• 한국전자파학회논문지
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• 제10권1호
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• pp.11-21
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• 1999

AICPS(Advanced Information Communication System)는 다양한 서비스망들을 고속으로 지원하기 위하 여, 내부의 연동망인 고속스위칭패브릭(High Speed Switching Fabric: HSSF)을 중심으로 다양한 서비스 인터페이스 기능 모률이 접속되는 형태를 가진다. AICPS는 크게 정보 서비스 이용자들이 접속되는 서비스 이용자 접속 시스댐(User Access Network Subsystem: UANS) , 정보 제공 센터들을 위한 정보 제공 센터 접속 시스템(Information Delivery Network Subsystem : IONS)으로 구성되며, 여기에 시스템 관리를 위한 단위 시스템 운영관리장치(Local Operations and Management System : LOMS)가 접속된다. 본 고에서는 AICPS를 운영 관리하는 LOMS, LOMS를 AICPS의 HSSF와 연결하기 위한 관리망 접속 서브시스템 (Operational Network Ace랭 Subsystem: ONAS)의 구조에 대하여 설명하고, 이들 사이에 적용된 신뢰도 향상 알고리즘 및 전국 관리망 구축 방법에 대하여 기술한다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2003년도 한국우주과학회보 제12권2호
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• pp.56-56
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• 2003

과학위성 1호의 OBC(On-Board Computer)와 Sybsystem 간, Subsystem간, 또는 위성과 지상국간의 통신이 가능해야한다. 그리고 OBC(On-Board-Computer)나 지상국에서의 위성의 모듈들을 명령(Command)을 통하여 제어할 수 있어야 한다. 또한 모듈들을 원격검침(Telemetry)을 통하여 상태를 확인할 수 있어야 한다. 위에서 언급한 기능을 수행하는 모듈이 바로 Network System이다 과학위성1호에는 총 6개의 Network System이 구현되었다. 각각의 Network System들은 여러 Subsystem들과 연결되어있고, Network System간에 또한 연결되어서 Subsystem간의 통신과 Network System에 연결된 모듈들을 제어하고 상태를 수집한다. 본 연구에서는 과학위성1호 Network System의 구조, 기능, Spec 및 연구 개발 내용을 소개한다.

• 상하수도학회지
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• 제20권1호
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• pp.35-43
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• 2006

Concerns related to protecting, identifying, and isolating of subsystems of a water distribution network have led to the realization of the increased importance of valves in the system. The most important purpose of valves in water distribution systems is to isolate a subsystem due to breakage, maintenance activities, or contamination. A subsystem called segment is isolated by the closure of adjacent valves. Minimizing the pipe failure impact, an efficient algorithm is required to identify adjacent valves quickly. In this paper, an algorithm to identify adjacent valves to be closed to isolate a subsystem from the remainder of a network when a pipe failure is presented. The algorithm is operated on a matrix called the valve location matrix containing the information of valve locations. An application to an existing water distribution system demonstrates the developed algorithm efficiently locates the adjacent valves for the isolation of a broken pipe.

• 한국방재학회 논문집
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• 제9권6호
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• pp.133-141
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• 2009

상수관망의 용수는 수용가가 사용하기에 불편함이 없는 적절한 유량과 압력으로 사용성이 충분히 만족된 상태에서 공급되어야 한다. 상수도 시스템의 수리학적 해석 방법으로 사용되는 Demand Driven Analysis (DDA) 방법은 관망의 수리학적 상태가 변화했을 때 부압이 발생하는 등 비현실적인 결과를 발생시킬 수 있다. Pressure Driven Analysis (PDA) 방법은 비정상상태에서의 압력 및 공급량의 변화를 알기 위하여, 절점수두-용수공급량 관계 (Head-Outflow Relationship, HOR)를 이용하는데, 이는 실측자료의 부족으로 인하여 대부분의 연구에서는 HOR이 가정되어 사용되었다. 본 연구에서는 PDA 분석에서 단점을 가진 HOR 대신, 절점에서 실제 사용성을 만족시키면서 공급이 가능한 용수량인 유효유량을 제안하였다. 그리고 Subsystem이 격리되었을 때 유효유량의 변화를 산정함으로써 격리된 부분의 관망에 대한 영향을 평가하여 이를 Subsystem 중요도 지수(Subsystem Importance Index, SII)로 정의하였다. 이를 위해 최적화 기법 중 하나인 Harmony Search와 상수관망 해석 프로그램인 EPANET을 결합하여 모형을 구축하였다. 제안된 모형을 대규모 상수관망에 적용하였으며, 본 모형은 상수관망의 유지, 보수 시에 관거 혹은 밸브 등의 처리 우선순위 산정 및 상수관망 신뢰도 평가로 활용 가능할 것으로 판단된다. 또한 유효유량산정을 통하여 상수관망이 실제로 사용함에 불편함이 없을 정도로 용수공급이 얼마나 가능한가를 종전에 비하여 보다 정량적으로 산정 가능하다.

