• Journal of the Korea Society for Simulation
• /
• v.27 no.3
• /
• pp.117-129
• /
• 2018

In this paper we will discuss two different layout concepts which can be applied to rail-vehicle assembly factory. The existing system is based on the traditional flow line, and the suggested system is based on the fixed position layout. The main factors which affect on the system performances are the variation of process time, shortage rate of part and the shortage period. Simulation experiments indicate that the fixed position layout is better with respect to the throughput, mean flow time per vehicle and the mean flow time per fleet. Furthermore, the fixed position layout is more robust than the flow line because performance measures are insensitive to the variations of factors.

• 한국정보통신설비학회:학술대회논문집
• /
• 2003.08a
• /
• pp.343-345
• /
• 2003

본 논문에서는 광가입자 액세스망에서 댁내 세대 단자함까지 광케이블이 포설된 FTTH(Fiber To The Home)환경에서 가정내에 광대역 홈서비스를 효과적으로 제공하기 위한 홈게이트웨이 시스템의 배치 및 댁내 배선에 대하여 기술하였다. 본 논문에서는 홈네트워크 구성요소 및 홈게이트웨이 배치 배선 결정 요소를 분석하고, 통신과 방송이 통합된 다양한 멀티미디어 서비스를 효과적으로 제공하기 위하여 주거 형태, 홈네트워크 기술 및 서비스에 따른 FTTH 기반 통합 홈게이트웨이 시스템의 배치 및 홈네트워킹을 위한 배선 방안을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.10a
• /
• pp.371-373
• /
• 2012

항로표지는 선박이 운항하는데 필요한 각종 정보를 제공해 주는 중요한 시설물이다. 과거에는 이러한 항로표지 배치를 설계함에 있어 도상 및 경험에 의한 설계가 주로 이루어져 왔으나, 최근 선박의 대형화 및 물동량 증가와 함께 해역의 복잡성이 상대적으로 증가하면서, 항로표지 배치에 보다 과학적인 설계 기법을 도입해야 할 필요성이 증가하고 있다. 항로표지 시뮬레이터는 우리나라 주요 해역의 지형적, 환경적 특성, 그리고 여기에서 운항하는 선박들의 특성, 해상교통 특성 등을 종합적으로 고려한 시뮬레이션 환경을 항로표지 설계자에게 제공함으로써, 최적의 안전성과 효율성을 가진 항로표지 설계, 항로표지 최적 배치계획 등에 대한 의사결정을 효과적으로 지원할 수 있는 시스템을 의미한다. 이를 위해서는, 기존의 선박운항 시뮬레이터 시스템이 가진 기본적인 기능외에 추가적인 기능 설계가 필요하다. 본 논문에서는 이러한 항로표지 시뮬레이터에 대한 개발 및 구축 계획에 대해서 정리하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2018.10a
• /
• pp.122-125
• /
• 2018

최근 다양한 네트워크 서비스에 대한 수요가 증가함에 따라 Service Function (SF)의 동적 구성을 위한 유연한 모델이 요구된다. Service Function Chaining (SFC)은 일련의 SF로 구성된 새로운 네트워크 서비스 배포 모델을 정의한다. Software Defined Networking (SDN)은 제어 평면을 중앙 집중화함으로써 네트워크 트래픽 제어를 단순화하여 SFC동작에 중요한 역할을 한다. SDN 기반 SFC(SD_SFC)는 SF 장애를 감지하기 위한 모니터링 시스템이 필요하다. 그러나 기존의 모니터링 방식은 모든 SF에 Monitoring Agent(MA)를 배치하기 때문에 높은 시그널링 비용을 가진다. 본 논문에서는 최소한의 SF에 MA를 배치함으로써 시그널링 비용을 줄이는 SFC모니터링 방식을 제안한다. 제안하는 SF selection 알고리즘은 최적화된 SF 집합을 사용하여 오버로드된 SF를 반환하여 MA를 배치한다. 우리는 제안 시스템의 효율성을 평가하기 위해 테스트베드 구현을 통해 실험하였다. 실험 결과에 따르면 우리는 기존 방식에 비해서 시그널링 비용을 59.2% 절감하였다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.6
• /
• pp.792-797
• /
• 2011

