The impact of scheduling on service reliability : Trip-time determination and holding points in long-headway services

NARCIS (Netherlands)

Van Oort, N.; Boterman, J.W.; Van Nes, R.

2012-01-01

This paper presents research on optimizing service reliability of longheadway services in urban public transport. Setting the driving time, and thus the departure time at stops, is an important decision when optimizing reliability in urban public transport. The choice of the percentile out of

Novel approach for evaluation of service reliability for electricity customers

Institute of Scientific and Technical Information of China (English)

JIANG; John; N

2009-01-01

Understanding reliability value for electricity customer is important to market-based reliability management. This paper proposes a novel approach to evaluate the reliability for electricity customers by using indifference curve between economic compensation for power interruption and service reliability of electricity. Indifference curve is formed by calculating different planning schemes of network expansion for different reliability requirements of customers, which reveals the information about economic values for different reliability levels for electricity customers, so that the reliability based on market supply demand mechanism can be established and economic signals can be provided for reliability management and enhancement.

Differentiated protection services with failure probability guarantee for workflow-based applications

Science.gov (United States)

Zhong, Yaoquan; Guo, Wei; Jin, Yaohui; Sun, Weiqiang; Hu, Weisheng

2010-12-01

A cost-effective and service-differentiated provisioning strategy is very desirable to service providers so that they can offer users satisfactory services, while optimizing network resource allocation. Providing differentiated protection services to connections for surviving link failure has been extensively studied in recent years. However, the differentiated protection services for workflow-based applications, which consist of many interdependent tasks, have scarcely been studied. This paper investigates the problem of providing differentiated services for workflow-based applications in optical grid. In this paper, we develop three differentiated protection services provisioning strategies which can provide security level guarantee and network-resource optimization for workflow-based applications. The simulation demonstrates that these heuristic algorithms provide protection cost-effectively while satisfying the applications' failure probability requirements.

Reliability in individual monitoring service.

Science.gov (United States)

Mod Ali, N

2011-03-01

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

Assessing the Impact of Imperfect Diagnosis on Service Reliability

DEFF Research Database (Denmark)

Grønbæk, Lars Jesper; Schwefel, Hans-Peter; Kjærgaard, Jens Kristian

2010-01-01

, representative diagnosis performance metrics have been defined and their closed-form solutions obtained for the Markov model. These equations enable model parameterization from traces of implemented diagnosis components. The diagnosis model has been integrated in a reliability model assessing the impact...... of the diagnosis functions for the studied reliability problem. In a simulation study we finally analyze trade-off properties of diagnosis heuristics from literature, map them to the analytic Markov model, and investigate its suitability for service reliability optimization....

Service differentiation in spare parts inventory management

NARCIS (Netherlands)

Kranenburg, A.A.; Houtum, van G.J.J.A.N.

2008-01-01

The contemporary after-sales market is of increasing importance. One of the features required by the market is to provide differentiated service levels to different groups of customers. We use critical levels as a means to offer differentiation. Critical level policies aim to exploit the differences

Reliability and service life of wood structures and buildings

Directory of Open Access Journals (Sweden)

Zdeňka Havířová

2005-01-01

Full Text Available Service life of constructions and buildings of wood is dependent on temperature and moisture conditions in layers of the building cladding where the wood framework is built in. Temperature/moisture conditions or the corresponding equilibrium moisture content (EMC of the construction show considerable effects on the functional reliability of the whole building from the viewpoint of mechanical resistance and stability (ER1, energy savings and thermal protection (ER6 and hygiene, health and environment protection (ER3. To ensure the reliability of constructions and buildings for the period of their supposed service life a more profound analysis of constructions is necessary from the aspect of a global thermal/technical evaluation.

A Novel Analytic Technique for the Service Station Reliability in a Discrete-Time Repairable Queue

Directory of Open Access Journals (Sweden)

Renbin Liu

2013-01-01

Full Text Available This paper presents a decomposition technique for the service station reliability in a discrete-time repairable GeomX/G/1 queueing system, in which the server takes exhaustive service and multiple adaptive delayed vacation discipline. Using such a novel analytic technique, some important reliability indices and reliability relation equations of the service station are derived. Furthermore, the structures of the service station indices are also found. Finally, special cases and numerical examples validate the derived results and show that our analytic technique is applicable to reliability analysis of some complex discrete-time repairable bulk arrival queueing systems.

Reliability analysis of service water system under earthquake

International Nuclear Information System (INIS)

Yu Yu; Qian Xiaoming; Lu Xuefeng; Wang Shengfei; Niu Fenglei

2013-01-01

Service water system is one of the important safety systems in nuclear power plant, whose failure probability is always gained by system reliability analysis. The probability of equipment failure under the earthquake is the function of the peak acceleration of earthquake motion, while the occurrence of earthquake is of randomicity, thus the traditional fault tree method in current probability safety assessment is not powerful enough to deal with such case of conditional probability problem. An analysis frame was put forward for system reliability evaluation in seismic condition in this paper, in which Monte Carlo simulation was used to deal with conditional probability problem. Annual failure probability of service water system was calculated, and failure probability of 1.46X10 -4 per year was obtained. The analysis result is in accordance with the data which indicate equipment seismic resistance capability, and the rationality of the model is validated. (authors)

A Fast Optimization Method for Reliability and Performance of Cloud Services Composition Application

Directory of Open Access Journals (Sweden)

Zhao Wu

2013-01-01

Full Text Available At present the cloud computing is one of the newest trends of distributed computation, which is propelling another important revolution of software industry. The cloud services composition is one of the key techniques in software development. The optimization for reliability and performance of cloud services composition application, which is a typical stochastic optimization problem, is confronted with severe challenges due to its randomness and long transaction, as well as the characteristics of the cloud computing resources such as openness and dynamic. The traditional reliability and performance optimization techniques, for example, Markov model and state space analysis and so forth, have some defects such as being too time consuming and easy to cause state space explosion and unsatisfied the assumptions of component execution independence. To overcome these defects, we propose a fast optimization method for reliability and performance of cloud services composition application based on universal generating function and genetic algorithm in this paper. At first, a reliability and performance model for cloud service composition application based on the multiple state system theory is presented. Then the reliability and performance definition based on universal generating function is proposed. Based on this, a fast reliability and performance optimization algorithm is presented. In the end, the illustrative examples are given.

Service Differentiation in Residential Broadband Networks

DEFF Research Database (Denmark)

Sigurdsson, Halldór Matthias

2004-01-01

As broadband gains widespread adoption with residential users, revenue generating voice- and video-services have not yet taken off. This slow uptake is often attributed to lack of Quality of Service management in residential broadband networks. To resolve this and induce service variety, network...... access providers are implementing service differentiation in their networks where voice and video gets prioritised before data. This paper discusses the role of network access providers in multipurpose packet based networks and the available migration strategies for supporting multimedia services...... in digital subscriber line (DSL) based residential broadband networks. Four possible implementation scenarios and their technical characteristics and effects are described. To conclude, the paper discusses how network access providers can be induced to open their networks for third party service providers....

Reliability analysis of the service water system of Angra 1 reactor

International Nuclear Information System (INIS)

Tayt-Sohn, L.C.; Oliveira, L.F.S. de.

1984-01-01

A reliability analysis of the service water system is done aiming to use in the evaluation of the non reliability of the Component Cooling System (SRC) for great loss of cooling accidents in nuclear power plants. (E.G.) [pt

Reliability analysis of the service water system of Angra 1 reactor

International Nuclear Information System (INIS)

Oliveira, L.F.S. de; Fleming, P.V.; Frutuoso e Melo, P.F.F.; Tayt-Sohn, L.C.

1983-01-01

A reliability analysis of the service water system is done aiming to use in the evaluation of the non reliability of the component cooling system (SRC) for great loss of cooling accidents in nuclear power plants. (E.G.) [pt

Reliability of piping system components. Framework for estimating failure parameters from service data

International Nuclear Information System (INIS)

Nyman, R.; Hegedus, D.; Tomic, B.; Lydell, B.

1997-12-01

This report summarizes results and insights from the final phase of a R and D project on piping reliability sponsored by the Swedish Nuclear Power Inspectorate (SKI). The technical scope includes the development of an analysis framework for estimating piping reliability parameters from service data. The R and D has produced a large database on the operating experience with piping systems in commercial nuclear power plants worldwide. It covers the period 1970 to the present. The scope of the work emphasized pipe failures (i.e., flaws/cracks, leaks and ruptures) in light water reactors (LWRs). Pipe failures are rare events. A data reduction format was developed to ensure that homogenous data sets are prepared from scarce service data. This data reduction format distinguishes between reliability attributes and reliability influence factors. The quantitative results of the analysis of service data are in the form of conditional probabilities of pipe rupture given failures (flaws/cracks, leaks or ruptures) and frequencies of pipe failures. Finally, the R and D by SKI produced an analysis framework in support of practical applications of service data in PSA. This, multi-purpose framework, termed 'PFCA'-Pipe Failure Cause and Attribute- defines minimum requirements on piping reliability analysis. The application of service data should reflect the requirements of an application. Together with raw data summaries, this analysis framework enables the development of a prior and a posterior pipe rupture probability distribution. The framework supports LOCA frequency estimation, steam line break frequency estimation, as well as the development of strategies for optimized in-service inspection strategies

Reliability of piping system components. Framework for estimating failure parameters from service data

Energy Technology Data Exchange (ETDEWEB)

Nyman, R [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Hegedus, D; Tomic, B [ENCONET Consulting GesmbH, Vienna (Austria); Lydell, B [RSA Technologies, Vista, CA (United States)

1997-12-01

This report summarizes results and insights from the final phase of a R and D project on piping reliability sponsored by the Swedish Nuclear Power Inspectorate (SKI). The technical scope includes the development of an analysis framework for estimating piping reliability parameters from service data. The R and D has produced a large database on the operating experience with piping systems in commercial nuclear power plants worldwide. It covers the period 1970 to the present. The scope of the work emphasized pipe failures (i.e., flaws/cracks, leaks and ruptures) in light water reactors (LWRs). Pipe failures are rare events. A data reduction format was developed to ensure that homogenous data sets are prepared from scarce service data. This data reduction format distinguishes between reliability attributes and reliability influence factors. The quantitative results of the analysis of service data are in the form of conditional probabilities of pipe rupture given failures (flaws/cracks, leaks or ruptures) and frequencies of pipe failures. Finally, the R and D by SKI produced an analysis framework in support of practical applications of service data in PSA. This, multi-purpose framework, termed `PFCA`-Pipe Failure Cause and Attribute- defines minimum requirements on piping reliability analysis. The application of service data should reflect the requirements of an application. Together with raw data summaries, this analysis framework enables the development of a prior and a posterior pipe rupture probability distribution. The framework supports LOCA frequency estimation, steam line break frequency estimation, as well as the development of strategies for optimized in-service inspection strategies. 63 refs, 30 tabs, 22 figs.

Quantifying the Quality of Service of Streaming Media in Differentiated Services Networks

NARCIS (Netherlands)

Agrawal, D.K.; Kleiberg, T.; Papp, S.; Kooij, R.E.; Van Mieghem, P.

2007-01-01

Quality of Service (QoS) support in the current internet is indispensable because of QoS-sensitive real-time applications such as Voice-over-IP, IP-TV, video conferencing, online gaming etc. Since the introduction of the Differentiated Services (Diff-Serv) architecture there has been considerable

Quantifying the quality of service of streaming media in differentiated services networks

NARCIS (Netherlands)

Agrawal, D.K.; Kleiberg, T.; Papp, S.; Kooij, R.E.; Mieghem, P. van

2007-01-01

Quality of Service (QoS) support in the current internet is indispensable because of QoS-sensitive real-time applications such as Voice-over-IP, IP-TV, video conferencing, online gaming etc. Since the introduction of the Differentiated Services (Diff-Serv) architecture there has been considerable

Reliability theory for repair service organization simulation and increase of innovative attraction of industrial enterprises

Science.gov (United States)

Dolzhenkova, E. V.; Iurieva, L. V.

2018-05-01

The study presents the author's algorithm for the industrial enterprise repair service organization simulation based on the reliability theory, as well as the results of its application. The monitoring of the industrial enterprise repair service organization is proposed to perform on the basis of the enterprise's state indexes for the main resources (equipment, labour, finances, repair areas), which allows quantitative evaluation of the reliability level as a resulting summary rating of the said parameters and the ensuring of an appropriate level of the operation reliability of the serviced technical objects. Under the conditions of the tough competition, the following approach is advisable: the higher efficiency of production and a repair service itself, the higher the innovative attractiveness of an industrial enterprise. The results of the calculations show that in order to prevent inefficient losses of production and to reduce the repair costs, it is advisable to apply the reliability theory. The overall reliability rating calculated on the basis of the author's algorithm has low values. The processing of the statistical data forms the reliability characteristics for the different workshops and services of an industrial enterprise, which allows one to define the failure rates of the various units of equipment and to establish the reliability indexes necessary for the subsequent mathematical simulation. The proposed simulating algorithm contributes to an increase of the efficiency of the repair service organization and improvement of the innovative attraction of an industrial enterprise.

Reliable differentiation of Meyerozyma guilliermondii from Meyerozyma caribbica by internal transcribed spacer restriction fingerprinting.

Science.gov (United States)

Romi, Wahengbam; Keisam, Santosh; Ahmed, Giasuddin; Jeyaram, Kumaraswamy

2014-02-28

Meyerozyma guilliermondii (anamorph Candida guilliermondii) and Meyerozyma caribbica (anamorph Candida fermentati) are closely related species of the genetically heterogenous M. guilliermondii complex. Conventional phenotypic methods frequently misidentify the species within this complex and also with other species of the Saccharomycotina CTG clade. Even the long-established sequencing of large subunit (LSU) rRNA gene remains ambiguous. We also faced similar problem during identification of yeast isolates of M. guilliermondii complex from indigenous bamboo shoot fermentation in North East India. There is a need for development of reliable and accurate identification methods for these closely related species because of their increasing importance as emerging infectious yeasts and associated biotechnological attributes. We targeted the highly variable internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) and identified seven restriction enzymes through in silico analysis for differentiating M. guilliermondii from M. caribbica. Fifty five isolates of M. guilliermondii complex which could not be delineated into species-specific taxonomic ranks by API 20 C AUX and LSU rRNA gene D1/D2 sequencing were subjected to ITS-restriction fragment length polymorphism (ITS-RFLP) analysis. TaqI ITS-RFLP distinctly differentiated the isolates into M. guilliermondii (47 isolates) and M. caribbica (08 isolates) with reproducible species-specific patterns similar to the in silico prediction. The reliability of this method was validated by ITS1-5.8S-ITS2 sequencing, mitochondrial DNA RFLP and electrophoretic karyotyping. We herein described a reliable ITS-RFLP method for distinct differentiation of frequently misidentified M. guilliermondii from M. caribbica. Even though in silico analysis differentiated other closely related species of M. guilliermondii complex from the above two species, it is yet to be confirmed by in vitro analysis using reference strains. This method can be used

Reliable execution based on CPN and skyline optimization for Web service composition.

Science.gov (United States)

Chen, Liping; Ha, Weitao; Zhang, Guojun

2013-01-01

With development of SOA, the complex problem can be solved by combining available individual services and ordering them to best suit user's requirements. Web services composition is widely used in business environment. With the features of inherent autonomy and heterogeneity for component web services, it is difficult to predict the behavior of the overall composite service. Therefore, transactional properties and nonfunctional quality of service (QoS) properties are crucial for selecting the web services to take part in the composition. Transactional properties ensure reliability of composite Web service, and QoS properties can identify the best candidate web services from a set of functionally equivalent services. In this paper we define a Colored Petri Net (CPN) model which involves transactional properties of web services in the composition process. To ensure reliable and correct execution, unfolding processes of the CPN are followed. The execution of transactional composition Web service (TCWS) is formalized by CPN properties. To identify the best services of QoS properties from candidate service sets formed in the TCSW-CPN, we use skyline computation to retrieve dominant Web service. It can overcome that the reduction of individual scores to an overall similarity leads to significant information loss. We evaluate our approach experimentally using both real and synthetically generated datasets.

Service Degradation in Context Management Frameworks

DEFF Research Database (Denmark)

Shawky, Ahmed; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

2011-01-01

information. The paper considers a developed framework from the ICT project, OPEN, and investigates the impact of applying Differentiated Services (DiffServ) Quality of Services (QoS). The paper finally provides insight in how the insight gained can be utilized to ensure reliable remote accessed context......Context aware network services are a new and inter-esting way to enhance network users experience. A context aware application/service enhances network performance in relation to dynamic context information, e.g. mobility, location and device information as it senses and reacts to environment...... changes. The reliability of the information accessed is a key factor in achieving reliable context aware application. This paper will review the service degradation in Context Management Frameworks (CMF) and the effect of high network utilization, with particular focus on the reliability of the accessed...

Differential private collaborative Web services QoS prediction

KAUST Repository

Liu, An

2018-04-04

Collaborative Web services QoS prediction has proved to be an important tool to estimate accurately personalized QoS experienced by individual users, which is beneficial for a variety of operations in the service ecosystem, such as service selection, composition and recommendation. While a number of achievements have been attained on the study of improving the accuracy of collaborative QoS prediction, little work has been done for protecting user privacy in this process. In this paper, we propose a privacy-preserving collaborative QoS prediction framework which can protect the private data of users while retaining the ability of generating accurate QoS prediction. We introduce differential privacy, a rigorous and provable privacy model, into the process of collaborative QoS prediction. We first present DPS, a method that disguises a user’s observed QoS values by applying differential privacy to the user’s QoS data directly. We show how to integrate DPS with two representative collaborative QoS prediction approaches. To improve the utility of the disguised QoS data, we present DPA, another QoS disguising method which first aggregates a user’s QoS data before adding noise to achieve differential privacy. We evaluate the proposed methods by conducting extensive experiments on a real world Web services QoS dataset. Experimental results show our approach is feasible in practice.

Differential private collaborative Web services QoS prediction

KAUST Repository

Liu, An; Shen, Xindi; Li, Zhixu; Liu, Guanfeng; Xu, Jiajie; Zhao, Lei; Zheng, Kai; Shang, Shuo

2018-01-01

Collaborative Web services QoS prediction has proved to be an important tool to estimate accurately personalized QoS experienced by individual users, which is beneficial for a variety of operations in the service ecosystem, such as service selection, composition and recommendation. While a number of achievements have been attained on the study of improving the accuracy of collaborative QoS prediction, little work has been done for protecting user privacy in this process. In this paper, we propose a privacy-preserving collaborative QoS prediction framework which can protect the private data of users while retaining the ability of generating accurate QoS prediction. We introduce differential privacy, a rigorous and provable privacy model, into the process of collaborative QoS prediction. We first present DPS, a method that disguises a user’s observed QoS values by applying differential privacy to the user’s QoS data directly. We show how to integrate DPS with two representative collaborative QoS prediction approaches. To improve the utility of the disguised QoS data, we present DPA, another QoS disguising method which first aggregates a user’s QoS data before adding noise to achieve differential privacy. We evaluate the proposed methods by conducting extensive experiments on a real world Web services QoS dataset. Experimental results show our approach is feasible in practice.

Is there a relationship between service integration and differentiation and patient outcomes?

Directory of Open Access Journals (Sweden)

Robin P. Newhouse

2003-11-01

Full Text Available Objective: To examine the level of service integration within Maryland hospitals and service differentiation across the hospital system or network and its affect on heart failure patient clinical and economic outcomes. Data sources/Study setting: Maryland Health Services Cost Review Commission Inpatient Data for 1997 and 1998 were used for secondary data analysis. Study design: Retrospective cross sectional. Independent variables were the level of service integration and differentiation created from the 1998 American Hospital Association Annual Survey based on the work of Bazzoli et al. [1]. The primary dependent variables were readmission, in-hospital mortality, length of stay and costs. Data collection/Extraction methods: Patients discharged from Maryland hospitals with a diagnosis that grouped to DRG 127 (heart failure were extracted. Multivariate linear and logistic models clustered by hospital were used to analyse results at the patient level. Principal findings: A higher likelihood of readmission was found as the level of Community Differentiation increased. Although costs were higher as Total Differentiation increased in 1998, these results were not validated by 1997 data. No significant relationship was found between integration of services and outcomes. Conclusions: Similar outcomes were achieved regardless of the level of service integration or differentiation. Community hospitals produce similar patient outcomes at the same cost for this diagnosis.

Reliability assessment of serviceability performance of braced retaining walls using a neural network approach

Science.gov (United States)

Goh, A. T. C.; Kulhawy, F. H.

2005-05-01

In urban environments, one major concern with deep excavations in soft clay is the potentially large ground deformations in and around the excavation. Excessive movements can damage adjacent buildings and utilities. There are many uncertainties associated with the calculation of the ultimate or serviceability performance of a braced excavation system. These include the variabilities of the loadings, geotechnical soil properties, and engineering and geometrical properties of the wall. A risk-based approach to serviceability performance failure is necessary to incorporate systematically the uncertainties associated with the various design parameters. This paper demonstrates the use of an integrated neural network-reliability method to assess the risk of serviceability failure through the calculation of the reliability index. By first performing a series of parametric studies using the finite element method and then approximating the non-linear limit state surface (the boundary separating the safe and failure domains) through a neural network model, the reliability index can be determined with the aid of a spreadsheet. Two illustrative examples are presented to show how the serviceability performance for braced excavation problems can be assessed using the reliability index.

Estimated Value of Service Reliability for Electric Utility Customers in the United States

Energy Technology Data Exchange (ETDEWEB)

Sullivan, M.J.; Mercurio, Matthew; Schellenberg, Josh

2009-06-01

Information on the value of reliable electricity service can be used to assess the economic efficiency of investments in generation, transmission and distribution systems, to strategically target investments to customer segments that receive the most benefit from system improvements, and to numerically quantify the risk associated with different operating, planning and investment strategies. This paper summarizes research designed to provide estimates of the value of service reliability for electricity customers in the US. These estimates were obtained by analyzing the results from 28 customer value of service reliability studies conducted by 10 major US electric utilities over the 16 year period from 1989 to 2005. Because these studies used nearly identical interruption cost estimation or willingness-to-pay/accept methods it was possible to integrate their results into a single meta-database describing the value of electric service reliability observed in all of them. Once the datasets from the various studies were combined, a two-part regression model was used to estimate customer damage functions that can be generally applied to calculate customer interruption costs per event by season, time of day, day of week, and geographical regions within the US for industrial, commercial, and residential customers. Estimated interruption costs for different types of customers and of different duration are provided. Finally, additional research and development designed to expand the usefulness of this powerful database and analysis are suggested.

Reliability Evaluation of Service-Oriented Architecture Systems Considering Fault-Tolerance Designs

Directory of Open Access Journals (Sweden)

Kuan-Li Peng

2014-01-01

strategies. Sensitivity analysis of SOA at both coarse and fine grain levels is also studied, which can be used to efficiently identify the critical parts within the system. Two SOA system scenarios based on real industrial practices are studied. Experimental results show that the proposed SOA model can be used to accurately depict the behavior of SOA systems. Additionally, a sensitivity analysis that quantizes the effects of system structure as well as fault tolerance on the overall reliability is also studied. On the whole, the proposed reliability modeling and analysis framework may help the SOA system service provider to evaluate the overall system reliability effectively and also make smarter improvement plans by focusing resources on enhancing reliability-sensitive parts within the system.

Effects of Differential Item Functioning on Examinees' Test Performance and Reliability of Test

Science.gov (United States)

Lee, Yi-Hsuan; Zhang, Jinming

2017-01-01

Simulations were conducted to examine the effect of differential item functioning (DIF) on measurement consequences such as total scores, item response theory (IRT) ability estimates, and test reliability in terms of the ratio of true-score variance to observed-score variance and the standard error of estimation for the IRT ability parameter. The…

Reliability analysis of structures under periodic proof tests in service

Science.gov (United States)

Yang, J.-N.

1976-01-01

A reliability analysis of structures subjected to random service loads and periodic proof tests treats gust loads and maneuver loads as random processes. Crack initiation, crack propagation, and strength degradation are treated as the fatigue process. The time to fatigue crack initiation and ultimate strength are random variables. Residual strength decreases during crack propagation, so that failure rate increases with time. When a structure fails under periodic proof testing, a new structure is built and proof-tested. The probability of structural failure in service is derived from treatment of all the random variables, strength degradations, service loads, proof tests, and the renewal of failed structures. Some numerical examples are worked out.

Verification criteria on the reliability of personal dosimetric services from x and gamma radiations

International Nuclear Information System (INIS)

Borasi, G.; Benco, A.; Kaftal, S.

1990-07-01

The paper presents the methods used by Working Group ENEA-EDP (Experts in Personal Dosimetry) to control the reliability of the Dosimetric Services operating in Italy and asking for the above controls on voluntary basis. Testing and irradiation test methods are explained as well as the evaluation criteria. The paper includes suggestions and guide-lines to gain the status of 'Reliable Service'. Technical equipment and operating procedures needed to pass the test are also illustrated. (author)

The selective use of emergency shipments for service-contract differentiation

NARCIS (Netherlands)

Alvarez, Elisa; van der Heijden, Matthijs C.; Zijm, Willem H.M.

2013-01-01

Suppliers of capital goods increasingly offer performance-based service contracts with customer-specific service levels. We use selective emergency shipments of spare parts to differentiate logistic performance: We apply emergency shipments in out-of-stock situations for combinations of parts and

Reliability-based service life assessment of concrete structures in nuclear power plants: optimum inspection and repair

International Nuclear Information System (INIS)

Ellingwood, B.R.; Mori, Y.

1995-01-01

Research is being conducted to address aging management of safety-related reinforced concrete structures in nuclear power plants (NPPs). Documentation is being prepared to identify potential structural safety issues and to recommend criteria for use in evaluating reinforced concrete structures for continued service. Time-dependent reliability analysis provides the framework and quantitative tools for the condition assessment. The role of in-service inspection and repair in ensuring continued reliability in-service is examined. (author). 19 refs., 4 figs

Evaluation and improvement in nondestructive examination (NDE) reliability for in-service inspection of light water reactors

International Nuclear Information System (INIS)

Deffenbaugh, J.D.; Good, M.S.; Green, E.R.; Heasler, P.G.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.

1988-01-01

The evaluation and improvement of NDE Reliability for In-service Inspection (ISI) of Light Water Reactors (NDE Reliability) Program at Pacific Northwest Laboratory (PNL) was established to determine the reliability of current ISI techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this NRC program are to: determine the reliability of ultrasonic ISI performed on commercial light-water reactor (LWR) primary systems; determine the impact of NDE unreliability on system safety and determine the level of inspection reliability required to ensure a suitably low failure probability using probabilistic fracture mechanics analysis; evaluate the degree of reliability improvement that could be achieved using improved and advanced NDE technique; and recommend revisions to ASME Code, Section XI, and Regulatory Requirements, based on material properties, service conditions, and NDE uncertainties, that will ensure suitably low failure probabilities. The program consists of three basic tasks: a Piping task, a Pressure Vessel task, and an Evaluation and Improvement in NDE Reliability task. The major efforts were concentrated in the Piping task and the Evaluation and Improvement in NDE Reliability task

Simulation of logical traffic isolation using differentiated services

CSIR Research Space (South Africa)

Dlamini, I

2009-06-01

Full Text Available This paper extends work on a forensic model for traffic isolation based on Differentiated Services (DiffServ) and measures its performance by using a simulation. The simulated model has four basic components: traffic generators, the DiffServ network...

Reliability of buildings in service limit state for maximum horizontal displacements

Directory of Open Access Journals (Sweden)

A. G. B. Corelhano

Full Text Available Brazilian design code ABNT NBR6118:2003 - Design of Concrete Structures - Procedures - [1] proposes the use of simplified models for the consideration of non-linear material behavior in the evaluation of horizontal displacements in buildings. These models penalize stiffness of columns and beams, representing the effects of concrete cracking and avoiding costly physical non-linear analyses. The objectives of the present paper are to investigate the accuracy and uncertainty of these simplified models, as well as to evaluate the reliabilities of structures designed following ABNT NBR6118:2003[1&] in the service limit state for horizontal displacements. Model error statistics are obtained from 42 representative plane frames. The reliabilities of three typical (4, 8 and 12 floor buildings are evaluated, using the simplified models and a rigorous, physical and geometrical non-linear analysis. Results show that the 70/70 (column/beam stiffness reduction model is more accurate and less conservative than the 80/40 model. Results also show that ABNT NBR6118:2003 [1] design criteria for horizontal displacement limit states (masonry damage according to ACI 435.3R-68(1984 [10] are conservative, and result in reliability indexes which are larger than those recommended in EUROCODE [2] for irreversible service limit states.

Reliability and service life of wood structures and buildings

OpenAIRE

Zdeňka Havířová; Pavel Kubů

2005-01-01

Service life of constructions and buildings of wood is dependent on temperature and moisture conditions in layers of the building cladding where the wood framework is built in. Temperature/moisture conditions or the corresponding equilibrium moisture content (EMC) of the construction show considerable effects on the functional reliability of the whole building from the viewpoint of mechanical resistance and stability (ER1), energy savings and thermal protection (ER6) and hygiene, health and e...

Beliefs concerning the reliability of nuclear power plant in-service inspections

International Nuclear Information System (INIS)

Kettunen, J.

1997-01-01

The aim of the study was to investigate belief systems held by the officials responsible for the planning and supervision of NDT operations within the Finnish nuclear industry. They were asked to express their opinions on (1) the reliability of NDT methods in general, (2) the factors influencing the reliability of in-service inspections, and (3) the degree of reliability of the current inspections operations conducted by means of NDT methods in the Finnish nuclear power plants. Another goal of the study was to assess the adequacy of officials' beliefs (or belief systems). The research data was collected by interviewing representatives from Finnish power companies (Imatran Voima Oy and Teollisuuden Voima Oy), independent inspection organisations, and the Finnish Centre for Radiation and Nuclear Safety (STUK). The adequacy of the beliefs expressed was assessed by means of the results obtained from international NDT reliability studies and on the basis of interviewees' own justification. (refs.)

Modeling Message Queueing Services with Reliability Guarantee in Cloud Computing Environment Using Colored Petri Nets

Directory of Open Access Journals (Sweden)

Jing Li

2015-01-01

Full Text Available Motivated by the need for loosely coupled and asynchronous dissemination of information, message queues are widely used in large-scale application areas. With the advent of virtualization technology, cloud-based message queueing services (CMQSs with distributed computing and storage are widely adopted to improve availability, scalability, and reliability; however, a critical issue is its performance and the quality of service (QoS. While numerous approaches evaluating system performance are available, there is no modeling approach for estimating and analyzing the performance of CMQSs. In this paper, we employ both the analytical and simulation modeling to address the performance of CMQSs with reliability guarantee. We present a visibility-based modeling approach (VMA for simulation model using colored Petri nets (CPN. Our model incorporates the important features of message queueing services in the cloud such as replication, message consistency, resource virtualization, and especially the mechanism named visibility timeout which is adopted in the services to guarantee system reliability. Finally, we evaluate our model through different experiments under varied scenarios to obtain important performance metrics such as total message delivery time, waiting number, and components utilization. Our results reveal considerable insights into resource scheduling and system configuration for service providers to estimate and gain performance optimization.

The Effect of Instrument-Specific Rater Training on Interrater Reliability and Counseling Skills Performance Differentiation

Science.gov (United States)

Meacham, Paul Douglas, Jr.

2013-01-01

The purpose of this study was to explore the effect of instrument-specific rater training on interrater reliability (IRR) and counseling skills performance differentiation. Strong IRR is of primary concern to effective program evaluation (McCullough, Kuhn, Andrews, Valen, Hatch, & Osimo, 2003; Schanche, Nielsen, McCullough, Valen, &…

Dynamic RACH Partition for Massive Access of Differentiated M2M Services

Directory of Open Access Journals (Sweden)

Qinghe Du

2016-03-01

Full Text Available In machine-to-machine (M2M networks, a key challenge is to overcome the overload problem caused by random access requests from massive machine-type communication (MTC devices. When differentiated services coexist, such as delay-sensitive and delay-tolerant services, the problem becomes more complicated and challenging. This is because delay-sensitive services often use more aggressive policies, and thus, delay-tolerant services get much fewer chances to access the network. To conquer the problem, we propose an efficient mechanism for massive access control over differentiated M2M services, including delay-sensitive and delay-tolerant services. Specifically, based on the traffic loads of the two types of services, the proposed scheme dynamically partitions and allocates the random access channel (RACH resource to each type of services. The RACH partition strategy is thoroughly optimized to increase the access performances of M2M networks. Analyses and simulation demonstrate the effectiveness of our design. The proposed scheme can outperform the baseline access class barring (ACB scheme, which ignores service types in access control, in terms of access success probability and the average access delay.

Toward Real-time Multi-criteria Decision Making for Bus Service Reliability Optimisation

DEFF Research Database (Denmark)

Tran, Vu The; Eklund, Peter; Cook, Chris

2015-01-01

factors (such as traffic congestion and bad weather) in high frequency transit operations often cause irregular headway that can result in decreased service reliability. The approach proposed in this paper, which has the capability of handling the uncertainty of transit operations based on Multi...

Analysis and Optimization of Sparse Random Linear Network Coding for Reliable Multicast Services

DEFF Research Database (Denmark)

Tassi, Andrea; Chatzigeorgiou, Ioannis; Roetter, Daniel Enrique Lucani

2016-01-01

Point-to-multipoint communications are expected to play a pivotal role in next-generation networks. This paper refers to a cellular system transmitting layered multicast services to a multicast group of users. Reliability of communications is ensured via different random linear network coding (RLNC......) techniques. We deal with a fundamental problem: the computational complexity of the RLNC decoder. The higher the number of decoding operations is, the more the user's computational overhead grows and, consequently, the faster the battery of mobile devices drains. By referring to several sparse RLNC...... techniques, and without any assumption on the implementation of the RLNC decoder in use, we provide an efficient way to characterize the performance of users targeted by ultra-reliable layered multicast services. The proposed modeling allows to efficiently derive the average number of coded packet...

Improving Reliability of Service Operation Using FMEA Review and New Opportunity for Investigations

Science.gov (United States)

Sutrisno, Agung; Gunawan, Indra

2016-01-01

Despite its growing contribution to the global economy, investigation on the application status of service FMEA study to support realization of reliable service operation is very limited in literature. Motivated by such situation, the paper presented an initial survey on the status and research gaps in developing and applying FMEA in service sectors. Systematic preliminary survey using specific criteria are undertaken. Our study indicated that development and application of service FMEA are partially addressing the characteristics of service operations and it is still applied into the good deed and profit oriented operations. Opportunities for further investigation pertaining to advancement of its decision supporting tool for service risk appraisal, its modification to cope with sustainability related requirements and application of service FMEA in not for profit oriented operations are presented as new avenues for further investigation

Service differentiation in spare parts supply through dedicated stocks

NARCIS (Netherlands)

Alvarez, Elisa; van der Heijden, Matthijs C.; Zijm, Willem H.M.

2012-01-01

We investigate keeping dedicated stocks at customer sites in addition to stock kept at some central location as a tool for applying service differentiation in spare parts supply. We study the resulting two-echelon system in a multi-item setting, both under backordering and under emergency shipments

Flexible, Secure, and Reliable Data Sharing Service Based on Collaboration in Multicloud Environment

Directory of Open Access Journals (Sweden)

Qiang Wei

2018-01-01

Full Text Available Due to the abundant storage resources and high reliability data service of cloud computing, more individuals and enterprises are motivated to outsource their data to public cloud platform and enable legal data users to search and download what they need in the outsourced dataset. However, in “Paid Data Sharing” model, some valuable data should be encrypted before outsourcing for protecting owner’s economic benefits, which is an obstacle for flexible application. Specifically, if the owner does not know who (user will download which data files in advance and even does not know the attributes of user, he/she has to either remain online all the time or import a trusted third party (TTP to distribute the file decryption key to data user. Obviously, making the owner always remain online is too inflexible, and wholly depending on the security of TTP is a potential risk. In this paper, we propose a flexible, secure, and reliable data sharing scheme based on collaboration in multicloud environment. For securely and instantly providing data sharing service even if the owner is offline and without TTP, we distribute all encrypted split data/key blocks together to multiple cloud service providers (CSPs, respectively. An elaborate cryptographic protocol we designed helps the owner verify the correctness of data exchange bills, which is directly related to the owner’s economic benefits. Besides, in order to support reliable data service, the erasure-correcting code technic is exploited for tolerating multiple failures among CSPs, and we offer a secure keyword search mechanism that makes the system more close to reality. Extensive security analyses and experiments on real-world data show that our scheme is secure and efficient.

Morphological analysis of energy services: Paving the way to quality differentiation in the power sector

International Nuclear Information System (INIS)

Salah, Florian; Flath, Christoph M.; Schuller, Alexander; Will, Christian; Weinhardt, Christof

2017-01-01

The activation of the still predominantly passive demand side is necessary to further guarantee a stable power system in the short term and ensure capacity adequacy in the long run. A system with a high share of generators with nearly no marginal costs requires new services that facilitate transmitting the right economic signals to the system stakeholders. To this end we refine the notion of energy services and propose a framework to systematically design quality differentiated energy services for consumers. This approach facilitates a value-based economic assessment of energy services that deviates from the marginal-cost-paradigm. We further illustrate pricing options for these new energy service products and outline infrastructural needs and additional use case-specific product properties. Moreover, we discuss how the morphological approach can be formalised using a mathematical programming formulation and introduce a complexity measure that facilitates assessing potential adoption obstacles for end consumers. Additionally, we illustrate the practical applicability of these findings by using a prototypical implementation of a decision support system. To foster differentiated energy services, we recommend a more lenient regulatory regime lowering the barriers for new market entrants. - Highlights: • Activating the demand side is necessary to further guarantee a stable power system. • We refine the notion of energy services helping to tackle this obstacle. • A morphological box to design quality differentiated energy services is proposed. • We extend this framework by implementing a prototypical decision support system. • A more lenient regulatory regime is needed to foster differentiated energy services.

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.

Assessing rural small community water supply in Limpopo, South Africa: water service benchmarks and reliability.

Science.gov (United States)

Majuru, Batsirai; Jagals, Paul; Hunter, Paul R

2012-10-01

Although a number of studies have reported on water supply improvements, few have simultaneously taken into account the reliability of the water services. The study aimed to assess whether upgrading water supply systems in small rural communities improved access, availability and potability of water by assessing the water services against selected benchmarks from the World Health Organisation and South African Department of Water Affairs, and to determine the impact of unreliability on the services. These benchmarks were applied in three rural communities in Limpopo, South Africa where rudimentary water supply services were being upgraded to basic services. Data were collected through structured interviews, observations and measurement, and multi-level linear regression models were used to assess the impact of water service upgrades on key outcome measures of distance to source, daily per capita water quantity and Escherichia coli count. When the basic system was operational, 72% of households met the minimum benchmarks for distance and water quantity, but only 8% met both enhanced benchmarks. During non-operational periods of the basic service, daily per capita water consumption decreased by 5.19l (pwater sources were 639 m further (p ≤ 0.001, 95% CI 560-718). Although both rudimentary and basic systems delivered water that met potability criteria at the sources, the quality of stored water sampled in the home was still unacceptable throughout the various service levels. These results show that basic water services can make substantial improvements to water access, availability, potability, but only if such services are reliable. Copyright © 2012 Elsevier B.V. All rights reserved.

Demonstration of Essential Reliability Services by a 300-MW Solar Photovoltaic Power Plant

Energy Technology Data Exchange (ETDEWEB)

Loutan, Clyde; Klauer, Peter; Chowdhury, Sirajul; Hall, Stephen; Morjaria, Mahesh; Chadliev, Vladimir; Milam, Nick; Milan, Christopher; Gevorgian, Vahan

2017-03-24

The California Independent System Operator (CAISO), First Solar, and the National Renewable Energy Laboratory (NREL) conducted a demonstration project on a large utility-scale photovoltaic (PV) power plant in California to test its ability to provide essential ancillary services to the electric grid. With increasing shares of solar- and wind-generated energy on the electric grid, traditional generation resources equipped with automatic governor control (AGC) and automatic voltage regulation controls -- specifically, fossil thermal -- are being displaced. The deployment of utility-scale, grid-friendly PV power plants that incorporate advanced capabilities to support grid stability and reliability is essential for the large-scale integration of PV generation into the electric power grid, among other technical requirements. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, PV power plants can be used to mitigate the impact of variability on the grid, a role typically reserved for conventional generators. In August 2016, testing was completed on First Solar's 300-MW PV power plant, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to use grid-friendly controls to provide essential reliability services. These data showed how the development of advanced power controls can enable PV to become a provider of a wide range of grid services, including spinning reserves, load following, voltage support, ramping, frequency response, variability smoothing, and frequency regulation to power quality. Specifically, the tests conducted included various forms of active power control such as AGC and frequency regulation; droop response; and reactive power, voltage, and power factor controls. This project demonstrated that advanced power electronics and solar generation can be

Towards Reliable Integrated Services for Dependable Systems

DEFF Research Database (Denmark)

Schiøler, Henrik; Ravn, Anders Peter; Izadi-Zamanabadi, Roozbeh

Reliability issues for various technical systems are discussed and focus is directed towards distributed systems, where communication facilities are vital to maintain system functionality. Reliability in communication subsystems is considered as a resource to be shared among a number of logical c...... applications residing on alternative routes. Details are provided for the operation of RRRSVP based on reliability slack calculus. Conclusions summarize the considerations and give directions for future research....... connections and a reliability management framework is suggested. We suggest a network layer level reliability management protocol RRSVP (Reliability Resource Reservation Protocol) as a counterpart of the RSVP for bandwidth and time resource management. Active and passive standby redundancy by background...

Towards Reliable Integrated Services for Dependable Systems

DEFF Research Database (Denmark)

Schiøler, Henrik; Ravn, Anders Peter; Izadi-Zamanabadi, Roozbeh

2003-01-01

Reliability issues for various technical systems are discussed and focus is directed towards distributed systems, where communication facilities are vital to maintain system functionality. Reliability in communication subsystems is considered as a resource to be shared among a number of logical c...... applications residing on alternative routes. Details are provided for the operation of RRRSVP based on reliability slack calculus. Conclusions summarize the considerations and give directions for future research....... connections and a reliability management framework is suggested. We suggest a network layer level reliability management protocol RRSVP (Reliability Resource Reservation Protocol) as a counterpart of the RSVP for bandwidth and time resource management. Active and passive standby redundancy by background...

A call for differentiated approaches to delivering HIV services to key populations.

