• Title/Summary/Keyword: Covering Problems

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A case study on optimal location modeling of battery swapping & charging facility for the electric bus system (전기버스를 위한 배터리 자동 교환-충전인프라 배치 최적화 모형개발 및 적용 사례 분석)

  • Kim, Seung-Ji;Kim, Wonkyu;Kim, Byung Jong;Im, Hyun Seop
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.1
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    • pp.121-135
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    • 2013
  • This paper propose an efficient algorithm for selecting electric bus charging facility location. In nature, the optimal charging facility location problem is similar to Set Covering Problem. Set Covering Problem is the problem of covering all the rows of an $m{\times}n$ matrix of ones and zeros by a subset of columns with a minimal cost. It has many practical applications of modeling of real world problems. The Set Covering Problem has been proven to be NP-Complete. In order to overcome the computational complexity involved in seeking optimal solutions, this paper present an enhanced greedy algorithm and simulated annealing algorithm. In this paper, we apply the developed algorithm to Seoul's public bus system.

Optimal Location of Expressway Patrol Vehicle Stations Using Maximum Covering and Weighted p-Center Problems (Maximum Covering 문제와 Weighted p-Center 문제를 이용한고속도로 순찰대 최적 입지 결정)

  • Kim, Myeonghyeon;Kim, Hyo-Seung;Kim, Dong-Kyu;Lee, Chungwon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.1
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    • pp.43-50
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    • 2013
  • This paper aims to determine the optimal location of expressway patrol vehicle stations that minimizes additional troubles caused by the delay of crash treatments. To do this, we formulate a maximum covering problem and a p-center problem weighted by crash frequency, using the shortest distance as the criteria for allocating service district, and we employ the Lagrangian relaxation algorithm to solve the former and Daskin's heuristic algorithm to solve the latter, respectively. Based on crash data of Korean expressways, the results from the proposed models are compared with the current location of patrol vehicle stations by using several indices as the level of service for crash treatment, such as maximum crash-weighted distance, average crash-weighted distance, and average access distance. The results show that the proposed models improve average access distance and time by about 10km and 10min, respectively. When allocation for service district is changed only with the fixed current location, the level of service can be also improved. The models and results proposed in this paper can contribute to improving the level of service for crash treatment on expressways. They can also provide the theoretical basis on the location decision for other various emergency facilities, and the allocation decision for floating service districts according to time-period crash data.

Analysis of Ecological Landscape Planning and Policy in Germany (독일의 생태학적 조경계획 정책분석 -독일 자연환경보존법을 중심 으로-)

  • ;L, Finke
    • Journal of the Korean Institute of Landscape Architecture
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    • v.22 no.2
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    • pp.105-122
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    • 1994
  • The landscape plannings were composed of the fundamental provisions which are important factors for the city and local plannings in Germany. The State Government run institute like LOLF in NRW have been established to solve the serious ecological problems. The institute have completed the basic system covering various ecological problems, such as environmental affection analysis and ecological risk, to contribute the application of the various land-using plants. The ecological landscape plannings are regarded as major fundamental plans of environmental preservation for the plannings development. The problems about the local landscape plannings needed to be preserved ecologically are introduced into the Federal Nature Preservation Law and State Congress Law in order to carry out the environmental protection policy effectively. The local landscape plannings are divided into two-step models by the special classification system for the planning. One is build-up of an independent design separated from city plans functionally, and the other is a systematic regulation for cooperation between the local plans and ecological conservation functions. The local plannings including lands to be preserved as the Nature Preservatin Zone is classified a rest area total sectioned plains.

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The Experimental Study of Inorganic Performanent내s of Fire Resistance Evaluation (무기질계 영구거푸집의 내화성능에 관한 실험적 연구)

  • 김영진;백민수;정근호;김우재;정상진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.495-500
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    • 2002
  • The purpose of this study is to develop and to apply this permanent cement mortar form as one of those system forms to improve existing form's problems. (1) In the fire proof test with combined specimen, the fire proof covering including form section thickness is satisfied with the fire proof criterion. It is considered that form section thickness has no problem (2) The suitable method of normal pressure steam curing for the form's mass production is 4 hours in 65℃ considering production cost, the silica fume admixture is economic.

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A Study on Removal of Harmful, Heavy Metals in Fly Ash from Municipal Incinerator

  • Nakahiro, Yoshitaka
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.489-493
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    • 2001
  • Big cities in Japan have serious problems due to the shortage of new reclaimed land for municipal wastes. If harmful heavy metals such as cadmium, lead, copper and etc. are contained in the municipal waste combustion residues, they are not able to fill up according to the environmental law in Japan. In this study, the removal of heavy metals in the fly ash (EP ash) was dealt with chloridizing vaporization method. EP ash as a non-hazardous materials is utilized as covering materials, road bed, and building materials.

