• Title/Summary/Keyword: reliability of distribution system

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A Study on the Outages Due to Voltage Expanding in Closing High Voltage Capacitor (고압 커패시터 투입시 전압확대에 따른 사고 사례 연구)

  • Cho, Nam-Hoon;Jung, Jum-Soo;Park, Yong-Woo;Ha, Bok-Nam;Lee, Hyung-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.9
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    • pp.94-102
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    • 2008
  • Capacitor switching is essential for the economic operation and proper voltage control of KOREA electric utility distribution system. Voltage transients produced by capacitor switching (around 2.0 per unit at substation and 2.5 or less per unit at customer site, and lasting less then 1[ms]) do not have the magnitude or duration to interfere with the operation of computers, but they do disrupt the operation of adjustable speed drivers. The result of our research, ASD manufacturers should learn from the computer industry and design products that will operate satisfactory In the electrical envelopment in which they will be placed. In this case history, the inductors on the input to ADSs in order to prevent nuisance tripping from capacitor switching(and other causes within the apartment) proved to be an effective, low-cost solution.

An Empirical Study on Factors Affecting an Individual User's Behavioral Intention to Use SaaS (개인 사용자의 SaaS 사용의도에 영향을 미치는 요인에 관한 실증적 연구)

  • Hong, Il-Yoo;Lee, Seung-Min;Cho, Hwi-Hyung
    • Informatization Policy
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    • v.25 no.3
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    • pp.75-94
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    • 2018
  • Today, Software as a Service(SaaS) is being recognized as a key means to enable the innovation of software distribution. Despite the increase in the interest in SaaS, individuals as well as businesses are not yet making an extensive use of it. This research is aimed at identifying and analyzing the antecedents of intentions to use SaaS. We proposed a research model to predict an individual's intention to use SaaS based on the Technology Acceptance Model(TAM). To this end, we conducted a questionnaire survey in which actual software users participated. An empirical analysis has been performed to test the reliability and validity and the hypotheses using SPSS and AMOS software packages. The results of the analysis revealed that functionality, interoperability and economic benefits have positive effects on the intention to use SaaS, while system quality has no significant effect on the behavioral intention. We discussed practical as well as academic implications, and provided research directions.

A Study on the Structural Relationship between SCM Activity and Process Innovation, and Quality Performance in SMEs (중소기업의 SCM활동과 프로세스 혁신 및 품질성과 간의 구조적 관계 분석)

  • Lee, Seol-Bin
    • The Journal of the Korea Contents Association
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    • v.19 no.2
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    • pp.170-185
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    • 2019
  • This study is intended to look into the structural relationship between SCM activity, process innovation and quality performance in small and medium sized enterprisers(SMEs). To achieve this, a survey was empirically carried out to 354 SCM operating officers and managers who perform the SCM activities in small and medium sized manufacturing firms. The results are summarized as follows. Overall, the SCM activity and process innovation had a significant effect on the quality performance, having a structural relationship with the quality performance in SEMs. This implies that the strategic alliance of the SCM activities and competence concentration based on technology development in SEMs can organize the unity through organizational members' information sharing. In other words, when the information integration supports the compatibility and reliability of shared information system by raising technological competence through this, the process innovation can lead to non-financial cost reduction, product quality, delivery compliance and inventory cost reduction as quality performance of the structured process, management and distribution.

Parallelization of Genome Sequence Data Pre-Processing on Big Data and HPC Framework (빅데이터 및 고성능컴퓨팅 프레임워크를 활용한 유전체 데이터 전처리 과정의 병렬화)

  • Byun, Eun-Kyu;Kwak, Jae-Hyuck;Mun, Jihyeob
    • KIPS Transactions on Computer and Communication Systems
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    • v.8 no.10
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    • pp.231-238
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    • 2019
  • Analyzing next-generation genome sequencing data in a conventional way using single server may take several tens of hours depending on the data size. However, in order to cope with emergency situations where the results need to be known within a few hours, it is required to improve the performance of a single genome analysis. In this paper, we propose a parallelized method for pre-processing genome sequence data which can reduce the analysis time by utilizing the big data technology and the highperformance computing cluster which is connected to the high-speed network and shares the parallel file system. For the reliability of analytical data, we have chosen a strategy to parallelize the existing analytical tools and algorithms to the new environment. Parallelized processing, data distribution, and parallel merging techniques have been developed and performance improvements have been confirmed through experiments.

