• 동아시아경상학회지
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• 제6권1호
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• pp.42-46
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• 2018

Purpose - The purpose of this study was to review and analyze EAJBE (The East Asian Journal of Business Economics) of EABEA (The East Asia Business Economics Association) and all of their published articles of 2013 to 2017 and to revise and update the existing publication standards and practices in order to improve the overall quality and reputation of EAJBE. Research design, data, and methodology - This paper applied an analytical approach, a case study method, to analyze and examine the published articles and the publication standards and practices of EAJBE (East Asian Journal of Business Economics) from their first publication. Results - The EAJBE has been issuing academic journals four times a year since its foundation. Although it is a journal based in Korea, overseas scholars publish articles steadily compared to other academic journals and the EAJBE raises the level of globalization. The level of internationalization of association's management and editorial members is also high, making the overall academic journal more cosmopolitan. Conclusions - Although the EABEA (The East Asia Business Economics Association) is a newly formed, the association is actively managing the academic community and making two major goals for the development of the academic journal. First, this journal is actively attracting overseas scholars, and is raising the level of internationalization. As an integrated academic conference is held with overseas scholars, they actively exchange with overseas scholars by contributing and publishing their papers. Second, it is seeking to establish national and international ties by publishing the papers of Korean scholars as well as abroad and holding academic contests regularly.

• Spatial Information Research
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• 제9권2호
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• pp.185-206
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• 2001

셀룰라 오토마타(CA)는 복합체(complex system)의 특성과 행태를 분석하거나 시뮬레이션 하기 위해서 고안된 이론적 체계로 자연과학 및 공학의 여러 분야에서 연구되어왔다. 최근 GIS 분야에서는 CA가 가지고 있는 시공간적 동적 모델 구현의 개념적 우수성과 래스터 GIS와의 유사성에 근거하여 CA와 GIS를 이용한 다양한 모델링 연구가 발표되고 있다. 그러나 대부분의 연구에서 개발된 CA모델들은 GIS의 제한된 기능을 바탕으로 구현되어 CA가 가지고 있는 장점들을 충분히 활용하고 있지 못하며 실제적인 모델링 연구에 활용될 수 있는 통합시스템이 개발되어 있지 않다. 본 연구에서는 CA를 GIS의 모델링 엔진으로 결합하여 동적 공간 모델링 혹은 시뮬레이션을 수행할 수 있는 범용의 CA-GIS 통합시스템을 개발하였다. 이러한 CA-GIS 통합시스템을 개발하였다. 이러한 CA-GIS 통합시스템은 GIS의 동적 공간 모델링 기능을 대폭 보완할 수 있을 것으로 기대되며 도시성장 예측모델 개발과 같은 실제적인 모델링 연구 수행에 효과적인 도구로 활용될 수 있을 것으로 판단된다.

• Spatial Information Research
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• 제20권5호
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• pp.15-24
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• 2012

이 연구는 공간인지 이론을 기반으로 하여 최근에 급격히 발달하고 있는 길찾기 목적의 웹지도 효과를 측정하기 위한 기본 개념과 평가틀을 설정하고 정량적 분석방법을 제안하는 것을 목적으로 한다. 이를 위해 특정 지도사용상황에서 길찾기 과제를 수행한 후 지도사용으로 얼마나 효과적으로 공간인지가 이루어졌는지를 측정하는 '인지적 지도사용효과'의 개념과 정확성, 신속성, 자신감의 분석항목을 기반으로 하는 평가틀을 제안하였다. 제안한 평가틀을 실증적으로 검증하기 위해 실험조사를 실시하고, 실험 결과물인 인지지도를 2차원 회귀분석 방법을 적용하여 실험결과를 계량화하였다. 분석결과, 공간을 정확하게 인식하거나 빠르게 회상하는 데에는 지도표현방법보다 사용자의 특성과 반복적인 지도사용 등의 요소가 영향을 미치며, 2차원 지도와 3차원 지도를 동시에 참조하는 경우 공간인지에 대한 자신감이 낮은 것으로 나타났다. 이 연구결과는 효과적일 것이라고 예상되는 새로운 지도표현방법이 실제로 그렇지 않거나, 사용자마다 효과적이라고 판단하는 지도표현방법이 다른 이유에 대한 근거를 제공해 준다.

