• 제목/요약/키워드: Flexible Criteria

검색결과 155건 처리시간 0.023초

주행속도 분포 특성을 이용한 설계기준 적용 방안 (A Geometric Design Method Based on the Running Speed Distribution)

  • 정준화;박창호
    • 대한교통학회지
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    • 제23권5호
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    • pp.113-120
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    • 2005
  • 도로 선형 설계의 제1의 목표는 통행의 안전과 원활한 운행 여건을 구조적으로 확보하는 데에 있다. 현재 우리나라 도로 설계법은 외국의 설계기준과 방법론을 바탕으로 한 것이나, 도로를 이용하는 사람이나 차량의 특성이 설계체계에 반영되어 있지 않아, 설계자의 기대와 이용자의 이용 행태간의 간격이 존재하며, 그 결과는 안전하고 편리한 도로를 제공하는 데에 장애가 된다. 도로 기하구조 설계의 적정성을 높이고 안전성을 높이기 위해서는 차량 주행 특성에 기반한 도로 선형 설계기준과 그 적용 체계를 갖출 필요가 있다. 본 연구에서는 실제 도로 이용자의 특성이 반영된 도로 설계 체계를 갖추는 작업의 일환으로 일반국도 4차로도로의 단일 곡선부 구간에 대한 주행 차량의 속도 분포 특성을 바탕으로 일반국도의 선형의 설계기준을 적용하는 방안을 제시하였다.

제 7차 수학과 교육과정 운영에 관한 실태 분석 연구 - 초등 단위학교 및 교사 수준을 중심으로 - (A Study on Implementation of the Seventh Mathematics Curriculum at the Elementary School Level)

  • 최승현;황혜정
    • 대한수학교육학회지:학교수학
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    • 제6권2호
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    • pp.213-233
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    • 2004
  • This study looked into the procedures of and the status on the implementation of the new 7th national curriculum at the elementary school level, especially focused on the subjects of schools and the teachers for the actual curriculum implementation. More specifically the study examined, 1) the degree to which the particular innovation(i.e., student-centered, flexible and autonomous school-based curriculum, etc.) is be-ing implemented as planned; and 2) how it is being implemented. It conducted a situation-oriented analysis in cooperation with three local boards of education. Classroom observations, teacher interviews, questionnaires for teachers and supervisors were utilized and the three major criteria of interpreting the result were the three core concepts of the 7th national curriculum, that is, the degree of "(1)reorganization, (2)student-centeredness, and (3)diversification/specialization" of the curriculum. Detailed documentation on the processes of the local bureaus of education and on the classroom practices are made in order to provide schools and policy makers with relevant and practical suggestions for further improvement of curriculum implementation.

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전력계통의 사고전류 저감 설비별 특성 비교 (Comparison of Fault Current Limiting Characteristics According to Facility in Power System)

  • 박형민;최효상;조용선;임성훈;황종선
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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    • pp.127-129
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    • 2005
  • We investigated the fault current limiting characteristics according to the various facilities in power system. Power systems are becoming larger and larger for meeting electric power demand. Therefore, the over-currents resulting from contingencies such as short circuits are increasing higher, which causes the ratings of circuit breakers(CBs) to increase. Upgrading or replacement of CBs is not difficult from the technical and economical point of view. Bus split is being adopted into a part of 154 kV power systems, but it has adverse effects such as overload to neighboring power systems, increased voltage fluctuation, and decreased power system stability. For 345 kV power systems, the bus split measure is not feasible and dc reactors are being suggested. The superconducting fault current limiter is a protection gear of new concept that limits fault current automatically in a few milliseconds. It can also provide the effect of CB capacity increase, relaxation of power machine criteria, enhancement in power system reliability, and flexible power system operation.

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압력잠김 및 열고착 현상 발생가능 밸브의 선정 (Selection of Valves Susceptible to Pressure Locking and Thermal Binding)

  • 이성노;안진근;김석범
    • 한국유체기계학회 논문집
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    • 제10권5호
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    • pp.20-26
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    • 2007
  • Some gate valves are susceptible to pressure locking and thermal binding which prevent the safety function. The safety related gate valves susceptible to pressure locking and thermal binding shall be identified and taken preventive actions to ensure the safety function. The identification of the gate valves susceptible to pressure locking and thermal binding needs the evaluation of system design, valve and piping arrangement, test requirements, and operating conditions. Application of preventive methods should consider the system safety function, applicability, effectiveness, interface with system design, and cost. The selection procedure of valves susceptible to pressure locking and thermal binding can be effectively used in industry including nuclear power plants. In order to prevent the pressure locking, the hole can be drilled through the one disc of upstream side or down stream and the external equalizing line can be installed from bonnet to downstream or upstream. The double disc parallel seat valve type can be used instead of flexible wedge gate valve to prevent the thermal binding. The identification of gate valves susceptible to pressure locking and thermal binding, and preventive actions will meet the regulatory requirements and enhance the availability and safety of plants.

학교시설개선을 위한 평가지표개발에 관한 연구 (A Study on Developing the Standardized Index of Evaluation for Upgrading the School Facilities)

  • 송병준;김영석;주범
    • 한국실내디자인학회논문집
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    • 제21권6호
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    • pp.260-270
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    • 2012
  • The demographic and environmental changes such as the decrease of the population growth rate and the increase of the population of the senior citizens, which become issues of the modern society, are bringing numerous changes of many aspects like national economy, community, and culture. These social phenomena give impacts on the school facilities as well. Thus owing to the decrease of the number of the students, the number of the newly constructed schools has been decreased drastically, and moreover the merger of the schools cause many schools to be default. Meanwhile, the school facilities have been expanded into the functions of the local community centers, and the various educational activities demand the diversity and flexibility of the spaces. These factors add more burdens to the current schools. Therefore the school facilities are needed to adopt a flexible and relevant change necessary for using the spaces in accordance with the changed needs of the times, and are needed to reinvented continuously not to limit the educational and social activities because of the degradation of the school facilities. Yet because there are no proper criteria for doing the task, problems related to the relevance of the task and the unnecessary investment are raised. So through this study I tried to demonstrate the standardized index in terms of the sequential priority of upgrading the facilities among the schools.

