• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.134-141
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• 2004

This paper addresses development of the conceptual design program of satellite communication system. A database for more than 200 small satellites of LEO which are between 10kg and 200kg was constructed to conduct a sequential process of conceptual design. General parameters based on the database were derived to be able to use for initial design of satellite communication system. The general conceptual design process developed and programed in this work is applicable to micro-class small satellites without regard to mission types. This conceptual design algorithm is consisted of five sequential steps, in which various parameters are defined every phase. These parameters are utilized for conceptual design through database analysis. The validity of an entire design algorithm has been demonstrated via program simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.10
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• pp.952-958
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• 2011

On-board IR calibration device has been developed for calibration of spaceborne image sensor. It is composed of a blackbody to provide two different radiance temperatures, tilt mirror with a function of stow and deploy to view the blackbody during the calibration and on-board calibration control unit to control the function of the blackbody and tilt mirror. In this paper, to guarantee the structural safety of the unit, the structural and thermal analysis including a thermo-elastic analysis for verifying structural safety on the soldered part of chips have been performed. In addition, safety margin of the chips on the PCB obtained from the conventional analytical method has been compared to the results from the FEM analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.4
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• pp.292-299
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• 2017

The KUH-1's Wheel Brake Assembly which is Brake System is an essential component to perform flight mission for pilot. It has function of taxing, differential braking and parking to sustain landing capability. However, the skid and abrasion of tire were occurred in mass-produce operation. Also, if it is occurred on the ground, the flight can not be performed. In this case, the defect is a major cause of the decrease in the operation rate of aircraft. In this paper, the cause of the defect in flight was identified and the failure process was organized. Also, it describes design improvements which was derived from troubleshooting and suggests verification results of flight test.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.6
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• pp.490-497
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• 2017

The Main Landing Gear(MLG) of Rotary Wing Aircraft is an essential equipment in Landing System for pilot to perform a flight mission. It supports the fuselage at ground and absorbs the impact from the ground when landing, thereby, these functions sustain operational capability for pilot and crew. However, the A aircraft caused asymmetry and leakage hydraulic when it was stationed on the ground. Therefore, this paper summarizes pilot comments in operation which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.71-75
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• 2006

This paper describes operation plans for satellite communications system (SATCOM) which is consisted of Ka band communication payload, geostationary satellite control system and communication test earth station system for the communication, ocean and meteorological satellite system (COMS). Also this paper describes the communication service and mission plans by each system of the SATCOM, and configurations and functions of the system interface between each system. Especially this paper proposes operational items, functions and their configuration diagrams, touches their operational plans. This paper describes function definitions, configuration diagram and operation plans of the PCS )Payload Control System) for monitor and control of the communication payload and communication service network of the SATCOM.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.2
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• pp.50-61
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• 2002

This paper - following 'Functional requirement of marine waste cleaning ships and organization of the fleets'[1] - describes on the preliminary conceptual design procedure for the multi-purpose marine waste cleaning system for shallow waters. The working area of this system is Yellow Sea and part of South Sea of South Korea. As the first step, we determined the functional requirements including the daily target of waste collecting. Then, the preliminary conceptual design and general arrangements were carried out. In order to evaluate the safety and efficiency of this designed system, the stability check and the computer graphic simulation were carried out. Finally, the sea trial performance test of integrated systems in Yeosoo ports was performed and the designed system was shown its validity and effectiveness.

• Journal of Korean Library and Information Science Society
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• v.39 no.4
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• pp.125-147
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• 2008

Due to the rapid changes of information environment, the libraries are needed to consider not only analog resources but also digital resources for collection development policy to fit the digital age. However, the libraries have difficulties to build digital collection development policy for collecting and archiving the digital resources because different from the analog resources, characteristics of digital information resources are not contained in physical medium and not allowed ownership but remote access by licensing. Especially, national libraries that have the mission to collect, preserve and transmit knowledge and cultural heritage to the next generation face even more serious challenges. This study intends to figure out the core elements of digital collection development policy through comparison of domestic and overseas national library policies tried to overcome the difficulties.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.98-110
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• 2015

Recently, a validation research of maneuvering and attitude control logics of a spacecraft under a ground condition is getting increase by using operating simulators with compact and precise components. For that, a cold gas propulsion system is generally used for maneuvering and attitude control of spacecraft ground simulators for its simplicity and a high reliability. In the present study, major design parameters of a cold gas propulsion system are derived to meet mission requirements based on conceptual design results of a simulator. And additionally, commercial components with proper specifications are selected for system assembly.

• Journal of the Korean Geographical Society
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• v.51 no.1
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• pp.57-75
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• 2016

University has various resources such as intellectual human resource, spatial resource and facilities, and economic resource. At the same time, universities are, in general, found upon fundamental mission of public service, as well as teaching and research. Recently in Korea, it has been argued that we should make use of such resource of universities in the process of urban regeneration through university-community partnership. Yet, these arguments are lack of concreteness: 'which' kind of resource for 'what' kind of problem, and 'how'. Therefore, this research examined the case of university-community partnership in Japan and tried to find of some implications to Korean society. The reason for examining Japanese case is because Japan has experienced similar problems that Korea face such as aging population, decrease in the number of student, deteriorations of existing urban area; there are respectable amount of similarities between Japan and Korea in political, social and economic context; and because Japan has proceeded regeneration of communities through university-community partnerships.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.22-31
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• 2005

A design study was conducted for a new concept aircraft(Canard Rotor/Wing: CRW) that has the capability of dual mode flight, a rotorcraft and a fixed wing mode. The CRW can show a vertical take off/landing and a high speed/efficiency cruise performance simultaneously. It is not surprising to develop a new sizing code for this class of aircraft because conventional sizing codes developed solely for either the rotary wing or the fixed wing aircraft are not adequate to design a dual mode aircraft operated both by the rotary wing through tip jet effux and the fixed wing lift. Thus, a new design code was developed based on the conventional sizing code by adding some features including rotor performance, duct flow, and engine flow analysis, hence could eventually predict the performance of reaction driven rotor, the flight performance and the flight characteristics. The various design parameters were investigated to find their influences on the flight performance then, a small UAV(Unmanned Aircraft Vehicle) of 1500 lbs class was optimally designed to have minimum weight using the developed sizing code.