• 제목/요약/키워드: Small system

검색결과 14,181건 처리시간 0.053초

중소도시 지능형 교통계획(ITS) 사용자 서비스 및 시스템 구축에 대한 연구 (A Research on the Construction of ITS(Intelligent Transport Systems) and User Service in Small Cities)

  • 김용범
    • 대한안전경영과학회지
    • /
    • 제8권5호
    • /
    • pp.151-166
    • /
    • 2006
  • To solve the traffic problems of small cities like Chung Ju City, electronic communications equipment and the introduction of advanced technologies are being used or promoted. Other local areas with developed systems in place are being investigated for applicability. Systems like these will be introduced. This system will embody an organized, efficient transportation and safety system within this study At the moment, to solve the problem of reoccurring traffic in small towns in our country, we must develop an ITS service. We are now in the process of selecting and establishing the most adaptable ITS service to a small city For this purpose, we have studied existing records; taken a poll of the citizens of Chung Ju; examined present traffic conditions, examined road capacities; and reviewed available means of transportation. To accomplish the purpose of a thesis like this, we will research and analyze developed nations' and domestic cities' existing systems, construction and operation. We are in the process of building an ITS System which is the most adaptable to a small city like Chung Ju.

정찰 소형무인기용 20cc급 왕복엔진 개조 개발 (20cc-Class Reciprocating Engine Development for a Small Reconnaissance UAVs)

  • 장성호;구삼옥;신영기;김성남;강유원;윤여일;김진수
    • 한국군사과학기술학회지
    • /
    • 제8권1호
    • /
    • pp.49-55
    • /
    • 2005
  • Due to small and light mission payloads, subsystems and propulsion system, small sized UAVs come to be available for reconnaissance that have been performed by aircraft and huge UAVs. The objective of this study is to develop an efficient propulsion system for small reconnaissance UAVs. A glow engine was modified for an efficient and robust 4-stroke gasoline engine with carburetor, new electronic control unit and lubrication system. Engine modification technique and small engine performance test stand are capable of economical method for military UAVs.

Hadoop Distribute file system에서 Small file을 효과적으로 처리하기 위한 파일 병합 기법 연구 (A File Merging Scheme for Efficient Handling of Small Files in Hadoop Distributed File System)

  • 박종창;윤희용
    • 한국정보처리학회:학술대회논문집
    • /
    • 한국정보처리학회 2013년도 추계학술발표대회
    • /
    • pp.15-17
    • /
    • 2013
  • HDFS(Hadoop Distribute File System)는 대용량 파일 처리를 목적으로 설계 되었으며 현재 이상적인 분산 파일 시스템으로 각광 받고 있다. 이러한 HDFS는 기존 분산파일 시스템과 많은 유사성을 가지고 있으나, Fault Tolerance를 제공하고, 데이터 엑세스 패턴을 스트리밍 방식으로 지원하여 대용량 파일을 효율적으로 저장할 수 있다는 차별성을 가지고 있다. 하지만 실제 HDFS 데이터 집합에는 Small file이 차지하는 비중이 상당히 높으며, 이러한 다수의 Small file 은 데이터 처리에 있어 높은 비용을 초래할 뿐 아니라 Master Node 의 파일 처리 및 메모리 성능에 악영향을 미친다. 따라서 본 논문에서는 HDFS에서 Small file 이 미치는 영향을 분석하고 이러한 문제점을 해결 할 수 있는 로컬 인덱스 파일기반의 파일 병합 기법을 제안한다.

