• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.25-31
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• 2003

Airborne contaminant particles are intruded into optical disk drives(ODD) due to the flow caused by disk rotation and can be adhered to lens or disk surfaces, which causes decrease of laser power and increase of read/write errors. Such a phenomenon can be more serious as the space between the disk and the lens is reduced fur high-density storage devices. The purpose of this paper is to understand design parameters to reduce the particle intrusion into an ODD. Suggestions are made to prevent the particle intrusion that can decrease the stability of an ODD and also prevent the potential heat build-up problem. The sealing effect of drive and the forced injection of clean air (using HEPA filter) into the drive minimizes intrusion of the outside air and dusts in an ODD remarkably. Moreover it is proved by experiments that the installation of a heatproof pad to isolate heat generation part (PCB) from information read/write sections and the forced injection of dust-free air reduce the gas temperature inside the drive as well as the amount of particles intruded.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.314-314
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• 2010

For the optimal design of a tokamak-type reactor, self-consistent determination of a radial build of reactor systems is important and the radial build has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor systems. In a low aspect ratio (LAR) tokamak reactor with a superconducting toroidal field (TF) coil, the shield should provide sufficient protection for the superconducting TF coil and the shield plays a key role in determining the size of a reactor. To determine the radial build of a reactor, neutronic effects such as tritium breeding in the blanket, nuclear heating, and radiation damage to toroidal field (TF) coil has to be included in the systems analysis. In this work, the outboard blanket only is considered where tritium self-sufficiency is possible by using an inboard neutron reflector instead of breeding blanket. The reflecting shield should provide not only protection for the superconducting TF coil but also improved neutron economy for the tritium breeding in outboard blanket. Tungsten carbide, metal hydride such as titanium hydride and zirconium hydride can be used for improved shielding performance and thus smaller shield thickness. With the use of advanced technology in the shield, conceptual design of a compact superconducting LAR reactor with aspect ratio of less than 2 will be presented as a viable power plant.

• The Journal of Korean Association of Computer Education
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• v.3 no.1
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• pp.1-12
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• 2000

Recently, Linux operating system is used for web server environment, but to build web server applications need to be operated many related softwares, such as installing web server, web and database system integration and programming for script language. Most of schools in korea do not have computer specialist for building web server or cyber school. In this paper, we describe design and implementation of an automated building system(AnyBuilder) for cyber school. AnyBuilder build web-based cyber school system, just clicking a few of button and some commands. Especially, it has two phases to build cyber school, one is to generate empty web-based cyber school and the other is to upload contents of lecture.

• KIEAE Journal
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• v.6 no.3
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• pp.3-10
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• 2006

As environmental problems and water-shortage phenomenon become a global issue, many states look for the effective method to use water resources. So, decentralized rainwater management is recognized as a new water management system that rainwater can be infiltrated and used on-site. But it is little difficult to build a park, lake, and forest for evaporating rainwater in city because the land price of city is very high. In order to build an excellent infiltration system for a dwelling and a park in Korea, KICT has developed Linear infiltration system. This infiltration system is consist of first flush treatment, storage and infiltration, overflow control system. These elements are connected closely and working as a combined system. A storm sewer can be changed by the linear infiltration system. This study is to make design guideline using Linear infiltration system in apartment house. So ATV-DVWK-M13, FLL and present condition of Korean rainwater system were analyzed and the guidelines direction were set up. Through this study, a foundation is prepared to build the decentralized rainwater management of apartment house.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.14-24
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• 2012

Recently, a delivery system has been rapidly changed in the global construction market. Also, construction projects are becoming bigger and more technology-intensive. A lot of projects have been delivered by Design-Build(DB) System; from the standpoint of cost, approximately 40% of delivered constructions by a Public Procurement Service were DB in 2009. Nevertheless, the achievement has not surpassed our expectations on management of the project cost. On the characteristic of DB, the reasons why that happens are that projects contract have been signed after the Design Development Stage; the insufficient review about new technology and up-to-date construction methods; a lack of discussion in process of design. Those reasons cause a risk of increasing Cost of the projects. In order to solve these problems, it is desirable to find Cost-increasing factors in promoting the projects and select on the order of priority for Risk-Factor with careful management. Therefore, this study analyzed the weight of each phase of the project on the authority of properties of DB project, and identified Risk-factors which is increasing the cost on the aspect of project management. Based on this analysis, the impact assessment of Risk-factor is evaluated through the Failure Mode and Effect Analysis(FMEA).

