• 제목/요약/키워드: Various problems on land

검색결과 226건 처리시간 0.027초

A study on the heat release rate pattern variation according to the change of operating conditions in pre-combution chamber type diesel engine (예연소실식 디젤기관의 운전조건변화에 따른 열발생률 형태변동에 관한 고찰)

  • 이진우;최재성;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • 제11권3호
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    • pp.31-44
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    • 1987
  • Nowadays, the problems of energy and environmental pollution become serious day by day and the diesel engine, which has been proved to be superior to gasoline engine with respect to fuel consumption and ecological problems of exhaust gas, has been adopted widely for various purposes from the marine diesel engine and the dynamo engine to all kinds of engine on land. Therefore, extensive parametric studies on combustion of diesel engine should be done for its desing and improvement. To predict the behavior of diesel engien according to variable operating conditions by means of cycle simulation, the reasonable pattern of heat release rate has to be asumed. But it is necessary to know the actual variation of heat release rate in order to assume the reasonable pattern of heat release rate according to the actual operating conditions. In this paper, on a high speed small bore diesel engine with pre-combustion chamber, experimental investigations were carried out to determine the relationship between the heat release pattern and parameters such as engine load and speed. And also, the theoretical investigations about the performance variations of the above diesel engine according to the predicted pattern of heat release rate variation were performed. From the above observations, it may be said that the Fanboro indicator, which was used to get the cylinder pressure, can be used to estimate a reasonable pattern of heat release rate and it is confirmed that the pattern of heat release rate for the pre-combustion type engine is different from that of the direct injection type engine.

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Research on the Residential Environment of New Town & Surrounding Area (대규모 신도시 및 주변지역 거주환경 비교분석 연구)

  • Cho, Young-Tae;Seong, Jang-Hwan
    • Land and Housing Review
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    • 제2권1호
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    • pp.1-8
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    • 2011
  • During the 1990's, five new towns were constructed around Seoul such as Bun-Dang and Il-San. These new towns are very popular since they were created based on systemic urban planning and they provide various residential amenities. Many people consider them livable cities. Taking such advantages, other small-scale new public and private developments continued around those new towns and consequently created 'agglomerated region with new development'. The most representative area is Bun-Dang and north-western Yong-In area which are formed along the Seoul-Busan expressway. This area is a mega-community having more than one million residents in 2005.Judging from recent development trends in the Seoul metropolitan area, it is expected that the formation of other 'agglomerated region with new development' would be continued for the time being. This study is aimed to analyze the residential environment of Bun-Dang and north-western Yong-In and find implications to the management of 'agglomerated region with new development'. The relevant existing studies have their limits, only focusing on analyzing current conditions and pointing out current problems. This study could be differentiated from the existing analyses in that it conducted comprehensive analyses on various factors that constitute urban residential environment. The conclusion of this study was derived from diverse analyses of current development condition, residential sites, regional transportation, awareness of residents, and oversee cases.

Preliminary Investigation for Apply of e-Government Framework at the Construction CALS System (건설CALS시스템에 전자정부 표준프레임워크 적용을 위한 사전 고찰)

  • Yang, Sung-Hoon;Kim, Nam-Gon
    • The Journal of the Korea Contents Association
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    • 제13권11호
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    • pp.433-440
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    • 2013
  • The Ministry of Land, Infrastructure and Transport was developed the Construction CALS system for improvement of the construction economy. Construction CALS system is consist by Construction Portal System, Construction Management System, Construction Authorization and Permission System, Compensation Management System, Facility Maintenance Management System and has utilized at construction site of more than 900. Ministry of Land, Infrastructure and Transport and related researcher was proposed method of various function improvements for usability of the system. However, the proposed method was expanded the problems like increase of system management cost and development cost with decrease of data process rate. The problem was increases because has added of only service function without modify of software structure to the system on each different platform base. One of the methods for solving problems is to apply the e-Government framework and then integrated the different platform. The purpose of this paper is analyse of the applicability and efficiency of e-Government framework to the construction CALS system. For that was analyzed the e-Government standard framework and the developments case. And then was verified about the adaption possibility and efficiency by use the Function Point tool.

