• Title/Summary/Keyword: Service reliability

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Lowering Error Floor of LDPC Codes Using an Improved Parallel WBF Algorithm

  • Ma, Kexiang;Li, Yongzhao;Zhu, Caizhi;Zhang, Hailin;Zhang, Yuming
    • ETRI Journal
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    • v.36 no.1
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    • pp.171-174
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    • 2014
  • In weighted bit-flipping-based algorithms for low-density parity-check (LDPC) codes, due to the existence of overconfident incorrectly received bits, the metric values of the corresponding bits will always be wrong in the decoding process. Since these bits cannot be flipped, decoding failure results. To solve this problem, an improved parallel weighted bit flipping algorithm is proposed. Specifically, a reliability-saturation strategy is adopted to increase the flipping probability of the overconfident incorrectly received bits. Simulation results show that the error floor of LDPC codes is greatly lowered.

A Study on the Influence of Service Quality of Trade Portal Sites on the Export Performance of Korean SMEs (무역포탈사이트 서비스품질(品質)이 중소기업(中小企業) 수출성과(輸出成果)에 미치는 영향(影響)에 관한 연구(硏究))

  • Moon, Hee-Cheol;Lim, Seong-Beom
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.34
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    • pp.135-156
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    • 2007
  • Trade Portal Site(TPS) is one of the essential tools which can make it possible for small and medium enterprises(SMEs) to perform international trade activity more efficiently using newest information and communication technology including the Internet. Therefore, Korean SMEs need to utilize TPS more actively to enhance their export competitiveness. In this context, this article analyzes the determinants of export performances of Korean SMEs in utilizing the service of TPS based on the Service Quality Model. As a result of an empirical research by using regressive analysis, various measures of service reliability such as reliability, empathy, and tangibilities have positive effects on SMEs export performance in utilizing TPS. These results provides many useful implications to the TPS managers, e-trade related government agency, along with managers of SMEs using TPS.

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Service life prediction of CFRP bar for concrete reinforcement based on accelerated degradation tests (가속열화시험에 의한 콘크리트용 탄소섬유 강화플라스틱 바의 사용수명 예측)

  • Kwon, Young-Il;Kim, Seung-Jin;Lee, Hyoung-Wook
    • Journal of Applied Reliability
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    • v.9 no.2
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    • pp.71-80
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    • 2009
  • This paper discusses the service life prediction methods for CFRP bar for concrete reinforcement using accelerated degradation tests. The relationship between performance degradation and the rate of a failure-causing chemical reaction is assumed for the temperature accelerated degradation tests. Methods of obtaining acceleration factors and predicting service life of the CFRP bar using the degradation model are presented.

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Service Quality of Internet Shopping Mall and Consumer Satisfaction (인터넷 쇼핑몰의 서비스품질이 소비자 만족에 미치는 영향)

  • 정경수;박용재
    • The Journal of Information Systems
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    • v.10 no.1
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    • pp.173-195
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    • 2001
  • This study is to suggest plans that can make service quality and consumer satisfaction high in internet shopping mall , categorizing the determinants of service quality of Internet shopping mall and analysing determinants of service quality which can give much effect on consumer satisfaction. Using the survey method, the study gathered data from 115 consumers and students with purchasing experience on the web. The Cronbach alpha reliability coefficient was computed to assess the reliability of the responses to all instruments and factor analyses were performed to determine construct validity. Multiple regression was employed to test the hypotheses of this study. According to our findings, the determinants of service quality which influences consumer satisfaction are tangibles, responsiveness, problem solving and security. Several implications of the study are provided in the paper.

