time due to maintenance. The volume brings together eleven chapters to highlight the importance of the interrelated reliability and maintenance disciplines. They represent the development trends and progress resulting in making this book ess...

  12. Inflation, inflation uncertainty and output growth in the USA

    Science.gov (United States)

    Bhar, Ramprasad; Mallik, Girijasankar

    2010-12-01

    Employing a multivariate EGARCH-M model, this study investigates the effects of inflation uncertainty and growth uncertainty on inflation and output growth in the United States. Our results show that inflation uncertainty has a positive and significant effect on the level of inflation and a negative and significant effect on the output growth. However, output uncertainty has no significant effect on output growth or inflation. The oil price also has a positive and significant effect on inflation. These findings are robust and have been corroborated by use of an impulse response function. These results have important implications for inflation-targeting monetary policy, and the aim of stabilization policy in general.

  13. BIOCHEMICAL HOMEOSTASIS AND BODY GROWTH ARE RELIABLE END POINTS IN CLINICAL NUTRITION TRIALS

    Science.gov (United States)

    Studies of biochemical homeostasis and/or body growth have been included as outcome variables in most nutrition trials in paediatric patients. Moreover, these outcome variables have provided important insights into the nutrient requirements of infants and children, and continue to do so. Examples ...

  14. Microelectronics Reliability

    Science.gov (United States)

    2017-01-17

    inverters  connected in a chain. ................................................. 5  Figure 3  Typical graph showing frequency versus square root of...developing an experimental  reliability estimating methodology that could both illuminate the  lifetime  reliability of advanced devices,  circuits and...or  FIT of the device. In other words an accurate estimate of the device  lifetime  was found and thus the  reliability  that  can  be  conveniently

  15. Human reliability analysis

    International Nuclear Information System (INIS)

    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

  16. Developments in our understanding of the effects of growth hormone on white adipose tissue from mice: implications to the clinic.

    Science.gov (United States)

    Berryman, Darlene E; Henry, Brooke; Hjortebjerg, Rikke; List, Edward O; Kopchick, John J

    2016-01-01

    Adipose tissue (AT) is a well-established target of growth hormone (GH) and is altered in clinical conditions associated with excess, deficiency and absence of GH action. Due to the difficulty in collecting AT from clinical populations, genetically modified mice have been useful in better understanding how GH affects this tissue. Recent findings in mice would suggest that the impact of GH on AT is beyond alterations of lipolysis, lipogenesis or proliferation/ differentiation. AT depot-specific alterations in immune cells, extracellular matrix, adipokines, and senescence indicate an expanded role for GH in AT physiology. This mouse data will guide additional studies necessary to evaluate the therapeutic potential and safety of GH for conditions associated with altering AT, such as obesity. In this review, we introduce several relatively new intricacies of GH's effect on AT, focusing on recent studies in mice. Finally, we summarize the clinical implications of these findings.

  17. Hawaii Electric System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Loose, Verne William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silva Monroy, Cesar Augusto [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2012-08-01

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

  18. How often should we monitor for reliable detection of atrial fibrillation recurrence? Efficiency considerations and implications for study design.

    Directory of Open Access Journals (Sweden)

    Efstratios I Charitos

    Full Text Available Although atrial fibrillation (AF recurrence is unpredictable in terms of onset and duration, current intermittent rhythm monitoring (IRM diagnostic modalities are short-termed and discontinuous. The aim of the present study was to investigate the necessary IRM frequency required to reliably detect recurrence of various AF recurrence patterns.The rhythm histories of 647 patients (mean AF burden: 12 ± 22% of monitored time; 687 patient-years with implantable continuous monitoring devices were reconstructed and analyzed. With the use of computationally intensive simulation, we evaluated the necessary IRM frequency to reliably detect AF recurrence of various AF phenotypes using IRM of various durations.The IRM frequency required for reliable AF detection depends on the amount and temporal aggregation of the AF recurrence (p95% sensitivity of AF recurrence required higher IRM frequencies (>12 24-hour; >6 7-day; >4 14-day; >3 30-day IRM per year; p<0.0001 than currently recommended. Lower IRM frequencies will under-detect AF recurrence and introduce significant bias in the evaluation of therapeutic interventions. More frequent but of shorter duration, IRMs (24-hour are significantly more time effective (sensitivity per monitored time than a fewer number of longer IRM durations (p<0.0001.Reliable AF recurrence detection requires higher IRM frequencies than currently recommended. Current IRM frequency recommendations will fail to diagnose a significant proportion of patients. Shorter duration but more frequent IRM strategies are significantly more efficient than longer IRM durations.Unique identifier: NCT00806689.

  19. Dynamic reliability assessment and prediction for repairable systems with interval-censored data

    International Nuclear Information System (INIS)

    Peng, Yizhen; Wang, Yu; Zi, YanYang; Tsui, Kwok-Leung; Zhang, Chuhua

    2017-01-01

    The ‘Test, Analyze and Fix’ process is widely applied to improve the reliability of a repairable system. In this process, dynamic reliability assessment for the system has been paid a great deal of attention. Due to instrument malfunctions, staff omissions and imperfect inspection strategies, field reliability data are often subject to interval censoring, making dynamic reliability assessment become a difficult task. Most traditional methods assume this kind of data as multiple normal distributed variables or the missing mechanism as missing at random, which may cause a large bias in parameter estimation. This paper proposes a novel method to evaluate and predict the dynamic reliability of a repairable system subject to interval-censored problem. First, a multiple imputation strategy based on the assumption that the reliability growth trend follows a nonhomogeneous Poisson process is developed to derive the distributions of missing data. Second, a new order statistic model that can transfer the dependent variables into independent variables is developed to simplify the imputation procedure. The unknown parameters of the model are iteratively inferred by the Monte Carlo expectation maximization (MCEM) algorithm. Finally, to verify the effectiveness of the proposed method, a simulation and a real case study for gas pipeline compressor system are implemented. - Highlights: • A new multiple imputation strategy was developed to derive the PDF of missing data. • A new order statistic model was developed to simplify the imputation procedure. • The parameters of the order statistic model were iteratively inferred by MCEM. • A real cases study was conducted to verify the effectiveness of the proposed method.

  20. Reliability and safety engineering

    CERN Document Server

    Verma, Ajit Kumar; Karanki, Durga Rao

    2016-01-01

    Reliability and safety are core issues that must be addressed throughout the life cycle of engineering systems. Reliability and Safety Engineering presents an overview of the basic concepts, together with simple and practical illustrations. The authors present reliability terminology in various engineering fields, viz.,electronics engineering, software engineering, mechanical engineering, structural engineering and power systems engineering. The book describes the latest applications in the area of probabilistic safety assessment, such as technical specification optimization, risk monitoring and risk informed in-service inspection. Reliability and safety studies must, inevitably, deal with uncertainty, so the book includes uncertainty propagation methods: Monte Carlo simulation, fuzzy arithmetic, Dempster-Shafer theory and probability bounds. Reliability and Safety Engineering also highlights advances in system reliability and safety assessment including dynamic system modeling and uncertainty management. Cas...

  1. A Systematic Review of Statistical Methods Used to Test for Reliability of Medical Instruments Measuring Continuous Variables

    Directory of Open Access Journals (Sweden)

    Rafdzah Zaki

    2013-06-01

    Full Text Available   Objective(s: Reliability measures precision or the extent to which test results can be replicated. This is the first ever systematic review to identify statistical methods used to measure reliability of equipment measuring continuous variables. This studyalso aims to highlight the inappropriate statistical method used in the reliability analysis and its implication in the medical practice.   Materials and Methods: In 2010, five electronic databases were searched between 2007 and 2009 to look for reliability studies. A total of 5,795 titles were initially identified. Only 282 titles were potentially related, and finally 42 fitted the inclusion criteria. Results: The Intra-class Correlation Coefficient (ICC is the most popular method with 25 (60% studies having used this method followed by the comparing means (8 or 19%. Out of 25 studies using the ICC, only 7 (28% reported the confidence intervals and types of ICC used. Most studies (71% also tested the agreement of instruments. Conclusion: This study finds that the Intra-class Correlation Coefficient is the most popular method used to assess the reliability of medical instruments measuring continuous outcomes. There are also inappropriate applications and interpretations of statistical methods in some studies. It is important for medical researchers to be aware of this issue, and be able to correctly perform analysis in reliability studies.

  2. Merlino-Perkins Father-Daughter Relationship Inventory (MP-FDI): Construction, Reliability, Validity, and Implications for Counseling and Research

    Science.gov (United States)

    Merlino Perkins, Rose J.

    2008-01-01

    The Merlino-Perkins Father-Daughter Relationship Inventory, a self-report instrument, assesses women's childhood interactions with supportive, doting, distant, controlling, tyrannical, physically abusive, absent, and seductive fathers. Item and scale development, psychometric findings drawn from factor analyses, reliability assessments, and…

  3. Land Cover Change and Remote Sensing in the Classroom: An Exercise to Study Urban Growth

    Science.gov (United States)

    Delahunty, Tina; Lewis-Gonzales, Sarah; Phelps, Jack; Sawicki, Ben; Roberts, Charles; Carpenter, Penny

    2012-01-01

    The processes and implications of urban growth are studied in a variety of disciplines as urban growth affects both the physical and human landscape. Remote sensing methods provide ways to visualize and mathematically represent urban growth; and resultant land cover change data enable both quantitative and qualitative analysis. This article helps…

  4. Crop residue harvest for bioenergy production and its implications on soil functioning and plant growth: A review

    Directory of Open Access Journals (Sweden)

    Maurício Roberto Cherubin

    Full Text Available ABSTRACT: The use of crop residues as a bioenergy feedstock is considered a potential strategy to mitigate greenhouse gas (GHG emissions. However, indiscriminate harvesting of crop residues can induce deleterious effects on soil functioning, plant growth and other ecosystem services. Here, we have summarized the information available in the literature to identify and discuss the main trade-offs and synergisms involved in crop residue management for bioenergy production. The data consistently showed that crop residue harvest and the consequent lower input of organic matter into the soil led to C storage depletions over time, reducing cycling, supply and availability of soil nutrients, directly affecting the soil biota. Although the biota regulates key functions in the soil, crop residue can also cause proliferation of some important agricultural pests. In addition, crop residues act as physical barriers that protect the soil against raindrop impact and temperature variations. Therefore, intensive crop residue harvest can cause soil structure degradation, leading to soil compaction and increased risks of erosion. With regard to GHG emissions, there is no consensus about the potential impact of management of crop residue harvest. In general, residue harvest decreases CO2 and N2O emissions from the decomposition process, but it has no significant effect on CH4 emissions. Plant growth responses to soil and microclimate changes due to crop residue harvest are site and crop specific. Adoption of the best management practices can mitigate the adverse impacts of crop residue harvest. Longterm experiments within strategic production regions are essential to understand and monitor the impact of integrated agricultural systems and propose customized solutions for sustainable crop residue management in each region or landscape. Furthermore, private and public investments/cooperations are necessary for a better understanding of the potential environmental

  5. OSS reliability measurement and assessment

    CERN Document Server

    Yamada, Shigeru

    2016-01-01

    This book analyses quantitative open source software (OSS) reliability assessment and its applications, focusing on three major topic areas: the Fundamentals of OSS Quality/Reliability Measurement and Assessment; the Practical Applications of OSS Reliability Modelling; and Recent Developments in OSS Reliability Modelling. Offering an ideal reference guide for graduate students and researchers in reliability for open source software (OSS) and modelling, the book introduces several methods of reliability assessment for OSS including component-oriented reliability analysis based on analytic hierarchy process (AHP), analytic network process (ANP), and non-homogeneous Poisson process (NHPP) models, the stochastic differential equation models and hazard rate models. These measurement and management technologies are essential to producing and maintaining quality/reliable systems using OSS.

  6. Reliability and equivalence of alternate forms for the Symbol Digit Modalities Test: implications for multiple sclerosis clinical trials.

    Science.gov (United States)

    Benedict, Ralph H B; Smerbeck, Audrey; Parikh, Rajavi; Rodgers, Jonathan; Cadavid, Diego; Erlanger, David

    2012-09-01

    Cognitive impairment is common in multiple sclerosis (MS), but is seldom assessed in clinical trials investigating the effects of disease-modifying therapies. The Symbol Digit Modalities Test (SDMT) is a particularly promising tool due to its sensitivity and robust correlation with brain magnetic resonance imaging (MRI) and vocational disability. Unfortunately, there are no validated alternate SDMT forms, which are needed to mitigate practice effects. The aim of the study was to assess the reliability and equivalence of SDMT alternate forms. Twenty-five healthy participants completed each of five alternate versions of the SDMT - the standard form, two versions from the Rao Brief Repeatable Battery, and two forms specifically designed for this study. Order effects were controlled using a Latin-square research design. All five versions of the SDMT produced mean values within 3 raw score points of one another. Three forms were very consistent, and not different by conservative statistical tests. The SDMT test-retest reliability using these forms was good to excellent, with all r values exceeding 0.80. For the first time, we find good evidence that at least three alternate versions of the SDMT are of equivalent difficulty in healthy adults. The forms are reliable, and can be implemented in clinical trials emphasizing cognitive outcomes.

  7. Scoping study on trends in the economic value of electricity reliability to the U.S. economy; TOPICAL

    International Nuclear Information System (INIS)

    Eto, Joseph; Koomey, Jonathan; Lehman, Bryan; Martin, Nathan; Mills, Evan; Webber, Carrie; Worrell, Ernst

    2001-01-01

    During the past three years, working with more than 150 organizations representing public and private stakeholders, EPRI has developed the Electricity Technology Roadmap. The Roadmap identifies several major strategic challenges that must be successfully addressed to ensure a sustainable future in which electricity continues to play an important role in economic growth. Articulation of these anticipated trends and challenges requires a detailed understanding of the role and importance of reliable electricity in different sectors of the economy. This report is intended to contribute to that understanding by analyzing key aspects of trends in the economic value of electricity reliability in the U.S. economy. We first present a review of recent literature on electricity reliability costs. Next, we describe three distinct end-use approaches for tracking trends in reliability needs: (1) an analysis of the electricity-use requirements of office equipment in different commercial sectors; (2) an examination of the use of aggregate statistical indicators of industrial electricity use and economic activity to identify high reliability-requirement customer market segments; and (3) a case study of cleanrooms, which is a cross-cutting market segment known to have high reliability requirements. Finally, we present insurance industry perspectives on electricity reliability as an example of a financial tool for addressing customers' reliability needs

  8. Reliability and risk functions for structural components taking into account inspection results

    International Nuclear Information System (INIS)

    Rackwitz, R.; Schall, G.

    1989-01-01

    The method of outcrossings has been shown to be efficient when calculating the failure probability of metallic structural components under ergodic Gaussian loading. Using Paris/Erdogan's crack growth law it is possible to develop a semi-analytical calculation model for both the reliability and the risk function. For numerical studies an approximate method of asymptotic nature is proposed. The same methodology also enables to incorporate inspection observations. (orig.) [de

  9. Reliability of software

    International Nuclear Information System (INIS)

    Kopetz, H.

    1980-01-01

    Common factors and differences in the reliability of hardware and software; reliability increase by means of methods of software redundancy. Maintenance of software for long term operating behavior. (HP) [de

  10. Does gender inequality hinder development and economic growth ? evidence and policy implications

    OpenAIRE

    Bandiera, Oriana; Natraj, Ashwini

    2013-01-01

    Does the existing evidence support policies that foster growth by reducing gender inequality? The authors argue that the evidence based on differences across countries is of limited use for policy design because it does not identify the causal link from inequality to growth. This, however does not imply that inequality-reducing policies are ineffective. In other words, the lack of evidence...

  11. Hawaii electric system reliability.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Reliability assessment of a multistate freight network for perishable merchandise with multiple suppliers and buyers

    Science.gov (United States)

    Lin, Yi-Kuei; Yeh, Cheng-Ta; Huang, Cheng-Fu

    2017-01-01

    This study develops a multistate freight network for single and perishable merchandise to assess the freight performance, where a node denotes a supplier, a distribution centre, or a buyer, while a logistics company providing a freight traffic service is denoted by an edge. For each logistics company, carrying capacity should be multistate since partial capacity may be reserved by some customers. The merchandise may perish or be perished during conveyance because of disadvantageous weather or collision in carrying such that the number of intact cargoes may be insufficient for the buyers. Hence, according to the perspective of supply chain management, the reliability, a probability of the network to successfully deliver the cargoes from the suppliers to the buyers subject to a budget, is proposed to be a performance index, where the suppliers and buyers are not the previous customers. An algorithm in terms of minimal paths to assess the reliability is developed. A fruit logistics case is adopted to explore the managerial implications of the reliability using sensitivity analysis.

  13. Use of Raman Spectroscopy and Delta Volume Growth from Void Collapse to Assess Overwrap Stress Gradients Compromising the Reliability of Large Kevlar/Epoxy COPVs

    Science.gov (United States)

    Kezirian, Michael T.; Phoenix, S. Leigh; Eldridge, Jeffrey I.

    2009-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are frequently used for storing pressurized gases aboard spacecraft and aircraft when weight saving is desirable compared to all-metal versions. Failure mechanisms in fibrous COPVs and variability in lifetime can be very different from their metallic counterparts; in the former, catastrophic stress-rupture can occur with virtually no warning, whereas in latter, a leak before burst design philosophy can be implemented. Qualification and certification typically requires only one burst test on a production sample (possibly after several pressure cycles) and the vessel need only meet a design burst strength (the maximum operating pressure divided by a knockdown factor). Typically there is no requirement to assess variability in burst strength or lifetime, much less determine production and materials processing parameters important to control of such variability. Characterizing such variability and its source is crucial to models for calculating required reliability over a given lifetime (e.g. R = 0.9999 for 15 years). In this paper we present a case study of how lack of control of certain process parameters in COPV manufacturing can result in variations among vessels and between production runs that can greatly increase uncertainty and reduce reliability. The vessels considered are 40-inch ( NASA Glenn Research center, Cleveland, OH, 44135 29,500 in3 ) spherical COPVs with a 0.74 in. thick Kevlar49/epoxy overwrap and with a titanium liner of which 34 were originally produced. Two burst tests were eventually performed that unexpectedly differed by almost 5%, and were 10% lower than anticipated from burst tests on 26-inch sister vessels similar in every detail. A major observation from measurements made during proof testing (autofrettage) of the 40-inch vessels was that permanent volume growth from liner yielding varied by a factor of more than two (150 in3 to 360 in3 ), which suggests large differences in the residual

  14. Human factor reliability program

    International Nuclear Information System (INIS)

    Knoblochova, L.

    2017-01-01

    The human factor's reliability program was at Slovenske elektrarne, a.s. (SE) nuclear power plants. introduced as one of the components Initiatives of Excellent Performance in 2011. The initiative's goal was to increase the reliability of both people and facilities, in response to 3 major areas of improvement - Need for improvement of the results, Troubleshooting support, Supporting the achievement of the company's goals. The human agent's reliability program is in practice included: - Tools to prevent human error; - Managerial observation and coaching; - Human factor analysis; -Quick information about the event with a human agent; -Human reliability timeline and performance indicators; - Basic, periodic and extraordinary training in human factor reliability(authors)

  15. Adaptation of the ToxRTool to Assess the Reliability of Toxicology Studies Conducted with Genetically Modified Crops and Implications for Future Safety Testing.

