• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.28-36
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• 2016

Theoretical model of a variable thrust solid rocket motor with a pintle nozzle was derived. For the chamber pressure control, classical model linearization and proportional-intergral controller was used. And then two types of gain scheduling controller were suggested to imporve controller performance for the non-linear propulsion model. Considering characteristics of systems, control gains were scheduled by chamber pressure or free volume. Step responses of each controllers were compared. As a result, the proper control algorithm about characteristics of variable thrust rocket motor was suggested.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.721-724
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• 2011

A system to pressurize propellants stored in propellant tanks is necessary to feed liquid-propellants into combustion devices at the required pressure and flowrate without having cavitation in turbo-pumps. A pressurization system can be categorized into pre-pressurization stage and main-pressurization stage. This report is regarding to a main-pressurization system. Pressurization methods for propellant tanks are divided into pressurant gas generating method and pressurant gas feeding method. One of pressurant gas generating methods uses the vaporized oxygen gas from cryogenic liquid oxygen and non-flammable gas. In this report, both advantages and disadvantages for pressurization methods and types of pressurization systems are compared. Especially the characteristics and principle of pressurization system using impulsive control strategy applied in launch vehicles are introduced. Additionally the structure, schematics, and specifications of heat exchanger, which is one of main units in pressurization system are also discussed. This paper can be utilized to generate the conceptual requirements and to design preliminary configuration of pressurization system during the development of launch vehicle.

• 정보화사회
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• s.111
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• pp.50-56
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• 1997

ITS는 내용상 공공성을 강하게 띠고 있기 때문에 그 운영의 담당기관은 대부분 중앙부서.지자체.공기업 등 공공기관이어야 하며, ITS장비의 구매는 주문생산방식을 취하게 될 것이므로 ITS 기술개발은 전형적인 정부주도형 연구개발분야라고 할 수 있다. ITS는 지역별 특성에 따라 기능별로 미분화된 독립적인 시스템의 도입 및 구축이 불가피하다. 따라서 독립성이 강한 시스템간의 정보교환방식의 표준화는 이용자의 편익차원에서 매우 중요하다. 이는 시스템의 효율성 제고를 위해서도 핵심적인 사항이므로 ITS 기술의 표준화 추진을 위하여 정부주도의 연구개발이 효과적이라고 할 수 있다.

• Journal of Korean Society of Archives and Records Management
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• v.19 no.3
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• pp.247-270
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• 2019

The transition of the central government system to the cloud-based infrastructure is being conducted as the National Information Resources Service (NIRS, Ministry of the Interior and Safety) attempts to integrate government IT resources. In the early days, the transition was attempted as an infrastructure as a service (IaaS) for the cloud service of HW; however, currently, ithe transition is being converted to software as a service (SaaS) for the service of common business. Typical and common business is a document creation for government service and records management. Document creation is produced on cloud On-Nara system, and such system is deployed to central government agencies from 2015 to 2018, as well as the deployment to local government plans is to be gradually implemented after 2018. Currently, the records management is performed with the cloud RMS system, and such system is distributed to the central government from 2016 to 2018, as well as the dissemination to the local government is scheduled to be carried out, considering the adoption of the On-Nara system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.7-10
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• 2006

In order to inject satellites into a target orbit, launch vehicles should have a precise attitude and control system capable of controlling three axises of pitch, yaw and roll. For launch vehicles, there are two types of attitude control system currently in popular use; the first one is a cold gas method, and the other is a liquid propulsion system using a single and dual property propellant. The purpose of this paper is to analyze the characteristics of thrust control system using said propellant, thereby providing for a rationale for its application to the upper stages of launch vehicles, in terms of the simplicity of the system, economics of structure and operation.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.164-170
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• 2007

In this paper, the development results of electromechanical TVC actuation system is described in the aspect of design, analysis, manufacturing and test. The kinds of prime power for TVC actuation system is classified by the variety of propulsion system of launch vehicle. The electric power by battery is the sole candidate for prime power of TVC actuation system at the view point of feasible domestic infra technologies for the present. The characteristic analysis study is performed between electromechanical and electrohydraulic actuation system with respect to power efficiency, performance and weight efficiency. The electromechanical actuation system has superiority of power and weight efficiency according to less opportunity of power conversion process.

• Corrugated packaging logistics
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• no.57 s.12
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• pp.101-105
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• 2004

기술표준원(산업자원부 소속)은 KS인증(제품인증)과 ISO인증(품질경영$\cdot$환경시스템인증)운영상의 문제점이 있다는 지적이 있어, 심사기관과 기술지도기관을 분리하는 등 동 제도들은 근본적으로 개편하여 종합개선 대책을 수립하여 추진키로 하였음

• Information and Communications Magazine
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• v.14 no.11
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• pp.79-95
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• 1997

본 고에서는 현재 IMT-2000/FPLMTS의 표준화에 대해 가장 적극적으로 추진하고 있는 일본의 차세대 이동통신 연구개발 현황 및 표준화 연구활동에 대해 조사 분석하였다. 일본 이동통신가입자 폭증에 대한 표준화 기관 TTCouncil의 대응책과 차세대 이동통신 시스템에 관한 조사연구회의 활동 결과를 우선소개하고, 표준화 관련 두 기관인 망분야의 TTC와 무선분야의 ARIB에서 추진중인 IMT-2000 표준화 연구조직, 내용 등에 대해서 조사 분석하였다.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.9-18
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• 2013

In this paper, we investigated the satisfaction of incorporation founder through the Startbiz System. We also expected that the research results contribute to draw the development plan of Startbiz System afterward. The satisfaction in the Startbiz System was investigated in four dimensions such as the company establishing service, the website quality, the business promotion environment of the associated organizations, and providing information. The satisfaction appeared for the order of the company establishing service, providing information, the website quality, and the business promotion environment of the associated organizations. It's necessary to improve of the business promotion environment of the associated organizations for activating an incorporation utilizing the Startbiz System.

• Bulletin of the Korean Space Science Society
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• 2002.10a
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• pp.75-75
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• 2002