저궤도 위성의 전력 시스템 안정화를 위한 모델링 및 제어 (Stabilization Converter Design and Modeling of LEO Satellite Power Systems)

  • 윤석택;원영진;이진호
    • 한국위성정보통신학회논문지
    • /
    • 제5권2호
    • /
    • pp.29-33
    • /
    • 2010
  • 위성 산업은 상업적 군사적 유용성 등의 특성으로 인해 지속적인 발달이 이루어져 왔다. 이중에서도 위성의 전력 시스템은 위성의 수명에 직접적인 관련을 가지고 있으며, 실제 궤도상에서의 Test가 불가능한 특성을 보인다. 또한 저궤도 소형위성은 전력에 민감하므로, 효과적인 전력의 안정화 및 신뢰성 향상은 중요한 문제이다. 일반적으로 저궤도 위성의 전력은 각 부하의 특성에 따라 변환 및 제어가 이루어진다. 따라서 저궤도위성의 전력 시스템은 일반적으로 여러 단계의 전력 변환을 거치게 되므로, 신뢰성 향상을 위한 1차 및 2차 혹은 그 이상 단계의 Converter의 일반화 모델링 및 안정화를 위한 제어기 설계 및 외란에 의한 영향성의 분석이 요구된다. 본 논문에서는 저 궤도 위성 전력계 시스템의 전력 변환을 위한 Converter의 일반화 모델링을 통해 안정화 설계를 위한 파라미터를 추정하고 이를 통한 신뢰성 향상 및 최적 제어 방법에 대해 알아보기로 한다.

중소기업을 위한 일정 기반의 프로젝트 진도 관리 방안 (A Method of Progress Management of Projects Based on Schedule for Small and Medium Enterprises)

  • 오요셉;김보현;백재용;정소영;최영재
    • 산업공학
    • /
    • 제25권2호
    • /
    • pp.276-282
    • /
    • 2012
  • Earned value management(EVM) based progress management was designed to systematically manage large or huge projects with budget based criteria. For this reason, existed methods of EVM based progress management have a practical difficulty to apply to small and medium enterprises(SMEs) not possessing enough human resource, time, and cost. In other words, SMEs have performed simultaneously many small-sized projects emphasizing more project delivery than project budget. This study focuses on the area of project management applying to many small-sized projects simultaneously conducted by SMEs. Thus, the method proposed in this study is to manage only the progress of projects after removing cost factor in order to reduce man powers required for allocating the budget of projects to their all activities in detail in the stage of project planning. This study reveals that SMEs are able to manage progress of many projects easily and intuitively using the proposed method.

마이크로 컴퓨터와 확률론적 리스크 평가를 통한 가압기 보호계통의 설계 개선 (Improvement of Pressurizer PROV System through Micro-Computer and PRA)

  • Jong Ho Lee;Soon Heung Chang
    • Nuclear Engineering and Technology
    • /
    • 제17권4호
    • /
    • pp.302-316
    • /
    • 1985
  • TMI와 월성 사고 이후 PORV를 통한 Small LOCA는 원자력 발전소 리스크의 중요한 요소로 부각되었다. 본 논문에서는 이 계통을 통한 Pressurizer Surveillance System의 설제와 그에 따른 영향을 확률론적 리스크 평가(PBA) 방법으로 해석하였다. 마이크로 컴퓨터는 계통의 고장(Malfunction)을 공정 확인 방법(Process Checking Method)으로 진단하고 그 진단에 따른 후속 동작(Backup Action)을 자동으로 수행한다. 이러한 개선에 따라 운전원의 빠르고 정확한 판단이 어려웠던 “Spurious Opening”, “Fail to Reclose” 및 “Small Break LOCA” 등의 진상(Symptom) 이 정확히 진단되고, 후속 동작의 자동화로 인하여 인간 실수 확률이 기계적 실수 확률로 감소하게 되었다. 결국. 이러한 개선은 계통의 신뢰도 증가로 Small LOCA 확률의 감소를 가져다 준다.

