• The Journal of Asian Finance, Economics and Business
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• 제7권2호
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• pp.301-308
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• 2020

This study focuses on determining the impacts of organizational culture on the accounting information system and the operational performance of small and medium-sized enterprises in Ho Chi Minh City. The paper is organized in five parts: introduction, literature review, research methodology, research results, and conclusion and policy implications. Based on the samples of 353 respondents working in small and mediumsized enterprises in Ho Chi Minh City, the research employs both qualitative and quantitative methods to find the answers for research questions. Group discussion, which yields final observed variables of the factors of organizational culture is used for qualitative method. Statistics, assessment of the reliability of Cronbach's Alpha scale, exploratory factor analysis (EFA), confirmatory factor analysis (CFA) and structural equation modeling (SEM) are used for quantitative procedure. The results show that mission, involvement and inconsistency in organizational culture positively affect the accounting information system of small and medium-sized firms in Vietnam. In addition, mission, involvement, adaptability and consistency in organizational culture are found to have positive impacts on the firm operational performance. Another finding of the study is that the accounting information system has a positive effect on operational performance of small and medium-sized firms in Vietnam.

• 한국군사과학기술학회지
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• 제15권6호
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• pp.754-760
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• 2012

To improve the efficiency and economics of national defence, the needs for defence M&S systems are greatly increased, but the lack of interoperability and reusability lowers the level of reliability in the existing simulations models. Recently, many research activities have been performed and some conceptual models, such as CMMS, DCMF, and KAMA, were introduced. However, these models don't support the whole process of defence M&S system development nor provide integrated domain knowledge and up-to-date data. In this paper, we analyzed the analysts' guidances and doctrines, which are the basic ingredients for the simulation system development, and proposed a systematic structure for all the defence M&S stakeholders to share the standardized domain knowledge, modeling algorithm and data. This will be a logical bridge between Mission Space and Simulation Space, and provide substantial data sets to build simulation systems.

• 제어로봇시스템학회논문지
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• 제21권7호
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• pp.654-661
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• 2015

Stairs are the most popular obstacles in buildings and factories. To enlarge the application areas of a field robotic platform, stair-climbing is very important mission. One important reason why a stair-climbing is difficult is that stairs are various in sizes. To achieve autonomous climbing of various-sized stairs, dynamic modeling is essential. In this research, an inverse dynamic modeling is performed to enable an autonomous stair climbing. Stair-climbing robotic platform with flip locomotion, named FilpBot, is analyzed. The FlipBot platform has advantages of robust stair-climbing of various sizes with constant speed, but the autonomous operation is not yet capable. Based on external constraints and the postures of the robot, inverse dynamic models are derived. The models are switched by the constraints and postures to analyze the continuous motion during stair-climbing. The constraints are changed according to the stair size, therefore the analysis results are different each other. The results of the inverse dynamic modeling are going to be used in motor design and autonomous control of the robotic platform.

• 한국항공우주학회지
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• 제39권7호
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• pp.660-665
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• 2011

공대공 공대지 가상 공중 교전모의시험이 가능한 가상현실기술이 구현된 가변형 비행 시뮬레이터를 개발하였다. 가변형 비행시뮬레이터의 가변 조종실은 국내에서 운용 중인 F-15K, KF-16, T/A-50 급 기종 모의가 가능하며, 터치형 액정시현기를 활용하여 그래픽 계기를 구현함으로써 누구나 손쉽고 빠르게 기종변경이 가능하다. 조종간과 쓰로틀은 모의기종에 맞게 교체가 가능하며, 외부영상시현장치는 국내최초로 Video See-Through Type HMD를 적용하여 조종사의 몰입감을 최대화 시킬 수 있도록 구성하였다.

• 한국CDE학회논문집
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• 제20권3호
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• pp.221-229
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• 2015

M&S (Modeling & Simulation) based design is widely accepted for the development of the future weapon system with better performance in a cheaper and faster way. Integrated simulation environment (ISE) is needed for the M&S based design. On the ISE, system engineers can not only verify design options but also validate system requirements. In this paper, we propose architectural models of the integrated simulation environment (ISE) which incorporates mission effectiveness M&S (Modeling & Simulation), system performance M&S, the optimization model of integrated performances, digital mockup and virtual prototype. The ISE architectural models may be used to implement the ISE for the development of the future unmanned ground combat vehicle.