An Enhanced System of Group Key Management Based on MIPUF in IoT (IoT 환경의 MIPUF 기반 그룹키 관리 시스템 개선)

  • Tak, Geum Ji;Jeong, Ik Rae;Byun, Jin Wook
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.29 no.6
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    • pp.1243-1257
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    • 2019
  • With the emergence of the IoT environment, various smart devices provide consumers with the convenience and various services. However, as security threats such as invasion of privacy have been reported, the importance of security issues in the IoT environment has emerged, and in particular, the security problem of key management has been discussed, and the PUF has been discussed as a countermeasure. In relation to the key management problem, a protocol using MIPUF has been proposed for the security problem of the group key management system. The system can be applied to lightweight IoT environments and the safety of the PUF ensures the safety of the entire system. However, in some processes, it shows vulnerabilities in terms of safety and efficiency of operation. This paper improves the existing protocol by adding authentication for members, ensuring data independence, reducing unnecessary operations, and increasing the efficiency of database searches. Safety analysis is performed for a specific attack and efficiency analysis results are presented by comparing the computational quantities. Through this, this paper shows that the reliability of data can be improved and our proposed method is lighter than existing protocol.

A Study on Mice Exposure Dose for Low-dose Gamma-irradiation Using Glass Dosimeter (유리선량계를 이용한 저선량 방사선의 마우스 피폭선량 연구)

  • Noh, Sung Jin;Kim, Hyo Jin;Kim, Hyun;Jeong, Dong Hyeok;Son, Tae Gen;Kim, Jung Ki;Yang, Kwangmo;Nam, Sang-Hee;Kang, Yeong-Rok
    • Journal of Radiation Protection and Research
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    • v.40 no.4
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    • pp.202-210
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    • 2015
  • The low dose radiation is done for a long period, thus researchers have to know the exact dose distribution for the irradiated mouse. This research has been conducted in order to find out methods in transmitting an exact dose to mouse in a mouse irradiation experiment carried out using $^{137}Cs$ irradiation equipment installed in the DIRAMS (Dongnam Institution of Radiological & Medical Sciences) research center. We developed a single mouse housing cage and shelf with adjustable geometric factors such as distance and angle from collimator. The measurement of irradiated dose showed a maximal 42% difference of absorbed dose from the desired dose in the conventional irradiation system, whereas only 6% difference of the absorbed dose was measured in the self-developed mouse apartment system. In addition, multi mice housing showed much difference of the absorbed dose in between head and body, compared to single mouse housing in the conventional irradiation system. This research may allow further research about biological effect assessment for the low dose irradiation using the self-developed mouse apartment to provide more exact doses which it tries to transmit, and to have more reliability for the biological analysis results.

Application of SWAT Model considering Spatial Distribution of Rainfall (강우의 공간분포를 고려한 SWAT 모형의 적용)

  • JANG, Daewon;KIM, Duckgil;KIM, Yonsoo;Choi, Wooil
    • Journal of Wetlands Research
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    • v.20 no.1
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    • pp.94-104
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    • 2018
  • In general, the rainfall-runoff simulation is performed using rainfall data from meteorological and observational rain gauge stations. However, if we only use rainfall data from meteorological and observational rain gauge stations for runoff simulation of a large watershed, the problem in the reliability of the simulated runoff can be occurred. Therefore, this study examined the influence of the rainfall data on the simulated runoff volume by a Semi-distributed model. For this, we used rainfall data from meteorological stations, meteorological and observational stations, and a spatially distributed rainfall data from hypothetical stations obtained by kriging method. And, we estimated the areal rainfall of each sub-basin. Also the estimated areal rainfall and the observed rainfall were compared and we compared the simulated runoff volumes using SWAT model by the rainfall data from meteorological and observational rain gauge stations and runoff volume from the estimated areal rainfall by Kriging method were analyzed. This study was performed to examine the accuracy of calculated runoff volume by spatially distributed areal rainfall. The analysis result of this study showed that runoff volume using areal rainfall is similar to observed runoff volume than runoff volume using the rainfall data of weather and rain gauging station. this means that spatially distributed rainfall reflect the real rainfall pattern.

A Study on the Interface between DAS and SCADA by using Direct Method (직접연계방법에 의한 DAS-SCADA 연계 연구)

  • Park, So-Young;Shin, Chang-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.5
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    • pp.1154-1163
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    • 2008
  • DAS and SCADA system are main systems, which operate and manage the power system by using computer and communication technology. But DAS and SCADA have been operated independently in Korea, so there was some time delay in the fault handling and live-line work. To improve that problems, studies on the interface between DAS and SCADA have been needed. From November 2005 to December 2007, the pilot project has been performed in KEPCO's branch offices, as a result, direct method will be applied widely all over the country until 2010 because the operation information of substation users want can be transmitted fast and it is possible to control 43RC directly although the expense for direct method is about 1.3 times larger than that for web method. To improve problems revealed during the pilot project, substation object to object communication method is proposed and interface database automatic generation and interface system diagnosis and logging functions are developed. Interface data point and communication data type are defined, substation single line diagram automatic generation or manual editing function, SCADA monitoring and controlling function, log data managing function are developed in SCADA HMI program. It is expecting to reduce the average time for each outage about 33% and to improve the reliability, efficiency of operation, execution of DAS from automatic load transfer under a fault, and to contribute to export project.

