• 제목/요약/키워드: Up-down construction

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데이터 웨어하우스 구축을 위한 상향식.하향식 접근 방법에 관한 연구 - 방법론적 고찰을 통한 접근

  • 박주석;전대성;박진휘
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 1998년도 추계학술대회 논문집
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    • pp.15-18
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    • 1998
  • Recently, domestic datawarehouse marketplaces take up the most important part of information technology investments with ERP(Enterprise Resource Planning), EC(Electronic Commerce) construction projects in spite of a business slowdown for IMF environment. Therefore, in industrial fields as finances, communications, manufactures, distributions, and so on, datawarehouse was constructed or is under construction, and datawarehouse success stories was showed around some enterprises that has constructed previously datawarehouse. This study is intended to be henceforth an index and direction for an actual proof study by discussing a study of methodology for datawarehouse construction in order to compare and analyze Top-down & Bottom-up approach for datawarehouse that has constructed in actual enterprises.

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마이크로파일로 보강된 모래지반의 지지력 증가효과에 관한 실험적 연구 (An Experimental Study on the Increase of the Bearing Capacity on Sandy Ground due to Micropile Reinforcement)

  • 김정동;임종철;이태형
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.411-416
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    • 2003
  • As rapid industrialization continues in these days, construction in the down town areas increases. Since constructions are performed around old and existing structures, the need to provide reinforcements to protect the existing structures from collapse and damage arises. Furthermore, if the construction is to take place in the down town area, difficult work space and damage caused by noise, vibration and collapse of structure can't be ignored. Among the remedial measures available today, micropile reinforcement is considered the best method to remedy these problems. But up to the present the characteristics of micropiles and ground behaviour has not been proven and no standard design is not yet available. Therefore, most design are performed based on previous experiences. In this study, the difference in the bearing capacity with changing reinforcement angle, space and sphere around foundation was monitored. These results were induced to broaden heighten the limits of micropile application.

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무선 센서 네트워크에서 에너지 효율적인 토폴로지 구성을 위한 Up-Down Tree 라우팅 알고리즘 (An UDT(Up-Down Tree) Routing Algorithm for Energy-Efficient Topology Construction in Wireless Sensor Networks)

  • 노태호;정광수
    • 한국정보과학회논문지:정보통신
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    • 제34권5호
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    • pp.360-369
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    • 2007
  • 무선 센서 네트워크는 제한된 배터리를 갖는 노드로 구성되므로 전체 네트워크의 수명을 극대화하면서 에너지 효율적인 라우팅을 수행할 수 있도록 토폴로지(topology)를 구성하는 것이 중요하다. 이와 관련된 기존 연구들은 무선 센서 네트워크의 특정한 통신 패턴을 고려하지 않고 토폴로지를 구성하여 라우팅을 수행한다. 본 논문에서는 동적으로 전송 범위를 차별화시켜 라우팅을 수행하는 UDT(Up-Down Tree) 라우팅 알고리즘을 제안하였다. UDT는 전송 범위에 기반하여 트리(tree) 토폴로지를 구성하며, 무선 센서 네트워크의 특정한 통신 패턴에 맞게 트리 구성 단계와 데이타 수집 단계에 따라 전송 범위를 조절한다. 따라서 UDT는 전체 네트워크의 수명 극대화, 파티션(partition) 방지, 그리고 에너지 효율성을 향상시킬 수 있다. 실험을 통해 제안한 UDT가 최적의 토폴로지를 구성하여 에너지 효율성 측면에서 좋은 성능을 보임을 확인할 수 있었다.

PSC 연속 거더교의 연속화부 거동에 관한 해석적 연구 (Analysis of the Behaviors of Continuous parts in Continuous PSC Girders Bridges)

  • 구민서;김훈희;정영도
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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    • pp.404-411
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    • 2002
  • The PSC 2-span-continuous-bridge by Up-Down Method on construction process is used for this research. It is measured the strain of lower-steel-plate at continuous section on the active range of negative moment at the stage of introducing compressive stress to bottom-plate and compared with results of structural analysis. On the basis of these results, it is confirmed the introduced compressive stress tか bottom-plate. The object of this research is presenting the degree of continuity at the stage of lifting up process.

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팽창재를 사용하는 바닥 모르타르의 특성에 미치는 시공요인의 영향 (Influences of Construction Conditions on the Properties of Cement Mortars in Floors Using Expansion Agent)

  • 표대수;정성철;송명신;홍상희;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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    • pp.925-928
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    • 2000
  • In this paper, physical properties of cement mortar for floor using expansion agent are discussed varied with mixing time and curing temperature, delivery time and content of added water for preventing fluidity loss. According to experimental results, slump loss shows high with elapse of time And as curing temperature goes up, it also show high when curing temperature goes up and time lag between mixing and casting increases. As curing temperature goes down, drying shrinkage shows to be decreased. But it shows decline tendency with increase of added water content.

건설현장 작업복의 패턴디자인 개선에 따른 동작기능성 평가 (The Evaluation of Movement Functionality on Improved Pattern-Design Working Uniform of Construction Site Worker)

  • 김성숙;김희은
    • 한국의류산업학회지
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    • 제9권2호
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    • pp.237-242
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    • 2007
  • The purpose of this study is to examine the functionality with improved pattern-design working uniform(protocol, P) and current working uniform(control, C). Movement functionality evaluation of improved pattern-design working uniform was carried out through sensory evaluation of working uniform. Movements for the sensory evaluation consisted of four types of up and down and horizontal movements of the shoulders, four types of waist movements and five types of knee movements. The results have been shown as follows: The sensory value of back girth, wrist, side seam area of the "P" with the posture of raising an arm forward up to $90^{\circ}$ and the maximal arm's vertical movement significantly improved compared to the "C". Therefore, it can be concluded that movement functionality was increased with the improved pattern-design working uniform in the respect of arm's up and down movement. Furthermore, for P, Movement functionality improvements were shown in P with arm's horizontal movement, waist bending movement, and knee movement. Current working uniform(C) is jumper-type which wa designed without consideration for movement functionality of the arms and legs. But Pattern-design uniform(P) which was developed in this study. Therefore, the more patterns development, the better movement functionality in working uniform. The improved movement functionality improvements in working uniform will provide not only personal pleasantness but also efficiency of productivity at construction sites. In respect of human body's movement, further study for improved working uniform is required.