• Structural Engineering and Mechanics
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• 제17권5호
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• pp.691-706
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• 2004

The paper presents shear lag parameters for beam-to-column connections in steel box piers. Previous researches have analyzed beam-to-column connections in steel piers using a shear lag parameter ${\eta}_o$ obtained from a simple beam model, which is not based on a reasonable design assumption. Instead, the current paper proposes a cantilever beam model and has proved the effectiveness through theoretical and experimental studies. The paper examines the inaccuracy of the previous researches by estimating the effective width, the width-span length ratio L/b, and the sectional area ratio S of a cantilever beam. Two different shear lag parameters are defined using the cantilever model and the results are compared each other. The first type of shear lag parameter ${\eta}_c$ of a cantilever beam is derived using additional moments from various stress distribution functions while the other shear lag parameter ${\eta}_{eff}$ of a cantilever beam is defined based on the concept of the effective width. An evaluation method for shear lag stresses has been investigated by comparing analytical stresses with test results. Through the study, it could be observed that the shear lag parameter ${\eta}_{eff}$ agrees with ${\eta}_c$ obtained from the $2^{nd}$ order stress distribution function. Also, it could be observed that the shear lag parameter ${\eta}_c$ using the $4^{th}$ order stress distribution function almost converges to the upper bound of test results.

• Interaction and multiscale mechanics
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• 제3권1호
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• pp.95-110
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• 2010

In recent years, study of the static response of pavements to moving vehicle and aircraft loads has received significant attention because of its relevance to the design of pavements and airport runways. The static response of beams resting on an elastic foundation and subjected to moving loads was studied by several researchers in the past. However, most of these studies were limited to steady-state analytical solutions for infinitely long beams resting on Winkler-type elastic foundations. Although the modelling of subgrade as a continuum is more accurate, such an approach can hardly be incorporated in analysis due to its complexity. In contrast, the two-parameter foundation model provides a better way for simulating the underlying soil medium and is conceptually more appealing than the one-parameter (Winkler) foundation model. The finite element method is one of the most suitable mathematical tools for analysing rigid pavements under moving loads. This paper presents an improved solution algorithm based on the finite element method for the static analysis of rigid pavements under moving vehicular or aircraft loads. The concrete pavement is discretized by finite and infinite beam elements, with the latter for modelling the infinity boundary conditions. The underlying soil medium is modelled by the Pasternak model allowing the shear interaction to exist between the spring elements. This can be accomplished by connecting the spring elements to a layer of incompressible vertical elements that can deform in transverse shear only. The deformations and forces maintaining equilibrium in the shear layer are considered by assuming the shear layer to be isotropic. A parametric study is conducted to investigate the effect of the position of moving loads on the response of pavement.

• Geomechanics and Engineering
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• 제7권4호
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• pp.403-430
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• 2014

Shale gas formations exhibit strong mechanical and strength anisotropies. Thus, it is necessary to study the effect of anisotropy on the hydraulic fracture initiation pressure. The calculation model for the in-situ stress of the bedding formation is improved according to the effective stress theory. An analytical model of the stresses around wellbore in shale gas reservoirs, in consideration of stratum dip direction, dip angle, and in-situ stress azimuth, has been built. Besides, this work established a calculation model for the stress around the perforation holes. In combination with the tensile failure criterion, a prediction model for the hydraulic fracture initiation pressure in the shale gas reservoirs is put forward. The error between the prediction result and the measured value for the shale gas reservoir in the southern Sichuan Province is only 3.5%. Specifically, effects of factors including elasticity modulus, Poisson's ratio, in-situ stress ratio, tensile strength, perforation angle (the angle between perforation direction and the maximum principal stress) of anisotropic formations on hydraulic fracture initiation pressure have been investigated. The perforation angle has the largest effect on the fracture initiation pressure, followed by the in-situ stress ratio, ratio of tensile strength to pore pressure, and the anisotropy ratio of elasticity moduli as the last. The effect of the anisotropy ratio of the Poisson's ratio on the fracture initiation pressure can be ignored. This study provides a reference for the hydraulic fracturing design in shale gas wells.