Science.gov (United States)

Macdonald, Virginia; Verster, Annette; Baggaley, Rachel

2017-07-21

Key populations (KPs) are disproportionally affected by HIV and have low rates of access to HIV testing and treatment services compared to the broader population. WHO promotes the use of differentiated approaches for reaching and recruiting KP into the HIV services continuum. These approaches may help increase access to KPs who are often criminalized or stigmatized. By catering to the specific needs of each KP individual, differentiated approaches may increase service acceptability, quality and coverage, reduce costs and support KP members in leading the HIV response among their communities. WHO recommends the implementation of community-based and lay provider administered HIV testing services. Together, these approaches reduce barriers and costs associated with other testing strategies, allow greater ownership in HIV programmes for KP members and reach more people than do facility-based services. Despite this evidence availability and support for them is limited. Peer-driven interventions have been shown to be effective in engaging, recruiting and supporting clients. Some programmes employ HIV-positive or non-PLHIV "peer navigators" and other staff to provide case management, enrolment and/or re-enrolment in care and treatment services. However, a better understanding of the impact, cost effectiveness and potential burden on peer volunteers is required. Task shifting and non-facility-based service locations for antiretroviral therapy (ART) initiation and maintenance and antiretroviral (ARV) distribution are recommended in both the consolidated HIV treatment and KP guidelines of WHO. These approaches are accepted in generalized epidemics and for the general population where successful models exist; however, few organizations provide or initiate ART at KP community-based services. The application of a differentiated service approach for KP could increase the number of people who know their status and receive effective and sustained prevention and treatment for HIV

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...

In-service inspection as an aid to steel pressure vessel reliability

International Nuclear Information System (INIS)

Nichols, R.W.

1975-01-01

In-service inspection has played an important role in non-nuclear pressure vessel technology, being a legal requirement in many countries. Evidence from surveys of reliability of non-nuclear plant has suggested that such inspections can be effective in reducing the risk of subsequent failures. Recent requirements of the ASME XI code which will be summarised have important implications on the techniques to be used for in-service inspection, and so on design and fabrication aspects. Moreover, in-service inspection can only be an effective procedure if its possible weaknesses are recognised. The first problem is to ensure that an ultrasonic technique is used which is capable of detecting defects of an order of magnitude smaller than the critical size for each particular situation, in whatever defect orientation is important. The potential of different ultrasonic techniques will be compared. Next it is necessary to ensure coverage of all the relevant material. In this respect machine operation is superior to manual scanning, so that manipulation and scanning devices have to be developed. Problems of local geometry and of deviations in geometry have to be discussed with designer and fabricator; plate and clad quality have to be controlled (with respect to surface contour, metallurgical condition and freedom from interfering defects) to ensure inspectability in depth. The reliability of the mechanical and electronic equipment has to be assessed and designed to meet high requirements. Some presentational aids to detection and interpretation will be discussed. Having located a potential defect, the application of fracture mechanics treatments requires knowledge of size, shape and orientation. Some of the problems will be discussed together with possible solutions. (author)

Using Partial Differential Equations for Pricing of Goods and Services

Directory of Open Access Journals (Sweden)

Traykov Metodi

2016-06-01

Full Text Available This article is based on the methodology of comparative analysis, using an innovative approach for pricing of various goods and services. Benchmarking is the continuous search to find and adapt better pricing methods that leading to increased profits. We will consider the numerical solution of partial differential equations, based on Black-Scholes model for pricing of goods and services within European option. Also, we will present formulation and numerical behavior of explicit and implicit methods that can be use in pricing for company assets within European option.

Some reliability targets affecting the necessary provisions for in-service inspection and monitoring of LMFBR engineering components

International Nuclear Information System (INIS)

Bolt, P.R.

1980-01-01

The possible consequences of failure of primary and secondary sodium circuit components are discussed with particular reference to post incident fault diagnosis, remedial procedures and outage durations. The core support structures and steam generator units are identified as particularly important components in terms of economic consequence of their failure. Important safety considerations may also apply. Levels of reliability for core support and steam generator integrity, necessary to meet economic and certain safety criteria, are discussed and quantitative data is given. Possible failure and deterioration mechanisms which could result in unacceptable reductions in reliability are then identified for the core support and steam generator units. Following a consideration of the reliability targets and possible causes of loss of reliability, an appraisal is made of the necessary extent of in-service data to be obtained on component behaviour and condition. In-service inspection and monitoring methods that could be used to obtain this data are described. Consideration is given to UK and overseas inspection experience on LMFBR and other nuclear plant. (author)

Some reliability targets affecting the necessary provisions for in-service inspection and monitoring of LMFBR engineering components

Energy Technology Data Exchange (ETDEWEB)

Bolt, P R [Fast Reactor Engineering, Plant Engineering Department, CEGB, Barnwood, Gloucester (United Kingdom)

1980-11-01

The possible consequences of failure of primary and secondary sodium circuit components are discussed with particular reference to post incident fault diagnosis, remedial procedures and outage durations. The core support structures and steam generator units are identified as particularly important components in terms of economic consequence of their failure. Important safety considerations may also apply. Levels of reliability for core support and steam generator integrity, necessary to meet economic and certain safety criteria, are discussed and quantitative data is given. Possible failure and deterioration mechanisms which could result in unacceptable reductions in reliability are then identified for the core support and steam generator units. Following a consideration of the reliability targets and possible causes of loss of reliability, an appraisal is made of the necessary extent of in-service data to be obtained on component behaviour and condition. In-service inspection and monitoring methods that could be used to obtain this data are described. Consideration is given to UK and overseas inspection experience on LMFBR and other nuclear plant. (author)

Implementation of Service Differentiation to Achieve Competitive Advantage. Case: Nevsky Hotel Grand.

OpenAIRE

Martysevich, Anna

2013-01-01

The main purpose of the thesis was to find out which hotel services could bring competitive advantage to the Nevsky Hotel Grand and differentiate the hotel from the competitors. What could be improved in the services of the hotel or which kind of services could be created in the hotel in order to attract more customers and be competitive on the market. The theoretical framework of the thesis was based on the data gathered from various sources of information in printed and electronic form s...

Retail banking service quality: A client perception study

Directory of Open Access Journals (Sweden)

Mbablemhle Bhengu

2016-11-01

Full Text Available The retail banking sector in South Africa is predominantly characterised by a high face to face interaction and constant product and pricing differentiation. In order for a bank to distinguish itself from other banks in the banking industry, it uses excellence in its service quality to stand out against its competitors. In the study, the researchers adapted the SERVQUAL model to the banking industry. A probability sampling technique was employed for the study. Simple random sampling was employed to test MBA students’ perceptions towards service quality in the banking industry. The findings in the empirical study revealed that MBA students at the university were dissatisfied with the quality of service offerings provided by the retail banks in South Africa. There were quality gaps revealed in tangibles, reliability, empathy, responsiveness and reliability aspects of the service encounters

Supporting differentiated quality of service in optical burst switched networks

Science.gov (United States)

Zhou, Bin; Bassiouni, Mostafa A.

2006-01-01

We propose and evaluate two new schemes for providing differentiated services in optical burst switched (OBS) networks. The two new schemes are suitable for implementation in OBS networks using just-in-time (JIT) or just-enough-time (JET) scheduling protocols. The first scheme adjusts the size of the search space for a free wavelength based on the priority level of the burst. A simple equation is used to divide the search spectrum into two parts: a base part and an adjustable part. The size of the adjustable part increases as the priority of the burst becomes higher. The scheme is very easy to implement and does not demand any major software or hardware resources in optical cross-connects. The second scheme reduces the dropping probability of bursts with higher priorities through the use of different proactive discarding rates in the network access station (NAS) of the source node. Our extensive simulation tests using JIT show that both schemes are capable of providing tangible quality of service (QoS) differentiation without negatively impacting the throughput of OBS networks.

Distributor pricing approaches enabled in Smart Grid to differentiate delivery service quality

Directory of Open Access Journals (Sweden)

Zhongwei Jake Zhang

2014-12-01

Full Text Available Industry practitioners who advocate retail competition and Demand-side Participation now look for approaches to link both initiatives through distributor pricing. As distributors incrementally convert more traditional assets into Smart Grid assets, they also need to consider different pricing approaches to recover the investment costs and meet the regulatory business requirements. Small electricity consumers need incentives to take part in these initiatives but their delivery service quality should also be closely guarded. Hence this paper addresses the above needs as a whole and investigates a set of distributor pricing approaches with Smart Grid technologies. Pricing of network and non-network based solutions should follow the incremental basis, such as the long run average incremental cost (LRAIC. The benefit of deferring network investment is calculated and should be passed to consumers as peak pricing rebate. A concept of reliability premium (RP based on load point reliability index is proposed, through which customers can express their preference of service quality and adjust their network tariff payment accordingly. A service delivery model is also proposed to utilize the savings from wholesale market trading to compensate for the downgraded service when loads are controlled. The IEEE 123-node distribution test feeder and the IEEE distribution system for RBTS Bus No. 2 are simulated, and solved using General Algebraic Modeling System (GAMS to demonstrate the proposed distributor pricing approaches in Smart Grid.

Reliability and Validity of SERVQUAL Scores Used To Evaluate Perceptions of Library Service Quality.

Science.gov (United States)

Thompson, Bruce; Cook, Colleen

Research libraries are increasingly supplementing collection counts with perceptions of service quality as indices of status and productivity. The present study was undertaken to explore the reliability and validity of scores from the SERVQUAL measurement protocol (A. Parasuraman and others, 1991), which has previously been used in this type of…

Beyond redundancy how geographic redundancy can improve service availability and reliability of computer-based systems

CERN Document Server

Bauer, Eric; Eustace, Dan

2012-01-01

"While geographic redundancy can obviously be a huge benefit for disaster recovery, it is far less obvious what benefit is feasible and likely for more typical non-catastrophic hardware, software, and human failures. Georedundancy and Service Availability provides both a theoretical and practical treatment of the feasible and likely benefits of geographic redundancy for both service availability and service reliability. The text provides network/system planners, IS/IT operations folks, system architects, system engineers, developers, testers, and other industry practitioners with a general discussion about the capital expense/operating expense tradeoff that frames system redundancy and georedundancy"--

Implementing eco friendly highly reliable upload feature using multi 3G service

Science.gov (United States)

Tanutama, Lukas; Wijaya, Rico

2017-12-01

The current trend of eco friendly Internet access is preferred. In this research the understanding of eco friendly is minimum power consumption. The devices that are selected have operationally low power consumption and normally have no power consumption as they are hibernating during idle state. To have the reliability a router of a router that has internal load balancing feature will provide the improvement of previous research on multi 3G services for broadband lines. Previous studies emphasized on accessing and downloading information files from Public Cloud residing Web Servers. The demand is not only for speed but high reliability of access as well. High reliability will mean mitigating both direct and indirect high cost due to repeated attempts of uploading and downloading the large files. Nomadic and mobile computer users need viable solution. Following solution for downloading information has been proposed and tested. The solution is promising. The result is now extended to providing reliable access line by means of redundancy and automatic reconfiguration for uploading and downloading large information files to a Web Server in the Cloud. The technique is taking advantage of internal load balancing feature to provision a redundant line acting as a backup line. A router that has the ability to provide load balancing to several WAN lines is chosen. The WAN lines are constructed using multiple 3G lines. The router supports the accessing Internet with more than one 3G access line which increases the reliability and availability of the Internet access as the second line immediately takes over if the first line is disturbed.

A Fast and Reliable Broadcast Service for LTE-Advanced Exploiting Multihop Device-to-Device Transmissions

Directory of Open Access Journals (Sweden)

Giovanni Nardini

2017-11-01

Full Text Available Several applications, from the Internet of Things for smart cities to those for vehicular networks, need fast and reliable proximity-based broadcast communications, i.e., the ability to reach all peers in a geographical neighborhood around the originator of a message, as well as ubiquitous connectivity. In this paper, we point out the inherent limitations of the LTE (Long-Term Evolution cellular network, which make it difficult, if possible at all, to engineer such a service using traditional infrastructure-based communications. We argue, instead, that network-controlled device-to-device (D2D communications, relayed in a multihop fashion, can efficiently support this service. To substantiate the above claim, we design a proximity-based broadcast service which exploits multihop D2D. We discuss the relevant issues both at the UE (User Equipment, which has to run applications, and within the network (i.e., at the eNodeBs, where suitable resource allocation schemes have to be enforced. We evaluate the performance of a multihop D2D broadcasting using system-level simulations, and demonstrate that it is fast, reliable and economical from a resource consumption standpoint.

Service differentiated and adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems.

Science.gov (United States)

Xia, Feng; Li, Jie; Hao, Ruonan; Kong, Xiangjie; Gao, Ruixia

2013-01-01

Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.

Reliability constrained decision model for energy service provider incorporating demand response programs

International Nuclear Information System (INIS)

Mahboubi-Moghaddam, Esmaeil; Nayeripour, Majid; Aghaei, Jamshid

2016-01-01

Highlights: • The operation of Energy Service Providers (ESPs) in electricity markets is modeled. • Demand response as the cost-effective solution is used for energy service provider. • The market price uncertainty is modeled using the robust optimization technique. • The reliability of the distribution network is embedded into the framework. • The simulation results demonstrate the benefits of robust framework for ESPs. - Abstract: Demand response (DR) programs are becoming a critical concept for the efficiency of current electric power industries. Therefore, its various capabilities and barriers have to be investigated. In this paper, an effective decision model is presented for the strategic behavior of energy service providers (ESPs) to demonstrate how to participate in the day-ahead electricity market and how to allocate demand in the smart distribution network. Since market price affects DR and vice versa, a new two-step sequential framework is proposed, in which unit commitment problem (UC) is solved to forecast the expected locational marginal prices (LMPs), and successively DR program is applied to optimize the total cost of providing energy for the distribution network customers. This total cost includes the cost of purchased power from the market and distributed generation (DG) units, incentive cost paid to the customers, and compensation cost of power interruptions. To obtain compensation cost, the reliability evaluation of the distribution network is embedded into the framework using some innovative constraints. Furthermore, to consider the unexpected behaviors of the other market participants, the LMP prices are modeled as the uncertainty parameters using the robust optimization technique, which is more practical compared to the conventional stochastic approach. The simulation results demonstrate the significant benefits of the presented framework for the strategic performance of ESPs.

A Service Differentiated MAC Protocol for OFDM/TDMA Wireless Systems

Institute of Scientific and Technical Information of China (English)

WANG Ying; ZHANG Ping

2005-01-01

This paper proposes a Service Differentiated-Dynamic Slotted Multiple Access (SD-DSMA) protocol with QoS guarantee. The Media Access Control (MAC) frame format is variable according to the traffic of uplink and downlink and the traffic of control and data. In addition, the services are divided into two categories, Guaranteed Bandwidth (GB) and Best Effort (BE). Uplink control message slots are designed for the GB users to reduce contention. Taking into consideration the techniques in physical layer, a two-Dimensional Radio Resource Allocation (2-D RRA) method is proposed. The 2-D RRA is an efficient way to allocate radio resources for multi-cell, multi-user OFDM/TDMA system as it takes into consideration both the channel condition and the co-channel interference. The piggyback mechanism and fair scheduling algorithm are adopted for GB services, and the max C/I scheduling algorithm is used for BE services. The simulation results show that the proposed MAC protocol has better performance in terms of delay, probability of successful access request.

Does Head Start differentially benefit children with risks targeted by the program's service model?

Science.gov (United States)

Miller, Elizabeth B; Farkas, George; Duncan, Greg J

Data from the Head Start Impact Study ( N = 3540) were used to test for differential benefits of Head Start after one program year and after kindergarten on pre-academic and behavior outcomes for children at risk in the domains targeted by the program's comprehensive services. Although random assignment to Head Start produced positive treatment main effects on children's pre-academic skills and behavior problems, residualized growth models showed that random assignment to Head Start did not differentially benefit the pre-academic skills of children with risk factors targeted by the Head Start service model. The models showed detrimental impacts of Head Start for maternal-reported behavior problems of high-risk children, but slightly more positive impacts for teacher-reported behavior. Policy implications for Head Start are discussed.

Beliefs concerning the reliability of nuclear power plant in-service inspections; Uskomuksia ydinvoimalaitoksissa suoritettavien tarkastusten luotettavuudesta

Energy Technology Data Exchange (ETDEWEB)

Kettunen, J. [VTT Automation, Espoo (Finland)

1997-01-01

The aim of the study was to investigate belief systems held by the officials responsible for the planning and supervision of NDT operations within the Finnish nuclear industry. They were asked to express their opinions on (1) the reliability of NDT methods in general, (2) the factors influencing the reliability of in-service inspections, and (3) the degree of reliability of the current inspections operations conducted by means of NDT methods in the Finnish nuclear power plants. Another goal of the study was to assess the adequacy of officials` beliefs (or belief systems). The research data was collected by interviewing representatives from Finnish power companies (Imatran Voima Oy and Teollisuuden Voima Oy), independent inspection organisations, and the Finnish Centre for Radiation and Nuclear Safety (STUK). The adequacy of the beliefs expressed was assessed by means of the results obtained from international NDT reliability studies and on the basis of interviewees` own justification. (refs.).

A Scalable and Reliable Message Transport Service for the ATLAS Trigger and Data Acquisition System

CERN Document Server

Kazarov, A; The ATLAS collaboration; Kolos, S; Lehmann Miotto, G; Soloviev, I

2014-01-01

The ATLAS Trigger and Data Acquisition (TDAQ) is a large distributed computing system composed of several thousands of interconnected computers and tens of thousands applications. During a run, TDAQ applications produce a lot of control and information messages with variable rates, addressed to TDAQ operators or to other applications. Reliable, fast and accurate delivery of the messages is important for the functioning of the whole TDAQ system. The Message Transport Service (MTS) provides facilities for the reliable transport, the filtering and the routing of the messages, basing on publish-subscribe-notify communication pattern with content-based message filtering. During the ongoing LHC shutdown, the MTS was re-implemented, taking into account important requirements like reliability, scalability and performance, handling of slow subscribers case and also simplicity of the design and the implementation. MTS uses CORBA middleware, a common layer for TDAQ infrastructure, and provides sending/subscribing APIs i...

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

Science.gov (United States)

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

2013-01-01

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

A reliable protocol for the isolation of viable, chondrogenically differentiated human mesenchymal stem cells from high-density pellet cultures.

Science.gov (United States)

Ullah, Mujib; Hamouda, Houda; Stich, Stefan; Sittinger, Michael; Ringe, Jochen

2012-12-01

Administration of chondrogenically differentiated mesenchymal stem cells (MSC) is discussed as a promising approach for the regenerative treatment of injured or diseased cartilage. The high-density pellet culture is the standard culture for chondrogenic differentiation, but cells in pellets secrete extracellular matrix (ECM) that they become entrapped in. Protocols for cell isolation from pellets often result in cell damage and dedifferentiation towards less differentiated MSC. Therefore, our aim was to develop a reliable protocol for the isolation of viable, chondrogenically differentiated MSC from high-density pellet cultures. Human bone marrow MSC were chondrogenically stimulated with transforming growth factor-β3, and the cartilaginous structure of the pellets was verified by alcian blue staining of cartilage proteoglycans, antibody staining of cartilage collagen type II, and quantitative real-time reverse-transcription polymerase chain reaction of the marker genes COL2A1 and SOX9. Trypsin and collagenases II and P were tested alone or in combination, and for different concentrations and times, to find a protocol for optimized pellet digestion. Whereas trypsin was not able to release viable cells, 90-min digestion with 300 U of collagenase II, 20 U of collagenase P, and 2 mM CaCl2 worked quite well and resulted in about 2.5×10(5) cells/pellet. The protocol was further optimized for the separation of released cells and ECM from each other. Cells were alcian blue and collagen type II positive and expressed COL2A1 and SOX9, verifying a chondrogenic character. However, they had different morphological shapes. The ECM was also uniformly alcian blue and collagen type II positive but showed different organizational and structural forms. To conclude, our protocol allows the reliable isolation of a defined number of viable, chondrogenically differentiated MSC from high-density pellet cultures. Such cells, as well as the ECM components, are of interest as

Differential Game Analyses of Logistics Service Supply Chain Coordination by Cost Sharing Contract

Directory of Open Access Journals (Sweden)

Haifeng Zhao

2014-01-01

Full Text Available Cooperation of all the members in a supply chain plays an important role in logistics service. The service integrator can encourage cooperation from service suppliers by sharing their cost during the service, which we assume can increase the sales by accumulating the reputation of the supply chain. A differential game model is established with the logistics service supply chain that consists of one service integrator and one supplier. And we derive the optimal solutions of the Nash equilibrium without cost sharing contract and the Stackelberg equilibrium with the integrator as the leader who partially shares the cost of the efforts of the supplier. The results make the benefits of the cost sharing contract in increasing the profits of both players as well as the whole supply chain explicit, which means that the cost sharing contract is an effective coordination mechanism in the long-term relationship of the members in a logistics service supply chain.

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.

Problematics of Reliability of Road Rollers

Science.gov (United States)

Stawowiak, Michał; Kuczaj, Mariusz

2018-06-01

This article refers to the reliability of road rollers used in a selected roadworks company. Information on the method of road rollers service and how the service affects the reliability of these rollers is presented. Attention was paid to the process of the implemented maintenance plan with regard to the machine's operational time. The reliability of road rollers was analyzed by determining and interpreting readiness coefficients.

Understanding the differentiating impacts of the communication strategies of a high involvement service (investment advisory services) and a high involvement product (precious jewellery) on customer satisfaction and loyalty.

OpenAIRE

Gupta, Gauri

2009-01-01

While marketing literature has largely focused on high and low involvement purchases and the positive relationship between customer satisfaction and loyalty; the differentiating impacts of communication strategies for a high involvement service and a high involvement product on customer satisfaction and loyalty has received little academic attention. Consequently, this study examines the differentiating impacts of the communication strategies for investment advisory services and precious jewe...

Differential Service in a Bidirectional Radio-over-Fiber System over a Spectral-Amplitude-Coding OCDMA Network

Directory of Open Access Journals (Sweden)

Chao-Chin Yang

2016-10-01

Full Text Available A new scheme of radio-over-fiber (RoF network based on spectral-amplitude-coding (SAC optical code division multiple access (OCDMA is herein proposed. Differential service is provided by a power control scheme that classifies users into several classes and assigns each of them with a specific power level. Additionally, the wavelength reuse technique is adapted to support bidirectional transmission and reduce base station (BS cost. Both simulation and numerical results show that significantly differential quality-of-service (QoS in bit-error rate (BER is achieved in both downlink and uplink transmissions.

Reliability and Availability of Cloud Computing

CERN Document Server

Bauer, Eric

2012-01-01

A holistic approach to service reliability and availability of cloud computing Reliability and Availability of Cloud Computing provides IS/IT system and solution architects, developers, and engineers with the knowledge needed to assess the impact of virtualization and cloud computing on service reliability and availability. It reveals how to select the most appropriate design for reliability diligence to assure that user expectations are met. Organized in three parts (basics, risk analysis, and recommendations), this resource is accessible to readers of diverse backgrounds and experience le

Serviceability design load factors and reliability assessments for reinforced concrete containment structures

International Nuclear Information System (INIS)

Han Bong Koo

1998-01-01

A reinforced concrete nuclear power plant containment structure is subjected to various random static and stochastic loads during its lifetime. Since these loads involve inherent randomness and other uncertainties, an appropriate probabilistic model for each load must be established in order to perform reliability analysis. The current ASME code for reinforced concrete containment structures are not based on probability concepts. The stochastic nature of natural hazard or accidental loads and the variations of material properties require a probabilistic approach for a rational assessment of structural safety and performance. The paper develops probability-based load factors for the limit state design of reinforced concrete containment structures. The purpose of constructing reinforced concrete containment structure is to protect against radioactive release, and so the use of a serviceability limit state against crack failure that can cause the emission of radioactive materials is suggested as a critical limit state for reinforced concrete containment structures. Load factors for the design of reinforced concrete containment structures are proposed and carried out the reliability assessments. (orig.)

Reliability and validity of the workplace harassment questionnaire for Korean finance and service workers.

Science.gov (United States)

Lee, Myeongjun; Kim, Hyunjung; Shin, Donghee; Lee, Sangyun

2016-01-01

Harassment means systemic and repeated unethical acts. Research on workplace harassment have been conducted widely and the NAQ-R has been widely used for the researches. But this tool, however the limitations in revealing differended in sub-factors depending on the culture and in reflecting that unique characteristics of the Koren society. So, The workplace harassment questionnaire for Korean finace and service workers has been developed to assess the level of personal harassment at work. This study aims to develop a tool to assess the level of personal harassment at work and to test its validity and reliability while examining specific characteristics of workplace harassment against finance and service workers in Korea. The framework of survey was established based on literature review, focused-group interview for the Korean finance and service workers. To verify its reliability, Cronbach's alpha coefficient was calculated; and to verify its validity, items and factors of the tool were analyzed. The correlation matrix analysis was examined to verify the tool's convergent validity and discriminant validity. Structural validity was verified by checking statistical significance in relation to the BDI-K. Cronbach's alpha coefficient of this survey was 0.93, which indicates a quite high level of reliability. To verify the appropriateness of this survey tool, its construct validity was examined through factor analysis. As a result of the factor analysis, 3 factors were extracted, explaining 56.5 % of the total variance. The loading values and communalities of the 20 items were 0.85 to 0.48 and 0.71 to 0.46. The convergent validity and discriminant validity were analyzed and rate of item discriminant validity was 100 %. Finally, for the concurrent validity, We examined the relationship between the WHI-KFSW and pschosocial stress by examining the correlation with the BDI-K. The results of chi-square test and multiple logistic analysis indicated that the correlation with

76 FR 66328 - Callaway Golf Ball Operations, Inc., Including On-Site Leased Workers From Reliable Temp Services...

Science.gov (United States)

2011-10-26

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-80,110] Callaway Golf Ball... Golf Ball Operations, Inc., including on-site leased workers from Reliable Temp Services, Inc., and... production of golf balls. The notice was published in the Federal Register on July 8, 2011 (76 FR 40401). At...

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....

The Validity and Reliability Studies of the Internet Use of Pre-Service English Teachers Survey: A Turkish Context

Directory of Open Access Journals (Sweden)

Gülşah Külekçi

2011-11-01

Full Text Available As the availability of computers and the Internet in schools and classrooms has grown, so has interest in the extent to which these technologies are being used and for what purposes. Recently there has been many studies on teachers’ use of education technology in their classrooms and schools, the availability of this technology in their classrooms and schools, their training and preparation for their use and the barriers to technology use they encounter. Using the Internet effectively and the success of the Internet utilization is very much related to the users’ attitudes toward the Internet. This study aims at investigating the reliability and the validity of the Internet Use of Pre-service English Teachers Survey modified from the Master Thesis of Sudsuang Yutdhana. The survey contains two subscales as Internet Attitude Scale and Self-perception of Computing Skills. The survey was administered to randomly selected third and fourth year 96 pre – service English Teachers at Dokuz Eylül University Buca, Faculty of Education, Department of English Language Teaching. The results indicated that Internet Use of Pre-service English Teachers Survey (IUPETS is reliable and valid.

Why We Need Reliable, Valid, and Appropriate Learning Disability Assessments: The Perspective of a Postsecondary Disability Service Provider

Science.gov (United States)

Wolforth, Joan

2012-01-01

This paper discusses issues regarding the validity and reliability of psychoeducational assessments provided to Disability Services Offices at Canadian Universities. Several vignettes illustrate some current issues and the potential consequences when university students are given less than thorough disability evaluations and ascribed diagnoses.…

Intraobserver and interobserver reliability of recategorized Neer classification in differentiating 2-part surgical neck fractures from multi-fragmented proximal humeral fractures in 116 patients

DEFF Research Database (Denmark)

Sumrein, Bakir O; Mattila, Ville M; Lepola, Vesa

2018-01-01

BACKGROUND: Optimal fracture classification should be simple and reproducible and should guide treatment. For proximal humeral fractures, the Neer classification is commonly used. However, intraobserver and interobserver reliability of the Neer classification has been shown to be poor. In clinical...... for interobserver reliability showed substantial correlation (0.61-0.73) and was as follows: 0.73 for radiographs alone, 0.61 for CT scans alone, and 0.72 for radiographs and CT scans viewed together. After 24 weeks, the process was repeated and intraobserver reliability was calculated.The κ coefficient...... for intraobserver reliability showed substantial correlation (0.62-0.75) and was as follows: 0.62 for radiographs alone, 0.64 for CT scans alone, and 0.75 for radiographs and CT scans viewed together. CONCLUSION: Clinicians were able to differentiate 2-part surgical neck fractures from multi-fragmented fractures...

Reliability and Validity of Survey Instruments to Measure Work-Related Fatigue in the Emergency Medical Services Setting: A Systematic Review

Science.gov (United States)

2018-01-11

Background: This study sought to systematically search the literature to identify reliable and valid survey instruments for fatigue measurement in the Emergency Medical Services (EMS) occupational setting. Methods: A systematic review study design wa...

Methodology for reliability based condition assessment

International Nuclear Information System (INIS)

Mori, Y.; Ellingwood, B.

1993-08-01

Structures in nuclear power plants may be exposed to aggressive environmental effects that cause their strength to decrease over an extended period of service. A major concern in evaluating the continued service for such structures is to ensure that in their current condition they are able to withstand future extreme load events during the intended service life with a level of reliability sufficient for public safety. This report describes a methodology to facilitate quantitative assessments of current and future structural reliability and performance of structures in nuclear power plants. This methodology takes into account the nature of past and future loads, and randomness in strength and in degradation resulting from environmental factors. An adaptive Monte Carlo simulation procedure is used to evaluate time-dependent system reliability. The time-dependent reliability is sensitive to the time-varying load characteristics and to the choice of initial strength and strength degradation models but not to correlation in component strengths within a system. Inspection/maintenance strategies are identified that minimize the expected future costs of keeping the failure probability of a structure at or below an established target failure probability during its anticipated service period

Test-retest Reliability and Agreement of the Satisfaction with the Assistive Technology Services (SATS) Instrument in Two Nordic Countries

DEFF Research Database (Denmark)

Sund, Terje; Anttila, Heidi; Iwarsson, Susanne

2014-01-01

Purpose: The purpose of this study was to investigate test–retest reliability, agreement, internal consistency, and floor- and ceiling effects of the Danish and Finnish versions of the Satisfaction with the Assistive Technology Services (SATS) instrument among adult users of powered wheelchairs (...

Does Head Start differentially benefit children with risks targeted by the program’s service model?☆

Science.gov (United States)

Miller, Elizabeth B.; Farkas, George; Duncan, Greg J.

2015-01-01

Data from the Head Start Impact Study (N = 3540) were used to test for differential benefits of Head Start after one program year and after kindergarten on pre-academic and behavior outcomes for children at risk in the domains targeted by the program’s comprehensive services. Although random assignment to Head Start produced positive treatment main effects on children’s pre-academic skills and behavior problems, residualized growth models showed that random assignment to Head Start did not differentially benefit the pre-academic skills of children with risk factors targeted by the Head Start service model. The models showed detrimental impacts of Head Start for maternal-reported behavior problems of high-risk children, but slightly more positive impacts for teacher-reported behavior. Policy implications for Head Start are discussed. PMID:26379369

Measuring Passenger Travel Time Reliability using Smartcard Data

NARCIS (Netherlands)

Bagherian, M.; Cats, O.; van Oort, N.; Hickman, M

2016-01-01

Service reliability is a key performance measure for transit agencies in increasing their service quality and thus ridership. Conventional reliability metrics are established based on vehicle movements and thus do not adequately reflect passenger’s experience. In the past few years, the growing

Reliable multi-label learning via conformal predictor and random forest for syndrome differentiation of chronic fatigue in traditional Chinese medicine.

Directory of Open Access Journals (Sweden)

Huazhen Wang

Full Text Available OBJECTIVE: Chronic Fatigue (CF still remains unclear about its etiology, pathophysiology, nomenclature and diagnostic criteria in the medical community. Traditional Chinese medicine (TCM adopts a unique diagnostic method, namely 'bian zheng lun zhi' or syndrome differentiation, to diagnose the CF with a set of syndrome factors, which can be regarded as the Multi-Label Learning (MLL problem in the machine learning literature. To obtain an effective and reliable diagnostic tool, we use Conformal Predictor (CP, Random Forest (RF and Problem Transformation method (PT for the syndrome differentiation of CF. METHODS AND MATERIALS: In this work, using PT method, CP-RF is extended to handle MLL problem. CP-RF applies RF to measure the confidence level (p-value of each label being the true label, and then selects multiple labels whose p-values are larger than the pre-defined significance level as the region prediction. In this paper, we compare the proposed CP-RF with typical CP-NBC(Naïve Bayes Classifier, CP-KNN(K-Nearest Neighbors and ML-KNN on CF dataset, which consists of 736 cases. Specifically, 95 symptoms are used to identify CF, and four syndrome factors are employed in the syndrome differentiation, including 'spleen deficiency', 'heart deficiency', 'liver stagnation' and 'qi deficiency'. THE RESULTS: CP-RF demonstrates an outstanding performance beyond CP-NBC, CP-KNN and ML-KNN under the general metrics of subset accuracy, hamming loss, one-error, coverage, ranking loss and average precision. Furthermore, the performance of CP-RF remains steady at the large scale of confidence levels from 80% to 100%, which indicates its robustness to the threshold determination. In addition, the confidence evaluation provided by CP is valid and well-calibrated. CONCLUSION: CP-RF not only offers outstanding performance but also provides valid confidence evaluation for the CF syndrome differentiation. It would be well applicable to TCM practitioners and

Risk-based Optimization and Reliability Levels of Coastal Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Burcharth, H. F.

Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure, in...... on the minimumcost reliability levels is investigated for different values of the real rate of interest, the service lifetime, the downtime costs due to malfunction and the decommission costs.......Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure...

Risk-based Optimization and Reliability Levels of Coastal Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Burcharth, Hans F.

2005-01-01

 Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure, i...... on the minimumcost reliability levels is investigated for different values of the real rate of interest, the service lifetime, the downtime costs due to malfunction and the decommission costs....... Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure...

Reliability of cone beam computed tomography as a biopsy-independent tool in differential diagnosis of periapical cysts and granulomas: An In vivo Study.

Science.gov (United States)

Chanani, Ankit; Adhikari, Haridas Das

2017-01-01

Differential diagnosis of periapical cysts and granulomas is required as their treatment modalities are different. The aim of this study was to evaluate the efficacy of cone beam computed tomography (CBCT) in the differential diagnosis of periapical cysts from granulomas. A single-centered observational study was carried out in the Department of Conservative Dentistry and Endodontics, Dr. R. Ahmed Dental College and Hospital, using CBCT and dental operating microscope. Forty-five lesions were analyzed using CBCT scans. One evaluator analyzed each CBCT scan for the presence of the following six characteristic radiological features: cyst like-location, shape, periphery, internal structure, effect on the surrounding structures, and cortical plate perforation. Another independent evaluator analyzed the CBCT scans. This process was repeated after 6 months, and inter- and intrarater reliability of CBCT diagnoses was evaluated. Periapical surgeries were performed and tissue samples were obtained for histopathological analysis. To evaluate the efficacy, CBCT diagnoses were compared with histopathological diagnoses, and six receiver operating characteristic (ROC) curve analyses were conducted. ROC curve, Cronbach's alpha (α) test, and Cohen Kappa (κ) test were used for statistical analysis. Both inter- and intrarater reliability were excellent (α = 0.94, κ = 0.75 and 0.77, respectively). ROC curve with regard to ≥4 positive findings revealed the highest area under curve (0.66). CBCT is moderately accurate in the differential diagnosis of periapical cysts and granulomas.

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....

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

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...

Measuring Passenger Travel Time Reliability Using Smart Card Data

NARCIS (Netherlands)

Bagherian, M.; Cats, O.; van Oort, N.; Hickman, M

2016-01-01

Service reliability is a key performance measure for transit agencies in increasing their service quality and thus ridership. Conventional reliability metrics are established based on vehicle movements and thus do not adequately reflect passenger’s experience. In the past few years, the growing

Updated Value of Service Reliability Estimates for Electric Utility Customers in the United States

Energy Technology Data Exchange (ETDEWEB)

Sullivan, Michael [Nexant Inc., Burlington, MA (United States); Schellenberg, Josh [Nexant Inc., Burlington, MA (United States); Blundell, Marshall [Nexant Inc., Burlington, MA (United States)

2015-01-01

This report updates the 2009 meta-analysis that provides estimates of the value of service reliability for electricity customers in the United States (U.S.). The meta-dataset now includes 34 different datasets from surveys fielded by 10 different utility companies between 1989 and 2012. Because these studies used nearly identical interruption cost estimation or willingness-to-pay/accept methods, it was possible to integrate their results into a single meta-dataset describing the value of electric service reliability observed in all of them. Once the datasets from the various studies were combined, a two-part regression model was used to estimate customer damage functions that can be generally applied to calculate customer interruption costs per event by season, time of day, day of week, and geographical regions within the U.S. for industrial, commercial, and residential customers. This report focuses on the backwards stepwise selection process that was used to develop the final revised model for all customer classes. Across customer classes, the revised customer interruption cost model has improved significantly because it incorporates more data and does not include the many extraneous variables that were in the original specification from the 2009 meta-analysis. The backwards stepwise selection process led to a more parsimonious model that only included key variables, while still achieving comparable out-of-sample predictive performance. In turn, users of interruption cost estimation tools such as the Interruption Cost Estimate (ICE) Calculator will have less customer characteristics information to provide and the associated inputs page will be far less cumbersome. The upcoming new version of the ICE Calculator is anticipated to be released in 2015.

Restructuring local distribution services: Possibilities and limitations

Energy Technology Data Exchange (ETDEWEB)

Duann, D.J.

1994-08-01

The restructuring of local distribution services is now the focus of the natural gas industry. It is the last major step in the ``reconstitution`` of the natural gas industry and a critical clement in realizing the full benefits of regulatory and market reforms that already have taken place in the wellhead and interstate markets. It could also be the most important regulatory initiative for most end-use customers because they are affected directly by the costs and reliability of distribution services. Several factors contribute to the current emphasis on distribution service restructuring. They include the unbundling and restructuring of upstream markets, a realization of the limitations of supply-side options (such as gas procurement oversight), and the increased diversity and volatility of gas demand facing local distribution companies. Local distribution service is not one but a series of activities that start with commodity gas procurement and extend to transportation, load balancing, storage, and metering and billing of services provided. There are also considerable differences in the economies of scale and scope associated with these various activities. Thus, a mixture of supply arrangements (such as a competitive market or a monopoly) is required for the most efficient delivery of local distribution services. A distinction must be made between the supply of commodity gas and the provision of a bundled distribution service. This distinction and identification of the best supply arrangements for various distribution service components are the most critical factors in developing appropriate restructuring policies. For most state public utility commissions the criteria for service restructuring should include pursuing the economies of scale and scope in gas distribution, differentiating and matching gas service reliability and quality with customer requirements, and controlling costs associated with the search, negotiation, and contracting of gas services.

Human reliability impact on in-service inspection

International Nuclear Information System (INIS)

Spanner, J.C. Sr.

1986-01-01

This paper describes a study conducted to identify, characterize, and evaluate the human reliability aspects of ultrasonic testing/inservice inspection (UT/ISI). Recent measurements of UT/ISI system effectiveness have revealed wide variations in performance; suggesting that insufficient emphasis is being placed on the human reliability aspects of nondestructive examination. It appears that NDE performance can be improved through application of the human factors principles relating to the task, training, procedure, environmental, and individual difference variables. These variables are collectively referred to as performance-shaping factors. A man-machine systems model was developed to describe the UT/ISI process using functional task descriptors. The relative operating characteristic (ROC) analysis method, which is derived from signal detection theory, offers unique attributes for analyzing NDT performance. The results of a limited human factors evaluation conducted in conjunction with a mini-round robin test are also described

The influence of frequency and reliability of in-service inspection on reactor pressure vessel disruptive failure probability

International Nuclear Information System (INIS)

Jordan, G.M.

1978-01-01

A simple probabilistic methodology is used to investigate the benefit, in terms of reduction of disruptive failure probability, which comes from the application of periodic in-service inspection to nuclear pressure vessels. The analysis indicates the strong interaction between inspection benefit and the intrinsic quality of the structure. In order to quantify the inspection benefit, assumptions are made which allow the quality to be characterised in terms of the parameters governing a log normal distribution of time - to - failure. Using these assumptions, it is shown that the overall benefit of in-service inspection unlikely to exceed an order of magnitude in terms of reduction of disruptive failure probability. The method is extended to evaluate the effect of the periodicity and reliability of the inspection process itself. (author)

A method to assign failure rates for piping reliability assessments

International Nuclear Information System (INIS)

Gamble, R.M.; Tagart, S.W. Jr.

1991-01-01

This paper reports on a simplified method that has been developed to assign failure rates that can be used in reliability and risk studies of piping. The method can be applied on a line-by-line basis by identifying line and location specific attributes that can lead to piping unreliability from in-service degradation mechanisms and random events. A survey of service experience for nuclear piping reliability also was performed. The data from this survey provides a basis for identifying in-service failure attributes and assigning failure rates for risk and reliability studies

Teaming up to improve reliability

International Nuclear Information System (INIS)

Malone, E.A.; Ayres, D.J.; Lear, R.C. van

1989-01-01

Responding to increasingly stringent regulatory requirements, Babcock and Wilcox has teamed up with three specialist companies to provide services for nuclear utilities aiming to improve the performance of their valves and actuators. The services, which are outlined here, include inspection, repair, overhaul and valve and actuator reliability programmes. (author)

An enhanced reliability-oriented workforce planning model for process industry using combined fuzzy goal programming and differential evolution approach

Science.gov (United States)

Ighravwe, D. E.; Oke, S. A.; Adebiyi, K. A.

2018-03-01

This paper draws on the "human reliability" concept as a structure for gaining insight into the maintenance workforce assessment in a process industry. Human reliability hinges on developing the reliability of humans to a threshold that guides the maintenance workforce to execute accurate decisions within the limits of resources and time allocations. This concept offers a worthwhile point of deviation to encompass three elegant adjustments to literature model in terms of maintenance time, workforce performance and return-on-workforce investments. These fully explain the results of our influence. The presented structure breaks new grounds in maintenance workforce theory and practice from a number of perspectives. First, we have successfully implemented fuzzy goal programming (FGP) and differential evolution (DE) techniques for the solution of optimisation problem in maintenance of a process plant for the first time. The results obtained in this work showed better quality of solution from the DE algorithm compared with those of genetic algorithm and particle swarm optimisation algorithm, thus expressing superiority of the proposed procedure over them. Second, the analytical discourse, which was framed on stochastic theory, focusing on specific application to a process plant in Nigeria is a novelty. The work provides more insights into maintenance workforce planning during overhaul rework and overtime maintenance activities in manufacturing systems and demonstrated capacity in generating substantially helpful information for practice.