    Science.gov (United States)

    Koch, Michael S; DeSesso, John M; Williams, Amy Lavin; Michalek, Suzanne; Hammond, Bruce

    2016-01-01

    To determine the reliability of food safety studies carried out in rodents with genetically modified (GM) crops, a Food Safety Study Reliability Tool (FSSRTool) was adapted from the European Centre for the Validation of Alternative Methods' (ECVAM) ToxRTool. Reliability was defined as the inherent quality of the study with regard to use of standardized testing methodology, full documentation of experimental procedures and results, and the plausibility of the findings. Codex guidelines for GM crop safety evaluations indicate toxicology studies are not needed when comparability of the GM crop to its conventional counterpart has been demonstrated. This guidance notwithstanding, animal feeding studies have routinely been conducted with GM crops, but their conclusions on safety are not always consistent. To accurately evaluate potential risks from GM crops, risk assessors need clearly interpretable results from reliable studies. The development of the FSSRTool, which provides the user with a means of assessing the reliability of a toxicology study to inform risk assessment, is discussed. Its application to the body of literature on GM crop food safety studies demonstrates that reliable studies report no toxicologically relevant differences between rodents fed GM crops or their non-GM comparators.

  16. Divergent growth of Norway spruce on Babia Góra Mountain in the western Carpathians

    NARCIS (Netherlands)

    Buras, Allan; Spyt, Barbara; Janecka, Karolina; Kaczka, Ryszard

    2018-01-01

    Growth divergence – i.e. the expression of divergent growth trends of neighboring trees – has certain implications for dendrochronological research, for instance in the context of climate reconstructions but also in terms of estimating net ecosystem productivity. Thus, understanding the underlying

  17. Phytochrome, plant growth and flowering

    Science.gov (United States)

    King, R. W.; Bagnall, D. J.

    1994-01-01

    Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. With FR depletion plants grown in sunlight are small, more branched and darker green. Here we examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.

  18. Phytochrome, plant growth and flowering

    Energy Technology Data Exchange (ETDEWEB)

    King, R.W.; Bagnall, D.J. [CSIRO, Canberra (Australia)

    1994-12-31

    Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. As shown for chrysanthemum, with FR depletion plants grown in sunlight are small, more branched and darker green. We examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.

  19. Linkages between financial development, financial instability, financial liberalisation and economic growth in Africa

    OpenAIRE

    Enowbi Batuo, M.; Mlambo, Kupukile; Asongu, Simplice

    2017-01-01

    In the aftermath of the 2008 global financial crisis, the implications of financial liberalisation for stability and economic growth has come under increased scrutiny. One strand of literature posits a positive relationship between financial liberalisation and economic growth and development. However, others emphasise the link between financial liberalisation is intrinsically associated with financial instability which may be harmful to economic growth and development. This study assesses ...

  20. Reliability of isometric lower-extremity muscle strength measurements in children with cerebral palsy: implications for measurement design

    NARCIS (Netherlands)

    Willemse, Lydia; Brehm, Merel A.; Scholtes, Vanessa A.; Jansen, Laura; Woudenberg-Vos, Hester; Dallmeijer, Annet J.

    2013-01-01

    Children with cerebral palsy (CP) typically show muscle weakness of the lower extremities, which can be measured with the use of handheld dynamometry (HHD). The purposes of this study were: (1) to determine test-retest reliability and measurement error of isometric lower-extremity strength

  1. Reliable Design Versus Trust

    Science.gov (United States)

    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?

  2. Complement-mediated tumour growth: implications for cancer nanotechnology and nanomedicines

    DEFF Research Database (Denmark)

    Moghimi, S. M.; Andresen, Thomas Lars

    2009-01-01

    The recent unexpected observation that complement activation helps turnout growth and progression has an important bearing on the future development of cancer nanomedicines for site-specific tumour targeting as these entities are capable of triggering complement. These issues are discussed and su...

  3. Reliability-Based Code Calibration

    DEFF Research Database (Denmark)

    Faber, M.H.; Sørensen, John Dalsgaard

    2003-01-01

    The present paper addresses fundamental concepts of reliability based code calibration. First basic principles of structural reliability theory are introduced and it is shown how the results of FORM based reliability analysis may be related to partial safety factors and characteristic values....... Thereafter the code calibration problem is presented in its principal decision theoretical form and it is discussed how acceptable levels of failure probability (or target reliabilities) may be established. Furthermore suggested values for acceptable annual failure probabilities are given for ultimate...... and serviceability limit states. Finally the paper describes the Joint Committee on Structural Safety (JCSS) recommended procedure - CodeCal - for the practical implementation of reliability based code calibration of LRFD based design codes....

  4. Human reliability

    International Nuclear Information System (INIS)

    Bubb, H.

    1992-01-01

    This book resulted from the activity of Task Force 4.2 - 'Human Reliability'. This group was established on February 27th, 1986, at the plenary meeting of the Technical Reliability Committee of VDI, within the framework of the joint committee of VDI on industrial systems technology - GIS. It is composed of representatives of industry, representatives of research institutes, of technical control boards and universities, whose job it is to study how man fits into the technical side of the world of work and to optimize this interaction. In a total of 17 sessions, information from the part of ergonomy dealing with human reliability in using technical systems at work was exchanged, and different methods for its evaluation were examined and analyzed. The outcome of this work was systematized and compiled in this book. (orig.) [de

  5. The role of strategic management on small business growth in Kosova

    Directory of Open Access Journals (Sweden)

    Enver Kutllovci, Ph.D

    2013-07-01

    Full Text Available Small and medium enterprises (SMEs are considered to be the engine of economic growth through employment generation, contribution to GDP, technological innovations and other aspects of economic and social development. SMEs are also important because they are key drivers of employment and economic growth. The growth of SMEs depends on ability of those firms to apply strategic planning. In that context, strategic planning is very important for small and medium enterpriese in the time of global competition, technological change and increased dynamics in markets. Even if many entrepreneurs do not formulate business plans, the strategic planning and systematic decision-making can be considered a key determinant of survival and success of small firms. The paper examines the relationship between strategic planning and small and medium enterprises (SME growth in terms of empirical analyses that include various strategic planning elements.The study has practical implications. Entrepreneurs need to be aware that strategic planning practices, processes and techniques can be beneficial for growth of the firm. In order to enable their firms to grow, entrepreneurs may like to consider exactly formulating strategy, focusing on growth, profit, and market, among strategic analysis techniques paying special attention to analysis of market and competition and exactly formulating generic business strategies The key implication of this study for research is that the assessment of the relationship between strategic planning and small firm growth needs to be done across various elements or dimensions.

  6. Reliability of infarct volumetry: Its relevance and the improvement by a software-assisted approach.

    Science.gov (United States)

    Friedländer, Felix; Bohmann, Ferdinand; Brunkhorst, Max; Chae, Ju-Hee; Devraj, Kavi; Köhler, Yvette; Kraft, Peter; Kuhn, Hannah; Lucaciu, Alexandra; Luger, Sebastian; Pfeilschifter, Waltraud; Sadler, Rebecca; Liesz, Arthur; Scholtyschik, Karolina; Stolz, Leonie; Vutukuri, Rajkumar; Brunkhorst, Robert

    2017-08-01

    Despite the efficacy of neuroprotective approaches in animal models of stroke, their translation has so far failed from bench to bedside. One reason is presumed to be a low quality of preclinical study design, leading to bias and a low a priori power. In this study, we propose that the key read-out of experimental stroke studies, the volume of the ischemic damage as commonly measured by free-handed planimetry of TTC-stained brain sections, is subject to an unrecognized low inter-rater and test-retest reliability with strong implications for statistical power and bias. As an alternative approach, we suggest a simple, open-source, software-assisted method, taking advantage of automatic-thresholding techniques. The validity and the improvement of reliability by an automated method to tMCAO infarct volumetry are demonstrated. In addition, we show the probable consequences of increased reliability for precision, p-values, effect inflation, and power calculation, exemplified by a systematic analysis of experimental stroke studies published in the year 2015. Our study reveals an underappreciated quality problem in translational stroke research and suggests that software-assisted infarct volumetry might help to improve reproducibility and therefore the robustness of bench to bedside translation.

  7. The joint effect of demographic change on growth and agglomeration

    OpenAIRE

    Theresa Grafeneder-Weissteiner

    2011-01-01

    Recently, there has been wide interest in the "economics" of population aging. Demographic change has crucial consequences for economic behavior; it e.g. implies that consumption and investment decisions vary over the life-cycle. The latter has important implications for economic growth, whereas the former is decisive for the location of economic activity as emphasized in the New Economic Geography (NEG) literature. Both growth and agglomeration processes are, however, themselves interlinked,...

  8. Solid Rocket Booster Large Main and Drogue Parachute Reliability Analysis

    Science.gov (United States)

    Clifford, Courtenay B.; Hengel, John E.

    2009-01-01

    The parachutes on the Space Transportation System (STS) Solid Rocket Booster (SRB) are the means for decelerating the SRB and allowing it to impact the water at a nominal vertical velocity of 75 feet per second. Each SRB has one pilot, one drogue, and three main parachutes. About four minutes after SRB separation, the SRB nose cap is jettisoned, deploying the pilot parachute. The pilot chute then deploys the drogue parachute. The drogue chute provides initial deceleration and proper SRB orientation prior to frustum separation. At frustum separation, the drogue pulls the frustum from the SRB and allows the main parachutes that are mounted in the frustum to unpack and inflate. These chutes are retrieved, inspected, cleaned, repaired as needed, and returned to the flight inventory and reused. Over the course of the Shuttle Program, several improvements have been introduced to the SRB main parachutes. A major change was the replacement of the small (115 ft. diameter) main parachutes with the larger (136 ft. diameter) main parachutes. Other modifications were made to the main parachutes, main parachute support structure, and SRB frustum to eliminate failure mechanisms, improve damage tolerance, and improve deployment and inflation characteristics. This reliability analysis is limited to the examination of the SRB Large Main Parachute (LMP) and drogue parachute failure history to assess the reliability of these chutes. From the inventory analysis, 68 Large Main Parachutes were used in 651 deployments, and 7 chute failures occurred in the 651 deployments. Logistic regression was used to analyze the LMP failure history, and it showed that reliability growth has occurred over the period of use resulting in a current chute reliability of R = .9983. This result was then used to determine the reliability of the 3 LMPs on the SRB, when all must function. There are 29 drogue parachutes that were used in 244 deployments, and no in-flight failures have occurred. Since there are no

  9. 78 FR 38851 - Electric Reliability Organization Proposal To Retire Requirements in Reliability Standards

    Science.gov (United States)

    2013-06-28

    ... either: Provide little protection for Bulk-Power System reliability or are redundant with other aspects... for retirement either: (1) Provide little protection for Bulk-Power System reliability or (2) are... to assure reliability of the Bulk-Power System and should be withdrawn. We have identified 41...

  10. Operational safety reliability research

    International Nuclear Information System (INIS)

    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

  11. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  12. Investment in new product reliability

    International Nuclear Information System (INIS)

    Murthy, D.N.P.; Rausand, M.; Virtanen, S.

    2009-01-01

    Product reliability is of great importance to both manufacturers and customers. Building reliability into a new product is costly, but the consequences of inadequate product reliability can be costlier. This implies that manufacturers need to decide on the optimal investment in new product reliability by achieving a suitable trade-off between the two costs. This paper develops a framework and proposes an approach to help manufacturers decide on the investment in new product reliability.

  13. Structural hybrid reliability index and its convergent solving method based on random–fuzzy–interval reliability model

    Directory of Open Access Journals (Sweden)

    Hai An

    2016-08-01

    Full Text Available Aiming to resolve the problems of a variety of uncertainty variables that coexist in the engineering structure reliability analysis, a new hybrid reliability index to evaluate structural hybrid reliability, based on the random–fuzzy–interval model, is proposed in this article. The convergent solving method is also presented. First, the truncated probability reliability model, the fuzzy random reliability model, and the non-probabilistic interval reliability model are introduced. Then, the new hybrid reliability index definition is presented based on the random–fuzzy–interval model. Furthermore, the calculation flowchart of the hybrid reliability index is presented and it is solved using the modified limit-step length iterative algorithm, which ensures convergence. And the validity of convergent algorithm for the hybrid reliability model is verified through the calculation examples in literature. In the end, a numerical example is demonstrated to show that the hybrid reliability index is applicable for the wear reliability assessment of mechanisms, where truncated random variables, fuzzy random variables, and interval variables coexist. The demonstration also shows the good convergence of the iterative algorithm proposed in this article.

  14. Invasive growth patterns of juvenile nasopharyngeal angiofibroma: radiological imaging and clinical implications.

    Science.gov (United States)

    Szymańska, Anna; Szymański, Marcin; Czekajska-Chehab, Elżbieta; Szczerbo-Trojanowska, Małgorzata

    2014-07-01

    Juvenile nasopharyngeal angiofibroma is a benign lesion with locally aggressive nature. Knowledge of its typical growth patterns is crucial for precise preoperative staging and adequate preoperative patient counseling. This pictorial essay focuses on characteristic radiological features and paths of invasive growth of this rare tumor. Also, the impact of accurate preoperative evaluation of tumor extensions on surgical planning and results of treatment are discussed. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  15. Reliability in engineering '87

    International Nuclear Information System (INIS)

    Tuma, M.

    1987-01-01

    The participants heard 51 papers dealing with the reliability of engineering products. Two of the papers were incorporated in INIS, namely ''Reliability comparison of two designs of low pressure regeneration of the 1000 MW unit at the Temelin nuclear power plant'' and ''Use of probability analysis of reliability in designing nuclear power facilities.''(J.B.)

  16. Revised scoring and improved reliability for the Communication Patterns Questionnaire.

    Science.gov (United States)

    Crenshaw, Alexander O; Christensen, Andrew; Baucom, Donald H; Epstein, Norman B; Baucom, Brian R W

    2017-07-01

    The Communication Patterns Questionnaire (CPQ; Christensen, 1987) is a widely used self-report measure of couple communication behavior and is well validated for assessing the demand/withdraw interaction pattern, which is a robust predictor of poor relationship and individual outcomes (Schrodt, Witt, & Shimkowski, 2014). However, no studies have examined the CPQ's factor structure using analytic techniques sufficient by modern standards, nor have any studies replicated the factor structure using additional samples. Further, the current scoring system uses fewer than half of the total items for its 4 subscales, despite the existence of unused items that have content conceptually consistent with those subscales. These characteristics of the CPQ have likely contributed to findings that subscale scores are often troubled by suboptimal psychometric properties such as low internal reliability (e.g., Christensen, Eldridge, Catta-Preta, Lim, & Santagata, 2006). The present study uses exploratory and confirmatory factor analyses on 4 samples to reexamine the factor structure of the CPQ to improve scale score reliability and to determine if including more items in the subscales is warranted. Results indicate that a 3-factor solution (constructive communication and 2 demand/withdraw scales) provides the best fit for the data. That factor structure was confirmed in the replication samples. Compared with the original scales, the revised scales include additional items that expand the conceptual range of the constructs, substantially improve reliability of scale scores, and demonstrate stronger associations with relationship satisfaction and sensitivity to change in therapy. Implications for research and treatment are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. 18 CFR 39.5 - Reliability Standards.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Reliability Standards... RELIABILITY STANDARDS § 39.5 Reliability Standards. (a) The Electric Reliability Organization shall file each Reliability Standard or modification to a Reliability Standard that it proposes to be made effective under...

  18. Implications of fossil fuel constraints on economic growth and global warming

    International Nuclear Information System (INIS)

    Nel, Willem P.; Cooper, Christopher J.

    2009-01-01

    Energy Security and Global Warming are analysed as 21st century sustainability threats. Best estimates of future energy availability are derived as an Energy Reference Case (ERC). An explicit economic growth model is used to interpret the impact of the ERC on economic growth. The model predicts a divergence from 20th century equilibrium conditions in economic growth and socio-economic welfare is only stabilised under optimistic assumptions that demands a paradigm shift in contemporary economic thought and focused attention from policy makers. Fossil fuel depletion also constrains the maximum extent of Global Warming. Carbon emissions from the ERC comply nominally with the B1 scenario, which is the lowest emissions case considered by the IPCC. The IPCC predicts a temperature response within acceptance limits of the Global Warming debate for the B1 scenario. The carbon feedback cycle, used in the IPCC models, is shown as invalid for low-emissions scenarios and an alternative carbon cycle reduces the temperature response for the ERC considerably compared to the IPCC predictions. Our analysis proposes that the extent of Global Warming may be acceptable and preferable compared to the socio-economic consequences of not exploiting fossil fuel reserves to their full technical potential

  19. 76 FR 66057 - North American Electric Reliability Corporation; Order Approving Regional Reliability Standard

    Science.gov (United States)

    2011-10-25

    ... Reliability Standard that is necessitated by a physical difference in the Bulk-Power System.\\7\\ \\7\\ Order No... Reliability Standards for the Bulk-Power System, Order No. 693, FERC Stats. & Regs. ] 31,242, order on reh'g... electric system event analyses and thereby improve system reliability by promoting improved system design...

  20. Structural hybrid reliability index and its convergent solving method based on random–fuzzy–interval reliability model

    OpenAIRE

    Hai An; Ling Zhou; Hui Sun

    2016-01-01

    Aiming to resolve the problems of a variety of uncertainty variables that coexist in the engineering structure reliability analysis, a new hybrid reliability index to evaluate structural hybrid reliability, based on the random–fuzzy–interval model, is proposed in this article. The convergent solving method is also presented. First, the truncated probability reliability model, the fuzzy random reliability model, and the non-probabilistic interval reliability model are introduced. Then, the new...

  1. Personal growth initiative among Industrial Psychology students in a higher education institution in South Africa

    Directory of Open Access Journals (Sweden)

    Angelique de Jager-van Straaten

    2016-10-01

    Full Text Available Orientation: Personal growth initiative (PGI is an important characteristic of workplace counsellors. Industrial and organisational (I-O psychologists often assist employees with counselling for work-related and personal problems, and therefore PGI is an important research topic for this profession. Research purpose: The purpose of this study was to measure the PGI of I-O psychology students in a higher education institution in South Africa, as well as to explore differences in PGI between demographic groups. Motivation: According to the scope of practice for psychologists, growth and development of employees form part of an I-O psychologist’s responsibilities. PGI is an important characteristic of I-O psychologists as it enables them to efficiently assist employees in growth and development processes. Research design, approach and method: A cross-sectional survey design was used. A purposive non-probability sample (N = 568 of I-O psychology students was taken from a higher education institution in South Africa. A biographical questionnaire and the personal growth initiative scale (PGIS were used as measuring instruments. Main findings: The results indicated that (1 the PGIS is a valid and reliable measure of PGI, (2 PGI is prevalent amongst I-O psychology students and (3 PGI differs between certain demographic groups. Practical implications: The findings of this study will assist in the future development of a training programme for I-O psychology students to equip them with the counselling skills they need to function in a counselling role. Contribution: This study contributes to knowledge regarding the importance of PGI for I-O psychology students. The study will also assist higher education institutes to adapt their training programmes in order to prepare I-O psychology students for their role as counsellors. More knowledge will also be provided with regard to the functioning of the PGIS.

