• Proceeding of KASS Symposium
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• 2008.05a
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• pp.95-100
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• 2008

A 4-node assumed strain finite element based on higher order shear deformation theory is developed to investigate the behaviours of symmetric and unsymmetric laminated composite plates. The present element is based on Reddy's higher order shear deformation theory so that it can consider the parabolic distribution of shear deformation through plate thickness direction. In particular, assumed strain method is adopted to alleviate the shear locking phenomena inherited plate elements based on higher order shear deformation theory. The present finite element has seven degrees of freedom per node and denoted as HSA4. Numerical examples are carried out for symmetric and unsymmetric laminated composite plate with various thickness values. Numerical results are compared with reference solutions produced by other higher order shear deformation theories.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.285-291
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• 1992

The purpose of this research, through kinetic analyses and pilot plant experimentation of biofilm filtration reactor, is to study the theoretical equation of head loss in the Biofilm Reactor. The Head loss in the biofilm reactor has occurred due to the biofilm growth and the adhesion to the media surface and stagnation of upflow air bubble, which have caused the pore spaces to become smaller. On a basis of the head loss theory of sand filtration, therefore, the following equation of head loss for the biofilm reactor was proposed from this research results and proved to be possible to apply the equation for practical design of the biofilm filter. $h={\frac{h_o}{L}}{\int}^L_00.58\exp[-4.5){\sigma}_B)][{\frac{1-{\varepsilon}_o+({\sigma}_B)}{1-{\varepsilon}_o}}]^2{[\frac{{\varepsilon}_o}{{\varepsilon}_o-({{\varepsilon}_B)}}]^3dz$ here ${\sigma}_B=0.130+0.001{\theta}$.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.297-297
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• 1998

고속도로의 교통혼잡을 관리하기 위해서는 근본적으로 혼잡지점 상류부의 진입교통량을 제어해야 한다. 이를 위한 효과적인 램프미터링 운영전략이나 고속도로 교통정보제공방안을 수립하기 위해서는 혼잡영향권(대기행렬길이)에 관한 신뢰성 있는 데이터가 반드시 필요하다. 고속도로의 대기행렬길이를 산정하기 위해 일반적으로 충격파이론과 Queueing이론을 제시하고 있다. 그러나, 기존의 충격파 이론을 포물선형의 교통량-밀도관계식을 근거로 하고 있어 충격파간에 발생하는 부수적인 충격파를 해석하는 과정이 수학적으로 불가능하여 실질적인 목적으로 사용할 수 없음은 이미 잘 알고 있는 사실이다. 최근에 이러한 한계를 극복할 수 있는 새로운 방법으로 교통량 밀도간의 관계식을 삼각형으로 가정하고 교통량 대신에 누적교통량을 사용하는 Simplified Theory of Kinematic Waves In Highway Traffic이 개발(Newell, 1993)되었지만, 이 방법을 적용하기 위해서는 기본적으로 대상 고속도로 구간의 교통량-밀도관계식을 규명해야 하는 어려움이 있다.(사실 실시간으로 밀도데이터를 수집하기란 불가능하다.) Queueing이론에서 제시하는 대기행렬은 모두 대기차량이 병목지점에 수직으로 정렬하여 도로를 점유하지 않는 Point Queue(혹은 Vertical stack Queue)로서 실제로 도로상에 정렬된 대기행렬(Real Physical Queue)과는 전혀 다르다. 이미 입증된 바 있어, Queueing이론을 이용함은 타당성이 없다. 이러한 사실에 근거하여 본 연구는 고속도로 대기행렬길이를 산정할 수 있는 모형개발을 위한 기초연구로서 혼잡상태의 연속류 특성을 분석하는데 목적이 있다. 이를 위해, 본 연구에서는 서울시 도시고속도로에서 수집한 실제 데이터를 이용하여 진입램프지점의 혼잡상태에서 대기행렬의 증가 또는 감소하는 과정을 분석하였다. 주요 분석결과는 다음과 같다. 1. 혼잡초기의 대기행렬은 다른 혼잡시기에 비해 상대적으로 급속한 속도로 증가함. 2. 혼잡초기의 대기행렬의 밀도는 다른 혼잡시기에 비해 비교적 낮음. 3. 위의 두 결과는 서로 관계가 있으며, 혼잡시 운전자의 행태(차두간격)과 혼잡기간중에도 변화함을 의미함. 4. 교통변수 중에서 대기행렬길이를 산정하는데 적합한 교통변수를 교통량과 밀도로 판단됨. 5. Queueing이론에서 제시하는 대리행렬길이 산정방법인 대기차량대수$\times$평균차두간격은 대기행렬내 밀도가 일정하지 않아 부적합함을 재확인함. 6. 혼잡초기를 제외한 혼잡기간 중 대기행렬길이는 밀도데이터 없이도 혼잡 상류부의 도착교통량과 병목지점 본선통과교통량만을 이용하여 추정이 가능함. 7. 이상에 연구한 결과를 토대로, 고속도로 대기행렬길이를 산정할 수 있는 기초적인 도형을 제시함.