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Effects of taper and set-back on wind force and wind-induced response of tall buildings

  • Kim, Yongchul;Kanda, Jun
    • Wind and Structures
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    • 제13권6호
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    • pp.499-517
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    • 2010
  • Advances in structural materials and construction methods have resulted in flexible and light tall buildings, making an assessment of structural safety during strong wind and serviceability/habitability during comparable medium/weak wind important design criteria. So far, lots of studies on suppressing the wind-induced responses have been carried out for tall buildings with aerodynamic modification. Most of the studies on aerodynamic modification have forced on the corner modification, while the studies on taper and set-back are limited. Changes of sectional shape through taper and set-back can modify the flow pattern around the models, encouraging more 3-dimensionalities, which results in reducing the wind-induced excitations. This paper discusses the characteristics of overturning moments and wind-induced responses of the tall buildings with height variations. The reduction of mean along-wind and fluctuating across-wind overturning moments are apparent in the suburban area than in urban area. A series of the response analyses, the rms displacement responses of the tall buildings with height variations are reduced greatly, while the rms acceleration responses are not necessarily reduced, showing dependences on wind direction.

PCIA 클라우드 서비스 모델링 및 자원 구성에 따른 성능 영향도 분석 (PCIA Cloud Service Modeling and Performance Analysis of Physical & Logical Resource Provisioning)

  • 윤빈풍;곽종욱
    • 한국컴퓨터정보학회논문지
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    • 제19권2호
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    • pp.1-10
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    • 2014
  • 클라우드 컴퓨팅은 융통성 있는 연산능력과 대량의 데이터를 분석하는 효과적인 환경을 제공한다. 본 논문에서는 공용 클라우드를 위한 새로운 타입의 자원 배치 구조를 정의하고 이를 PCIA라고 명명한다. 아울러, PCIA 구조에서 서비스 모델에 대해 소개하며, 이를 위한 클라우드 명명 기법도 제시한다. 제안된 클라우드 시스템은 어플리케이션의 다양한 특징에 따라 사용자의 가상 자원 요구에 기반하는 적절한 물리적 자원을 선택하게 된다. 이를 통해 자원 제공의 변화에 따른 성능 변화의 연관성 및 클라우드 시스템의 효과적 구축을 위한 시스템 구성 요소의 영향도를 분석하며, 클라우드 서비스 제공자와 사용자 양쪽 모두에게 중요한 리소스 프로비져닝의 주요 기준을 제시한다.

A Study on Transmission System Expansion Planning on the Side of Highest Satisfaction Level of Decision Maker

  • Tran TrungTinh;Kang Sung-Rok;Choi Jae-Seok;Billinton Roy;El-keib A. A.
    • KIEE International Transactions on Power Engineering
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    • 제5A권1호
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    • pp.46-55
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    • 2005
  • This paper proposes a new method for choice of the best transmission system expansion plan on the side of highest satisfaction level of decision maker using fuzzy integer programming. The proposed method considers the permissibility and ambiguity of the investment budget (economics) for constructing the new transmission lines and the delivery marginal rate (reliability criteria) of the system by modeling the transmission expansion problem as a fuzzy integer programming one. It solves the optimal strategy (reasonable as well as flexible) using a fuzzy set theory-based on branch and bound method that utilizes a network flow approach and the maximum flow-minimum cut set theorem. Under no or only a very small database for the evaluation of reliability indices, the proposed technique provides the decision maker with a valuable and practical tool to solve the transmission expansion problem considering problem uncertainties. Test results on the 63-bus test system show that the proposed method is practical and efficiently applicable to transmission expansion planning.

Supply Chain Trust Evaluation Model Based on Improved Chain Iteration Method

  • Jiao, Hongqiang;Ding, Wanning;Wang, Xinxin
    • Journal of Information Processing Systems
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    • 제17권1호
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    • pp.136-150
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    • 2021
  • The modern market is highly competitive. It has progressed from traditional competition between enterprises to competition between supply chains. To ensure that enterprise can form the best strategy consistently, it is necessary to evaluate the trust of other enterprises in the supply chain. First, this paper analyzes the background and significance of supply chain trust research, analyzes and expounds on the qualitative and quantitative methods of supply chain trust evaluation, and summarizes the research in this field. Analytic hierarchy process (AHP) is the most frequently used method in the literature to evaluate and rank criteria through data analysis. However, the input data for AHP analysis is based on human judgment, and hence there is every possibility that the data may be vague to some extent. Therefore, in view of the above problems, this study improves the global trust method based on chain iteration. The improved global trust evaluation method based on chain iteration is more flexible and practical, hence, it can more accurately evaluate supply chain trust. Finally, combined with an actual case of Zhaoxian Chengji Food Co. Ltd., the paper qualitatively analyzes the current situation of supply chain trust management and effectively strengthens the supervision of enterprises to cooperative enterprises. Thus, the company can identify problems on time and strategic adjustments can be implemented accordingly. The effectiveness of the evaluation method proposed in this paper is demonstrated through a quantitative evaluation of its trust in downstream enterprise A. Results suggest that the subjective preferences of and historical transactions together affect the final evaluation of trust.