Relative thinking in consumer choice between differentiated goods and services and its implications for business strategy

Directory of Open Access Journals (Sweden)

Ofer H. Azar

2011-02-01

Full Text Available The article shows that when people consider differentiated goods or services that differ in price and quality, they exhibit a decision-making bias of ``relative thinking'': relative price differences affect them even when economic theory suggests that only absolute price differences matter. This result is obtained in four different consumption categories. Sometimes subjects are affected only by relative price differences (``full relative thinking'' and sometimes also by absolute price differences (``partial relative thinking''. This behavior has implications for various disciplines, and it is particularly relevant in models dealing with horizontal or vertical differentiation, optimal pricing, competitive strategy, or advertising.

Quality of service in the Netherlands

Energy Technology Data Exchange (ETDEWEB)

Knijp, J.; Zwart, T. de; Frenken, R.M.L. [KEMA (Netherlands)

1997-12-31

Growing competition between utilities, changing legislation and increased usage of sensitive and disturbing end-user equipment, are some reasons for growing attention for the customers` view towards the product electricity and its related services. This growing interest certainly does not mean that the technical quality level always has to be increased. This depends mainly on the requirements and expectations of the customers. Achieving a reliable power supply at high quality level requires enormous investments. For electric utilities, it is important to know how the customers value the delivered products and services in order to determine if the investments are proportionally. Utilities need new tools and techniques to search for an optimal quality level for each customer. Product differentiation and additional services can be developed if the right information is available. In 1994 KEMA has started a project called: Quality of service. During the project different methods and techniques have been developed. In this paper three tools will be presented. The ``customer simulator``, the Dutch power quality monitoring programme and the ``PSQ-indicator``. (Author)

Economic and Nonproliferation Analysis Framework for Assessing Reliable Nuclear Fuel Service Arrangements

International Nuclear Information System (INIS)

Phillips, Jon R.; Kreyling, Sean J.; Short, Steven M.; Weimar, Mark R.

2010-01-01

Nuclear power is now broadly recognized as an essential technology in national strategies to provide energy security while meeting carbon management goals. Yet a long standing conundrum remains: how to enable rapid growth in the global nuclear power infrastructure while controlling the spread of sensitive enrichment and reprocessing technologies that lie at the heart of nuclear fuel supply and nuclear weapons programs. Reducing the latent proliferation risk posed by a broader horizontal spread of enrichment and reprocessing technology has been a primary goal of national nuclear supplier policies since the beginning of the nuclear power age. Attempts to control the spread of sensitive nuclear technology have been the subject of numerous initiatives in the intervening decades sometimes taking the form of calls to develop fuel supply and service assurances to reduce market pull to increase the number of states with fuel cycle capabilities. A clear understanding of what characteristics of specific reliable nuclear fuel service (RNFS) and supply arrangements qualify them as 'attractive offers' is critical to the success of current and future efforts. At a minimum, RNFS arrangements should provide economic value to all participants and help reduce latent proliferation risks posed by the global expansion of nuclear power. In order to inform the technical debate and the development of policy, Pacific Northwest National Laboratory has been developing an analytical framework to evaluate the economics and nonproliferation merits of alternative approaches to RNFS arrangements. This paper provides a brief overview of the economic analysis framework developed and applied to a model problem of current interest: full-service nuclear fuel leasing arrangements. Furthermore, this paper presents an extended outline of a proposed analysis approach to evaluate the non-proliferation merits of various RNFS alternatives.

Crisis Reliability Indicators Supporting Emergency Services (CRISES): A Framework for Developing Performance Measures for Behavioral Health Crisis and Psychiatric Emergency Programs.

Science.gov (United States)

Balfour, Margaret E; Tanner, Kathleen; Jurica, Paul J; Rhoads, Richard; Carson, Chris A

2016-01-01

Crisis and emergency psychiatric services are an integral part of the healthcare system, yet there are no standardized measures for programs providing these services. We developed the Crisis Reliability Indicators Supporting Emergency Services (CRISES) framework to create measures that inform internal performance improvement initiatives and allow comparison across programs. The framework consists of two components-the CRISES domains (timely, safe, accessible, least-restrictive, effective, consumer/family centered, and partnership) and the measures supporting each domain. The CRISES framework provides a foundation for development of standardized measures for the crisis field. This will become increasingly important as pay-for-performance initiatives expand with healthcare reform.

The Turkish adaptation of scale to measure patient perceptions of the quality of nursing care and related hospital services: A validity and reliability study.

Science.gov (United States)

Oren, Besey; Zengin, Neriman; Yildiz, Nebahat

2016-01-01

This study aimed to test the validity and reliability of a version of the tool developed in Sri Lanka in 2011 to assess patient perceptions of the quality of nursing care and related hospital services created for use with Turkish patients. This methodological study was conducted between November 2013 and November 2014 after obtaining ethical approval and organizational permission. Data was collected during discharge from 180 adult patients who were hospitalized for at least 3 days at a medical school hospital located in Istanbul. After language validation, validity and reliability analyses of the scale were conducted. Content validity, content validity index (CVI), construct validity, and exploratory factor analysis were assessed and examined, and reliability was tested using the Cronbach's alpha coefficient and item-total correlations. Mean CVI was found to be 0.95, which is above expected value. Exploratory factor analysis revealed 4 factors with eigenvalues above 1, which explained 82.4% of total variance in the Turkish version of the tool to measure patient perceptions of nursing care and other hospital services. Factor loading for each item was ≥.40. Cronbach's alpha coefficient of sub-dimensions and total scale were found to be 0.84-0.98 and 0.98, respectively. Item-total correlations ranged from 0.56 to 0.83 for the entire group, which was above expected values. The Turkish version of the scale to assess patient perceptions of the quality of nursing care and related hospital services, which comprised 4 sub-dimensions and 36 items, was found to be valid and reliable for use with the Turkish population.

An application of characteristic function in order to predict reliability and lifetime of aeronautical hardware

Energy Technology Data Exchange (ETDEWEB)

Żurek, Józef; Kaleta, Ryszard; Zieja, Mariusz [Air Force Institute of Technology ul. Księcia Bolesława 6 01-494 Warsaw (Poland)

2016-06-08

The forecasting of reliability and life of aeronautical hardware requires recognition of many and various destructive processes that deteriorate the health/maintenance status thereof. The aging of technical components of aircraft as an armament system proves of outstanding significance to reliability and safety of the whole system. The aging process is usually induced by many and various factors, just to mention mechanical, biological, climatic, or chemical ones. The aging is an irreversible process and considerably affects (i.e. reduces) reliability and lifetime of aeronautical equipment. Application of the characteristic function of the aging process is suggested to predict reliability and lifetime of aeronautical hardware. An increment in values of diagnostic parameters is introduced to formulate then, using the characteristic function and after some rearrangements, the partial differential equation. An analytical dependence for the characteristic function of the aging process is a solution to this equation. With the inverse transformation applied, the density function of the aging of aeronautical hardware is found. Having found the density function, one can determine the aeronautical equipment’s reliability and lifetime. The in-service collected or the life tests delivered data are used to attain this goal. Coefficients in this relationship are found using the likelihood function.

An application of characteristic function in order to predict reliability and lifetime of aeronautical hardware

International Nuclear Information System (INIS)

Żurek, Józef; Kaleta, Ryszard; Zieja, Mariusz

2016-01-01

The forecasting of reliability and life of aeronautical hardware requires recognition of many and various destructive processes that deteriorate the health/maintenance status thereof. The aging of technical components of aircraft as an armament system proves of outstanding significance to reliability and safety of the whole system. The aging process is usually induced by many and various factors, just to mention mechanical, biological, climatic, or chemical ones. The aging is an irreversible process and considerably affects (i.e. reduces) reliability and lifetime of aeronautical equipment. Application of the characteristic function of the aging process is suggested to predict reliability and lifetime of aeronautical hardware. An increment in values of diagnostic parameters is introduced to formulate then, using the characteristic function and after some rearrangements, the partial differential equation. An analytical dependence for the characteristic function of the aging process is a solution to this equation. With the inverse transformation applied, the density function of the aging of aeronautical hardware is found. Having found the density function, one can determine the aeronautical equipment’s reliability and lifetime. The in-service collected or the life tests delivered data are used to attain this goal. Coefficients in this relationship are found using the likelihood function.

Transmission reliability faces future challenges

International Nuclear Information System (INIS)

Beaty, W.

1993-01-01

The recently published Washington International Energy Group's 1993 Electric Utility Outlook states that nearly one-third (31 percent) of U.S. utility executives expect reliability to decrease in the near future. Electric power system stability is crucial to reliability. Stability analysis determines whether a system will stay intact under normal operating conditions, during minor disturbances such as load fluctuations, and during major disturbances when one or more parts of the system fails. All system elements contribute to reliability or the lack of it. However, this report centers on the transmission segment of the electric system. The North American Electric Reliability Council (NERC) says the transmission systems as planned will be adequate over the next 10 years. However, delays in building new lines and increasing demands for transmission services are serious concerns. Reliability concerns exist in the Mid-Continent Area Power Pool and the Mid-America Interconnected Network regions where transmission facilities have not been allowed to be constructed as planned. Portions of the transmission systems in other regions are loaded at or near their limits. NERC further states that utilities must be allowed to complete planned generation and transmission as scheduled. A reliable supply of electricity also depends on adhering to established operating criteria. Factors that could complicate operations include: More interchange schedules resulting from increased transmission services. Increased line loadings in portions of the transmission systems. Proliferation of non-utility generators

Application of reliability methods in Ontario Hydro

International Nuclear Information System (INIS)

Jeppesen, R.; Ravishankar, T.J.

1985-01-01

Ontario Hydro have established a reliability program in support of its substantial nuclear program. Application of the reliability program to achieve both production and safety goals is described. The value of such a reliability program is evident in the record of Ontario Hydro's operating nuclear stations. The factors which have contributed to the success of the reliability program are identified as line management's commitment to reliability; selective and judicious application of reliability methods; establishing performance goals and monitoring the in-service performance; and collection, distribution, review and utilization of performance information to facilitate cost-effective achievement of goals and improvements. (orig.)

Adolescent Aggression and Differentiation of Self: Guided Mindfulness Meditation in the Service of Individuation

Directory of Open Access Journals (Sweden)

Liora Birnbaum

2005-01-01

Full Text Available This paper presents adolescent aggression as mediated by the level of differentiation of self. No research has directly addressed Bowen's notion that level of differentiation impacts child functioning including aggression. Level of differentiation is discussed in conjunction with social, gender and cultural norms as manifested in aggressive behavior. Female adolescent aggression is described as mainly relationship focused and expressed via verbal threats, intimidation and manipulation, while male aggression is described mainly as overt physical violence involving dominance and competitiveness. Research on differentiation focuses mainly on Western cultures that tend to be individualistic. Jewish-Israeli society is in transition from collectivistic to individualistic cultural values in the midst of ongoing hostilities. These processes create conflict regarding togetherness and individuality needs among adolescents, who are exposed to contradictory messages regarding separating and staying close. External as well as internal expressions of aggression (depression, suicide are presented as coping strategies in the service of a wounded self-negotiating with the world. Guided mindfulness meditation is a powerful technique for facilitating healing and growth toward autonomy by helping adolescents connect to their inner voice. This technique may be especially useful in the adolescent search for self-awareness, meaning and life purpose. Bodily, cognitive and emotional experiences are treated as informative regarding the “self” and facilitate expansion of self-perception and individuality.

Adolescent aggression and differentiation of self: guided mindfulness meditation in the service of individuation.

Science.gov (United States)

Birnbaum, Liora

2005-06-23

This paper presents adolescent aggression as mediated by the level of differentiation of self. No research has directly addressed Bowen's notion that level of differentiation impacts child functioning including aggression. Level of differentiation is discussed in conjunction with social, gender and cultural norms as manifested in aggressive behavior. Female adolescent aggression is described as mainly relationship focused and expressed via verbal threats, intimidation and manipulation, while male aggression is described mainly as overt physical violence involving dominance and competitiveness. Research on differentiation focuses mainly on Western cultures that tend to be individualistic. Jewish-Israeli society is in transition from collectivistic to individualistic cultural values in the midst of ongoing hostilities. These processes create conflict regarding togetherness and individuality needs among adolescents, who are exposed to contradictory messages regarding separating and staying close. External as well as internal expressions of aggression (depression, suicide) are presented as coping strategies in the service of a wounded self-negotiating with the world. Guided mindfulness meditation is a powerful technique for facilitating healing and growth toward autonomy by helping adolescents connect to their inner voice. This technique may be especially useful in the adolescent search for self-awareness, meaning and life purpose. Bodily, cognitive and emotional experiences are treated as informative regarding the 'self' and facilitate expansion of self-perception and individuality.

Customer control and evaluation of service validity and reliability

NARCIS (Netherlands)

van Raaij, W. Fred; Pruyn, Adriaan T.H.

1998-01-01

A control and attribution model of service production and evaluation is proposed. Service production consists of the stages specification (input), realization (throughput), and outcome (output). Customers may exercise control over all three stages of the service. Critical factors of service

Integration of nondestructive examination reliability and fracture mechanics

International Nuclear Information System (INIS)

Doctor, S.R.; Bates, D.J.; Charlot, L.A.

1985-01-01

The primary pressure boundaries (pressure vessels and piping) of nuclear power plants are in-service inspected (ISI) according to the rules of ASME Boiler and Pressure Vessel Code, Section XI. Ultrasonic techniques are normally used for these inspections, which are periodically performed on a sampling of welds. The Integration of Nondestructive Examination (NDE) Reliability and Fracture Mechanics (FM) Program at Pacific Northwest Laboratory was established to determine the reliability of current ISI techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this NRC program are to: 1) determine the reliability of ultrasonic ISI performed on commercial light-water reactor primary systems; 2) using probabilistic FM analysis, determine the impact of NDE unreliability on system safety and determine the level of inspection reliability required to ensure a suitably low failure probability; 3) evaluate the degree of reliability improvement that could be achieved using improved and advanced NDE techniques; and 4) based on material properties, service conditions, and NDE uncertainties, formulate recommended revisions to ASME Code, Section XI, and Regulatory Requirements needed to ensure suitably low failure probabilities

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

Test-retest reliability and agreement of the Satisfaction with the Assistive Technology Services (SATS) instrument in two Nordic countries.

Science.gov (United States)

Sund, Terje; Iwarsson, Susanne; Anttila, Heidi; Helle, Tina; Brandt, Ase

2014-07-01

The purpose of this study was to investigate test-retest reliability, agreement, internal consistency, and floor- and ceiling effects of the Danish and Finnish versions of the Satisfaction with the Assistive Technology Services (SATS) instrument among adult users of powered wheelchairs (PWCs) or powered scooters (scooters). Test-retest design, two telephone interviews 7-18 days apart of 40 informants, with mean age of 67.5 (SD 13.09) years in the Danish; and 54 informants with mean age of 55.6 (SD 12.09) years in the Finnish sample. The intra-class correlation coefficient varied between 0.57 and 0.93 for items in the Danish and between 0.41 and 0.93 in the Finnish sample. The percentage agreement varied between 54.2 and 79.5 for items in the Danish and between 69.2 and 81.1 in the Finnish sample, while the Cronbach's alpha values varied between 0.87 and 0.96 in the two samples. A ceiling effect was found in all items of both samples. This study indicates that the SATS may be reliably administered for telephone interviews among adult PWC and scooter users, and give information about aspects of the service delivery process for quality development improvement purposes. Further psychometric testing of the SATS is required.

Dynamic quality of service differentiation using fixed code weight in optical CDMA networks

Science.gov (United States)

Kakaee, Majid H.; Essa, Shawnim I.; Abd, Thanaa H.; Seyedzadeh, Saleh

2015-11-01

The emergence of network-driven applications, such as internet, video conferencing, and online gaming, brings in the need for a network the environments with capability of providing diverse Quality of Services (QoS). In this paper, a new code family of novel spreading sequences, called a Multi-Service (MS) code, has been constructed to support multiple services in Optical- Code Division Multiple Access (CDMA) system. The proposed method uses fixed weight for all services, however reducing the interfering codewords for the users requiring higher QoS. The performance of the proposed code is demonstrated using mathematical analysis. It shown that the total number of served users with satisfactory BER of 10-9 using NB=2 is 82, while they are only 36 and 10 when NB=3 and 4 respectively. The developed MS code is compared with variable-weight codes such as Variable Weight-Khazani Syed (VW-KS) and Multi-Weight-Random Diagonal (MW-RD). Different numbers of basic users (NB) are used to support triple-play services (audio, data and video) with different QoS requirements. Furthermore, reference to the BER of 10-12, 10-9, and 10-3 for video, data and audio, respectively, the system can support up to 45 total users. Hence, results show that the technique can clearly provide a relative QoS differentiation with lower value of basic users can support larger number of subscribers as well as better performance in terms of acceptable BER of 10-9 at fixed code weight.

Green Data Gathering under Delay Differentiated Services Constraint for Internet of Things

Directory of Open Access Journals (Sweden)

Mingfeng Huang

2018-01-01

Full Text Available Energy-efficient data gathering techniques play a crucial role in promoting the development of smart portable devices as well as smart sensor devices based Internet of Things (IoT. For data gathering, different applications require different delay constraints; therefore, a delay Differentiated Services based Data Routing (DSDR scheme is creatively proposed to improve the delay differentiated services constraint that is missed from previous data gathering studies. The DSDR scheme has three advantages: first, DSDR greatly reduces transmission delay by establishing energy-efficient routing paths (E2RPs. Multiple E2RPs are established in different locations of the network to forward data, and the duty cycles of nodes on E2RPs are increased to 1, so the data is forwarded by E2RPs without the existence of sleeping delay, which greatly reduces transmission latency. Secondly, DSDR intelligently chooses transmission method according to data urgency: the direct-forwarding strategy is adopted for delay-sensitive data to ensure minimum end-to-end delay, while wait-forwarding method is adopted for delay-tolerant data to perform data fusion for reducing energy consumption. Finally, DSDR make full use of the residual energy and improve the effective energy utilization. The E2RPs are built in the region with adequate residual energy and they are periodically rotated to equalize the energy consumption of the network. A comprehensive performance analysis demonstrates that the DSDR scheme has obvious advantages in improving network performance compared to previous studies: it reduces transmission latency of delay-sensitive data by 44.31%, reduces transmission latency of delay-tolerant data by 25.65%, and improves network energy utilization by 30.61%, while also guaranteeing the network lifetime is not lower than previous studies.

A study in the reliability analysis method for nuclear power plant structures (I)

Energy Technology Data Exchange (ETDEWEB)

Oh, Byung Hwan; Choi, Seong Cheol; Shin, Ho Sang; Yang, In Hwan; Kim, Yi Sung; Yu, Young; Kim, Se Hun [Seoul, Nationl Univ., Seoul (Korea, Republic of)

1999-03-15

Nuclear power plant structures may be exposed to aggressive environmental effects that may cause their strength and stiffness to decrease over their service life. Although the physics of these damage mechanisms are reasonably well understood and quantitative evaluation of their effects on time-dependent structural behavior is possible in some instances, such evaluations are generally very difficult and remain novel. The assessment of existing steel containment in nuclear power plants for continued service must provide quantitative evidence that they are able to withstand future extreme loads during a service period with an acceptable level of reliability. Rational methodologies to perform the reliability assessment can be developed from mechanistic models of structural deterioration, using time-dependent structural reliability analysis to take loading and strength uncertainties into account. The final goal of this study is to develop the analysis method for the reliability of containment structures. The cause and mechanism of corrosion is first clarified and the reliability assessment method has been established. By introducing the equivalent normal distribution, the procedure of reliability analysis which can determine the failure probabilities has been established. The influence of design variables to reliability and the relation between the reliability and service life will be continued second year research.

A damage mechanics based approach to structural deterioration and reliability

Energy Technology Data Exchange (ETDEWEB)

Bhattcharya, B.; Ellingwood, B. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Civil Engineering

1998-02-01

Structural deterioration often occurs without perceptible manifestation. Continuum damage mechanics defines structural damage in terms of the material microstructure, and relates the damage variable to the macroscopic strength or stiffness of the structure. This enables one to predict the state of damage prior to the initiation of a macroscopic flaw, and allows one to estimate residual strength/service life of an existing structure. The accumulation of damage is a dissipative process that is governed by the laws of thermodynamics. Partial differential equations for damage growth in terms of the Helmholtz free energy are derived from fundamental thermodynamical conditions. Closed-form solutions to the equations are obtained under uniaxial loading for ductile deformation damage as a function of plastic strain, for creep damage as a function of time, and for fatigue damage as function of number of cycles. The proposed damage growth model is extended into the stochastic domain by considering fluctuations in the free energy, and closed-form solutions of the resulting stochastic differential equation are obtained in each of the three cases mentioned above. A reliability analysis of a ring-stiffened cylindrical steel shell subjected to corrosion, accidental pressure, and temperature is performed.

A damage mechanics based approach to structural deterioration and reliability

International Nuclear Information System (INIS)

Bhattcharya, B.; Ellingwood, B.

1998-02-01

Structural deterioration often occurs without perceptible manifestation. Continuum damage mechanics defines structural damage in terms of the material microstructure, and relates the damage variable to the macroscopic strength or stiffness of the structure. This enables one to predict the state of damage prior to the initiation of a macroscopic flaw, and allows one to estimate residual strength/service life of an existing structure. The accumulation of damage is a dissipative process that is governed by the laws of thermodynamics. Partial differential equations for damage growth in terms of the Helmholtz free energy are derived from fundamental thermodynamical conditions. Closed-form solutions to the equations are obtained under uniaxial loading for ductile deformation damage as a function of plastic strain, for creep damage as a function of time, and for fatigue damage as function of number of cycles. The proposed damage growth model is extended into the stochastic domain by considering fluctuations in the free energy, and closed-form solutions of the resulting stochastic differential equation are obtained in each of the three cases mentioned above. A reliability analysis of a ring-stiffened cylindrical steel shell subjected to corrosion, accidental pressure, and temperature is performed

A Novel Reliability Enhanced Handoff Method in Future Wireless Heterogeneous Networks

Directory of Open Access Journals (Sweden)

Wang YuPeng

2016-01-01

Full Text Available As the demand increases, future networks will follow the trends of network variety and service flexibility, which requires heterogeneous type of network deployment and reliable communication method. In practice, most communication failure happens due to the bad radio link quality, i.e., high-speed users suffers a lot on the problem of radio link failure, which causes the problem of communication interrupt and radio link recovery. To make the communication more reliable, especially for the high mobility users, we propose a novel communication handoff mechanism to reduce the occurrence of service interrupt. Based on computer simulation, we find that the reliability on the service is greatly improved.

Verification criteria on the reliability of personal dosimetric services from x and gamma radiations; Criteri per la verifica dell'affidabilita di un servizio di dosimetria personale per radiazioni x e gamma

Energy Technology Data Exchange (ETDEWEB)

Borasi, G [Arcisp. S. Maria Nuova, USL 9, Reggio Emilia (Italy); Benco, A [CCE-CCR, Ispra, Varese (Italy); Kaftal, S [CESNEF - Politecnico, Milan (Italy)

1990-07-15

The paper presents the methods used by Working Group ENEA-EDP (Experts in Personal Dosimetry) to control the reliability of the Dosimetric Services operating in Italy and asking for the above controls on voluntary basis. Testing and irradiation test methods are explained as well as the evaluation criteria. The paper includes suggestions and guide-lines to gain the status of 'Reliable Service'. Technical equipment and operating procedures needed to pass the test are also illustrated. (author)

Redefining reliability

International Nuclear Information System (INIS)

Paulson, S.L.

1995-01-01

Want to buy some reliability? The question would have been unthinkable in some markets served by the natural gas business even a few years ago, but in the new gas marketplace, industrial, commercial and even some residential customers have the opportunity to choose from among an array of options about the kind of natural gas service they need--and are willing to pay for. The complexities of this brave new world of restructuring and competition have sent the industry scrambling to find ways to educate and inform its customers about the increased responsibility they will have in determining the level of gas reliability they choose. This article discusses the new options and the new responsibilities of customers, the needed for continuous education, and MidAmerican Energy Company's experiment in direct marketing of natural gas

Reliability-based condition assessment of steel containment and liners

International Nuclear Information System (INIS)

Ellingwood, B.; Bhattacharya, B.; Zheng, R.

1996-11-01

Steel containments and liners in nuclear power plants may be exposed to aggressive environments that may cause their strength and stiffness to decrease during the plant service life. Among the factors recognized as having the potential to cause structural deterioration are uniform, pitting or crevice corrosion; fatigue, including crack initiation and propagation to fracture; elevated temperature; and irradiation. The evaluation of steel containments and liners for continued service must provide assurance that they are able to withstand future extreme loads during the service period with a level of reliability that is sufficient for public safety. Rational methodologies to provide such assurances can be developed using modern structural reliability analysis principles that take uncertainties in loading, strength, and degradation resulting from environmental factors into account. The research described in this report is in support of the Steel Containments and Liners Program being conducted for the US Nuclear Regulatory Commission by the Oak Ridge National Laboratory. The research demonstrates the feasibility of using reliability analysis as a tool for performing condition assessments and service life predictions of steel containments and liners. Mathematical models that describe time-dependent changes in steel due to aggressive environmental factors are identified, and statistical data supporting the use of these models in time-dependent reliability analysis are summarized. The analysis of steel containment fragility is described, and simple illustrations of the impact on reliability of structural degradation are provided. The role of nondestructive evaluation in time-dependent reliability analysis, both in terms of defect detection and sizing, is examined. A Markov model provides a tool for accounting for time-dependent changes in damage condition of a structural component or system. 151 refs

Long term reliability analysis of standby diesel generators

International Nuclear Information System (INIS)

Winfield, D.J.

1988-01-01

The long term reliability of 11 diesel generators of 125 to 250 kV A size has been analysed from 26 years of data base information on individual diesel service as standby power supplies for the Chalk River research reactor facilities. Failure to start on demand and failure to run data is presented and failure by diesel subsystem and multiple failures are also analysed. A brief comparison is made with reliability studies of larger diesel generator units used for standby power service in nuclear power plants. (author)

A differentiated approach to service recovery

NARCIS (Netherlands)

Boshoff, C.; Peelen, E.; Hoogendoorn, M.; Kraan, van der Y.

2005-01-01

It appears that service failures, like the poor, will always be with us. Almost all “moments of truth” service encounters are vulnerable to breakdowns. Handling complaints and resolving problems then become important activities to retain customers and to avoid undesirable outcomes such as negative

Reliability-based assessment of polyethylene pipe creep lifetime

International Nuclear Information System (INIS)

Khelif, Rabia; Chateauneuf, Alaa; Chaoui, Kamel

2007-01-01

Lifetime management of underground pipelines is mandatory for safe hydrocarbon transmission and distribution systems. The use of high-density polyethylene tubes subjected to internal pressure, external loading and environmental variations requires a reliability study in order to define the service limits and the optimal operating conditions. In service, the time-dependent phenomena, especially creep, take place during the pipe lifetime, leading to significant strength reduction. In this work, the reliability-based assessment of pipe lifetime models is carried out, in order to propose a probabilistic methodology for lifetime model selection and to determine the pipe safety levels as well as the most important parameters for pipeline reliability. This study is enhanced by parametric analysis on pipe configuration, gas pressure and operating temperature

Reliability-based assessment of polyethylene pipe creep lifetime

Energy Technology Data Exchange (ETDEWEB)

Khelif, Rabia [LaMI-UBP and IFMA, Campus de Clermont-Fd, Les Cezeaux, BP 265, 63175 Aubiere Cedex (France); LR3MI, Departement de Genie Mecanique, Universite Badji Mokhtar, BP 12, Annaba 23000 (Algeria)], E-mail: rabia.khelif@ifma.fr; Chateauneuf, Alaa [LGC-University Blaise Pascal, Campus des Cezeaux, BP 206, 63174 Aubiere Cedex (France)], E-mail: alaa.chateauneuf@polytech.univ-bpclermont.fr; Chaoui, Kamel [LR3MI, Departement de Genie Mecanique, Universite Badji Mokhtar, BP 12, Annaba 23000 (Algeria)], E-mail: chaoui@univ-annaba.org

2007-12-15

Lifetime management of underground pipelines is mandatory for safe hydrocarbon transmission and distribution systems. The use of high-density polyethylene tubes subjected to internal pressure, external loading and environmental variations requires a reliability study in order to define the service limits and the optimal operating conditions. In service, the time-dependent phenomena, especially creep, take place during the pipe lifetime, leading to significant strength reduction. In this work, the reliability-based assessment of pipe lifetime models is carried out, in order to propose a probabilistic methodology for lifetime model selection and to determine the pipe safety levels as well as the most important parameters for pipeline reliability. This study is enhanced by parametric analysis on pipe configuration, gas pressure and operating temperature.

power system reliability in supplying nuclear reactors

International Nuclear Information System (INIS)

Gad, M.M.M.

2007-01-01

this thesis presents a simple technique for deducing minimal cut set (MCS) from the defined minimal path set (MPS) of generic distribution system and this technique have been used to evaluate the basic reliability indices of Egypt's second research reactor (ETRR-2) electrical distribution network. the alternative system configurations are then studied to evaluate their impact on service reliability. the proposed MCS approach considers both sustained and temporary outage. the temporary outage constitutes an important parameter in characterizing the system reliability indices for critical load point in distribution system. it is also consider the power quality impact on the reliability indices

Implementasi Wireless Quality of Service dengan Metode Load Switching Jaringan Seluler Menggunakan Software Defined Network untuk Meningkatkan Network Reliability pada Jaringan Dinamis

Directory of Open Access Journals (Sweden)

Yoga Bayu Aji Pranawa

2017-03-01

Full Text Available Wireless Quality of Service (QOS adalah salah satu dimensi mobilitas, yaitu sebuah metode yang digunakan untuk menjaga kualitas suatu jaringan nirkabel. QOS diperlukan sebagai sebuah metode untuk memenuhi kriteria pelayanan sistem bagi pengguna, yaitu confidentiality, integrity, dan availability. Beberapa aspek yang menjadi topik utama dalam QOS adalah failure and recovery mechanism, variable bandwidth, computing distribution, discovery mechanism, variable lantency, dan performance feedback. Wireless yang dibahas pada penelitian ini dititik beratkan pada jaringan seluler yang cenderung tidak reliable pada daerah tertentu. Oleh karena itu dibutuhkan sebuah mekanisme yang dapat mengatasi tidak stabilnya jaringan seluler tersebut. mplementasi mekanisme yang diterapkan pada penelitian ini adalah dengan menerapkan load switching pada jaringan seluler dengan menggunakan beberapa provider dan menerapkan teknologi Software Defined Network (SDN. Berdasarkan hasi uji coba dapat disimpulkan bahwa sistem yang dibuat pada penelitian ini dapat menerapkan wireless quality of service dan meningkatkan network reliability sebesar 65,29% dan 83,87% lebih baik untuk penggunaan tanpa waktu tunggu dan dengan waktu tunggu pada suatu jaringan  dinamis.

Estimating the Reliability of the Elements of Cloud Services

Directory of Open Access Journals (Sweden)

Iuliia V. Ignatova

2017-01-01

Full Text Available Cloud technologies are a very considerable area that influence IT infrastructure, network services and applications. Research has highlighted difficulties in the functioning of cloud infrastructure. For instance, if a server is subjected to malicious attacks or a force majeure causes a failure in the cloud's service, it is required to determine the time that it takes the system to return to being fully functional after the crash. This will determine the technological and financial risks faced by the owner and end users of cloud services. Therefore, to solve the problem of determining the expected time before service is resumed after a failure, we propose to apply Markovian queuing systems, specifically a model of a multi-channel queuing system with Poisson input flow and denial-of-service (breakdown. (original abstract

Reliability and Validity of Survey Instruments to Measure Work-Related Fatigue in the Emergency Medical Services Setting: A Systematic Review.

Science.gov (United States)

Patterson, P Daniel; Weaver, Matthew D; Fabio, Anthony; Teasley, Ellen M; Renn, Megan L; Curtis, Brett R; Matthews, Margaret E; Kroemer, Andrew J; Xun, Xiaoshuang; Bizhanova, Zhadyra; Weiss, Patricia M; Sequeira, Denisse J; Coppler, Patrick J; Lang, Eddy S; Higgins, J Stephen

2018-02-15

This study sought to systematically search the literature to identify reliable and valid survey instruments for fatigue measurement in the Emergency Medical Services (EMS) occupational setting. A systematic review study design was used and searched six databases, including one website. The research question guiding the search was developed a priori and registered with the PROSPERO database of systematic reviews: "Are there reliable and valid instruments for measuring fatigue among EMS personnel?" (2016:CRD42016040097). The primary outcome of interest was criterion-related validity. Important outcomes of interest included reliability (e.g., internal consistency), and indicators of sensitivity and specificity. Members of the research team independently screened records from the databases. Full-text articles were evaluated by adapting the Bolster and Rourke system for categorizing findings of systematic reviews, and the rated data abstracted from the body of literature as favorable, unfavorable, mixed/inconclusive, or no impact. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology was used to evaluate the quality of evidence. The search strategy yielded 1,257 unique records. Thirty-four unique experimental and non-experimental studies were determined relevant following full-text review. Nineteen studies reported on the reliability and/or validity of ten different fatigue survey instruments. Eighteen different studies evaluated the reliability and/or validity of four different sleepiness survey instruments. None of the retained studies reported sensitivity or specificity. Evidence quality was rated as very low across all outcomes. In this systematic review, limited evidence of the reliability and validity of 14 different survey instruments to assess the fatigue and/or sleepiness status of EMS personnel and related shift worker groups was identified.

Integration of NDE Reliability and Fracture Mechanics

Energy Technology Data Exchange (ETDEWEB)

Becker, F. L.; Doctor, S. R.; Heas!er, P. G.; Morris, C. J.; Pitman, S. G.; Selby, G. P.; Simonen, F. A.

1981-03-01

The Pacific Northwest Laboratory is conducting a four-phase program for measuring and evaluating the effectiveness and reliability of in-service inspection (lSI} performed on the primary system piping welds of commercial light water reactors (LWRs). Phase I of the program is complete. A survey was made of the state of practice for ultrasonic rsr of LWR primary system piping welds. Fracture mechanics calculations were made to establish required nondestrutive testing sensitivities. In general, it was found that fatigue flaws less than 25% of wall thickness would not grow to failure within an inspection interval of 10 years. However, in some cases failure could occur considerably faster. Statistical methods for predicting and measuring the effectiveness and reliability of lSI were developed and will be applied in the "Round Robin Inspections" of Phase II. Methods were also developed for the production of flaws typical of those found in service. Samples fabricated by these methods wilI be used in Phase II to test inspection effectiveness and reliability. Measurements were made of the influence of flaw characteristics {i.e., roughness, tightness, and orientation) on inspection reliability. These measurernents, as well as the predictions of a statistical model for inspection reliability, indicate that current reporting and recording sensitivities are inadequate.

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)

Long-term reliability evaluation of nuclear containments with tendon force degradation

International Nuclear Information System (INIS)

Kim, Sang-Hyo; Choi, Moon-Seock; Joung, Jung-Yeun; Kim, Kun-Soo

2013-01-01

Highlights: • A probabilistic model on long-term degradation of tendon force is developed. • By using the model, we performed reliability evaluation of nuclear containment. • The analysis is also performed for the case with the strict maintenance programme. • We showed how to satisfy the target safety in the containments facing life extension. - Abstract: The long-term reliability of nuclear containment is important for operating nuclear power plants. In particular, long-term reliability should be clarified when the service life of nuclear containment is being extended. This study focuses not only on determining the reliability of nuclear containment but also presenting the reliability improvement by strengthening the containment itself or by running a strict maintenance programme. The degradation characteristics of tendon force are estimated from the data recorded during in-service inspection of containments. A reliability analysis is conducted for a limit state of through-wall cracking, which is conservative, but most crucial limit state. The results of this analysis indicate that reliability is the lowest at 3/4 height of the containment wall. Therefore, this location is the most vulnerable for the specific limit state considered in this analysis. Furthermore, changes in structural reliability owing to an increase in the number of inspecting tendons are analysed for verifying the effect of the maintenance program's intensity on expected containment reliability. In the last part of this study, an example of obtaining target reliability of nuclear containment by strengthening its structural resistance is presented. A case study is conducted for exemplifying the effect of strengthening work on containment reliability, especially during extended service life

Dynamic reliability and risk assessment of the accident localization system of the Ignalina NPP RBMK-1500 reactor

International Nuclear Information System (INIS)

Kopustinskas, V.; Augutis, J.; Rimkevicius, S.

2005-01-01

The paper presents reliability and risk analysis of the RBMK-1500 reactor accident localization system (ALS) (confinement), which prevents radioactive releases to the environment. Reliability of the system was estimated and compared by two methods: the conventional fault tree method and an innovative dynamic reliability model, based on stochastic differential equations. Frequency of radioactive release through ALS was also estimated. The results of the study indicate that conventional fault tree modeling techniques in this case apply high degree of conservatism in the system reliability estimates. One of the purposes of the ALS reliability study was to demonstrate advantages of the dynamic reliability analysis against the conventional fault/event tree methods. The Markovian framework to deal with dynamic aspects of system behavior is presented. Although not analyzed in detail, the framework is also capable of accounting for non-constant component failure rates. Computational methods are proposed to solve stochastic differential equations, including analytical solution, which is possible only for relatively small and simple systems. Other numerical methods, like Monte Carlo and numerical schemes of differential equations are analyzed and compared. The study is finalized with concluding remarks regarding both the studied system reliability and computational methods used

Addressing Uniqueness and Unison of Reliability and Safety for a Better Integration

Science.gov (United States)

Huang, Zhaofeng; Safie, Fayssal

2016-01-01

Over time, it has been observed that Safety and Reliability have not been clearly differentiated, which leads to confusion, inefficiency, and, sometimes, counter-productive practices in executing each of these two disciplines. It is imperative to address this situation to help Reliability and Safety disciplines improve their effectiveness and efficiency. The paper poses an important question to address, "Safety and Reliability - Are they unique or unisonous?" To answer the question, the paper reviewed several most commonly used analyses from each of the disciplines, namely, FMEA, reliability allocation and prediction, reliability design involvement, system safety hazard analysis, Fault Tree Analysis, and Probabilistic Risk Assessment. The paper pointed out uniqueness and unison of Safety and Reliability in their respective roles, requirements, approaches, and tools, and presented some suggestions for enhancing and improving the individual disciplines, as well as promoting the integration of the two. The paper concludes that Safety and Reliability are unique, but compensating each other in many aspects, and need to be integrated. Particularly, the individual roles of Safety and Reliability need to be differentiated, that is, Safety is to ensure and assure the product meets safety requirements, goals, or desires, and Reliability is to ensure and assure maximum achievability of intended design functions. With the integration of Safety and Reliability, personnel can be shared, tools and analyses have to be integrated, and skill sets can be possessed by the same person with the purpose of providing the best value to a product development.

Guarantee of reliability of devices complexes for plastic tube welding

International Nuclear Information System (INIS)

Voskresenskij, L.A.; Zajtsev, A.I.; Nelyubov, V.I.; Fedorov, M.A.

1988-01-01

Results of calculations and experimental studies on providing reliability of complex for plastic tube welding are presented. Choice of reliability indeces and standards is based. Reliability levels of components are determined. The most waded details are calculated. It is shown that they meet the reqrurements of strength and reliability. Service life tests supported the correct choice of springs. Recommendations on elevating reliability are given. Directions of further developments are shown. 8 refs.; 2 figs.; 1 tab

Interoperability of Integrated Services and Differentiated Services architectures

NARCIS (Netherlands)

Rexhepi, Vlora; Heijenk, Geert

2000-01-01

The current trends in the development of real-time Internet applications and the rapid growth of mobile systems, indicate that the future Internet architecture will have to support various applications with different Quality of Service (QoS) requirements, regardless of whether they are running on a

Parametric Mass Reliability Study

Science.gov (United States)

Holt, James P.

2014-01-01

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

Reliability Evaluation on Creep Life Prediction of Alloy 617 for a Very High Temperature Reactor

International Nuclear Information System (INIS)

Kim, Woo-Gon; Hong, Sung-Deok; Kim, Yong-Wan; Park, Jae-Young; Kim, Seon-Jin

2012-01-01

This paper evaluates the reliability of creep rupture life under service conditions of Alloy 617, which is considered as one of the candidate materials for use in a very high temperature reactor (VHTR) system. A Z-parameter, which represents the deviation of creep rupture data from the master curve, was used for the reliability analysis of the creep rupture data of Alloy 617. A Service-condition Creep Rupture Interference (SCRI) model, which can consider both the scattering of the creep rupture data and the fluctuations of temperature and stress under any service conditions, was also used for evaluating the reliability of creep rupture life. The statistical analysis showed that the scattering of creep rupture data based on Z-parameter was supported by normal distribution. The values of reliability decreased rapidly with increasing amplitudes of temperature and stress fluctuations. The results established that the reliability decreased with an increasing service time.

Evaluating the Validity and Reliability of Customer Quality Questionnaire from the Experts’ and Customers’ Perspective in Services Related to Patients With Inflammatory Bowel Disease

Directory of Open Access Journals (Sweden)

Roya Hasanzadeh

2015-08-01

Full Text Available ​ Background and Objectives : Customer Quality refers to   customers’ capabilities to be effectively participating in service delivery and correct care processes. The aim of this study was to evaluate the validity and reliability of customer quality questionnaire in services related to  patients with Inflammatory Bowel Disease. Material and Methods : This is a qualitative study with the aim of assessment of customer quality questionnaire with 16 questions. This questionnaire was distributed among 11 experts to determine the validity of the questionnaire. Finally, 10 of them expressed their own opinions based on the criteria of validity and in the face validity section , they expressed their opinions qualitatively. Also, reliability of questionnaire was reviewed with 30 samples, according to the internal consistency. Results : In determining the content validity, all the questionnaire items were confirmed by CVR (1 and CVI (0.89 indicators. Also, reliability of the questionnaire was confirmed by Cronbach’s alpha (α=0.78.The final questionnaire was changed according to the experts’ recommendations and their qualitative comments on the 19 questions in four stages of customer quality, including: a the patient’s belief that his/her role in care process is important, b having knowledge, skill and confidence to take action in the care process, c  taking action to protect and improve the health or active involvement, d continuity of care, even in critical situations and under stress. Conclusion : Confirmation of the questionnaire with statistical scientific methods showed that this questionnaire is a very strong tool that using it in research can be an effective step in order to improve the quality of health services.

Changes in Differentiation-Relatedness During Psychoanalysis.