A Study on the Application of Block Chain Technology on EVMS (EVMS 업무의 블록체인 기술 적용 방안 연구)

  • Kim, Il-Han;Kwon, Sun-Dong
    • Management & Information Systems Review
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    • v.39 no.2
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    • pp.39-60
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    • 2020
  • Block chain technology is one of the core elements for realizing the 4th industrial revolution, and many efforts have been made by government and companies to provide services based on block chain technology. In this study we analyzed the benefits of block chain technology for EVMS and designed EVMS block chain platform with increased data security and work efficiency for project management data, which are important assets in monitoring progress, foreseeing future events, and managing post-completion. We did the case studies on the benefits of block chain technology and then conducted the survey study on security, reliability, and efficiency of block chain technology, targeting 18 block chain experts and project developers. And then, we interviewed EVMS system operator on the compatibility between block chain technology and EVM Systems. The result of the case studies showed that block chain technology can be applied to financial, logistic, medical, and public services to simplify the insurance claim process and to improve reliability by distributing transaction data storage and applying security·encryption features. Also, our research on the characteristics and necessity of block chain technology in EVMS revealed the improvability of security, reliability, and efficiency of management and distribution of EVMS data. Finally, we designed a network model, a block structure, and a consensus algorithm model and combined them to construct a conceptual block chain model for EVM system. This study has the following contribution. First, we reviewed that the block chain technology is suitable for application in the defense sector and proposed a conceptual model. Second, the effect that can be obtained by applying block chain technology to EVMS was derived, and the possibility of improving the existing business process was derived.

Antecedents and Consequences of Cooperation in Retail Voluntary Chain (소매점 볼런터리 체인 활성화의 선행요인과 결과)

  • Yi, Ho-Taek
    • Journal of Distribution Science
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    • v.14 no.6
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    • pp.65-73
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    • 2016
  • Purpose - Recently, the management conditions of small independent retailers are getting worse everyday as large-scale marts and franchised convenience stores are increasing. The objective of this research is to find out the antecedents and consequences of cooperation in voluntary chain in order to enhance small independent retailer's competitiveness. Voluntary chains, also called affiliation or symbol groups, or allied group represent a high market shared in some European countries like Italy, France, and Germany. Nevertheless, there are still limitations in this research from academic fields. Drawing from network theory, the author investigates the relationship between antecedent factors in voluntary chain cooperation, such as participation benefits, justice of compensation, and autonomy in voluntary chain, and relationship specific asset. The author also attempts to examine the relationship between the relationship specific asset and cooperation of voluntary chain member shop and cooperation and consequence factors of voluntary chain cooperation, such as efficiency, group cohesiveness, and long-term relationship. Research design, data, and methodology - The author presented conceptual framework integrating the major antecedents and consequences of voluntary chain cooperation. The data were collected from 174 independent small retailers who joined K-voluntary chain. K-voluntary chain consists of small independent retailers. In accordance with their status, each entrepreneur associated with the voluntary group can own one or more outlets and can be a part of the life and the decision-making process of the group. This participation is not based on company turnover or on the number of outlets, but based on a one member, one vote system. To verify the research model and test hypotheses, the author carefully investigated the reliability, content validity, convergent validity, and discriminant validity of the proposed model. The data were analyzed by using SPSS 18.0 and AMOS structural equation modeling program. Results - The results of this study are as follows. First, as antecedent variables, participation benefits and justice of compensation have positive effect on the relationship specific assets of voluntary chain members. Second, voluntary chain members' relationship specific asset also directly related to the level of its cooperation to chain headquarter. Third, cooperation of voluntary chain member shop facilitates efficiency, group cohesiveness, and long-term relationship. Unexpectedly, there are no effect autonomy in voluntary chain to relationship specific asset. Conclusions - This research shows several theoretical and practical implications to both marketing scholars and marketers. In terms of theoretical implications, this study applies to network theory and network theory variables to explain the antecedent and consequence factors of cooperation in voluntary chain. From the point of view from business management, most of all, this study shows the way how to reinforce competitiveness of voluntary chain. Specifically, it is necessary for voluntary chain headquarter to give higher level of participation benefit and justice of compensation to its members. Second, the results also indicate what the consequence factors of cooperation in voluntary chain. In other words, to increase the level of marketing efficiency, group cohesiveness, long-term orientation in retail voluntary chain, and chain headquarter need to facilitate participants' cooperation.