• Title/Summary/Keyword: 공동현상

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골재비축계획

  • 한국주택협회
    • 주택과사람들
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    • no.3 s.20
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    • pp.33-36
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    • 1992
  • [ ${\circ}$ ] 건설부는 성수기의 골재 부족 현상과 비수기의 골재생산업체의 경영난을 해소하기 위하여 골재비축계획을 마련하였음. -골재수요는 건설경기의 계절성으로 인하여 변동폭이 큰 반면 골재공급은 주문생산성 및 비탄력성으로 매년 성수기에 골재 부족현상이 나타나고 있으며 -골재생산업체는 비수기의 골재수요 감소로 조업의 중단 또는 단축이 불가피하여 유휴장비${\cdot}$인력의 발생으로 경영의 비효율성 초래 -따라서 비수기의 골재를 비축하므로서 ${\cdot}$ 골재수요를 창출하여 골재생산업체의 유휴장비와 인력의 활용이 가능하게 하여 경영의 어려움을 해결하고 ${\cdot}$ 비축골재를 성수기에 방출하여 골재부족현상에서 오는 골재가격의 상승과 부실공사를 방지하고자 함. ${\circ}$ 골재 비축 계획의 주요내용을 보면 -골재 비축자금 : 국민주택기금 100억원(연리 $10{\%}$ -비축자금 대여대상 : 1) 신도시 건설에 참여한 주택건설등록업자 중 현장에 배처플랜트 설치업체 2) 수도권 소재 KS 레미콘 생산업체 3) (주)한국골재산업 -자금대출공고 : ''91. 11. 25${\~}$''91. 11. 30(주택은행) -대상업체 선정 : ''91. 12. 1${\~}$''91. 12. 5(한국주택사업협회, 레미콘 공업협회 및 조합, (주) 한국골재산업이 상호 협의하여 결정) ${\circ}$ 예상 비축량은 매사 1,000천${m^{3}$로 동일조건 일괄공동계약 방식에 의해 12월${\~}$2월에 구매하여 5월${\~}$6월과 10${\~}$11월 성수기에 방출할 예정임.

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Fracture Characteristics in Geologic Media for Groundwater Flow : Review (암반의 지하수유동해석을 위한 지하매질의 열극특성 개념에 대한 고찰)

  • 배대석;송무영
    • The Journal of Engineering Geology
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    • v.5 no.2
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    • pp.201-213
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    • 1995
  • Understanding of the fracture processes in rock mass for hydrogeology necessitates such information as fracture mechanics including genesis, propagation, termination, and the relation of fracture distribution to geologic structures and fracture modelling, etc. A current status of information on fracture for groundwater flow in rock mass, however, is very paucity except on a few special fields throughout the world. The desired and reasonable approach method in the evaluation on the groundwater flow in fractured rock mass must be based on the thorough understanding of fracture processes and a simplified model representing fracture properties which would be met to natural conditions for the interpretation and prediction.

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Conceptual Design of An Underwater Vehicle Powered by Water-breathing Ramjet (해수흡입 램젯추진 수중운동체 개념설계)

  • Um, Jaeryeong;Lim, Hyunae;Jin, Wansung;Choi, Jeong-Yeol
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.4
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    • pp.50-60
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    • 2014
  • Many countries are paying efforts to the research and development of water-breathing ramjet propulsion for submersible vehicle with the super-cavitation which makes traveling at high speed in underwater possible. In this study, a conceptual design of an underwater vehicle with water-breathing ramjet was carried out. Mission profiles and operating conditions are determined by examining the operation environment. Drag is estimated based on the theories of super-cavitation and fluid mechanics. The sizing and performance analysis of the components were performed using thrust required, thrust and specific impulse of designed engine were verified.

Study on the Vortex Shedding Phenomena Near Free Surface (자유수면 근처에서의 보오텍스 방출 현상에 관한 고찰)

  • Seok-Won Hong;Pan-Mook Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.28 no.2
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    • pp.118-131
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    • 1991
  • The effects of free surface on vortex shedding phenomena around a bluff body were studied by both numerical simulation and flow visualization experiments. A vortex method, which approximates the vorticity field as the sum of discrete vortices; was used for the numerical simulation. Flow visualization experiments were performed in the KRISO cavitation tunnel. Hydrogen bubble was used as illumination material. Free surface elevation was also measured during experiments. The hydrodynamic drag and lift were predicted by numerical simulation. The predicted period of vortex shedding was compared with the results of experiments.

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An Analysis of Firm Relocation into or out of Busan Metropolitan Region and De-industrialization (부산지역 전출입 기업의 재입지 특성과 산업공동화에 관한 연구)

  • Kwon, O-Hyeok;Choi, Hong-Bong;Kim, Eun-Young
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.3
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    • pp.412-427
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    • 2008
  • The purpose of this paper is to examine the characteristics of firms relocation into or out of Busan Region. Especially, it analyses the relation between relocated regions, firms' sizes and industrial sectors of the relocated firms systematically. For this, examinations of former studies about firm relocations, forming of analytical framework for systematic investigation were done. In short, this analysis figures out the correlation between the firms' characteristics and relocations.