Science.gov (United States)

Calamaras, Martha R; Reviere, Susan L; Gallagher, Kathryn E; Kaslow, Nadine J

2016-01-01

This study sought to determine (a) if the Differentiation-Relatedness Scale of Self and Object Representations (D-RS), a coding model used with the Object Relations Inventory (Blatt, Wein, Chevron, & Quinlan, 1979 ) could be reliably applied to transcripts of psychoanalyses, and (b) if levels of differentiation-relatedness improve over the course of psychoanalysis. Participants were 4 creative writers who underwent psychoanalysis as part of a longitudinal research project focused on the processes and outcomes of psychoanalysis. Transcripts from the beginning and termination phases of psychoanalysis were coded by 2 independent raters for global, low, and high levels of self and other differentiation-relatedness and compared. There was good interrater agreement, suggesting that, like other forms of narrative material, psychoanalysis transcripts can be reliably rated for levels of object relations. Analysands showed an increase in global levels of differentiation-relatedness from a predominance of emergent ambivalent constancy (M = 6.2) at the beginning of analysis to consolidated, constant representations of self and other (M = 7.5) at the end of analysis. These preliminary findings contribute significantly to the empirical literature with regard to the measurement of self and object representations and change in these representations over the course of psychoanalysis.

System reliability developments in structural engineering

International Nuclear Information System (INIS)

Moses, F.

1982-01-01

Two major limitations occur in present structural design code developments utilizing reliability theory. The notional system reliabilities may differ significantly from calibrated component reliabilities. Secondly, actual failures are often due to gross errors not reflected in most present code formats. A review is presented of system reliability methods and further new concepts are developed. The incremental load approach for identifying and expressing collapse modes is expanded by employing a strategy to identify and enumerate the significant structural collapse modes. It further isolates the importance of critical components in the system performance. Ductile and brittle component behavior and strength correlation is reflected in the system model and illustrated in several examples. Modal combinations for the system reliability are also reviewed. From these developments a system factor can be addended to component safety checking equations. Values may be derived from system behavior by substituting in a damage model which accounts for the response range from component failure to collapse. Other strategies are discussed which emphasize quality assurance during design and in-service inspection for components whose behavior is critical to the system reliability. (Auth.)

SLA-aware differentiated QoS in elastic optical networks

Science.gov (United States)

Agrawal, Anuj; Vyas, Upama; Bhatia, Vimal; Prakash, Shashi

2017-07-01

The quality of service (QoS) offered by optical networks can be improved by accurate provisioning of service level specifications (SLSs) included in the service level agreement (SLA). A large number of users coexisting in the network require different services. Thus, a pragmatic network needs to offer a differentiated QoS to a variety of users according to the SLA contracted for different services at varying costs. In conventional wavelength division multiplexed (WDM) optical networks, service differentiation is feasible only for a limited number of users because of its fixed-grid structure. Newly introduced flex-grid based elastic optical networks (EONs) are more adaptive to traffic requirements as compared to the WDM networks because of the flexibility in their grid structure. Thus, we propose an efficient SLA provisioning algorithm with improved QoS for these flex-grid EONs empowered by optical orthogonal frequency division multiplexing (O-OFDM). The proposed algorithm, called SLA-aware differentiated QoS (SADQ), employs differentiation at the level of routing, spectrum allocation, and connection survivability. The proposed SADQ aims to accurately provision the SLA using such multilevel differentiation with an objective to improve the spectrum utilization from the network operator's perspective. SADQ is evaluated for three different CoSs under various traffic demand patterns and for different ratios of the number of requests belonging to the three considered CoSs. We propose two new SLA metrics for the improvement of functional QoS requirements, namely, security, confidentiality and survivability of high class of service (CoS) traffic. Since, to the best of our knowledge, the proposed SADQ is the first scheme in optical networks to employ exhaustive differentiation at the levels of routing, spectrum allocation, and survivability in a single algorithm, we first compare the performance of SADQ in EON and currently deployed WDM networks to assess the

Reliability and continuous regeneration model

Directory of Open Access Journals (Sweden)

Anna Pavlisková

2006-06-01

Full Text Available The failure-free function of an object is very important for the service. This leads to the interest in the determination of the object reliability and failure intensity. The reliability of an element is defined by the theory of probability.The element durability T is a continuous random variate with the probability density f. The failure intensity (tλ is a very important reliability characteristics of the element. Often it is an increasing function, which corresponds to the element ageing. We disposed of the data about a belt conveyor failures recorded during the period of 90 months. The given ses behaves according to the normal distribution. By using a mathematical analysis and matematical statistics, we found the failure intensity function (tλ. The function (tλ increases almost linearly.

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

Customer service: the key to market differentiation.

Science.gov (United States)

Stahl, D A

1997-06-01

Fierce competition in the subacute care environment makes customer service orientation essential. Four steps help to achieve quality customer service are: (1) institute core values; (2) identify your customers; (3) understand human resources; and (4) establish an efficient system.

Providing Reliability Services through Demand Response: A Prelimnary Evaluation of the Demand Response Capabilities of Alcoa Inc.

Energy Technology Data Exchange (ETDEWEB)

Starke, Michael R [ORNL; Kirby, Brendan J [ORNL; Kueck, John D [ORNL; Todd, Duane [Alcoa; Caulfield, Michael [Alcoa; Helms, Brian [Alcoa

2009-02-01

Demand response is the largest underutilized reliability resource in North America. Historic demand response programs have focused on reducing overall electricity consumption (increasing efficiency) and shaving peaks but have not typically been used for immediate reliability response. Many of these programs have been successful but demand response remains a limited resource. The Federal Energy Regulatory Commission (FERC) report, 'Assessment of Demand Response and Advanced Metering' (FERC 2006) found that only five percent of customers are on some form of demand response program. Collectively they represent an estimated 37,000 MW of response potential. These programs reduce overall energy consumption, lower green house gas emissions by allowing fossil fuel generators to operate at increased efficiency and reduce stress on the power system during periods of peak loading. As the country continues to restructure energy markets with sophisticated marginal cost models that attempt to minimize total energy costs, the ability of demand response to create meaningful shifts in the supply and demand equations is critical to creating a sustainable and balanced economic response to energy issues. Restructured energy market prices are set by the cost of the next incremental unit of energy, so that as additional generation is brought into the market, the cost for the entire market increases. The benefit of demand response is that it reduces overall demand and shifts the entire market to a lower pricing level. This can be very effective in mitigating price volatility or scarcity pricing as the power system responds to changing demand schedules, loss of large generators, or loss of transmission. As a global producer of alumina, primary aluminum, and fabricated aluminum products, Alcoa Inc., has the capability to provide demand response services through its manufacturing facilities and uniquely through its aluminum smelting facilities. For a typical aluminum smelter

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.

78 FR 69018 - Improving the Resiliency of Mobile Wireless Communications Networks; Reliability and Continuity...

Science.gov (United States)

2013-11-18

... consumers value overall network reliability and quality in selecting mobile wireless service providers, they...-125] Improving the Resiliency of Mobile Wireless Communications Networks; Reliability and Continuity... (Reliability NOI) in 2011 to ``initiate a comprehensive examination of issues regarding the reliability...

Exploring the relationship between service quality and customer satisfaction in postal financial service

Directory of Open Access Journals (Sweden)

Steven K Msosa

2015-09-01

Full Text Available Service quality and customer satisfaction are related and are important factors for the success of service providers be it in the public or the private sector. This study aims to examine the relationship between service quality and customer satisfaction in the Malawian public postal service, specifically its banking division. A cross-sectional, quantitative and descriptive study was undertaken and data was collected from 400 customers using the SERVPERF model. A non-probability sampling approach was adopted and respondents were selected using convenience sampling. Reliability of the study was tested using Cronbach alpha. Correlation tests were conducted using Spearman’s rho. The results show that all the five service quality dimensions, viz. tangibles, reliability, empathy, assurance and responsiveness, are significantly and positively correlated. There was also a significant correlation between the service quality dimensions and overall service quality, customer satisfaction and customer loyalty

A heuristic-based approach for reliability importance assessment of energy producers

International Nuclear Information System (INIS)

Akhavein, A.; Fotuhi Firuzabad, M.

2011-01-01

Reliability of energy supply is one of the most important issues of service quality. On one hand, customers usually have different expectations for service reliability and price. On the other hand, providing different level of reliability at load points is a challenge for system operators. In order to take reasonable decisions and obviate reliability implementation difficulties, market players need to know impacts of their assets on system and load-point reliabilities. One tool to specify reliability impacts of assets is the criticality or reliability importance measure by which system components can be ranked based on their effect on reliability. Conventional methods for determination of reliability importance are essentially on the basis of risk sensitivity analysis and hence, impose prohibitive calculation burden in large power systems. An approach is proposed in this paper to determine reliability importance of energy producers from perspective of consumers or distribution companies in a composite generation and transmission system. In the presented method, while avoiding immense computational burden, the energy producers are ranked based on their rating, unavailability and impact on power flows in the lines connecting to the considered load points. Study results on the IEEE reliability test system show successful application of the proposed method. - Research highlights: → Required reliability level at load points is a concern in modern power systems. → It is important to assess reliability importance of energy producers or generators. → Generators can be ranked based on their impacts on power flow to a selected area. → Ranking of generators is an efficient tool to assess their reliability importance.

Morphological differentiation of severe aplastic anaemia from hypocellular refractory cytopenia of childhood

DEFF Research Database (Denmark)

Baumann, Irith; Führer, Monika; Behrendt, Sonja

2012-01-01

To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood.......To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood....

An automated method for estimating reliability of grid systems using Bayesian networks

International Nuclear Information System (INIS)

Doguc, Ozge; Emmanuel Ramirez-Marquez, Jose

2012-01-01

Grid computing has become relevant due to its applications to large-scale resource sharing, wide-area information transfer, and multi-institutional collaborating. In general, in grid computing a service requests the use of a set of resources, available in a grid, to complete certain tasks. Although analysis tools and techniques for these types of systems have been studied, grid reliability analysis is generally computation-intensive to obtain due to the complexity of the system. Moreover, conventional reliability models have some common assumptions that cannot be applied to the grid systems. Therefore, new analytical methods are needed for effective and accurate assessment of grid reliability. This study presents a new method for estimating grid service reliability, which does not require prior knowledge about the grid system structure unlike the previous studies. Moreover, the proposed method does not rely on any assumptions about the link and node failure rates. This approach is based on a data-mining algorithm, the K2, to discover the grid system structure from raw historical system data, that allows to find minimum resource spanning trees (MRST) within the grid then, uses Bayesian networks (BN) to model the MRST and estimate grid service reliability.

Gender differentials in readiness and use of mHealth services in a rural area of Bangladesh.

Science.gov (United States)

Khatun, Fatema; Heywood, Anita E; Hanifi, Syed Manzoor Ahmed; Rahman, M Shafiqur; Ray, Pradeep K; Liaw, Siaw-Teng; Bhuiya, Abbas

2017-08-18

Traditional gender roles result in women lagging behind men in the use of modern technologies, especially in developing countries. Although there is rapid uptake of mobile phone use in Bangladesh, investigation of gender differences in the ownership, access and use of mobile phones in general and mHealth in particular has been limited. This paper presents gender differentials in the ownership of mobile phones and knowledge of available mHealth services in a rural area of Bangladesh. We interviewed 4915 randomly selected respondents aged 18 years and above. Associations between gender and knowledge of available mHealth services, use of existing mHealth services and intentions to use mHealth services in the future were examined by multivariate logistic regression analysis, controlling for the effect of categorised covariates. Of the 4915 respondents to the survey, 61.8% of men (1213/1964) and 34.4% of women (1015/2951) owned a mobile phone. For men, mobile phone ownership was highest among those aged 18-29 years (n = 663, 76.3%), and for women among those aged 30-39 years (n = 825, 44.7%). A higher proportion of men owned phones compared to women, irrespective of socioeconomic status (SES) as indicated by asset index (p mHealth services was lower among women than men; however, intention to use mHealth services in the future was high for both genders, irrespective of age, education and socioeconomic status. Compared to men, women are less likely to own a mobile phone and less aware of available mHealth services, despite high intention to use mHealth among both genders. To optimise the use of mHealth services and to achieve equity of use, uptake strategies should target women, with a focus on the poorer and less educated groups.

The Effects of Brand Experiences on Quality, Satisfaction and Loyalty: An Empirical Study in the Telecommunications Multiple-play Service Market

Directory of Open Access Journals (Sweden)

António Carrizo Moreira

2017-03-01

Full Text Available This article seeks to add to the body of knowledge on the role played by brand experience and its relationship with satisfaction, trust and service quality in the development of loyalty. Structural Equation Modelling (sem is used to analyze 690 telecommunications multiple-play users in the Portuguese telecommunications market. Our conclusions show that brand experiences can be used to generate loyalty, trust and quality perceptions; although satisfaction was confirmed to be the main loyalty predictor, service quality has an important indirect effect. In order to build customer loyalty, marketers must manage brand experiences, service quality, satisfaction and trust. Brand experiences can be explored as a way to differentiate services, to change customers’ perceptions toward a brand and, ultimately, lead to customer retention. Furthermore, providing reliable services is of the utmost importance for service providers.

Comparison of two methods for customer differentiation

NARCIS (Netherlands)

A.F. Gabor (Adriana); Y. Guang (Yang); S. Axsäter (Sven)

2014-01-01

textabstractIn response to customer specific time guarantee requirements, service providers can offer differentiated ser- vices. However, conventional customer differentiation methods often lead to high holding costs and may have some practical drawbacks. We compare two customer differentiation

[Validity and reliability of the Culture of Quality Health Services questionnaire in Mexico].

Science.gov (United States)

Herrera-Kiengelher, L; Zepeda-Zaragoza, J; Austria-Corrales, F; Vázquez-Zarate, V M

2013-01-01

Patient Safety is a major public health problem worldwide and is responsibility of all those involved in health care. Establishing a Safety Culture has proved to be a factor that favors the integration of work teams, communication and construction of clear procedures in various organizations. Promote a culture of safety depends on several factors, such as organization, work unit and staff. Objective assessment of these factors will help to identify areas for improvement and establish strategic lines of action. [corrected] To adapt, validate and calibrate the questionnaire Culture of Quality in Health Services (CQHS) in Mexican population. A cross with a stratified representative sample of 522 health workers. The questionnaire was translated and adapted from Singer's. Content was validated by experts, internal consistency, confirmatory factorial validity and item calibration with Samejima's Graded Response Model. Convergent and divergent construct validity was confirmed from the CQHS, item calibration showed that the questionnaire is able to discriminate between patients and represent different levels of the hypothesized dimensions with greater accuracy and lower standard error. The CQHS is a valid and reliable instrument to assess patient safety culture in hospitals in Mexico. Copyright © 2013 SECA. Published by Elsevier Espana. All rights reserved.

Assessment of physical server reliability in multi cloud computing system

Science.gov (United States)

Kalyani, B. J. D.; Rao, Kolasani Ramchand H.

2018-04-01

Business organizations nowadays functioning with more than one cloud provider. By spreading cloud deployment across multiple service providers, it creates space for competitive prices that minimize the burden on enterprises spending budget. To assess the software reliability of multi cloud application layered software reliability assessment paradigm is considered with three levels of abstractions application layer, virtualization layer, and server layer. The reliability of each layer is assessed separately and is combined to get the reliability of multi-cloud computing application. In this paper, we focused on how to assess the reliability of server layer with required algorithms and explore the steps in the assessment of server reliability.

Optimal Service Distribution in WSN Service System Subject to Data Security Constraints

Science.gov (United States)

Wu, Zhao; Xiong, Naixue; Huang, Yannong; Gu, Qiong

2014-01-01

Services composition technology provides a flexible approach to building Wireless Sensor Network (WSN) Service Applications (WSA) in a service oriented tasking system for WSN. Maintaining the data security of WSA is one of the most important goals in sensor network research. In this paper, we consider a WSN service oriented tasking system in which the WSN Services Broker (WSB), as the resource management center, can map the service request from user into a set of atom-services (AS) and send them to some independent sensor nodes (SN) for parallel execution. The distribution of ASs among these SNs affects the data security as well as the reliability and performance of WSA because these SNs can be of different and independent specifications. By the optimal service partition into the ASs and their distribution among SNs, the WSB can provide the maximum possible service reliability and/or expected performance subject to data security constraints. This paper proposes an algorithm of optimal service partition and distribution based on the universal generating function (UGF) and the genetic algorithm (GA) approach. The experimental analysis is presented to demonstrate the feasibility of the suggested algorithm. PMID:25093346

Screening for Partner Violence Among Family Mediation Clients: Differentiating Types of Abuse.

Science.gov (United States)

Cleak, Helen; Schofield, Margot J; Axelsen, Lauren; Bickerdike, Andrew

2018-04-01

Family mediation is mandated in Australia for couples in dispute over separation and parenting as a first step in dispute resolution, except where there is a history of intimate partner violence. However, validation of effective well-differentiated partner violence screening instruments suitable for mediation settings is at an early phase of development. This study contributes to calls for better violence screening instruments in the mediation context to detect a differentiated range of abusive behaviors by examining the reliability and validity of both established scales, and newly developed scales that measured intimate partner violence by partner and by self. The study also aimed to examine relationships between types of abuse, and between gender and types of abuse. A third aim was to examine associations between types of abuse and other relationship indicators such as acrimony and parenting alliance. The data reported here are part of a larger mixed method, naturalistic longitudinal study of clients attending nine family mediation centers in Victoria, Australia. The current analyses on baseline cross-sectional screening data confirmed the reliability of three subscales of the Conflict Tactics Scale (CTS2), and the reliability and validity of three new scales measuring intimidation, controlling and jealous behavior, and financial control. Most clients disclosed a history of at least one type of violence by partner: 95% reported psychological aggression, 72% controlling and jealous behavior, 50% financial control, and 35% physical assault. Higher rates of abuse perpetration were reported by partner versus by self, and gender differences were identified. There were strong associations between certain patterns of psychologically abusive behavior and both acrimony and parenting alliance. The implications for family mediation services and future research are discussed.

The influence of frequency and reliability of in-service inspection on reactor pressure vessel disruptive failure probability

International Nuclear Information System (INIS)

Jordan, G.M.

1977-01-01

A simple probabilistic methodology is used to investigate the benefit, in terms of reduction of disruptive failure probability, which comes from the application of periodic In Service Inspection (ISI) to nuclear pressure vessels. The analysis indicates the strong interaction between inspection benefit and the intrinsic quality of the structure. In order to quantify the inspection benefit, assumptions are made which allow the quality to be characterized in terms of the parameters governing a Log Normal distribution of time-to-failure. Using these assumptions, it is shown that the overall benefit of ISI is unlikely to exceed an order of magnitude in terms of reduction of disruptive failure probability. The method is extended to evaluate the effect of the periodicity and reliability of the inspection process itself. (author)

Design and Analysis of Transport Protocols for Reliable High-Speed Communications

NARCIS (Netherlands)

Oláh, A.

1997-01-01

The design and analysis of transport protocols for reliable communications constitutes the topic of this dissertation. These transport protocols guarantee the sequenced and complete delivery of user data over networks which may lose, duplicate and reorder packets. Reliable transport services are

Impact of inservice inspection on the reliability of nuclear piping

International Nuclear Information System (INIS)

Woo, H.H.

1983-12-01

The reliability of nuclear piping is a function of piping quality as fabricated, service loadings and environments, plus programs of continuing inspection during operation. This report presents the results of a study of the impact of inservice inspection (ISI) programs on the reliability of specific nuclear piping systems that have actually failed in service. Two major factors are considered in the ISI programs: one is the capability of detecting flaws; the other is the frequency of performing ISI. A probabilistic fracture mechanics model issued to estimate the reliability of two nuclear piping lines over the plant life as functions of the ISI programs. Examples chosen for the study are the PWR feedwater steam generator nozzle cracking incident and the BWR recirculation reactor vessel nozzle safe-end cracking incident

Adjoint sensitivity analysis of dynamic reliability models based on Markov chains - II: Application to IFMIF reliability assessment

Energy Technology Data Exchange (ETDEWEB)

Cacuci, D. G. [Commiss Energy Atom, Direct Energy Nucl, Saclay, (France); Cacuci, D. G.; Balan, I. [Univ Karlsruhe, Inst Nucl Technol and Reactor Safetly, Karlsruhe, (Germany); Ionescu-Bujor, M. [Forschungszentrum Karlsruhe, Fus Program, D-76021 Karlsruhe, (Germany)

2008-07-01

In Part II of this work, the adjoint sensitivity analysis procedure developed in Part I is applied to perform sensitivity analysis of several dynamic reliability models of systems of increasing complexity, culminating with the consideration of the International Fusion Materials Irradiation Facility (IFMIF) accelerator system. Section II presents the main steps of a procedure for the automated generation of Markov chains for reliability analysis, including the abstraction of the physical system, construction of the Markov chain, and the generation and solution of the ensuing set of differential equations; all of these steps have been implemented in a stand-alone computer code system called QUEFT/MARKOMAG-S/MCADJSEN. This code system has been applied to sensitivity analysis of dynamic reliability measures for a paradigm '2-out-of-3' system comprising five components and also to a comprehensive dynamic reliability analysis of the IFMIF accelerator system facilities for the average availability and, respectively, the system's availability at the final mission time. The QUEFT/MARKOMAG-S/MCADJSEN has been used to efficiently compute sensitivities to 186 failure and repair rates characterizing components and subsystems of the first-level fault tree of the IFMIF accelerator system. (authors)

Adjoint sensitivity analysis of dynamic reliability models based on Markov chains - II: Application to IFMIF reliability assessment

International Nuclear Information System (INIS)

Cacuci, D. G.; Cacuci, D. G.; Balan, I.; Ionescu-Bujor, M.

2008-01-01

In Part II of this work, the adjoint sensitivity analysis procedure developed in Part I is applied to perform sensitivity analysis of several dynamic reliability models of systems of increasing complexity, culminating with the consideration of the International Fusion Materials Irradiation Facility (IFMIF) accelerator system. Section II presents the main steps of a procedure for the automated generation of Markov chains for reliability analysis, including the abstraction of the physical system, construction of the Markov chain, and the generation and solution of the ensuing set of differential equations; all of these steps have been implemented in a stand-alone computer code system called QUEFT/MARKOMAG-S/MCADJSEN. This code system has been applied to sensitivity analysis of dynamic reliability measures for a paradigm '2-out-of-3' system comprising five components and also to a comprehensive dynamic reliability analysis of the IFMIF accelerator system facilities for the average availability and, respectively, the system's availability at the final mission time. The QUEFT/MARKOMAG-S/MCADJSEN has been used to efficiently compute sensitivities to 186 failure and repair rates characterizing components and subsystems of the first-level fault tree of the IFMIF accelerator system. (authors)

Differential reliability : probabilistic engineering applied to wood members in bending-tension

Science.gov (United States)

Stanley K. Suddarth; Frank E. Woeste; William L. Galligan

1978-01-01

Reliability analysis is a mathematical technique for appraising the design and materials of engineered structures to provide a quantitative estimate of probability of failure. Two or more cases which are similar in all respects but one may be analyzed by this method; the contrast between the probabilities of failure for these cases allows strong analytical focus on the...

SEQUenCE: a service user-centred quality of care instrument for mental health services.

Science.gov (United States)

Hester, Lorraine; O'Doherty, Lorna Jane; Schnittger, Rebecca; Skelly, Niamh; O'Donnell, Muireann; Butterly, Lisa; Browne, Robert; Frorath, Charlotte; Morgan, Craig; McLoughlin, Declan M; Fearon, Paul

2015-08-01

To develop a quality of care instrument that is grounded in the service user perspective and validate it in a mental health service. The instrument (SEQUenCE (SErvice user QUality of CarE)) was developed through analysis of focus group data and clinical practice guidelines, and refined through field-testing and psychometric analyses. All participants were attending an independent mental health service in Ireland. Participants had a diagnosis of bipolar affective disorder (BPAD) or a psychotic disorder. Twenty-nine service users participated in six focus group interviews. Seventy-one service users participated in field-testing: 10 judged the face validity of an initial 61-item instrument; 28 completed a revised 52-item instrument from which 12 items were removed following test-retest and convergent validity analyses; 33 completed the resulting 40-item instrument. Test-retest reliability, internal consistency and convergent validity of the instrument. The final instrument showed acceptable test-retest reliability at 5-7 days (r = 0.65; P Service Satisfaction Scale (r = 0.84, P internal consistency (Cronbach's alpha = 0.87). SEQUenCE is a valid, reliable scale that is grounded in the service user perspective and suitable for routine use. It may serve as a useful tool in individual care planning, service evaluation and research. The instrument was developed and validated with service users with a diagnosis of either BPAD or a psychotic disorder; it does not yet have established external validity for other diagnostic groups. © The Author 2015. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

Choice experiment study on the willingness to pay to improve electricity services

Energy Technology Data Exchange (ETDEWEB)

Abdullah, Sabah [Department of Economics, Claverton Down, University of Bath, Bath BA2 7AY (United Kingdom); Department of Economic Analysis and Institute of Public Economics, University of the Basque Country Avda. Lehendakari Aguirre 81, 48015 Bilbao (Spain); Mariel, Petr [Department of Applied Economics III (Econometrics and Statistics), University of the Basque Country Avda. Lehendakari Aguirre 83, E48015 Bilbao (Spain)

2010-08-15

Modern forms of energy are an important vehicle towards poverty alleviation in rural areas of developing countries. Most developing countries' households rely heavily on wood fuel which impacts on their health and socio-economic status. To ease such a dependency, other modern forms of energy, namely electricity, need to be provided. However, the quality of the electricity service, namely reliability, is an important factor in reducing this dependency. This paper discusses a choice experiment valuation study conducted among electrified rural households located in Kisumu, Kenya, in which the willingness to pay (WTP) to avoid power outages or blackouts was estimated. A mixed logit estimation was applied to identify the various socio-economic and demographic characteristics which determine preferences in reducing power outages among a household's users. In conclusion, several of the socio-economic and demographic characteristics outlined in this paper were identified and can assist service differentiation to accommodate the diverse households' preferences towards the improvement of the electricity service. (author)

Choice experiment study on the willingness to pay to improve electricity services

International Nuclear Information System (INIS)

Abdullah, Sabah; Mariel, Petr

2010-01-01

Modern forms of energy are an important vehicle towards poverty alleviation in rural areas of developing countries. Most developing countries' households rely heavily on wood fuel which impacts on their health and socio-economic status. To ease such a dependency, other modern forms of energy, namely electricity, need to be provided. However, the quality of the electricity service, namely reliability, is an important factor in reducing this dependency. This paper discusses a choice experiment valuation study conducted among electrified rural households located in Kisumu, Kenya, in which the willingness to pay (WTP) to avoid power outages or blackouts was estimated. A mixed logit estimation was applied to identify the various socio-economic and demographic characteristics which determine preferences in reducing power outages among a household's users. In conclusion, several of the socio-economic and demographic characteristics outlined in this paper were identified and can assist service differentiation to accommodate the diverse households' preferences towards the improvement of the electricity service.

Reliability and safety of nuclear power stations

International Nuclear Information System (INIS)

Stepanek, S.

1979-01-01

The main problems are briefly discussed associated with the assessment of the safety and reliability of reactor pressure vessels. Two approaches are being applied to the assessment: one is based on the crack arrest temperature, the other on the determination of conditions corresponding to brittle fracture formation and on the determination of the critical defect size. The importance is stressed of continuous in-service inspection which may increase the factor of reliability by up to 10 4 times. (Z.M.)

Reliability assessment of creep rupture life for Gr. 91 steel

International Nuclear Information System (INIS)

Kim, Woo-Gon; Park, Jae-Young; Kim, Seon-Jin; Jang, Jinsung

2013-01-01

Highlights: • Statistical analysis of a number of creep rupture data based on Z parameter. • Determination of the constant C in LM parameter and long-term creep life prediction. • Generation of random variables for Z s and Z cr by Monte-Carlo simulation in a SCRI model. • Examples for design application were reasonably drawn from the viewpoints of reliability. - Abstract: This paper presents reliability assessment of the long-term creep life of Gr. 91 steel, which is a major structural material for high temperature structural components of Generation-IV reactor systems. A number of creep rupture data for Gr. 91 steel were collected through literature surveys, and the long-term creep life was predicted by Larson–Miller parameter. A “Z parameter” method was used to describe the magnitude of the deviation of the creep rupture data to a master curve. A “Service Condition-creep Rupture property Interference (SCRI) model” based on the Z parameter was used to simultaneously consider the scattering of the creep rupture data of materials and the fluctuations of service conditions in reliability assessment. A statistical analysis of the creep rupture data was conducted by the Z parameter. To carry out the SCRI model, a number of random variables for Z s describing service conditions and Z cr describing the dispersion of the creep rupture data were generated using a Monte-Carlo simulation technique. As examples for application, the creep rupture life under a certain service conditions of Gr. 91 steel was reasonably drawn from the viewpoints of reliability

Differential topology

CERN Document Server

Margalef-Roig, J

1992-01-01

...there are reasons enough to warrant a coherent treatment of the main body of differential topology in the realm of Banach manifolds, which is at the same time correct and complete. This book fills the gap: whenever possible the manifolds treated are Banach manifolds with corners. Corners add to the complications and the authors have carefully fathomed the validity of all main results at corners. Even in finite dimensions some results at corners are more complete and better thought out here than elsewhere in the literature. The proofs are correct and with all details. I see this book as a reliable monograph of a well-defined subject; the possibility to fall back to it adds to the feeling of security when climbing in the more dangerous realms of infinite dimensional differential geometry. Peter W. Michor

Differential Dynamic Evolutionary Model of Emergency Financial Service Supply Chain in Natural Disaster Risk Management

Directory of Open Access Journals (Sweden)

Shujian Ma

2016-01-01

Full Text Available A government-market-public partnership (GMPP could be a feasible arrangement for providing insurance coverage for natural disaster. Firstly, we put forward GMPP management mode. Secondly, the emergency financial service supply chain for natural disaster risk is built from the view of supply chain. Finally, the objective of this paper is to obtain insights into the cooperative and competitive relationship in GMPP system. We establish the cooperative and competitive differential dynamic evolutionary models and prove the existence of equilibrium solutions in order to solve the coordination problems. In conclusion, the equilibrium solutions can be achieved among the insurers, the operating governments, and the public.

System Reliability Evaluation of Data Transmission in Commercial Banks with Multiple Branches

Directory of Open Access Journals (Sweden)

Yi-Kuei Lin

2014-01-01

Full Text Available The main purpose of this paper is to assess the system reliability of electronic transaction data transmissions made by commercial banks in terms of stochastic flow network. System reliability is defined as the probability of demand satisfaction and it can be used to measure quality of service. In this paper, we study the system reliability of data transmission from the headquarters of a commercial bank to its multiple branches. The network structure of the bank and the probability of successful data transmission are obtained through the collection of real data. The system reliability, calculated using the minimal path method and the recursive sum of disjoint products algorithm, provides banking managers with a view to comprehend the current state of the entire system. Besides, the system reliability can be used not only as a measurement of quality of service, but also an improvement reference of the system by adopting sensitivity analysis.

Retail service quality as a base in purchasing decision

Directory of Open Access Journals (Sweden)

Sokolov-Mladenović Svetlana

2015-01-01

Full Text Available Retail is a service activity, and services are something that makes the retail companies differ from production companies. Retailers are trying to differentiate the 'package' offer, build customer loyalty and make their position through the provision of high service quality. In addition, the services provided can be varied, such as exterior and interior design of retail stores, preparation of goods for sale, appearance and behavior of sales personnel, culture of communication with customers, and services provided after the sales process. Consumers require the service quality when making purchasing decision. For retail companies and retail stores it is important to continuously monitor the level of service quality. In order to measure the service quality, the method that found its application in the theory and practice is SERVQUAL. This model was created as a combination of theoretical and practical research and it looks at the quality of service as the content of the following dimensions: tangibles, reliability, sensitivity, security and empathy. As such, it is a function of the difference between perceptions and expectations (Q = P-E and is widely accepted to measure the service quality in traditional retail stores, public sector, higher education, real estate, hospitals, courts and so on. In addition, this model is widely used to measure service quality in e-retailing, e-banking, e-selling of travel packages and other services provided by electronic means. The main assumption is that services are a key factor in making purchasing decision. The aim of this paper is to, through theoretical and practical research with special emphasis on SERVQUAL method, test the initial hypothesis and recognize the level of service quality in retail chains in Southeast Serbia.

Service Quality and Non-Muslim Satisfaction Using Sharia Bank Products and Services

Directory of Open Access Journals (Sweden)

Nova Ch Mamuaya

2018-01-01

Full Text Available Some studies show that religious belief does not take effect affecting consumer using sharia bank products and services. This research has implemented six dimensions of Othman and Owen which modified five dimensions of Parasuraman with adding compliance dimension. The six dimensions of Othman & Owen are known as CARTER (compliance, assurance, reliability, tangible, empathy, and responsiveness. The research purpose is to analyze compliance, assurance, reliability, tangible, empathy, and responsiveness effect on non-Muslim customer satisfaction on sharia bank products and services at Manado Sulawesi Utara partially or simultaneously. The data was gathered with questionnaire instruments of 70 respondents, measured with five Likert scale five dots. The research result shows compliance, assurance, reliability, tangible, empathy, and responsiveness has significant effect on customer satisfaction. Responsive has most strong effect and compliance is the weakest.

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

Ultra-Reliable Communication in 5G Wireless Systems

DEFF Research Database (Denmark)

Popovski, Petar

2014-01-01

—Wireless 5G systems will not only be “4G, but faster”. One of the novel features discussed in relation to 5G is Ultra-Reliable Communication (URC), an operation mode not present in today’s wireless systems. URC refers to provision of certain level of communication service almost 100 % of the time....... Example URC applications include reliable cloud connectivity, critical connections for industrial automation and reliable wireless coordination among vehicles. This paper puts forward a systematic view on URC in 5G wireless systems. It starts by analyzing the fundamental mechanisms that constitute......-term URC (URC-S). The second dimension is represented by the type of reliability impairment that can affect the communication reliability in a given scenario. The main objective of this paper is to create the context for defining and solving the new engineering problems posed by URC in 5G....

AN ANALYTICAL FRAMEWORK FOR ASSESSING RELIABLE NUCLEAR FUEL SERVICE APPROACHES: ECONOMIC AND NON-PROLIFERATION MERITS OF NUCLEAR FUEL LEASING

International Nuclear Information System (INIS)

Kreyling, Sean J.; Brothers, Alan J.; Short, Steven M.; Phillips, Jon R.; Weimar, Mark R.

2010-01-01

The goal of international nuclear policy since the dawn of nuclear power has been the peaceful expansion of nuclear energy while controlling the spread of enrichment and reprocessing technology. Numerous initiatives undertaken in the intervening decades to develop international agreements on providing nuclear fuel supply assurances, or reliable nuclear fuel services (RNFS) attempted to control the spread of sensitive nuclear materials and technology. In order to inform the international debate and the development of government policy, PNNL has been developing an analytical framework to holistically evaluate the economics and non-proliferation merits of alternative approaches to managing the nuclear fuel cycle (i.e., cradle-to-grave). This paper provides an overview of the analytical framework and discusses preliminary results of an economic assessment of one RNFS approach: full-service nuclear fuel leasing. The specific focus of this paper is the metrics under development to systematically evaluate the non-proliferation merits of fuel-cycle management alternatives. Also discussed is the utility of an integrated assessment of the economics and non-proliferation merits of nuclear fuel leasing.

Upgrading elastomer seals for nuclear service

Energy Technology Data Exchange (ETDEWEB)

Wittich, K C; Wensel, R; LaRose, R; Kuran, S

1995-06-01

Pumps, valves and instruments in nuclear plants have historically contained whatever elastomer each equipment supplier traditionally used for corresponding non-nuclear service. The proliferation of elastomer compounds, and their sometimes uncertain reliability, is now being reduced by upgrading and standardizing on a handful of compounds that have each been verified to be high performers for their class of service conditions. The objective is to make cost-effective improvements in the reliability and integrity of equipment in Canadian-designed nuclear plants. The effort focuses on elastomer seals and includes: understanding sealing fundamentals, developing relevant data for superior compounds for each service, and improving quality assurance methods, including handling and inspection guidelines. In practice, discussions with plant personnel and review of plant records are the first step. Two severe-service examples are given where these needs have been met by the following progression of activities: inspecting and laboratory testing of seals removed from service, preliminary and qualification testing of improvements, introduction into service, and monitoring the upgraded seals during phase-in periods. Large gains in reliability and integrity have been demonstrated for simulated normal and accident service conditions of heat, radiation and other deteriorative influences. Significant savings in maintenance costs are also projected. (author). 2 refs., 6 figs.

Upgrading elastomer seals for nuclear service

International Nuclear Information System (INIS)

Wittich, K.C.; Wensel, R.; LaRose, R.; Kuran, S.

1995-06-01

Pumps, valves and instruments in nuclear plants have historically contained whatever elastomer each equipment supplier traditionally used for corresponding non-nuclear service. The proliferation of elastomer compounds, and their sometimes uncertain reliability, is now being reduced by upgrading and standardizing on a handful of compounds that have each been verified to be high performers for their class of service conditions. The objective is to make cost-effective improvements in the reliability and integrity of equipment in Canadian-designed nuclear plants. The effort focuses on elastomer seals and includes: understanding sealing fundamentals, developing relevant data for superior compounds for each service, and improving quality assurance methods, including handling and inspection guidelines. In practice, discussions with plant personnel and review of plant records are the first step. Two severe-service examples are given where these needs have been met by the following progression of activities: inspecting and laboratory testing of seals removed from service, preliminary and qualification testing of improvements, introduction into service, and monitoring the upgraded seals during phase-in periods. Large gains in reliability and integrity have been demonstrated for simulated normal and accident service conditions of heat, radiation and other deteriorative influences. Significant savings in maintenance costs are also projected. (author). 2 refs., 6 figs

Upgrading elastomer seals for nuclear service

International Nuclear Information System (INIS)

Wittich, K.C.; Wensel, R.; Larose, R.; Kuran, S.

1998-01-01

Pumps, valves and instruments in nuclear plants have historically contained whatever elastomer each equipment supplier traditionally used for corresponding non-nuclear service. The proliferation of elastomer compounds, and their sometimes uncertain reliability, is now being reduced by upgrading and standardizing on a handful of compounds that have each been verified to be high performers for their class of service conditions. The objective is to make cost-effective improvements in the reliability and integrity of equipment in Canadian-designed nuclear plants. The effort focuses on elastomer seals and includes: understanding sealing fundamentals, developing relevant data for superior compounds for each service, and improving quality assurance methods, including handling and inspection guidelines. In practice, discussion with plant personnel and review of plant records are the first step. Two severe-service examples are given where these needs have been met by the following progression of activities: inspecting and laboratory testing of seals removed from service, preliminary and qualification testing of improvements, introduction into service, and monitoring the upgraded seals during phase-in periods. Large gains in reliability and integrity have been demonstrated for simulated normal and accident service conditions of heat, radiation and other deteriorative influences. Significant savings in maintenance costs are also projected. (author)

Differentiated Instruction at Work. Reinforcing the Art of Classroom Observation through the Creation of a Checklist for Beginning and Pre-Service Teachers

Science.gov (United States)

Subban, Pearl; Round, Penny

2015-01-01

Professional experience is viewed as integral to shaping philosophy and acquiring skills in the area of classroom teaching. Classrooms are complex places, with educators implementing differentiated strategies to cater for student diversity. Pre-service teachers who observe these lessons often miss the intuitive practices, as there is much to…

Preliminary Analysis of LORAN-C System Reliability for Civil Aviation.

Science.gov (United States)

1981-09-01

overviev of the analysis technique. Section 3 describes the computerized LORAN-C coverage model which is used extensively in the reliability analysis...Xth Plenary Assembly, Geneva, 1963, published by International Telecomunications Union. S. Braff, R., Computer program to calculate a Karkov Chain Reliability Model, unpublished york, MITRE Corporation. A-1 I.° , 44J Ili *Y 0E 00 ...F i8 1110 Prelim inary Analysis of Program Engineering & LORAN’C System ReliabilityMaintenance Service i ~Washington. D.C.

Pharmacy Service Orientation: a measure of organizational culture in pharmacy practice sites.

Science.gov (United States)

Clark, Bartholomew E; Mount, Jeanine K

2006-03-01

The importance of organizational culture in shaping everyday organizational life is well accepted, but little work has focused on organizational culture in pharmacy. Examining new pharmacists' experiences at various practice sites may help us to understand how these shape their professional ethos and practice habits. (1) Present development and assessment of the Pharmacy Service Orientation (PSO) measure, a tool for assessing pharmacists' impressions of pharmacy practice sites. (2) Use data gathered from a sample of new pharmacists to explore potential predictors of PSO, including type of practice site, type of pharmacy work experience, and type of pharmacy degree. Mail survey of randomly selected class of 1999 pharmacy graduates within 3 months of graduation (response rate: 259 of 1,850; 14%), each of whom reported on up to 6 different pharmacy practice sites for a total of 1,192 pharmacy observations. Pharmacy Service Orientation is scored on a 1-10 semantic differential scale and reliability was assessed using Cronbach's alpha. Predictors of PSO were explored using t test and ordinary least squares regression procedures. Reliability of the PSO across all observations was 0.86. When divided according to recency of experience and type of experience, reliabilities ranged from 0.78 to 0.87. Analysis of potential predictors of PSO showed that non-corporate-community sites had significantly greater pharmaceutical care-oriented cultures (mean PSOs of 7.42 and 5.13, respectively; PService Orientation is a reliable measure. Statistically significant differences in PSO comparisons by degree and by experience type are explained by significant differences between the PSOs of corporate-community and non-corporate-community sites.

Improved reliability, maintainability and safety through elastomer upgrading

International Nuclear Information System (INIS)

Wensel, R.; Wittich, K.C.

1995-01-01

Equipment in nuclear plants has historically contained whatever elastomer each component supplier traditionally used for corresponding non-nuclear service. The resulting proliferation of elastomer compounds, many of which are far from optimal for the service conditions (e.g., pressure, temperature, radiation, etc.), has multiplied the costs to provide station reliability, maintainability and safety. Cost-effective improvements are being achieved in CANDU plants by upgrading and standardizing on a handful of high performing elastomer compounds. These upgraded materials offer significant gains in service life over the materials they replace (often by factors of 2 or more). This rationalization of elastomer compounds also facilitates the EQ process for safety-related equipment. Detailed test data on aging is currently being generated for these specific elastomers, encompassing the conditions and media (air, water, oil) common in CANDU service. Two key elements characterize this testing. First, each result is specific to the compound used in the test, and second, it is specific to the tested failure mode (e.g., compression set, extrusion, fracture, etc.). Having fewer, but more thoroughly tested compounds, avoids the penalty (associated with poorly characterized materials) of having to replace parts prematurely because of conservatism, while maintaining safe, reliable service. This paper provides an overview of this approach covering: the benefits of compound rationalization; and the how and why of establishing relevant failure criteria; appropriate quality assurance to maintain EQ; procurement, storage and handling guidelines; and monitoring and predicting in-service degradation. (author)

Collaborative Business Services Provision

NARCIS (Netherlands)

Camarinha-Matos, L.M.; Afsarmanesh, H.; Oliveira, A.I.; Ferrada, F.; Hammoudi, S.; Maciaszek, L.A.; Cordeiro, J.; Dietz, J.L.G.