This paper discusses the application of a hybrid discretiziation method for the discretization procedure that needs to be included in discrete particle swarm optimization (DPSO) for the problem of allocating PV (photovoltaic) systems onto distribution power systems. For this purpose, this paper proposes a rule-based expert system considering the objective function value and its optimizing speed as the input parameters and applied it to the PV allocation problem including discrete decision variables. For multi-level discretization, this paper adopts a hybrid method combined with a simple rounding and sigmoid funtion based 3-step and 5-step quantization methods, and the application of the rule based expert system proposing the adequate discretization method at each PSO iteration so that the DPSO with the hybrid discretization can provide better performance than the previous DPSO.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.8 no.4
• /
• pp.102-108
• /
• 2004

A layout of regenerative liquid rocket engine using turbo pump has been designed for development of high performance liquid rocket engine. each components of engine system was placed by considering assembly and characteristic. first stage engine system is controled by one plane of axis gimballing and composed of four engine assembly to cluster with launch vehicle. second stage engine system is controled by two plane of axis gimballing and composed of one engine assembly. assembly and disassembly Processes and required program have been developed. various shape of instruments were also developed for carrying out assembly and disassembly process efficiently.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.10a
• /
• pp.162-165
• /
• 2004

A layout of regenerative liquid rocket engine using turbo pump has been designed for development of high performance liquid rocket engine. each components of engine system was placed by considering assembly and characteristic. first stage engine system is controled by one plane of axis gimballing and composed of four engine assembly to cluster with launch vehicle. second stage engine system is controled by two plane of axis gimballing and composed of one engine assembly. assembly and disassembly processes and required program have been developed. various shape of instruments were also developed for carrying out assembly and disassembly process efficiently

• Journal of KIISE:Computing Practices and Letters
• /
• v.9 no.3
• /
• pp.241-253
• /
• 2003

SCA (Software Communication Architecture), which has been adopted as a SDR(Software Defined Radio) Forum standard, provides a framework that successfully exploits common design patterns of embedded systems software. However, the SCA is inadequate as a component framework since it does not explicitly specify (1) a component model that defines how to express a component interface and how to implement it, (2) a package model that defines what and how to package in deployment units, and (3) a deployment model that defines the deployment environment and deployment process. In this paper, we propose a SCA-based component framework for SDR. Specifically, we present (1) a component model that defines a component as a specialized CORBA object that implements object management functionality, (2) a package model exploiting the existing XML descriptors of the SCA, and (3) a deployment model that defines a SCA-based deployment environment, a boot-up process that restores the deployment state, and a deployment process that supports lazy application instantiation and dynamic component replacement.

• Journal of IKEEE
• /
• v.22 no.3
• /
• pp.658-663
• /
• 2018

In this paper, we consider node deployment algorithms for the sequence-based localization (SBL) which is recently employed for in-door positioning systems, Whereas previous node selection or deployment algorithms seek to place nodes at centrold of the region where more targets are likely to be found, we observe that the boundaries dividing such regions can be good locations for the nodes in SBL systems. Motivated by this observation, we propose an efficient node deployment algorithm that determines the boundaries by using the well-known K-means algorithm and find the potential node locations based on the bi-section method for low-complexity design. We demonstrate through experiments that the proposed algorithm achieves significant localization performance over random node allocation with a substantially reduced complexity as compared with a full search.

• Journal of Intelligence and Information Systems
• /
• v.13 no.2
• /
• pp.55-68
• /
• 2007

DNA sequence alignment algorithms in computational molecular biology have been improved by diverse methods. In this paper, we proposed a DNA sequence alignment algorithm utilizing quality information and a fuzzy inference method utilizing characteristics of DNA sequence fragments and a fuzzy logic system in order to improve conventional DNA sequence alignment methods using DNA sequence quality information. In conventional algorithms, DNA sequence alignment scores were calculated by the global sequence alignment algorithm proposed by Needleman-Wunsch applying quality information of each DNA fragment. However, there may be errors in the process for calculating DNA sequence alignment scores in case of low quality of DNA fragment tips, because overall DNA sequence quality information are used. In the proposed method, exact DNA sequence alignment can be achieved in spite of low quality of DNA fragment tips by improvement of conventional algorithms using quality information. And also, mapping score parameters used to calculate DNA sequence alignment scores, are dynamically adjusted by the fuzzy logic system utilizing lengths of DNA fragments and frequencies of low quality DNA bases in the fragments. From the experiments by applying real genome data of NCBI (National Center for Biotechnology Information), we could see that the proposed method was more efficient than conventional algorithms using quality information in DNA sequence alignment.