  2. Leptin stimulates aromatase in the growth plate: limiting catch-up growth efficiency.

    Science.gov (United States)

    Masarwi, Majdi; Shamir, Raanan; Phillip, Moshe; Gat-Yablonski, Galia

    2018-06-01

    Catch-up growth (CUG) in childhood is defined as periods of growth acceleration, after the resolution of growth attenuation causes, bringing the children back to their original growth trajectory. Sometimes, however, CUG is incomplete, leading to permanent growth deficit and short stature. The aim of this study was to investigate the mechanisms that limit nutritional-CUG. Specifically, we focused on the crosstalk between leptin, increased by re-feeding, and sex hormones, which increase with age. In vivo studies were performed in young male Sprague Dawley rats fed ad libitum or subjected to 10/36 days of 40% food restriction followed by 90-120 days of re-feeding. In vitro studies were performed on ATDC5 cells. Analyses of mRNA and protein levels were done using qPCR and Western blot, respectively. CUG was complete in body weight and humerus length in animals that were food-restricted for 10 days but not for those food-restricted for 36 days. In vitro studies showed that leptin significantly increased aromatase gene expression and protein level as well as the expression of estrogen and leptin receptors in a dose- and time-dependent manner. The effect of leptin on aromatase was direct and was mediated through the MAPK/Erk, STAT3 and PI3K pathways. The crosstalk between leptin and aromatase in the growth plate suggests that re-feeding during puberty may lead to increased estrogen level and activity, and consequently, irreversible premature epiphyseal growth plate closure. These results may have important implications for the development of novel treatment strategies for short stature in children. © 2018 Society for Endocrinology.

  3. Component reliability analysis for development of component reliability DB of Korean standard NPPs

    International Nuclear Information System (INIS)

    Choi, S. Y.; Han, S. H.; Kim, S. H.

    2002-01-01

    The reliability data of Korean NPP that reflects the plant specific characteristics is necessary for PSA and Risk Informed Application. We have performed a project to develop the component reliability DB and calculate the component reliability such as failure rate and unavailability. We have collected the component operation data and failure/repair data of Korean standard NPPs. We have analyzed failure data by developing a data analysis method which incorporates the domestic data situation. And then we have compared the reliability results with the generic data for the foreign NPPs

  4. How persistent is civilization growth?

    OpenAIRE

    Garrett, Timothy J.

    2011-01-01

    In a recent study (Garrett, 2011), I described theoretical arguments and empirical evidence showing how civilization evolution might be considered from a purely physical basis. One implication is that civilization exhibits the property of persistence in its growth. Here, this argument is elaborated further, and specific near-term forecasts are provided for key economic variables and anthropogenic CO2 emission rates at global scales. Absent some external shock, civilization wealth, energy cons...

  5. Electronics reliability calculation and design

    CERN Document Server

    Dummer, Geoffrey W A; Hiller, N

    1966-01-01

    Electronics Reliability-Calculation and Design provides an introduction to the fundamental concepts of reliability. The increasing complexity of electronic equipment has made problems in designing and manufacturing a reliable product more and more difficult. Specific techniques have been developed that enable designers to integrate reliability into their products, and reliability has become a science in its own right. The book begins with a discussion of basic mathematical and statistical concepts, including arithmetic mean, frequency distribution, median and mode, scatter or dispersion of mea

  6. Mathematical reliability an expository perspective

    CERN Document Server

    Mazzuchi, Thomas; Singpurwalla, Nozer

    2004-01-01

    In this volume consideration was given to more advanced theoretical approaches and novel applications of reliability to ensure that topics having a futuristic impact were specifically included. Topics like finance, forensics, information, and orthopedics, as well as the more traditional reliability topics were purposefully undertaken to make this collection different from the existing books in reliability. The entries have been categorized into seven parts, each emphasizing a theme that seems poised for the future development of reliability as an academic discipline with relevance. The seven parts are networks and systems; recurrent events; information and design; failure rate function and burn-in; software reliability and random environments; reliability in composites and orthopedics, and reliability in finance and forensics. Embedded within the above are some of the other currently active topics such as causality, cascading, exchangeability, expert testimony, hierarchical modeling, optimization and survival...

  7. Effect of morphine on the growth rate of Calliphora stygia (Fabricius) (Diptera: Calliphoridae) and possible implications for forensic entomology.

    Science.gov (United States)

    George, Kelly A; Archer, Melanie S; Green, Lauren M; Conlan, Xavier A; Toop, Tes

    2009-12-15

    Insect specimens collected from decomposing bodies enable forensic entomologists to estimate the minimum post-mortem interval (PMI). Drugs and toxins within a corpse may affect the development rate of insects that feed on them and it is vital to quantify these effects to accurately calculate minimum PMI. This study investigated the effects of morphine on growth rates of the native Australian blowfly, Calliphora stygia (Fabricius) (Diptera: Calliphoridae). Several morphine concentrations were incorporated into pet mince to simulate post-mortem concentrations in morphine, codeine and/or heroin-dosed corpses. There were four treatments for feeding larvae; T 1: control (no morphine); T 2: 2 microg/g morphine; T 3: 10 microg/g morphine; and T 4: 20 microg/g morphine. Ten replicates of 50 larvae were grown at 22 degrees C for each treatment and their development was compared at four comparison intervals; CI 1: 4-day-old larvae; CI 2: 7-day-old larvae; CI 3: pupae; and CI 4: adults. Length and width were measured for larvae and pupae, and costae and tibiae were measured for adults. Additionally, day of pupariation, day of adult eclosion, and survivorship were calculated for each replicate. The continued presence of morphine in meat was qualitatively verified using high-performance liquid chromatography with acidic potassium permanganate chemiluminescence detection. Growth rates of C. stygia fed on morphine-spiked mince did not differ significantly from those fed on control mince for any comparison interval or parameter measured. This suggests that C. stygia is a reliable model to use to accurately age a corpse containing morphine at any of the concentrations investigated.

  8. Evidence that insulin-like growth factor I and growth hormone are required for prostate gland development.

    Science.gov (United States)

    Ruan, W; Powell-Braxton, L; Kopchick, J J; Kleinberg, D L

    1999-05-01

    Insulin-like growth factor I (IGF-I) has been implicated as a factor that may predispose one to prostate cancer. However, no specific relationship between IGF-I and prostate development or cancer in vivo has been established. To determine whether IGF-I was important in prostate development, we examined prostate architecture in IGF-I(-/-) null mice and wild-type littermates. Glands from 44-day-old IGF-I-deficient animals were not only smaller than those from wild-type mice, but also had fewer terminal duct tips and branch points and deficits in tertiary and quaternary branching (P deficit by increasing those parameters of prostate development (P growth as an extension of a normal process.

  9. Changes in East Asian Food Consumption: Some Implications for Australian Irrigated Agriculture

    OpenAIRE

    Philip Taylor; Christopher Findlay

    1996-01-01

    This paper reviews the implications of economic growth for food consumption in Asia, the East Asian supply responses and the determinants of Australian competitiveness in meeting Asian demand from production in Australia. Our special interests are to draw out some implications for Australia’s irrigated agriculture and for the organisation of the export business of that sector of the economy. A key question is the scope for increased exports of fresh rather than processed products. Sources of ...

  10. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated......, and as an example the reliability profile and a sensitivity analyses for a corroded reinforced concrete bridge is shown....

  11. Sociological explanations of economic growth.

    Science.gov (United States)

    Marsh, R M

    1988-01-01

    Even if questions of how resources are distributed within and between societies are the main concern, it is necessary to continue to grapple with the issue of the causes of economic growth since economic growth and level of development continue to be among the most important causes of inequality, poverty, unemployment, and the quality of life. This paper's dependent variable is the economic growth rate of 55 less developed countries (LDCs) over 2 time periods. 1970-78 and 1965-84. The causal model consists of control variables--level of development and domestic investment in 1965--and a variety of independent variables drawn from major sociological theories of economic growth published during the last 3 decades. Multiple regression analysis shows that, net of the effects of the 2 control variables, the variables which have the strongest effect on economic growth are: 1) direct foreign investment, which has a negative effect, 2) the proportion of the population in military service, and 3) the primary school enrollment ratio, both of which have positive effects on economic growth. On the other hand, variables drawn from some theories receive no empirical support. The mass media of communications, ethnolinguistic heterogeneity, democracy and human rights, income inequality, and state-centric theory's key variable, state strength, all fail to show any significant impact on economic growth rates when the control variables and the significant independent variables are held constant. The theoretical implications of these findings are discussed.

  12. Shoot-derived abscisic acid promotes root growth.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J; Ross, John J

    2016-03-01

    The phytohormone abscisic acid (ABA) plays a major role in regulating root growth. Most work to date has investigated the influence of root-sourced ABA on root growth during water stress. Here, we tested whether foliage-derived ABA could be transported to the roots, and whether this foliage-derived ABA had an influence on root growth under well-watered conditions. Using both application studies of deuterium-labelled ABA and reciprocal grafting between wild-type and ABA-biosynthetic mutant plants, we show that both ABA levels in the roots and root growth in representative angiosperms are controlled by ABA synthesized in the leaves rather than sourced from the roots. Foliage-derived ABA was found to promote root growth relative to shoot growth but to inhibit the development of lateral roots. Increased root auxin (IAA) levels in plants with ABA-deficient scions suggest that foliage-derived ABA inhibits root growth through the root growth-inhibitor IAA. These results highlight the physiological and morphological importance, beyond the control of stomata, of foliage-derived ABA. The use of foliar ABA as a signal for root growth has important implications for regulating root to shoot growth under normal conditions and suggests that leaf rather than root hydration is the main signal for regulating plant responses to moisture. © 2015 John Wiley & Sons Ltd.

  13. Reliability of Oronasal Fistula Classification.

    Science.gov (United States)

    Sitzman, Thomas J; Allori, Alexander C; Matic, Damir B; Beals, Stephen P; Fisher, David M; Samson, Thomas D; Marcus, Jeffrey R; Tse, Raymond W

    2018-01-01

    Objective Oronasal fistula is an important complication of cleft palate repair that is frequently used to evaluate surgical quality, yet reliability of fistula classification has never been examined. The objective of this study was to determine the reliability of oronasal fistula classification both within individual surgeons and between multiple surgeons. Design Using intraoral photographs of children with repaired cleft palate, surgeons rated the location of palatal fistulae using the Pittsburgh Fistula Classification System. Intrarater and interrater reliability scores were calculated for each region of the palate. Participants Eight cleft surgeons rated photographs obtained from 29 children. Results Within individual surgeons reliability for each region of the Pittsburgh classification ranged from moderate to almost perfect (κ = .60-.96). By contrast, reliability between surgeons was lower, ranging from fair to substantial (κ = .23-.70). Between-surgeon reliability was lowest for the junction of the soft and hard palates (κ = .23). Within-surgeon and between-surgeon reliability were almost perfect for the more general classification of fistula in the secondary palate (κ = .95 and κ = .83, respectively). Conclusions This is the first reliability study of fistula classification. We show that the Pittsburgh Fistula Classification System is reliable when used by an individual surgeon, but less reliable when used among multiple surgeons. Comparisons of fistula occurrence among surgeons may be subject to less bias if they use the more general classification of "presence or absence of fistula of the secondary palate" rather than the Pittsburgh Fistula Classification System.

  14. Improving machinery reliability

    CERN Document Server

    Bloch, Heinz P

    1998-01-01

    This totally revised, updated and expanded edition provides proven techniques and procedures that extend machinery life, reduce maintenance costs, and achieve optimum machinery reliability. This essential text clearly describes the reliability improvement and failure avoidance steps practiced by best-of-class process plants in the U.S. and Europe.

  15. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific

  16. Role of the placental Vitamin D receptor in modulating feto-placental growth in Fetal growth restriction and Preeclampsia-affected pregnancies.

    Directory of Open Access Journals (Sweden)

    Padma eMurthi

    2016-02-01

    Full Text Available Fetal growth restriction (FGR is a common pregnancy complication that affects up to 5% of pregnancies worldwide. Recent studies demonstrate that Vitamin D deficiency is implicated in reduced fetal growth, which may be rescued by supplementation of Vitamin D. Despite this, the pathway(s by which Vitamin D modulate fetal growth remains to be investigated. Our own studies demonstrate that the Vitamin D receptor (VDR is significantly decreased in placentae from human pregnancies complicated by FGR and contributes to abnormal placental trophoblast apoptosis and differentiation and regulation of cell-cycle genes in vitro. Thus, Vitamin D signalling is important for normal placental function and fetal growth. This review discusses the association of Vitamin D with fetal growth, the function of Vitamin D and its receptor in pregnancy, as well as the functional significance of a placental source of Vitamin D in FGR. Additionally, we propose that for Vitamin D to be clinically effective to prevent and manage FGR, the molecular mechanisms of Vitamin D and its receptor in modulating fetal growth requires further investigation.

  17. The Critical Aspect on Fair Value Accounting And Its Implication To Islamic Financial Institutions.

    Directory of Open Access Journals (Sweden)

    Jamaluddin Majid

    2015-03-01

    Full Text Available The Critical Aspect on Fair Value Accounting And Its Implication To Islamic Financial Institutions. Fair value accounting (FVA paradigm replaced the historical cost accounting (HCA in the development of accounting standards that FVA is more relevant that HCA probably did not provide the real financial and income information. This paper tries to explore critical aspects of the fair value accounting and its implications to Islamic Financial Institutions implications. This study concludes that that fair value accounting measurement provides many critical aspects to be implemented to Islamic Financial Institutions (IFIs. AAOIFI proposed cash equivalent value as respond to fair value measurement that cash equivalent value when the attribute condition are present such as the relevance, reliability and understandability of the resulting information  DOI:10.15408/aiq.v6i2.1236

  18. Matrigel alters the pathophysiology of orthotopic human breast adenocarcinoma xenografts with implications for nanomedicine evaluation.

    Science.gov (United States)

    Shuhendler, Adam J; Prasad, Preethy; Cai, Ping; Hui, Kelvin K W; Henderson, Jeffrey T; Rauth, Andrew M; Wu, Xiao Yu

    2013-08-01

    Matrigel, a mouse sarcoma-derived basement membrane protein mixture, is frequently used to facilitate human tumor xenograft growth in rodents. Despite its known effects on tumor growth and metastasis, its impact on tumor pathophysiology and preclinical evaluation of nanomedicines in tumor xenografts has not been reported previously. Herein bilateral MDA435 tumors were established orthotopically with (Mat+) or without (Mat-) co-injection of Matrigel. Tumor perfusion, morphology and nanoparticle retention were evaluated. As compared to Mat- tumors, Mat+tumors exhibited enhanced vascular perfusion and lymphatic flow, greater blood vessel and lymphatic growth within the tumor core, and more deformation and collapse of lymphatics in tumor-associated lymph nodes. These changes were accompanied by reduced nanoparticle retention in Mat+tumors. The results suggest that Matrigel is not a passive medium for tumor growth, but rather significantly alters long-term tumor architecture. These findings have significant implications for the evaluation of therapeutic nanomedicine in xenograft mouse models. Matrigel is utilized in facilitating human tumor xenograft growth in rodents. The authors demonstrate that Matrigel is not a passive medium for tumor growth; instead it significantly alters long-term tumor architecture, with major implications in the evaluation of therapeutic nanomedicine in xenograft mouse models. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Accuracy and reliability of China's energy statistics

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, Jonathan E.

    2001-09-14

    Many observers have raised doubts about the accuracy and reliability of China's energy statistics, which show an unprecedented decline in recent years, while reported economic growth has remained strong. This paper explores the internal consistency of China's energy statistics from 1990 to 2000, coverage and reporting issues, and the state of the statistical reporting system. Available information suggests that, while energy statistics were probably relatively good in the early 1990s, their quality has declined since the mid-1990s. China's energy statistics should be treated as a starting point for analysis, and explicit judgments regarding ranges of uncertainty should accompany any conclusions.

  20. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...... of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature...... of the uncertainties and their interplay is the developed, step-by-step. The concepts presented are illustrated by numerous examples throughout the text....

  1. The Interrelation among Faithful Representation (Reliability, Corruption and IFRS Adoption: An Empirical Investigation

    Directory of Open Access Journals (Sweden)

    Alexios Kythreotis

    2015-08-01

    Full Text Available Purpose – The degree of corruption, among other things, indicates the non -implementation of laws, weak enforcement of legal sanctions and the existence of non-transparent economic transactions. Therefore, the expected change in reliability (faithful-representation resulting from the adoption of IAS/IFRS, does not depend solely on the adoption of IAS/IFRS but is also influenced by the degree of corruption in each country. The purpose of this paper is to examine whether the above statement is true. Design/methodology/approach – The data were taken from DataStream database and the sample period consists of listed companies of fifteen European countries that adopted IAS/IFRS mandatorily. The time horizon is 10 years, from 2000 until 2009. The period between 2000 and 2004 is defined as the period before the adoption, while the period between 2005 and 2009 is defined as the period after the adoption. The reliability/faithful representation of financial statements - as defined by the Conceptual Framework - is detected through regression analysis. Findings – The findings advocate that the adoption of IFRS/IAS seems to be not enough. It appears that the level of reliability of financial statements in every country does not depend solely on the adoption of IAS/IFRS but is also influenced by the degree of corruption in each country. Research limitations/implications – The models that are used for the measurement of reliability have as an independent variable the short-term accruals. Given that, the models fail to take into consideration accounting treatments that concern non-current assets/liabilities. Originality/value – The findings that are identified for counties with a high degree of corruption indicate a statistically significant reduction in reliability after the adoption of IAS/IFRS. These findings constitute a useful tool for the IASB and the European Commission as well as for the users of financial statements.

  2. Advances in developing rapid, reliable and portable detection systems for alcohol.

    Science.gov (United States)

    Thungon, Phurpa Dema; Kakoti, Ankana; Ngashangva, Lightson; Goswami, Pranab

    2017-11-15

    Development of portable, reliable, sensitive, simple, and inexpensive detection system for alcohol has been an instinctive demand not only in traditional brewing, pharmaceutical, food and clinical industries but also in rapidly growing alcohol based fuel industries. Highly sensitive, selective, and reliable alcohol detections are currently amenable typically through the sophisticated instrument based analyses confined mostly to the state-of-art analytical laboratory facilities. With the growing demand of rapid and reliable alcohol detection systems, an all-round attempt has been made over the past decade encompassing various disciplines from basic and engineering sciences. Of late, the research for developing small-scale portable alcohol detection system has been accelerated with the advent of emerging miniaturization techniques, advanced materials and sensing platforms such as lab-on-chip, lab-on-CD, lab-on-paper etc. With these new inter-disciplinary approaches along with the support from the parallel knowledge growth on rapid detection systems being pursued for various targets, the progress on translating the proof-of-concepts to commercially viable and environment friendly portable alcohol detection systems is gaining pace. Here, we summarize the progress made over the years on the alcohol detection systems, with a focus on recent advancement towards developing portable, simple and efficient alcohol sensors. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Catalan family companies with high growth during the crisis period

    Directory of Open Access Journals (Sweden)

    Nuria Arimany-Serrat

    2016-11-01

    Full Text Available Purpose: This study aims to analyze the financial and economic health of the Catalan family companies with high growth during the crisis period (2008-2013, as an engine of job creation and economic development of the territory, identifying the economic and financial characteristics. Design/methodology/approach: The data used comes from the financial statements of the high growth Catalan companies during the crisis period of 2008-2013, in particular it collects a sample of the 140 high growth Catalan companies where a 70% of them are family businesses, there is a financial and economic analysis using descriptive statistics of these family businesses with a regression model to achieve results and conclusions. Findings: During the 2008-2013 crisis, Catalan family companies with high growth that are mostly small businesses have a good economic and financial health, with moderate innovation and a great potential for survival. Research limitations/implications: It would be convenient to make the same study in similar territories where most of the companies are family businesses, in order to compare the financial and economic analysis, valuing the impact of these companies in the business. Practical implications: It allows valuing the projection of these kinds of family companies, mostly in Catalonia, in a financial and economic level, identifying if they have a proper financial strategy. Social implications: The results show that these companies have great financial and economic health and have a better response during a crisis period. Originality / value: The study shows that family businesses have moderate indebtedness and acceptable rendibility in the crisis period, although, since they are small businesses the lack of innovation and patents can lead to future problems.