2013-01-01

The association of services to manufactured products, leading to service-enhanced products, is an important mechanism for value creation and differentiation. This is particularly relevant in the case of complex, highly customized and long-life products. Suitable servicing in this context typically

Transmission embedded cost allocation methodology with consideration of system reliability

International Nuclear Information System (INIS)

Hur, D.; Park, J.-K.; Yoo, C.-I.; Kim, B.H.

2004-01-01

In a vertically integrated utility industry, the cost of reliability, as a separate service, has not received much rigorous analysis. However, as a cornerstone of restructuring the industry, the transmission service pricing must change to be consistent with, and supportive of, competitive wholesale electricity markets. This paper focuses on the equitable allocation of transmission network embedded costs including the transmission reliability cost based on the contributions of each generator to branch flows under normal conditions as well as the line outage impact factor under a variety of load levels. A numerical example on a six-bus system is given to illustrate the applications of the proposed methodology. (author)

Understanding health-related quality of life in caregivers of civilians and service members/veterans with traumatic brain injury: Establishing the reliability and validity of PROMIS Fatigue and Sleep Disturbance item banks.

Science.gov (United States)

Carlozzi, Noelle E; Ianni, Phillip A; Tulsky, David S; Brickell, Tracey A; Lange, Rael T; French, Louis M; Cella, David; Kallen, Michael A; Miner, Jennifer A; Kratz, Anna L

2018-06-19

To examine the reliability and validity of Patient Reported Outcomes Measurement Information System (PROMIS) measures of sleep disturbance and fatigue in TBI caregivers and to determine the severity of fatigue and sleep disturbance in these caregivers. Cross-sectional survey data collected through an online data capture platform. Four rehabilitation hospitals and Walter Reed National Military Medical Center. Caregivers (N=560) of civilians (n=344) and service member/veterans (n=216) with TBI. Not Applicable MAIN OUTCOME MEASURES: PROMIS sleep and fatigue measures administered as both computerized adaptive tests (CATs) and 4-item short forms (SFs). For both samples, floor and ceiling effects for the PROMIS measures were low (internal consistency was very good (all alphas ≥0.80), and test-retest reliability was acceptable (all r≥0.70 except for the fatigue CAT in the service member/veteran sample r=0.63). Convergent validity was supported by moderate correlations between the PROMIS and related measures. Discriminant validity was supported by low correlations between PROMIS measures and measures of dissimilar constructs. PROMIS scores indicated significantly worse sleep and fatigue for those caring for someone with high levels versus low levels of impairment. Findings support the reliability and validity of the PROMIS CAT and SF measures of sleep disturbance and fatigue in caregivers of civilians and service members/veterans with TBI. Copyright © 2018. Published by Elsevier Inc.

Service Oriented Architecture for High Level Applications

International Nuclear Information System (INIS)

Chu, P.

2012-01-01

Standalone high level applications often suffer from poor performance and reliability due to lengthy initialization, heavy computation and rapid graphical update. Service-oriented architecture (SOA) is trying to separate the initialization and computation from applications and to distribute such work to various service providers. Heavy computation such as beam tracking will be done periodically on a dedicated server and data will be available to client applications at all time. Industrial standard service architecture can help to improve the performance, reliability and maintainability of the service. Robustness will also be improved by reducing the complexity of individual client applications.

Delta neutrophil index: A reliable marker to differentiate perforated appendicitis from non-perforated appendicitis in the elderly.

Science.gov (United States)

Shin, Dong Hyuk; Cho, Young Suk; Kim, Yoon Sung; Ahn, Hee Cheol; Oh, Young Taeck; Park, Sang O; Won, Moo-Ho; Cho, Jun Hwi; Kim, Young Myeong; Seo, Jeong Yeol; Lee, Young Hwan

2018-01-01

Delta neutrophil index (DNI) is a new inflammatory marker and the present study aimed to evaluate the predictive value of the DNI for the presence of a perforation in elderly with acute appendicitis. This retrospective observational study was conducted on 108 consecutive elderly patients (≥65 years old) with acute appendicitis treated over a 24-month period. Sixty-nine of the 108 patients (median, IQR: 72, 67-77 years) were allocated to the perforated appendicitis group (63.9%) and 39 to the non-perforated appendicitis group (36.1%). WBC, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and DNI were significantly higher in the perforated group. In multiple logistic regression analyses, initial DNI was the only independent marker that can significantly predict the presence of perforation in multiple regression [odds ratio 9.38, 95% confidence interval (2.51-35.00), P=.001]. Receiver operator characteristic curve analysis showed that DNI is a good predictor for the presence of appendiceal perforation at an optimal cut-off for DNI being 1.4% (sensitivity 67.7%, specificity 90.0%, AUC 0.807). Clinicians can reliably differentiate acute perforated appendicitis from non-perforated appendicitis by DNI level of 1.4 or more in elderly patients. © 2017 Wiley Periodicals, Inc.

Versatile routing and services with BGP understanding and implementing BGP in SR-OS

CERN Document Server

Alcatel-Lucent

2014-01-01

Design a robust BGP control plane within a secure, scalable network for smoother services A robust Border Gateway Protocol setup is vital to ensuring reliable connectivity, an essential capability for any organization. The Internet has become a necessary, always-on service in homes and businesses, and BGP is the protocol that keeps communication flowing. But BGP also has become crucial to delivery of intra-domain business services. But the network is only as reliable as BGP, so service enablement depends upon making BGP more stable, reliable, and service-rich. Alcatel-Lucent Service Router Ope

A physical review on power system reliability factors

International Nuclear Information System (INIS)

Navid, Taghizadegan; Ahmad Reza, Zentabchi; Mohammad Ali, Tavakoli; Nader, Samsunchi; Mohammad Ali, Tavakoli

2005-01-01

Full text : Planning and design engineers and management must necessarily take into consideration the funds available, the requirements of regulatory agencies and other restrictions that may be imposed, as well as availability of equipment and supplies. A well-designed electrical power system strikes a reasonable between reliability and cost. A prime responsibility of power system operators is to operate their systems in such a way that will provide the maximum reliability of service possible with the facilities under their control

The impact of reliability on the productivity of railroad companies

DEFF Research Database (Denmark)

Abate, Megersa Abera; Lijesen, Mark; Pels, Eric

2013-01-01

This paper studies the relationship between reliability (proxied by punctuality) and productivity in passenger railroad services. Increasing reliability may lower productivity, as it requires inputs, that can’t be used to produce outputs. The relationship between reliability and productivity also...... runs through other factors, in which case a positive relationship may be expected. We apply data envelopment analysis and the Malmquist index approach to a panel of seven European railway systems to explore this relationship. Our empirical results suggest that increasing reliability does not harm...... the productivity of railway operations and aiming to improve both may be a feasible strategy. © 2013 Elsevier Ltd. All rights reserved....

Fiber Access Networks: Reliability Analysis and Swedish Broadband Market

Science.gov (United States)

Wosinska, Lena; Chen, Jiajia; Larsen, Claus Popp

Fiber access network architectures such as active optical networks (AONs) and passive optical networks (PONs) have been developed to support the growing bandwidth demand. Whereas particularly Swedish operators prefer AON, this may not be the case for operators in other countries. The choice depends on a combination of technical requirements, practical constraints, business models, and cost. Due to the increasing importance of reliable access to the network services, connection availability is becoming one of the most crucial issues for access networks, which should be reflected in the network owner's architecture decision. In many cases protection against failures is realized by adding backup resources. However, there is a trade off between the cost of protection and the level of service reliability since improving reliability performance by duplication of network resources (and capital expenditures CAPEX) may be too expensive. In this paper we present the evolution of fiber access networks and compare reliability performance in relation to investment and management cost for some representative cases. We consider both standard and novel architectures for deployment in both sparsely and densely populated areas. While some recent works focused on PON protection schemes with reduced CAPEX the current and future effort should be put on minimizing the operational expenditures (OPEX) during the access network lifetime.

Reliability Analysis of a Two Dissimilar Unit Cold Standby System ...

African Journals Online (AJOL)

(2009) using linear first order differential equation evaluated the reliability and availability characteristics of two-dissimilar-unit cold standby system with three mode for which no cost benefit analysis was considered. El-said (1994) contributed on stochastic analysis of a two-dissimilar-unit standby redundant system.

Nondestructive examination (NDE) Reliability for Inservice Inspection of Light Water Reactors

International Nuclear Information System (INIS)

Doctor, S.R.; Good, M.S.; Heasler, P.G.; Hockey, R.L.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.; Vo, T.V.

1992-07-01

The Evaluation and Improvement of NDE reliability for Inservice Inspection of Light Water Reactors (NDE Reliability) Program at the Pacific Northwest Laboratory was established by the Nuclear Regulatory Commission to determine the reliability of current inservice inspection (ISI) techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this program include determining the reliability of ISI performed on the primary systems of commercial light-water reactors (LWRs); using probabilistic fracture mechanics analysis to determine the impact of NDE unreliability on system safety; and evaluating reliability improvements that can be achieved with improved and advanced technology. A final objective is to formulate recommended revisions to the Regulatory and ASME Code requirements, based on material properties, service conditions, and NDE uncertainties

Regulating a Monopoly Offering Priority Service

OpenAIRE

Matsukawa, Isamu

2006-01-01

This paper investigates the effects of alternative forms of regulation on the market penetration and capacity, which are determined by a profit-maximizing monopolist providing priority service to consumers. For continuous priority service, a minimum reliability standard, price cap and rate of return regulation lead to larger capacity than in the absence of regulation. A minimum reliability standard reduces the market penetration while price cap and rate of return regulation increase it. T...

Reliable Radio Access for Massive Machine-to-Machine (M2M) Communication

DEFF Research Database (Denmark)

Madueño, Germán Corrales

the service requirements can range from massive number of devices to ultra-reliable. This PhD thesis focuses on novel mechanisms to meet these requirements in a variety of wireless systems, from well-established technologies such as cellular networks, to emerging technologies like IEEE 802.11ah. Today...... an overwhelming 89% of the deployed M2M modules are GPRS-based. This motivates us to investigate the potential of GPRS as a dedicated M2M network. We show that by introducing minimal modifications to GPRS operation, a large number of devices can be reliably supported. Surprisingly, even though LTE is seen...... as the preferable solution for M2M, no mechanisms are in place to guarantee reliable M2M access. Contrary to mainstream solutions that focus on preventing overload, we introduce mechanisms to provide reliable M2M service. We also investigate what cellular networks can do about upcoming smart metering traffic...

Reliability assessment of aging structures subjected to gradual and shock deteriorations

International Nuclear Information System (INIS)

Wang, Cao; Zhang, Hao; Li, Quanwang

2017-01-01

Civil structures and infrastructure facilities are susceptible to deterioration posed by the effects of natural hazards and aggressive environmental conditions. These factors may increase the risk of service interruption of infrastructures, and should be taken into account when assessing the structural reliability during an infrastructure's service life. Modeling the resistance deterioration process reasonably is the basis for structural reliability analysis. In this paper, a novel model is developed for describing the deterioration of aging structures. The deterioration is a combination of two stochastic processes: the gradual deterioration posed by environmental effects and the shock deterioration caused by severe load attacks. The dependency of the deterioration magnitude on the load intensity is considered. The Gaussian copula function is employed to help construct the joint distribution of correlated random variables. Semi-analytical methods are developed to assess the structural failure time and the number of significant load events (shocks) to failure. Illustrative examples are presented to demonstrate the applicability of the proposed model in structural reliability analysis. Parametric studies are performed to investigate the role of deterioration-load correlation in structural reliability. - Highlights: • A new resistance deterioration model for aging structures is proposed. • Time-dependent reliability analysis methods incorporating the proposed deterioration model are developed. • Parametric studies are performed to investigate the role of deterioration-load correlation in structural reliability.

Measuring the perceived quality of ophthalmology services in private organizations. A marketing perspective

Science.gov (United States)

Gheorghe, Iuliana Raluca; Gheorghe, Consuela-Mădălina; Purcărea, Victor Lorin

2018-01-01

Nowadays, the competition registered on the Romanian markets regarding the activity of private ophthalmology organizations has raised their interest in developing consumer-oriented strategies. The key factor that assures a differentiation as well as a competitive advantage is the service quality from a marketing perspective. Objectives: From a marketing perspective, service quality is measured as a perceived discrepancy between the consumers’ expectations and was actually performed in health care services. The most widely and validated measurement is the SERVQUAL scale. However, a variety of SERVQUAL scales have been applied in different health care environments without taking into consideration the specialty of the health care service. Thus, the objective of this paper was to measure the service quality in the Romanian ophthalmology private organizations using the SERVQUAL measurement, by identifying the SERVQUAL dimensions, which register the highest and the lowest gap scores. Materials and methods: The instrument for data collection was the SERVQUAL self-administered questionnaire that consisted of 22 items measured on a 5-point Likert scale. The sample size encompassed 100 participants and the sampling technique was the snowball. The internal consistency, validity and the reliability of the SERVQUAL scale was determined by the Cronbach’s alpha coefficients and factor analysis. The SERVQUAL questionnaire focused on 5 dimensions (tangibles, reliability, assurance, empathy and responsiveness) and each dimension, in its turn, was characterized by different items. Results: The mean age of the participants was 49.52 years, with a mean income of 3031 Romanian Currency and the mean period of wearing eyeglasses was 5 years (±2). Further, there were 47% females and 53% males. The overall internal consistency of the SERVQUAL scale, as well as the dimensions’ internal consistency were all above 0.7 and the factor analysis revealed that the items loaded properly on

Measuring the perceived quality of ophthalmology services in private organizations. A marketing perspective.

Science.gov (United States)

Gheorghe, Iuliana Raluca; Gheorghe, Consuela-Mădălina; Purcărea, Victor Lorin

2018-01-01

Nowadays, the competition registered on the Romanian markets regarding the activity of private ophthalmology organizations has raised their interest in developing consumer-oriented strategies. The key factor that assures a differentiation as well as a competitive advantage is the service quality from a marketing perspective. From a marketing perspective, service quality is measured as a perceived discrepancy between the consumers' expectations and was actually performed in health care services. The most widely and validated measurement is the SERVQUAL scale. However, a variety of SERVQUAL scales have been applied in different health care environments without taking into consideration the specialty of the health care service. Thus, the objective of this paper was to measure the service quality in the Romanian ophthalmology private organizations using the SERVQUAL measurement, by identifying the SERVQUAL dimensions, which register the highest and the lowest gap scores. The instrument for data collection was the SERVQUAL self-administered questionnaire that consisted of 22 items measured on a 5-point Likert scale. The sample size encompassed 100 participants and the sampling technique was the snowball. The internal consistency, validity and the reliability of the SERVQUAL scale was determined by the Cronbach's alpha coefficients and factor analysis. The SERVQUAL questionnaire focused on 5 dimensions (tangibles, reliability, assurance, empathy and responsiveness) and each dimension, in its turn, was characterized by different items. The mean age of the participants was 49.52 years, with a mean income of 3031 Romanian Currency and the mean period of wearing eyeglasses was 5 years (±2). Further, there were 47% females and 53% males. The overall internal consistency of the SERVQUAL scale, as well as the dimensions' internal consistency were all above 0.7 and the factor analysis revealed that the items loaded properly on each dimension. Moreover, the gap scores of the

Study of redundant Models in reliability prediction of HXMT's HES

International Nuclear Information System (INIS)

Wang Jinming; Liu Congzhan; Zhang Zhi; Ji Jianfeng

2010-01-01

Two redundant equipment structures of HXMT's HES are proposed firstly, the block backup and dual system cold-redundancy. Then prediction of the reliability is made by using parts count method. Research of comparison and analysis is also performed on the two proposals. A conclusion is drawn that a higher reliability and longer service life could be offered by taking a redundant equipment structure of block backup. (authors)

Development and Psychometric Testing of a Novel Food Service Satisfaction Questionnaire for Food Service Staff of Aged Care Homes.

Science.gov (United States)

Miller, M; Hamilton, J; Scupham, R; Matwiejczyk, L; Prichard, I; Farrer, O; Yaxley, A

2018-01-01

Food service staff are integral to delivery of quality food in aged care homes yet measurement of their satisfaction is unable to be performed due to an absence of a valid and reliable questionnaire. The aim of this study was to develop and perform psychometric testing for a new Food Service Satisfaction Questionnaire developed in Australia specifically for use by food service staff working in residential aged care homes (Flinders FSSQFSAC). A mixed methods design utilizing both a qualitative (in-depth interviews, focus groups) and a quantitative approach (cross sectional survey) was used. Content validity was determined from focus groups and interviews with food service staff currently working in aged care homes, related questionnaires from the literature and consultation with an expert panel. The questionnaire was tested for construct validity and internal consistency using data from food service staff currently working in aged care homes that responded to an electronic invitation circulated to Australian aged care homes using a national database of email addresses. Construct validity was tested via principle components analysis and internal consistency through Cronbach's alpha. Temporal stability of the questionnaire was determined from food service staff undertaking the Flinders FSSQFSAC on two occasions, two weeks apart, and analysed using Pearson's correlations. Content validity for the Flinders FSSQFSAC was established from a panel of experts and stakeholders. Principle components analysis revealed food service staff satisfaction was represented by 61-items divided into eight domains: job satisfaction (α=0.832), food quality (α=0.871), staff training (α=0.922), consultation (α=0.840), eating environment (α=0.777), reliability (α=0.695), family expectations (α=0.781) and resident relationships (α=0.429), establishing construct validity in all domains, and internal consistency in all (α>0.5) except for "resident relationships" (α=0.429). Test

Development of the Centralized Reliability Data Organization (CREDO)

International Nuclear Information System (INIS)

Haas, P.M.; Bott, T.F.; Knee, H.E.; Manning, J.J.; Hudson, S.D.; Greene, N.M.; Woodside, M.A.

1979-01-01

CREDO has been established to meet the needs of the US Breeder Reactor Program and the advanced reactor community for a centralized source of accurate reliability/maintainability data and data-related services. The center provides for a comprehensive program of collection, evaluation, and dissemination of data and for necessary user services. A steering committee of nationally recognized experts has been formed to guide CREDO development and operation. Historic data have been collected, analyzed, and published. Routine, continuous data collection and processing has been initiated at US sites. Interfaces with existing data bases have been established. Special user services are under development

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.

Differential in Utilization of Maternal Care Services in Empowered Action Group States, India (1990-2006

Directory of Open Access Journals (Sweden)

Jeetendra Yadav

2016-03-01

Full Text Available Background: Low use of maternal care services is one of the reasons why child mortality and maternal mortality is still considerably high in India. Most maternal deaths are preventable if mothers receive essential health care before, during, and after childbirth. In India, the eight socioeconomically backward states referred to as the Empowered Action Group (EAG states; lag behind in the demographic transition and low utilization of maternal health care services. Addressing the maternity care needs of women may have considerable ramifications for achieving the Millennium Development Goal (MDG – 5.Aims & Objectives:  To explore the prevalence, trends and factors associated with the utilization of maternal care services in Empowered Action Group States, India (1990-2006.Material Methods: Data from three rounds of the round of the Demographic and Health Survey (DHS, known as the National Family Health Survey (NFHS of India were analyzed. Bivariate and multivariate-pooled logistic regression model were applied to examine the utilization of the maternal and child health care trends over time.Result: The results from analysis indicate that the full ANC and skilled birth attendant (SBA has increased from 17% and 20% to 25% and35% respectively during the last one and half decade (1990-2006.Conclusion: Various socioeconomic and demographic factors are associated with the utilization of maternal care services in EAG states, India. Promoting the use of family planning, female education, targeting vulnerable groups such as poor, illiterate, high parity women, involving media and grass root level workers and collaboration between community leaders and health care system could be some important policy level interventions to address the unmet need of maternal and child health care services among women. The study concludes that much of these differentials are social constructs that can be reduced by prioritizing the needs of the disadvantaged and adopting

Differential in Utilization of Maternal Care Services in Empowered Action Group States, India (1990-2006

Directory of Open Access Journals (Sweden)

Jeetendra Yadav

2016-03-01

Full Text Available Background: Low use of maternal care services is one of the reasons why child mortality and maternal mortality is still considerably high in India. Most maternal deaths are preventable if mothers receive essential health care before, during, and after childbirth. In India, the eight socioeconomically backward states referred to as the Empowered Action Group (EAG states; lag behind in the demographic transition and low utilization of maternal health care services. Addressing the maternity care needs of women may have considerable ramifications for achieving the Millennium Development Goal (MDG – 5. Aims & Objectives:  To explore the prevalence, trends and factors associated with the utilization of maternal care services in Empowered Action Group States, India (1990-2006. Material Methods: Data from three rounds of the round of the Demographic and Health Survey (DHS, known as the National Family Health Survey (NFHS of India were analyzed. Bivariate and multivariate-pooled logistic regression model were applied to examine the utilization of the maternal and child health care trends over time. Result: The results from analysis indicate that the full ANC and skilled birth attendant (SBA has increased from 17% and 20% to 25% and35% respectively during the last one and half decade (1990-2006. Conclusion: Various socioeconomic and demographic factors are associated with the utilization of maternal care services in EAG states, India. Promoting the use of family planning, female education, targeting vulnerable groups such as poor, illiterate, high parity women, involving media and grass root level workers and collaboration between community leaders and health care system could be some important policy level interventions to address the unmet need of maternal and child health care services among women. The study concludes that much of these differentials are social constructs that can be reduced by prioritizing the needs of the disadvantaged and

The computer vision in the service of safety and reliability in steam generators inspection services

International Nuclear Information System (INIS)

Pineiro Fernandez, P.; Garcia Bueno, A.; Cabrera Jordan, E.

2012-01-01

The actual computational vision has matured very quickly in the last ten years by facilitating new developments in various areas of nuclear application allowing to automate and simplify processes and tasks, instead or in collaboration with the people and equipment efficiently. The current computer vision (more appropriate than the artificial vision concept) provides great possibilities of also improving in terms of the reliability and safety of NPPS inspection systems.

reliability analysis of a two span floor designed according

African Journals Online (AJOL)

user

deterministic approach, considering both ultimate and serviceability limit states. Reliability analysis of the floor ... loading, strength and stiffness parameters, dimensions .... to show that there is a direct relation between the failure probability (Pf) ...

Wind power plant system services

DEFF Research Database (Denmark)

Basit, Abdul; Altin, Müfit

Traditionally, conventional power plants have the task to support the power system, by supplying power balancing services. These services are required by the power system operators in order to secure a safe and reliable operation of the power system. However, as in the future the wind power...... is going more and more to replace conventional power plants, the sources of conventional reserve available to the system will be reduced and fewer conventional plants will be available on-line to share the regulation burden. The reliable operation of highly wind power integrated power system might...... then beat risk unless the wind power plants (WPPs) are able to support and participate in power balancing services. The objective of this PhD project is to develop and analyse control strategies which can increase the WPPs capability to provide system services, such as active power balancing control...

Are consumer surveys valuable as a service improvement tool in health services? A critical appraisal.

Science.gov (United States)

Patwardhan, Anjali; Patwardhan, Prakash

2009-01-01

In the recent climate of consumerism and consumer focused care, health and social care needs to be more responsive than ever before. Consumer needs and preferences can be elicited with accepted validity and reliability only by strict methodological control, customerisation of the questionnaire and skilled interpretation. To construct, conduct, interpret and implement improved service provision, requires a trained work force and infrastructure. This article aims to appraise various aspects of consumer surveys and to assess their value as effective service improvement tools. The customer is the sole reason organisations exist. Consumer surveys are used worldwide as service and quality of care improvement tools by all types of service providers including health service providers. The article critically appraises the value of consumer surveys as service improvement tools in health services tool and its future applications. No one type of survey is the best or ideal. The key is the selection of the correct survey methodology, unique and customised for the particular type/aspect of care being evaluated. The method used should reflect the importance of the information required. Methodological rigor is essential for the effectiveness of consumer surveys as service improvement tools. Unfortunately so far there is no universal consensus on superiority of one particular methodology over another or any benefit of one specific methodology in a given situation. More training and some dedicated resource allocation is required to develop consumer surveys. More research is needed to develop specific survey methodology and evaluation techniques for improved validity and reliability of the surveys as service improvement tools. Measurement of consumer preferences/priorities, evaluation of services and key performance scores, is not easy. Consumer surveys seem impressive tools as they provide the customer a voice for change or modification. However, from a scientific point

Assessment of the Reliability Profiles for Concrete Bridges

DEFF Research Database (Denmark)

Thoft-Christensen, Palle

In this paper calculation of reliability profiles is discussed. ULS as well as SLS limit states are formulated. Corrosion due to chloride penetration is the considered deterioration mechanism. Three models for corrosion are formulated. A definition of service lifetime for concrete bridges...

Reliability In A White Rabbit Network

CERN Document Server

Lipiński, M; Wlostowski, T; Prados, C

2011-01-01

White Rabbit (WR) is a time-deterministic, low-latency Ethernet-based network which enables transparent, subns accuracy timing distribution. It is being developed to replace the General Machine Timing (GMT) system currently used at CERN and will become the foundation for the control system of the Facility for Antiproton and Ion Research (FAIR) at GSI. High reliability is an important issue inWR’s design, since unavailability of the accelerator’s control system will directly translate into expensive downtime of the machine. A typical WR network is required to lose not more than a single message per year. Due toWR’s complexity, the translation of this real-world-requirement into a reliability-requirement constitutes an interesting issue on its own – a WR network is considered functional only if it provides all its services to all its clients at any time. This paper defines reliability in WR and describes how it was addressed by dividing it into sub-domains: deterministic packet delivery, data resilience...

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

A Psychometric Evaluation of the DSM-IV Criteria for Antisocial Personality Disorder: Dimensionality, Local Reliability, and Differential Item Functioning Across Gender.

Science.gov (United States)

Paap, Muirne C S; Braeken, Johan; Pedersen, Geir; Urnes, Øyvind; Karterud, Sigmund; Wilberg, Theresa; Hummelen, Benjamin

2017-12-01

This study aims at evaluating the psychometric properties of the antisocial personality disorder (ASPD) criteria in a large sample of patients, most of whom had one or more personality disorders (PD). PD diagnoses were assessed by experienced clinicians using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Axis II PDs. Analyses were performed within an item response theory framework. Results of the analyses indicated that ASPD is a unidimensional construct that can be measured reliably at the upper range of the latent trait scale. Differential item functioning across gender was restricted to two criteria and had little impact on the latent ASPD trait level. Patients fulfilling both the adult ASPD criteria and the conduct disorder criteria had similar latent trait distributions as patients fulfilling only the adult ASPD criteria. Overall, the ASPD items fit the purpose of a diagnostic instrument well, that is, distinguishing patients with moderate from those with high antisocial personality scores.

Linear SVM-Based Android Malware Detection for Reliable IoT Services

Directory of Open Access Journals (Sweden)

Hyo-Sik Ham

2014-01-01

Full Text Available Current many Internet of Things (IoT services are monitored and controlled through smartphone applications. By combining IoT with smartphones, many convenient IoT services have been provided to users. However, there are adverse underlying effects in such services including invasion of privacy and information leakage. In most cases, mobile devices have become cluttered with important personal user information as various services and contents are provided through them. Accordingly, attackers are expanding the scope of their attacks beyond the existing PC and Internet environment into mobile devices. In this paper, we apply a linear support vector machine (SVM to detect Android malware and compare the malware detection performance of SVM with that of other machine learning classifiers. Through experimental validation, we show that the SVM outperforms other machine learning classifiers.

Antecedents and consequences of the service climate in boundary-spanning self-managing service teams

NARCIS (Netherlands)

Jong, de A.; Ruyter, de J.C.; Lemmink, J.G.A.M.

2004-01-01

In this article, the authors examine antecedents and consequences of the service climate in boundary-spanning self-managing teams (SMTs) that deliver financial services. Using data from members of 61 SMTs and their customers, the authors show a differential impact of the SMT service climate on

Functional Determinants for Radially Separable Partial Differential Operators

Directory of Open Access Journals (Sweden)

G. V. Dunne

2007-01-01

Full Text Available Functional determinants of differential operators play a prominent role in many fields of theoretical and mathematical physics, ranging from condensed matter physics, to atomic, molecular and particle physics. They are, however, difficult to compute reliably in non-trivial cases. In one dimensional problems (i.e. functional determinants of ordinary differential operators, a classic result of Gel’fand and Yaglom greatly simplifies the computation of functional determinants. Here I report some recent progress in extending this approach to higher dimensions (i.e., functional determinants of partial differential operators, with applications in quantum field theory. 

Robo advisor, your reliable partner? Building a trustworthy digital investment management service

OpenAIRE

Salo, Anni

2017-01-01

Investment management services have strongly relied on traditional face-to-face business models, causing the services being highly expensive and therefore available only for the wealthiest population. Recently a new digital business model, robo advisors, entered the market and are predicted to democratise the entire industry by bringing investment management services available to a wider public than ever before. Although the business models in financial services are changing, customer tr...

Decentralized Fault Management for Service Dependability in Ubiquitous Networks

DEFF Research Database (Denmark)

Grønbæk, Lars Jesper

2010-01-01

) unobservable and incomplete network state information, ii) unreliable observations, and iii) dynamic environments calling for adaptation in the fault management process. In the study, focus is on potential gains in the interaction between the components of Observation, Diagnosis, Decision and Remediation...... insights on the impact of unavoidable diagnosis imperfections on service reliability. Also, it is studied to what extent good remediation decisions may be applied to mitigate such imperfections. For this purpose a light-weight decision policy evaluation model is proposed and verified in a system level...... simulation model. Some of the main findings are: i) certain imperfection trade-off settings of the Diagnosis component lead to worse end-user service reliability than if no fault management is conducted, ii) using end-user service state information in the decision process can help improve service reliability...

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.

Techniques for increasing the reliability of accelerator control system electronics

International Nuclear Information System (INIS)

Utterback, J.

1993-09-01

As the physical size of modern accelerators becomes larger and larger, the number of required control system circuit boards increases, and the probability of one of those circuit boards failing while in service also increases. In order to do physics, the experimenters need the accelerator to provide beam reliably with as little down time as possible. With the advent of colliding beams physics, reliability becomes even more important due to the fact that a control system failure can cause the loss of painstakingly produced antiprotons. These facts prove the importance of keeping reliability in mind when designing and maintaining accelerator control system electronics

Reliability estimation for multiunit nuclear and fossil-fired industrial energy systems

International Nuclear Information System (INIS)

Sullivan, W.G.; Wilson, J.V.; Klepper, O.H.

1977-01-01

As petroleum-based fuels grow increasingly scarce and costly, nuclear energy may become an important alternative source of industrial energy. Initial applications would most likely include a mix of fossil-fired and nuclear sources of process energy. A means for determining the overall reliability of these mixed systems is a fundamental aspect of demonstrating their feasibility to potential industrial users. Reliability data from nuclear and fossil-fired plants are presented, and several methods of applying these data for calculating the reliability of reasonably complex industrial energy supply systems are given. Reliability estimates made under a number of simplifying assumptions indicate that multiple nuclear units or a combination of nuclear and fossil-fired plants could provide adequate reliability to meet industrial requirements for continuity of service

76 FR 80249 - Use of Differential Income Stream as a Consideration in Assessing the Best Method

Science.gov (United States)

2011-12-23

... alternative discounted at the rate appropriate for the licensing alternative, and evaluating reliability... the reliability of a determination of the arm's length charge for the PCT Payment. Accordingly, these... present value of the differential income stream is consistent with reliable direct evidence of the...

The relative importance of service dimensions in a healthcare setting.

Science.gov (United States)

Ramsaran-Fowdar, Rooma Roshnee

2008-01-01

The paper aims to focus on an augmented SERVQUAL instrument that was used to measure private patients' service expectations and perceptions. A questionnaire was administered to 750 and 34 per cent responded. A new service quality instrument called PRIVHEALTHQUAL emerged from the study, based on factor and reliability analysis. The "reliability and fair and equitable treatment" factor was found to be the most important healthcare service quality dimension. Adds to the existing body of research on service quality and demonstrates that SERVQUAL is not a generic service quality measure for all industries.

Service reliability assessment using failure mode and effect analysis ...

African Journals Online (AJOL)

user

Statistical Process Control Teng and Ho (1996) .... are still remaining left on modelling the interaction between impact of internal service failure and ..... Design error proofing: development of automated error-proofing information systems, Proceedings of.

Allied health clinicians using translational research in action to develop a reliable stroke audit tool.

Science.gov (United States)

Abery, Philip; Kuys, Suzanne; Lynch, Mary; Low Choy, Nancy

2018-05-23

To design and establish reliability of a local stroke audit tool by engaging allied health clinicians within a privately funded hospital. Design: Two-stage study involving a modified Delphi process to inform stroke audit tool development and inter-tester reliability. Allied health clinicians. A modified Delphi process to select stroke guideline recommendations for inclusion in the audit tool. Reliability study: 1 allied health representative from each discipline audited 10 clinical records with sequential admissions to acute and rehabilitation services. Recommendations were admitted to the audit tool when 70% agreement was reached, with 50% set as the reserve agreement. Inter-tester reliability was determined using intra-class correlation coefficients (ICCs) across 10 clinical records. Twenty-two participants (92% female, 50% physiotherapists, 17% occupational therapists) completed the modified Delphi process. Across 6 voting rounds, 8 recommendations reached 70% agreement and 2 reached 50% agreement. Two recommendations (nutrition/hydration; goal setting) were added to ensure representation for all disciplines. Substantial consistency across raters was established for the audit tool applied in acute stroke (ICC .71; range .48 to .90) and rehabilitation (ICC.78; range .60 to .93) services. Allied health clinicians within a privately funded hospital generally agreed in an audit process to develop a reliable stroke audit tool. Allied health clinicians agreed on stroke guideline recommendations to inform a stroke audit tool. The stroke audit tool demonstrated substantial consistency supporting future use for service development. This process, which engages local clinicians, could be adopted by other facilities to design reliable audit tools to identify local service gaps to inform changes to clinical practice. © 2018 John Wiley & Sons, Ltd.

Income differential of female labor in Southern Brazil: dual approach

Directory of Open Access Journals (Sweden)

Rita de Cassia Garcia Margonato

2014-06-01

Full Text Available This study analyzes the formation and income differential of female labor in Southern Brazil in 2002 and 2009 based on microdata from the National Sample Survey (PNAD.The methodology is to estimate the selection and wages equations using the Heckman's Sample Selection Model (1979. For the measurement of the female income differential in commerce, industry and domestic service, compared to income of women in the service sector it is applied an adaptation of the Oaxaca-Blinder Decomposition (1973 adapted by Jann (2008. It was confirmed the hypothesis that segmentation occurs in the female labor market in Southern Brazil because the income differential cannot be explained only by personal attributes (productive or not and by formal work. There are specificities in the sectors (sector effect determining the income differential of women´s income in the labor market, moreover the sector effect explained 33% of the wage differential observed in industry, also explained 29% in the commerce and 35% of the female income gaps when compared to the service sector, which is considered as in advantage.

Modified Differential Transform Method for Two Singular Boundary Values Problems

Directory of Open Access Journals (Sweden)

Yinwei Lin

2014-01-01

Full Text Available This paper deals with the two singular boundary values problems of second order. Two singular points are both boundary values points of the differential equation. The numerical solutions are developed by modified differential transform method (DTM for expanded point. Linear and nonlinear models are solved by this method to get more reliable and efficient numerical results. It can also solve ordinary differential equations where the traditional one fails. Besides, we give the convergence of this new method.

Coexistence of enhanced mobile broadband communications and ultra-reliable low-latency communications in mobile front-haul

Science.gov (United States)

Ying, Kai; Kowalski, John M.; Nogami, Toshizo; Yin, Zhanping; Sheng, Jia

2018-01-01

5G systems are supposed to support coexistence of multiple services such as ultra reliable low latency communications (URLLC) and enhanced mobile broadband (eMBB) communications. The target of eMBB communications is to meet the high-throughput requirement while URLLC are used for some high priority services. Due to the sporadic nature and low latency requirement, URLLC transmission may pre-empt the resource of eMBB transmission. Our work is to analyze the URLLC impact on eMBB transmission in mobile front-haul. Then, some solutions are proposed to guarantee the reliability/latency requirements for URLLC services and minimize the impact to eMBB services at the same time.

Automated Energy Distribution and Reliability System Status Report

Energy Technology Data Exchange (ETDEWEB)

Buche, D. L.; Perry, S.

2007-10-01

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

Improvement of AC motor reliability from technique standardization

International Nuclear Information System (INIS)

Muniz, P.R.; Faria, M.D.R.; Mendes, M.P.; Silva, J.N.; Dos Santos, J.D.

2005-01-01

The purpose of this paper is to explain the increase of reliability of motors serviced in the Electrical Maintenance Shop of Companhia Siderurgica de Tubarao by standardization of the technique based on Brazilian and International Standards, manufacturer's recommendations and the experience of the maintenance staff. (author)

Induction of morphological and functional differentiation of human ...

Indian Academy of Sciences (India)

Samaneh Sharif

2017-10-31

Oct 31, 2017 ... model of neuroblastoma cancer. Influence of miR-124 .... a more reliable marker for quantifying the expand of cell differentiation (Thiele et al. ..... results for children with high-risk neuroblastoma treated on a randomized trial of ...

Analysis of psychological factors for quality assessment of interactive multimodal service

Science.gov (United States)

Yamagishi, Kazuhisa; Hayashi, Takanori

2005-03-01

We proposed a subjective quality assessment model for interactive multimodal services. First, psychological factors of an audiovisual communication service were extracted by using the semantic differential (SD) technique and factor analysis. Forty subjects participated in subjective tests and performed point-to-point conversational tasks on a PC-based TV phone that exhibits various network qualities. The subjects assessed those qualities on the basis of 25 pairs of adjectives. Two psychological factors, i.e., an aesthetic feeling and a feeling of activity, were extracted from the results. Then, quality impairment factors affecting these two psychological factors were analyzed. We found that the aesthetic feeling is mainly affected by IP packet loss and video coding bit rate, and the feeling of activity depends on delay time and video frame rate. We then proposed an opinion model derived from the relationships among quality impairment factors, psychological factors, and overall quality. The results indicated that the estimation error of the proposed model is almost equivalent to the statistical reliability of the subjective score. Finally, using the proposed model, we discuss guidelines for quality design of interactive audiovisual communication services.

A k-out-of-n reliability system with an unreliable server and phase type repairs and services: the (N,T policy

Directory of Open Access Journals (Sweden)

Srinivas R. Chakravarthy

2001-01-01

Full Text Available In this paper we study a k-out-of-n reliability system in which a single unreliable server maintains n identical components. The reliability system is studied under the (N,T policy. An idle server takes a vacation for a random amount of time T and then attends to any failed component waiting in line upon completion of the vacation. The vacationing server is recalled instantaneously upon the failure of the Nth component. The failure times of the components are assumed to follow an exponential distribution. The server is subject to failure with failure times exponentially distributed. Repair times of the component, fixing times of the server, and vacationing times of the server are assumed to be of phase type. Using matrix-analytic methods we perform steady state analysis of this model. Time spent by a failed component in service, total time in the repair facility, vacation time of the server, non-vacation time of the server, and time until failure of the system are all shown to be of phase type. Several performance measures are evaluated. Illustrative numerical examples are presented.

Reliable dynamics in Boolean and continuous networks

International Nuclear Information System (INIS)

Ackermann, Eva; Drossel, Barbara; Peixoto, Tiago P

2012-01-01

We investigate the dynamical behavior of a model of robust gene regulatory networks which possess ‘entirely reliable’ trajectories. In a Boolean representation, these trajectories are characterized by being insensitive to the order in which the nodes are updated, i.e. they always go through the same sequence of states. The Boolean model for gene activity is compared with a continuous description in terms of differential equations for the concentrations of mRNA and proteins. We found that entirely reliable Boolean trajectories can be reproduced perfectly in the continuous model when realistic Hill coefficients are used. We investigate to what extent this high correspondence between Boolean and continuous trajectories depends on the extent of reliability of the Boolean trajectories, and we identify simple criteria that enable the faithful reproduction of the Boolean dynamics in the continuous description. (paper)

Tests of the Validity and Reliability of the Community Service Attitudes Scale

Science.gov (United States)

Perry, Brian; Osbaldiston, Richard; Henning, Jaime

2014-01-01

Community service is deeply rooted in American culture. There have been repeated calls for the necessity of evaluating these programs, especially for service-learning. The purpose of this research was to validate an easy-to-use scale that measures 10 components of students' attitudes toward community service. The sample was drawn from two…

Consortium for Electric Reliability Technology Solutions Grid of the Future White Paper on Review of Recent Reliability Issues and Systems Events

Energy Technology Data Exchange (ETDEWEB)

Hauer, John F.; Dagle, Jeffery E.

1999-12-01

This report is one of six reports developed under the U.S. Department of Energy (DOE) program in Power System Integration and Reliability (PSIR). The objective of this report is to review, analyze, and evaluate critical reliability issues demonstrated by recent disturbance events in the North America power system. Eleven major disturbances are examined, most occurring in this decade. The strategic challenge is that the pattern of technical need has persisted for a long period of time. For more than a decade, anticipation of market deregulation has been a major disincentive to new investments in system capacity. It has also inspired reduced maintenance of existing assets. A massive infusion of better technology is emerging as the final option to continue reliable electrical services. If an investment in better technology will not be made in a timely manner, then North America should plan its adjustments to a very different level of electrical service. It is apparent that technical operations staff among the utilities can be very effective at marshaling their forces in the immediate aftermath of a system emergency, and that serious disturbances often lead to improved mechanisms for coordinated operation. It is not at all apparent that such efforts can be sustained through voluntary reliability organizations in which utility personnel external to those organizations do most of the technical work. The eastern interconnection shows several situations in which much of the technical support has migrated from the utilities to the Independent System Operator (ISO), and the ISO staffs or shares staff with the regional reliability council. This process may be a natural and very positive consequence of utility restructuring. If so, the process should be expedited in regions where it is less advanced.

Understanding Health-related Quality of Life in Caregivers of Civilians and Service Members/Veterans with Traumatic Brain Injury: Establishing the Reliability and Validity of PROMIS Mental Health Measures.

