RELIABILITY MODEL FOR COMPONENT-BASED SYSTEMS IN COSMIC (A CASE STUDY)

2008 ◽  
Vol 18 (04) ◽  
pp. 515-539 ◽  
Author(s):  
OLGA ORMANDJIEVA ◽  
MANAR ABU TALIB ◽  
ALAIN ABRAN
Keyword(s):  
System Reliability ◽  
Reliability Assessment ◽  
Software Component ◽  
Assessment Model ◽  
Assessment Process ◽  
Component Technology ◽  
Substantial Impact ◽  
Effort Reduction ◽  
Typical Component

Software component technology has a substantial impact on modern IT evolution. The benefits of this technology, such as reusability, complexity management, time and effort reduction, and increased productivity, have been key drivers of its adoption by industry. One of the main issues in building component-based systems is the reliability of the composed functionality of the assembled components. This paper proposes a reliability assessment model based on the architectural configuration of a component-based system and the reliability of the individual components, which is usage- or testing-independent. The goal of this research is to improve the reliability assessment process for large software component-based systems over time, and to compare alternative component-based system design solutions prior to implementation. The novelty of the proposed reliability assessment model lies in the evaluation of the component reliability from its behavior specifications, and of the system reliability from its topology; the reliability assessment is performed in the context of the implementation-independent ISO/IEC 19761:2003 International Standard on the COSMIC method chosen to provide the component's behavior specifications. In essence, each component of the system is modeled by a discrete time Markov chain behavior based on its behavior specifications with extended-state machines. Then, a probabilistic analysis by means of Markov chains is performed to analyze any uncertainty in the component's behavior. Our hypothesis states that the less uncertainty there is in the component's behavior, the greater the reliability of the component. The system reliability assessment is derived from a typical component-based system architecture with composite reliability structures, which may include the composition of the serial reliability structures, the parallel reliability structures and the p-out-of-n reliability structures. The approach of assessing component-based system reliability in the COSMIC context is illustrated with the railroad crossing case study.

scholarly journals Reliability Assessment of Space Station Based on Multi-Layer and Multi-Type Risks

2021 ◽  
Vol 11 (21) ◽  
pp. 10258
Author(s):  
Xiaopeng Li ◽  
Fuqiu Li
Keyword(s):  
System Reliability ◽  
Early Stage ◽  
Space Station ◽  
Reliability Assessment ◽  
Assessment Method ◽  
Assessment Process ◽  
Reliability Model ◽  
Using Data ◽  
Propagation Feature ◽  
Sufficient Test

A space station is a typical phased-mission system, and assessing its reliability during its configuration is an important engineering action. Traditional methods usually require extensive data to carry out a layered reliability assessment from components to the system. These methods suffer from lack of sufficient test data, and the assessment process becomes very difficult, especially in the early stage of the configuration. This paper proposes a reliability assessment method for the space station configuration mission, using multi-layer and multi-type risks. Firstly, the risk layer and the risk type for the space station configuration are defined and identified. Then, the key configuration risks are identified comprehensively, considering their occurrence likelihood and consequence severity. High load risks are identified through risk propagation feature analysis. Finally, the configuration reliability model is built and the state probabilities are computed, based on the probabilistic risk propagation assessment (PRPA) method using the assessment probability data. Two issues are addressed in this paper: (1) how to build the configuration reliability model with three layers and four types of risks in the early stage of the configuration; (2) how to quantitatively assess the configuration mission reliability using data from the existing operational database and data describing the propagation features. The proposed method could be a useful tool for the complex aerospace system reliability assessment in the early stage.

