• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1494-1503
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• 2018

This paper proposes a novel probabilistic load flow model for power systems integrated with large-scale wind power, which considers the multi-time scale dispatching features. The ramp limitations of the units and the steady-state security constraints of the network have been comprehensively considered for the entire duration of the study period; thus, the coupling of the system operation states at different time sections has been taken into account. For each time section, the automatic generation control (AGC) strategy is considered, and all variations associated with the wind power and loads are compensated by all AGC units. Cumulants and the Gram-Charlier expansion are used to solve the proposed model. The effectiveness of the proposed method is validated using the modified IEEE RTS 24-bus system and the modified IEEE 118-bus system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.265-267
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• 2000

The RMU is a power apparatus which is used in loop network distribution system. This paper considers the development of the hybrid interrupter in RMU which adopts both rotating arc and thermal expansion technology. Because of the operating principle of this device, it has some merit, compared with other interrupter. In this research, the geometric construction of the interrupting techniques are given and experimental results of hybrid interrupter which is developed by new technology is introduced.

• 무역학회지
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• 제44권1호
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• pp.159-175
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• 2019

In China, the government has aggressively led the construction and expansion of airports across China. Upon this opportunity, "Korea-China" network is expected to expand. Therefore this study tried to deduce implications for Incheon International Airport by expansion of "Korea-China" traffic rights. As a result of analyzing the exchange values of traffic rights on the "Incheon~Beijing/Chengdu" routes, it was found that there is a concern that Chinese airlines could make inroads into Korean airline's market. In both routes, Korean airline's market share and passenger demand increased while the sales decreased after expanding traffic rights. On the other hand, Chinese airlines showed an increase in sales and a larger passenger growth than Korean airlines. Therefore it is necessary for the government to expand the traffic rights through detailed route value analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.233-236
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• 1989

This paper deals with the expert system using network configuration and input information composed of protective relays and tripped circuit breakers. This system has knowlegebase independent on network dimension because network representation consists of the type of the matrix. Therefore, the knowlege of network representation is simplified, the space of knowlege is reduced, the addition of facts to the knowlege is easy and the expansion of facts is possible. In this paper, the network representation is defined to system matrix. This expert system based on the system matrix diagnoses normal, abnormal operations of protective devices as well as possible fault sections. The brach and bound search technique is used: breadth first technique mixed with depth first technique of primitive PROLOG search technique. This system will be used for real time operations. This expert system obtaines the solution using the pattern matching in working memory without no listing approach for rule control. This paper is written in PROLOG, the A.I. language.

• 한국신뢰성학회지:신뢰성응용연구
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• 제1권2호
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• pp.121-138
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• 2001

Due to large demand for high speed and great capacity for data transfer, WDM, which uses the wavelength division multiplexing technique, is known as alternative way to satisfy those demand for its flexible network operation and management, easy network expansion with existing networks, and enhancement of efficient data transfer rate. For these reasons, a new high capacity WDM optical communication network plan was established. Therefore, the quality of currently deployed optical cables with 81.6 km in length should be assessed to ensure if high capacity WDM system could be implemented on existing optical cables. Two important characteristic parameters, Transfer Loss and PMD (Polarization Mode Dispersion), were measured to evaluate quality of existing optical cable. Transfer Loss was measured at 0.244 dB per kilometer, which is lower than the design standard value at 0.275 dB/km. The measured PMD value gave at 0.030ps/km, and it, therefore, satisfies the value recommended by ITU-T (International Telecommunication Union-T) of 0.5ps/km. In addition, the transfer characteristic for existing 2.5 Gbps and 10 Gbps system were measured and evaluated, and the results showed that error-free transfer is very much feasible. Computer simulation for DWDM system, which is likely be a future backbone network in Korea, to assess the transfer characteristic using the same condition employed for 2.5 Gbps and 10 Gbps was carried out as well. The simulation verified that a stable network operation and reliable service could be provided.

• 제어로봇시스템학회논문지
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• 제13권12호
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• pp.1198-1206
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• 2007

It is common to use PC or Digital picture frame in stand-alone fashion to view images, movies, or to listen MP3 musics which are considered as multimedia contents, However, such existing methods have weakness for expanding network requirements or augmenting extra data, in such case inevitably requiring external devices. With keeping in mind for such expansion, in this study, we have suggested a new concepts of network module which may utilize an image server for data transmission, in the proposed module, data alarm packet was defined for alerting incoming data from the image server and it became possible to synchronize between the image server and device not only in wired but also in wireless environments through UART. The method consists of a control module for an image server and a synchronization module between the server and the device. We have also tested the feasibility for future commercial usages such as advertisements through performance evaluations.

