• Journal of Positioning, Navigation, and Timing
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• 제10권2호
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• pp.145-151
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• 2021

According to the Korea Augmentation Satellite System (KASS) system milestone, Site Acceptance Test (SAT) has three steps test until the end of the project. SAT#1 is the first time of SAT steps and verify the KASS Reference Station (KRS) and Sub System (S/S) for the monitoring and controllable. After the equipment and software were installed at the Mission Control Center (MCC) with Central Monitoring and Control Simulator (CMS) for the SAT#1, the 1:1 test was progressed when the KRS and S/S are ready to test. SAT#1 has a 10 steps test case and it was progressed each KRS sites. The test was finished throughout the real-time monitoring and the data collection including the data analysis all of the 7 KRS sites. Finally SAT#1 was completed on December 2020 with successfully.

• 인터넷정보학회논문지
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• 제6권2호
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• pp.13-24
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• 2005

컴포넌트 조합을 통한 소프트웨어 개발은 Time-To-Market을 위한 시대적인 흐름이며 소프트웨어의 짧은 생명주기(Lifecycle) 를 극복할 수 있는 방안이다. 그러므로 효과적으로 컴포넌트를 통합하기 위한 기법들이 연구되어 왔다. 그러나 체계적이고 실용적인 기법들의 연구가 미흡하였다. 컴포넌트 통합을 위한 핵심 중에 하나는 통합을 위한 스펙을 어떻게 정의하느냐와 그 통합 스펙을 운영하기 위한 컴포넌트 아키텍쳐를 어떻게 구성하느냐 이다. 본 논문은 특화가 가능한 복합 컴포넌트를 개발하기 위해 컴포넌트 아키텍쳐를 기반으로 컴포넌트간의 조합을 위한 가변성 설계 기법을 제안하며 가변성 중에 컴포넌트간의 메시지의 흐름인 워크플로우(Workflow)에 대한 가변성 설계 기법을 제안한다. 본 기법은 컴포넌트 아키텍쳐 기반의 연결 계약(Connection Contract)을 설계하는 것이 핵심이다. 연결 계약은 컴포넌트의 제공 인터페이스(Provided Interface)를 사용하여 설계하며 이 연결 계약에 의해 동적으로 컴포넌트를 조합하고 특화(Customiztion)할 수 있는 기법을 제공한다.

• 융합보안논문지
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• 제15권7호
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• pp.125-134
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• 2015

이 논문은 한반도 통일이 가시화되고 여건이 조성되어 남북한 군사통합을 추진하게 될 때 무엇을 준비하고 실행해야 하는가를 군사 과제를 중심으로 연구하는데 목적을 두었다. 현 상황에서 남북한 통일의 시기를 예단하기는 제한되나 군사적 폭력을 관리하는 군사통합은 평시부터 준비가 되어 있어야 한다. 만일 군사통합이 실패하면 통일 자체도 위태롭게 되기 때문에 실천적 측면에서 정교한 준비가 요구된다. 이 연구에서는 다음의 주제에 대한 해결방안을 제시하고자 한다. 한반도에 적합한 군사통합의 유형과 전제조건은 무엇인가? 남북한 군사통합 추진 시 군사적 과제는 무엇인가? 이 중 핵심과제와 중요과제는 무엇이고 실천적 측면에서 어떻게 준비되어야 하는가?

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.37-43
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• 2001

New product development has been a key element fur organizational evolution. The bulk of research about new product strategy has focused solely on new product development function itself. This paper investigates cross-functional elements in new product development. More specifically, we suggest that there must exist a fit between new product strategy and value chain strategy. It means that, in order to support new product development activity, there must exist a relevant value chain strategy. We consider three types of integration - internal integration, customer integration, and supplier integration - as strategic elements of value chain strategy. For the case of new product strategy, we consider market newness and product technology unfamiliarity as strategic elements. We also consider two types of learning characteristic, i.e., \\\"fast-adaptive learning\\\" and \\\"slow-adaptive leaning\\\" as control factor. Learning characteristic represents firms organizational capability related with organizational learning. For example, fur fast-adaptive learning case, the effect of integration appears early in time. System dynamics simulation is employed to verify our research framework. The results exhibit that there must exist cross-functional relationships between value chain strategy and new product strategy in order to shorten total development time.al development time.