  4. Formal-informal economy linkages: What implications for poverty in ...

    African Journals Online (AJOL)

    The findings have implications for poverty analysis in South Africa. Policy which views poverty as being located outside the mainstream of the economy – in the so-called 'second' economy – is misleading. Instead, an integrated approach which views poverty as linked to and a product of the trajectory and growth patterns of ...

  5. Growth curves and their implications in hand-fed Monk parrots (Myiopsitta monachus

    Directory of Open Access Journals (Sweden)

    Petzinger C

    2015-10-01

    Full Text Available Christina Petzinger,1,2 J Jill Heatley,3 John E Bauer1,2 1Comparative Animal Nutrition Research Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, 2Intercollegiate Faculty of Nutrition, Texas A&M University, 3Zoological Medicine Service, Department of Small Animal Medicine and Surgery, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA Abstract: Monk parrots (Myiopsitta monachus were hand-fed over two chick seasons spanning of 2010 to 2011. Information from the growth curve of chicks hand-fed in 2010 was used to develop a feeding protocol for the 2011 season (Protocol-2011. This protocol addressed the problems of delayed followed by excessive growth experienced by parrots hand fed in 2010. Monk parrots that were hand-fed in 2011 following the new protocol experienced delayed growth after 20 days of age. However, some Monk parrots were fed in excess of Protocol-2011 and did not experience a major delay in growth. The energy requirement equations used to construct Protocol-2011 were low when compared to adult Monk parrot maintenance energy requirements. The data suggest that growing birds do not require approximately twice their adult maintenance energy requirements, as is the case for growing dogs. Additionally, there appear to be fluctuations in energy needs as Monk parrots grow. A major increase in energy needs occurred between days 18 and 23 posthatching, which corresponds to feather development and growth in Monk parrot chicks. Thus, multiple equations estimating energy requirements, rather than just one equation, are likely needed from hatching to fledging in order to ensure adequate energy is provided to chicks. More research on the energy requirements of growing Monk parrots, especially around the time of fledging and weaning, is needed to improve hand-fed methods and potentially the adult health of hand-fed birds. Keywords

  6. Expression of hepatocyte growth factor and the proto-oncogenic receptor c-Met in canine osteosarcoma

    NARCIS (Netherlands)

    Fieten, H; Spee, B; Ijzer, J; Kik, M J; Penning, L C; Kirpensteijn, J

    Hepatocyte growth factor (HGF) and the proto-oncogenic receptor c-Met are implicated in growth, invasion, and metastasis in human cancer. Little information is available on the expression and role of both gene products in canine osteosarcoma. We hypothesized that the expression of c-Met is

  7. Influence of reliability of the relay protection to the whole reliability of electric power systems

    International Nuclear Information System (INIS)

    Stojanovski, Ljupcho I.

    2001-01-01

    The influence of the reliability of the elements of relay protection up today analyses of the reliability on electric power systems, very rare has been taken into consideration, in other words, in these analyses it is assumed that the reliability of the protection has value one. In this work an attempt is that through modelling of individual types of protection of the elements of high-voltage systems to make calculation to the influence of the reliability of the relay protection on the total reliability of the high-voltage systems.(Author)

  8. Bistable Bacterial Growth Rate in Response to Antibiotics with Low Membrane Permeability

    Science.gov (United States)

    Elf, Johan; Nilsson, Karin; Tenson, Tanel; Ehrenberg, Måns

    2006-12-01

    We demonstrate that growth rate bistability for bacterial cells growing exponentially at a fixed external antibiotic concentration can emerge when the cell wall permeability for the drug is low and the growth rate sensitivity to the intracellular drug concentration is high. Under such conditions, an initially high growth rate can remain high, due to dilution of the intracellular drug concentration by rapid cell volume increase, while an initially low growth rate can remain low, due to slow cell volume increase and insignificant drug dilution. Our findings have implications for the testing of novel antibiotics on growing bacterial strains.

  9. Reliability of tonosafe disposable tonometer prisms: clinical implications from the Veterans Affairs Boston Healthcare System Quality Assurance Study.

    Science.gov (United States)

    Thomas, V; Daly, M K; Cakiner-Egilmez, T; Baker, E

    2011-05-01

    Given the Veterans Affairs Boston Healthcare System's recent introduction of single-use Tonosafe disposable tonometer prisms as an alternative to Goldmann applanation tonometers (GATs), this study had two aims: to conduct a large-scale quality assurance trial to assess the reliability of intraocular pressure (IOP) measurements of the Tonosafe disposable tonometer compared with GAT, particularly at extremes of pressure; to evaluate the suitability of Tonosafe disposable tonometer prisms as an acceptable substitute for GATs and for clinic-wide implementation in an academic tertiary referral setting. Ophthalmology resident physicians measured the IOPs of patients in general and specialty eye clinics with the Tonosafe disposable tonometer and GAT. Tonosafe test-retest reliability data were also collected. A retrospective review of patient charts and data analysis were performed to determine the reliability of measurements. The IOPs of 652 eyes (326 patients) were measured with both GAT and Tonosafe, with a range of 3-34 mm Hg. Linear regression analysis showed R=0.93, slope=0.91, both of which supported the proposed hypothesis, and the y-intercept=-1.05 was significantly different from the hypothesized value. The Tonosafe test-retest repeatability (40 eyes of 40 patients), r=0.977, was very high, which was further supported by linear regression slope=0.993, y-intercept=0.118, and a Tonosafe repeatability coefficient of 2.06, similar to GAT repeatability. The IOP measurements by Tonosafe disposable prisms correlated closely with Goldmann measurements, with similar repeated measurement variability to GAT. This suggests that the Tonosafe is an acceptable substitute for GAT to measure IOP in ophthalmology clinic settings.

  10. The Arabidopsis transcription factor ABIG1 relays ABA signaled growth inhibition and drought induced senescence.

    Science.gov (United States)

    Liu, Tie; Longhurst, Adam D; Talavera-Rauh, Franklin; Hokin, Samuel A; Barton, M Kathryn

    2016-10-04

    Drought inhibits plant growth and can also induce premature senescence. Here we identify a transcription factor, ABA INSENSITIVE GROWTH 1 (ABIG1) required for abscisic acid (ABA) mediated growth inhibition, but not for stomatal closure. ABIG1 mRNA levels are increased both in response to drought and in response to ABA treatment. When treated with ABA, abig1 mutants remain greener and produce more leaves than comparable wild-type plants. When challenged with drought, abig1 mutants have fewer yellow, senesced leaves than wild-type. Induction of ABIG1 transcription mimics ABA treatment and regulates a set of genes implicated in stress responses. We propose a model in which drought acts through ABA to increase ABIG1 transcription which in turn restricts new shoot growth and promotes leaf senescence. The results have implications for plant breeding: the existence of a mutant that is both ABA resistant and drought resistant points to new strategies for isolating drought resistant genetic varieties.

  11. Macromolecular Crystal Growth by Means of Microfluidics

    Science.gov (United States)

    vanderWoerd, Mark; Ferree, Darren; Spearing, Scott; Monaco, Lisa; Molho, Josh; Spaid, Michael; Brasseur, Mike; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    We have performed a feasibility study in which we show that chip-based, microfluidic (LabChip(TM)) technology is suitable for protein crystal growth. This technology allows for accurate and reliable dispensing and mixing of very small volumes while minimizing bubble formation in the crystallization mixture. The amount of (protein) solution remaining after completion of an experiment is minimal, which makes this technique efficient and attractive for use with proteins, which are difficult or expensive to obtain. The nature of LabChip(TM) technology renders it highly amenable to automation. Protein crystals obtained in our initial feasibility studies were of excellent quality as determined by X-ray diffraction. Subsequent to the feasibility study, we designed and produced the first LabChip(TM) device specifically for protein crystallization in batch mode. It can reliably dispense and mix from a range of solution constituents into two independent growth wells. We are currently testing this design to prove its efficacy for protein crystallization optimization experiments. In the near future we will expand our design to incorporate up to 10 growth wells per LabChip(TM) device. Upon completion, additional crystallization techniques such as vapor diffusion and liquid-liquid diffusion will be accommodated. Macromolecular crystallization using microfluidic technology is envisioned as a fully automated system, which will use the 'tele-science' concept of remote operation and will be developed into a research facility for the International Space Station as well as on the ground.

  12. The rating reliability calculator

    Directory of Open Access Journals (Sweden)

    Solomon David J

    2004-04-01

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

  13. Reliability Assessment Of Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2014-01-01

    Reduction of cost of energy for wind turbines are very important in order to make wind energy competitive compared to other energy sources. Therefore the turbine components should be designed to have sufficient reliability but also not be too costly (and safe). This paper presents models...... for uncertainty modeling and reliability assessment of especially the structural components such as tower, blades, substructure and foundation. But since the function of a wind turbine is highly dependent on many electrical and mechanical components as well as a control system also reliability aspects...... of these components are discussed and it is described how there reliability influences the reliability of the structural components. Two illustrative examples are presented considering uncertainty modeling, reliability assessment and calibration of partial safety factors for structural wind turbine components exposed...

  14. Reliability: How much is it worth? Beyond its estimation or prediction, the (net) present value of reliability

    International Nuclear Information System (INIS)

    Saleh, J.H.; Marais, K.

    2006-01-01

    In this article, we link an engineering concept, reliability, to a financial and managerial concept, net present value, by exploring the impact of a system's reliability on its revenue generation capability. The framework here developed for non-repairable systems quantitatively captures the value of reliability from a financial standpoint. We show that traditional present value calculations of engineering systems do not account for system reliability, thus over-estimate a system's worth and can therefore lead to flawed investment decisions. It is therefore important to involve reliability engineers upfront before investment decisions are made in technical systems. In addition, the analyses here developed help designers identify the optimal level of reliability that maximizes a system's net present value-the financial value reliability provides to the system minus the cost to achieve this level of reliability. Although we recognize that there are numerous considerations driving the specification of an engineering system's reliability, we contend that the financial analysis of reliability here developed should be made available to decision-makers to support in part, or at least be factored into, the system reliability specification

  15. Building and integrating reliability models in a Reliability-Centered-Maintenance approach

    International Nuclear Information System (INIS)

    Verite, B.; Villain, B.; Venturini, V.; Hugonnard, S.; Bryla, P.

    1998-03-01

    Electricite de France (EDF) has recently developed its OMF-Structures method, designed to optimize preventive maintenance of passive structures such as pipes and support, based on risk. In particular, reliability performances of components need to be determined; it is a two-step process, consisting of a qualitative sort followed by a quantitative evaluation, involving two types of models. Initially, degradation models are widely used to exclude some components from the field of preventive maintenance. The reliability of the remaining components is then evaluated by means of quantitative reliability models. The results are then included in a risk indicator that is used to directly optimize preventive maintenance tasks. (author)

  16. Growth mindset tempers the effects of poverty on academic achievement

    OpenAIRE

    Claro, Susana; Paunesku, David; Dweck, Carol S.

    2016-01-01

    This study is the first, to our knowledge, to show that a growth mindset (the belief that intelligence is not fixed and can be developed) reliably predicts achievement across a national sample of students, including virtually all of the schools and socioeconomic strata in Chile. It also explores the relationship between income and mindset for the first time, to our knowledge, finding that students from lower-income families were less likely to hold a growth mindset than their wealthier peers ...

  17. Multidisciplinary System Reliability Analysis

    Science.gov (United States)

    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.

  18. Meniscus Shapes in Detached Bridgman Growth

    Science.gov (United States)

    Volz, M. P.; Mazuruk, K

    2010-01-01

    In detached Bridgman crystal growth, most of the melt is in contact with the ampoule wall, but the crystal is separated from the wall by a small gap, typically 1-100 micrometers. A liquid free surface, or meniscus, bridges across this gap at the position of the melt-crystal interface. Meniscus shapes have been calculated for the case of detached Bridgman growth in cylindrical ampoules by solving the Young-Laplace equation. Key parameters affecting meniscus shapes are the growth angle, contact angle of the meniscus to the ampoule wall, the pressure differential across the meniscus, and the Bond number, a measure of the ratio of gravitational to capillary forces. In general, for specified values of growth and contact angles, solutions exist only over a finite range of pressure differentials. For intermediate values of the Bond number, there are multiple solutions to the Young-Laplace equations. There are also cases where, as a function of pressure differential, existence intervals alternate with intervals where no solutions exist. The implications of the meniscus shape calculations on meniscus stability are discussed.

  19. Reliability-based optimization of maintenance scheduling of mechanical components under fatigue

    Science.gov (United States)

    Beaurepaire, P.; Valdebenito, M.A.; Schuëller, G.I.; Jensen, H.A.

    2012-01-01

    This study presents the optimization of the maintenance scheduling of mechanical components under fatigue loading. The cracks of damaged structures may be detected during non-destructive inspection and subsequently repaired. Fatigue crack initiation and growth show inherent variability, and as well the outcome of inspection activities. The problem is addressed under the framework of reliability based optimization. The initiation and propagation of fatigue cracks are efficiently modeled using cohesive zone elements. The applicability of the method is demonstrated by a numerical example, which involves a plate with two holes subject to alternating stress. PMID:23564979

  20. Micromechanisms of fracture and fatigue in Ti3Al based and TiAl based intermetallics

    International Nuclear Information System (INIS)

    James, A.W.; Chave, R.A.; Hippsley, C.A.; Bowen, P.

    1993-01-01

    Micromechanisms of fracture and fatigue crack growth resistance in specific Ti 3 Al based and TiAl based intermetallics are reviewed. Effects of test temperature, environment and microstructure on crack growth resistance are considered in detail for several Ti 3 Al and Ti'Al based intermetallic systems under development. The implications of these studies for the structural reliability of these materials is also addressed briefly. (orig.)

  1. Implications of foreign direct investment in India's retail sector

    Directory of Open Access Journals (Sweden)

    Murali Patibandla

    2014-12-01

    Full Text Available Supply chain is the backbone of retail business. Adoption of an efficient supply chain between producers and consumers by modern large retailers could reduce average transaction and information costs of market exchange; generate surplus for stakeholders such as producers, farmers, and consumers; expand output; and could thereby contribute to economic growth and net employment gains. Foreign players can introduce a highly advanced supply chain and develop local producers and generate externalities. This paper develops a simple theory of supply chain and economic growth. It shows the implications of adaptation of the Wal-Mart model of retailing on India's retail business.

  2. Implications of agricultural transitions and urbanization for ecosystem services.

    Science.gov (United States)

    Cumming, Graeme S; Buerkert, Andreas; Hoffmann, Ellen M; Schlecht, Eva; von Cramon-Taubadel, Stephan; Tscharntke, Teja

    2014-11-06

    Historically, farmers and hunter-gatherers relied directly on ecosystem services, which they both exploited and enjoyed. Urban populations still rely on ecosystems, but prioritize non-ecosystem services (socioeconomic). Population growth and densification increase the scale and change the nature of both ecosystem- and non-ecosystem-service supply and demand, weakening direct feedbacks between ecosystems and societies and potentially pushing social-ecological systems into traps that can lead to collapse. The interacting and mutually reinforcing processes of technological change, population growth and urbanization contribute to over-exploitation of ecosystems through complex feedbacks that have important implications for sustainable resource use.

  3. Endoplasmic reticulum stress disrupts placental morphogenesis: implications for human intrauterine growth restriction.

    Science.gov (United States)

    Yung, Hong Wa; Hemberger, Myriam; Watson, Erica D; Senner, Claire E; Jones, Carolyn P; Kaufman, Randal J; Charnock-Jones, D Stephen; Burton, Graham J

    2012-12-01

    We recently reported the first evidence of placental endoplasmic reticulum (ER) stress in the pathophysiology of human intrauterine growth restriction. Here, we used a mouse model to investigate potential underlying mechanisms. Eif2s1(tm1RjK) mice, in which Ser51 of eukaryotic initiation factor 2 subunit alpha (eIF2α) is mutated, display a 30% increase in basal translation. In Eif2s1(tm1RjK) placentas, we observed increased ER stress and anomalous accumulation of glycoproteins in the endocrine junctional zone (Jz), but not in the labyrinthine zone where physiological exchange occurs. Placental and fetal weights were reduced by 15% (97 mg to 82 mg, p growth factor for placental development; indeed, activity in the Pdk1-Akt-mTOR pathways was decreased in Eif2s1(tm1RjK) placentas, indicating loss of Igf2 signalling. Furthermore, we observed premature differentiation of trophoblast progenitors at E9.5 in mutant placentas, consistent with the in vitro results and with the disproportionate development of the labyrinth and Jz seen in placentas at E18.5. Similar disproportion has been reported in the Igf2-null mouse. These results demonstrate that ER stress adversely affects placental development, and that modulation of post-translational processing, and hence bioactivity, of secreted growth factors contributes to this effect. Placental dysmorphogenesis potentially affects fetal growth through reduced exchange capacity. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  4. Assessing the reliability and validity of anti-tobacco attitudes/beliefs in the context of a campaign strategy.

    Science.gov (United States)

    Arheart, Kristopher L; Sly, David F; Trapido, Edward J; Rodriguez, Richard D; Ellestad, Amy J

    2004-11-01

    To identify multi-item attitude/belief scales associated with the theoretical foundations of an anti-tobacco counter-marketing campaign and assess their reliability and validity. The data analyzed are from two state-wide, random, cross-sectional telephone surveys [n(S1)=1,079, n(S2)=1,150]. Items forming attitude/belief scales are identified using factor analysis. Reliability is assessed with Chronbach's alpha. Relationships among scales are explored using Pearson correlation. Validity is assessed by testing associations derived from the Centers for Disease Control and Prevention's (CDC) logic model for tobacco control program development and evaluation linking media exposure to attitudes/beliefs, and attitudes/beliefs to smoking-related behaviors. Adjusted odds ratios are employed for these analyses. Three factors emerged: traditional attitudes/beliefs about tobacco and tobacco use, tobacco industry manipulation and anti-tobacco empowerment. Reliability coefficients are in the range of 0.70 and vary little between age groups. The factors are correlated with one-another as hypothesized. Associations between media exposure and the attitude/belief scales and between these scales and behaviors are consistent with the CDC logic model. Using reliable, valid multi-item scales is theoretically and methodologically more sound than employing single-item measures of attitudes/beliefs. Methodological, theoretical and practical implications are discussed.

  5. Arid1b haploinsufficient mice reveal neuropsychiatric phenotypes and reversible causes of growth impairment.

    Science.gov (United States)

    Celen, Cemre; Chuang, Jen-Chieh; Luo, Xin; Nijem, Nadine; Walker, Angela K; Chen, Fei; Zhang, Shuyuan; Chung, Andrew S; Nguyen, Liem H; Nassour, Ibrahim; Budhipramono, Albert; Sun, Xuxu; Bok, Levinus A; McEntagart, Meriel; Gevers, Evelien F; Birnbaum, Shari G; Eisch, Amelia J; Powell, Craig M; Ge, Woo-Ping; Santen, Gijs We; Chahrour, Maria; Zhu, Hao

    2017-07-11

    Sequencing studies have implicated haploinsufficiency of ARID1B , a SWI/SNF chromatin-remodeling subunit, in short stature (Yu et al., 2015), autism spectrum disorder (O'Roak et al., 2012), intellectual disability (Deciphering Developmental Disorders Study, 2015), and corpus callosum agenesis (Halgren et al., 2012). In addition, ARID1B is the most common cause of Coffin-Siris syndrome, a developmental delay syndrome characterized by some of the above abnormalities (Santen et al., 2012; Tsurusaki et al., 2012; Wieczorek et al., 2013). We generated Arid1b heterozygous mice, which showed social behavior impairment, altered vocalization, anxiety-like behavior, neuroanatomical abnormalities, and growth impairment. In the brain, Arid1b haploinsufficiency resulted in changes in the expression of SWI/SNF-regulated genes implicated in neuropsychiatric disorders. A focus on reversible mechanisms identified Insulin-like growth factor (IGF1) deficiency with inadequate compensation by Growth hormone-releasing hormone (GHRH) and Growth hormone (GH), underappreciated findings in ARID1B patients. Therapeutically, GH supplementation was able to correct growth retardation and muscle weakness. This model functionally validates the involvement of ARID1B in human disorders, and allows mechanistic dissection of neurodevelopmental diseases linked to chromatin-remodeling.

