• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2016-2021
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• 2003

This paper deals with a control technique of eliminating the transient vibration with respect to a waist axis of an articulated robot. This control technique is based on a model-based control in order to establish the damping effect on the driven mechanical part. The control model is composed of reduced-order electrical and mechanical parts related to the velocity control loop. The parameters of the control model can be obtained from design data or experimental data. This model estimates a load speed converted to the motor shaft. The difference between the estimated load speed and the motor speed is calculated dynamically, and it is added to the velocity command to suppress the transient vibration. This control method is applied to an articulated robot regarded as a time-invariant system. The effectiveness of the model-based control integrated into the position control loop is verified by simulations. Simulations show satisfactory control results to reduce the transient vibration at the end-effector.

• Journal of the Korean Statistical Society
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• 제26권3호
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• pp.365-382
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• 1997

In this paper we study the behaviors of the generalized Durbin-Watson (DW) statistics when the nonstationary seasonal time series regression model is misspecified. It is observed that when the series is seasonally integrated the generalized DW statistic for the seasonal period order autocorrelation converges in probability to zero while teh generalized DW statistic for the first order autocorrelation has nondegenerate asymptotic distribution. When the series is regularly and seasonally integrated the generalized DW for the first order autocorrelation still converges in probability to zero.

• 산업경영시스템학회지
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• 제37권4호
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• pp.116-125
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• 2014

In this paper, we investigate an inventory and production system in a three-layer supply chain system involving a single supplier, single manufacturer and multiple retailers. Earlier study in this type of supply chain only consider a single raw material in order to produce single item, but we consider raw materials in order to produce multiple items. It is assumed that the cycle time at each stage is an integer multiple of the adjacent downstream stage. We develop an iterative solution procedure to find the order quantity for the multiple items and raw materials that minimizes the supply chain-wide total cost per unit time of the supplier and manufacturer's raw materials ordering and holding, setup and finished items holding, the retailer's ordering and inventory holding. Numerical examples are presented to show that the proposed heuristic gives good performance.

• 대한산업공학회지
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• 제42권2호
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• pp.151-164
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• 2016

In this paper, we deal with a risk analysis for an IPS (Integrated power system) and propose a simulation model combining the fault tree and event tree in order to estimate the system availability and risk level, together. Firstly, the basic information such as operational scenarios, physical structure, safety systems is explained in order to make the fault tree and event tree of the IPS. Next, we propose a discrete-event simulation model using a next-event time advance technique to advance the simulation time. Also the state transition and activity diagrams are explained to represent the relationship between the objects. By numerical examples, the redundancy allocation is considered in order to decrease the risk level of the IPS.

• 인터넷정보학회논문지
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• 제14권3호
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• pp.57-65
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• 2013

최근 정보통신기술의 급속한 발달과 대내 외적 경쟁이 가속화되는 등 환경변화에 대응하기 위해 국내 대학은 통합정보시스템 구축 및 고도화의 필요성 인식과 구축 사업을 추진하고 있는 실정이다. 이에 본 연구에서는 고등교육기관의 통합정보시스템 구축 시 환경요인 측면도 정보시스템 성공요인에 중요한 요인이라고 생각하고, 우리나라 현실에 맞는 환경요인을 도출하고자 국 사립대학 통합정보시스템 현황을 분석하였으며, 이를 기반으로 고등교육기관 통합정보시스템 구축 시 고려해야 할 3가지의 환경요인과 21가지의 세부 측정항목을 도출하고, 이를 통합정보시스템을 구축하고자 하는 대학에 성공적으로 적용하기 위한 방안을 제언하였다. 본 연구결과가 대학들의 통합정보시스템 구축 시 성공적인 통합정보시스템 구축의 기초 자료로 활용되기를 기대한다.