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The Development of Performance Measures in Railway Services (철도서비스 평가를 위한 항목 및 지표의 선정방안)

  • Kim Yeon-Kyu
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.222-231
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    • 2003
  • After the reform of rail industry, a system to evaluate service qualities is required for the continuous improvement of railway service and the strength of competitiveness. This research provides evaluation categories and indices which are considered to be suited to the evaluation of rail service qualities. This study provides 4 categories and 11 indices to assess the rail service qualities: provision-operation interval/average operation speed, reliability-regularity/operation cancellation rate, safety- train usage term/facilities for the weak, client satisfaction- easiness of reserving and purchasing of tickets/comfort of queuing facilities/ kindness of train crews/ pleasantness of trains/provision of information, etc.

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A Study on the Strategy of Internet Business Application to the Conventional Clothes Market (재래의류시장의 e-business 적용 전략 연구)

  • 윤문길;정대영;이신수;이혜영
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.10a
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    • pp.185-188
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    • 2000
  • Dongdaemoon clothes market can make traditional commerce to improve problems which happen to traditional commerce and satisfy between customers and salers through combination among Electronic Commerce which is growing up in 21 centuries place innovation This thesis is focusing on suggesting strategies which practice to let Dongdaemoon clothes market customers and wholesalers, retailers to use Electronic Commerce as strategic skills by analyzing core successful factors for adopting Electronic Commerce in Dongdaemoon clothes market. Adopting Electronic Commerce in Dongdaemoon clothes market when the customer make a reservation and the salers provide the customer with discounting service, the customer was willing to but it. Internet service categories which affect customer's satisfaction are providing lots of product information. This thesis shows providing information made the customer to increase customers's satisfaction degree and buying intention. Also convenience of product research, and reliability in transaction process can enable the customer to increase transaction reliability. These factors are very important in Electronic Commerce. In addition, factors which show customer's suggestion and inconvenience by using best seller information and discounting service board when they buy some items in Dongdaemoon clothes market affect the customer satisfaction degree and satisfaction degree of providing information. However, this thesis is analyzed that reliability of transaction process doesn't affect all successful factors such as product quality, size, online payment system, price reliability.

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Qualitative Assessment for Hazard on the Electric Power Installations of a Construction Field using FMEA (FMEA를 이용한 건설현장 전력설비의 위험성에 대한 정성적 평가)

  • Kim Doo-hyun;Lee Jong-ho
    • Journal of the Korean Society of Safety
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    • v.19 no.4 s.68
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    • pp.36-41
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    • 2004
  • This paper presents an qualitative assessment for hazard on the electric power installations of a construction field using FMEL The power installations have the mission to maintain the highest level of service reliability on the works. The more capital the electric power invest the higher service reliability they plausibly will achieve. However, because of limited resources, how effectively budgets can be allocated to achieve service reliability as high as possible. The assessment typically generates recommendations for increasing component reliability, thus improving the power installation safety. The FMEA tabulates the failure modes of components and how their failure affects the power installations being considered. Tn order to estimate the risks of a failures, the FMEA presents criticality estimation or risk priority number using the severity, occurrence, and detectability. The results showed that the highest components of the risk priority number among components were condenser, transformer, MCCB and LA. And In case of the criticality estimation, the potential failure modes were abnormal temperature rise, insulation oil leakage, deterioration for the transformer, overcurrent for the MCCB and operation outage fir the LA.

Reliability Evaluation Criteria and Multi-Stress Aging Test for Polymer Insulator (폴리머 현수애자의 신뢰성 평가 및 복합가속열화 방법)

  • Park, Hoy-Yul;Kang, Dong-Pil;Ahn, Myeong-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.469-472
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    • 2004
  • There have been numerous accelerated aging laboratory tests for evaluating suitability of polymeric materials and devices. Aging test for materials and its full scale device has been conducted, but poor correlation of aging test such as service experience were observed. Service experience plays a key role in the utility section of composite insulators. A meaningful and reliable accelerated aging test is needed for evaluating composite insulator. During the service these insulators are subjected to aging stress such as humidity, pollution, and electrical field, and erosion and tracking of the weathershed occurs. This paper presents the criteria of reliability evaluation and evaluation facilities for 22.9 kV suspension composite insulator. We adopt the criteria of reliability evaluation consist of two test methods. One is CEA tracking wheel test for examining the tracking and erosion performance of composite insulator. The other is multi-stress aging test for examining effects of environmental factors such as UV, temperature, humidity, etc on composite insulator.