  6. International labour migration in the Asian-Pacific region: patterns, policies and economic implications.

    Science.gov (United States)

    Athukorala, P

    1993-11-01

    "This paper reviews the literature on international labour migration from and within the Asian-Pacific region. It deals with patterns and characteristics of migration flows, government policies towards labour migration, and economic implications of labour migration for both labour-exporting and importing countries in the region. The indications are that, despite gradual slowing down of labour flows to the western industrial countries and the Middle East, labour migration will continue to be a major economic influence on surplus-labour countries in the region. As an integral part of the growth dynamism in the region, labour migration has now begun to take on a regional dimension, with immense implications for the process of industrial restructuring in high growth economies and the changing pattern of economic interdependence among countries." excerpt

  7. Calculating system reliability with SRFYDO

    Energy Technology Data Exchange (ETDEWEB)

    Morzinski, Jerome [Los Alamos National Laboratory; Anderson - Cook, Christine M [Los Alamos National Laboratory; Klamann, Richard M [Los Alamos National Laboratory

    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.

  8. Franchised fast food brands: An empirical study of factors influencing growth

    Directory of Open Access Journals (Sweden)

    Christopher A. Wingrove

    2017-03-01

    Full Text Available Orientation: Franchising is a popular and multifaceted business arrangement that captures a sizeable portion of the restaurant industry worldwide. Research purpose: The study empirically investigated the influence of various site location and branding factors on the growth of franchised fast food restaurant brands across the greater Gauteng region. Motivation of the study: Researching which factors influence the growth of franchised fast food restaurant brands is important for an emerging market context such as South Africa when considering the marked increase in the consumption of fast foods. Design: A sample of 140 customers was surveyed from 12 leading franchised fast food outlets. Primary data were collected for various items representing site location and brand factors. Regression analysis was used to test the hypotheses. Findings: The overall findings showed that convenience and central facilities of a retail location are positively and significantly associated with the growth of the franchise fast food outlet. Practical implications: The study findings have implications for practitioners who need to take into account which factors influence revenue growth, since targeted interventions may be required to implement sustainable strategies by franchisors. Contribution: The findings may serve as a catalyst for this growing and important activity in South Africa and other emerging markets.

  9. The influence of IVF/ICSI treatment on human embryonic growth trajectories.

    Science.gov (United States)

    Eindhoven, S C; van Uitert, E M; Laven, J S E; Willemsen, S P; Koning, A H J; Eilers, P H C; Exalto, N; Steegers, E A P; Steegers-Theunissen, R P M

    2014-12-01

    Is in vitro fertilization treatment with or without intracytoplasmatic sperm injection (IVF/ICSI) associated with changes in first and second trimester embryonic and fetal growth trajectories and birthweight in singleton pregnancies? Embryonic and fetal growth trajectories and birthweight are not significantly different between pregnancies conceived with IVF/ICSI treatment and spontaneously conceived pregnancies with reliable pregnancy dating. IVF/ICSI treatment has been associated with increased risks of preterm birth, fetal growth restriction and low birthweight. Decreased first-trimester crown-rump length (CRL) in the general population has been inversely associated with the same adverse pregnancy outcomes. In a prospective periconception birth cohort study conducted in a tertiary centre, 146 singleton pregnancies with reliable pregnancy dating and nonmalformed live borns were investigated, comprised of 88 spontaneous and 58 IVF/ICSI pregnancies. Serial 3D ultrasound scans were performed from 6 to 12 weeks of gestation. As estimates of embryonic growth, CRL and embryonic volume (EV) were measured using the I-Space virtual reality system. General characteristics were obtained from self-administered questionnaires at enrolment. Fetal growth parameters at 20 weeks and birthweight were obtained from medical records. To assess associations between IVF/ICSI and embryonic growth trajectories, estimated fetal weight and birthweight, stepwise linear mixed model analyses and linear regression analyses were performed using square root transformed CRL and fourth root transformed EV. In 146 pregnancies, 934 ultrasound scans were performed of which 849 (90.9%) CRLs and 549 (58.8%) EVs could be measured. Embryonic growth trajectories were comparable between IVF/ICSI pregnancies and spontaneously conceived pregnancies (CRL: βIVF/ICSI = 0.10√mm; P = 0.10; EV: βIVF/ICSI = 0.03(4)√cm³; P = 0.13). Estimated fetal weight and birthweight were also comparable between both

  10. Deconstructing the BRICs : Structural Transformation and Aggregate Productivity Growth

    NARCIS (Netherlands)

    de Vries, Gaaitzen; Erumban, A. A.; Timmer, M.P.; Voskoboynikov, I.; Wu H.X., [No Value

    2011-01-01

    This paper studies structural transformation and its implications for productivity growth in the BRIC countries based on a new database that provides trends in value added and employment at a detailed 35-sector level. We find that for China, India and Russia reallocation of labour across sectors is

  11. Semantic growth of morphological families in English

    Directory of Open Access Journals (Sweden)

    Henry Regina

    2013-01-01

    Full Text Available This paper explores the question of when and how morphological families are formed in one’s mental lexicon, by analyzing age-of-acquisition norms to morphological families (e.g., booking, bookshelf, check book and their shared morphemes (book. We demonstrate that the speed of growth and the size of the family depend on how early the shared morpheme is acquired and how many connections the family has at the time a new concept is incorporated in the family. These findings dovetail perfectly with the Semantic Growth model of connectivity in semantic networks by Steyvers and Tenenbaum (2005. We discuss implications of our findings for theories of vocabulary acquisition.

  12. Effect of an Extract from Saprozoic Nematode-Infested Compost on the Mycelial Growth of Agaricus brunnescens

    OpenAIRE

    Kaufman, T. D.; Bloom, J. R.; Lukezic, F. L.

    1983-01-01

    Extracts from compost infested with Caenorhabditis elegans suppressed mycelial growth of Agaricus brunnescens. An extract from uninfested compost also inhibited mycelial growth but to a lesser degree. The critical role of compost bacteria and/or other compost micro-organisms is implicated by these results.

  13. Inhomogeneous microstructural growth by irradiation

    DEFF Research Database (Denmark)

    Krishan, K.; Singh, Bachu Narain; Leffers, Torben

    1985-01-01

    In the present paper we discuss the development of heterogeneous microstructure for uniform irradiation conditions. It is shown that microstructural inhomogeneities on a scale of 0.1 μm can develop purely from kinematic considerations because of the basic structure of the rate equations used...... to describe such evolution. Two aspects of the growth of such inhomogeneities are discussed. Firstly, it is shown that a local variation in the sink densities of the various microstructural defects will tend to enhance the inhomogeneity rather than remove it. Secondly, such inhomogeneities will lead to point...... defect fluxes that result in a spatial growth of the inhomogeneous region, which will be stopped only when the microstructural density around this region becomes large. The results have important implications in the formation of denuded zones and void formation in metals....

  14. Robust Reliability or reliable robustness? - Integrated consideration of robustness and reliability aspects

    DEFF Research Database (Denmark)

    Kemmler, S.; Eifler, Tobias; Bertsche, B.

    2015-01-01

    products are and vice versa. For a comprehensive understanding and to use existing synergies between both domains, this paper discusses the basic principles of Reliability- and Robust Design theory. The development of a comprehensive model will enable an integrated consideration of both domains...

  15. Field reliability of electronic systems

    International Nuclear Information System (INIS)

    Elm, T.

    1984-02-01

    This report investigates, through several examples from the field, the reliability of electronic units in a broader sense. That is, it treats not just random parts failure, but also inadequate reliability design and (externally and internally) induced failures. The report is not meant to be merely an indication of the state of the art for the reliability prediction methods we know, but also as a contribution to the investigation of man-machine interplay in the operation and repair of electronic equipment. The report firmly links electronics reliability to safety and risk analyses approaches with a broader, system oriented view of reliability prediction and with postfailure stress analysis. It is intended to reveal, in a qualitative manner, the existence of symptom and cause patterns. It provides a background for further investigations to identify the detailed mechanisms of the faults and the remedical actions and precautions for achieving cost effective reliability. (author)

  16. Step-driven surface segregation and ordering during Si-Ge MBE growth

    International Nuclear Information System (INIS)

    Jesson, D.E.; Pennycook, S.J.; Baribeau, J.M.; Houghton, D.C.

    1992-06-01

    An important role of type S B step edges in determining the as-grown microstructure of Si-Ge superlattices and alloys is implicated from direct Z-contrast images of as-grown structures. A variety of different ordered phase variants can arise at each Si on Ge interface as a result of vertical segregation during superlattice growth. A new monoclinic-ordered structure is predicted to arise as a result of lateral segregation during alloy growth

  17. Domain requirements for the Dock adapter protein in growth- cone signaling

    OpenAIRE

    Rao, Yong; Zipursky, S. Lawrence

    1998-01-01

    Tyrosine phosphorylation has been implicated in growth-cone guidance through genetic, biochemical, and pharmacological studies. Adapter proteins containing src homology 2 (SH2) domains and src homology 3 (SH3) domains provide a means of linking guidance signaling through phosphotyrosine to downstream effectors regulating growth-cone motility. The Drosophila adapter, Dreadlocks (Dock), the homolog of mammalian Nck containing three N-terminal SH3 domains and a single SH2 domain, is highly speci...

  18. Safety and reliability criteria

    International Nuclear Information System (INIS)

    O'Neil, R.

    1978-01-01

    Nuclear power plants and, in particular, reactor pressure boundary components have unique reliability requirements, in that usually no significant redundancy is possible, and a single failure can give rise to possible widespread core damage and fission product release. Reliability may be required for availability or safety reasons, but in the case of the pressure boundary and certain other systems safety may dominate. Possible Safety and Reliability (S and R) criteria are proposed which would produce acceptable reactor design. Without some S and R requirement the designer has no way of knowing how far he must go in analysing his system or component, or whether his proposed solution is likely to gain acceptance. The paper shows how reliability targets for given components and systems can be individually considered against the derived S and R criteria at the design and construction stage. Since in the case of nuclear pressure boundary components there is often very little direct experience on which to base reliability studies, relevant non-nuclear experience is examined. (author)

  19. Proposed reliability cost model

    Science.gov (United States)

    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.

  20. Reliability-Based Optimization in Structural Engineering

    DEFF Research Database (Denmark)

    Enevoldsen, I.; Sørensen, John Dalsgaard

    1994-01-01

    In this paper reliability-based optimization problems in structural engineering are formulated on the basis of the classical decision theory. Several formulations are presented: Reliability-based optimal design of structural systems with component or systems reliability constraints, reliability...

  1. Software reliability models for critical applications

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Software reliability models for critical applications

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. French power system reliability report 2008

    International Nuclear Information System (INIS)

    Tesseron, J.M.

    2009-06-01

    The reliability of the French power system was fully under control in 2008, despite the power outage in the eastern part of the Provence-Alpes-Cote d'Azur region on November 3, which had been dreaded for several years, since it had not been possible to set up a structurally adequate network. Pursuant to a consultation meeting, the reinforcement solution proposed by RTE was approved by the Minister of Energy, boding well for greater reliability in future. Based on the observations presented in this 2008 Report, RTE's Power System Reliability Audit Mission considers that no new recommendations are needed beyond those expressed in previous reliability reports and during reliability audits. The publication of this yearly report is in keeping with RTE's goal to promote the follow-up over time of the evolution of reliability in its various aspects. RTE thus aims to contribute to the development of reliability culture, by encouraging an improved assessment by the different players (both RTE and network users) of the role they play in building reliability, and by advocating the taking into account of reliability and benchmarking in the European organisations of Transmission System Operators. Contents: 1 - Brief overview of the evolution of the internal and external environment; 2 - Operating situations encountered: climatic conditions, supply / demand balance management, operation of interconnections, management of internal congestion, contingencies affecting the transmission facilities; 3 - Evolution of the reliability reference guide: external reference guide: directives, laws, decrees, etc, ETSO, UCTE, ENTSO-E, contracting contributing to reliability, RTE internal reference guide; 4 - Evolution of measures contributing to reliability in the equipment field: intrinsic performances of components (generating sets, protection systems, operation PLC's, instrumentation and control, automatic frequency and voltage controls, transmission facilities, control systems, load

  4. Systems reliability analysis: applications of the SPARCS System-Reliability Assessment Computer Program

    International Nuclear Information System (INIS)

    Locks, M.O.

    1978-01-01

    SPARCS-2 (Simulation Program for Assessing the Reliabilities of Complex Systems, Version 2) is a PL/1 computer program for assessing (establishing interval estimates for) the reliability and the MTBF of a large and complex s-coherent system of any modular configuration. The system can consist of a complex logical assembly of independently failing attribute (binomial-Bernoulli) and time-to-failure (Poisson-exponential) components, without regard to their placement. Alternatively, it can be a configuration of independently failing modules, where each module has either or both attribute and time-to-failure components. SPARCS-2 also has an improved super modularity feature. Modules with minimal-cut unreliabiliy calculations can be mixed with those having minimal-path reliability calculations. All output has been standardized to system reliability or probability of success, regardless of the form in which the input data is presented, and whatever the configuration of modules or elements within modules

  5. Projections of energy requirements and their implications

    International Nuclear Information System (INIS)

    Hogroian, P.

    1978-01-01

    The subject is covered in sections, entitled as shown. Numerical data are indicated in parenthesis. The record of nuclear power forecasting (estimates of the growth of world nuclear power, penetration of the electric power market by nuclear power); brief review of energy forecasting techniques and problems; some views of future world energy demand (estimates of world primary energy requirements); possible allocations of energy resources to needs (allocation of resources (oil, oil from tar sands, shale, natural gas, coal, coal to gasification, hydroelectricity, renewable resources, nuclear) to the world's primary energy needs in the year 2000); observations on the adequacy of energy resources; implications for nuclear energy (postulated growth of world nuclear power, annual fuel cycle requirements of the world, annual uranium requirements of the world). (U.K.)

  6. Developing Reliable Life Support for Mars

    Science.gov (United States)

    Jones, Harry W.

    2017-01-01

    A human mission to Mars will require highly reliable life support systems. Mars life support systems may recycle water and oxygen using systems similar to those on the International Space Station (ISS). However, achieving sufficient reliability is less difficult for ISS than it will be for Mars. If an ISS system has a serious failure, it is possible to provide spare parts, or directly supply water or oxygen, or if necessary bring the crew back to Earth. Life support for Mars must be designed, tested, and improved as needed to achieve high demonstrated reliability. A quantitative reliability goal should be established and used to guide development t. The designers should select reliable components and minimize interface and integration problems. In theory a system can achieve the component-limited reliability, but testing often reveal unexpected failures due to design mistakes or flawed components. Testing should extend long enough to detect any unexpected failure modes and to verify the expected reliability. Iterated redesign and retest may be required to achieve the reliability goal. If the reliability is less than required, it may be improved by providing spare components or redundant systems. The number of spares required to achieve a given reliability goal depends on the component failure rate. If the failure rate is under estimated, the number of spares will be insufficient and the system may fail. If the design is likely to have undiscovered design or component problems, it is advisable to use dissimilar redundancy, even though this multiplies the design and development cost. In the ideal case, a human tended closed system operational test should be conducted to gain confidence in operations, maintenance, and repair. The difficulty in achieving high reliability in unproven complex systems may require the use of simpler, more mature, intrinsically higher reliability systems. The limitations of budget, schedule, and technology may suggest accepting lower and

  7. Individual Differences in Human Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey C. Joe; Ronald L. Boring

    2014-06-01

    While human reliability analysis (HRA) methods include uncertainty in quantification, the nominal model of human error in HRA typically assumes that operator performance does not vary significantly when they are given the same initiating event, indicators, procedures, and training, and that any differences in operator performance are simply aleatory (i.e., random). While this assumption generally holds true when performing routine actions, variability in operator response has been observed in multiple studies, especially in complex situations that go beyond training and procedures. As such, complexity can lead to differences in operator performance (e.g., operator understanding and decision-making). Furthermore, psychological research has shown that there are a number of known antecedents (i.e., attributable causes) that consistently contribute to observable and systematically measurable (i.e., not random) differences in behavior. This paper reviews examples of individual differences taken from operational experience and the psychological literature. The impact of these differences in human behavior and their implications for HRA are then discussed. We propose that individual differences should not be treated as aleatory, but rather as epistemic. Ultimately, by understanding the sources of individual differences, it is possible to remove some epistemic uncertainty from analyses.

  8. Distribution-Independent Reliable Learning

    OpenAIRE

    Kanade, Varun; Thaler, Justin

    2014-01-01

    We study several questions in the reliable agnostic learning framework of Kalai et al. (2009), which captures learning tasks in which one type of error is costlier than others. A positive reliable classifier is one that makes no false positive errors. The goal in the positive reliable agnostic framework is to output a hypothesis with the following properties: (i) its false positive error rate is at most $\\epsilon$, (ii) its false negative error rate is at most $\\epsilon$ more than that of the...

  9. Reliability of digital ulcer definitions as proposed by the UK Scleroderma Study Group: A challenge for clinical trial design.

    Science.gov (United States)

    Hughes, Michael; Tracey, Andrew; Bhushan, Monica; Chakravarty, Kuntal; Denton, Christopher P; Dubey, Shirish; Guiducci, Serena; Muir, Lindsay; Ong, Voon; Parker, Louise; Pauling, John D; Prabu, Athiveeraramapandian; Rogers, Christine; Roberts, Christopher; Herrick, Ariane L

    2018-06-01

    The reliability of clinician grading of systemic sclerosis-related digital ulcers has been reported to be poor to moderate at best, which has important implications for clinical trial design. The aim of this study was to examine the reliability of new proposed UK Scleroderma Study Group digital ulcer definitions among UK clinicians with an interest in systemic sclerosis. Raters graded (through a custom-built interface) 90 images (80 unique and 10 repeat) of a range of digital lesions collected from patients with systemic sclerosis. Lesions were graded on an ordinal scale of severity: 'no ulcer', 'healed ulcer' or 'digital ulcer'. A total of 23 clinicians - 18 rheumatologists, 3 dermatologists, 1 hand surgeon and 1 specialist rheumatology nurse - completed the study. A total of 2070 (1840 unique + 230 repeat) image gradings were obtained. For intra-rater reliability, across all images, the overall weighted kappa coefficient was high (0.71) and was moderate (0.55) when averaged across individual raters. Overall inter-rater reliability was poor (0.15). Although our proposed digital ulcer definitions had high intra-rater reliability, the overall inter-rater reliability was poor. Our study highlights the challenges of digital ulcer assessment by clinicians with an interest in systemic sclerosis and provides a number of useful insights for future clinical trial design. Further research is warranted to improve the reliability of digital ulcer definition/rating as an outcome measure in clinical trials, including examining the role for objective measurement techniques, and the development of digital ulcer patient-reported outcome measures.