• Journal of Korea Water Resources Association
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• v.31 no.5
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• pp.575-586
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• 1998

A relaxed similarity theory which can be applied to river models with movable beds is established by modifying existing theory by Einstein and chien(1954). Experimental data collected from river models with movable beds were used to evaluate the applicability of the proposed theory. Effects of similarity of flow, ΔFΔM, and similarity of sediment movement, ΔFs, were examined by analyzing the behaviour of total river-bed change. The results show that the smaller ΔFΔM or ΔFs is, respectively, the larger total sedimentation is. The modified similarity theory established in this study would be useful and practical whenever it is impossible or very difficult to satisfy strict theoretical requirements concerning the river model experiments with movable beds. Keywords : river model, similarity of flow, similarity of sediment movement, sediment transport, river-bed change.

• Journal of the Korean Geographical Society
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• v.50 no.3
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• pp.289-303
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• 2015

This paper is an introductory research to theorize women migrants' positionality in the era of globalization and the feminization of migration. It particularly examines three recent theoretical approaches within feminist studies and their application to the feminist migration study. Migration means a process of continuous negotiations of one's social and material positions within ever changing relations and situations through crossing various borders including national boundaries. Women migrants face multifaceted oppressions due to gendered relation and greater challenges to transform their identities. They embody politics of location through migration. The paper revolves around theories that explore a potential of feminist subjectivation of marginalized women such as female migrants through their identity negotiation and transformation. The theories in questions are Borderlands and the New Mestiza introduced by Gloria $Anzald{\acute{u}}a$, Intersectionality of oppressions, and Transpositions and the Nomadic Subjects by Rosi Braidotti who borrowed the theories of Deleuze and Guattari through feminist critiques. These theories all represent power relations and subject transformations through spatial metaphors. rough spatialized understandings, the paper proposes interlocking relations among space, gender and migration, and explores conceptual tools as well as epistemological insights for Korean migration study.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.4
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• pp.49-58
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• 2018

In recent years, various studies have been carried out on various types of entrepreneurship and comparative activities according to policy efforts and support such as the activation of a bachelor's degree in the establishment of a university, and attention has been paid to the fact that the participation and the educational effect of the students may be different depending on the type. The purpose of this study is to investigate entrepreneurial motivation, entrepreneurship, and entrepreneurial intention in the case of experiential entrepreneurship class focusing on the theoretical-oriented general entrepreneurship class, And the effect of entrepreneurship on entrepreneurial intention. The data were collected and empirical analysis was conducted to compare the difference between the two groups. The results of this study are as follows: First, out of the motivation factors of entrepreneurs, entrepreneurship education, achievement desire, human network, self - esteem, etc. We can confirm that the motivation of entrepreneurs is recognized more greatly. Second, the entrepreneurship factor was not significantly different from the perception between experiential entrepreneurship lecture and theoretical entrepreneurship learner. Third, experiential entrepreneurship learner perceived more willingness to start business than theoretical entrepreneurship learner. Finally, among the entrepreneurship motivation factors, among the entrepreneurship education, achievement desire and entrepreneurship factor, the risk sensitivity affects the entrepreneurial will. This study suggests that the direction of entrepreneurial education focused on quantitative expansion and the creation of qualitative effects of entrepreneurship education are needed. In the future, it will provide policy implications for revitalizing experiential entrepreneurship education In addition, it can contribute to the diffusion of research on the effect of entrepreneurship education.