A Case of the Alternative Method to Improve the Ambient Vibration Blasting Method Applied NATM Tunnel Construction in Urban Areas (도심지 NATM 터널 굴착시 적용된 미진동발파 공법 개선사례)

  • Lee, Jong-Yoon;Hwang, Yeon-Soo;Choi, Hack-Yong;Bae, Hyo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.535-542
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    • 2010
  • Various difficulties have been increased in the construction of public structure; like the road in the overcrowding urban area, because of civil complaint, cost and period of construction. In oder to overcome these social problems, the tunnel has been planned the road design. Despite the resolution, there are many technical problems when constructed near facilities. The design of new tunnel below the existing service reservoir is applied to the ambient vibration blasting using Plasma. The result of test blasting was exceeded the standard ("2kine"). So it was considered a countermeasure for the vibration reduction applied to change the controlled blasting method, reduce the charge, add the pre middle horizontal hole in the cut blasting site, and so on. The result was satisfied the standard. Accordingly, if the quality of blasting process can be managed well, the application of this alternative method is highly effective one. Also, based on cost analysis between two methods, the alternative method is very competitive.

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Hydrodynamic Interaction Analysis of Floating Multi-body System

  • Kim, Young-Bok;Kim, Moo-Hyun;Kim, Yong-Yook;Kim, Young-Hun
    • International Journal of Ocean System Engineering
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    • 제1권4호
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    • pp.198-204
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    • 2011
  • Recently, several problems have occurred in the space, infra-structure, and facility of the contiguity of existing harbors due to the trend of enlarged container vessels. In this regard, the Mobile Harbor has been proposed conceptually in this study as an effective solution for these problems. The concept is that of a transfer loader that transfers containers from a large container ship to the harbor on land, and is a catamaran type floating barge. The catamaran-type vessel is well known for its advantage in maneuverability, resistance, and effectiveness for working on board. For the safe and effective operation of the two floating bodies (a container ship and the mobile harbor in the near sea detached from the quay), robot arms, novel crane systems, and pneumatic fenders are specially devised with an additional mooring facility or DP (dynamic positioning) system. In this study, this concept is to be verified through comparison and simulation studies under various environmental conditions. It is shown that the proposed concept is in general feasible but there are several areas for further investigation and improvement.

A Case Study on the Construction of 3D Geo-spatial Information for Digital Twin Implementation (디지털 트윈 구현을 위한 3차원 공간정보 구축사례 연구)

  • KIM, Seung-Yub;LEE, Ho-Hyun;CHOI, Eun-Soo;GO, Je-Ung
    • Journal of the Korean Association of Geographic Information Studies
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    • 제23권3호
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    • pp.146-160
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    • 2020
  • In the 4th industrial revolution, research on solving urban problems using ICT technology is emerging. Representatively, research is being conducted mainly focusing on smart cities. 3D geo-spatial. Various case studies on smart cities are being conducted to solve urban problems, and in order to effectively implement smart cities, it is implemented on the basis of a digital twin interconnecting physical and virtual environments. To implement a digital twin, the concept of space is essential, and spatial information that composes the real world is also essential. Therefore, in order to implement the digital twin, this study conducted a study on the construction and modeling of 3D geo-spatial information based on the national spatial information establishment regulations and the international standard CityGML for buildings, water facilities, and transportation facilities in Jeonju. In Jeonju, the research area, the LOD was defined, and the possibility of digital twin based on geo-spatial information was determined through data collection, analysis, and construction for each detail. In this study, it is meaningful that a plan to construct geo-spatial information for the implementation of a digital twin is presented, and the result of the construction is modeled as an urban standard model. The results of study are expected to be used as reference for detailed construction plans and standard establishment by governments and local governments promoting smart city and digital twin construction in the future.