  10. Morphine induces expression of platelet-derived growth factor in human brain microvascular endothelial cells: implication for vascular permeability.

    Directory of Open Access Journals (Sweden)

    Hongxiu Wen

    Full Text Available Despite the advent of antiretroviral therapy, complications of HIV-1 infection with concurrent drug abuse are an emerging problem. Morphine, often abused by HIV-infected patients, is known to accelerate neuroinflammation associated with HIV-1 infection. Detailed molecular mechanisms of morphine action however, remain poorly understood. Platelet-derived growth factor (PDGF has been implicated in a number of pathological conditions, primarily due to its potent mitogenic and permeability effects. Whether morphine exposure results in enhanced vascular permeability in brain endothelial cells, likely via induction of PDGF, remains to be established. In the present study, we demonstrated morphine-mediated induction of PDGF-BB in human brain microvascular endothelial cells, an effect that was abrogated by the opioid receptor antagonist-naltrexone. Pharmacological blockade (cell signaling and loss-of-function (Egr-1 approaches demonstrated the role of mitogen-activated protein kinases (MAPKs, PI3K/Akt and the downstream transcription factor Egr-1 respectively, in morphine-mediated induction of PDGF-BB. Functional significance of increased PDGF-BB manifested as increased breach of the endothelial barrier as evidenced by decreased expression of the tight junction protein ZO-1 in an in vitro model system. Understanding the regulation of PDGF expression may provide insights into the development of potential therapeutic targets for intervention of morphine-mediated neuroinflammation.

  11. Mechanical reliability of bulk high Tc superconductors

    International Nuclear Information System (INIS)

    Freiman, S.W.

    1990-01-01

    Most prospective applications for high T c superconductors in bulk form, e.g. magnets, motors, will require appreciable mechanical strength. Work at NIST [National Institute of Standards and Technology] has begun to address issues related to mechanical reliability. For example, recent studies on Ba-Y-Cu-O have shown that the intrinsic crack growth resistance, K IC , of crystals of this material is even smaller than was first reported, less than that of window glass, and is sensitive to moisture. Processing conditions, particularly sintering and annealing atmosphere, have been shown to have a major influence on microstructure and internal stresses in the material. Large internal stresses result from the tetragonal to orthorhombic phase transformation as well as the thermal expansion anisotropy in the grains of the ceramic. Because stress relief is absent, microcracks form which have a profound influence on strength

  12. Approach to reliability assessment

    International Nuclear Information System (INIS)

    Green, A.E.; Bourne, A.J.

    1975-01-01

    Experience has shown that reliability assessments can play an important role in the early design and subsequent operation of technological systems where reliability is at a premium. The approaches to and techniques for such assessments, which have been outlined in the paper, have been successfully applied in variety of applications ranging from individual equipments to large and complex systems. The general approach involves the logical and systematic establishment of the purpose, performance requirements and reliability criteria of systems. This is followed by an appraisal of likely system achievment based on the understanding of different types of variational behavior. A fundamental reliability model emerges from the correlation between the appropriate Q and H functions for performance requirement and achievement. This model may cover the complete spectrum of performance behavior in all the system dimensions

  13. Domain requirements for the Dock adapter protein in growth- cone signaling.

    Science.gov (United States)

    Rao, Y; Zipursky, S L

    1998-03-03

    Tyrosine phosphorylation has been implicated in growth-cone guidance through genetic, biochemical, and pharmacological studies. Adapter proteins containing src homology 2 (SH2) domains and src homology 3 (SH3) domains provide a means of linking guidance signaling through phosphotyrosine to downstream effectors regulating growth-cone motility. The Drosophila adapter, Dreadlocks (Dock), the homolog of mammalian Nck containing three N-terminal SH3 domains and a single SH2 domain, is highly specialized for growth-cone guidance. In this paper, we demonstrate that Dock can couple signals in either an SH2-dependent or an SH2-independent fashion in photoreceptor (R cell) growth cones, and that Dock displays different domain requirements in different neurons.

  14. A multi-criteria vertical coordination framework for a reliable aid distribution

    Energy Technology Data Exchange (ETDEWEB)

    Regis-Hernández, Fabiola; Mora-Vargas, Jaime; Ruíz, Angel

    2017-07-01

    This study proposes a methodology that translates multiple humanitarian supply chain stakeholders’ preferences from qualitative to quantitative values, enabling these preferences to be integrated into optimization models to ensure their balanced and simultaneous implementation during the decision-making process. Design/methodology/approach: An extensive literature review is used to justify the importance of developing a strategy that minimizes the impact of a lack of coordination on humanitarian logistics decisions. A methodology for a multi-criteria framework is presented that allows humanitarian stakeholders’ interests to be integrated into the humanitarian decision-making process. Findings: The findings suggest that integrating stakeholders’ interests into the humanitarian decision-making process will improve its reliability. Research limitations/implications: To further validate the weights of each stakeholder’s interests obtained from the literature review requires interviews with the corresponding organizations. However, the literature review supports the statements in this paper. Practical implications: The cost of a lack of coordination between stakeholders in humanitarian logistics has been increasing during the last decade. These coordination costs can be minimized if humanitarian logistics’ decision-makers measure and simultaneously consider multiple stakeholders’ preferences. Social implications: When stakeholders’ goals are aligned, the humanitarian logistics response becomes more efficient, increasing the quality of delivered aid and providing timely assistance to the affected population in order to minimize their suffering. This study provides a methodology that translates humanitarian supply chain stakeholders’ interests into quantitative values, enabling them to be integrated into mathematical models to ensure relief distribution based on the stakeholders’ preferences.

  15. A multi-criteria vertical coordination framework for a reliable aid distribution

    International Nuclear Information System (INIS)

    Regis-Hernández, Fabiola; Mora-Vargas, Jaime; Ruíz, Angel

    2017-01-01

    This study proposes a methodology that translates multiple humanitarian supply chain stakeholders’ preferences from qualitative to quantitative values, enabling these preferences to be integrated into optimization models to ensure their balanced and simultaneous implementation during the decision-making process. Design/methodology/approach: An extensive literature review is used to justify the importance of developing a strategy that minimizes the impact of a lack of coordination on humanitarian logistics decisions. A methodology for a multi-criteria framework is presented that allows humanitarian stakeholders’ interests to be integrated into the humanitarian decision-making process. Findings: The findings suggest that integrating stakeholders’ interests into the humanitarian decision-making process will improve its reliability. Research limitations/implications: To further validate the weights of each stakeholder’s interests obtained from the literature review requires interviews with the corresponding organizations. However, the literature review supports the statements in this paper. Practical implications: The cost of a lack of coordination between stakeholders in humanitarian logistics has been increasing during the last decade. These coordination costs can be minimized if humanitarian logistics’ decision-makers measure and simultaneously consider multiple stakeholders’ preferences. Social implications: When stakeholders’ goals are aligned, the humanitarian logistics response becomes more efficient, increasing the quality of delivered aid and providing timely assistance to the affected population in order to minimize their suffering. This study provides a methodology that translates humanitarian supply chain stakeholders’ interests into quantitative values, enabling them to be integrated into mathematical models to ensure relief distribution based on the stakeholders’ preferences

  16. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2014-01-01

    This book shows how to build in, evaluate, and demonstrate reliability and availability of components, equipment, systems. It presents the state-of-theart of reliability engineering, both in theory and practice, and is based on the author's more than 30 years experience in this field, half in industry and half as Professor of Reliability Engineering at the ETH, Zurich. The structure of the book allows rapid access to practical results. This final edition extend and replace all previous editions. New are, in particular, a strategy to mitigate incomplete coverage, a comprehensive introduction to human reliability with design guidelines and new models, and a refinement of reliability allocation, design guidelines for maintainability, and concepts related to regenerative stochastic processes. The set of problems for homework has been extended. Methods & tools are given in a way that they can be tailored to cover different reliability requirement levels and be used for safety analysis. Because of the Appendice...

  17. MEMS reliability: coming of age

    Science.gov (United States)

    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.

  18. Reliability of Wireless Sensor Networks

    Science.gov (United States)

    Dâmaso, Antônio; Rosa, Nelson; Maciel, Paulo

    2014-01-01

    Wireless Sensor Networks (WSNs) consist of hundreds or thousands of sensor nodes with limited processing, storage, and battery capabilities. There are several strategies to reduce the power consumption of WSN nodes (by increasing the network lifetime) and increase the reliability of the network (by improving the WSN Quality of Service). However, there is an inherent conflict between power consumption and reliability: an increase in reliability usually leads to an increase in power consumption. For example, routing algorithms can send the same packet though different paths (multipath strategy), which it is important for reliability, but they significantly increase the WSN power consumption. In this context, this paper proposes a model for evaluating the reliability of WSNs considering the battery level as a key factor. Moreover, this model is based on routing algorithms used by WSNs. In order to evaluate the proposed models, three scenarios were considered to show the impact of the power consumption on the reliability of WSNs. PMID:25157553

  19. Reliability on the move: safety and reliability in transportation

    International Nuclear Information System (INIS)

    Guy, G.B.

    1989-01-01

    The development of transportation has been a significant factor in the development of civilisation as a whole. Our technical ability to move people and goods now seems virtually limitless when one considers for example the achievements of the various space programmes. Yet our current achievements rely heavily on high standards of safety and reliability from equipment and the human component of transportation systems. Recent failures have highlighted our dependence on equipment and human reliability. This book represents the proceedings of the 1989 Safety and Reliability Society symposium held at Bath on 11-12 October 1989. The structure of the book follows the structure of the symposium itself and the papers selected represent current thinking the the wide field of transportation, and the areas of rail (6 papers, three on railway signalling), air including space (two papers), road (one paper), road and rail (two papers) and sea (three papers) are covered. There are four papers concerned with general transport issues. Three papers concerned with the transport of radioactive materials are indexed separately. (author)

  20. Implications of the Homogeneous Nucleation Barrier for Top-Down Crystallization in Mercury's Core

    Science.gov (United States)

    Huguet, L.; Hauck, S. A.; Van Orman, J. A.; Jing, Z.

    2018-05-01

    Crystallization of solids in planetary cores depends both on ambient temperatures falling below the liquidus and on the ability to nucleate crystal growth. We discuss the implications of the nucleation barrier for thermal evolution of Mercury's core.

  1. Enterprises’ Growth Potential in the European Union: Implications for Research and Innovation Policy

    OpenAIRE

    MONCADA PATERNO' CASTELLO Pietro; CINCERA Michele

    2012-01-01

    One of the main objectives of the new European research and innovation policy agenda is to favour the positive demographics (creation and growth) of EU companies operating in new/knowledge-intensive industries, especially Small and Medium Enterprises (SMEs). These companies play an important role in shaping the dynamism of the economy’s sectoral composition, favouring the transition towards more knowledge-intensive activities and in contributing to the overall economic growth objectives and m...

  2. The role of hormones and growth factors in the cellular proliferation control in mammals

    International Nuclear Information System (INIS)

    Armelin, H.A.

    1978-01-01

    A review is done about fibroblast proliferation, its control by classic hormones and hormonal growth factors, showing their main implications and the stage of this research at present. The control exerted on fibronlast proliferation by hormonal growth factors and classic hormones is demonstrated. The existence of basic mechanisms valid for all types of cells is suggested. Experiences are carried out with the aim of finding growth mutants useful in the elucidation of the biochemical mechanisms involved in growth regulation. Radiactive precursors and autoradiographic techniques are used in the research. (M.A.) [pt

  3. Reliability of Power Electronic Converter Systems

    DEFF Research Database (Denmark)

    -link capacitance in power electronic converter systems; wind turbine systems; smart control strategies for improved reliability of power electronics system; lifetime modelling; power module lifetime test and state monitoring; tools for performance and reliability analysis of power electronics systems; fault...... for advancing the reliability, availability, system robustness, and maintainability of PECS at different levels of complexity. Drawing on the experience of an international team of experts, this book explores the reliability of PECS covering topics including an introduction to reliability engineering in power...... electronic converter systems; anomaly detection and remaining-life prediction for power electronics; reliability of DC-link capacitors in power electronic converters; reliability of power electronics packaging; modeling for life-time prediction of power semiconductor modules; minimization of DC...

  4. Classifier Fusion With Contextual Reliability Evaluation.

    Science.gov (United States)

    Liu, Zhunga; Pan, Quan; Dezert, Jean; Han, Jun-Wei; He, You

    2018-05-01

    Classifier fusion is an efficient strategy to improve the classification performance for the complex pattern recognition problem. In practice, the multiple classifiers to combine can have different reliabilities and the proper reliability evaluation plays an important role in the fusion process for getting the best classification performance. We propose a new method for classifier fusion with contextual reliability evaluation (CF-CRE) based on inner reliability and relative reliability concepts. The inner reliability, represented by a matrix, characterizes the probability of the object belonging to one class when it is classified to another class. The elements of this matrix are estimated from the -nearest neighbors of the object. A cautious discounting rule is developed under belief functions framework to revise the classification result according to the inner reliability. The relative reliability is evaluated based on a new incompatibility measure which allows to reduce the level of conflict between the classifiers by applying the classical evidence discounting rule to each classifier before their combination. The inner reliability and relative reliability capture different aspects of the classification reliability. The discounted classification results are combined with Dempster-Shafer's rule for the final class decision making support. The performance of CF-CRE have been evaluated and compared with those of main classical fusion methods using real data sets. The experimental results show that CF-CRE can produce substantially higher accuracy than other fusion methods in general. Moreover, CF-CRE is robust to the changes of the number of nearest neighbors chosen for estimating the reliability matrix, which is appealing for the applications.

  5. A structure-based extracellular matrix expansion mechanism of fibrous tissue growth.

    Science.gov (United States)

    Kalson, Nicholas S; Lu, Yinhui; Taylor, Susan H; Starborg, Tobias; Holmes, David F; Kadler, Karl E

    2015-05-20

    Embryonic growth occurs predominately by an increase in cell number; little is known about growth mechanisms later in development when fibrous tissues account for the bulk of adult vertebrate mass. We present a model for fibrous tissue growth based on 3D-electron microscopy of mouse tendon. We show that the number of collagen fibrils increases during embryonic development and then remains constant during postnatal growth. Embryonic growth was explained predominately by increases in fibril number and length. Postnatal growth arose predominately from increases in fibril length and diameter. A helical crimp structure was established in embryogenesis, and persisted postnatally. The data support a model where the shape and size of tendon is determined by the number and position of embryonic fibroblasts. The collagen fibrils that these cells synthesise provide a template for postnatal growth by structure-based matrix expansion. The model has important implications for growth of other fibrous tissues and fibrosis.

  6. Towards a strategy of reliable fusion first-wall design

    International Nuclear Information System (INIS)

    Schultz, J.H.

    1981-05-01

    Fusion first walls are subject to a large number of possible failure mechanisms, including erosion due to sputtering, arcing, blistering and vaporization and crack growth due to thermal and magnetic stresses. Each of these failure mechanisms is poorly characterized and has the potential of being severe. A strategy for designing reliably in the face of great uncertainty is discussed. Topological features beneficial to reactor availability are identified. The integration of limiter pumping with rf wave launching is discussed, as a means of simplifying reactor design. The concept of a sewer limiter is introduced, as a possible long-life limiter topology. The concept of flexible armor is discussed, as a means of extending maximum life

  7. Modeling Energy & Reliability of a CNT based WSN on an HPC Setup

    Directory of Open Access Journals (Sweden)

    Rohit Pathak

    2010-07-01

    Full Text Available We have analyzed the effect of innovations in Nanotechnology on Wireless Sensor Networks (WSN and have modeled Carbon Nanotube (CNT based sensor nodes from a device prospective. A WSN model has been programmed in Simulink-MATLAB and a library has been developed. Integration of CNT in WSN for various modules such as sensors, microprocessors, batteries etc has been shown. Also average energy consumption for the system has been formulated and its reliability has been shown holistically. A proposition has been put forward on the changes needed in existing sensor node structure to improve its efficiency and to facilitate as well as enhance the assimilation of CNT based devices in a WSN. Finally we have commented on the challenges that exist in this technology and described the important factors that need to be considered for calculating reliability. This research will help in practical implementation of CNT based devices and analysis of their key effects on the WSN environment. The work has been executed on Simulink and Distributive Computing toolbox of MATLAB. The proposal has been compared to the recent developments and past experimental results reported in this field. This attempt to derieve the energy consumption and reliability implications will help in development of real devices using CNT which is a major hurdle in bringing the success from lab to commercial market. Recent research in CNT has been used to model an energy efficient model which will also lead to the development CAD tools. Library for Reliability and Energy consumption includes analysis of various parts of a WSN system which is being constructed from CNT. Nano routing in a CNT system is also implemented with its dependencies. Finally the computations were executed on a HPC setup and the model showed remarkable speedup.

  8. Insurance-growth nexus in Ghana: An autoregressive distributed lag bounds cointegration approach

    Directory of Open Access Journals (Sweden)

    Abdul Latif Alhassan

    2014-12-01

    Full Text Available This paper examines the long-run causal relationship between insurance penetration and economic growth in Ghana from 1990 to 2010. Using the autoregressive distributed lag (ARDL bounds approach to cointegration by Pesaran et al. (1996, 2001, the study finds a long-run positive relationship between insurance penetration and economic growth which implies that funds mobilized from insurance business have a long run impact on economic growth. A unidirectional causality was found to run from aggregate insurance penetration, life and non-life insurance penetration to economic growth to support the ‘supply-leading’ hypothesis. The findings have implications for insurance market development in Ghana.

  9. On the proposed new funding framework - a trajectory for growth or ...

    African Journals Online (AJOL)

    In essence, the funding framework although advocating a new trajectory towards sustainable growth, paradoxically appears to lead historically disadvantaged technikons towards negative entropy. This article explores the implications of the proposed funding mechanism on technikon research outputs and highlights the ...

  10. Vascular endothelial growth factors: multitasking functionality in metabolism, health and disease.

    Science.gov (United States)

    Smith, Gina A; Fearnley, Gareth W; Harrison, Michael A; Tomlinson, Darren C; Wheatcroft, Stephen B; Ponnambalam, Sreenivasan

    2015-07-01

    Vascular endothelial growth factors (VEGFs) bind to VEGF receptor tyrosine kinases (VEGFRs). The VEGF and VEGFR gene products regulate diverse regulatory pathways in mammalian development, health and disease. The interaction between a particular VEGF and its cognate VEGFR activates multiple signal transduction pathways which regulate different cellular responses including metabolism, gene expression, proliferation, migration, and survival. The family of VEGF isoforms regulate vascular physiology and promote tissue homeostasis. VEGF dysfunction is implicated in major chronic disease states including atherosclerosis, diabetes, and cancer. More recent studies implicate a strong link between response to VEGF and regulation of vascular metabolism. Understanding how this family of multitasking cytokines regulates cell and animal function has implications for treating many different diseases.

  11. Dementia does not preclude very reliable responding on the MMPI-2 RF: a case report.

    Science.gov (United States)

    Carone, Dominic A; Ben-Porath, Yossef S

    2014-01-01

    The Minnesota Multiphasic Personality Inventory (MMPI) family of personality tests has long been used by psychologists, in part because it provides extensive information on the validity of patient responses. Although much of the research on MMPI validity indicators has focused on over-reporting or under-reporting symptoms, the consistency (i.e., reliability, a requirement for validity) of responding is also critical to examine. Clinicians tend to avoid using the MMPI-2 or the MMPI-2-RF (Restructured Form) in patients with dementia based on the belief that severe cognitive impairment would make reliable responding impossible given the large number of items (567 and 338, respectively). In contrast with this belief we present the case of a 65-year-old woman with severe memory impairments and executive dysfunction due to a non-specific dementia syndrome who was able to provide remarkably consistent responding on the MMPI-2-RF. Implications and future directions are discussed.