• 대한기계학회논문집A
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• 제34권11호
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• pp.1749-1755
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• 2010

파워 글라스 시스템의 특성은 주로 윈도우 레귤레이터의 거동 특성과 글라스 런에 의한 저항에 의해 결정되며, 시험 결과 분석을 통해 시스템의 성능을 예측한다. 본 논문에서는 시험적인 방법의 한계를 해결하기 위해, 익스플리시트 코드를 사용한 해석적 방법을 제안하였다. 해석 모델에 사용한 글라스 런은 무니-리블린 모델을 사용하여 모델링 하였고, 다양한 조건에서의 마찰 시험을 실시하여 마찰계수를 구하였다. 또한, 윈도우 레귤레이터 파트의 메커니즘은 패스트 벨트 시스템과 슬립 링요소를 사용하여 모델링 하였고, 상승 시 발생하는 전류와 하중과의 상관관계 분석을 통해 레귤레이션 메커니즘의 신뢰성을 검증하였고, 모터의 특성을 고려하여 신뢰성 있는 글라스 상승 시간을 예측하였다.

• 대한조선학회논문집
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• 제28권2호
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• pp.174-186
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• 1991

해상 및 육상구조물에는 다수의 보 및 봉요소들로 구성된 골조구조계 또는 이에 감쇠가 있는 스프링·질량계로 유추될 수 있는 부가물이 부가된 복합적구조계가 있다. 이와 같은 계의 진동해석을 효율적으로 수행하기 위해 receptance방법을 근간으로 하는 해석적 방법을 제시했다. 자유진동특성 및 집중기진력에 대한 응답을 계산하기 위해 균일단면 Timoshenko보 및 봉의 receptance를 유도하고 이들을 각종 부가물들의 receptance와 함께 합성하는 방법을 제시했다. 이때 복합계의 감쇠특성도 각 구성요소 감쇠특성의 합성에 의해 산정된다. 또한 지지부에 변위기진이 작용하는 경우에 대한 동적응답계산을 수행할수 있도록 균일단면 Timoshenko보 및 봉의 Support Displacement Transfer Ratio를 유도하고 이를 다른 구성요소들의 receptance와 합성하는 방법도 제시했다. 이와같은 방법은 특히 부분적 설계변수변경에 따른 동특성치 재산정예 있어서 매우 편리하다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1171-1176
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• 2005

The latest technical development of steel plate girder railway bridge are developing in ways to maximize its durability of materials in use of high strength steel and efficiency of maintenance and management by the introduction of simplified and standardization ideas. In addition to this, it is also expected to reduce the cost of bridge construction and to simplify the process of bridge manufacturing. Referring to this, composite few plate girder railway bridge is highly recommendable that is very economical with the fine exterior. In this paper, it will analyse the variation of dynamic behavior of existing composite few plate girder railway bridge with ballast caused by modified Slab Track through interpretation of limited enzyme in order to obtain the existing data for improvement of Slab Track system from Ballast Track system. Consequently, it can help maximize economic efficiency and structural capability. As a results, although the natural frequency by modified Slab Track are decreased, it is hardly influencing on the safety of railway bridges. It is also evident in the case of slab deck with a reduced scale in comparison with Ballast Track. Therefore, it is expected to reduce the cost of a railway bridge plan. And, it can expect the synergistic effect of the ensure long term durability of bridge caused by decreased stresses of bottom flange due to reduced dead load. As a result, the analytical study are carried out to investigate the composite few plate girder railway bridge could be the optimal design method for the dynamic safety of a girder section.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권1호
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• pp.66-77
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• 2010

Improvement in breakdown voltage ($BV_{ds}$) and speed of the device are the key issues among the researchers for enhancing the performance of HEMT. Increased speed of the device aspires for shortened gate length ($L_g$), but due to lithographic limitation, shortening $L_g$ below sub-micrometer requires the inclusion of various metal-insulator geometries like T-gate onto the conventional architecture. It has been observed that the speed of the device can be enhanced by minimizing the effect of upper gate electrode on device characteristics, whereas increase in the $BV_{ds}$ of the device can be achieved by considering the finite effect of the upper gate electrode. Further, improvement in $BV_{ds}$ can be obtained by applying field plates, especially at the drain side. The important parameters affecting $BV_{ds}$ and cut-off frequency ($f_T$) of the device are the length, thickness, position and shape of metal-insulator geometry. In this context, intensive simulation work with analytical analysis has been carried out to study the effect of variation in length, thickness and position of the insulator under the gate for various metal-insulator gate geometries like T-gate, $\Gamma$-gate, Step-gate etc., to anticipate superior device performance in conventional HEMT structure.