• 한국군사과학기술학회지
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• 제19권6호
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• pp.769-778
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• 2016

Technical approach on the modeling, simulation and experimentation methods, which are applied for developing a constructive simulation and engagement experimentation software for supporting light weight torpedo operational tactics study, is introduced. Conceptual modeling for the weapon engagement and simulation entities, mathematical models for the simulation elements, approach for the design of experimentations are described, and screen shots of the software are also presented as some example results of experimentation and analysis. It is found that the simulation and experimentation results are useful to support and fulfill the mission needs and requests. As a consequence, the technical approach is rated to be appropriate to accomplish the dedicated purpose of the simulation and experiments.

• International Journal of Aeronautical and Space Sciences
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• 제3권2호
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• pp.40-45
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• 2002

A radiation analysis is performed for the Ka and Ku-band transponder of the Communications and Broadcasting Satellite (CBS) that is planned for launch into the geo-synchronous orbit. A particular attention is given to calculation of Total Ionizing Dose (TID) for the mission life time of 15 + 3 years. A numerical modeling of the charged particles at the geo-synchronous orbit is undertaken. The charged particles from the modeling are then transported through the mechanical structure and component housings of the transponder. A set of locations are selected for the detailed calculation of TID. The results from the present calculation show that three-dimensional modeling of the component housings as well as the mechanical structure of the spacecraft is requisite in order to acquire a reliable calculation of TID.

• 한국항공우주학회지
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• 제33권2호
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• pp.75-83
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• 2005

NASA와 독일 DLR의 Gravity Recovery and Climate Experiment (GRACE)는 편대비행을 하는 두 개의 저궤도 위성을 이용하여 지구중력장을 측정하는 연구이다. 주요 관측 장비는 위성 사이의 거리를 측정하기 위한 초단파 거리측정기와 비중력 가속도를 측정하기 위한 정전기 방식의 3축 가속도계이다. 기본설계 및 허용오차 분석 등에 활용하기 위하여 정밀한 관측기 시뮬레이션 모델을 개발하였는데, 본 논문에서는 이러한 모델링 기법과 이를 적용한 궤도 및 중력장 추정기법에 관해 살펴보았다.

• Journal of Astronomy and Space Sciences
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• 제28권2호
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• pp.133-141
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• 2011

A satellite power system should generate and supply sufficient electric power to perform the satellite mission successfully during the satellite mission period, and it should be developed to be strong to the failure caused by the severe space environment. A satellite power system must have a high reliability with respect to failure. Since it cannot be repaired after launching, different from a ground system, the failures that may happen in space as well as the effect of the failures on the system should be considered in advance. However, it is difficult to use all the hardware to test the performance of the satellite power system to be developed in order to consider the failure mechanism of the electrical power system. Therefore, it is necessary to develop an accurate model for the main components of a power system and, based on that, to develop an accurate model for the entire power system. Through the power system modeling, the overall effect of failure on the main components of the power system can be considered and the protective design can be devised against the failure. In this study, to analyze the failure mode of the power system and the effects of the failure on the power system, we carried out modeling of the main power system components including the solar array regulator, and constituted the entire power system based on the modeling. Additionally, we investigated the effects of representative failures in the solar array regulator on the power system using the power system model.

• 융합보안논문지
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• 제18권3호
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• pp.133-140
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• 2018

4차 산업혁명의 핵심기술이 드론에도 적용됨에 따라 무인비행체 분야의 성장 잠재력이 매우 크며, 국내 외의 민간과 군사 분야의 활용이 급증하고 있는 추세이다. 드론의 활용 분야가 다양하고 그 기능을 군 작전지원 임무에 활용할 경우에 비용효과 측면에서 우수하고 군사적 활용 가치를 기대할 수 있다. 특히, 공군의 경우에 넓은 면적의 비행기지 내에서 항공기 검사, 군수품 보급, 기지경계, 조류 퇴치 등 다양한 항공작전 지원 임무를 드론으로 대체한다면 군사적 활용 효과가 높을 것으로 예상된다. 본 논문에서는 군 작전지원 임무에 드론을 활용할 수 있는 분야를 발굴하고 그 기능을 수행할 수 있는 드론 추천 절차를 제시하며 데이터 관리 방안을 제시한다. 즉, 민간 분야에서 유사한 임무를 수행하고 있는 드론과 탑재 장비 중에서 군 작전 지원임무에 가장 적합한 제원과 기능을 추천하며, 데이터는 관계형 데이터베이스 방식으로 모델링한다.