• 대한기계학회논문집A
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• 제24권11호
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• pp.2804-2811
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• 2000

A Nordsick form opf the multirate integration scheme has been proposed for flexible multibody dynamic systems. It is assumed that vibrational modal coordinates in the equations of motion are treated as fast variables, whereas the relative joint coordinates are treated as slow variables. In the multirate integration, the fast variables are integrated with small step-size, and the slow variables are integrated with larger step-size. The proposed multirate integration method is based on the Adams-Bashforth-Moulton predictor-corrector method and implemented in the Nordsieck vector form. The Nordsieck form of multrate integration method provides effective step-size control and at the same time, inherits the efficiency from the Adams integration method. Simulations of a flexible gun and turret system of the military tank have been carried out to show the effectiveness and efficiency of the proposed method.

• 제어로봇시스템학회논문지
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• 제7권3호
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• pp.269-275
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• 2001

In land navigation applications, two kinds of GPS/DR integration schemes are commonly used; the loosely-coupled integration scheme and the tightly-coupled one. The loosely-coupled integration filter has a simple structure and is easy to implement. When the number of visible satellites is insufficient, however, it cannot calibrate the errors of the DR sensors. On the contrary the tigthly-coupled integration filter can sup-press the growth of the error in the DR output even when the visibility is poor. However, it has larger com-putation load due to the state dimension and is inconsistent because of the variation in the measurement dimension. This paper presents a GPS/DR integration scheme with dual integration mode. During when the number of visible satellites is sufficient, the proposed scheme operates in a loosely-coupled integration mode. When the visibility becomes poor, it is switched into a tightly-coupled integration mode. Consequently, the pro-posed scheme can calibrate the DR sensors even when the visibility is poor. In addition, its computation time remains constant even if the number of visible satellites increases. Field experiment results show that the performance of the proposed integration method is almost similar to that of the tightly-coupled one.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.429-436
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• 2005

This paper presents a precise and stable time integration method for dynamic analysis of vibration or multibody systems. A total system is divided into several subsystems and their responses are calculated separately, while the coupling effect is treated equivalently as constant force during time steps. By using iterative procedure to improve equivalent coupling forces, a precise and stable solution is obtained. Some examples such as a seismic response and multibody analyses were carried out to demonstrate its usefulness.

• 한국항공우주학회지
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• 제31권7호
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• pp.1-8
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• 2003

본 논문은 극초음속 유동과 공력가열 해석에서 나타나는 공기 반응의 수치해석적 특징을 다루고 공기반응을 효율적으로 해석하는 부분 내재적 적분법을 공기반응에 적용하였다. 안정적 계산을 위해 화학반응 자코비안이 필수적임을 밝혔으며 자코비안의 양의 실수 특성치로 인한 수치기법의 경직성은 일반적인 연소반응에 비하여 미약하였다. 공기반응에서 부분 내재적 적분법은 화학종 순서의 종속성이 없었으며 완전 내재적 적분법과 동일한 수렴율과 계산 결과를 보였다. 극초음속 유동해석에 부분 내재적 적분법을 적용하면 전체 연산 시간이 감소되었다.

• 소성∙가공
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• 제8권1호
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• pp.22-28
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• 1999

The explicit and implicit time integration methods are applied effectively to analyze sheet metal stamping processes, which include the forming stage and the springback stage consecutively. The explicit time integration method has better merits in the forming stage including highly complicated three-dimensional contact conditions. By contrary, the implicit time integration method is better for analyzing springback since the complicated contact conditions are removed and the computing time to get the final static state is short. In this work, brief descriptions of the formulation and the factor study for springack simulations are presented. Further, the simulated results for the S-rail and the roof panel stamping processes are shown and discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.453-458
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• 2004

This study proposes a new two-level condensation scheme for the construction of a reduced system. In the first step, the candidate area is selected for the construction of the reduced system by energy estimation in element-level. In the second step, primary degrees of freedom are selected by sequential elimination from the candidate degrees of freedom linked to the selected elements. Numerical examples demonstrate that the proposed method saves the computational cost effectively and provides a reduced system which predicts the eigenvalues accurately. Moreover, the well-constructed reduced system can present the reliable behavior of the structure under arbitrary dynamic loads comparing to that of global system. Time integration in a reduced system can save the computing time remarkably. Through a few numerical examples, the efficiency and reliability of the proposed scheme are verified.