• Journal of Korea Water Resources Association
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• v.49 no.10
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• pp.887-901
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• 2016

Cohesive sediments form flocs through the flocculation process. The size and density of floc are variable whereas those of a fine sediment are always assumed to be constant. The settling velocity, one of main factors of sediment transport, is determined by size and density of particle. Therefore, the flocculation process plays an important role in transport of cohesive sediment. It is of great difficulty to directly measure the density of floc in the field due to technical limitation at present. It is a popular approach to estimate the density of floc by applying the fractal theory. The main assumption of fractal theory is the self-similarity. This study aims to examine the applicability of fractal theory to cohesive sediment in small rivers of Korea. Sampling sediment has been conducted in two different basins of Geum river and Yeongsan river. The results of settling experiments using commercial camera show that the sediment in Geum river basin follows the main concept of fractal theory whereas the sediment in Yeongsan river basin does not have a clear relationship between floc size and fractal dimension. It is known from this finding that the fractal theory is not easily applicable under the condition that the cohesive sediment includes the high content of organic matter.

• The Journal of Korean Philosophical History
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• no.35
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• pp.109-129
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• 2012

At this point, in Confucianism's schools debated about analysis for early theory and latterly it of nature between human and animal in Nongam Kim Changhyob's Confucianism. Oh Heeshang argued early theory about Shanguzaezungyongmunmok, written by Kim Changhyob, and establishment of theory about Yokuonyudozaelonshabyonnokbyon, written by him. Kim Changhup, brother of Kim Changhyob, argued so early theory about Shanguzaezungyongmunmok. O Yubong, student of Kim Changhyob, argued establishment of theory about Sobyon and Zabzee, written by Kim Changhyob. While, Yim Songzu argued early theory and establishment of theory about Zabzee. As a result, presenting researchers argued the same as. That is, they interpret early theory about difference of nature between human and animal in Kim Changhyob. they interpret about the same of nature between human and animal in it. However, Kim Changhyob wrote difference of nature between human and animal in Shanguzaezungyongmunmok. While, he wrote difference it and the same it in Yokuonyudozaelonshabyonnokbyon. He thought the same li between human and animal. However, he thought difference hyongki them. Furthermore, He wrote difference it and the same it in Zabzee. Therefore, they had depended on Kim Changhyob. As a result, posterity scholars interpreted early theory and establishment of theory about his theory. they depended on his authority. However, he changed himself theory.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.2
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• pp.427-435
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• 2017

Most of the domestic city buses are equipped with the pressure vessels subjected to internal pressure applied by compressed natural gas. Pressure vessels subjected to internal pressure are used in various forms and purposes. Fuel is explosive and has flammable high pressure. The damage of the pressure vessel causes many property damage and loss of life. Safe design for pressure vessel is always necessary. Due to these reasons, many studies using finite element analysis have been conducted. In this paper, the stresses of cylindrical vessel and spherical dome were analyzed using ANSYS, a finite element analysis software. In order to verify the validity of the analysis, a model with a perfectly spherical shape of the dome was designed and observed. Based on the ASME standard in used, stress distribution was also analyzed for models designed with compressed natural gas(CNG). The FEM analysis software agreed with the theory when the dome shape was perfectly spherical. The model designed based on the ASME specification theory, stress concentration occurred in the knuckle part.

• Journal of Korea Game Society
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• v.15 no.5
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• pp.143-152
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• 2015

Unlike simulating general 'particle-based fluid explosion', simulating fluid with elasticity requires various experimental methods in order to show the realistic deformation of the matter. The existing studies on particle-based viscoelastic fluid only focused on matters' plastic deformation which can be found in mud or paint, based on the maximum distortion energy theory and maximum shear stress theory. However, these former researches could not simulate the brittle deformation which can be seen from silicon or highly elastic rubber when great external forces above limits are applied. This study suggests a brittle simulation method based on the Coulomb-Mohr theory, the idea that a yield occurs when maximum stress on a matter reaches to its rupture stress. This theory has a significant difference from the existing particle-based simulations which measures the forces on a matter by length or volume. Using a strong-elastic semifluid which Coulomb-Mohr theory is applied, realistic deformation process of a matter was observed as its forced surface reached to the rupture stress. When semifluid hit the ground, the impact of deformation can be explained by using Coulomb-Mohr theory.