• Title/Summary/Keyword: Local Force

Search Result 755, Processing Time 0.025 seconds

Test and Analysis on the Transverse Gusset Plate Connection to Circular Hollow Section(CHS) of High Strength (고강도 원형강관의 직각방향 거셋플레이트 접합부 실험 및 해석)

  • Lee, Swoo-Heon;Shin, Kyung-Jae;Lee, Hee-Du;Kim, Woo-Bum
    • Journal of Korean Society of Steel Construction
    • /
    • v.24 no.2
    • /
    • pp.163-173
    • /
    • 2012
  • A connection composed of a circular hollow structural section (HSS) has complicated details, and exhibits a very complex local deformation when it reaches the yield stress. Given these circumstances, proposing a simple design equation considering local deformation is difficult. The design equations of the Korea Building Code (KBC 2009) for HSS joints are simple and are very similar to those of the AISC. These design equations limit the maximum yield stress up to 360MPa and yield ratio (yield strength/tensile strength) up to 0.8. This means that the material with yield strength exceeding 360MPa could be used after verification based on the test or rational analysis for the similar connection. This paper introduces an experimental program and finite element analysis (FEA) for the circular hollow section (CHS) with a transverse gusset plate made of high-strength steel (HSB600) or structural steel (SS400) when the joints are subjected to lateral force. Comparison of the design equations with the results of FEA and test may be used for the modification of the design equations.

Perspectives on the Revitalization of Rural Village by Improving Management Scheme for the Dangsan Forest in Singeum Village, Goheung-gun (고흥군 신금마을 당산숲의 관리 개선을 통한 농촌마을 활력 제고방안 고찰)

  • Choi, Jai-Ung;Kim, Dong Yeob;Kim, Mi Heui;Ahn, Ok Sun
    • Journal of Agricultural Extension & Community Development
    • /
    • v.20 no.2
    • /
    • pp.535-554
    • /
    • 2013
  • This study was to investigate the characteristics and management condition of the Singeum village's Dangsan forest, and to seek the revitalization of rural village by improving management scheme. The Dangsan forest in Singeum-ri, Goheung-gun was composed of a Dangsan forest and a Bibo forest. The Dangsan forest was designated as natural monument # 362, and named 'Evergreen forest of Bongnae-myeon, Goheung'. The Dangsan forest area has been disturbed by the building of student training center. Even the local resident couldn't enter the forest due to the fence at the forest boundary except for Dangsan ritual which used to be serviced once a year. The Bibo forest was included in a beach area, and disturbed by lack of management. The Dangsan forest did not stay in good condition with various problems, such as wrong naming as a natural monument and misuse. The driving force of the Dangsan forest maintaining the beauty for several hundred years originated from the conservation of the forest with Dangsan ritual by local residents. Today, the Dangsan forest is in danger of being vanished and not regarded any more as a holy place due to inaccessibility for Dangsan ritual. The Dangsan forest in Singeum village needs to enhance its value as a traditional and cultural landscape, and improving the management scheme will contribute to revitalization of the village.

In-situ Patterning of Magnetic Particles in Microfluidic Channels by Forward/Reverse Local Magnet Arrangement (국소 자기장의 순/역 배열을 이용한 미세유체 채널 내에서의 강자성 입자 패턴 형성)

  • Park, Hyoun-Hyang;Lee, Ji Hae;Yoo, Yeong Eun;Kim, Jung-Yup;Chang, Sunghwan
    • Transactions of the KSME C: Technology and Education
    • /
    • v.3 no.3
    • /
    • pp.217-223
    • /
    • 2015
  • The patterning of microbead in microfluidics channel is a practical technique for application in bio and medical areas. An approach is described for a direct patterning of magnetically active microbeads in microfluidic devices without inner structure. Local magnet arrangements - flat arrangement and stack arrangement - contacting same poles or opposite poles of magnet were utilized for generating trapping magnetic fields. The arrangement of magnets contacting same poles generated isolated patterns by repelling of magnetic field. The flat arrangement of vertically reverse magnet arrays shaped trapping patterns repelling magnetic field line between same poles. Spatially, the stack compositions of magnet arrangements allow diverse isolated trapped patterns of magnetic particles. Trapped magnetic particles in fluidic channels were stable on the $18m{\ell}/hr$ flow conditions and magnetic force of 1.08 mT in the all experiments. This experimental study suggests the simple and versatile methods to pattern magnetic particles, and has potential of wide application to bio and medical area.