VLSI회로의 전력분배 합성과 면적 최적화에 관한 연구 (A study on the Power Distribution Synthesis and Area Optimization of VLSI Circuits)

  • 김현호;이천희
    • 한국컴퓨터정보학회논문지
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    • 제3권4호
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    • pp.63-69
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    • 1998
  • 전력분배 네트워크의 면적 최적화는 VLSI 시스템의 레이아웃 디자인에 중요한 문제이다. 본 논문에서는 전압 하강과 전기 이동 제약을 만족하는 전력분배 네트의 최소 면적을 디자인 하기위해 문제를 해결하는 새로운 방법을 제안한다. 전력 네트 디자인에 대한두가지의 새로운 greedy heuristics을 제안했는데 하나는 bottorm-up 트리 구조와 다른 하나는 top-down 분리 분할 기법을 기본으로 한 것이다.

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Investigation on ground displacements induced by excavation of overlapping twin shield tunnels

  • Qi, Weiqiang;Yang, Zhiyong;Jiang, Yusheng;Yang, Xing;Shao, Xiaokang;An, Hongbin
    • Geomechanics and Engineering
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    • 제28권5호
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    • pp.531-546
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    • 2022
  • Ground displacements caused by the construction of overlapping twin shield tunnels with small turning radius are complex, especially under special geological conditions of construction. To investigate the ground displacements caused due to shield machines in the unique calcareous sand layers in Israel for the first time and determine the main factors affecting the ground displacements, field monitoring, laboratory geological analysis, theoretical calculations, and parameter studies were adopted. By using rod extensometers, inclinometers, total stations, and automatic segment-displacement monitors, subsurface tunneling-induced displacement, surface settlement, and displacement of the down-track tunnel segments caused by the construction of an up-track tunnel were analyzed. The up-track tunnel and the down-track tunnel pass through different stratum, resulting in different construction parameters and ground displacements. The laws of variation of thrust and torque, soil pressure in the chamber, excavated soil quantity, synchronous grouting pressure, and grout volume of the two tunnels from parallel to fully overlapping orientations were compared. The thrust and torque of the shield in the fine sand are larger than those in the Kurkar layer, and the grouting amount in fine sand is unstable. According to fuzzy statistics and Gaussian curve fitting of the shield tunneling speed, the tunneling speed in the Kurkar stratum is twice that in the fine-sand stratum.

보급형 신한옥 개발을 위한 건설 생산성 분석 (Comparative Analysis of Construction Productivity for Modernized Korean Housing (Hanok))

  • 김민;김예솔;이윤섭;정영수
    • 한국건설관리학회논문집
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    • 제14권3호
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    • pp.107-114
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    • 2013
  • 근래에 들어 한옥에 대한 인식의 변화와 더불어 한옥에 살고자 하는 선호도가 증가하는 등 한옥에 대한 관심이 급증을 하고 있는 가운데 정부에서는 한옥에 대한 제도를 개선하고 예산을 반영하는 등, 한옥관련 사업을 다각도로 추진하고 있다. 그러나 상대적으로 높은 공사비는 한옥의 대중화 및 지속적 발전에 장애요인중의 하나가 되고 있다. 이를 개선하고자 정부에서는 '한옥기술개발'의 R&D사업을 추진하고 있으며, 그에 따라 본 논문은 '한옥기술개발'의 일환으로 실제 지어진 전통한옥과 신한옥의 생산성을 토대로 효율적인 공사비 저감의 방향을 제시하고자 한다. 분석방법으로 한옥공사의 15개 대공종 중 주요공종을 선정하였다. 전통한옥과 신한옥 공사 중 주요공종에서의 생산성을 분석하여 재료와 공법의 변화가 생산성에 미치는 영향을 분석하였다. 그 결과, 분석한 주요공종 모두에서 생산성이 향상됨을 확인하였다. 또한 생산성의 향상이 공사비 저감에 어떠한 영향을 끼쳤는지 분석하였다. 주요공종 중 지붕/홈통의 공종은 주로 재료의 변화, 목공사와 마감공사는 공법의 변화, 기초공사와 창호는 재료와 공법 모두의 변화로 인하여 공사비 저감을 이루었다.

FTA기법에 의한 원전기동전원의 이용율 예측에 관한 연구 (A Study on the Availability Prediction of Start-up Power Supply in Nuclear Power Plant by FTAMethod)

  • 최규식
    • 대한전기학회논문지:전력기술부문A
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    • 제48권5호
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    • pp.517-523
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    • 1999
  • The Start-up transformers or on-site stand-by transformers are installed for the start-up and shut-down of generator and emergency status in unclear power plant. The on-site power supply configuration using these transformers must be detemined by considering configuration requirements, site characteristics, reliability and availability severely because it is remarkably important for safety and benefit of plant. The start-up or stand-by power supply configuration has been determined considering only safety requirements and construction cost up to now in Korea. I study various reliability estimating methods for the prediction of availability, and estimate the unavailability for the start-up power supply system of two 1,000㎿ unclear power plants. I also detemine the reliability and unavailability and unavailavility of equipment, system and configuration using FTA method.

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