• ETRI Journal
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• 제41권3호
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• pp.348-357
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• 2019

Fog radio access network (F-RAN) architectures provide markedly improved performance compared to conventional approaches. In this paper, an efficient genetic algorithm-based content distribution scheme is proposed that improves the throughput and reduces the transmission delay of a F-RAN. First, an F-RAN system model is presented that includes a certain number of randomly distributed fog access points (F-APs) that cache popular content from cloud and other sources. Second, the problem of efficient content distribution in F-RANs is described. Third, the details of the proposed optimal genetic algorithm-based content distribution scheme are presented. Finally, simulation results are presented that show the performance of the proposed algorithm rapidly approaches the optimal throughput. When compared with the performance of existing random and exhaustive algorithms, that of the proposed method is demonstrably superior.

• 전력전자학회논문지
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• 제19권3호
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• pp.240-248
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• 2014

It is DC power that Output of renewable energy being recently developed and researched. Also, demand of DC power will expect to proliferate due to increase of digital load. Thus, DC distribution system providing high quality of power and reliability has emerged as a new distribution system. If the conventional distribution systems are substituted by proposed DC distribution system, the output of renewable energy can be connected with distribution systems under minimum power conversion. Therefore, in the event of connection with DC load, it can construct an efficient distribution system. In this paper, the integrated parallel operation of power conversion module for DC distribution system is proposed. Also, this paper proposed modularization of power conversion devices for DC distribution system and power control for parallel operation of large capacity system. DC distribution system consists of three power conversion modules such as AC/DC power conversion module 2 set, ESS module 1 set. DC distribution system controls suitable operation depending on the status of the DC power distribution system and load. Integrated operation of these systems is verified by simulation and experiment results.

• 한국도서관정보학회지
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• 제33권2호
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• pp.303-321
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• 2002

정부의 범위와 역할이 확대되고 그 활동내용이 다양해지면서 정부차원에서 생산되는 정보량도 지속적으로 증가하게 되었을 뿐만 아니라 정부가 생산한 정보는 국민이 국가정책을 이해하는데 중요한 정보원이 되고 있다. 이에 본 연구에서는 우리나라 정부간행물의 발간정책과 최근 발간경향을 살펴보았으며 정부가 생산한 정도의 합리적 배포체계를 위해 법적 제도적 기술적 측면에서 분석하였다.

• 전기학회논문지
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• 제59권10호
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• pp.1776-1786
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• 2010

Intelligent distribution automation system have total monitoring and control capability. The system covers substation, distribution network, distributed generations and customers at HV system. Various intelligent distribution facilities installed at distribution systems have voltage sensor, current sensor, aging monitoring sensor. Intelligent Feeder Remote Terminal Unit (IFRTU) tied to intelligent distribution facilities process information from facilities and it checks information of fault, power quality and aging of distribution facilities. The information is transmitted to master station through communication line. The master station have remote monitoring system covers substation, distribution network, distributed generations and customers. It also have various application programs that maintain optimal network operation by using information from on-site devices.

• Industrial Engineering and Management Systems
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• 제3권2호
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• pp.134-139
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• 2004

During the last three decades, a few attentions have been paid for investigating the cost distribution for the optimal maintenance problems. In this article, we derive the moment of the discounted cost distribution over an infinite time horizon for the basic age replacement problem. With first two moments of the discounted cost distribution, we approximate the underlying distribution function by three theoretical distributions. Through a Monte Carlo simulation, we conclude that the log-normal distribution is the best fitted one to approximate the discounted cost distribution.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.617-620
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• 2016

국내 농산물 유통분야는 농산물의 유통효율성 제고와 수급 및 가격의 불안정 문제를 해결하기 위해서는 기존의 농산물 유통 단계별 주체별 기능별로 개별적이고 독립적인 유통 및 물류관리 체계의 한계를 극복하고 전체 공급 사슬의 참여주체 간 상품 물류 정보 자금흐름 등에서 통합 연계 협력체계를 바탕으로 수급안정과 물류효율성 제고를 실현할 수 있는 방안 제시가 필요하다. 따라서 본고는 이러한 방안제시의 일환으로 농산물 유통 프로세스 상의 정보 관리 현황과 문제점을 살펴보고, 이를 기반으로 농산물 유통 정보를 통합 연계 체계를 구축할 수 있는 농산물 통합유통정보시스템 구조에 대한 참조 표준 모델 및 정보 구조의 표준화 방안을 제시하고자 한다.

• 유통과학연구
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• 제22권3호
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• pp.83-92
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• 2024

Purpose: With the rapid information distribution of sport-related SNS, sport industry has utilized SNS as technical solution to distribute sport and health-related information. The current study examined the effect of SNS information use for running-specific content on running engagement and psychological well-being. Research design, data and methodology: Data were collected via online survey of participants in marathon events of United States. Descriptive statistics and Chi-square test were conducted to compare demographics and psycho-behavioral outcomes among SNS information users and non-users for running-specific contents. Multivariate hierarchical regression was next employed to examine research hypotheses. Results: A mass-participant running event was used to test seven hypotheses related to the potential role of SNS for running content in promoting running engagement and life satisfaction. In general, findings revealed that use of SNS for running content along with frequency of use can perhaps facilitate running intensity and influence participation in running-related outdoor activities. Furthermore, while overall life satisfaction did not appear to be influenced by use of SNS for running content, there was a demonstrated influence on the individual satisfaction domains. Conclusions: The findings of current study suggest that sport SNS is information distribution media enhancing users' engagement and their six life satisfaction domains. Further implications were discussed.

• Journal of the Korean Data and Information Science Society
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• 제8권2호
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• pp.211-223
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• 1997

We introduce the linear estimators based on order statistics in the three-parameter Weibull distribution and compare the small sample performances of proposed linear estimators in the three- parameter Weibull distribution with an unidentified outlier.

• Journal of the Korean Data and Information Science Society
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• 제15권4호
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• pp.753-758
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• 2004

A generalization of gamma distribution is defined by slightly modifying the form of Kobayashi's generalized gamma function(1991). We define a new extended gamma distribution and study some properties of this distribution.

• Journal of the Korean Data and Information Science Society
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• 제10권2호
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• pp.299-311
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• 1999

In this paper the single and product moments of order statistics of the doubly truncated Rayleigh distribution are studied. Some recurrence relations of order statistics are derived. Using order statistics, also characterization of the Rayleigh distribution are derived.