A Study on Response System of Marine Pollution Accident by Chemicals in United States (화학물질 해양오염사고에 대한 미국의 방제체제 연구)

  • Choi, Jong-Wook;Lee, Seung-Hwan
    • Proceedings of KOSOMES biannual meeting
    • /
    • 2007.11a
    • /
    • pp.61-67
    • /
    • 2007
  • With an entering into force of OPRC-HNS started in June 14th 2007, establishment of response system in a nationwide scale to take care of accidents is required to respond rapidly and effectively. This necessities drove us to analyze national contingency plan for chemicals including national response system against accidents, which is in operation in the US. Main characteristics of the system are well described as an integrated incident command system with a cooperation of responsibilities facilities, manpower, and technical support. In addition, state anψor local authorities tend to have responsibilities on management of disaster with its response activities. Polluters are also charged to pay expenses 3 times expensive provided state or local authorities are conducted. In general, response activities are conducted by private sectors. However, the government will take action with Superfund if the response capacity is over than the polluters can. However, safety are regarded as a primary factor to be considered in the response activities, and try not to recover any pollutants. Personals belonging to USCG and EPA are required to complete specialized courses to promαe professional skills, and are also welcomed to participate in "certification program"

  • PDF

Coffee Middlemen in Dak Lak, Vietnam: A key stakeholder of coffee value chain as an intermediary of changes in local economies (베트남 닥락성의 커피 중개상인: 지역 경제 변화의 매개체로서 역할을 하는 커피가치 사슬의 주요 이해 관계자)

  • Lee, Sung-Cheol
    • Journal of the Economic Geographical Society of Korea
    • /
    • v.16 no.3
    • /
    • pp.372-388
    • /
    • 2013
  • A series of coffee middlemen has come to be regarded as an exploitative force in the lives of small and poor coffee farmers, which is called 'coyote', controlling production, paying unfair prices for labor and goods, and participating in fraudulent practices to maximize their own profits. However, the reality of gains captured by coffee middlemen in the value chain might be exaggerated and even unfair. Therefore, the main aim of this paper is to reconsider the implication of coffee middlemen for the development of coffee value chain in Vietnam. It also attempts to identify their characteristics by investigating relations among coffee farmers, middlemen and processing/exporting firms. In terms of middlemen's margin in the coffee sub-sector, their margin is quite small when compared to other actors higher in the value chain. Rather, coffee middlemen in Vietnam have played a critical role as an intermediary of change in local economies. More specifically, coffee middlemen in Dak Lak has played a significant role as a market facilitator by stimulating the access of farmers to markets by providing buyers for farmers thanks to changes in institutional environment. Also, they have played a critical role as an agent of sustainable coffee production by encouraging sustainable coffee production in accordance with the demand of processing and exporting firms.

  • PDF

Numerical Study of Turbulent Heat Transfer in Helically Coiled Tubes (나선형 튜브내의 난류 열전달에 대한 수치적 연구)

  • Yoon, Dong-Hyeog;Park, Ju-Yeop;Seul, Kwang-Won
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.36 no.8
    • /
    • pp.783-789
    • /
    • 2012
  • In this study, turbulent flow and heat transfer characteristics in a helically coiled tube have been numerically investigated. Helically coiled tubes are commonly used in heat exchange systems to enhance the heat transfer rate. Accordingly, they have been widely studied experimentally; however, most studies have focused on the pressure drop and heat transfer correlations. The centrifugal force caused by a helical tube increases the wall shear stress and heat transfer rate on the outer side of the helical tube while decreasing those on the inner side of the tube. Therefore, this study quantitatively shows the variation of the local Nusselt number and friction factor along the circumference at the wall of a helical tube by varying the coil diameter and Reynolds number. It is seen that the local heat transfer rate and wall shear stress greatly decrease near the inner side of the tube, which can affect the safety of the tube materials. Moreover, this study verifies the previous experimental correlations for the friction factor and Nusselt number, and it shows that the correlation between the two in a straight tube can be applied to a helical tube. It is expected that the results of this study can be used as important data for the safety evaluation of heat exchangers and steam generators.

Injection of a Denser Fluid into a Rotating Cylindrical Container Filled with Homogeneous Lighter Fluid (균질의 회전유체에 고밀도유체 주입실험)

  • 나정열;황병준
    • 한국해양학회지
    • /
    • v.30 no.4
    • /
    • pp.355-364
    • /
    • 1995
  • A heavy fluid is injected to a rotating cylindrical container of flat or inclined bottom filled with homogeneous lighter fluid. Continuous flow-in and spreading patterns over the bottom of the container are observed and at the same time upper-layer motions induced by the movement of the heavy fluid are traced by thymol blue solution. Regardless of bottom geometry, the injected denser fluid is deflected toward "western wall" and continuous its path along the boundary with radial spreading which occurs in the bottom boundary layer to make a quite asymmetric flow. When the bottom contains a slope(${\beta}$-plane), increased pressure gradient causes the fluid move faster to produce a stronger Coriolis force. This makes the width of the flow narrower than that of f-plane. But, when the denser flow reaches the southern part of the container, a local-depth of denser fluid increases (much greater than the Ekman-layer depth) such that the spreading velocity along the wall is reduced and the interfacial slope increases to make the upper-layer adjust geographically to have oppositely directed upper-layer motion along the interfacial boundary. The role of the denser fluid in terms of vorticity generation in the upper-layer is such that it produces local topographic effect over the western half of the container and also induces vortex-tube stretching which is especially dominant in the f-plane.