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Detonation Wave Studies for CVC Engines of TBCC (TBCC를 위한 CVC 엔진의 데토네이션 현상 기초 연구)

  • Choi, J.Y.;Parent, Bernard;Cho, D.R.;Kang, K.;Shin, J.R.;Lee, S.H.;Yi, T.H.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.11a
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    • pp.326-329
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    • 2008
  • DARPA's hypersonic propulsion program VULCAN is aimed for development of Mach 4+ capable engine by combining current production turbofan engine such as F119 with CVC (Constant Volume Combustion) engine. Final goal is a TBCC(Turbo-based Combined Cycle) engine by combining with dual mode ramjet/scramjet engine. CVC is a common designation of new concept of high efficiency engines, such as Pulse Detonation Engine (PDE) or Continuous Detonation Engine (CDE), which use the detonation as a combustion mechanism. Present paper introduces the internationally collaborative research activities carried out in Aerospace Combustion and Propulsion Laboratory of the department of Aerospace Engineering of the Pusan national University.

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The Research of an Analysis of Community Consciousness in Local Area for Developing Reading Contents: Case of G City (독서문화콘텐츠 개발을 위한 지역공동체의식 분석에 관한 연구 - G시를 대상으로 -)

  • Ahn, Inja;Hoang, Gum-Sook;Park, Mi-Young
    • Journal of the Korean Society for Library and Information Science
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    • v.48 no.2
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    • pp.259-285
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    • 2014
  • Public policies in regard to developing reading culture programs and the contents, and in running public libraries have been used to overcome existing social issues such as regional self-centeredness and cultural lagging. It means that public libraries are playing an important role to encourage communications within local communities. The purpose of this research is therefore to analyze the concept of local community, and develop reading culture and contents to reinforce the concept. This research also targeted to analyze the required contents in reading culture. Through the case study of "G" city, the research analyzed their citizenship and sense of local community and the requests. As a result, the requited subjects were for economics, unemployment, poverty, aging, and housing order. For the subjects of environment were environment pollution and energy order. For the subjects of human rights, disabilities, and multi-cultural were requested. For the subject of education, school violence, tutoring, and truly teaching were requested. Based on the requirements, 221 items of reading lists, DVD clips, and abstracts are developed as well as 4 programs of reading culture.

Governance of a Growing Creative Industry Cluster: A Case Study on Brooklyn in the US (창조산업 클러스터의 형성과 발전의 거버넌스에 관한 연구: 미국 뉴욕 브루클린의 문화예술 산업클러스터를 사례로)

  • Shin, Dong-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.1
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    • pp.71-85
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    • 2011
  • Many of the old industrial cities in advanced economies have experienced deindustrialization since the 1960s. While some of them have been transforming their economic structures with new economies, such as arts and cultural industries, others have been seriously suffering from economic and social problems. Brooklyn Borough of New York City is one of the best examples which have gone trough rapid de-industrialization; but have been reasonably successful in recovering its economy with arts and cultural industries. This paper introduces the process of developing creative industry clusters, articulates major actors, and find out the governance of the clusters, using three Brooklyn's arts clusters, such as DUMBO, BAM and Williamsburg. Based on the case studies, the paper draws theoretical and policy implications applicable to the Korean circumstance.

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Estimation of Ground Vibrations Around a Pillar Due to Blast Loading and the Impact of Flyrocks (발파하중 및 비석의 충격에 의한 광주의 지반진동의 예측 연구)

  • Lee, Sang-Gon;Kang, Choo-Won;Chang, Ho-Min;Ryu, Pog-Hyun;Kim, Jang-Won;Song, Ha-Rim;Kim, Seung-Eun
    • Explosives and Blasting
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    • v.28 no.1
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    • pp.1-10
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    • 2010
  • In blasting for lighting, fatigue behaviors of pillars such as destruction and deformation may occur due to blasting vibration and flyrock, which may cause collapses of cavities. This study aims to identify dynamic behavior of pillars to maintain efficient safety of cavities in large drafts. when they collide with flyrocks under blasting for the excavation. For the purpose, we compared ground vibration around pillar when flyrock collided with the pillar and that when explosive blast happened for the excavation. we conducted fragmentation analysis of the flyrock and compared impact vibration obtained from empirical equation with ground vibration obtained from regression analysis of real vibration data. also we compared those with results analyzed from numerical analysis.

Study of Brittle Failure (취성파괴에 관한 고찰)

  • Cheon, Dae-Sung;Synn, Joong-Ho;Jeon, Seo-Kwon;Park, Chan
    • Tunnel and Underground Space
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    • v.16 no.6 s.65
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    • pp.437-450
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    • 2006
  • Failure around an underground opening is a function of in-situ stress magnitudes, intact rock strength and the distribution of fractures in the rock mass. At high in-situ stress, the failure process is affected and eventually dominated by stress-induced fractures preferentially growing parallel to the excavation boundary. This fracturing is often observed in brittle type of failure such as slabbing or spatting. Recent studies dies on the stress-induced damage of rock revealed its importance especially in a highly stressed regime. As the constructions of underground structures at deep depths increased, the cases of the brittle failure also increased and furthermore spalling was occurred in Korea at low depths. To improve the stability of the underground structures at highly stressed regime, the characteristics of brittle failure should be examined, but they have not yet been properly investigated. Therefore in this report the characteristics of brittle failure such as types, failure mechanism and modeling methods etc. were considered in all aspects, based on the previous researches.