Resource Allocation for System Reliability Assessment Using Accelerated Life Testing

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Kassem Moustafa ◽  
Zhen Hu ◽  
Zissimos P. Mourelatos ◽  
Igor Baseski ◽  
Monica Majcher
Keyword(s):  
Resource Allocation ◽  
System Reliability ◽  
Failure Time ◽  
Reliability Assessment ◽  
Accelerated Life Test ◽  
Assessment Process ◽  
System Level ◽  
Component Level ◽  
Accelerated Life ◽  
Failure Time Distributions

Abstract Accelerated life test (ALT) has been widely used to accelerate the product reliability assessment process by testing a product at higher than nominal stress conditions. For a system with multiple components, the tests can be performed at component-level or system-level. The data at these two levels require different amount of resources to collect and carry different values of information for system reliability assessment. Even though component-level tests are cheap to perform, they cannot account for the correlations between the failure time distributions of different components. While system-level tests can naturally account for the complicated dependence between component failure time distributions, the required testing efforts are much higher than that of component-level tests. This research proposes a novel resource allocation framework for ALT-based system reliability assessment. A physics-informed load model is first employed to bridge the gap between component-level tests and system-level tests. An optimization framework is then developed to effectively allocate testing resources to different types of tests. The information fusion of component-level and system-level tests allows us to accurately estimate the system reliability with a minimized requirement on the testing resources. Results of two numerical examples demonstrate the effectiveness of the proposed framework.

scholarly journals Vulnerability Analysis for Reusing an Old Industrial Area: A Case Study of the Winter Olympic Park

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Wei Tian ◽  
Xingrun Zhong ◽  
Ping Guo ◽  
Guangmin Zhang
Keyword(s):  
Vulnerability Assessment ◽  
Quantitative Methods ◽  
Cloud Model ◽  
Industrial Area ◽  
Indicator System ◽  
Vulnerability Analysis ◽  
Assessment Model ◽  
Assessment Process ◽  
Industrial Areas

Reuse of old industrial areas strongly impacts urban renewal and social development. However, it is limited by significant pollution and damage of buildings. In the decision-making stage, it is necessary to conduct a reasonable vulnerability analysis of old industrial areas. This study focuses on establishing a reasonable and effective vulnerability assessment model to be used in actual work. First, based on literature analysis, a normal cloud model was employed to establish the assessment process and model. Second, foundation damage, structural bearing capacity, and other building safety indicators, as well as environmental safety, were included in the vulnerability assessment indicator system. Thus, through indicator selection and optimization, the vulnerability assessment indicators and their quantitative methods were determined and parameter features of the cloud model were programmed by the forward cloud generator. Finally, the Shougang Industrial Area, to be reused as the Winter Olympic Park, was selected as the case study. The vulnerability analysis results show that the vulnerability assessment method strongly agrees with the actual status and that the assessment results provide a basis for improving the vulnerability of old industrial areas for reuse.

The Short-Term Reliability Assessment of Distribution Network Based on Conditions Dependent Element Failure Rate

2014 ◽  
Vol 716-717 ◽  
pp. 1130-1135
Author(s):  
Guo Xun Yuan ◽  
Song Lin ◽  
Yang Xu ◽  
Can Zhao ◽  
Lei Dong ◽  
...  
Keyword(s):  
Distribution Network ◽  
Reliability Assessment ◽  
Assessment Model ◽  
Assessment Process ◽  
Failure Model ◽  
Temperature Dependent ◽  
Short Term ◽  
Actual Operation ◽  
Dependent Model ◽  
Maintenance Personnel

Specific to the demand for the actual operation, this paper calculates short-term failure rates of various types of elements by adopting improved conditions dependent model: temperature-dependent element aging failure model, weather-dependent occasional failure model, current-dependent overload protection model, and processes a short-term reliability assessment by forward failure diffusion algorithm. Example analysis is simulated by 11kV distribution network of IEEE RBTS Bus-2 system to prove the reliability assessment model, the reliability assessment process are effective and provide on-site operation and maintenance personnel with guidance for decision making in the short-term scheduling and online operation.

scholarly journals Therapeutic Assessment as an Interventional Model of Psychological Evaluation: Case Study