• 한국통신학회논문지
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• 제22권5호
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• pp.981-989
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• 1997

In this paper, the 5-element active phased array antennas coupled through slotline between elements are designed and fabricated. A recent studies on the active phased array antennas using the transmission line coupling which can be designed to provide strong coupling and the appropriate coupling phase. But this sturucture has limitation of expanding in two dimensions for planar active phased array antennas and distortion of the radiation pattern caused by coupling network. Thus our work proposes the slotline coupling structure asthe broadband coupling network for the active phased array antenna. In experiment, 5-elements active phased array antenas have steering range from -30.deg. to 20.deg. off broadside as the free-running frequencies of end elements are controlled. The overall results show that the proposed slotline coupling structure is suited for the coupling network in the actie phased array antenna system. And the proposed coupling structire solves the expansion problem and eliminates the distortion of the radiation pattern caused by the spurious radiation of the transmission line coupling network. Thus thiscan be expanded to two dimensional coupling network for the planar active phased array antenna system.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 Asia Navigation Conference
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• pp.240-257
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• 2006

In an effort to gain competitiveness, recently many companies are trying to outsource their logistics activities to the logistics specialists, while concentrating on their core and strategic business area. Because of this trend, the third party logistics comes to the fore, catching people's attention, and expanding its market rapidly. Under these circumstances, the third party logistics companies are making every effort to improve their logistics services and to develop an information system in order to enhance their competitiveness. In particular, among these efforts one of the critical parts is the decision support system for effective transportation network planning. To this end, this study has developed an efficient decision support system for an optimal transportation network planning by comprehensively considering the transportation mode, routing, assignment, and schedule. As a result of this study, the new system enables the expansion of the third party logistics companies' services including the multimodal transportation, not to mention one mode of transportation, and also gets them ready to plan an international transportation network.

• 한국ITS학회 논문지
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• 제7권6호
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• pp.92-100
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• 2008

Ad-hoc 네트워크는 중앙의 특별한 관리 체계 없이 기존의 유선 네트워크 또는 기지국을 사용하지 않는 이동 호스트들만으로 구성된 네트워크를 말한다. 최근 Ad-hoc 멀티홉 통신시스템과 같은 확장된 개념의 Ad-hoc 망으로 범위가 넓어지고 있어 QoS에 대한 요구 수준이 증대되고 있다. Ad-hoc 네트워크는 잦은 망 구성의 변화, 라우터의 수, 제한된 사용 자원 등 기존 유선 네트워크와는 다른 특성들을 갖게 된다. 기존의 유선 네트워크에서 사용하던 라우팅 프로토콜들을 무선 ad-hoc 네트워크에 그대로 적용시킨다면 많은 문제점들이 발생하게 된다. AODV 라우팅 프로토콜은 Ad-hoc 네트워크 이동 노드에서 사용할 수 있도록 제안된 라우팅 프로토콜이다. Ad-hoc 네트워크에서 변화하는 네트워크의 토폴로지에서 항상 최적의 경로를 설정하는 AODV 라우팅 프로토콜은 신뢰성 높은 데이터를 제공해 준다. 본 논문에서는 NDIS(Network Driver Interface Specification) 기반의 AODV 라우팅 프로토콜을 이용하여 영상 전송이 성능 저하 없이 동작할 수 있는 시스템을 구현하고 확인하였다.

• 한국정보통신학회논문지
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• 제14권11호
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• pp.2586-2592
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• 2010

최근 소셜네트워크게임은 지인과의 관계에 중점을 두면서 여성 유저들과 40대 이상의 고연령층 유저들을 게임 시장으로 끌어내는 등 이용자층 확대에 큰 기여를 하고 있다. 그래서 소셜네트워크게임에 대한 관심과 산업적 확산이 폭발적인 데 반하여 소셜네트워크게임에 대한 학술적인 연구가 미흡하다. 본 연구는 게임전문가와의 심층면담을 통해 최근 성공한 소셜네트워크게임의 성공요인을 살펴보고 이에 대한 개발 지침을 마련하는데 목적이 있다. 소셜네트워크게임 가운데 상업적으로 성공하고 최고의 이용자 수를 갖고 있는 대표적인 게임인 팝벌을 대상으로 핵심 성공요인을 고찰하였다. 그 결과 사회적 교류, 간단한 인터페이스, 비동기 방식, 도구적 합리성 요인이 도출되었다. 본 연구결과를 통해 성공적인 소셜네트워게임을 개발하기 위한 지침으로 활용 될 것으로 기대된다.