• 대한기계학회논문집B
• /
• 제27권1호
• /
• pp.25-31
• /
• 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.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2010년도 제39회 하계학술대회 초록집
• /
• pp.314-314
• /
• 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.

• 컴퓨터교육학회논문지
• /
• 제3권1호
• /
• pp.1-12
• /
• 2000

최근 리눅스 운영체제가 웹 서버용으로 많이 사용되고 있으나, 웹 서버를 구축하기 위한 여러 가지 소프트웨어의 설치 및 데이터베이스 연동 등의 번거로운 작업들이 필요하다. 특히 국내 초, 중, 고교에서는 학교의 여건상 컴퓨터를 전문적으로 활용하여 웹 서버 구축이나 사이버스쿨을 구축 할 인원도 흔하지 않다. 본 논문은 리눅스 상에서 웹서버 프로그램의 설치와 데이터베이스의 연동 및 웹 프로그래밍 언어를 이용하여 웹 기반 사이버 스쿨을 자동으로 구축해 주는 시스템의 설계 및 구현에 관한 것이다. 이 시스템의 설계 개념은 컨텐츠가 없는 웹 기반 사이버 스쿨의 생성과 컨텐츠의 구축 과정을 분리한 2단계(phase) 구축방법이다. 즉, 몇 개의 명령어로 웹 기반 사이버 스쿨을 구축하고, 컨텐츠는 적재기능(upload)을 이용하여 이미 만들어진 파일을 간단히 적재한다.

• KIEAE Journal
• /
• 제6권3호
• /
• pp.3-10
• /
• 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.

• 한국건설관리학회논문집
• /
• 제13권3호
• /
• pp.14-24
• /
• 2012

최근 세계 건설시장에서의 발주방식은 빠른 속도로 변화하고 있으며, 이에 대한 건설 사업도 대형화 및 고난이도 공사가 증가하고 있다. 이러한 사업의 많은 부분이 설계시공일괄방식 사업으로 발주 되고 있으며, 공사금액기준으로 2009년 국내 조달청 발주공사의 약 40%를 일괄입찰방식(Design-Build)으로 발주를 하고 있다. 반면 설계시공일괄방식 사업의 증가로 그 중요성은 강조되지만, 사업수행자의 사업비용 관리차원에서 기대이상의 성과를 얻지 못하고 있는 실정이다. 그 이유는 사업방식의 특성상, 기본설계 이후 사업 수행계약이 체결되며, 관련 신기술 및 공법 적용에 대한 발주 검토 미흡과 설계과정에서의 불충분한 협의 등으로 사업비용(Cost) 증가에 대한 리스크가 상존하기 때문이다. 이를 해결하기 위해 사업수행 과정에서 사업비용의 증가 원인에 대한 요인을 찾고, 전체 사업 업무단계(Business Process)에서 리스크요인(Risk Factor)에 대한 우선순위 선정과 긴밀한 관리가 필요하다. 따라서 본 연구는 설계시공일괄방식 사업의 특성과 관련한 문제점을 근거로 사업비용에 대한 업무단계별 중요도를 분석하고, 사업수행자 측면의 업무단계별 사업비용 증가에 대한 리스크요인을 도출하여, 그에 대한 영향도(Impact assessment)를 FMEA(Failure Mode and Effect Analysis)기법을 통해 평가하였다.

• 한국컴퓨터정보학회지
• /
• 제1권2호
• /
• pp.73-94
• /
• 1995

본 논문은 유통정보 네트워크 활성화 방안에 대하여 효율적인 NDB(Network Data Base)을 설계하였다. NDB(Network Data Base)의 구조는 논리 구조, 격납 구조, 물리 구조로 형성되어 데이터는 하나의 레코드로서 표현되고 데이터들 간의 관계는 링크로서 표현되었다. 또한 데이터베이스의 논리적 구조를 표현한 자료 구조도(Data Structure Diagram:DSD)가 계층 모델로 나타내었다. 각 노드는 레코드 타입을 나타내었고, 타입들을 연결하는 방향을 지닌 링크, 논리적인 격납 형태로 구성되어 데이터베이스를 설계하는데 물리 매체상 서로 연관성 있게 설계되어 자료의 검색과 억세스 효율에 큰 영향을 미쳤다. 또한 설계된 시스템에 네트워크를 형성하고, 네트워크 표준화를 위해 OSI 환경하에서 POS(Point Of Sale)시스템을 이용하여 효율적인 유통 정보 네트워크를 활성화시켰다.

• 품질경영학회지
• /
• 제42권4호
• /
• pp.591-606
• /
• 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
• /
• 제33권6호
• /
• pp.843-851
• /
• 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.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.587-590
• /
• 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.

• 한국통신학회논문지
• /
• 제30권4A호
• /
• pp.328-335
• /
• 2005

본 논문에서는 내장된 메모리의 자체 테스트를 통한 메모리 고장 유무 확인과 더불어 메인 메모리의 고장난 부분을 여분의 메모리로 재배치하여 사용자로 하여금 고장난 메모리를 정상적인 메모리처럼 사용할 수 있도록 BISR(Build-In Self Repair) 설계 및 구현을 하였다. 메인 메모리를 블록 단위로 나누어 고장난 셀의 블록 전체를 재배치하는 방법을 사용하였으며, BISR은 BIST(Build-In Self Test) 모듈과 BIRU(Build-In Remapping Unit) 모듈로 구성된다. 실험결과를 통해 고장난 메모리를 여분의 메모리로 대체하여 사용자가 메모리를 사용함에 있어서 투명하게 제공하는 것을 확인 할 수 있다.