Science.gov (United States)

Carlozzi, Noelle E; Hanks, Robin; Lange, Rael T; Brickell D Psych, Tracey A; Ianni, Phillip A; Miner, Jennifer A; French Psy D, Louis M; Kallen, Michael A; Sander, Angelle M

2018-06-19

To provide important reliability and validity data to support the use of the PROMIS Mental Health measures in caregivers of civilians or service members/veterans with traumatic brain injury (TBI). Patient-reported outcomes surveys administered through an electronic data collection platform. Three TBI Model Systems rehabilitation hospitals, an academic medical center, and a military medical treatment facility. 560 caregivers of individuals with a documented TBI (344 civilians and 216 military) INTERVENTION: Not Applicable MAIN OUTCOME MEASURES: PROMIS Anxiety, Depression, and Anger Item Banks RESULTS: Internal consistency for all of the PROMIS Mental Health item banks was very good (all α > .86) and three-week test retest reliability was good to adequate (ranged from .65 to .85). Convergent validity and discriminant validity of the PROMIS measures was also supported. Caregivers of individuals that were low functioning had worse emotional HRQOL (as measured by the three PROMIS measures) than caregivers of high functioning individuals, supporting known groups validity. Finally, levels of distress, as measured by the PROMIS measures, were elevated for those caring for low-functioning individuals in both samples (rates ranged from 26.2% to 43.6% for caregivers of low-functioning individuals). Results support the reliability and validity of the PROMIS Anxiety, Depression, and Anger item banks in caregivers of civilians and service members/veterans with TBI. Ultimately, these measures can be used to provide a standardized assessment of HRQOL as it relates to mental health in these caregivers. Copyright © 2018. Published by Elsevier Inc.

evaluation of willingness to pay for reliable and sustainable ...

African Journals Online (AJOL)

Osondu

evaluate the WTP for reliable and sustainable service delivery. The findings of the study .... In doing this, the revenue base and cost recovery will as well be enhanced in ..... delays at traffic warden controlled urban intersections: case study of ...

Financial Services and the Internet: What Does Cyberspace Mean for the Financial Services Industry?

Science.gov (United States)

Birch, David; Young, Michael A.

1997-01-01

More than 30 million households own PCs and more than 20% of these use PCs to manage their finances. This article examines the Internet and financial services, consumer needs, and differentiation in service products and predicts future trends in retail financial services (cheaper niche products, cross-border selling, selling knowledge, payments,…

Risikoorientierte Bemessung von Tragstrukturen Bedeutungsbeiwerte bei der Differenzierung der Zuverlässigkeit für unterschiedliche Schadens-bzw. Versagensfolgeklassen [ Risk oriented design of structures-Force importance factors KFI for differentiating the reliability levels of the different Consequences Classes

NARCIS (Netherlands)

Pertermann, I.; Puthli, R.; Ummenhofer, T.; Vrouwenvelder, A.C.W.M.

2012-01-01

The Eurocode EN 1990 [1] Annex B Clause B.3 allows a risk oriented differentiation of the reliability levels with the definition of different consequences classes CC1 to CC3. This can occur through decrease or increase of the safety factor for either the action or the resistance. Should the

Fuel element services

International Nuclear Information System (INIS)

Marta, H.; Alvarez, P.; Jimenez, J.

2006-01-01

Refuelling outages comprise a number of maintenance tasks scheduled long in advance to assure a reliable operation throughout the next cycle and, in the long run, a safer and more efficient plant. Most of these tasks are routine service of mechanical and electrical system and likewise fuel an be considered a critical component as to handling, inspection, cleaning and repair. ENUSA-ENWESA AIE has been working in this area since 1995 growing from fuel repair to a more integrated service that includes new and spent fuel handling, inserts, failed fuel rod detection systems, ultrasonic fuel cleaning, fuel repair and a comprehensive array of inspection and tests related to the reliability of the mechanical components in the fuel assembly, all this, performed in compliance with quality, safety, health physics and any other nuclear standard. (Author)

Studying customer loyalty at Daewoo express bus service, Pakistan

Directory of Open Access Journals (Sweden)

Usman Yousaf

2013-09-01

Full Text Available Background: Meeting service quality standards and striving for loyalty are two critical areas which have until now been overlooked by both the passenger transport industry and academia in Pakistan therefore the study sheds useful light on an issue hitherto untouched. Therefore increased sample size will help in increasing generalizability of study. Methods: This paper is designed to study the level of loyalty at Daewoo Express Bus Service in Sargodha by measuring customer satisfaction. Researchers used a small sample of only 96 respondents (passengers and only studies customer's behavior in the service quality of Daewoo Express Bus Service however it may differ in other passenger transport services. Results and conclusions: This paper reveals that there is a positive and significant relationship between loyalty (dependant variable and price perceptions, reliability, retrieving and smoothing (independent variables. However, the study found that reliability of services is the most important dimension among other independent variables (price perceptions, smoothing, reliability, retrieving effecting customers loyalty at Daewoo Express. Paper under consideration would surely assist Daewoo`s management team to take care of the loopholes existing in the current service level and likely threats which Daewoo might face.

Enhanced Reliability of Photovoltaic Systems with Energy Storage and Controls

Energy Technology Data Exchange (ETDEWEB)

Manz, D.; Schelenz, O.; Chandra, R.; Bose, S.; de Rooij, M.; Bebic, J.

2008-02-01

This report summarizes efforts to reconfigure loads during outages to allow individual customers the opportunity to enhance the reliability of their electric service through the management of their loads, photovoltaics, and energy storage devices.

Load As A Reliability Resource in the Restructured Electricity Market

Energy Technology Data Exchange (ETDEWEB)

Kueck, J.D.

2002-06-10

Recent electricity price spikes are painful reminders of the value that meaningful demand-side responses could bring to the restructuring US electricity system. Review of the aggregate offers made by suppliers confirms that even a modest increase in demand elasticity could dramatically reduce these extremes in price volatility. There is a strong need for dramatically increased customer participation in these markets to enhance system reliability and reduce price volatility. Indeed, allowing customers to manage their loads in response to system conditions might be thought of as the ultimate reliability resource. Most would agree that meaningful demand-side responses to price are the hallmark of a well-functioning competitive market [1]. Yet, in today's markets for electricity, little or no such response is evident. The reason is simple: customers currently do not experience directly the time-varying costs of their consumption decisions. Consequently, they have no incentive to modify these decisions in ways that might enhance system reliability or improve the efficiency of the markets in which electricity is traded. Increased customer participation is a necessary step in the evolution toward more efficient markets for electricity and ancillary services. This scoping report provides a three-part assessment of the current status of efforts to enhance the ability of customer's load to participate in competitive markets with a specific focus on the role of customer loads in enhancing electricity system reliability. First, this report considers the definitions of electricity-reliability-enhancing ancillary services (Section 2) and a preliminary assessment of the ability of customer's loads to provide these services. Second, is a review a variety of programs in which load has been called on as a system reliability resource (Section 3). These experiences, drawn from both past and current utility and ISO programs, focus on programs triggered by system

Fiscal competition and regional differentiation

OpenAIRE

Justman, Moshe; Thisse, Jacques-François; Van Ypersele, Tanguy

2001-01-01

Regions can benefit by offering infrastructure services that are differentiated. Competition between regions over potential investors is then less direct, allowing them to realize greater benefits from external investors. The two polar cases of full and incomplete information about investors' needs are studied. In both cases, there is regional differentiation. However, fiscal competition is efficient in the former case but not in the latter. Finally, it is shown that free entry in the loc...

Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs with Extended Service Range

Science.gov (United States)

Choi, Woo-Yong

2011-11-01

In this paper, we propose the efficient reliable multicast MAC protocol by which the AP (Access Point) can transmit reliably its multicast data frames to the recipients in the AP's one-hop or two-hop transmission range. The AP uses the STAs (Stations) that are directly associated with itself as the relays for the data delivery to the remote recipients that cannot be reached directly from itself. Based on the connectivity information among the recipients, the reliable multicast MAC protocol optimizes the number of the RAK (Request for ACK) frame transmissions in a reasonable computational time. Numerical examples show that our proposed MAC protocol significantly enhances the MAC performance compared with the BMMM (Batch Mode Multicast MAC) protocol that is extended to support the recipients that are in the AP's one-hop or two-hop transmission range in IEEE 802.11 wireless LANs.

Reliability of Broadcast Communications Under Sparse Random Linear Network Coding

OpenAIRE

Brown, Suzie; Johnson, Oliver; Tassi, Andrea

2018-01-01

Ultra-reliable Point-to-Multipoint (PtM) communications are expected to become pivotal in networks offering future dependable services for smart cities. In this regard, sparse Random Linear Network Coding (RLNC) techniques have been widely employed to provide an efficient way to improve the reliability of broadcast and multicast data streams. This paper addresses the pressing concern of providing a tight approximation to the probability of a user recovering a data stream protected by this kin...

Factor Structure and Reliability of Test Items for Saudi Teacher Licence Assessment

Science.gov (United States)

Alsadaawi, Abdullah Saleh

2017-01-01

The Saudi National Assessment Centre administers the Computer Science Teacher Test for teacher certification. The aim of this study is to explore gender differences in candidates' scores, and investigate dimensionality, reliability, and differential item functioning using confirmatory factor analysis and item response theory. The confirmatory…

DIRAC: reliable data management for LHCb

International Nuclear Information System (INIS)

Smith, A C; Tsaregorodtsev, A

2008-01-01

DIRAC, LHCb's Grid Workload and Data Management System, utilizes WLCG resources and middleware components to perform distributed computing tasks satisfying LHCb's Computing Model. The Data Management System (DMS) handles data transfer and data access within LHCb. Its scope ranges from the output of the LHCb Online system to Grid-enabled storage for all data types. It supports metadata for these files in replica and bookkeeping catalogues, allowing dataset selection and localization. The DMS controls the movement of files in a redundant fashion whilst providing utilities for accessing all metadata. To do these tasks effectively the DMS requires complete self integrity between its components and external physical storage. The DMS provides highly redundant management of all LHCb data to leverage available storage resources and to manage transient errors in underlying services. It provides data driven and reliable distribution of files as well as reliable job output upload, utilizing VO Boxes at LHCb Tier1 sites to prevent data loss. This paper presents several examples of mechanisms implemented in the DMS to increase reliability, availability and integrity, highlighting successful design choices and limitations discovered

Linking Service Quality Attributes To Customer Satisfaction in The ...

African Journals Online (AJOL)

The purpose of the study was to determine the service quality dimensions of mobile phone services-network performance, service reliability and service accessibility, and to ex-amine the service quality/customer satisfaction link within the context of mobile phone services. An exploratory research design using a quantitative ...

Cloud services, networking, and management

CERN Document Server

da Fonseca, Nelson L S

2015-01-01

Cloud Services, Networking and Management provides a comprehensive overview of the cloud infrastructure and services, as well as their underlying management mechanisms, including data center virtualization and networking, cloud security and reliability, big data analytics, scientific and commercial applications. Special features of the book include: State-of-the-art content. Self-contained chapters for readers with specific interests. Includes commercial applications on Cloud (video services and games).

System ergonomics as an approach to improve human reliability

International Nuclear Information System (INIS)

Bubb, H.

1988-01-01

The application of system technics on ergonomical problems is called system ergonomics. This enables improvements of human reliability by design measures. The precondition for this is the knowledge of how information processing is performed by man and machine. By a separate consideration of sensory processing, cognitive processing, and motory processing it is possible to have a more exact idea of the system element 'man'. The system element 'machine' is well described by differential equations which allow an ergonomical assessment of the manouverability. The knowledge of information processing of man and machine enables a task analysis. This makes appear on one hand the human boundaries depending on the different properties of the task and on the other hand suitable ergonomical solution proposals which improve the reliability of the total system. It is a disadvantage, however, that the change of human reliability by such measures may not be quoted numerically at the moment. (orig.)

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.)

Sigma: computer vision in the service of safety and reliability in the inspection services

International Nuclear Information System (INIS)

Pineiro, P. J.; Mendez, M.; Garcia, A.; Cabrera, E.; Regidor, J. J.

2012-01-01

Vision Computing is growing very fast in the last decade with very efficient tools and algorithms. This allows new development of applications in the nuclear field providing more efficient equipment and tasks: redundant systems, vision-guided mobile robots, automated visual defects recognition, measurement, etc., In this paper Tecnatom describes a detailed example of visual computing application developed to provide secure redundant identification of the thousands of tubes existing in a power plant steam generator. some other on-going or planned visual computing projects by Tecnatom are also introduced. New possibilities of application in the inspection systems for nuclear components appear where the main objective is to maximize their reliability. (Author) 6 refs.

Partial differential equations

CERN Document Server

Sloan, D; Süli, E

2001-01-01

/homepage/sac/cam/na2000/index.html7-Volume Set now available at special set price ! Over the second half of the 20th century the subject area loosely referred to as numerical analysis of partial differential equations (PDEs) has undergone unprecedented development. At its practical end, the vigorous growth and steady diversification of the field were stimulated by the demand for accurate and reliable tools for computational modelling in physical sciences and engineering, and by the rapid development of computer hardware and architecture. At the more theoretical end, the analytical insight in

Practice of value-based distribution reliability assessment (VBDRA) at Scarborough Public Utilities

International Nuclear Information System (INIS)

Chen, R-L.

1995-01-01

The development of value-based distribution reliability assessment (VBDRA) at Scarborough Public Utilities was described. Load point reliability indices, customer interruption costs (CIC), continuity and service reliability, accuracy of CIC, and the aspects of application of VBDRA were addressed. The application of VBDRA to a long-term rebuild plan for 4.16 kV distribution system was described. The importance of a cost-benefit analysis for implementation of VBDRA was emphasized. In the case of the Scarborough Public Utilities Commission the enhanced feeder reliability assessment was found to influence the allocation of funding to where it provided the most value to customers. 14 refs., 3 tabs., 3 figs

Estimation of electromagnetic pumps reliability based on the results of their exploitation

International Nuclear Information System (INIS)

Vitkovskij, I.V.; Kirillov, I.R.; Chajka, P.Yu.; Kryuchkov, E.A.; Poplavskij, V.M.; Nosov, Yu.V.; Oshkanov, N.N.

2007-01-01

Main factors, determining the service life of induction electromagnetic pumps (IEP), are analyzed. It is shown that the IEP serviceability depends mainly on the winding reliability. The main damaging factors, acting on the windings, are noted. The expressions for calculation of the failure intensity for the coil and case insulations are obtained [ru

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.

Multimedia Services in Open Distributed Telecommunications Environments

NARCIS (Netherlands)

Leydekkers, Peter

1997-01-01

The design and analysis of transport protocols for reliable communications constitutes the topic of this dissertation. These transport protocols guarantee the sequenced and complete delivery of user data over networks which may lose, duplicate and reorder packets. Reliable transport services are

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.)

Reliability study: steam generation and distribution system, Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Baker, F.E.; Davis, E.L.; Dent, J.T.; Walters, D.E.; West, R.M.

1982-10-01

A reliability study for determining the ability of the Steam Generation and Distribution System to provide reliable and adequate service through the year 2000 has been completed. This study includes an evaluation of the X-600 Steam Plant and the steam distribution system. The Steam Generation and Distribution System is in good overall condition, but to maintain this condition, the reliability study team made twelve recommendations. Eight of the recommendations are for repair or replacement of existing equipment and have a total estimated cost of $540,000. The other four recommendations are for additional testing, new procedure implementation, or continued investigations

Differentiation of 2- and 6-isomers of (2-dimethylaminopropylbenzofuran by tandem mass spectrometry

Directory of Open Access Journals (Sweden)

V. A. Shevyrin

2016-07-01

Full Text Available Reliable identification of new psychoactive substances of 2-(2-methylaminopropylbenzofuran and 6-(2-methylaminopropylbenzofuran is problematic when analyzing by gas chromatography–mass spectrometry method. It found that these two isomers can be reliably differentiated by MS/MS spectra obtained by collision-induced dissociation of their protonated molecules.

On the application of nonhomogeneous Poisson process to the reliability analysis of service water pumps of nuclear power plants

International Nuclear Information System (INIS)

Cruz Saldanha, Pedro Luiz da.

1995-12-01

The purpose of this study is to evaluate the nonhomogeneous Poisson process as a model to rate of occurrence of failures when it is not constant, and the times between failures are not independent nor identically distributed. To this evaluation, an analyse of reliability of service water pumps of a typical nuclear power plant is made considering the model discussed in the last paragraph, as long as the pumps are effectively repairable components. Standard statistical techniques, such as maximum likelihood and linear regression, are applied to estimate parameters of nonhomogeneous Poisson process model. As a conclusion of the study, the nonhomogeneous Poisson process is adequate to model rate of occurrence of failures that are function of time, and can be used where the aging mechanisms are present in operation of repairable systems. (author). 72 refs., 45 figs., 21 tabs

Reliability-based design code calibration for concrete containment structures

International Nuclear Information System (INIS)

Han, B.K.; Cho, H.N.; Chang, S.P.

1991-01-01

In this study, a load combination criteria for design and a probability-based reliability analysis were proposed on the basis of a FEM-based random vibration analysis. The limit state model defined for the study is a serviceability limit state of the crack failure that causes the emission of radioactive materials, and the results are compared with the case of strength limit state. More accurate reliability analyses under various dynamic loads such as earthquake loads were made possible by incorporating the FEM and random vibration theory, which is different from the conventional reliability analysis method. The uncertainties in loads and resistance available in Korea and the references were adapted to the situation of Korea, and especially in case of earthquake, the design earthquake was assessed based on the available data for the probabilistic description of earthquake ground acceleration in the Korea peninsula. The SAP V-2 is used for a three-dimensional finite element analysis of concrete containment structure, and the reliability analysis is carried out by modifying HRAS reliability analysis program for this study. (orig./GL)

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.

The reliability of differentiating neurogenic claudication from vascular claudication based on symptomatic presentation.

Science.gov (United States)

Nadeau, Mélissa; Rosas-Arellano, M Patricia; Gurr, Kevin R; Bailey, Stewart I; Taylor, David C; Grewal, Ruby; Lawlor, D Kirk; Bailey, Chris S

2013-12-01

Intermittent claudication can be neurogenic or vascular. Physicians use a profile based on symptom attributes to differentiate the 2 types of claudication, and this guides their investigations for diagnosis of the underlying pathology. We evaluated the validity of these symptom attributes in differentiating neurogenic from vascular claudication. Patients with a diagnosis of lumbar spinal stenosis (LSS) or peripheral vascular disease (PVD) who reported claudication answered 14 questions characterizing their symptoms. We determined the sensitivity, specificity and positive and negative likelihood ratios (PLR and NLR) for neurogenic and vascular claudication for each symptom attribute. We studied 53 patients. The most sensitive symptom attribute to rule out LSS was the absence of "triggering of pain with standing alone" (sensitivity 0.97, NLR 0.050). Pain alleviators and symptom location data showed a weak clinical significance for LSS and PVD. Constellation of symptoms yielded the strongest associations: patients with a positive shopping cart sign whose symptoms were located above the knees, triggered with standing alone and relieved with sitting had a strong likelihood of neurogenic claudication (PLR 13). Patients with symptoms in the calf that were relieved with standing alone had a strong likelihood of vascular claudication (PLR 20.0). The classic symptom attributes used to differentiate neurogenic from vascular claudication are at best weakly valid independently. However, certain constellation of symptoms are much more indicative of etiology. These results can guide general practitioners in their evaluation of and investigation for claudication.

Public transportation systems: Comparative analysis of quality of service

Energy Technology Data Exchange (ETDEWEB)

Negri, L.; Florio, L. (Rome Univ. La Sapienza (Italy). Facolta' di Ingegneria, Dipt. di Idraulica, Trasporti e Strade)

The evaluation, choice and design of public transportation systems for urban areas requires, in addition to consolidated use parameters, other dimensions essential to supply-demand qualiflcative realignment, e.g.: 'door-to-door time' which allows system differentiation in terms of commercial velocity, frequency and length of route; technical productivity expressed as 'transport power' and 'specific transport power'; and 'system/service quality'. By the means of surveys, these factors can be incorporated into suitable mathematical models representing, in a complete and reliable way, all the functions which a given system actually delivers and those functions which it is expected to deliver by its users. This paper illustrates the application of these concepts in a comparative analysis of different public transportation options - light rail rapid transit, tram and bus networks.

Jitter reduction in Differentiated Services (Diffserv) networks

NARCIS (Netherlands)

Karagiannis, Georgios; Rexhepi, Vlora

2001-01-01

A method and a computer program for reducing jitter in IP packet transmission in a Diffserv network having ingress and egress Border Routers and using premium service, expedited forwarding and source route option, recognize incoming packets which have firm jitter requirements. The program verifies

Jitter reduction in Differentiated Services (Diffserv) networks

NARCIS (Netherlands)

Karagiannis, Georgios; Rexhepi, Vlora

2005-01-01

A method and a computer program for reducing jitter in IP packet transmission in a Diffserv network having ingress and egress Border Routers and using premium service, expedited forwarding and source route option, recognize incoming packets which have firm jitter requirements. The program verifies

Accessing data transfer reliability for duty cycled mobile wireless sensor network

International Nuclear Information System (INIS)

Shaikh, F.K.

2014-01-01

Mobility in WSNs (Wireless Sensor Networks) introduces significant challenges which do not arise in static WSNs. Reliable data transport is an important aspect of attaining consistency and QoS (Quality of Service) in several applications of MWSNs (Mobile Wireless Sensor Networks). It is important to understand how each of the wireless sensor networking characteristics such as duty cycling, collisions, contention and mobility affects the reliability of data transfer. If reliability is not managed well, the MWSN can suffer from overheads which reduce its applicability in the real world. In this paper, reliability assessment is being studied by deploying MWSN in different indoor and outdoor scenarios with various duty cycles of the motes and speeds of the mobile mote. Results show that the reliability is greatly affected by the duty cycled motes and the mobility using inherent broadcast mechanisms. (author)

IMPROVING THE LOGISTICAL PROCESSES IN CORPORATE SERVICE SYSTEM

Directory of Open Access Journals (Sweden)

Irina MAKAROVA

2016-03-01

Full Text Available The study deals with enhancing the reliability of freight cars by improving the corporate service system. Assessing of the quality of spare parts suppliers is discussed. An algorithm for supplier selection and an evaluation method, based on cluster analysis of indicators of supplier reliability, is proposed. Alternative developments for a service network, in view of expanding of the car fleet powered by natural gas-based fuel have been considered.

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.

Nondestructive examination (NDE) reliability for inservice inspection of light water reactors

International Nuclear Information System (INIS)

Doctor, S.R.; Deffenbaugh, J.D.; Good, M.S.; Green, E.R.; Heasler, P.G.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.

1989-10-01

The Evaluation and Improvement of NDE Reliability for Inservice Inspection of Light Water Reactors (NDE Reliability) Program at the Pacific Northwest Laboratory was established by the Nuclear Regulatory Commission to determine the reliability of current inservice inspection (ISI) techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this program include determining the reliability of ISI performed on the primary systems of commercial light-water reactors (LWRs); using probabilistic fracture mechanics analysis to determine the impact of NDE unreliability on system safety; and evaluating reliability improvement that can be achieved with improved and advanced technology. A final objective is to formulate recommended revisions to ASME Code and Regulatory requirements based on material properties, service conditions, and NDE capabilities and uncertainties. The program scope is limited to ISI of the primary systems including the piping, vessel, and other inspected components. This is a progress report covering the programmatic work from October 1987 through March 1988. 21 refs., 28 figs., 2 tabs

Nondestructive examination (NDE) reliability for inservice inspection of light waters reactors

International Nuclear Information System (INIS)

Doctor, S.R.; Deffenbaugh, J.D.; Good, M.S.; Green, E.R.; Heasler, P.G.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.

1989-11-01

Evaluation and Improvement of NDE Reliability for Inservice Inspection of Light Water Reactors (NDE Reliability) Program at the Pacific Northwest Laboratory was established by the Nuclear Regulatory Commission to determine the reliability of current inservice inspection (ISI) techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this program include determining the reliability of ISI performed on the primary systems of commercial light-water reactors (LWRs); using probabilistic fracture mechanics analysis to determine the impact of NDE unreliability on system safety; and evaluating reliability improvements that can be achieved with improved and advanced technology. A final objective is to formulate recommended revisions to ASME Code and Regulatory requirements, based on material properties, service conditions, and NDE uncertainties. The program scope is limited to ISI of the primary systems including the piping, vessel, and other inspected components. This is a progress report covering the programmatic work from April 1988 through September 1988. 33 refs., 70 figs., 12 tabs

Nondestructive Examination (NDE) Reliability for Inservice Inspection of Light Water Reactors

International Nuclear Information System (INIS)

Doctor, S.R.; Diaz, A.A.; Friley, J.R.

1993-09-01

The Evaluation and Improvement of NDE Reliability for Inservice Inspection of Light Water Reactors (NDE Reliability) Program at the Pacific Northwest Laboratory was established by the Nuclear Regulatory Commission to determine the reliability of current inservice inspection (ISI) techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this program include determining the reliability of ISI performed on the primary systems of commercial light-water reactors (LWRs); using probabilistic fracture mechanics analysis to determine the impact of NDE unreliability on system safety; and evaluating reliability improvements that can be achieved with improved and advanced technology. A final objective is to formulate recommended revisions to ASME Code and Regulatory requirements, based on material properties, service conditions, and NDE uncertainties. The program scope is limited to ISI of the primary systems including the piping, vessel, and other components inspected in accordance with Section XI of the ASME Code. This is a progress report covering the programmatic work from October 1991 through March 1992

RELIABLE DYNAMIC SOURCE ROUTING PROTOCOL (RDSRP FOR ENERGY HARVESTING WIRELESS SENSOR NETWORKS

Directory of Open Access Journals (Sweden)

B. Narasimhan

2015-03-01

Full Text Available Wireless sensor networks (WSNs carry noteworthy pros over traditional communication. Though, unkind and composite environments fake great challenges in the reliability of WSN communications. It is more vital to develop a reliable unipath dynamic source routing protocol (RDSRPl for WSN to provide better quality of service (QoS in energy harvesting wireless sensor networks (EH-WSN. This paper proposes a dynamic source routing approach for attaining the most reliable route in EH-WSNs. Performance evaluation is carried out using NS-2 and throughput and packet delivery ratio are chosen as the metrics.

[Mortality in Mexico. Some considerations on rural-urban differentials].

Science.gov (United States)

Camposortega Cruz, S

1989-01-01

"In this essay, certain aspects related to rural-urban mortality differentials in Mexico are analyzed....[These include] the availability, advantages, and limitations of different sources of information and the disparity of levels and tendencies according to particular indicators of acceptable reliability, especially those deriving from recent demographic surveys conducted in Mexico. The findings confirm an inverse ratio between size of settlement and mortality, and reveal a widening of the differentials over time." (SUMMARY IN ENG) excerpt

Future of Christian health services – an economic perspective

Directory of Open Access Journals (Sweden)

Steffen Flessa

2016-01-01

Full Text Available Although Christian Health Services have a proud history of healing and compassion especially in developing countries, their future is affected by secular changes in the financing and provision of health care services. However, the nature of life as it is evolving in modern society promises a need for the capacity to deal with increasing dynamics, complexity and uncertainty. In these circumstances the potential capacity of Christians in their institutions and churches to provide Unconditional Reliability suggests a new opportunity. The components of Unconditional Reliability and how they affect the portfolio of Christian Health Services is explained. Effective Christian Health Services will require appropriate analysis of their portfolios.

Novel Differential Current Control Strategy Based on a Modified Three-Level SVPWM for Two Parallel-Connected Inverters

DEFF Research Database (Denmark)

Zorig, Abdelmalik; Barkat, Said; Belkheiri, Mohammed

2017-01-01

Recently, parallel inverters have been investigated to provide multilevel characteristics besides their advantage to increase the power system capacity, reliability, and efficiency. However, the issue of differential currents imbalance remains a challenge in parallel inverter operation. The distr......Recently, parallel inverters have been investigated to provide multilevel characteristics besides their advantage to increase the power system capacity, reliability, and efficiency. However, the issue of differential currents imbalance remains a challenge in parallel inverter operation....... The distribution of switching vectors of the resulting multilevel topology has a certain degree of self-differential current balancing properties. Nevertheless, the method alone is not sufficient to maintain balanced differential current in practical applications. This paper proposes a closed-loop differential...... current control method by introducing a control variable adjusting the dwell time of the selected switching vectors and thus maintaining the differential currents balanced without affecting the overall system performance. The control strategy, including distribution of switching sequence, selection...

Reliability of risk-adjusted outcomes for profiling hospital surgical quality.

Science.gov (United States)

Krell, Robert W; Hozain, Ahmed; Kao, Lillian S; Dimick, Justin B

2014-05-01

reliability was lower, and even fewer hospitals met the thresholds for minimum reliability. Most commonly reported outcome measures have low reliability for differentiating hospital performance. This is especially important for clinical registries that sample rather than collect 100% of cases, which can limit hospital case accrual. Eliminating sampling to achieve the highest possible caseloads, adjusting for reliability, and using advanced modeling strategies (eg, hierarchical modeling) are necessary for clinical registries to increase their benchmarking reliability.

Automated Energy Distribution and Reliability System (AEDR): Final Report

Energy Technology Data Exchange (ETDEWEB)

Buche, D. L.

2008-07-01

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

Service task partition and distribution in star topology computer grid subject to data security constraints

Energy Technology Data Exchange (ETDEWEB)

Xiang Yanping [Collaborative Autonomic Computing Laboratory, School of Computer Science, University of Electronic Science and Technology of China (China); Levitin, Gregory, E-mail: levitin@iec.co.il [Collaborative Autonomic Computing Laboratory, School of Computer Science, University of Electronic Science and Technology of China (China); Israel electric corporation, P. O. Box 10, Haifa 31000 (Israel)

2011-11-15

The paper considers grid computing systems in which the resource management systems (RMS) can divide service tasks into execution blocks (EBs) and send these blocks to different resources. In order to provide a desired level of service reliability the RMS can assign the same blocks to several independent resources for parallel execution. The data security is a crucial issue in distributed computing that affects the execution policy. By the optimal service task partition into the EBs and their distribution among resources, one can achieve the greatest possible service reliability and/or expected performance subject to data security constraints. The paper suggests an algorithm for solving this optimization problem. The algorithm is based on the universal generating function technique and on the evolutionary optimization approach. Illustrative examples are presented. - Highlights: > Grid service with star topology is considered. > An algorithm for evaluating service reliability and data security is presented. > A tradeoff between the service reliability and data security is analyzed. > A procedure for optimal service task partition and distribution is suggested.

Service task partition and distribution in star topology computer grid subject to data security constraints

International Nuclear Information System (INIS)

Xiang Yanping; Levitin, Gregory

2011-01-01

The paper considers grid computing systems in which the resource management systems (RMS) can divide service tasks into execution blocks (EBs) and send these blocks to different resources. In order to provide a desired level of service reliability the RMS can assign the same blocks to several independent resources for parallel execution. The data security is a crucial issue in distributed computing that affects the execution policy. By the optimal service task partition into the EBs and their distribution among resources, one can achieve the greatest possible service reliability and/or expected performance subject to data security constraints. The paper suggests an algorithm for solving this optimization problem. The algorithm is based on the universal generating function technique and on the evolutionary optimization approach. Illustrative examples are presented. - Highlights: → Grid service with star topology is considered. → An algorithm for evaluating service reliability and data security is presented. → A tradeoff between the service reliability and data security is analyzed. → A procedure for optimal service task partition and distribution is suggested.

U.S. Coast Guard (USCG) Maritime Differential GPS (DGPS) Locations

Data.gov (United States)

Department of Homeland Security — NAVCEN operates the Coast Guard Maritime Differential GPS (DGPS) Service and the developing Nationwide DGPS Service (NDGPS), consisting of two control centers and 86...

Reliability of concussion history in former professional football players.

Science.gov (United States)

Kerr, Zachary Y; Marshall, Stephen W; Guskiewicz, Kevin M

2012-03-01

The reliability of athletes to recall and self-report a concussion history has never been quantified. This study examined the reliability of the self-report concussion history measure and explored determinants of recall in the number of self-reported concussions in a group of retired professional football players. In 2001, a short questionnaire was administered to a cohort of former professional football players to ascertain the number of self-reported concussions they sustained during their professional playing careers. In 2010, the same instrument was readministered to a subset (n = 899) of the original cohort to assess reliability. Overall reliability was moderate (weighted Cohen κ = 0.48). The majority (62.1%) reported the same number of concussions in both administrations (2001 and 2010); 31.4% reported more concussions in the second administration. Compared with the "same number reported" group, the "greater number reported" group had more deficits in the second administration in their Short Form 36 physical health (composite score combining physical functioning, role physical, bodily pain, general health) and mental health (e.g., composite score combining vitality, social functioning, role emotional) scales. The self-reported concussion history had moderate reliability in former professional football players, on the basis of two administrations of the same instrument, 9 yr apart. However, changes in health status may be differentially associated with recall of concussions.

Applying the High Reliability Health Care Maturity Model to Assess Hospital Performance: A VA Case Study.

Science.gov (United States)

Sullivan, Jennifer L; Rivard, Peter E; Shin, Marlena H; Rosen, Amy K

2016-09-01

The lack of a tool for categorizing and differentiating hospitals according to their high reliability organization (HRO)-related characteristics has hindered progress toward implementing and sustaining evidence-based HRO practices. Hospitals would benefit both from an understanding of the organizational characteristics that support HRO practices and from knowledge about the steps necessary to achieve HRO status to reduce the risk of harm and improve outcomes. The High Reliability Health Care Maturity (HRHCM) model, a model for health care organizations' achievement of high reliability with zero patient harm, incorporates three major domains critical for promoting HROs-Leadership, Safety Culture, and Robust Process Improvement ®. A study was conducted to examine the content validity of the HRHCM model and evaluate whether it can differentiate hospitals' maturity levels for each of the model's components. Staff perceptions of patient safety at six US Department of Veterans Affairs (VA) hospitals were examined to determine whether all 14 HRHCM components were present and to characterize each hospital's level of organizational maturity. Twelve of the 14 components from the HRHCM model were detected; two additional characteristics emerged that are present in the HRO literature but not represented in the model-teamwork culture and system-focused tools for learning and improvement. Each hospital's level of organizational maturity could be characterized for 9 of the 14 components. The findings suggest the HRHCM model has good content validity and that there is differentiation between hospitals on model components. Additional research is needed to understand how these components can be used to build the infrastructure necessary for reaching high reliability.

A neuro approach to solve fuzzy Riccati differential equations

Energy Technology Data Exchange (ETDEWEB)

Shahrir, Mohammad Shazri, E-mail: mshazri@gmail.com [InstitutSainsMatematik, Universiti Malaya 50603 Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur (Malaysia); Telekom Malaysia, R& D TM Innovation Centre, LingkaranTeknokrat Timur, 63000 Cyberjaya, Selangor (Malaysia); Kumaresan, N., E-mail: drnk2008@gmail.com; Kamali, M. Z. M.; Ratnavelu, Kurunathan [InstitutSainsMatematik, Universiti Malaya 50603 Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur (Malaysia)

2015-10-22

There are many applications of optimal control theory especially in the area of control systems in engineering. In this paper, fuzzy quadratic Riccati differential equation is estimated using neural networks (NN). Previous works have shown reliable results using Runge-Kutta 4th order (RK4). The solution can be achieved by solving the 1st Order Non-linear Differential Equation (ODE) that is found commonly in Riccati differential equation. Research has shown improved results relatively to the RK4 method. It can be said that NN approach shows promising results with the advantage of continuous estimation and improved accuracy that can be produced over RK4.

System reliability as perceived by maintenance personnel on petroleum production facilities

International Nuclear Information System (INIS)

Antonovsky, A.; Pollock, C.; Straker, L.

2016-01-01

The aim of this research was to understand the relationship between maintenance staff perceptions of organisational effectiveness and operational reliability in petroleum operations. Engineering measures exist that assess the effectiveness of maintenance and reliability of equipment. These measures are typically retrospective and may not provide insight into what impedes system reliability. Perceptions of organisational effectiveness by the workforce may provide a predictive measure that could improve our understanding of the human factors that influence system reliability. Maintenance personnel (n=133) from nine petroleum production facilities completed a survey as part of a study of human factors and maintenance reliability. 69 respondents (51.9%) provided comments to an open-ended question in the survey, and these data were analysed using Interpretive Phenomenological Analysis to extract themes. Four super-ordinate themes were identified from the analysis: 1) Communication and access to information, 2) Efficiency of current work systems, 3) Need for better workgroup support, and 4) Management impacts on the workplace. We found a significant relationship between the frequency of the four super-ordinate themes and the facility reliability level as measured by ‘Mean Time Between Failures’: χ"2(6,N=158)=16.2, p=.013. These results demonstrated that operational effectiveness might be differentiated on the basis of survey-derived perceptions of maintenance personnel. - Highlights: • Thematic analysis of survey comments provided insights into workplace reliability • Worker’s comments on reliability related to technical data on time between failures • Management decision-making was the main theme in the lower reliability workplaces • Improving efficiency was the main theme in the higher reliability workplaces • Communication and better workgroup support were themes at all reliability levels

A RELIABILITY TEST USED FOR THE DEVELOPMENT OF A LOYALTY SCALE

Directory of Open Access Journals (Sweden)

Florin-Alexandru LUCA

2017-06-01

Full Text Available The development of a loyalty model involves the construction of a proper research instrument. For the loyalty model of the clients for financial services, the pre-testing of the research questionnaire represents a significant stage. This article presents the methodology used in this stage for testing the reliability of a loyalty scale. Firstly, this implies choosing the appropriate scales for each variable included in the suggested research model. Secondly, the internal consistency for each of these scales is measured as an indicator of their reliability. The reliability analysis described represents an essential stage in building a measurement instrument for a loyalty model.

Relationships Between Service Personal Values, Service Value, Satisfaction, and Loyalty: A Study Regarding Services of Private and State Hospitals in Turkey

Directory of Open Access Journals (Sweden)

Metin Argan

2017-06-01

Full Text Available Service and value are the two inseparable concepts in experiential service environment. Service personal value is a concept that is subjectively assessed from a consumer perspective, and is associated with service value, consumer satisfaction and loyalty. In this context, the purpose of this study was to examine the relationships between services personal values, service value, satisfaction, and loyalty. Data were collected from persons (996 receiving services from private hospitals and state hospitals using convenience sampling method. The scales of service personal values, service value, satisfaction and loyalty were adapted from literature. Confirmatory factor analysis (CFA was used to investigate validity and reliability of the scales. Then, a structural equation model (SEM was developed and tested using data with Lisrel 8.80 software. The results of the study indicate significant relationships between services personal values, service value, satisfaction, and loyalty. The results of the study have significant implications as to how well private hospital managers design strategies of health service, satisfaction, and loyalty.

FRAMATOME nuclear services

International Nuclear Information System (INIS)

Delorme, H.; Buttin, J.

1985-05-01

FRAMATOME is a French company whose main activities since 1958 have been the design and manufacture of standardized PWR Nuclear Steam Supply Systems. FRAMATOME builds the Reactor Coolant System components and installs and starts-up the extended Nuclear Steam Supply Systems. In addition to the supply of spare parts of tooling, the services offered by Framatome are implementation of backfits aimed at performance and safety improvement and equipment reliability, technical assistance and, maintenance and repair services

Equilibrium moisture content of wood at different temperature/moisture conditions in the cladding of wooden constructions and in the relation to their reliability and service life

OpenAIRE

Zdeňka Havířová; Pavel Kubů

2010-01-01

One of the natural properties of wood and wood-based materials is their soaking capacity (hy­gro­sco­pi­ci­ty). The moisture content of wood and building constructions of wood and wood based materials significantly influences the service life and reliability of these constructions and buildings. The equilibrium weight moisture content of built-in wood corresponding to temperature/moisture conditions inside the cladding has therefore a decisive influence on the basic requirements placed on bui...

Reliability Analysis of Operation for Cableways by FTA (Fault Tree Analysis Method

Directory of Open Access Journals (Sweden)

Sergej Težak

2010-05-01

Full Text Available This paper examines the reliability of the operation of cableway systems in Slovenia, which has major impact on the quality of service in the mountain tourism, mainly in wintertime. Different types of cableway installations in Slovenia were captured in a sample and fault tree analysis (FTA was made on the basis of the obtained data. The paper presents the results of the analysis. With these results it is possible to determine the probability of faults of different types of cableways, which types of faults have the greatest impact on the termination of operation, which components of cableways fail most, what is the impact of age of cableways on the occurrence of the faults. Finally, an attempt was made to find if occurrence of faults on individual cableway installation has also impact on traffic on this cableway due to reduced quality of service. KEYWORDS: cableways, aerial ropeways, chairlifts, ski-tows, quality, faults, fault tree analysis, reliability, service quality, winter tourism, mountain tourist centre

Logical Lego? Co-constructed perspectives on service design

NARCIS (Netherlands)

Heath, Claude P.; Coles-Kemp, Lizzie; Hall, Peter A.

2014-01-01

In the era of ‘digital by default’, internet-borne services reach out into spaces and places. One example of such a service is home-based micro-payments using Internet Protocol Television (IPTV) that depends on reliable information-sharing practices between user and service providers. Traditional

Service Engineering as an Approach to Designing Industrial Product Service Systems

OpenAIRE

Schuh, G.; Gudergan, G.

2009-01-01

Organised by: Cranfield University Unique customer solutions which integrate products and services into a high value offering have the potential to successfully differentiate from competition even prices are dictating product markets. However, companies face tremendous challenges to develop customer solutions. Service engineering is considered to be the scientific discipline which supports the design task of intangible offerings and thus a foundation for solution design. We enh...

Determinants of customer satisfaction with professional services: A study of consultants services

DEFF Research Database (Denmark)

Sonne, Anne-Mette

1999-01-01

Although models of service quality and customer satisfaction have been well researched within the consumer goods and services area, much less attention has been paid to high involvement business-to-business service satisfaction. The objective of this study is to contribute to this stream...... of research through a survey of customers of the Norwegian Institute of Fisheries and Aquaculture. Information on which factors are the determinants of customer satisfaction is important to consultants since customer satisfaction is what the service business depends on for repeat business. In this study we...... found that customer satisfaction is mostly influenced by the perceived competence of the consultant and the technical reliability demonstrated in the project. However, the perceived service quality is also influenced by the way the customer is treated during the service production process....