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DATABASE OF SAR IMAGES OF MONGOLIA AND ITS ROLE FOR UPDATE OF DIFFERENT LAYERS IN A GIS

  • Amarsaikhan, D.;Ganzorig, M.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1090-1092
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    • 2003
  • The aim of this study is to describe the problems and solutions for creating a synthetic aperture radar (SAR) mosaic covering the total territory of Mongolia and highlight the role of the available SAR database for updating different thematic layers stored in a geographical information system (GIS).

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A Study on Contents Development of Water Education for Sustainable Development (지속가능발전을 위한 물 교육 내용체계의 개발)

  • Sung, Jung-Hee;Lee, Jae-Hyuk
    • Hwankyungkyoyuk
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    • v.24 no.2
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    • pp.86-98
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    • 2011
  • Water problems recently, not only influence environmental issues such as water quality and water management but also influence socioeconomic issues such as poverty, gender, and regional conflicts. Therefore there is increasing attention on water education as part of the environmental education. Yet water education in formal education is only treated with particular subjects like science and social studies with limited contents which fails to cover the social, economic problems related to water thoroughly. Also, though there is an active water education on the field of informal education. its contents are also very limited. Water education requires the implementation of a comprehensive and holistic approach that can holistically consider economic and social problems as well as environmental problems. Therefore in this research, 'water education for sustainable development' is set up as a direction of contents development which include interdisciplinary and holistic aspects. Contents development of water education for sustainable development is an reflection of the experts and teacher's opinions and contain of: main category dividing into three pillars of sustainable development such as environment, economy, and society, and subcategory covering environmental science's objective including knowledge, skill, attitude, and action as well as local, national, regional, and global issues.

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A Study on Problem Development of Management subject for BPBL in a Mongolian University. (몽골 대학에서 BPBL을 위한 관리 교과목 문제 개발 연구)

  • Bayarmaa, Natsagdorj;Lee, Keunsoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.683-688
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    • 2018
  • In the 21stcentury, teachers must welcome new technology to ensure the best learning in virtual classrooms, aside from the physical classroom. Google Classroom provides a vital chance to promote blended learning and professional development. The purpose of this study is to specify the procedures in problem design when employing blended problem-based learning (BPBL) and to design problems for learning the contents of the subject. The design of problems is crucial for effective BPBL. The underlying theory of BPBL is that learning is most effectively initiated and facilitated by posing and solving real-life problems that interest the learner, because working on such problems makes learning meaningful and motivates students. Ineffective problem-based learning (PBL) could affect students when acquiring sufficient domain knowledge, activating appropriate prior knowledge, and properly directing their own learning. The procedures for designing good problems are composed of the selection of educational content, figuring out the learner's characteristics, finding problems, setting up roles and situations, and writing down problems. Using these procedures, we designed five integration problems covering the contents of management subjects. Planned management subjects based on BPBL in a Mongolian university focuses on the process of designing problems.

A Study on Improvements of Landscape Impact Assessment - EIA and PER in Priority - (경관영향평가제도의 개선에 관한 연구 - 사전환경성검토와 환경영향평가를 중심으로 -)

  • Choi, Hyung-Seok
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.4
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    • pp.68-80
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    • 2005
  • This study intends to analysis problems and propose of EIA(Environmental Impact Assessment) and PER(Pre-Environmental Review) especially on division of landscape impacts. The problems of EIA and PER are first, on analysis of existing conditions side, insufficiency of the list of landscape elements and their descriptions and presentations, and the number of viewpoints and each validity second, on estimation of landscape impacts, the methods and techniques of estimation and simulation, and the process of impact estimation, third, on suggestion of reduction plans, reduction devices covering impacts, the lack of influence reduction forecasting devices, the deficiency of execution power of reduction plans, finally, the systematic connection of impact estimation with existing conditions analysis and reduction plans. Therefore, on each step from existing condition analysis to reduction plan suggestion, the solutions to each problem are proposed.

디스크형 진동자를 이용하는 새로운 형태의 밸브리스 마이크로 압전 펌프

  • O, Jin-Heon;Im, Jong-Nam;Jeong, Ui-Hwan;Im, Gi-Jo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.91-91
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    • 2009
  • Piezoelectric micro-pump should contain the physical running parts like check valves for acquiring the unilateral motion of fluid from the alternating motion of actuators. But the check valves raise many problems such as abrasion or exhaustive destruction by the recursive mechanical displacement To solve these problems, we propose a novle type piezoelectric valveless micro-pump using peristaltic motion due to the traveling wave excitation. Proposed pump model is consisted of two piezoelectric ceramic plates, elastic metal body, caps for covering flow path, rubber rings for sealing tightly and disk springs for the pressurization of pump body.

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