• KSCI Review
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• v.1 no.2
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• pp.73-94
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• 1995

In this paper, design of efficient NDB(Network Data Base) for the activation plan of chain information network. The DB structure build up, logical structure, store structure, physical structure, the data express for one's record, and the express using linked in the releation of data. Also express as hierarchical model on the DSD(Data Structure Diagram) from the database with logical structure. Each node has express on record type, the linked in course of connective this type, the infuence have efficent of access or search of data, in the design for connection mutually a device of physical, design for database, and construction a form of store for logical. Also activation of chain information network of efficent, using POS(Point Of Sale) system in OSI(Open Systems Interconnection) environment for network standardization, and build up network a design for system.

• Journal of Korean Society for Quality Management
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• v.42 no.4
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• pp.591-606
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• 2014

Purpose: The purpose of this study is to design an experimental simulation model for evaluating the UGV(Unmanned Ground Vehicle) effectiveness in a small unit combat scenario. Methods: We design and build a simulation model to evaluate the combat effectiveness of UGV in a small unit combat scenario. In order to build a simulation model, we used AnyLogic software tool which has functional advantages to describe agent-based simulation model. As for the combat scenario, we applied the typical engagement of mechanized unit equal or lower than battalion level. Analysis process follows the three phases. 1) Design an agent based conceptual medel in a small unit combat scenario. 2) Build a simulation medel using AnyLogic tool. 3) Analyze the simulation results and evaluate the UGV effectiveness. Results: The UGV effectiveness was measured and presented as a numeric values. Those numeric values were represented as a MOE(Measure of Effectiveness) which was the blue survival ratio. Conclusion: We developed an agent based simulation model which can provide a pattern of change how UGV effectiveness varied depending upon the number of UGV in a small unit combat scenario. We also found that the UGV effectiveness grows in the given scenario as the number of UGV increases.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.843-851
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• 2009

Much work has already been done to control and regulate the worldwide problems caused by climate change, particularly the issues on greenhouse gas (GHG) emissions. Carbon dioxide ($CO_2$), having the highest form of concentration among GHGs composed around 1.0 billion tons of emission, and comprises about 98% of the total emissions from the shipping industry. Korean trade mainly rely on the sea transportation. Korean ship tonnages that was brought about by shipbuilders all over the country, continues to grow annually due to the prevailing demands on goods or material supplies and depicting only a small part of the global maritime activity. Nowadays, new build ships coming from the Korean Shipbuilders are being optimized by hull, structure and appendages design, The operational capability of the propulsion and auxiliary machineries in its maximum capacity to achieve the highest possible efficiencies for energy and onboard power use to mitigate $CO_2$ emissions are continually being done through the help of research and development. In this paper, the energy efficiency design index and anboard power capacity of Korean new build ships have been analyzed with response to data collected by ship types, and its respective fuel consumption in relation to $CO_2$ emission results. In response to climate change convention outcome proposals, the best way for the new build ships to become energy efficient is by lowering its operational speed thru adopting the state of the art diesel propulsion engines, patronizing the best sailing practice to lower the transportation cost on the different sea trade routes also helps in $CO_2$ mitigation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.587-590
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• 2002

Build-to-Order (BTO) capabilities enable manufacturing firms to design, produce, and deliver a high volume of differentiated products that meet specific customer needs in timely manner as well as at close to mass-production prices. Aim of BTO is to simultaneously achieve customer responsiveness, cost efficiency, and high volume production. This paper attempts to define the BTO system and suggests the critical components for its realization. A case study is also described to show the impact of a successful BTO implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.328-335
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• 2005

bIn this paper, built-in self-repair(BISR) is proposed for semiconductor memories. BISR is consisted of BIST(Buit-in self-test) and BIRU(Built-In Remapping Uint). BIST circuits are required not oがy to detect the presence of faults but also to specify their locations for repair. The memory rows are virtually divided into row blocks and reconfiguration is performed at the row block level instead of the traditional row level. According to the experimental result, we can verify algorithm for replacement of faulty cell.