ARCHITECTURE AND RELIABILITY OF OPERATING SYSTEMS

Directory of Open Access Journals (Sweden)

Stanislav V. Nazarov

2018-03-01

Full Text Available Progress in the production technology of microprocessors significantly increased reliability and performance of the computer systems hardware. It cannot be told about the corresponding characteristics of the software and its basis – the operating system (OS. Some achievements of program engineering are more modest in this field. Both directions of OS improvement (increasing of productivity and reliability are connected with the development of effective structures of these systems. OS functional complexity leads to the multiplicity of the structure, which is further enhanced by the specialization of the operating system depending on scope of computer system (complex scientific calculations, real time, information retrieval systems, systems of the automated and automatic control, etc. The functional complexity of the OS leads to the complexity of its architecture, which is further enhanced by the specialization of the operating system, depending on the computer system application area (complex scientific calculations, real-time, information retrieval systems, automated and automatic control systems, etc.. That fact led to variety of modern OS. It is possible to estimate reliability of different OS structures only as results of long-term field experiment or simulation modeling. However it is most often unacceptable because of time and funds expenses for carrying out such research. This survey attempts to evaluate the reliability of two main OS architectures: large multi-layered modular core and a multiserver (client-server system. Represented by continuous Markov chains which are explored in the stationary mode on the basis of transition from systems of the differential equations of Kolmogorov to system of the linear algebraic equations, models of these systems are developed.

Reliability of self-rated tinnitus distress and association with psychological symptom patterns.

Science.gov (United States)

Hiller, W; Goebel, G; Rief, W

1994-05-01

Psychological complaints were investigated in two samples of 60 and 138 in-patients suffering from chronic tinnitus. We administered the Tinnitus Questionnaire (TQ), a 52-item self-rating scale which differentiates between dimensions of emotional and cognitive distress, intrusiveness, auditory perceptual difficulties, sleep disturbances and somatic complaints. The test-retest reliability was .94 for the TQ global score and between .86 and .93 for subscales. Three independent analyses were conducted to estimate the split-half reliability (internal consistency) which was only slightly lower than the test-retest values for scales with a relatively small number of items. Reliability was sufficient also on the level of single items. Low correlation between the TQ and the Hopkins Symptom Checklist (SCL-90-R) indicate a distinct quality of tinnitus-related and general psychological disturbances.

Value of ecosystem hydropower service and its impact on the payment for ecosystem services.

Science.gov (United States)

Fu, B; Wang, Y K; Xu, P; Yan, K; Li, M

2014-02-15

Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29 Euro/hm(2) on the average, of which the high-value area with more than 475.65 Euro/hm(2) is about 750.37 km(2), accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation. Copyright © 2013 Elsevier B.V. All rights reserved.

Performance Evaluation of Cloud Service Considering Fault Recovery

Science.gov (United States)

Yang, Bo; Tan, Feng; Dai, Yuan-Shun; Guo, Suchang

In cloud computing, cloud service performance is an important issue. To improve cloud service reliability, fault recovery may be used. However, the use of fault recovery could have impact on the performance of cloud service. In this paper, we conduct a preliminary study on this issue. Cloud service performance is quantified by service response time, whose probability density function as well as the mean is derived.

Differential Diagnosis of Primary and Secondary Hyperparathyroidism Caused by Vitamin D Deficiency

Directory of Open Access Journals (Sweden)

S.M. Cherenko

2015-08-01

Conclusions. Short ergocalciferol treatment can be a valuable and reliable clinical method to differentiate isolated vitamin D deficiency and asymptomatic primary hyperparathyroidism combined with a lack of vitamin D.

The National Centre of Systems Reliability and some aspects of its future activities

International Nuclear Information System (INIS)

Bourne, A.J.

1975-01-01

The National Centre of Systems Reliability (NCSR) has been set up to enhance the work of the Systems Reliability Service (SRS), which during its four years of operation by the UKAEA has offered to industry expertise in the quantification of reliability of systems in various technological applications. An outline is presented of the background to the establishment of the NCSR, including a brief summary of the work of the SRS. Certain aspects of the future activities of the NCSR particularly in relation to research and collaboration with universities are discussed. (U.K.)

Nondestructive Examination (NDE) Reliability for Inservice Inspection of Light Water Reactors

International Nuclear Information System (INIS)

Doctor, S.R.; Diaz, A.A.; Friley, J.R.; Good, M.S.; Greenwood, M.S.; Heasler, P.G.; Hockey, R.L.; Kurtz, R.J.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.; Vo, T.V.

1992-07-01

The Evaluation and Improvement of NDE Reliability for Inservice Inspection of Light Water Reactors (NDE Reliability) Program at the Pacific Northwest Laboratory was established by the Nuclear Regulatory Commission to determine the reliability of current inservice inspection (ISI) techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this program include determining the reliability of ISI performed on the primary systems of commercial light-water reactors (LWR's); using probabilistic fracture mechanics analysis to determine the impact of NDE unreliability on system safety; and evaluating reliability improvements that can be achieved with improved and advanced technology. A final objective is to formulate recommended revisions to the Regulatory and ASME Code requirements, based on material properties, service conditions, and NDE uncertainties. The program scope is limited to ISI of the primary systems including the piping, vessel, and other components inspected in accordance with Section XI of the ASME Code. This is a progress report covering the programmatic work from April 1991 through September 1991

Nondestructive Examination (NDE) Reliability for Inservice Inspection of Light Water Reactors

International Nuclear Information System (INIS)

Doctor, S.R.; Diaz, A.A.; Friley, J.R.; Greenwood, M.S.; Heasler, P.G.; Kurtz, R.J.; Simonen, F.A.; Spanner, J.C.; Vo, T.V.

1993-11-01

The Evaluation and Improvement of NDE Reliability for Inservice inspection of Light Water Reactors (NDE Reliability) Program at the Pacific Northwest Laboratory was established by the Nuclear Regulatory Commission to determine the reliability of current inservice inspection (ISI) techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this program include determining the reliability of ISI performed on the primary systems of commercial light-water reactors (LWRs);using probabilistic fracture mechanics analysis to determine the impact of NDE unreliability on system safety; and evaluating reliability improvements that can be achieved with improved and advanced technology. A final objective is to formulate recommended revisions to the Regulatory and ASME Code requirements, based on material properties, service conditions, and NDE uncertainties. The program scope is limited to ISI of the primary systems including the piping, vessel and other components inspected in accordance with Section XI of the ASME Code. This is a programs report covering the programmatic work from April 1992 through September 1992

Nondestructive examination (NDE) reliability for inservice inspection of light water reactors

International Nuclear Information System (INIS)

Doctor, S.R.; Good, M.S.; Green, E.R.; Heasler, P.G.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.; Vo, T.V.

1991-08-01

The Evaluation and Improvement of NDE Reliability for Inservice Inspection of Light Water Reactors (NDE Reliability) Program at the Pacific Northwest Laboratory was established by the Nuclear Regulatory Commission to determine the reliability of current inservice inspection (ISI) techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this program include determining the reliability of ISI performed on the primary systems of commercial light-water reactors (LWRs); using probabilistic fracture mechanics analysis to determine the impact of NDE unreliability on system safety; and evaluating reliability improvements that can be achieved with improved and advanced technology. A final objective is to formulate recommended revisions to ASME Code and Regulatory requirements, based on material properties, service conditions, and NDE uncertainties. The program scope is limited to ISI of the primary systems including the piping, vessel, and other components inspected in accordance with Section 6 of the ASME Code. This is a progress report covering the pro grammatic work from April 1989 through September 1989. 12 refs., 4 figs. 5 tabs

Modeling of system reliability Petri nets with aging tokens

International Nuclear Information System (INIS)

Volovoi, V.

2004-01-01

The paper addresses the dynamic modeling of degrading and repairable complex systems. Emphasis is placed on the convenience of modeling for the end user, with special attention being paid to the modeling part of a problem, which is considered to be decoupled from the choice of solution algorithms. Depending on the nature of the problem, these solution algorithms can include discrete event simulation or numerical solution of the differential equations that govern underlying stochastic processes. Such modularity allows a focus on the needs of system reliability modeling and tailoring of the modeling formalism accordingly. To this end, several salient features are chosen from the multitude of existing extensions of Petri nets, and a new concept of aging tokens (tokens with memory) is introduced. The resulting framework provides for flexible and transparent graphical modeling with excellent representational power that is particularly suited for system reliability modeling with non-exponentially distributed firing times. The new framework is compared with existing Petri-net approaches and other system reliability modeling techniques such as reliability block diagrams and fault trees. The relative differences are emphasized and illustrated with several examples, including modeling of load sharing, imperfect repair of pooled items, multiphase missions, and damage-tolerant maintenance. Finally, a simple implementation of the framework using discrete event simulation is described

Evaluating the service quality of third-party logistics service providers using the analytic hierarchy process

Directory of Open Access Journals (Sweden)

Soon-hoo So

2006-12-01

Full Text Available In this study we apply the analytic hierarchy process (AHP to evaluate the service quality of third-party logistics (3PL service providers. We first conceptualize five dimensions of 3PL service quality (i.e. tangibles, reliability, responsiveness, assurance and empathy. We then apply the AHP method to determine the relative weights of the five service quality dimensions and eventually select the best 3PL service provider. To implement this idea in practice, we conduct an empirical case study on four companies providing 3PL services in Korea. The results indicate that Responsiveness out of the five service quality dimensions is the most important factor in the perception of 3PL customers.

Problems in diagnosing and forecasting power equipment reliability

Energy Technology Data Exchange (ETDEWEB)

Popkov, V I; Demirchyan, K S

1979-11-01

This general survey deals with approaches to the resolution of such problems as the gathering, analysis and systematization of data on component defects in power equipment and setting up feedback with the manufacturing plants and planning organizations to improve equipment reliability. Such efforts on the part of designers, manufacturers and operating and repair organizations in analyzing faults in 300 MW turbogenerators during 1974-1977 reduced the specific fault rate by 20 to 25% and the downtime per failure by 35 to 40%. Since power equipment should operate for several hundreds of thousands of hours (20 to 30 years) and the majority of power components have guaranteed service lives of no more than 10/sup 5/ hours, an extremely difficult problem is the determination of the reliability of equipment past the 10/sup 5/ point. The present trend in the USSR Unified Power System towards increasing the number of shutdowns and startups, which in the case of turbogenerators of up 1200 MW power can reach 7500 to 10,000 cycles is noted. Other areas briefly treated are: MHD generator reliability and economy; nuclear power plant reliability and safety; the reliability of high-power high-voltage thyristor converters; the difficulties involved in scale modeling of power system reliability and the high cost of the requisite full-scale studies; the poor understanding of long term corrosion and erosion processes. The review concludes with arguments in favor of greater computerization of all aspects of power system management.

Mammography image assessment; validity and reliability of current scheme

International Nuclear Information System (INIS)

Hill, C.; Robinson, L.

2015-01-01

Mammographers currently score their own images according to criteria set out by Regional Quality Assurance. The criteria used are based on the ‘Perfect, Good, Moderate, Inadequate’ (PGMI) marking criteria established by the National Health Service Breast Screening Programme (NHSBSP) in their Quality Assurance Guidelines of 2006 1 . This document discusses the validity and reliability of the current mammography image assessment scheme. Commencing with a critical review of the literature this document sets out to highlight problems with the national approach to the use of marking schemes. The findings suggest that ‘PGMI’ scheme is flawed in terms of reliability and validity and is not universally applied across the UK. There also appear to be differences in schemes used by trainees and qualified mammographers. Initial recommendations are to be made in collaboration with colleagues within the National Health Service Breast Screening Programme (NHSBSP), Higher Education Centres, College of Radiographers and the Royal College of Radiologists in order to identify a mammography image appraisal scheme that is fit for purpose. - Highlights: • Currently no robust evidence based marking tools in use for the assessment of images in mammography. • Is current system valid, reliable and robust? • How can the current image assessment tool be improved? • Should students and qualified mammographers use the same tool? • What marking criteria are available for image assessment?

The impact of reliability centered maintenance on plant prospects for license renewal

International Nuclear Information System (INIS)

Elliott, J.O.; Nakahara, Y.

1991-01-01

Much attention has been directed in recent years to means of extending nuclear power plant life. As many plants enter their third decade of service, the questions loom large of how to keep aging plants reliable, as well as how to assure reliability and safety to an extent sufficient to warrant license renewal at the end of the current licensing term. Concurrently the nuclear industry has seen a growing interest in reducing the cost and complexity of maintenance activities while at the same time improving plant reliability and availability. Attainment of these seemingly contradictory aims is being aided by the introduction of a maintenance philosophy developed originally by the airline industry and subsequently applied with great success both in that industry and the U.S. military services. Reliability Centered Maintenance (RCM), in its basic form, may be described as a consideration of reliability and maintenance problems from a systems level approach, allowing a focus on preservation of system functions as the aim of a maintenance program optimized for both safety and economics. It is this systematic view of plant maintenance, with the emphasis on preservation of overall functions rather than individual parts and components which sets RCM apart from past nuclear plant maintenance philosophies. It is also the factor which makes application of RCM an ideal first step in development of strategies for life extension and license renewal, both for aging plants, and for plants just beginning their first license term

Skilled delivery care service utilization in Ethiopia: analysis of rural-urban differentials based on national demographic and health survey (DHS) data.

Science.gov (United States)

Fekadu, Melaku; Regassa, Nigatu

2014-12-01

Despite the slight progress made on Antenatal Care (ANC) utilization, skilled delivery care service utilization in Ethiopia is still far-below any acceptable standards. Only 10% of women receive assistance from skilled birth attendants either at home or at health institutions, and as a result the country is recording a high maternal mortality ratio (MMR) of 676 per 100,000 live births (EDHS, 2011). Hence, this study aimed at identifying the rural-urban differentials in the predictors of skilled delivery care service utilization in Ethiopia. The study used the recent Ethiopian Demographic and Health Survey (EDHS 2011) data. Women who had at least one birth in the five years preceding the survey were included in this study. The data were analyzed using univariate (percentage), bivariate (chi-square) and multivariate (Bayesian logistic regression). The results showed that of the total 6,641 women, only 15.6% received skilled delivery care services either at home or at health institution. Rural women were at greater disadvantage to receive the service. Only 4.5% women in rural areas received assistance from skilled birth attendants (SBAs) compared to 64.1 % of their urban counter parts. Through Bayesian logistic regression analysis, place of residence, ANC utilization, women's education, age and birth order were identified as key predictors of service utilization. The findings highlight the need for coordinated effort from government and stakeholders to improve women's education, as well as strengthen community participation. Furthermore, the study recommended the need to scale up the quality of ANC and family planning services backed by improved and equitable access, availability and quality of skilled delivery care services.

Applying franchising principles to improving water and sanitation services reliability

CSIR Research Space (South Africa)

Wall, K

2008-11-01

Full Text Available CSIR research has found that franchising partnerships could alleviate and address many challenges in the operation and maintenance of water services infrastructure. Franchising brings appropriate training to those on-site, and also offers backup off...

Measuring service quality and its relationship to future consumer behavior.

Science.gov (United States)

Headley, D E; Miller, S J

1993-01-01

The authors adapt the SERVQUAL scale for medical care services and examine it for reliability, dimensionality, and validity in a primary care clinic setting. In addition, they explore the possibility of a link between perceived service quality--and its various dimensions--and a patient's future intent to complain, compliment, repeat purchase, and switch providers. Findings from 159 matched-pair responses indicate that the SERVQUAL scale can be adapted reliably to a clinic setting and that the dimensions of reliability, dependability, and empathy are most predictive of a patient's intent to complain, compliment, repeat purchase, and switch providers.

Business Cases for Microgrids: Modeling Interactions of Technology Choice, Reliability, Cost, and Benefit

Science.gov (United States)

Hanna, Ryan

Distributed energy resources (DERs), and increasingly microgrids, are becoming an integral part of modern distribution systems. Interest in microgrids--which are insular and autonomous power networks embedded within the bulk grid--stems largely from the vast array of flexibilities and benefits they can offer stakeholders. Managed well, they can improve grid reliability and resiliency, increase end-use energy efficiency by coupling electric and thermal loads, reduce transmission losses by generating power locally, and may reduce system-wide emissions, among many others. Whether these public benefits are realized, however, depends on whether private firms see a "business case", or private value, in investing. To this end, firms need models that evaluate costs, benefits, risks, and assumptions that underlie decisions to invest. The objectives of this dissertation are to assess the business case for microgrids that provide what industry analysts forecast as two primary drivers of market growth--that of providing energy services (similar to an electric utility) as well as reliability service to customers within. Prototypical first adopters are modeled--using an existing model to analyze energy services and a new model that couples that analysis with one of reliability--to explore interactions between technology choice, reliability, costs, and benefits. The new model has a bi-level hierarchy; it uses heuristic optimization to select and size DERs and analytical optimization to schedule them. It further embeds Monte Carlo simulation to evaluate reliability as well as regression models for customer damage functions to monetize reliability. It provides least-cost microgrid configurations for utility customers who seek to reduce interruption and operating costs. Lastly, the model is used to explore the impact of such adoption on system-wide greenhouse gas emissions in California. Results indicate that there are, at present, co-benefits for emissions reductions when customers

Global On-Chip Differential Interconnects with Optimally-Placed Twists

NARCIS (Netherlands)

Mensink, E.; Schinkel, Daniel; Klumperink, Eric A.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

2005-01-01

Global on-chip communication is receiving quite some attention as global interconnects are rapidly becoming a speed, power and reliability bottleneck for digital CMOS systems. Recently, we proposed a bus-transceiver test chip in 0.13 μm CMOS using 10 mm long uninterrupted differential interconnects

Approximate Solutions of Nonlinear Partial Differential Equations by Modified q-Homotopy Analysis Method

Directory of Open Access Journals (Sweden)

Shaheed N. Huseen

2013-01-01

Full Text Available A modified q-homotopy analysis method (mq-HAM was proposed for solving nth-order nonlinear differential equations. This method improves the convergence of the series solution in the nHAM which was proposed in (see Hassan and El-Tawil 2011, 2012. The proposed method provides an approximate solution by rewriting the nth-order nonlinear differential equation in the form of n first-order differential equations. The solution of these n differential equations is obtained as a power series solution. This scheme is tested on two nonlinear exactly solvable differential equations. The results demonstrate the reliability and efficiency of the algorithm developed.

Ecosystem services for energy security

Energy Technology Data Exchange (ETDEWEB)

Athanas, Andrea; McCormick, Nadine

2010-09-15

The world is at an energy crossroads. The changes underway will have implications for ecosystems and livelihoods. Energy security is the reliable supply of affordable energy, of which there are two dimensions; reliability and resilience. Changes in ecosystem services linked to degradation and climate change have the potential to impact both on the reliabiity of energy systems and on their resiliance. Investing in ecosystems can help safeguard energy systems, and mitigate unforeseen risks to energy security. The energy and conservation community should come together to build reliable and resilliant energy systems in ways which recognise and value supporting ecosystems.

Non-utility generation and demand management reliability of customer delivery systems

International Nuclear Information System (INIS)

Hamoud, G.A.; Wang, L.

1995-01-01

A probabilistic methodology for evaluating the impact of non-utility generation (NUG) and demand management programs (DMP) on supply reliability of customer delivery systems was presented. The proposed method was based on the criteria that the supply reliability to the customers on the delivery system should not be affected by the integration of either NUG or DMPs. The method considered station load profile, load forecast, and uncertainty in size and availability of the nuio. Impacts on system reliability were expressed in terms of possible delays of the in-service date for new facilities or in terms of an increase in the system load carrying capability. Examples to illustrate the proposed methodology were provided. 10 refs., 8 tabs., 2 figs

Electrical system design and reliability at Ontario Hydro nuclear generating stations

Energy Technology Data Exchange (ETDEWEB)

Royce, C. J. [Ontario Hydro, 700 University Avenue, Toronto, Ontario M5G 1X6 (Canada)

1986-02-15

This paper provides an overview of design practice and the predicted and actual reliability of electrical station service Systems at Ontario Nuclear Generating Stations. Operational experience and licensing changes have indicated the desirability of improving reliability in certain instances. For example, the requirement to start large emergency coolant injection pumps resulted in the turbine generator units in a multi-unit station being used as a back-up power supply. Results of reliability analyses are discussed. To mitigate the effects of common mode events Ontario Hydro adopted a 'two group' approach to the design of safety related Systems. This 'two group' approach is reviewed and a single fully environmentally qualified standby power supply is proposed for future use. (author)

Reliability of optical fibres and components final report of COST 246

CERN Document Server

Griffioen, Willem; Gadonna, Michel; Limberger, Hans; Heens, Bernard; Knuuttila, Hanna; Kurkjian, Charles; Mirza, Shehzad; Opacic, Aleksandar; Regio, Paola; Semjonov, Sergei

1999-01-01

Reliability of Optical Fibres and Components reports the findings of COST 246 (1993-1998) - European research initiative in the field of optical telecommunications. Experts in the materials and reliability field of optical fibres and components have contributed to this unique study programme. The results, conclusions and achievements of their work have been obtained through joint experimentation and discussion with representatives from manufacturing and research groups. Topics covered include: Lifetime estimation; Failure mechanisms; Ageing test methods; Field data and service environments for components. For the first time the reader can explore the reliability of products and examine the results and conclusions in published form. This comprehensive volume is intended to provide a deeper understanding of the reliability of optical fibres and components. The book will be extremely useful to all scientists and practitioners involved in the industry.

Cloud-based Collaborative Business Services Provision

NARCIS (Netherlands)

Camarinha-Matos, L.M.; Afsarmanesh, H.; Oliveira, A.I.; Ferrada, F.; Hammoudi, S.; Cordeiro, J.; Maciaszek, L.A.; Filipe, J.

2014-01-01

The notion of service-enhanced product, representing the association of services to manufactured products, offers an important mechanism for value creation and product differentiation. This is particularly relevant in the case of complex, highly customized and long-life products. Provision of

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

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

Bring Your Own Device - Providing Reliable Model of Data Access

Directory of Open Access Journals (Sweden)

Stąpór Paweł

2016-10-01

Full Text Available The article presents a model of Bring Your Own Device (BYOD as a model network, which provides the user reliable access to network resources. BYOD is a model dynamically developing, which can be applied in many areas. Research network has been launched in order to carry out the test, in which as a service of BYOD model Work Folders service was used. This service allows the user to synchronize files between the device and the server. An access to the network is completed through the wireless communication by the 802.11n standard. Obtained results are shown and analyzed in this article.

Reliability-Oriented Design and Analysis of Input Capacitors in Single-Phase Transformer-less Photovoltaic Inverters

DEFF Research Database (Denmark)

Wang, Huai; Yang, Yongheng; Blaabjerg, Frede

2013-01-01

While 99% efficiency has been reported, the target of 20 years of service time imposes new challenge to cost-effective solutions for grid-connected photovoltaic (PV) inverters. Aluminum electrolytic capacitors are the weak-link in terms of reliability and lifetime in single-phase PV systems....... A reliability-oriented design guideline is proposed in this paper for the input capacitors in single-phase transformer-less PV inverters. The guideline ensures that the service time requirement is to be accomplished under different power levels and ambient temperature profiles. The theoretical analysis has been...... demonstrated by a 1 kW single-phase PV inverter....

Differentiation, context and teacher education: the changing profile of trainees on in-service initial teacher training programmes in the lifelong learning sector

Directory of Open Access Journals (Sweden)

Noel, Penny

2009-01-01

Full Text Available Analysis of initial teacher training (ITT student data relating to the University of Huddersfield part-time in-service Cert Ed/PGCE over a three-year period has revealed significant change in the make-up of trainee cohorts. There has been an increase in younger trainees and in trainees very new to teaching, although more experienced and older trainees do continue to enrol. There has also been a considerable shift in the balance of trainees away from further education (FE college staff. These changes have implications for those who manage and deliver teacher education for the sector. It remains of key importance that the curriculum is not experienced as overly ‘FE-college centric’ and that mentoring arrangements acknowledge the needs of trainees from diverse contexts. It is clear that in the delivery of ITT for the lifelong learning sector, increasingly, one size will not comfortably fit all. Within teacher education much emphasis is placed upon the role of differentiation in regard to trainee practice. The changing trainee profile identified requires that teacher education itself unambiguously models a differentiated approach – and, in relation to teacher education for the lifelong learning sector, differentiation must address workplace context.

Evaluation of Network Reliability for Computer Networks with Multiple Sources

Directory of Open Access Journals (Sweden)

Yi-Kuei Lin

2012-01-01

Full Text Available Evaluating the reliability of a network with multiple sources to multiple sinks is a critical issue from the perspective of quality management. Due to the unrealistic definition of paths of network models in previous literature, existing models are not appropriate for real-world computer networks such as the Taiwan Advanced Research and Education Network (TWAREN. This paper proposes a modified stochastic-flow network model to evaluate the network reliability of a practical computer network with multiple sources where data is transmitted through several light paths (LPs. Network reliability is defined as being the probability of delivering a specified amount of data from the sources to the sink. It is taken as a performance index to measure the service level of TWAREN. This paper studies the network reliability of the international portion of TWAREN from two sources (Taipei and Hsinchu to one sink (New York that goes through a submarine and land surface cable between Taiwan and the United States.

Service workload patterns for QoS-driven cloud resource management

OpenAIRE

Zhang, Li; Zhang, Yichuan; Jamshidi, Pooyan; Xu, Lei; Pahl, Claus

2015-01-01

Cloud service providers negotiate SLAs for customer services they offer based on the reliability of performance and availability of their lower-level platform infrastructure. While availability management is more mature, performance management is less reliable. In order to support a continuous approach that supports the initial static infrastructure configuration as well as dynamic reconfiguration and auto-scaling, an accurate and efficient solution is required. We propose a prediction techni...

Nanotopographical Control of Stem Cell Differentiation

Directory of Open Access Journals (Sweden)

Laura E. McNamara

2010-01-01

Full Text Available Stem cells have the capacity to differentiate into various lineages, and the ability to reliably direct stem cell fate determination would have tremendous potential for basic research and clinical therapy. Nanotopography provides a useful tool for guiding differentiation, as the features are more durable than surface chemistry and can be modified in size and shape to suit the desired application. In this paper, nanotopography is examined as a means to guide differentiation, and its application is described in the context of different subsets of stem cells, with a particular focus on skeletal (mesenchymal stem cells. To address the mechanistic basis underlying the topographical effects on stem cells, the likely contributions of indirect (biochemical signal-mediated and direct (force-mediated mechanotransduction are discussed. Data from proteomic research is also outlined in relation to topography-mediated fate determination, as this approach provides insight into the global molecular changes at the level of the functional effectors.

On Quality of Service Management

National Research Council Canada - National Science Library

Lee, Chen

1999-01-01

A quality of service (QoS) management framework for systems is presented that satisfies application needs along multiple dimensions such as timeliness, reliability, cryptographic security and other application specific quality requirements...

Mapping ecosystem services in the St. Louis River Estuary

Science.gov (United States)

Sustainable management of ecosystems for the perpetual flow of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching U.S. EPA goal of ...

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

Innovating the differential pressure switch

International Nuclear Information System (INIS)

Ostrelich, M.

2010-01-01

When Barton Jones filed for patent 2, 400, 048 in 1943 for his liquid filled dual-bellows differential pressure unit, he initiated an engineering concept that has endured and has been validated for rugged, reliable and accurate measurement and control. Although based on established engineering principles the execution of the concept to instrumentation products has resisted innovation until present time. With the objective of preserving the established engineering principles and maintaining the same form fit and function of the original instrumentation, it was necessary to apply present day component availability and manufacturing techniques to construct instrumentation that has improved reliability and facilitates assembly and calibration. The original component design is presented and is compared with the improved equivalent. The application of this instrumentation utilized for the control of Nuclear Power Plants has provided the initiative for component innovation. (authors)

Linking employee perceptions of collective efficacy in self-managing service teams with customer-perceived service quality : a psychometric assessment

NARCIS (Netherlands)

Jong, de A.; Wetzels, M.G.M.; Ruyter, de J.C.

2008-01-01

Purpose – The purpose of this paper is to investigate the linkage between self-managing team (SMT) member perceptions of collective efficacy and customer-perceived service quality, and the most cost-efficient way to reliably assess collective efficacy and customer-perceived service quality, using

Multi-state reliability for coolant pump based on dependent competitive failure model

International Nuclear Information System (INIS)

Shang Yanlong; Cai Qi; Zhao Xinwen; Chen Ling

2013-01-01

By taking into account the effect of degradation due to internal vibration and external shocks. and based on service environment and degradation mechanism of nuclear power plant coolant pump, a multi-state reliability model of coolant pump was proposed for the system that involves competitive failure process between shocks and degradation. Using this model, degradation state probability and system reliability were obtained under the consideration of internal vibration and external shocks for the degraded coolant pump. It provided an effective method to reliability analysis for coolant pump in nuclear power plant based on operating environment. The results can provide a decision making basis for design changing and maintenance optimization. (authors)

MRI in differentiation between recurrent disk herniation and postoperative scar. Value of FLAIR sequences

International Nuclear Information System (INIS)

Capiel, Carlos A. h; Bouzas, Carlos A.; Porto, Viviana G.

2000-01-01

The differential diagnosis between epidural fibrosis and recurrent or residual disk herniation in symptomatic patients who have been operated is often difficult. The MRI with Spin Echo T1 sequences before and after i.v. gadolinium plays and important role in the differentiation of these two entities. The signal characteristics in T1 and T2 sequences are not reliable to distinguish between herniated disk and scar. In order to evaluate the use of the FLAIR technique in the differentiation between herniated disk and epidural fibrosis we used MRI to study 37 symptomatic patients who had been operated of lumbar disk herniation, with FSE-T2 sequences in axial and sagittal planes, FLAIR in axial sections and SE-T1 in sagittal and axial sections before and after i.v. gadolinium. This sequence was used as gold standard for the final diagnosis. We conclude that the FLAIR technique is a reliable alternative in the differential diagnosis between epidural fibrosis and herniated disk, providing a positive correlation to the SE-T1-weighted images with i.v. gadolinium in 100% of the patients. (author)

75 FR 50853 - Special Conditions: Cirrus Design Corporation Model SF50 Airplane; Function and Reliability Testing

Science.gov (United States)

2010-08-18

... airplanes. 1. Function and Reliability Testing. Flight tests: In place of 14 CFR 21.35(b)(2), the following...; Function and Reliability Testing AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special... to CAR part 3 became effective January 15, 1951, and deleted the service test requirements in Section...

An attempt to use FMEA method for an approximate reliability assessment of machinery

Directory of Open Access Journals (Sweden)

Przystupa Krzysztof

2017-01-01

Full Text Available The paper presents a modified FMEA (Failure Mode and Effect Analysis method to assess reliability of the components that make up a wrench type 2145: MAX Impactol TM Driver Ingersoll Rand Company. This case concerns the analysis of reliability in conditions, when full service data is not known. The aim of the study is to determine the weakest element in the design of the tool.

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 ...

Reliability of structures of industrial installations. Theory and applications of probabilistic mechanics

International Nuclear Information System (INIS)

Procaccia, H.; Morilhat, P.; Carle, R.; Menjon, G.

1996-01-01

The management of the service life of mechanical materials implies an evaluation of their risk of failure during their use. To evaluate this risk the following methods are used: the classical frequency statistics applied to experience feedback data concerning failures noticed during operation of active parts (pumps, valves, exchangers, circuit breakers etc..); the Bayesian approach in the case of scarce statistical data and when experts are needed to compensate the lack of information; the structures reliability approach when no data are available and when a theoretical model of degradation must be used, in particular for passive structures (pressure vessels, pipes, tanks, etc..). The aim of this book is to describe the principles and applications of this third approach to industrial installations. Chapter 1 recalls the historical aspects of the probabilistic approach to the reliability of structures and the existing codes. Chapter 2 presents the level 1 deterministic method applied so far for the conceiving of passive structures. The Cornell reliability index, already used in civil engineering codes, is defined in chapter 3. The Hasofer and Lind reliability index, a generalization of the Cornell index, is defined in chapter 4. Chapter 5 concerns the application of probabilistic approaches to optimization studies with the introduction of the economical variables linked to the risk and the possible actions to limit this risk (in-service inspection, maintenance, repairing etc..). Chapters 6 and 7 describe the Monte Carlo simulation and approximation methods for failure probabilistic calculations, and recall the fracture mechanics basis and the models of load and degradation of industrial installations. Some applications are given in chapter 9 with the cases of the safety margins quantization of a fissured pipe and the optimizing of the in-service inspection policy of a steam generator. Chapter 10 raises the problem of the coupling between mechanical and reliability

effect of uncertainty on the fatigue reliability of reinforced concrete ...

African Journals Online (AJOL)

In this paper, a reliability time-variant fatigue analysis and uncertainty effect on the serviceability of reinforced concrete bridge deck was carried out. A simply supported 15m bridge deck was specifically used for the investigation. Mathematical models were developed and the uncertainties in structural resistance, applied ...

Database reliability engineering designing and operating resilient database systems

CERN Document Server

Campbell, Laine

2018-01-01

The infrastructure-as-code revolution in IT is also affecting database administration. With this practical book, developers, system administrators, and junior to mid-level DBAs will learn how the modern practice of site reliability engineering applies to the craft of database architecture and operations. Authors Laine Campbell and Charity Majors provide a framework for professionals looking to join the ranks of today’s database reliability engineers (DBRE). You’ll begin by exploring core operational concepts that DBREs need to master. Then you’ll examine a wide range of database persistence options, including how to implement key technologies to provide resilient, scalable, and performant data storage and retrieval. With a firm foundation in database reliability engineering, you’ll be ready to dive into the architecture and operations of any modern database. This book covers: Service-level requirements and risk management Building and evolving an architecture for operational visibility ...

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.

Revisiting Frequency Reuse towards Supporting Ultra-Reliable Ubiquitous-Rate Communication

DEFF Research Database (Denmark)

Park, Jihong; Kim, Dong Min; Popovski, Petar

2017-01-01

One of the goals of 5G wireless systems stated by the NGMN alliance is to provide moderate rates (50+ Mbps) everywhere and with very high reliability. We term this service Ultra-Reliable Ubiquitous-Rate Communication (UR2C). This paper investigates the role of frequency reuse in supporting UR2C...... in the downlink. To this end, two frequency reuse schemes are considered: user-specific frequency reuse (FRu) and BS-specific frequency reuse (FRb). For a given unit frequency channel, FRu reduces the number of serving user equipments (UEs), whereas FRb directly decreases the number of interfering base stations...

Improving the reliability of service-water systems at nuclear power plants

International Nuclear Information System (INIS)

Neitzel, D.A.; Johnson, K.I.; Daling, P.M.; Chang, T.Y.

1989-01-01

Fouling and clogging caused by sedimentation, corrosion, and the buildup of biological organisms is a persistent problem whenever raw water from a river, lake, or ocean is used as a heat exchange medium. The fouling caused by raw water cooling of service-water systems at nuclear power plants is a particular concern because of the potential for affecting safety-related heat exchangers and components, including online and redundant backup units. Open-cycle service-water, as discussed here, provide cooling to reactor support systems required during shutdown and emergency conditions and relate to those heat exchangers and components cooled directly by raw water. To resolve this issue, the NRC initiated a research program at the Pacific Northwest Laboratory (PNL), to study the conditions that allow fouling and to compare alternative surveillance and control programs to minimize service water system fouling. There is no single solution to biological, sediment, and corrosion fouling. An effective surveillance and control program must satisfy certain criteria to address major areas of the service-water system and the major fouling types. Three fouling program alternatives were developed. Value/impact (or cost/benefit) studies were performed on these three alternatives. The alternative chosen to be most cost effective is a baseline fouling program. It consists of two principal elements of a control program, continuous chlorination (for example during bivalve spawning seasons) and periodic flushing and flow testing of redundant and infrequently used cooling loops, to minimize flow blockage that would result from biofouling and sediment/corrosion product buildup. In addition, a surveillance program is recommended to regularly inspect the intake structure for macroscopic biological fouling organisms, sediment, and corrosion

Validation of Medical Tourism Service Quality Questionnaire (MTSQQ) for Iranian Hospitals.

Science.gov (United States)

Qolipour, Mohammad; Torabipour, Amin; Khiavi, Farzad Faraji; Malehi, Amal Saki

2017-03-01

Assessing service quality is one of the basic requirements to develop the medical tourism industry. There is no valid and reliable tool to measure service quality of medical tourism. This study aimed to determine the reliability and validity of a Persian version of medical tourism service quality questionnaire for Iranian hospitals. To validate the medical tourism service quality questionnaire (MTSQQ), a cross-sectional study was conducted on 250 Iraqi patients referred to hospitals in Ahvaz (Iran) from 2015. To design a questionnaire and determine its content validity, the Delphi Technique (3 rounds) with the participation of 20 medical tourism experts was used. Construct validity of the questionnaire was assessed through exploratory and confirmatory factor analysis. Reliability was assessed using Cronbach's alpha coefficient. Data were analyzed by Excel 2007, SPSS version18, and Lisrel l8.0 software. The content validity of the questionnaire with CVI=0.775 was confirmed. According to exploratory factor analysis, the MTSQQ included 31 items and 8 dimensions (tangibility, reliability, responsiveness, assurance, empathy, exchange and travel facilities, technical and infrastructure facilities and safety and security). Construct validity of the questionnaire was confirmed, based on the goodness of fit quantities of model (RMSEA=0.032, CFI= 0.98, GFI=0.88). Cronbach's alpha coefficient was 0.837 and 0.919 for expectation and perception questionnaire. The results of the study showed that the medical tourism SERVQUAL questionnaire with 31 items and 8 dimensions was a valid and reliable tool to measure service quality of medical tourism in Iranian hospitals.

Reliability of a structured interview for admission to an emergency medicine residency program.

Science.gov (United States)

Blouin, Danielle

2010-10-01

Interviews are most important in resident selection. Structured interviews are more reliable than unstructured ones. We sought to measure the interrater reliability of a newly designed structured interview during the selection process to an Emergency Medicine residency program. The critical incident technique was used to extract the desired dimensions of performance. The interview tool consisted of 7 clinical scenarios and 1 global rating. Three trained interviewers marked each candidate on all scenarios without discussing candidates' responses. Interitem consistency and estimates of variance were computed. Twenty-eight candidates were interviewed. The generalizability coefficient was 0.67. Removing the central tendency ratings increased the coefficient to 0.74. Coefficients of interitem consistency ranged from 0.64 to 0.74. The structured interview tool provided good although suboptimal interrater reliability. Increasing the number of scenarios improves reliability as does applying differential weights to the rating scale anchors. The latter would also facilitate the identification of those candidates with extreme ratings.

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 ...

Pricing strategies under heterogeneous service requirements

NARCIS (Netherlands)

Mandjes, M.R.H.

This paper analyzes a communication network, used by customers with heterogeneous service requirements. We investigate priority queueing as a way to establish service differentiation. It is assumed that there is an infinite population of customers, who join the network as long as their utility

DIRAC reliable data management for LHCb

CERN Document Server

Smith, A C

2008-01-01

DIRAC, LHCb's Grid Workload and Data Management System, utilizes WLCG resources and middleware components to perform distributed computing tasks satisfying LHCb's Computing Model. The Data Management System (DMS) handles data transfer and data access within LHCb. Its scope ranges from the output of the LHCb Online system to Grid-enabled storage for all data types. It supports metadata for these files in replica and bookkeeping catalogues, allowing dataset selection and localization. The DMS controls the movement of files in a redundant fashion whilst providing utilities for accessing all metadata. To do these tasks effectively the DMS requires complete self integrity between its components and external physical storage. The DMS provides highly redundant management of all LHCb data to leverage available storage resources and to manage transient errors in underlying services. It provides data driven and reliable distribution of files as well as reliable job output upload, utilizing VO Boxes at LHCb Tier1 sites ...

75 FR 29962 - Special Conditions: Cirrus Design Corporation Model SF50 Airplane; Function and Reliability Testing

Science.gov (United States)

2010-05-28

... SF50 airplanes. 1. Function and Reliability Testing Flight tests: In place of 14 CFR part 21.35(b)(2... Reliability Testing AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed special..., 1951, and deleted the service test requirements in Section 3.19 for airplanes of 6,000 pounds maximum...

Strategic bidding of generating units in competitive electricity market with considering their reliability

International Nuclear Information System (INIS)

Soleymani, S.; Ranjbar, A.M.; Shirani, A.R.

2008-01-01

In the restructured power systems, they are typically scheduled based on the offers and bids to buy and sell energy and ancillary services (AS) subject to operational and security constraints. Generally, no account is taken of unit reliability when scheduling it. Therefore generating units have no incentive to improve their reliability. This paper proposes a new method to obtain the equilibrium points for reliability and price bidding strategy of units when the unit reliability is considered in the scheduling problem. The proposed methodology employs the supply function equilibrium (SFE) for modeling a unit's bidding strategy. Units change their bidding strategies and improve their reliability until Nash equilibrium points are obtained. GAMS (general algebraic modeling system) language has been used to solve the market scheduling problem using DICOPT optimization software with mixed integer non-linear programming. (author)

A quantitative calculation for software reliability evaluation

Energy Technology Data Exchange (ETDEWEB)

Lee, Young-Jun; Lee, Jang-Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

To meet these regulatory requirements, the software used in the nuclear safety field has been ensured through the development, validation, safety analysis, and quality assurance activities throughout the entire process life cycle from the planning phase to the installation phase. A variety of activities, such as the quality assurance activities are also required to improve the quality of a software. However, there are limitations to ensure that the quality is improved enough. Therefore, the effort to calculate the reliability of the software continues for a quantitative evaluation instead of a qualitative evaluation. In this paper, we propose a quantitative calculation method for the software to be used for a specific operation of the digital controller in an NPP. After injecting random faults in the internal space of a developed controller and calculating the ability to detect the injected faults using diagnostic software, we can evaluate the software reliability of a digital controller in an NPP. We tried to calculate the software reliability of the controller in an NPP using a new method that differs from a traditional method. It calculates the fault detection coverage after injecting the faults into the software memory space rather than the activity through the life cycle process. We attempt differentiation by creating a new definition of the fault, imitating the software fault using the hardware, and giving a consideration and weights for injection faults.

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

Managing wind turbine reliability and maintenance via performance-based contract

DEFF Research Database (Denmark)

Jin, Tongdan; Ding, Yi; Guo, Huairui

2012-01-01

between system cost, reliability and spare parts stocking. This analytical insight into the system performance allows the turbine manufacturer to optimize design, production, and after-sales services. The study aims to create a theoretical basis to facilitate the transition of the maintenance paradigm......Performance-based contracting (PBC) is reshaping the acquisition, operation, and maintenance of capital equipment. Under the PBC scheme, we propose a holistic approach for lowering the cost of wind turbine ownership while meeting the availability requirement. Our effects are focused on integrated...... firms who design and market wind turbines, and also provide maintenance and repair service. PBC differs from conventional service contracts in that the wind farmers compensate the service provider for the system performance, not the spare parts and repair labor. We explore the analytical relationship...