Establishing the Managerial Boundary of the Baekdu-daegan(II) - In the Case of Semi-mountainous District - (백두대간 관리범위 설정에 관한 연구(II) - 준산악형 구간을 대상으로 -)

  • Kwon, Taeho;Choi, Song-Hyun;Yoo, Ki-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • 제7권1호
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    • pp.62-74
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    • 2004
  • Baekdu-daegan is the greatest mountain chain as well as the major ecological axis of the Korean Peninsula. In recent year, however, this area is faced with the various kinds of developmental urge. To cope adequately with these problems, this study was executed to prepare synthetic and systematic management with conservation-oriented strategy for Baekdu-daegan and to suggest spatially definite zoning for the managerial area. This study is to take into consideration the traditional concepts of stream and watershed as well as the actual disturbance on Baekdu-daegan area. The study area is selected with semi-mountainous type, from Namdeokyusan to Sosagogae. To propose the process for reasonably establishing the managerial boundary adjacent to the Ridges, the analysis was carried out that ArcGIS was mainly used for its analysis with digital maps, Landsat TM image and ArcGIS Hydro Model. Landsat TM image was classified by 5 land use types such as cultivated land, urban area, barren area, water body and forest. Based on these analyses results, the managerial boundaries as alternatives from the Ridges were produced by watershed expansion process, and used for tracing the changes of areal ratio of various land use types to the relevant watersheds to search out the adequate managerial boundary. The results show that watershed expansion process could be effective tool for establishing the managerial boundary, and eighth expanded watershed toward Muju-Gun(west) and fifth expanded watershed toward Geochang-Gun(east) might be included for the adequate managerial boundary of the case site.

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Nutrient Recycling : The European Experience - Review -

  • Hall, J.E.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권4호
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    • pp.667-674
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    • 1999
  • Intensive livestock production has increased dramatically in Europe since the 1960s, particularly. in Northern and Central European countries, resulting in large increases in the nutrient pollution of surface and ground waters and in atmospheric emissions of ammonia. This has arisen due to inadequate management of the large amounts manure produced, particularly where there has been insufficient land area used for efficient nutrient reuse in crop production. Nutrient pollution from intensive livestock production has progressively degraded the quality of water resources in many parts of Europe, with eutrophication of many inland and coastal waters, as well as soil acidification and ecosystem degradation. These problems have been known for many years, and although there are various international agreements on transboundary pollution, it is largely left to individual countries to set and enforce standards. Consequently, a number of different approaches are employed, although the common feature of these is to encourage farmers to use the nutrients in animal manures efficiently according to crop requirements, which also reduces the potential for accumulation in soil and subsequent loss to the environment. This paper reviews nutrient production and use in Europe and some of the strategies employed to avoid and reduce nutrient pollution.

Behavior and Lateral Force of H-piles under lateral Soil Movement in Sand (측방변형을 일으키는 모래지반속의 H형 말뚝에 작용하는 수평력)

  • 김영인
    • Journal of Ocean Engineering and Technology
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    • 제16권6호
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    • pp.44-48
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    • 2002
  • In lateral ground flow, slope stability, and land slide problems, H-piles have often been used, on a horizontally deforming ground, to prevent the failure of mass of soil in a downward and outward movement of a slope. Here, theoretical equations are derived to estimate the lateral force, assuming that the Mohr-Coulomb's plastic states occur in the ground, just around H-piles. In this study, some model experiments were performed to check the lateral forces determined from theoretical equations, using several pile widths, heights and various interval ratios between H-piles for sand specimens. The solution of the theoretical equation, derived from previous studies, showed reasonable characteristics for constants of soil, as well as for the interval, widths, and heights of H-Pile.

Management Strategies of Livestock Waste Minimization and Resource Conservation

  • Kim, Kyung-Sook;Won, Hyo-Joung;Chung, Jae-Chun;Choi, Deuk-Soo
    • Journal of the Korea Organic Resources Recycling Association
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    • 제8권1호
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    • pp.83-89
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    • 2000
  • There is no simple method to solve livestock waste problems satisfactorily. For a successful solution, various methods should be well organized orderly depending upon the situation. Even in the livestock waste management, integrated waste management principle should be applied. Minimization of livestock waste generation is the first priority. It is also important to distribute fairly livestock farms throughout the nation. Efficient management of permit system is equally important. Permit should be given only when the farmer have enough grass-land on which the farmer can apply more than two thirds of livestock waste generated or when the farm have an anaerobic digestor in which store livestock waste generated for at least 3 months. In principle, livestock waste should be treated in the farm and it is desirable to operate composting facilities in the farm site too.

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