  12. Reliability of construction materials

    International Nuclear Information System (INIS)

    Merz, H.

    1976-01-01

    One can also speak of reliability with respect to materials. While for reliability of components the MTBF (mean time between failures) is regarded as the main criterium, this is replaced with regard to materials by possible failure mechanisms like physical/chemical reaction mechanisms, disturbances of physical or chemical equilibrium, or other interactions or changes of system. The main tasks of the reliability analysis of materials therefore is the prediction of the various failure reasons, the identification of interactions, and the development of nondestructive testing methods. (RW) [de

  13. RTE - 2013 Reliability Report

    International Nuclear Information System (INIS)

    Denis, Anne-Marie

    2014-01-01

    RTE publishes a yearly reliability report based on a standard model to facilitate comparisons and highlight long-term trends. The 2013 report is not only stating the facts of the Significant System Events (ESS), but it moreover underlines the main elements dealing with the reliability of the electrical power system. It highlights the various elements which contribute to present and future reliability and provides an overview of the interaction between the various stakeholders of the Electrical Power System on the scale of the European Interconnected Network. (author)

  14. Driving factors of urban land growth in Guangzhou and its implications for sustainable development

    Science.gov (United States)

    Cui, Xuezhu; Li, Shaoying; Wang, Xuetong; Xue, Xiaolong

    2018-04-01

    Since 2000, China's urban land has expanded at a dramatic speed because of the country's rapid urbanization. The country has been experiencing unbalanced development between rural and urban areas, causing serious challenges such as agricultural security and land resources waste. Effectively evaluating the driving factors of urban land growth is essential for improving efficient land use management and sustainable urban development. This study established a principal component regression model based on eight indicators to identify their influences on urban land growth in Guangzhou. The results provided a grouping analysis of the driving factors, and found that economic growth, urban population, and transportation development are the driving forces of urban land growth of Guangzhou, while the tertiary industry has an opposite effect. The findings led to further suggestions and recommendations for urban sustainable development. Hence, local governments should design relevant policies for achieving the rational development of urban land use and strategic planning on urban sustainable development.

  15. How reliable are Functional Movement Screening scores? A systematic review of rater reliability.

    Science.gov (United States)

    Moran, Robert W; Schneiders, Anthony G; Major, Katherine M; Sullivan, S John

    2016-05-01

    Several physical assessment protocols to identify intrinsic risk factors for injury aetiology related to movement quality have been described. The Functional Movement Screen (FMS) is a standardised, field-expedient test battery intended to assess movement quality and has been used clinically in preparticipation screening and in sports injury research. To critically appraise and summarise research investigating the reliability of scores obtained using the FMS battery. Systematic literature review. Systematic search of Google Scholar, Scopus (including ScienceDirect and PubMed), EBSCO (including Academic Search Complete, AMED, CINAHL, Health Source: Nursing/Academic Edition), MEDLINE and SPORTDiscus. Studies meeting eligibility criteria were assessed by 2 reviewers for risk of bias using the Quality Appraisal of Reliability Studies checklist. Overall quality of evidence was determined using van Tulder's levels of evidence approach. 12 studies were appraised. Overall, there was a 'moderate' level of evidence in favour of 'acceptable' (intraclass correlation coefficient ≥0.6) inter-rater and intra-rater reliability for composite scores derived from live scoring. For inter-rater reliability of composite scores derived from video recordings there was 'conflicting' evidence, and 'limited' evidence for intra-rater reliability. For inter-rater reliability based on live scoring of individual subtests there was 'moderate' evidence of 'acceptable' reliability (κ≥0.4) for 4 subtests (Deep Squat, Shoulder Mobility, Active Straight-leg Raise, Trunk Stability Push-up) and 'conflicting' evidence for the remaining 3 (Hurdle Step, In-line Lunge, Rotary Stability). This review found 'moderate' evidence that raters can achieve acceptable levels of inter-rater and intra-rater reliability of composite FMS scores when using live ratings. Overall, there were few high-quality studies, and the quality of several studies was impacted by poor study reporting particularly in relation to

  16. 2017 NREL Photovoltaic Reliability Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-15

    NREL's Photovoltaic (PV) Reliability Workshop (PVRW) brings together PV reliability experts to share information, leading to the improvement of PV module reliability. Such improvement reduces the cost of solar electricity and promotes investor confidence in the technology -- both critical goals for moving PV technologies deeper into the electricity marketplace.

  17. 46 CFR 169.619 - Reliability.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Reliability. 169.619 Section 169.619 Shipping COAST... Electrical Steering Systems § 169.619 Reliability. (a) Except where the OCMI judges it impracticable, the... be below that necessary for the safe navigation of the vessel. (c) The strength and reliability of...

  18. Equipment Reliability Program in NPP Krsko

    International Nuclear Information System (INIS)

    Skaler, F.; Djetelic, N.

    2006-01-01

    Operation that is safe, reliable, effective and acceptable to public is the common message in a mission statement of commercial nuclear power plants (NPPs). To fulfill these goals, nuclear industry, among other areas, has to focus on: 1 Human Performance (HU) and 2 Equipment Reliability (EQ). The performance objective of HU is as follows: The behaviors of all personnel result in safe and reliable station operation. While unwanted human behaviors in operations mostly result directly in the event, the behavior flaws either in the area of maintenance or engineering usually cause decreased equipment reliability. Unsatisfied Human performance leads even the best designed power plants into significant operating events, which can be found as well-known examples in nuclear industry. Equipment reliability is today recognized as the key to success. While the human performance at most NPPs has been improving since the start of WANO / INPO / IAEA evaluations, the open energy market has forced the nuclear plants to reduce production costs and operate more reliably and effectively. The balance between these two (opposite) goals has made equipment reliability even more important for safe, reliable and efficient production. Insisting on on-line operation by ignoring some principles of safety could nowadays in a well-developed safety culture and human performance environment exceed the cost of electricity losses. In last decade the leading USA nuclear companies put a lot of effort to improve equipment reliability primarily based on INPO Equipment Reliability Program AP-913 at their NPP stations. The Equipment Reliability Program is the key program not only for safe and reliable operation, but also for the Life Cycle Management and Aging Management on the way to the nuclear power plant life extension. The purpose of Equipment Reliability process is to identify, organize, integrate and coordinate equipment reliability activities (preventive and predictive maintenance, maintenance

  19. The Rise of Urban Slum in Nigeria: Implications on the Urban ...

    African Journals Online (AJOL)

    ... defacement of the urban landscape in Nigeria. It recommends that Government and city planners should provide affordable land and low cost housing for the urban dwellers. This will enable people to own their property or rent as the case may be. Keywords: Urban Slum, Urban Landscape, Implication, Population, Growth

  20. Problem of nuclear power plant reliability

    International Nuclear Information System (INIS)

    Popyrin, L.S.; Nefedov, Yu.V.

    1989-01-01

    The problem of substantiation of rational and methods of ensurance of NPP reliability at the stage of its designing has been studied. It is shown that the optimal level of NPP reliability is determined by coordinating solution of the proiblems for optimization of reliability of power industry, heat and power supply and nuclear power generation systems comprising NPP, and problems of reliability optimization of NPP proper, as a complex engineering system. The conclusion is made that the greatest attention should be paid to the development of mathematical models of reliability, taking into account different methods of equipment redundancy, as well as dependence of failures on barious factors, improvement of NPP reliability indices, development of data base, working out of the complec of consistent standards of reliability. 230 refs.; 2 figs.; 1 tab

  1. The Vicious Cycle of Myostatin Signaling in Sarcopenic Obesity: Myostatin Role in Skeletal Muscle Growth, Insulin Signaling and Implications for Clinical Trials.

    Science.gov (United States)

    Consitt, L A; Clark, B C

    2018-01-01

    The age-related loss of skeletal muscle (sarcopenia) is a major health concern as it is associated with physical disability, metabolic impairments, and increased mortality. The coexistence of sarcopenia with obesity, termed 'sarcopenic obesity', contributes to skeletal muscle insulin resistance and the development of type 2 diabetes, a disease prevalent with advancing age. Despite this knowledge, the mechanisms contributing to sarcopenic obesity remain poorly understood, preventing the development of targeted therapeutics. This article will discuss the clinical and physiological consequences of sarcopenic obesity and propose myostatin as a potential candidate contributing to this condition. A special emphasis will be placed on examining the role of myostatin signaling in impairing both skeletal muscle growth and insulin signaling. In addition, the role of myostatin in regulating muscle-to fat cross talk, further exacerbating metabolic dysfunction in the elderly, will be highlighted. Lastly, we discuss how this knowledge has implications for the design of myostatin-inhibitor clinical trials.

  2. Mathematical analysis of a model for the growth of the bovine corpus luteum

    KAUST Repository

    Prokopiou, Sotiris A.; Byrne, Helen M.; Jeffrey, Mike R.; Robinson, Robert S.; Mann, George E.; Owen, Markus R.

    2013-01-01

    growth is predicted. The implications of these results for cow fertility are also discussed. For example, inadequate angiogenesis has been linked to infertility in dairy cows. © 2013 Springer-Verlag Berlin Heidelberg.

  3. Reliability and validity of aggressive driving measures in China.

    Science.gov (United States)

    Li, Fengzhi; Li, Changji; Long, Yunfang; Zhan, Chenglie; Hennessy, Dwight

    2004-12-01

    The present research was designed to examine the psychometric properties of Chinese versions of the Self Report Driver Behavior Aggression and Assertiveness subscales, the Driving Vengeance Questionnaire, and the Violent Driving Questionnaire. Study 1 found that the all scales demonstrated good internal consistency, with alphas ranging from .76 to .87 and that assertive driving was related to demerit points received over the past 12 months while driver aggression and violence were linked to collisions over the past 12 months. Study 2 found that the scales exhibited reasonable test-retest reliability, with correlations ranging from .82 to .89. Finally, Study 3 showed that each scale was predicted by other dangerous driving attitudes and behaviors, similar to the original versions. The consistency between the translated and original scales, the implications for use in a Chinese sample, and the uniformity of actions in the traffic environment across cultures are discussed.

  4. Impact of Remittances on Economic Growth and Poverty: Evidence from Pakistan

    OpenAIRE

    Qayyum, Abdul; Javid, Muhammad; Arif, Umaima

    2008-01-01

    The study focused on the importance of remittances inflow and its implication for economic growth and poverty reduction in Pakistan. By using ARDL approach we analyze the impact of remittances inflow on economic growth and poverty in Pakistan for the period 1973-2007. The district wise analysis of poverty suggest that overseas migration contributes to poverty alleviation in the districts of Punjab, Sindh and Balochistan however NWFP is not portraying a clear picture. The empirical ev...

  5. Reliability and mechanical design

    International Nuclear Information System (INIS)

    Lemaire, Maurice

    1997-01-01

    A lot of results in mechanical design are obtained from a modelisation of physical reality and from a numerical solution which would lead to the evaluation of needs and resources. The goal of the reliability analysis is to evaluate the confidence which it is possible to grant to the chosen design through the calculation of a probability of failure linked to the retained scenario. Two types of analysis are proposed: the sensitivity analysis and the reliability analysis. Approximate methods are applicable to problems related to reliability, availability, maintainability and safety (RAMS)

  6. Human Reliability Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Reliability data book

    International Nuclear Information System (INIS)

    Bento, J.P.; Boerje, S.; Ericsson, G.; Hasler, A.; Lyden, C.O.; Wallin, L.; Poern, K.; Aakerlund, O.

    1985-01-01

    The main objective for the report is to improve failure data for reliability calculations as parts of safety analyses for Swedish nuclear power plants. The work is based primarily on evaluations of failure reports as well as information provided by the operation and maintenance staff of each plant. In the report are presented charts of reliability data for: pumps, valves, control rods/rod drives, electrical components, and instruments. (L.E.)

  8. Photovoltaic performance and reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Mrig, L. [ed.

    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.

  9. Economic growth of the United States: perspective and prospective. [Monograph

    Energy Technology Data Exchange (ETDEWEB)

    Fabricant, S

    1979-01-01

    A post-World War II analysis of the potential for US economic expansion projects a continuation of the basic social and economic expectations and international relations and of the upward trend of labor input, labor productivity, and national output. How economic growth of the future will differ as a result of global changes in population and resources is examined in the context of other national objectives. The rapid increase in labor productivity during the postwar period was taken in the form of income rather than leisure. This led to a growth of goods and real per capita income as well as higher standards of living, education, and economic stability. The implications for future growth indicate the need to slow the growth of the national product in line with the rate of population growth. The improved welfare of the people should be the overall goal of which economic growth is one component. 23 tables. (DCK)

  10. Time-variant flexural reliability of RC beams with externally bonded CFRP under combined fatigue-corrosion actions

    International Nuclear Information System (INIS)

    Bigaud, David; Ali, Osama

    2014-01-01

    Time-variant reliability analysis of RC highway bridges strengthened with carbon fibre reinforced polymer CFRP laminates under four possible competing damage modes (concrete crushing, steel rupture after yielding, CFRP rupture and FRP plate debonding) and three degradation factors is analyzed in terms of reliability index β using FORM. The first degradation factor is chloride-attack corrosion which induces reduction in steel area and concrete cover cracking at characteristic key times (corrosion initiation, severe surface cover cracking). The second degradation factor considered is fatigue which leads to damage in concrete and steel rebar. Interaction between corrosion and fatigue crack growth in steel reinforcing bars is implemented. The third degradation phenomenon is the CFRP properties deterioration due to aging. Considering these three degradation factors, the time-dependent flexural reliability profile of a typical simple 15 m-span intermediate girder of a RC highway bridge is constructed under various traffic volumes and under different corrosion environments. The bridge design options follow AASHTO-LRFD specifications. Results of the study have shown that the reliability is very sensitive to factors governing the corrosion. Concrete damage due to fatigue slightly affects reliability profile of non-strengthened section, while service life after strengthening is strongly related to fatigue damage in concrete. - Highlights: • We propose a method to follow the time-variant reliability of strengthened RC beams. • We consider multiple competing failure modes of CFRP strengthened RC beams. • We consider combined degradation mechanisms (corrosion, fatigue, ageing of CFRP)

  11. AECL's reliability and maintainability program

    International Nuclear Information System (INIS)

    Wolfe, W.A.; Nieuwhof, G.W.E.

    1976-05-01

    AECL's reliability and maintainability program for nuclear generating stations is described. How the various resources of the company are organized to design and construct stations that operate reliably and safely is shown. Reliability and maintainability includes not only special mathematically oriented techniques, but also the technical skills and organizational abilities of the company. (author)

  12. Variability and reliability of the vastus lateralis muscle anatomy.

    Science.gov (United States)

    D'Arpa, Salvatore; Toia, Francesca; Brenner, Erich; Melloni, Carlo; Moschella, Francesco; Cordova, Adriana

    2016-08-01

    The aims of this study are to investigate the variability of the morphological and neurovascular anatomy of the vastus lateralis (VL) muscle and to describe the relationships among its intramuscular partitions and with the other muscles of the quadriceps femoris. Clinical implications in its reliability as a flap donor are also discussed. In 2012, the extra- and intramuscular neurovascular anatomy of the VL was investigated in 10 cadaveric lower limbs. In three specimens, the segmental arterial pedicles were injected with latex of different colors to point out their anastomotic connections. The morphological anatomy was investigated with regard to the mutual relationship of the three muscular partitions and the relation of the VL with the other muscles of the quadriceps femoris. The VL has a segmental morphological anatomy. However, the fibers of its three partitions interconnect individually and with the other bellies of the quadriceps femoris, particularly, in several variable portions with the vastus intermedius and mainly in the posterior part of the VL. The lateral circumflex femoral artery and its branches have variable origin, but demonstrate constant segmental distribution. Intramuscular dissection and colored latex injections show a rich anastomotic vascular network among the three partitions. Moderate variability exists in both the myological and the neurovascular anatomy of the VL. Despite this variability, the anatomy of the VL always has a constant segmental pattern, which makes the VL a reliable flap donor. Detailed knowledge of the VL anatomy could have useful applications in a broad clinical field.

  13. Technology success: Integration of power plant reliability and effective maintenance

    International Nuclear Information System (INIS)

    Ferguson, K.

    2008-01-01

    The nuclear power generation sector has a tradition of utilizing technology as a key attribute for advancement. Companies that own, manage, and operate nuclear power plants can be expected to continue to rely on technology as a vital element of success. Inherent with the operations of the nuclear power industry in many parts of the world is the close connection between efficiency of power plant operations and successful business survival. The relationship among power plant availability, reliability of systems and components, and viability of the enterprise is more evident than ever. Technology decisions need to be accomplished that reflect business strategies, work processes, as well as needs of stakeholders and authorities. Such rigor is needed to address overarching concerns such as power plant life extension and license renewal, new plant orders, outage management, plant safety, inventory management etc. Particular to power plant reliability, the prudent leveraging of technology as a key to future success is vital. A dominant concern is effective asset management as physical plant assets age. Many plants are in, or are entering in, a situation in which systems and component design life and margins are converging such that failure threats can come into play with increasing frequency. Wisely selected technologies can be vital to the identification of emerging threats to reliable performance of key plant features and initiating effective maintenance actions and investments that can sustain or enhance current reliability in a cost effective manner. This attention to detail is vital to investment in new plants as well This paper and presentation will address (1) specific technology success in place at power plants, including nuclear, that integrates attention to attaining high plant reliability and effective maintenance actions as well as (2) complimentary actions that maximize technology success. In addition, the range of benefits that accrue as a result of

  14. North American Electric Reliability Council (NERC) Reliability Coordinators

    Data.gov (United States)

    Department of Homeland Security — ERC is an international regulatory authority that works to improve the reliability of the bulk power system in North America. NERC works with many different regional...

  15. Optimal, Reliability-Based Code Calibration

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2002-01-01

    Reliability based code calibration is considered in this paper. It is described how the results of FORM based reliability analysis may be related to the partial safety factors and characteristic values. The code calibration problem is presented in a decision theoretical form and it is discussed how...... of reliability based code calibration of LRFD based design codes....

  16. Reliability Generalization: Exploring Variation of Reliability Coefficients of MMPI Clinical Scales Scores.

    Science.gov (United States)

    Vacha-Haase, Tammi; Kogan, Lori R.; Tani, Crystal R.; Woodall, Renee A.

    2001-01-01

    Used reliability generalization to explore the variance of scores on 10 Minnesota Multiphasic Personality Inventory (MMPI) clinical scales drawing on 1,972 articles in the literature on the MMPI. Results highlight the premise that scores, not tests, are reliable or unreliable, and they show that study characteristics do influence scores on the…

  17. Some areas of reliability technique which have been neglected to some extent - maintainability - human reliability - mechanical reliability - repairable systems

    International Nuclear Information System (INIS)

    Akersten, P.A.