• 토지주택연구
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• 제8권3호
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• pp.113-121
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• 2017

Wirye New Town is constructed as a new complex city with three municipalities. Infrastructure must be managed by administrative districts, but integrated management is also needed when considering the planned identity and efficient management and operation aspects of a new town. The purpose of this study is to establish why the integrated management of infrastructure is needed, to form a consensus of stakeholders and to set priorities of integrated management considering characteristics of each facility. This thesis analyzes the order of priorities for integrated management of the infrastructures in Wirye New Town. The study includes an analytic hierarchy process (AHP) survey that asked 95 local city officials and experts in city planning about important values to consider, such as efficiency, equity, and identity, for the integrated management of infrastructures in Wirye New Town. Another survey requested these same people to identify the priorities for integrated management in terms of different infrastructure types. The results are as follows. Those who were surveyed considered efficiency(0.442) to be the most important value for integrated management. Equity was deemed to be the next most important(0.369), followed by identity(0.190). The second step in the AHP survey revealed that "efficiency of management governance" (0.202) was considered to be the most important, then "equity of infrastructure quality among the sub-regions" (0.155), and finally "efficiency for improvement of quality and quantity of services" (0.133). The results of the survey about the priority for integrated management among infrastructure types and AHP shows that 'specialized facilities', 'Space facilities located in more than two municipalities', and 'linear facilities located in more than two municipalities.' are important.

• 정보처리학회논문지C
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• 제11C권4호
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• pp.485-496
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• 2004

광범위한 인터넷의 보급에 따라 컴퓨터 및 네트워크 시스템의 취약점을 이용한 해커들의 통신 웹을 경유한 공격이 쉽게 되었다. 본 논문에서는 통합 보안관리가 가능한 LISS(Linux-based Integrated Security System)라고 이름 붙여진 통합 보안 시스템을 설계하고 구현한다. 이 시스템은 공개 운영 체제인 Linux에 기반하고 있으며, Linux 기반 서버의 보안관리에 효과적인 공개 보안 도구들로 구성되어 있다. LISS의 성능을 시험하기 위하여 테스트베드를 구성하여 시험한 결과, 구현된 시스템이 네트워크 매퍼로부터 발생되는 모든 공격 패턴들을 포획하는 것으로 나타났다.

• 한국인터넷방송통신학회논문지
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• 제15권1호
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• pp.15-23
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• 2015

본 논문은 지난 2012년 이후 떠오른 개념인 '빅 데이터'의 등장으로 정보보안 환경이 어떻게 변화되고 있는지, 빅 데이터와 관련된 분석 기술을 바탕으로 보안위협으로부터 어떤 통합보안시스템을 구축해야 하는지 제안하고자 한다. 빅 데이터 분야에 대해서는 최근 활용 분야에 대한 연구가 활발히 진행 중이며 APT(Advanced Persistent Threats)와 같은 보안 위협으로부터 보호하기 위해 빅 데이터 기반 통합보안관리시스템에서는 어떤 요구사항이 필요한 지 살펴보고자 한다. 또한, 기존 통합보안관리시스템과 현재 빅 데이터 기반 통합보안관리시스템을 비교 분석하며 한계점은 무엇이며 보완되어야 할 점을 제안하여 개선된 통합보안관리시스템을 제안하고자 한다.

• 대한기계학회논문집A
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• 제28권7호
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• pp.1029-1037
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• 2004

High-speed/precision servomechanisms have been widely used in the manufacturing and semiconductor industries. In order to ensure the required high-speed and high-precision specifications in servomechanisms, an integrated design methodology is required, where the interactions between mechanical and electrical subsystems will have to be considered simultaneously. For the first step of the integrated design process, it is necessary to obtain not only strict mathematical models of separate subsystems but also formulation of an integrated design problem. A two-degree-of-freedom controller described in the discrete-time domain is considered as an electrical subsystem in this paper. An accurate identification process of the mechanical subsystem is conducted to verify the obtained mathematical model. Mechanical and electrical constraints render the integrated design problem accurate. Analysis of the system performance according to design and operating parameters is conducted for better understanding of the dynamic behavior and interactions of the servomechanism. Experiments are performed to verify the validity of the integrated design problem in the x-Y positioning system.

• 한국광학회지
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• 제15권6호
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• pp.555-562
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• 2004

3차원 유한 차분 빔전파 방법의 계산시간 및 수렴성 문제를 해결하기 위해서 implicit와 explicit 방법을 결합하는 복합 방법(hybrid method)을 제안하였다. 방향성 결합기의 결합길이를 결정하는 문제를 대상으로 제안된 방법과 implicit 방정식의 해를 직접 구하는 방법의 계산 시간을 비교하였다. 그 결과 직접 풀이법에 비해 제안된 방식의 계산 속도가 최소 10배 이상 빠름을 확인하였다.