• 한국시뮬레이션학회논문지
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• 제8권2호
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• pp.1-11
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• 1999

Advanced information communication processing system mainly consists of network access subsystems and a switching system. This paper provides performance analysis of a typical network access subsystem. The network access subsystem is modeled as a queueing network including a server providing polling services. The arrival process of messages to an input buffer is regarded as a Poisson process. Performance measures such as mean input buffer length and mean waiting time of meassages are obtained through simulation, for it is impossible to calculate the performance measures using an analytical method. Hybrid simulation is used to reduce the variance of estimators. The variance reduction effect on the mean waiting time is reported.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.670-675
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• 1994

Yhis paper describes a fault diagnosis simulation of the Real-Time Multiple Fault Dignosis System (RTMFDS) for forcasting faults in a system and deciding current machine state from signal information. Comparing with other diagnosis system for single fault,the system developed deals with multiple fault diagnosis,comprising two main parts. One is a remotesignal generating and transimission terminal and the other is a host system for fault diagnosis. Signal generator generate the random fault signal and the image information, and send this information to host. Host consists of various modules and agents such as Signal Processing Module(SPM) for sinal preprocessing, Performence Monotoring Module(PMM) for subsystem performance monitoring, Trigger Module(TM) for multi-triggering subsystem fault diagnosis, Subsystem Fault Diagnosis Agent(SFDA) for receiving trigger signal, formulating subsystem fault D\ulcornerB and initiating diagnosis, Fault Diagnosis Module(FDM) for simulating component fault with Hierarchical Artificial Neural Network (HANN), numerical models and Hofield network,Result Agent(RA) for receiving simulation result and sending to Treatment solver and Graphic Agent(GA). Each agent represents a separate process in UNIX operating system, information exchange and cooperation between agents was doen by IPC(Inter Process Communication : message queue, semaphore, signal, pipe). Numerical models are used to deseribe structure, function and behavior of total system, subsystems and their components. Hierarchical data structure for diagnosing the fault system is implemented by HANN. Signal generation and transmittion was performed on PC. As a host, SUN workstation with X-Windows(Motif)is used for graphic representation.

• Journal of Advanced Marine Engineering and Technology
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• 제39권8호
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• pp.863-869
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• 2015

This study analyzed the offshore plant industry and related regulations such as ISO, IEC, and Norsok Standards to develop an integrated network management system (INMS) capable of both on-site and remote management and configuration of IP-based network equipment in offshore plants. The INMS was designed based on actual specifications and POS plans, and a plan of management was verified through an offshore plant engineering company. Various modules such as PAGA interface modules, CCTV, IP-PBX, and HF-radio communication modules were developed for system implementation. Protocol and data design and screen design were followed by framework development and introduction of the automatic satellite communication function.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.305-321
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• 2012

Since Internet Protocol (IP) is the most important protocol in Next Generation Networks (NGNs), 3rd Generation Partnership Project (3GPP) utilizes Session Initial Protocol (SIP) based on IP as the base protocol for negotiating sessions in IP Multimedia Subsystem (IMS). Different from traditional circuit-switched network, in IMS, the media traffic and signaling are delivered through IP transport. The media traffic may affect the signaling efficiency in core network, due to traffic collisions and best effort packets delivery. This paper proposes a novel path-migration mechanism for enhancing the traffic efficiency in integrated NGN-IMS. The simulation results show that the interference and traffic collision can be reduce by applying proposed path-migration mechanism and the signaling efficiency in core network can be improved with higher system capability and voice quality.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1994년도 춘계학술발표회
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• pp.55-67
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• 1994

Studies on the ship's automatic navigation & berthing control have been continued by way of solving the ship's mathematical model but the results of such studies have not reached to our satisfactory level due to its non-linear characteristics ar low speed. In this paper the authors propose a new berthing control system which can evaluate as closely as captain's decision-making by using the FNN(Fuzzy Neural Network) controller which can simulate captain's decision-making by using the FNN(Fuzzy neural Network) controller which can simulate captain's knowledge. This berthing controller consists of the navigation subsystem FNN controller and the berthing subsystem FNN controller. The learning data are drawn from Ship Handling Simulator (NavSim NMS90 MK III) and represent the ship motion characteristics internally According to learning procedure both FNN controllers can tune membership functions and identify fuzzy control rules automatically The verified results show the FNN controllers effective to incorporate captain's knowledge and experience of berthing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.3904-3917
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• 2017

IP multimedia subsystem (IMS) is an open standardized architecture for delivering multimedia service over IP network in a route-agnostic manner. With the increasing popularity of conversational class service, the delivery of a traffic flow with a certain bandwidth demand over a single network path is either not possible or not cost-effective. Multipath transmission is considered to be a promising solution to provide high-quality delivery service. This paper proposes a software defined service overlay network (SDSON) based multipath transmission framework for IMS, which is complementary to existing network architecture. The framework transforms original two-party session negotiation into three-party session negotiation that supports participants to negotiate multipath transmission capacity and path information by signaling message. Based on existing IETF standards, SIP and SDP are scalable to support these functions. Finally, the proposed framework is fully implemented on open source platform and examined by experiments. Experimental results show that multipath-enabled IMS is an effective way to improve the delivery performance of conversational class service.