Measuring the Quality of Ecotourism Services

Directory of Open Access Journals (Sweden)

Nor’Aini Yusof

2014-06-01

Full Text Available Ecotourism forms the pillar of the country’s tourism industry. Ecotourists make up more than 10% of international tourists in Malaysia. When service quality is thought of as an important factor to the success of tourism service providers, the importance of estimating service quality provided to tourists becomes apparent. Estimating service quality provides tourism service providers with the necessary information needed to manage their marketing operations appropriately. Therefore, this estimation should be performed with the right measurement scales. Despite the high volume of research on service quality (SERVQUAL models in recent years, limited effort has been directed toward improving the tool for measuring service quality, particularly to apply to the ecotourism sector in developing countries. This article aims to improve a SERVQUAL model that is suitable for ecotourism areas in developing countries using five dimensions of the original model and one additional sustainability dimension. Based on a survey of 127 tourists in Tasik Kenyir, an exploratory factor analysis (EFA was conducted to discover the underlying dimension of ecotourism services and test for reliability and validity. Using EFA resulted in seven factors totaling 27 items. These factors are labeled as follows: tangible sustainability, sustainable practices, tangibility, reliability, responsiveness, assurance, and empathy. The results reveal that when SERVQUAL is applied within the ecotourism context, new dimensions of tangible sustainability and sustainable practices may emerge. The result implies the need to refine the SERVQUAL model when used in different contexts.

Resource Management in Differentiated Services : A Prototype Implementation

NARCIS (Netherlands)

Jacobsson, Martin; Oosthoek, Simon; Karagiannis, Georgios

The wide deployment of IP technologies has driven the development of IP-based solutions for wireless networks, like the IP-based Radio Access Networks (RAN). Such wireless networks have different characteristics than traditional IP networks, imposing very strict requirements on Quality of Service

Unbundling generation and transmission services for competitive electricity markets

International Nuclear Information System (INIS)

Hirst, E.; Kirby, B.

1998-01-01

Ancillary services are those functions performed by the equipment and people that generate, control, and transmit electricity in support of the basic services of generating capacity, energy supply, and power delivery. The Federal Energy Regulatory Commission (FERC) defined such services as those 'necessary to support the transmission of electric power from seller to purchaser given the obligations of control areas and transmitting utilities within those control areas to maintain reliable operations of the interconnected transmission system.' The nationwide cost of ancillary services is about $12 billion a year, roughly 10% of the cost of the energy commodity. More important than the cost, however, is the necessity of these services for bulk-power reliability and for the support of commercial transactions. FERC's landmark Order 888 included a pro forma tariff with provision for six key ancillary services. The Interconnected Operations Services Working Group identified another six services that it felt were essential to the operation of bulk-power systems. Several groups throughput the United States have created or are forming independent system operators, which will be responsible for reliability and commerce. To date, the electricity industry (including traditional vertically integrated utilities, distribution utilities, power markets and brokers, customers, and state and federal regulators) has paid insufficient attention to these services. Although the industry had made substantial progress in identifying and defining the key services, much remains to be doe to specify methods to measure the production, delivery, and consumption of these services; to identify the costs and cost-allocation factors for these services; and to develop market and operating rules for their provision and pricing. Developing metrics, determining costs, and setting pricing rules are important because most of these ancillary services are produced by the same pieces of equipment that

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

Service quality improvement of ground staff at Don Mueang International Airport

Directory of Open Access Journals (Sweden)

Sittichai Sricharoenpramong

2018-01-01

Full Text Available The purposes of this research were to: 1 evaluate the service quality of the ground staff at Don Mueang International Airport (DMK, 2 compare the ground staff quality service perception of Thai passengers at DMK, and 3 provide guidelines for service quality improvement of the DMK airlines ground staff. A sample size of 400 Thai domestic passengers was accidentally selected at DMK. A questionnaire was used as a research tool for data collection. Five dimensions of service quality were evaluated: reliability, responsiveness, assurance, empathy, and tangibles. It was found that the service quality of ground staff was moderate. The highest dimension of service quality realization was tangibles, followed successively by reliability, assurance, empathy, and responsiveness. The passengers' perception of the ground staff's service quality varied by gender and age group. Guidelines were proposed for the improvement of ground staff service quality at DMK based on the findings. Keywords: airport, ground staff, quality of service

Cross-Cultural Perspectives of Service Quality and Risk in Air Transportation

Science.gov (United States)

Cunningham, Lawrence F.; Young, Clifford E.; Lee, Moonkyu

2002-01-01

This study compares US and Korean customers in terms of their perceptions of airline service quality based on SERVPERF and industry-based measures, as well as their perceptions of risks involved in the airline choice. SERVPERF is a set of multi-dimensional measures of customer evaluations of service quality. The results indicate that: (1) US passengers are generally more satisfied with their airline service than Korean customers on most of the SERVPERF dimensions; (2) Koreans are generally more satisfied with the bumping procedures whereas US participants feel more satisfied with the airline's baggage handling, operations/safety, and connections; and (3) US participants perceive higher levels of performance and financial risks whereas Koreans feel greater social risk in choosing an airline. This study also examines the SERVPERF, industry-based measure, and perceived risk in predicting customer satisfaction with, and intention to repatronize the airline. The results suggest that US customers consider service reliability, in-flight comfort, and connections as the key factors determining satisfaction with airline service whereas Korean passengers generally regard reliability, assurance, and risk factors as predictors of satisfaction. The determining factors of customer intention to repatronize the airline are reliability and empathy for US, and reliability and overall risk for Korean customers. The study demonstrates the applicability of SERVPERF as a cross-cultural tool and indicates the importance of perceived risk in cross-cultural studies.

Electricity supply. Older plants' impact on reliability and air quality

International Nuclear Information System (INIS)

England-Joseph, Judy A.; Adams, Charles M.; Wood, David G.; Feehan, Daniel J.; Veal, Howard F.; Skeen, John H. III; Koenigs, Melvin J.; Lichtenfeld, David I.; Seretakis, Pauline J.

1990-09-01

Life extension of fossil fuel plants is a relatively recent phenomenon; thus, utilities have little experience to demonstrate the longer-term operating reliability of plants with an extended service life. While utility industry officials and government and industry studies express optimism that these plants will continue to operate reliably, the officials and the studies also caution that it is too soon to determine how pursuing life extension will affect the reliability of the nation's electricity supply. According to DOE, the number of fossil fuel generating units' 30 years old or older is expected to increase from about 2,500 in 1989 to roughly 3,700 in 1998, increasing such plants' share of overall generating capacity from 13 percent in 1989 to 27 percent in 1998. EPA estimates that with existing air quality requirements, fossil fuel plant emissions will increase steadily during the coming decade. Proposed acid rain control legislation, which would affect many plants that may have their service life extended, would require utilities to significantly reduce emissions by the year 2000 but would allow utilities flexibility in deciding how and where to achieve the reductions. If such legislation is enacted, utilities generally are expected to find reducing emissions from existing plants more cost-effective than replacing them and to continue extending plants' service life. Officials of DOE and utility organizations expressed concern, however, that EPA could decide, as it did for one plant in 1988, that alterations made in extending the service life of plants exempted from the Clean Air Act would result in increased emissions and thus cause the altered plants to lose their exemption. According to the officials, the additional costs of achieving the Clean Air Act's standards could discourage some life extension projects. However, such decisions by EPA could also reduce the nation's total power plant emissions by eliminating an existing incentive to retain exempt

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.

Pressure pain thresholds, clinical assessment, and differential diagnosis: reliability and validity in patients with myogenic pain.

Science.gov (United States)

Ohrbach, R; Gale, E N

1989-11-01

Four studies are presented testing the validity and reliability of pressure pain thresholds (PPTs) and of examination parameters believed to be important in the clinical assessment of sites commonly used for such measures in patient samples. Forty-five patients with a myogenous temporomandibular disorder were examined clinically prior to PPT measures. Criteria for history and examination included functional aspects of the pain, tissue quality of the pain site, and the type of pain elicited from palpation. Control sites within the same muscle and in the contralateral muscle were also examined. PPTs were measured as an index of tenderness using a strain gauge algometer at these sites. The data from the 5 male subjects were excluded from subsequent analyses due to the higher PPT in the males and to their unequal distribution among the various factorial conditions. The first study demonstrated strong validity in PPT measures between patients (using pain sites replicating the patients' pain) and matched controls (n = 11). The PPT was not significantly different between the primary pain site (referred pain and non-referred pain collapsed) and the no-pain control site in the same muscle (n = 16). The PPT was significantly lower at the pain site compared to the no-pain control site in the contralateral muscle (n = 13). The second study indicated adequate reliability in patient samples of the PPT measures. In the third study, the PPT was significantly lower at sites producing referred pain on palpation compared to sites producing localized pain on palpation. The PPT findings from the control sites were inconsistent on this factor. The fourth study presented preliminary evidence that palpable bands and nodular areas in muscle were most commonly associated with muscle regions that produce pain; such muscle findings were not specific, however, for regions that produce pain. Further, the intraexaminer reliability in reassessing these pain sites qualitatively was only fair

Evaluation of off-service rotations at National Guard Health Affairs: Results from a perception survey of off-service residents

Directory of Open Access Journals (Sweden)

Mustafa M Alquraini

2013-01-01

Full Text Available Context: "Off-service" clinical rotations are part of the necessary requirements for many residency training programs. Because these rotations are off-service, little attention is given to their structure and quality of training. This often leads to suboptimal educational experience for the residents on these rotations. Aims: The aim of this study was to assess medical residents′ perceptions, opinions, and levels of satisfaction with their "off-service" rotations at a major residency training site in Saudi Arabia. It was also to evaluate the reliability and validity of a questionnaire used for quality assurance in these rotations. Improved reliability and validity of this questionnaire may help to improve the educational experience of residents in their "off-service" rotations. Materials and Methods: A close-ended questionnaire was developed, Pilot tested and distributed to 110 off-service residents in training programs of different specializations at King Fahad Naitonal Guard Hospital and King Abdulziz Medical City, Riyadh, Saudi Arabia, between September 2011 and December 2011. Results: A total of 80 out of 110 residents completed and returned the questionnaire. Only 33% of these residents had a clear set of goals and educational learning objectives before the beginning of their off-service rotations to direct their training. Surgical specializations had low satisfaction mean scores of 57.2 (11.9 compared to emergency medicine, which had 70.7 (16.2, P value (0.03. The reliability of the questionnaire was Cronbach′s alpha 0.57. The factor analysis yielded a 4-factor solution (educational environment, educational balance, educational goals and objectives, and learning ability; thus, accounting for 51% variance in the data. Conclusion: Our data suggest that there were significant weaknesses in the curriculum for off-service clinical rotations in KAMC and that residents were not completely satisfied with their training.

Mapping ecosystem services in the St. Louis River estuary (presentation)

Science.gov (United States)

Management of ecosystems for sustainable provision of services beneficial to human communities requires reliable data about from where in the ecosystem services flow. Our objective is to map ecosystem services in the St. Louis River with the overarching EPA goal of community sust...

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)

Evaluation and improvement of nondestructive evaluation reliability for inservice inspection of light water reactors

International Nuclear Information System (INIS)

Bates, D.J.; Deffenbaugh, J.D.; Good, M.S.; Heasler, P.G.; Mart, G.A.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.; Van Fleet, L.G.

1987-01-01

The Evaluation and Improvement of NDE Reliability for Inservice Inspection (ISI) of Light Water Reactors (NDE Reliability) Program at Pacific Northwest Laboratory (PNL) was established to determine the reliability of current ISI techniques and to develop recommendations that will ensure a suitably high inspection reliability. The objectives of this NRC program are to: determine the reliability of ultrasonic ISI performed on commercial light-water reactor (LWR) primary systems, using probabilistic fracture mechanics analysis, determine the impact of NDE unreliability on system safety and determine the level of inspection reliability required to ensure a suitably low failure probability, evaluate the degree of reliability improvement that could be achieved using improved and advanced NDE techniques, based on material properties, service conditions, and NDE uncertainties, recommend revisions to ASME Code, Section XI, and Regulatory Requirements that will ensure suitably low failure probabilities. The scope of this program is limited to ISI of primary systems; the results and recommendations may also be applicable to Class II piping systems

Test-retest reliability of schizoaffective disorder compared with schizophrenia, bipolar disorder, and unipolar depression--a systematic review and meta-analysis.

Science.gov (United States)

Santelmann, Hanno; Franklin, Jeremy; Bußhoff, Jana; Baethge, Christopher

2015-11-01

Schizoaffective disorder is a frequent diagnosis, and its reliability is subject to ongoing discussion. We compared the diagnostic reliability of schizoaffective disorder with its main differential diagnoses. We systematically searched Medline, Embase, and PsycInfo for all studies on the test-retest reliability of the diagnosis of schizoaffective disorder as compared with schizophrenia, bipolar disorder, and unipolar depression. We used meta-analytic methods to describe and compare Cohen's kappa as well as positive and negative agreement. In addition, multiple pre-specified and post hoc subgroup and sensitivity analyses were carried out. Out of 4,415 studies screened, 49 studies were included. Test-retest reliability of schizoaffective disorder was consistently lower than that of schizophrenia (in 39 out of 42 studies), bipolar disorder (27/33), and unipolar depression (29/35). The mean difference in kappa between schizoaffective disorder and the other diagnoses was approximately 0.2, and mean Cohen's kappa for schizoaffective disorder was 0.50 (95% confidence interval: 0.40-0.59). While findings were unequivocal and homogeneous for schizoaffective disorder's diagnostic reliability relative to its three main differential diagnoses (dichotomous: smaller versus larger), heterogeneity was substantial for continuous measures, even after subgroup and sensitivity analyses. In clinical practice and research, schizoaffective disorder's comparatively low diagnostic reliability should lead to increased efforts to correctly diagnose the disorder. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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)

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)

Evaluation of piping reliability and failure data for use in risk-based inspections of nuclear power plants

International Nuclear Information System (INIS)

Vasconcelos, V. de; Soares, W.A.; Costa, A.C.L. da; Rabello, E.G.; Marques, R.O.

2016-01-01

During operation of industrial facilities, components and systems can deteriorate over time, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) involves inspection planning based on information about risks, through assessing of probability and consequence of failures. In-service inspections are used in nuclear power plants, in order to ensure reliable and safe operation. Traditional deterministic inspection approaches investigate generic degradation mechanisms on all systems. However, operating experience indicates that degradation occurs where there are favorable conditions for developing a specific mechanism. Inspections should be prioritized at these places. Risk-Informed In-service Inspections (RI-ISI) are types of RBI that use Probabilistic Safety Assessment results, increasing reliability and plant safety, and reducing radiation exposure. These assessments use both available generic reliability and failure data, as well as plant specific information. This paper proposes a method for evaluating piping reliability and failure data important for RI-ISI programs, as well as the techniques involved. (author)

Evaluation of piping reliability and failure data for use in risk-based inspections of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Vasconcelos, V. de; Soares, W.A.; Costa, A.C.L. da; Rabello, E.G.; Marques, R.O., E-mail: vasconv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2016-07-01

During operation of industrial facilities, components and systems can deteriorate over time, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) involves inspection planning based on information about risks, through assessing of probability and consequence of failures. In-service inspections are used in nuclear power plants, in order to ensure reliable and safe operation. Traditional deterministic inspection approaches investigate generic degradation mechanisms on all systems. However, operating experience indicates that degradation occurs where there are favorable conditions for developing a specific mechanism. Inspections should be prioritized at these places. Risk-Informed In-service Inspections (RI-ISI) are types of RBI that use Probabilistic Safety Assessment results, increasing reliability and plant safety, and reducing radiation exposure. These assessments use both available generic reliability and failure data, as well as plant specific information. This paper proposes a method for evaluating piping reliability and failure data important for RI-ISI programs, as well as the techniques involved. (author)

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)

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

Multiparametric MR imaging in diagnosis of chronic prostatitis and its differentiation from prostate cancer

Directory of Open Access Journals (Sweden)

Vivek Kumar Sah

2015-03-01

Full Text Available Chronic prostatitis is a heterogeneous condition with high prevalence rate. Chronic prostatitis has overlap in clinical presentation with other prostate disorders and is one of the causes of high serum prostate specific antigen (PSA level. Chronic prostatitis, unlike acute prostatitis, is difficult to diagnose reliably and accurately on the clinical grounds alone. Not only this, it is also challenging to differentiate chronic prostatitis from prostate cancer with imaging modalities like TRUS and conventional MR Imaging, as the findings can mimic those of prostate cancer. Even biopsy doesn't play promising role in the diagnosis of chronic prostatitis as it has limited sensitivity and specificity. As a result of this, chronic prostatitis may be misdiagnosed as a malignant condition and end up in aggressive surgical management resulting in increased morbidity. This warrants the need of reliable diagnostic tool which has ability not only to diagnose it reliably but also to differentiate it from the prostate cancer. Recently, it is suggested that multiparametric MR Imaging of the prostate could improve the diagnostic accuracy of the prostate cancer. This review is based on the critically published literature and aims to provide an overview of multiparamateric MRI techniques in the diagnosis of chronic prostatitis and its differentiation from prostate cancer.

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)

Franchising - a partnership model for efficient water services operation and maintenance

CSIR Research Space (South Africa)

Wall, K

2007-05-01

Full Text Available There is a need in South Africa for institutional innovations aimed at increasing the coverage and reliability of water services, and sustaining those services. The paper describes an alternative service delivery institutional concept, viz...

Differentiation of energy concepts through speech and gesture in interaction

Science.gov (United States)

Close, Hunter G.; Scherr, Rachel E.

2012-02-01

Through microanalysis of speech and gesture in one interaction between learners (in a course on energy for in-service teachers), we observe coherent states of conceptual differentiation of different learners. We observe that the interaction among learners across different states of differentiation is not in itself sufficient to accomplish differentiation; however, the real-time receptivity of the learners to conceptually relevant details in each other's actions suggests that future instruction that focuses explicitly on such actions and their meaning in context may assist differentiation.

Exploring public bus service quality in South Africa: A structural equation modelling approach

Directory of Open Access Journals (Sweden)

Ayanda M. Vilakazi

2014-07-01

Full Text Available This study, which is a deviation from the usual practice of using SERVQUAL or an adaptedversion thereof, uses McKnight, Pagano and Paaswell’s (1986 service quality dimensions,namely reliability; extent of service; comfort; safety; and affordability (RECSA and structuralequation modelling to determine commuters’ perception of public bus service quality in amajor city in South Africa. The RECSA model was adapted and fitted to the data collectedfrom a convenience sample of bus commuters in Johannesburg, using structural equationmodelling. It was ascertained that reliability, service, comfort and safety influenced thepublic bus commuters’ perception of the overall service quality. The implications of theaforementioned findings for providers of public bus services are explained.

Impact of inservice inspection on the reliability of pressure vessels and piping

International Nuclear Information System (INIS)

Bush, S.H.

1975-01-01

The reliability of pressure components of a nuclear reactor is a function of the as-fabricated quality plus a program of continuing inspection during operation. Since insufficient data exist to quantitatively determine failure probabilities of nuclear pressure vessels and piping, it is necessary to utilize information from comparable non-nuclear systems such as power boilers. Based on probabilistic studies it is inferred that in-service inspection improves component reliability one-to-two orders of magnitude depending on the type and completeness of the inspections. An attempt is made to assess the significance of the ASME Section XI Code as to relative completeness of inspection and the probable improvement in reliability. (U.S.)

Impact of inservice inspection on the reliability of pressure vessels and piping

International Nuclear Information System (INIS)

Bush, S.H.

1974-01-01

The reliability of pressure components of a nuclear reactor is a function of the quality as-fabricated plus a program of continuing inspection during operation. Since insufficient data exist to quantitatively determine failure probabilities of nuclear pressure vessels and piping, it is necessary to utilize information from comparable non-nuclear systems such as power boilers. Based on probabilistic studies it is inferred that in-service inspection improves component reliability one-to-two orders of magnitude depending on the type and completeness of the inspections. An attempt is made to assess the significance of the ASME Section XI Code as to relative completeness of inspection and the probable improvement in reliability. (U.S.)

NDT reliability in the organizational context of service inspection companies

International Nuclear Information System (INIS)

Holstein, Ralf; Bertovic, Marija; Kanzler, Daniel; Mueller, Christina

2014-01-01

The focus of NDT reliability research in the past was in the field of two high risk industries: (atomic) power plants and aircrafts. The responsible organizations have been well aware of the risks and founded projects to understand and optimize critical steps during production, operation and maintenance. But the use of NDT is not limited to these two fields. The risks during operation of chemical plants, trains or windmills are different from the area above but evident. The coverage by legal regulations is relatively low. Instead of this owner responsibility, product liability and financial issues are the driving forces to do inspections and to use non-destructive testing. The different targets and financial issues influence the practice of NDT-inspections. A survey of this practice and its results are shown. (orig.)

Estimating the Service Lives of Building Products in Use

NARCIS (Netherlands)

Straub, A.

2015-01-01

Reliable service life data of building products are of great importance when completing environmental LCA (life cycle assessment) reviews, for LCC (life cycle costing) and for maintenance planning tasks. A research project was set up to answer the following research questions: (1) what are reliable

Equilibrium moisture content of wood at different temperature/moisture conditions in the cladding of wooden constructions and in the relation to their reliability and service life

Directory of Open Access Journals (Sweden)

Zdeňka Havířová

2010-01-01

Full Text Available One of the natural properties of wood and wood-based materials is their soaking capacity (hy­gro­sco­pi­ci­ty. The moisture content of wood and building constructions of wood and wood based materials significantly influences the service life and reliability of these constructions and buildings. The equilibrium weight moisture content of built-in wood corresponding to temperature/moisture conditions inside the cladding has therefore a decisive influence on the basic requirements placed on building constructions. The wood in wooden frame cladding changes its moisture content depending on temperature and moisture conditions of the environment it is built into. The water vapor condensation doesn’t necessarily have to occur right in the wooden framework of the cladding for the equilibrium moisture content to rise over the level permissible for the reliable function of a given construction. In spite of the fact that the common heat-technical assessment cannot be considered fully capable of detecting the effects of these factors on the functional reliability of wood-based constructions and buildings, an extension has been proposed of the present method of design an assessment of building constructions according to the ČSN 73 0540 standard regarding the interpretation of equilibrium moisture content in relation to the temperature/moisture conditions and their time behavior inside a construction.

E-Service Quality Evaluation on E-Government Website: Case Study BPJS Kesehatan Indonesia

Science.gov (United States)

Rasyid, A.; Alfina, I.

2017-01-01

This research intends to develop a model to evaluate the quality of e-services on e-government. The proposed model consists of seven dimensions: web design, reliability, responsiveness, privacy and security, personalization, information, and ease of use. The model is used to measure the quality of the e-registration of BPJS Kesehatan, an Indonesian government health insurance program. The validation and reliability testing show that of the seven dimensions proposed, only four that suitable for the case study. The result shows that the BPJS Kesehatan e-registration service is good in reliability and responsiveness dimensions, while from web design and ease of use dimensions the e-service still needs to be optimized.

Maintenance management of railway infrastructures based on reliability analysis

International Nuclear Information System (INIS)

Macchi, Marco; Garetti, Marco; Centrone, Domenico; Fumagalli, Luca; Piero Pavirani, Gian

2012-01-01

Railway infrastructure maintenance plays a crucial role for rail transport. It aims at guaranteeing safety of operations and availability of railway tracks and related equipment for traffic regulation. Moreover, it is one major cost for rail transport operations. Thus, the increased competition in traffic market is asking for maintenance improvement, aiming at the reduction of maintenance expenditures while keeping the safety of operations. This issue is addressed by the methodology presented in the paper. The first step of the methodology consists of a family-based approach for the equipment reliability analysis; its purpose is the identification of families of railway items which can be given the same reliability targets. The second step builds the reliability model of the railway system for identifying the most critical items, given a required service level for the transportation system. The two methods have been implemented and tested in practical case studies, in the context of Rete Ferroviaria Italiana, the Italian public limited company for railway transportation.

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...

An Assessment of Customer Service in the Nigeria ...

African Journals Online (AJOL)

This study examined customer services in the Nigeria telecommunication industry by comparing Zain and MTN companies. Primary data were collected from a total of 60 respondents. Data collected were on consumer service elements such as: reliability, delivery frequency, delivery accuracy, quality of salespeople, ...

The Importance of Perceived Service Value in Retail Banking Services

Directory of Open Access Journals (Sweden)

Aleksandra Pisnik

2016-12-01

Full Text Available Purpose – In many industries, perceived service value is found to be a significant mediator between perceived service quality and customer satisfaction and loyalty. Therefore, this paper aims to test a conceptual model of perceived service value with its antecedents, such as perceived price and perceived service quality, and consequences, customer satisfaction and loyalty, in the retail banking industry. Design/Methodology/Approach – For the empirical study, a measurement instrument was developed and tested for validity and reliability. Measures were assessed with exploratory factor analysis (EFA, confirmatory factor analysis (CFA and structural equation modeling (SEM. A structural model with five reflective constructs was evaluated to test direct and indirect relationships among constructs. Findings and implications – Results confirm a mediating role of perceived value in relationships between perceived price, perceived service quality, customer satisfaction, and customer loyalty in the case of retail banking services. Limitations – Because the results are directly relevant only to customers and marketing managers of retail banking services, generalizations of the findings beyond the immediate population observed should be made with caution. Originality – This paper extends existing knowledge with both direct and indirect effects among researched concepts, and shows the importance of perceived service value in achieving satisfied and loyal customers in retail banking services.

Solving Nonlinear Fractional Differential Equation by Generalized Mittag-Leffler Function Method

Science.gov (United States)

Arafa, A. A. M.; Rida, S. Z.; Mohammadein, A. A.; Ali, H. M.

2013-06-01

In this paper, we use Mittag—Leffler function method for solving some nonlinear fractional differential equations. A new solution is constructed in power series. The fractional derivatives are described by Caputo's sense. To illustrate the reliability of the method, some examples are provided.

Reliability of high-voltage pulse capacitors operating in large energy storages

International Nuclear Information System (INIS)

Kuchinskij, G.S.; Fedorova, V.S.; Shilin, O.V.

1982-01-01

To improve the reliability of pulse capacitors operating in capacitive energy storages, processes, resulting in break-down of capacitor insulation were investigated. A statistic model of failures was constructed and reliability of real capacitors, functioning at operating electric intensity Usub(oper) equal 70 kV/mm and at elevated intensity 90 kV/mm was calculated. Results of testing the IK50-ZU4 capacitor are given. The form of the capacitor service life distribution function was specified. To provide and confirm the assigned capacitor reliability, it is necessary to speed up tests at a higher voltage (1.3-1.5) Usub(oper). To improve the capacitor reliability, it is advisable to conduct acceptance tests, which include hold at increased constant voltage (1.3-1.5) Usub(oper) during 1-3 min and the effect of pulses of increased voltage (1.2-1.3) Usub(oper) with the pulse shape corresponding to operating conditions

Improving the Efficiency of Administrative Decision-Making when Monitoring Reliability and Safety of Oil and Gas Equipment

Directory of Open Access Journals (Sweden)

Zemenkova Maria

2016-01-01

Full Text Available Methodology of rapid assessment of reliability index was developed based on system analysis of technological parameters. Within functioning of on-line monitoring system of reliability index of industrial facility this method allows to increase efficiency of making managerial decisions on technical and preventive maintenance. The technique is based on the analysis of technological parameters of operational modes of pipeline transport facilities registered by dispatcher controls. The created technique can be used by the operating, research, design institutes and oil and gas transport enterprises when declaring industrial safety. The received mathematical models allow federal services of supervision, the independent expert organizations to predict the development of reliability in the registered block of dispatching data either in real time mode, or taking into account the dynamics of service conditions of the object.

Compilation of the calculation elements of the electronic equipments reliability

International Nuclear Information System (INIS)

Lefevre, R.; D'Harcourt, A.; Dupuy, G.

1968-01-01

The aim of this work is to allow the practical execution of the estimated calculation of the electronic devices reliability and to standardize the source and the approach of the calculations while giving a systematic character to their execution mode. The systematic character of the calculations allows a comparison of the reliability of different materials and a rapid control of the calculations validity; at last, it brings out the use conditions of all the components of a set. A reliability calculation made according to the method described here reveals: -components badly used -the relative influence on the reliability of the set, of a component or a components group taking into account of the number, of the characteristics and of the use of these ones. At last, the results of the calculation allows to organize the exploitation (availability) and the maintenance (staff, stock of components) of the materials. The failure rates given in this book are only relating to the components service-life and do not correspond to precocious failures. (authors) [fr

Child and adolescent service experience (ChASE): measuring service quality and therapeutic process.

Science.gov (United States)

Day, Crispin; Michelson, Daniel; Hassan, Imren

2011-11-01

OBJECTIVES. Dissatisfaction with services has been associated with poorer child mental health outcomes, early treatment termination as well as disagreements over the nature of mental health difficulties, reasons for referral and therapy goals. The development of straightforward, reliable, and accurate methods of eliciting service users' views is essential within child and adolescent mental health care. This paper describes the development of the child and adolescent service experience (ChASE), a tool to measure children and young people's service experience DESIGN. The study comprises a non-experimental, cross-sectional design. METHODS. Participants were 132 mental health service users aged 8-18 years. Participants and their main carer completed the ChASE, Parent Satisfaction Questionnaire (PSQ) (Stallard, 1996) and Strengths and Difficulties (SDQ) Impact Supplement. Clinicians completed the SDQ Impact Supplement and provided clinical activity data. A sub-sample of participants completed the ChASE on a second occasion, 6 weeks after the completion of the first questionnaire. RESULTS. Scrutiny of ChASE data indicated high levels of completion. Principal axis factoring identified three factors within the ChASE: Relationship, Privacy, and Session Activity. The ChASE has good internal consistency and test-retest reliability. Significant correlations were found between the ChASE and carer satisfaction, service use, and youth clinical outcomes. CONCLUSIONS. The ChASE is a short, psychometrically robust tool for routine measurement of children, and young people's experience of mental health services, which users can complete easily. The results underline the importance of alliance factors to children and young people and their association with clinical improvement as well as the potential for the ChASE to be used a measure of children's therapeutic progress and alliance. ©2011 The British Psychological Society.

Technical report on the Piping Reliability Proving Tests at the Japan Atomic Energy Research Institute

International Nuclear Information System (INIS)

1993-05-01

Japan Atomic Energy Research Institute (JAERI) conducts Piping Reliability Proving Tests from 1975 to 1992 based upon the contracts between JAERI and Science and Technology Agency of Japan (STA) under the auspices of the special account law for electric power development promotion. The purpose of these tests are to prove the structural reliability of the primary cooling piping constituting a part of the pressure boundary in the light water reactor power plants. The tests with large experimental facilities had ended already in 1990. Presently piping reliability analysis by the probabilistic fracture mechanics method is being done. Until now annual reports concerning the proving tests were produced and submitted to STA, whereas this report summarizes the test results done during these 16 years. Objectives of the piping reliability proving tests are to prove that the primary piping of the light water reactor (1) be reliable throughout the service period, (2) have no possibility of rupture, (3) bring no detrimental influence on the surrounding instrumentations or equipments near the break location even if it ruptured suddenly. To attain these objectives (i) pipe fatigue tests, (ii) unstable pipe fracture tests, (iii) pipe rupture tests and also the analyses by computer codes were done. After carrying out these tests, it is verified that the piping is reliable throughout the service period. The authors of this report are T. Isozaki, K. Shibata, S. Ueda, R. Kurihara, K. Onizawa and A. Kohsaka. The parts they wrote are shown in contents. (author)

High pressure, high current, low inductance, high reliability sealed terminals

Science.gov (United States)

Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

2010-03-23

The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

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....

Reliability and Validity of Modified Service Quality Instrument (SERVQUAL) in Patients' Motivation to Adhere to Insulin Therapy.

Science.gov (United States)

Jakupovic, Vedran; Solakovic, Suajb; Celebic, Nedim; Kulovic, Dzenan

2018-03-01

Diabetes is progressive condition which requires various ways of treatment. Adequate therapy prescribed in the right time helps patient to postpone development of complications. Adherence to complicated therapy is challenge for both patients and HCPs and is subject of research in many disciplines. Improvement in communication between HCP and patients is very important in patient's adherence to therapy. Aim of this research was to explore validity and reliability of modified SERVQUAL instrument in attempt to explore ways of motivating diabetic patient to accept prescribed insulin therapy. We used modified SERVQUAL questionnaire as instrument in the research. It was necessary to check validity and reliability of the new modified instrument. Results show that modified Servqual instrument has excellent reliability (α=0.908), so we could say that it measures precisely Expectations, Perceptions and Motivation at patients. Factor analysis (EFA method) with Varimax rotation extracted 4 factors which together explain 52.902% variance of the results on this subscale. Bifactorial solution could be seen on Scree-plot diagram (break at second factor). Results in this research show that modified Servqual instrument which is created in order to measure expectations and perceptions of the patients is valid and reliable. Reliability and validity are proven indeed in additional dimension which was created originally for this research - motivation to accept insulin therapy.

Reliability and Validity of Modified Service Quality Instrument (SERVQUAL) in Patients’ Motivation to Adhere to Insulin Therapy

Science.gov (United States)

Jakupovic, Vedran; Solakovic, Suajb; Celebic, Nedim; Kulovic, Dzenan

2018-01-01

Introduction: Diabetes is progressive condition which requires various ways of treatment. Adequate therapy prescribed in the right time helps patient to postpone development of complications. Adherence to complicated therapy is challenge for both patients and HCPs and is subject of research in many disciplines. Improvement in communication between HCP and patients is very important in patient’s adherence to therapy. Aim: Aim of this research was to explore validity and reliability of modified SERVQUAL instrument in attempt to explore ways of motivating diabetic patient to accept prescribed insulin therapy. Material and Methods: We used modified SERVQUAL questionnaire as instrument in the research. It was necessary to check validity and reliability of the new modified instrument. Results: Results show that modified Servqual instrument has excellent reliability (α=0.908), so we could say that it measures precisely Expectations, Perceptions and Motivation at patients. Factor analysis (EFA method) with Varimax rotation extracted 4 factors which together explain 52.902% variance of the results on this subscale. Bifactorial solution could be seen on Scree-plot diagram (break at second factor). Conclusion: Results in this research show that modified Servqual instrument which is created in order to measure expectations and perceptions of the patients is valid and reliable. Reliability and validity are proven indeed in additional dimension which was created originally for this research - motivation to accept insulin therapy. PMID:29670478

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....

Fault recovery in the reliable multicast protocol

Science.gov (United States)

Callahan, John R.; Montgomery, Todd L.; Whetten, Brian

1995-01-01

The Reliable Multicast Protocol (RMP) provides a unique, group-based model for distributed programs that need to handle reconfiguration events at the application layer. This model, called membership views, provides an abstraction in which events such as site failures, network partitions, and normal join-leave events are viewed as group reformations. RMP provides access to this model through an application programming interface (API) that notifies an application when a group is reformed as the result of a some event. RMP provides applications with reliable delivery of messages using an underlying IP Multicast (12, 5) media to other group members in a distributed environment even in the case of reformations. A distributed application can use various Quality of Service (QoS) levels provided by RMP to tolerate group reformations. This paper explores the implementation details of the mechanisms in RMP that provide distributed applications with membership view information and fault recovery capabilities.

Areva: experiences in outage services

International Nuclear Information System (INIS)

Wiemeier, R.; Mueller, N.; Blanco, I. J.

2010-01-01

As the world leader in the nuclear industry, Areva is firmly committed to the safe and reliable operation of the Spanish nuclear power plants. Following this commitment, Areva has established the subsidiary Areva NP Services Spain as a local platform to provide nuclear services for the Spanish nuclear power plants. being integrated and supported by the global Areva Group, Areva NP Services Spain is able to offer services solutions to all customers demands while maintaining close and sustainable relationships with them. This integration also allows the Spanish personnel of Areva to employ their skills by working in multinational teams in international projects. This article will present the capacities, and the most important recent national and international project performed by Areva NP Services Spain in the field of outage services. (Author)

Evaluation of products and services of a nursing library: user satisfaction

OpenAIRE

Cozin,Sheila Kátia; Turrini,Ruth Natalia Teresa

2008-01-01

The goal of the study was to evaluate the quality of the services provided by the library at the Nursing School of the University of São Paulo. A questionnaire evaluating users' satisfaction with the service was employed, covering five quality components: tangibles, reliability, responsiveness, assurance and empathy. The Satisfaction Rate was calculated through the degree of importance in relation to satisfaction. The analysis of the open-ended answers was quanti-qualitative. For Reliability ...

Health Services OutPatient Experience questionnaire: factorial validity and reliability of a patient-centered outcome measure for outpatient settings in Italy

Directory of Open Access Journals (Sweden)

Coluccia A

2014-09-01

Full Text Available Anna Coluccia, Fabio Ferretti, Andrea PozzaDepartment of Medical Sciences, Surgery and Neurosciences, Santa Maria alle Scotte University Hospital, University of Siena, Siena, ItalyPurpose: The patient-centered approach to health care does not seem to be sufficiently developed in the Italian context, and is still characterized by the biomedical model. In addition, there is a lack of validated outcome measures to assess outpatient experience as an aspect common to a variety of settings. The current study aimed to evaluate the factorial validity, reliability, and invariance across sex of the Health Services OutPatient Experience (HSOPE questionnaire, a short ten-item measure of patient-centeredness for Italian adult outpatients. The rationale for unidimensionality of the measure was that it could cover global patient experience as a process common to patients with a variety of diseases and irrespective of the phase of treatment course.Patients and methods: The HSOPE was compiled by 1,532 adult outpatients (51% females, mean age 59.22 years, standard deviation 16.26 receiving care in ten facilities at the Santa Maria alle Scotte University Hospital of Siena, Italy. The sample represented all the age cohorts. Twelve percent were young adults, 57% were adults, and 32% were older adults. Exploratory and confirmatory factor analyses were conducted to evaluate factor structure. Reliability was evaluated as internal consistency using Cronbach’s α. Factor invariance was assessed through multigroup analyses.Results: Both exploratory and confirmatory analyses suggested a clearly defined unidimensional structure of the measure, with all the ten items having salient loadings on a single factor. Internal consistency was excellent (α=0.95. Indices of model fit supported a single-factor structure for both male and female outpatient groups. Young adult outpatients had significantly lower scores on perceived patient-centeredness relative to older adults. No

Trust management support for context-aware service platforms

NARCIS (Netherlands)

Neisse, R.; Wegdam, M.; van Sinderen, Marten J.; Aldini, A.; Bogliolo, A.

High quality context information retrieved from trustworthy context providers allows a more reliable context-aware service adaption but also implies a higher risk for the service users in case of privacy violations. In this chapter we present a trust management model that support users and providers

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

Power Efficient Service Differentiation Based on Traffic-Aware Survivable Elastic Optical Networks

DEFF Research Database (Denmark)

Turus, Ioan; Fagertun, Anna Manolova; Dittmann, Lars

2014-01-01

This study assesses the feasible energy savings whendefining different service classes based on protection schemesincore optical networks.Wepropose a dedicated energy savingstrategy for each of the service classes in order to minimize theoverall power consumption of the network.Four Classes of Se...... while for the proposed approach the difference in power consumption is almost negligible.Moreover, incase of the proposed approach,silver serviceclass can benefit for superior quality of service compared to the gold service class, due to the grooming mechanism.......This study assesses the feasible energy savings whendefining different service classes based on protection schemesincore optical networks.Wepropose a dedicated energy savingstrategy for each of the service classes in order to minimize theoverall power consumption of the network.Four Classes...... the sleep-mode capability of the opto-electronic devices as well as the elastic data-rateadaptation based on symbol-rate and modulation-format re-configurations. The results show that in the baseline approach the power consumption is strongly dependent on the ratio between the different service classes...

Privately Provided Accommodation Service Quality and Customer Satisfaction

Directory of Open Access Journals (Sweden)

Joshua Mugambwa

2016-04-01

Full Text Available Privately provided accommodation is a growing service in Uganda’s higher education sector due to education liberalization and demand for education. This research took a case study of Nsamizi Training Institute of Social Development (NTISD to determine the relationship between privately provided accommodation service quality and customer satisfaction. Specifically, the objectives of the study were (a to find out the relationship between security and NTISD students’ satisfaction with privately provided accommodation, and (b to find out the hierarchical level of importance of NTISD student satisfaction of the three service quality dimensions (reliability, security, and tangibles with privately provided accommodation. Using quantitative and qualitative modes of data analysis and a sample of 300 students from 20 private hostels, this study established a strong positive significant relationship between security and satisfaction regarding privately provided accommodation. This implies that accommodation service providers should increase the quality of security so as to increase the satisfaction of students regarding privately provided accommodation. The study established the hierarchical order of importance from the most important service quality dimension, respectively, as follows: reliability, security, and tangibles. Therefore, private accommodation service managers should pay extra attention to the dimensions in the same order.

Lecture 8: Data Reliability at CERN and Ideas on How to Improve it

CERN Multimedia

CERN. Geneva

2013-01-01

The talk will give an overview of data management activities at CERN focusing on the ongoing research activities aiming to improve data and service reliability. Alberto Pace is a member if the IT department at CERN where he leads the Data and Storage services group ensuring a coherent development process for Physics Data management activities, strongly driven by operational and user needs. He has more than 25 years experience in computing services, infrastructure, software engineering, accelerator control and accelerator operation. He graduated in Electronic Engineering from Politecnico di Milano (Italy).

Critical spare parts ordering decisions using conditional reliability and stochastic lead time

International Nuclear Information System (INIS)

Godoy, David R.; Pascual, Rodrigo; Knights, Peter

2013-01-01

Asset-intensive companies face great pressure to reduce operation costs and increase utilization. This scenario often leads to over-stress on critical equipment and its spare parts associated, affecting availability, reliability, and system performance. As these resources impact considerably on financial and operational structures, the opportunity is given by demand for decision-making methods for the management of spare parts processes. We proposed an ordering decision-aid technique which uses a measurement of spare performance, based on the stress–strength interference theory; which we have called Condition-Based Service Level (CBSL). We focus on Condition Managed Critical Spares (CMS), namely, spares which are expensive, highly reliable, with higher lead times, and are not available in store. As a mitigation measure, CMS are under condition monitoring. The aim of the paper is orienting the decision time for CMS ordering or just continuing the operation. The paper presents a graphic technique which considers a rule for decision based on both condition-based reliability function and a stochastic/fixed lead time. For the stochastic lead time case, results show that technique is effective to determine the time when the system operation is reliable and can withstand the lead time variability, satisfying a desired service level. Additionally, for the constant lead time case, the technique helps to define insurance spares. In conclusion, presented ordering decision rule is useful to asset managers for enhancing the operational continuity affected by spare parts