  • PDF

Tourism Resource Development for the Activation of Regional Economic and the Roll of Tourism Policy (지역경제 활성화를 위한 관광자원개발과 관광정책의 역할)

  • Kim, Tae-Heon;Park, Suk-Jin
    • The Journal of the Korea Contents Association
    • /
    • v.11 no.5
    • /
    • pp.403-412
    • /
    • 2011
  • This study aims at proposing clear direction of tourism policy through analyzing the correlation between tourism resource, tourism system and activation of regional economic. A total of 283 samples were ultimately collected in survey of 300 researchers from the national and public institutes in provinces Chungchong-do and Kyungsang-do in July 2010 alone. SPSS 15.0 and AMOS 6.0 were used to test the model. Analysis showed that the more regional tourism resources have more significant effect on tourism system and tourist-attracting strategy, and that tourism system exerts influence on tourist-attracting strategy. So it was proved that the tourism policy effects meaningfully on vitalization of regional economic, and it was confirmed that the tourism system is more effective on the energization of regional economic than the tourist-attracting strategy. But the hypothesis has been rejected unexpectedly that tourist attractions have consequences for the activation of regional economic. It establishes the fact that it is useless for regional economy regardless of abundant regional tourism resources, if the tourism policy is not concretely in force. Therefore, Korean government must intercept overissue and overlapping investments on tourism development by the local government and induce qualitative growth of tourism sector through upgrading of development guidelines and the criteria for selecting tourism special zone, regional festival and cultural assets, and its continuous assessment and management. And it is desirable to enforce the connected cooperation projects between local governments and the 5+2 great-sphere economic blocs on government-level.

Workfare in the United Kingdom : A Study on New Deal under the New Labour Government (영국의 근로연계복지에 관한 평가 : 신노동당 정부의 New Deal을 중심으로)

  • Shin, Dong-Myeon
    • Korean Journal of Social Welfare
    • /
    • v.56 no.1
    • /
    • pp.23-43
    • /
    • 2004
  • The purpose of this paper is to evaluate the performance of New Deal under the New Labour government in Britain and examines the nature of New Deal with respect to workfare. The time difference of five years after the New Deal was put into effect shows that New Deal has contributed not only to include the socially excluded groups such as the young unemployed, the long-term unemployed, single parents, and the disabled into the labour market, but also to decrease the amount of income-based benefits providing for working generation. It can be said that the nature of New Deal under the New Labour is near to human capital development model rather than labour force attachment model. New Deal provides the opportunity of policy learning for the countries which pursue the reform of social security system to moving welfare beneficiaries being able to work into jobs. Policy learning can be summed up as follows. First, imposing mutual responsibility and obligations on unemployed person should be accompanied by implementing active labour market programmes of education and job training. Second, the delivery system which administrates workfare programmes should be decentralized in a local society. The cooperation between local government and enterprisers will be critical in implementing various employment programmes and moving unemployed person into jobs. Third, the case management for individual participating in workfare programme is necessary. The personal adviser should continue to provide employment services for the unemployed until he or she get a job and enter the state of self-reliance. Finally, the workfare programme should be firmly backed by the political leadership in order to overcome the oppositions of beneficiary groups under the existing social security system.

  • PDF

Building an Innovation System for Industrial Development in a Knowledge based Economy (산업의 지식집약화를 위한 혁신체제 구축 방향)

  • 김선배
    • Journal of the Economic Geographical Society of Korea
    • /
    • v.4 no.1
    • /
    • pp.61-76
    • /
    • 2001
  • The purposes of this research are to examine the theoretical background and industrial policy issues with regard to building a Innovation System for encouraging industrial competitiveness and fostering regional industry in Korea. Knowledge has become the driving force of economic growth and the primary source of competitiveness in the world market. So since 1990s, Innovation Systems have been put emphasis on as new industrial development strategy in a knowledge-based economy. It can be understood that Innovation System is composed of National Innovation System(NIS) and Regional Innovation System(RIS) and interrelated the concept of clusters and networks, which are contribute to industry development throughout boosting innovation. As for the Korean industrial policy, when the former centralized policy decision making process became decentralized through the implementation of local autonomy, the role of local or state government in relation to regional industrial promotion intensified. But with the impotance of for fostering strategic industry in the region. new industrial policy issues in Korea are needed as follows; $\circled1$ Building a market-oriented support system for industrial cluster through providing the resource of innovation. $\circled2$ Establishing agency for regional industrial development. $\circled3$ Making a evolutionary vision for broader region including 2 or 3 province, $\circled4$ Fostering strategic industry which is selected in term of specialization and potential of the region. The RIS model for industry development is outlined in this paper but policy initiatives for building a RIS have to be extracted from further case studies.

  • PDF