  • PDF

소형 풍력의 과풍속 보호 장치에 관한 연구 (A study of overspeed-protection furling mechanism of Small Wind Turbine)

  • 김형길;김철호;서영택;오철수
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2007년도 제38회 하계학술대회
    • /
    • pp.959-960
    • /
    • 2007
  • The wind power has been used steadily since long ago, but the importance of it has been faded because of the abundant and convenient fossil energy. Now, due to the energy crisis, experiencing the environmental problems etc, the necessity of using it growing bigger. Because the small wind turbines under a few kW grade has the merits of setting up with low costs by individuals, and get the energy saving effects that, it has the secured, separate markets from the range systems, and the developing of it is continuously proceeding. The small wind turbine system must have the output power regulating system for the over wind speed, to run steadily in the various wind speed environment. In case of the small wind turbine system, to prevent the breaking and for safety, at the over wind speed, additional system is required, and in most cases, output power is restricted by mechanical means. In this paper, the furling system makes the tail and the head move to make the blades to the wind in slanted angle, restrict the output power at the over wind speed. In thesis, small prototype wind turbine is made, and analyzing the output power characteristics at the over wind speed, and to verify, through the logical study and tests.

  • PDF

Exploring small mammal monitoring in South Korea: The debut of the Mostela

  • Hee-Bok Park;Anya Lim
    • Journal of Ecology and Environment
    • /
    • 제47권4호
    • /
    • pp.211-218
    • /
    • 2023
  • Background: Traditional wildlife monitoring has often relied on invasive techniques posing risks to species and demanding substantial resources. To address this, camera traps emerged as non-invasive alternatives, albeit primarily tailored for larger mammals, posing limitations for small mammal research. Thus, the Mostela, an innovative tool designed to overcome these challenges, was introduced to monitor small mammals in South Korea. Results: The Mostela was deployed at two study sites in South Korea, yielding compelling evidence of its efficiency in capturing small mammal species. By analyzing the collected data, we calculated the relative abundance of each species and elucidated their activity patterns. Conclusions: In summary, the Mostela system demonstrates substantial potential for advancing small mammal monitoring, offering valuable insights into diversity, community dynamics, activity patterns, and habitat preferences. Its application extends to the detection of endangered and rare species, further contributing to wildlife conservation efforts in South Korea. Consequently, the Mostela system stands as a valuable addition to the toolkit of conservationists and researchers, fostering ethical and non-invasive research practices while advancing our understanding of small mammal populations and ecosystems.

릴레이 결합 및 검사 자동화 시스템 개발 (Development of automation system for relay assembly and test)

  • 국금환;최동엽
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
    • /
    • pp.606-610
    • /
    • 1991
  • A relay is the one of small electrical components for automobiles and used for industry widely. We have developed the automation system for relay assembly and test to make it improve the productivity and decrease the man power. In order to determine the objective process of automation, we investigated 6 small and medium sized-enterprises and 1 greate sized-enterprise producing relays. And, we selected 2 model enterprises of them. One of the two is the system to develop. The scope of our study is the analyse of the conventional workcell, the determination of the system specification, the design of the system layout, the determination of the system cycle time, the design of the system mechanism, and the development of the controller for the system. We think that the developed system may be solve the technical and the economical problems interrupted efficiential automation of domastic small and medium sized-enterprises, and improve the international competitive power.

  • PDF

랙 & 피니언 기어를 이용한 소형 자동차의 직접 조향 방식에 관한 연구 (Study on the Direct Steering System using Rack and Pinion for Ultra-Small Vehicles)

  • 김순호;강민철
    • 한국정밀공학회지
    • /
    • 제19권1호
    • /
    • pp.127-134
    • /
    • 2002
  • This study present a direct steering system using rack and pinion for ultra-small vehicles. The traditional small vehicles for special use had the limitation of space by reason of short wheel tread. These vehicles has adopted a indirect steering system or a center arm system for steering. The disadvantages of these system were deterioration of gear efficiency and increase of parts. For direct-linkage to both knuckles, steering system is made up of out-side tie rods, tie-rod ends, and gear box. Thus, the proposed system has a minimum number of parts. The experimental results show a maximum efficiency at minimum steering angle and a minimum clearance circle. These effects were accomplished by adopting a Ackerman-Jantaud theory.