Psico-USF ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 429-438
Author(s):  
Scarlett Borges Fernandes ◽  
Rebeca de Moura Targino ◽  
Fernanda da Fonseca Giasson ◽  
Lucila Moraes Cardoso
Keyword(s):  
Psychological Evaluation ◽  
Assessment Model ◽  
Assessment Process ◽  
Therapeutic Assessment ◽  
Self Reflection ◽  
Therapeutic Consequences ◽  
Therapeutic Benefits ◽  
Self Knowledge ◽  
Difficult Situations

Abstract Therapeutic Assessment is a model of psychological evaluation that adopts a collaborative approach and a semi-structured systematization to the extent that it has well-defined steps. Considering its intervention nature, Therapeutic Assessment seeks to bring about positive changes in the lives of clients and/or people close to them. The present study aimed to evaluate how the Therapeutic Assessment process presented therapeutic consequences, using the case study as a research method. The description of the results was based on the assistance of a client using the Therapeutic Assessment model. The findings corroborate the hypotheses related to the therapeutic benefits of the Therapeutic Assessment, providing the clients with increased self-knowledge and self-reflection and changes in the way they deal with difficult situations. We conclude that more research on Therapeutic Assessment should be developed to verify other possible benefits of the model.

Resource Allocation for System Reliability Analysis Using Accelerated Life Testing

2019 ◽  
Author(s):  
Kassem Moustafa ◽  
Zhen Hu ◽  
Zissimos P. Mourelatos ◽  
Igor Baseski ◽  
Monica Majcher
Keyword(s):  
Resource Allocation ◽  
System Reliability ◽  
Failure Time ◽  
Reliability Assessment ◽  
Accelerated Life Test ◽  
Assessment Process ◽  
System Level ◽  
Component Level ◽  
Accelerated Life ◽  
Failure Time Distributions

Abstract Accelerated life test (ALT) has been widely used to accelerate the product reliability assessment process by testing product at higher than nominal stress conditions. For a system with multiple components, the tests can be performed at component-level or system-level. The data at these two levels require different amount of resources to collect and carry different values of information for system reliability assessment. Even though component-level tests are cheap to perform, they cannot account for the correlations between the failure time distributions of different components. While system-level tests can naturally account for the complicated dependence between component failure time distributions, the required testing efforts are much higher than that of component-level tests. This research proposes a novel resource allocation framework for ALT-based system reliability assessment. A physics-informed load model is first employed to bridge the gap between component-level tests and system-level tests. An optimization framework is then developed to effectively allocate testing resources to different types of tests. The information fusion of component-level and system-level tests allows us to accurately estimate the system reliability with a minimized requirement on the testing resources. Results of one numerical example demonstrate the effectiveness of the proposed framework.

Assessment 360°: A Panoramic Framework for Assessing English Language Learners

2010 ◽  
Vol 17 (2) ◽  
pp. 37-56 ◽  
Author(s):  
Nancy Lewis ◽  
Nancy Castilleja ◽  
Barbara J. Moore ◽  
Barbara Rodriguez
Keyword(s):  
English Language Learners ◽  
Language Learners ◽  
English Language ◽  
Linguistically Diverse ◽  
Assessment Process ◽  
Assessment Practices ◽  
Her Family ◽  
Diverse Student ◽  
Many Sources

This issue describes the Assessment 360° process, which takes a panoramic approach to the language assessment process with school-age English Language Learners (ELLs). The Assessment 360° process guides clinicians to obtain information from many sources when gathering information about the child and his or her family. To illustrate the process, a bilingual fourth grade student whose native language (L1) is Spanish and who has been referred for a comprehensive language evaluation is presented. This case study features the assessment issues typically encountered by speech-language pathologists and introduces assessment through a panoramic lens. Recommendations specific to the case study are presented along with clinical implications for assessment practices with culturally and linguistically diverse student populations.

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