    1985-01-01

    The present thesis consists of four papers, three of which are of a expositary nature and one more theoretical. The first two papers have a natural coupling to the man-machine interface. The first paper is devoted to the concept of maintainability and the role of man as maintenance technician. The second paper discusses aspects of human reliability, mainly studying man as operator. However, maintenance tasks can be studied in the same manner. The third paper concerns reliability prediction for mechanical components. This is an area of vital importance for the reliability practitioner, who needs realistic and easy-to-use mathematical models for different failure modes. The fourth paper discusses mathematical models for repairable systems, especially the problem of testing whether a constant event intensity model is adequate or not. (author)

  18. The Creativity of Korean Leaders and Its Implications for Creativity Education

    Science.gov (United States)

    Cho, Younsoon; Chung, Hyeyoung; Choi, Kyoulee; Suh, Yewon; Seo, Choyoung

    2011-01-01

    This research explores the promoting elements of Korean leaders' creative achievements, and provides implications for creativity education which are suitable in the Korean sociocultural context. In-depth interviews focusing on their school life and personal growth were held with twelve leaders, four each in the fields of science, humanities, and…

  19. OPTIMIZATION OF THE RELIABILITY OF AGRICULTURAL CONSUMERS ELECTRICITY DISTRIBUTING AND SUPPLY SYSTEMS

    Directory of Open Access Journals (Sweden)

    Lupushor I.

    2007-12-01

    Full Text Available The problems of the optimization reliability in electrical networks of the different class of voltage have probabilistic nature, they discretely change and depend on the number of factors both definite and indefinite and have importance by selection of electric equipment, graph of development of electrical networks and voltage levels. The definition of the major factors, which have determining significance on their value and speed of their change allow to elaborate methods of their optimization and to elaborate effective methods of their growth limitation in electrical networks with the different class of voltage.

  20. An evaluation of the multi-state node networks reliability using the traditional binary-state networks reliability algorithm

    International Nuclear Information System (INIS)

    Yeh, W.-C.

    2003-01-01

    A system where the components and system itself are allowed to have a number of performance levels is called the Multi-state system (MSS). A multi-state node network (MNN) is a generalization of the MSS without satisfying the flow conservation law. Evaluating the MNN reliability arises at the design and exploitation stage of many types of technical systems. Up to now, the known existing methods can only evaluate a special MNN reliability called the multi-state node acyclic network (MNAN) in which no cyclic is allowed. However, no method exists for evaluating the general MNN reliability. The main purpose of this article is to show first that each MNN reliability can be solved using any the traditional binary-state networks (TBSN) reliability algorithm with a special code for the state probability. A simple heuristic SDP algorithm based on minimal cuts (MC) for estimating the MNN reliability is presented as an example to show how the TBSN reliability algorithm is revised to solve the MNN reliability problem. To the author's knowledge, this study is the first to discuss the relationships between MNN and TBSN and also the first to present methods to solve the exact and approximated MNN reliability. One example is illustrated to show how the exact MNN reliability is obtained using the proposed algorithm

  1. Exact reliability quantification of highly reliable systems with maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bris, Radim, E-mail: radim.bris@vsb.c [VSB-Technical University Ostrava, Faculty of Electrical Engineering and Computer Science, Department of Applied Mathematics, 17. listopadu 15, 70833 Ostrava-Poruba (Czech Republic)

    2010-12-15

    When a system is composed of highly reliable elements, exact reliability quantification may be problematic, because computer accuracy is limited. Inaccuracy can be due to different aspects. For example, an error may be made when subtracting two numbers that are very close to each other, or at the process of summation of many very different numbers, etc. The basic objective of this paper is to find a procedure, which eliminates errors made by PC when calculations close to an error limit are executed. Highly reliable system is represented by the use of directed acyclic graph which is composed from terminal nodes, i.e. highly reliable input elements, internal nodes representing subsystems and edges that bind all of these nodes. Three admissible unavailability models of terminal nodes are introduced, including both corrective and preventive maintenance. The algorithm for exact unavailability calculation of terminal nodes is based on merits of a high-performance language for technical computing MATLAB. System unavailability quantification procedure applied to a graph structure, which considers both independent and dependent (i.e. repeatedly occurring) terminal nodes is based on combinatorial principle. This principle requires summation of a lot of very different non-negative numbers, which may be a source of an inaccuracy. That is why another algorithm for exact summation of such numbers is designed in the paper. The summation procedure uses benefits from a special number system with the base represented by the value 2{sup 32}. Computational efficiency of the new computing methodology is compared with advanced simulation software. Various calculations on systems from references are performed to emphasize merits of the methodology.

  2. Alternatives to Growth: Education for a Stable Society. Fastback 72.

    Science.gov (United States)

    Bjork, Robert M.; Fraser, Stewart E.

    This essay considers the need for economic retrenchment, environmental conservation, and the implications of these positions for teaching. Facing an environmental crisis, overpopulation, and an ever-increasing reduction of natural resources, education in the future must concentrate on teaching about the futility of growth, planned and unplanned.…

  3. Medical device reliability and associated areas

    National Research Council Canada - National Science Library

    Dhillon, Balbir S

    2000-01-01

    .... Although the history of reliability engineering can be traced back to World War II, the application of reliability engineering concepts to medical devices is a fairly recent idea that goes back to the latter part of the 1960s when many publications on medical device reliability emerged. Today, a large number of books on general reliability have been...

  4. Supplementation of serum free media with HT is not sufficient to restore growth properties of DHFR-/- cells in fed-batch processes - Implications for designing novel CHO-based expression platforms.

    Science.gov (United States)

    Florin, Lore; Lipske, Carolin; Becker, Eric; Kaufmann, Hitto

    2011-04-10

    DHFR-deficient CHO cells are the most commonly used host cells in the biopharmaceutical industry and over the years, individual substrains have evolved, some have been engineered with improved properties and platform technologies have been designed around them. Unexpectedly, we have observed that different DHFR-deficient CHO cells show only poor growth in fed-batch cultures even in HT supplemented medium, whereas antibody producer cells derived from these hosts achieved least 2-3 fold higher peak cell densities. Using a set of different expression vectors, we were able to show that this impaired growth performance was not due to the selection procedure possibly favouring fast growing clones, but a direct consequence of DHFR deficiency. Re-introduction of the DHFR gene reproducibly restored the growth phenotype to the level of wild-type CHO cells or even beyond which seemed to be dose-dependent. The requirement for a functional DHFR gene to achieve optimal growth under production conditions has direct implications for cell line generation since it suggests that changing to a selection system other than DHFR would require another CHO host which - especially for transgenic CHO strains and tailor-suited process platforms - this could mean significant investments and potential changes in product quality. In these cases, DHFR engineering of the current CHO-DG44 or DuxB11-based host could be an attractive alternative. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Effects of Phytoplankton Growth Phase on the Formation and Properties of Marine Snow

    Science.gov (United States)

    Montgomery, Q. W.; Proctor, K. W.; Prairie, J. C.

    2016-02-01

    Marine snow aggregates often dominate carbon export from the upper mixed layer to the deep ocean. Thus, understanding the formation and the properties of these aggregates is essential to the study of the biological pump. Aggregate formation is determined by both the encounter rate and the stickiness of the particles that they are composed of. Stickiness of phytoplankton has been linked to production of transparent exopolymer particles (TEP), which has been previously shown to vary in concentration throughout different parts of the phytoplankton growth cycle. The objective of this study is to determine the effects of the growth phase of the diatom Thalassiosira weissflogii to both TEP production and the properties of the resulting aggregates produced. Cultures of T. weissflogii were stopped at separate phases of the phytoplankton growth curve and incubated in rotating cylindrical tanks to form aggregates. Aggregate properties such as size, density, and porosity were measured at the end of each period of roller incubation. Preliminary results describe little variation in the size of the aggregates formed from different parts of the growth phase, but show a significant effect of growth phase on aggregate density. Density is an important factor in the settling of marine aggregates. Therefore, variations in aggregate density during different growth phases may have large implications for the efficiency of the biological pump during different stages of a phytoplankton bloom. Further examination will be performed on the potential effects of TEP abundance on the properties of the aggregates formed at separate growth phases and the resulting implications for carbon flux.

  6. Insulin-like growth factor family and combined antisense approach in therapy of lung carcinoma.

    OpenAIRE

    Pavelić, Jasminka; Pavelić, Ljubomir; Karadza, Jerolim; Krizanac, Simun; Unesić, Josip; Spaventi, Sime; Pavelić, Kresimir

    2002-01-01

    BACKGROUND: Perturbation in a level of any peptide from insulin-like growth factor (IGF) family (ligands, receptors, and binding proteins) seems to be implicated in lung cancer formation; IGF ligands and IGF-I receptor through their mitogenic and anti-apoptotic action, and the mannose 6-phosphate/insulin-like growth factor II receptor (M6-P/IGF-IIR) possibly as a tumor suppressor. MATERIALS AND METHODS: To determine the identity, role, and mutual relationship of IGFs in lung cancer growth and...

  7. Evaluation of growth hormone release and human growth hormone treatment in children with cranial irradiation-associated short stature

    International Nuclear Information System (INIS)

    Romshe, C.A.; Zipf, W.B.; Miser, A.; Miser, J.; Sotos, J.F.; Newton, W.A.

    1984-01-01

    We studied nine children who had received cranial irradiation for various malignancies and subsequently experienced decreased growth velocity. Their response to standard growth hormone stimulation and release tests were compared with that in seven children with classic GH deficiency and in 24 short normal control subjects. With arginine and L-dopa stimulation, six of nine patients who received radiation had a normal GH response (greater than 7 ng/ml), whereas by design none of the GH deficient and all of the normal children had a positive response. Only two of nine patients had a normal response to insulin hypoglycemia, with no significant differences in the mean maximal response of the radiation and the GH-deficient groups. Pulsatile secretion was not significantly different in the radiation and GH-deficient groups, but was different in the radiation and normal groups. All subjects in the GH-deficient and radiation groups were given human growth hormone for 1 year. Growth velocity increased in all, with no significant difference in the response of the two groups when comparing the z scores for growth velocity of each subject's bone age. We recommend a 6-month trial of hGH in children who have had cranial radiation and are in prolonged remission with a decreased growth velocity, as there is no completely reliable combination of GH stimulation or release tests to determine their response

  8. Integrated system reliability analysis

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    Specific targets: 1) The report shall describe the state of the art of reliability and risk-based assessment of wind turbine components. 2) Development of methodology for reliability and risk-based assessment of the wind turbine at system level. 3) Describe quantitative and qualitative measures...

  9. The Implications of Psychosocial Theory for Personal Growth in the Family.

    Science.gov (United States)

    Newman, Philip R.; Newman, Barbara M.

    Psychosocial theory, based on the ideas of Erik Erikson and Robert Havighurst, is proposed as a useful framework for conceptualizing the potential for growth within the family. Erikson's (1950) eight stage theory of psychosocial development and Havighurst's (1959) concept of developmental tasks are used to take account of the stages of development…

  10. Limits to growth? : China's rise and its implications for Europe

    OpenAIRE

    Schmidt, Volker H.

    2006-01-01

    "The paper outlines two future scenarios, one 'pessimistic', the other more 'optimistic'. The first assumes that definite limits to growth exist and that, to the extent that this is still possible, economic policies must be radically altered to prevent the collapse of our ecosystems ('global warming'). If this assessment were correct, then we would probably be doomed. For even if all understood the dangers, it would still seem to be extremely unlikely that the major world powers will exit the...

  11. Foundations for a time reliability correlation system to quantify human reliability

    International Nuclear Information System (INIS)

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

    1988-01-01

    Time reliability correlations (TRCs) have been used in human reliability analysis (HRA) in conjunction with probabilistic risk assessment (PRA) to quantify post-initiator human failure events. The first TRCs were judgmental but recent data taken from simulators have provided evidence for development of a system of TRCs. This system has the equational form: t = tau R X tau U , where the first factor is the lognormally distributed random variable of successful response time, derived from the simulator data, and the second factor is a unitary lognormal random variable to account for uncertainty in the model. The first random variable is further factored into a median response time and a factor to account for the dominant type of behavior assumed to be involved in the response and a second factor to account for other influences on the reliability of the response

  12. Reliability of 4-meter and 10-meter walk tests after lower extremity surgery.

    Science.gov (United States)

    Unver, Bayram; Baris, Refik Hilmi; Yuksel, Ertugrul; Cekmece, Senol; Kalkan, Serpil; Karatosun, Vasfi

    2017-12-01

    To investigate the test-retest reliability of the 4-meter walk test (4 MWT) and 10-meter walk test (10 MWT) in patients undergoing lower extremity surgery during inpatient rehabilitation. In all, 102 patients with total hip arthroplasty (THA), total knee arthroplasty (TKA), lower extremity fracture (LEF) and soft tissue operation were recruited. Patients performed two 4 MWT and two 10 MWT trials on the same day. The same researcher performed all the measurements to avoid inter-rater variability. The 4 MWT and 10 MWT were shown to have excellent test-retest reliability. The ICCs for the 4 MWT and 10 MWT were found as 0.94 and 0.95, respectively. The SEMs for the 4 MWT and 10 MWT were 2.0 and 5.5 seconds, respectively. The smallest real difference at the 95% confidence level (SRD95) was 5.5 seconds for the 4 MWT and 12.2 seconds for 10 MWT and SRD95 percentage was 31.2 for the 4 MWT and 28.5 for the 10 MWT. Both the 4 MWT and the 10 MWT have excellent reliability in patients undergoing lower extremity surgery such as TKA, THA, LEF and soft tissue operation during inpatient rehabilitation. Clinicians and researchers can be confident that changes above the SRD95s for the different patient groups, for both sexes and with regard to weight-bearing status, represent a real clinical change in rehabilitation process. Implications for Rehabilitation The 4 MWT and the 10 MWT are simple methods and were also shown to be reliable measurement methods in many patient groups. This study illustrates that the test-retest reliability of the 4 MWT and 10 MWT are excellent in patients undergoing lower extremity surgery during inpatient rehabilitation (ICC: 0.94 for 4 MWT, ICC: 0.95 for 10 MWT). Clinicians and researchers can be confident that changes above the SRD95s for the different patient groups, for both sexes and with regard to weight-bearing status represent a real clinical change in rehabilitation process.

  13. Reliability of neural encoding

    DEFF Research Database (Denmark)

    Alstrøm, Preben; Beierholm, Ulrik; Nielsen, Carsten Dahl

    2002-01-01

    The reliability with which a neuron is able to create the same firing pattern when presented with the same stimulus is of critical importance to the understanding of neuronal information processing. We show that reliability is closely related to the process of phaselocking. Experimental results f...

  14. Reliability and optimization of structural systems

    International Nuclear Information System (INIS)

    Thoft-Christensen, P.

    1987-01-01

    The proceedings contain 28 papers presented at the 1st working conference. The working conference was organized by the IFIP Working Group 7.5. The proceedings also include 4 papers which were submitted, but for various reasons not presented at the working conference. The working conference was attended by 50 participants from 18 countries. The conference was the first scientific meeting of the new IFIP Working Group 7.5 on 'Reliability and Optimization of Structural Systems'. The purpose of the Working Group 7.5 is to promote modern structural system optimization and reliability theory, to advance international cooperation in the field of structural system optimization and reliability theory, to stimulate research, development and application of structural system optimization and reliability theory, to further the dissemination and exchange of information on reliability and optimization of structural system optimization and reliability theory, and to encourage education in structural system optimization and reliability theory. (orig./HP)

  15. Optimization of Reliability Centered Maintenance Bassed on Maintenance Costs and Reliability with Consideration of Location of Components

    Directory of Open Access Journals (Sweden)

    Mahdi Karbasian

    2011-03-01

    Full Text Available The reliability of designing systems such as electrical and electronic circuits, power generation/ distribution networks and mechanical systems, in which the failure of a component may cause the whole system failure, and even the reliability of cellular manufacturing systems that their machines are connected to as series are critically important. So far approaches for improving the reliability of these systems have been mainly based on the enhancement of inherent reliability of any system component or increasing system reliability based on maintenance strategies. Also in some of the resources, only the influence of the location of systems' components on reliability is studied. Therefore, it seems other approaches have been rarely applied. In this paper, a multi criteria model has been proposed to perform a balance among a system's reliability, location costs, and its system maintenance. Finally, a numerical example has been presented and solved by the Lingo software.

  16. Fuel reliability experience in Finland

    International Nuclear Information System (INIS)

    Kekkonen, L.

    2015-01-01

    Four nuclear reactors have operated in Finland now for 35-38 years. The two VVER-440 units at Loviisa Nuclear Power Plant are operated by Fortum and two BWR’s in Olkiluoto are operated by Teollisuuden Voima Oyj (TVO). The fuel reliability experience of the four reactors operating currently in Finland has been very good and the fuel failure rates have been very low. Systematic inspection of spent fuel assemblies, and especially all failed assemblies, is a good practice that is employed in Finland in order to improve fuel reliability and operational safety. Investigation of the root cause of fuel failures is important in developing ways to prevent similar failures in the future. The operational and fuel reliability experience at the Loviisa Nuclear Power Plant has been reported also earlier in the international seminars on WWER Fuel Performance, Modelling and Experimental Support. In this paper the information on fuel reliability experience at Loviisa NPP is updated and also a short summary of the fuel reliability experience at Olkiluoto NPP is given. Keywords: VVER-440, fuel reliability, operational experience, poolside inspections, fuel failure identification. (author)

  17. Reliability and maintainability

    International Nuclear Information System (INIS)

    1994-01-01

    Several communications in this conference are concerned with nuclear plant reliability and maintainability; their titles are: maintenance optimization of stand-by Diesels of 900 MW nuclear power plants; CLAIRE: an event-based simulation tool for software testing; reliability as one important issue within the periodic safety review of nuclear power plants; design of nuclear building ventilation by the means of functional analysis; operation characteristic analysis for a power industry plant park, as a function of influence parameters

  18. THE IMPACT OF INVESTMENTS, EXPORTS, AND OPENNESS ON ECONOMIC GROWTH. A COMPARATIVE STUDY ON THE EAST EUROPEAN COUNTRIES

    Directory of Open Access Journals (Sweden)

    Simuţ Ramona

    2012-12-01

    Full Text Available The study of the economic growth process has older implications. The preoccupation for the study of the economic growth has existed beginning with the representatives of the Classical School and continuing with the Keynesians, Neokeynesians, and Neoclassics. A series of empirical studies have tested the correlation between the dynamics of the different factors and the process of economic growth. \\r\

  19. RTE - 2015 Reliability Report. Summary

    International Nuclear Information System (INIS)

    2016-01-01

    Every year, RTE produces a reliability report for the past year. This report includes a number of results from previous years so that year-to-year comparisons can be drawn and long-term trends analysed. The 2015 report underlines the major factors that have impacted on the reliability of the electrical power system, without focusing exclusively on Significant System Events (ESS). It describes various factors which contribute to present and future reliability and the numerous actions implemented by RTE to ensure reliability today and in the future, as well as the ways in which the various parties involved in the electrical power system interact across the whole European interconnected network

  20. Use of an oxygen concentrator in a Nigerian neonatal unit: economic implications and reliability.

    Science.gov (United States)

    Mokuolu, Olugbenga A; Ajayi, Oluade A

    2002-09-01

    A 3-year experience of using an oxygen concentrator in a Nigerian newborn unit and economic appraisal of its effectiveness is reported. The oxygen concentrator is a device that absorbs nitrogen from ambient air, with a resultant oxygen concentration of 85 to 95% at different flow rates. The oxygen concentrator met our oxygen needs which averaged 18 hours a day, and had a huge cost advantage over the oxygen cylinders. The cost of oxygen via cylinder for just one patient for a year exceeds the initial capital outlay for a concentrator. The Puritan-Bennett oxygen concentrator has a lifespan of at least 7 years and is virtually maintenance-free for the 1st 26,400 hours of use, after which some major components might need replacement. We conclude that in developing countries oxygen concentrators are a more cost-effective, reliable and convenient means of oxygen supply than oxygen cylinders, and recommend their use where there is a high demand for oxygen.