• Title/Summary/Keyword: 추진제어

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The Study of Information System Creation and Internal Audit Controls (정보시스템 구축과 내부 감사 제어에 대한 고찰)

  • 변진식
    • KSCI Review
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    • v.11 no.1
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    • pp.9-17
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    • 2003
  • Along with trends of other countries, the Ministry of Information and Communication in Korea decided to operate an Information System Audit Institution for raising qualify of computer network facilitated in state organ and public institution, and to construct effective construction of information system. The aim of the audit institution is applying it to public information business, establishing an information system audit qualification system, and upbringing Private audit organs. The Ministry of Information and Communication realized that although the demand of information system area audit is explosively expanding, the National Computerization Agency cannot satisfies the demand and realize to have audit control for the information of national business as well. The Ministry of Information and Communication plan to enforce the audit on public information business by correlate with information business. The ministry enforce that the supervisory company has major roll to audit and national import business decided by the Information Promotion Committee is subject to have audit control. Therefore, in this paper, the contents of internal audit among internal/external audit will be presented.

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Analysis Study of Liquid Apogee Engine Plume for Geostationary Satellite (정지궤도위성 궤도전이용 액체원지점엔진의 배기가스 해석 연구)

  • Lee, Chi Seong;Lee, Kyun Ho
    • Journal of Aerospace System Engineering
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    • v.12 no.5
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    • pp.8-15
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    • 2018
  • The geostationary satellite uses a liquid apogee engine, to obtain a required velocity increment to enter a geostationary orbit. However, as the liquid apogee engine operates in the vacuum, a considerable disbursement of exhaust plume flow, from the liquid apogee engine can trigger a backflow. As this backflow may possibly collide with the satellite directly, it can cause adverse effects such as surface contamination, thermal load, and altitude disturbance, that can generate performance reduction of the geostationary satellite. So, this study investigated exhaust plume behavior of 400 N grade liquid apogee engine numerically. To analyze exhaust plume behavior in vacuum condition, the DSMC (Direct Simulation Monte Carlo) method based on Boltzmann equation is used. As a result, thermal fluid characteristics of exhaust plume such as temperature and number density, are observed.

On the Development of Authoritative Representations of Torpedo Systems for Engagement Level Simulation (교전수준 어뢰체계 표준모델 개발 방안 연구)

  • Shin, Ji-Hwan
    • Journal of the Korea Society for Simulation
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    • v.16 no.3
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    • pp.19-28
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    • 2007
  • We considered the authoritative representations of torpedo systems that was the engagement level model to develop system specifications and to analyze operational requirements on concept design phase. The Work Breakdown Structure(WBS) of models was defined about authoritative representations of the torpedo systems. The communication of information among each subsystems and input/output parameters were defined. In the heavy weight and light weight torpedo model, presetter, underwater maneuver, war head, sonar, guidance and control, propulsion subsystem modeling were developed for heavy-weight and the light-weight torpedo systems. The authoritative representations of torpedo systems have similar structures with those of the engineering level models and could be verified via engagement level simulations according to the V&V process in the future.

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Advanced Key Management Architecture Based on Tree Structure for Secure SCADA Communications (안전한 SCADA 통신을 위한 트리 기반의 효율적인 키 관리 구조)

  • Choi, Dong-Hyun;Lee, Sung-Jin;Jeong, Han-Jae;Kang, Dong-Joo;Kim, Hak-Man;Kim, Kyung-Sin;Won, Dong-Ho;Kim, Seung-Joo
    • The KIPS Transactions:PartC
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    • v.16C no.1
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    • pp.37-50
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    • 2009
  • The SCADA(Supervisory Control And Data Acquisition) system is a control system for infrastructure of nation. In the past, the SCADA system was designed without security function because of its closed operating environment. However, the security of the SCADA system has become an issue with connection to the open network caused by improved technology. In this paper we review the constraints and security requirements for SCADA system and propose advanced key management architecture for secure SCADA communications. The contributions of the present work are that our scheme support both message broadcasting and secure communications, while the existing key management schemes for SCADA system don't support message broadcasting. Moreover, by evenly spreading much of the total amount of computation across high power nodes (MTU or SUB-MTU), our protocol avoids any potential performance bottleneck of the system while keeping the burden on low power (RTU) nodes at minimal.

다목적실용위성 2호기의 전력용량 예비설계

  • Jang, Sung-Soo;Lee, Sang-Kon;Jang, Jin-Baek;Park, Sung-Woo;Sim, Eun-Sup
    • Aerospace Engineering and Technology
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    • v.1 no.2
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    • pp.57-65
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    • 2002
  • The Electrical Power System (EPS) shall supply required power to maintain spacecraft and payload during the mission. The EPS sizing are based on space environment, satellite mission and lifetime, and allocated budgets. The type of the primary and secondary power is determined according to satellite design-level and allocated subsystem budgets. The design of EPS has closely related to system and others' subsystems design. To supply the sufficient power to the satellite, the implementation of the larger power source and energy storage is impossible actually. And there will be some problems of the attitude control of the satellite, the handling power capability of the electronic boxes, and launch vehicle selection caused by EPS oversizing. Also, the thermal control is not easy in the space by extra power. And the maintenance of the satellite within the specific orbit from orbit-drag is a big design burden of the thruster. So the various technologies have been developed to optimize the EPS sizing and to operate the power system efficiently.