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A Study on the Reliability Index and Customer Density of Distribution System (배전계통의 신뢰도 지수와 수용가 밀도에 관한 연구)

  • Bae, In-Su;Kim, Jin-O
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.9
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    • pp.1646-1650
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    • 2011
  • SAIDI(System Average Interruption Duration Index) is the index that signifies the power quality of customers. SAIDI is also used to know how well utilities operate their systems. The annual interruption time in the areas that consists of widely distributed customers, is generally longer than that in the areas that consists of heavily concentrated customers. The Reliability index of huge system is not necessarily better or worse than that of small system, because SAIDI is irrelevant to the total amount of power sold or the total number of customers. This paper proposes a customer density very relevant to SAIDI. The proposed customer density is used to modify the existing SAIDI to more clearly express the service level of power supply. A modified WSAIDI(weighted SAIDI) can be a useful indicator helping utilities improve the reliability of their systems and customers evaluate the service level of receiving power.

Assessment of Main Management Components for Successful University Foodservice Operations By Using SERVQUAL Model (대학 급식소의 성공적인 운영을 위한 필수관리요소 평가 : 서브퀄모델을 활용한 서비스품질관리 활동 평가)

  • Gwak, Dong-Gyeong;Jang, Hye-Ja
    • Journal of the Korean Dietetic Association
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    • v.3 no.2
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    • pp.123-140
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    • 1997
  • The purpose of this study were to assess main management components that can lead to successful university foodservice operations. Specifically, it was intended to develop the tool which assesses the service quality, management, to assess the difference between customer importance from and perceptions of service quality, to compare management perceptions of customer importances with actual service delivery, and to identify internal problems which affect service quality with the use of gap model. Three types of questionnaires were developed and implemented for customers, foodservice personals and foodservice manager. Assessment tools were developed based on the literature review, SERVQUAL, GAP model, and the pilot study. Through the validity and reliability test, the questionnaires were revised. Questionnaires were distributed to 900 university students, 207 foodservice personnels, and 54 foodservice manager respectively. 831 university students, 177 foodservice personnels, and 48 foodservice manager were responded with a response rate of 92.3%, 85.5%, and 88.8% respectively. Statistical data analysis was completed using the SPSS programs for descriptive analysis, ANOVA. and SNK test. The results of this study can be summarized as follows : 1. In quality service management components, 31 quality service attributes were categorized and named into primary quality, secondary quality, hygiene, empathy, tangibles, reliability, responsiveness, and price by the factor analysis. 2. Importance mean score of customers was 4.02 out of 5, but perception mean score of customers was 2.55. So there was a relative big gap(1.47) between importance and perception scores, especially in three dimensions of responsiveness, primary quality, and hygiene. 3. It showed that customers' mean scores of perceived service quality by dimensions were the following order : price > reliability > secondary quality > hygiene > tangibles > primary quality > responsiveness > empathy. And the perception mean score of rented(2.59) or contracted(2.58) management was significantly higher than that of self-operated(2.48). 4. Customers' importances mean score which internal customers recognize was 4.23 out of 5, but service delivery mean score was 3.85. So there was a little gap(0.39) between management perceptions of customer importances and actual service delivery. 5. In gap model, SERVQUAL score showed -1.47, Gap 1 positive 0.15, gap 2 negative 0.61, and gap 3 was positive 0.19. 6. The internal problems were as follows : (1) The managers of University foodservice perceived well enough the customers' expectation value but their management competency was lacked in terms of responding customer needs, (2) The foodservice staff perceived service performance more highly than service quality specifications.

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