• Annual Conference of KIPS
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• 2009.11a
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• pp.219-220
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• 2009

과학 기술의 발전과 함께 함정에 탑재되는 무기와 각종 장비들은 컴퓨터 시스템에 의해 통제, 조작되는 형태로 변하고 있다. 다수의 장비들에 대한 모니터링 정보를 비롯한 다수의 메시지와 이를 조작하는 다양한 프로세스들을 관리해야 할 필요성이 증가하고 있다. 대규모의 실시간 메시지와 분산 환경의 감시의 일관성을 위해 해외에서는 기술표준화 작업이 진행되고 있으며, 이는 DDS(Data Distribution Service)를 기반으로 구성되고 있다. 본 논문에서는 컴퓨터 시스템에 대한 통제를 위해 OMG의 DDS(Data Distribution Service) 통신 미들웨어와 공개 프로젝트인 Fuse를 이용하여 분산 환경의 모니터링 및 파일 복제 서비스를 제공하는 전투 체계 관리 소프트웨어인 CSIMS를 설계, 구현한다.

• IE interfaces
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• v.13 no.3
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• pp.438-443
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• 2000

In this paper, we suggest a new backorder policy for stockout which is occurred in each regional distribution centers of distribution chain for capital-goods product. In backorder process of backorder policy, minimize expected stockout through the balancing-division module, and has occured stockout is backordering through the emergency supply from central distribution center and regional distribution center. Simulation tests show that our backorder policy is on the decrease of backorder cost and improvement of customer service. Our backorder policy has two important benefit. First, customer service level is improved by realization of minimum stockout. Second, the backorder process by allowance of the same level supply is to decrease system operating cost.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.47-52
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• 2012

DAS(Distribution Automation System) is equipped with several software applications such as service restoration, loss minimization, and protective relay coordination. The software applications of DAS are very sensitive to the amount of section load being carried by a particular section of distribution lines. Moreover, each software application requires a different parameter of the section load according to its purpose. Therefore, This paper proposes a new section load management method using real-time measurement data of the distribution lines. In order to provide accurate data to DAS applications, this method considers section loads in terms of the relationship of power versus time. In order to establish that the proposed method is feasible, a performance-testing simulator was developed, and case studies were conducted for a modified real distribution network.

• Journal of the Korea Society of Computer and Information
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• v.21 no.10
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• pp.77-83
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• 2016

To verify the trustworthiness of messages, public key certificates and certificate revocation list(CRL) has been standardized for vehicular networks. However, timely distribution of large CRLs to vehicles should be more elaborated with low bandwidth utilization from a practical point of view. To address this concern, we propose a CRL distribution scheme using long term evolution(LTE) point-to-multicast transmission, namely the enhanced multimedia broadcast multicast service(eMBMS). The schem is much more resource efficient than the existing unicast CRL distribution schemes for vehicular networks and it allows realizing the regional CRL distribution schemes efficiently in LTE network. By means of ns-3 simulation, we analyze the performance, latency, and execution time of the scheme in terms of varying coverage of the multimedia broadcast multicast service over single frequency network (MBFSN).

• Journal of Industrial Technology
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• v.31 no.B
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• pp.17-21
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• 2011

Since the railway passenger services have been recognized as important factor for success in railway, electrical energy consumption in railway station for high quality service has greatly increased. Furthermore, the number of the private railway station has gradually increased. Therefore, the operation conditions for railway power distribution system is dramatically changed in comparison with the past. So, this paper proposes the optimal construction method for railway power distribution system considering economical efficiency and the reliability of power supply to establish the railway power distribution system standard for the future railway industry.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.262-267
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• 2001

In this study, the Reliability of degraded steam turbine blade was evaluated using the limited fatigue data. The statistical estimation of limited fatigue data implies that some unknown uncertainties which may be involved in fatigue reliability analysis. Therefore, an appropriate distribution in the fatigue strength was determined by the characteristic distribution - linear correlation coefficient, fatigue physics, error parameter. 3-parameter Weibull distribution is the most appropriate distribution to assume for infinite region. The load applied on the blade is mainly tensile. The maximum Von-Mises stress is 219.4 MPa at the steady state service condition. The failure probability($F_p$) derived from the strength-stress interference model using Monte carlo simulation under variable service condition is 0.25% at the 99.99% confidence level.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.4
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• pp.443-457
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• 2015

We consider the M/M/c/c queues in which the customers blocked to enter the service facility retry after a random amount of time and some of idle servers can leave the vacation. The vacation time and retrial time are assumed to be of phase type distribution. Approximation formulae for the distribution of the number of customers in service facility and the mean number of customers in orbit are presented. We provide an approximation for M/M/c/c queue with general retrial time and general vacation time by approximating the general distribution with phase type distribution. Some numerical results are presented.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.288-296
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• 2012

The method proposed by the author is intended for assistance in decision-making (concerning changes of connections) by operators of complex distribution systems during states of malfunction (particularly in the events of malfunctions, for which the consequences encompass extended parts of the network), through designation of connection action scenarios (creating substitute configurations). It is the use by the classifying system working with the co-evolution algorithm that enables the effective creation of substitute scenarios for the Medium Voltage electric power distribution network. The author also completed works concerning the possibility of using cooperation of the evolutionary algorithm and the co-evolutionary algorithm with local search algorithms. The method drawn up may be used in current systems managing the work of distribution networks to assist network operators in taking decisions concerning connection actions in supervised electric power systems.

• The Journal of Society for e-Business Studies
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• v.21 no.1
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• pp.79-90
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• 2016

Autonomous knowledge service, a fully-automated and pervasive service for knowledge acquisition and support based on the power of recent ITs is gaining tremendous interest more and more, as not only the level of users' intelligence increases but also the maturity of IT infrastructure improves. Conventional approaches of knowledge service, however, could not satisfy users because they usually provided undesired knowledge which had been acquired without considering users' want. In other words, knowledge acquisition and distribution were separately performed. This research, therefore, suggests an amended autonomous knowledge service framework by fully-automating the whole phases of knowledge life cycle, from knowledge acquisition to distribution. ASKs, the prototype system of this research, is also implemented by defining and specifying component technologies which constituently compose suggested framework. More user-friendly and applicable way of knowledge service will be derived and facilitated through this research.

• Journal of Digital Convergence
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• v.16 no.7
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• pp.189-198
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• 2018

Automotive parts distribution industry focused on increasing sales by product quality until early 2010, but as competition has recently intensified, each company has become interested in core values such as customer satisfaction, trust and loyalty. Therefore, effect of customer-oriented service mindset should be analyzed for the relationship between service quality and customer satisfaction, trust, and loyalty in this industry. For this, a questionnaire survey was conducted for 342 distributors. Structural equation models were analyzed using AMOS 23.0. Empirical results show service quality has positive effects on customer loyalty, and customer satisfaction and trust mediate between service quality and customer loyalty. The service quality became a key factor to elicit customer satisfaction, trust and loyalty. Following studies, it is expected to enhance service quality focusing on extending region coverages.