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Virtual Flight Test for Conceptual Lunar Lander Demonstrator (달 착륙선 개념설계형상 검증모델 가상비행시험)

  • Lee, Won-Beom;Rew, Dong-Young
    • Aerospace Engineering and Technology
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    • v.12 no.1
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    • pp.87-93
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    • 2013
  • The conceptual design lunar lander demonstrator has been developed to use as a test bed for advanced spacecraft technologies and to test a prototype planetary lander capable of vertical takeoff and landing. Size of the lunar lander demonstrator is the same as that of lunar lander conceptually designed, however, the weight of lunar lander demonstrator is designed in 1/6 scale in consideration of gravity difference between moon and earth. The thruster clustering and virtual flight test were performed in the demonstrator fixed on the ground. The demonstrator ground test has been conducted for two months in the test site for the solid motor combustion of the Goheung Flight Center. The purposes of ground test of demonstrator are to demonstrate and verify essential electronics, propulsion system, control algorithm, embedded software, structure and system operation technologies before developing the flight model lander. This paper is described about the virtual flight test including test configuration, test aims and test facilities

Web Service-based SCM Process Execution Using BPM (BPM을 이용한 웹서비스 기반의 SCM 프로세스 실행)

  • Seo, Yong-Won;Choi, Yong-Sun;Jang, Jin-Yong;Bae, Hye-Rim
    • The Journal of Society for e-Business Studies
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    • v.9 no.4
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    • pp.65-83
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    • 2004
  • Keen competence in business environments induces companies to introduce Supply Chain Management (SCM), which is accelerated by emerging information technology. Consequently, supply chain integration requires interacting and information sharing among the companies participating in the supply chain. Web services, platform independent technologies, are recently used for SCM. However, web services themselves do not provide high level supply chain integration. Therefore, the ways to control and manage global processes over supply chain need to be developed. In this paper, we introduce a method of executing and managing supply chain process using Business Process Management (BPM) system. BPM system is a software system to support an efficient execution and management of complex business processes, and it is applied to supply chain processes . The supply chain processes can be regarded network of activities, each of which is served as web service and related to one of the participants. Our approach enables not only efficient managing but also effective monitoring of the process, which can be a good basis for improvement of the processes. For a speedy execution of processes, we provide a method to support decision making in course of executing process by software agents, which are also web services.

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A Study of Network Forensics related to Internet Criminal at UCC (UCC와 관련된 인터넷 범죄에 대한 네트워크 포렌식 연구)

  • Lee, Gyu-An;Park, Dea-Woo;Shin, Young-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.2
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    • pp.143-151
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    • 2008
  • 74% of Internet users use the UCC, and You Tube using firearms in a crime occurred. Internet crime occurred in the online, non-face transaction, anonymous, encapsulation. In this paper, we are studied a Network Forensic Way and a technique analyze an aspect criminal the Internet haying appeared at Internet UCC, and to chase. Study ID, IP back-tracking and position chase through corroborative facts collections of the UCC which used UCC search way study of the police and a public prosecutor and storage way and network forensic related to crimes of Internet UCC. Proof data encrypt, and store, and study through approach control and user authentication so that they are adopted to legal proof data through integrity verification after transmission and storages. This research via the Internet and criminal conspiracy to block the advance promotion, and for the criminal investigative agencies of the Internet will contribute to the advancement forensics research.

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A Study on the Construction of CIS(Cooperative Information System) based on CBD (CBD 기반의 CIS 구성에 관한 연구)

  • Kim, Haeng-Gon;Sin, Ho-Jun
    • The KIPS Transactions:PartD
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    • v.8D no.6
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    • pp.715-722
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    • 2001
  • In recent years, we recognize a new paradigm in the development process:From object oriented development, to the development process which has focused on the use of standard components. In recent years a lot of research related to the component-based development has been done, especially in business domain. but still there are many open and unresolved problems in this area. such as established development process for a distributed environment, formal process, infrastructure for COTS, development and management tool considering maintenance to guarantee a proper treatment of components. It also required a service and an application integration for component. In this paper, we propose cooperative information systems (CIS) that supports component based development. It must address for component based systems to achieve their full potential. We identify a set of CIS organized 3-tier which is a presentation layer, business logic layer and data control layer. We also discuss the specific roles and activities for the layers. we also define the behavior and managed information for business logic layer as core level. As an illustration of the CIS, we present a successful considerations which is widely helpful to user when they make decision in component development and assemble. Also, we expect to component reusability and efficiency in business domain.

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A Study on Quantitative methodology to Assess Cyber Security Risks of EMS (스마트그리드 체제에 따른 EMS의 보안 평가를 위한 정량적 방법론에 관한 연구)

  • Woo, Pil Sung;Kim, Balho H.
    • Journal of Energy Engineering
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    • v.24 no.1
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    • pp.123-131
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    • 2015
  • This paper aims to identify and clarify the cyber security risks and their interaction with the power system in Smart Grid. The EMS and other communication networks interact with the power system on a real time basis, so it is important to understand the interaction between two layers to protect the power system from potential cyber threats. In this study, the optimal power flow(OPF) and Power Flow Tracing are used to assess the interaction between the EMS and the power system. Through OPF and Power Flow Tracing based analysis, the physical and economic impacts from potential cyber threats are assessed, and thereby the quantitative risks are measured in a monetary unit.