• 한국지반환경공학회 논문집
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• 제3권2호
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• pp.5-14
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• 2002

본 연구에서는 지중내에 설치한 매설관에 작용하는 응력-변형 특성을 분석하였다. 연약지반의 수축과 팽창특성을 고려할 수 있는 Egg-Cam Clay 모델을 소개하였다. 기존에 사용하던 Cam Clay 모델은 연약지반의 수축 및 팽창 특성을 고려하지 못하는 단점이 있기 때문에 Cam Clay 모델을 수정하여 Egg-Cam Clay 모델을 제안하였다. 이와는 별도로 지중내의 매설관에 작용하는 응력-변형을 감소시키기 위하여 지오그리드, EPS 지오폼을 매설관과 함께 설치하였다. 탄소성모델을 이용하여 현장에 시험시공한 여러 단면에 유한요소해석한 결과 긍정적인 효과를 얻었다.

• Structural Engineering and Mechanics
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• 제71권5호
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• pp.469-483
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• 2019

In this paper, an improved mathematical model is presented for the bending analysis of doubly curved functionally graded material (FGM) sandwich rhombic conoids. The mathematical model includes expansion of Taylor's series up to the third degree in thickness coordinate and normal curvatures in in-plane displacement fields. The condition of zero-transverse shear strain at upper and lower surface of rhombic conoids is implemented in the present model. The newly introduced feature in the present mathematical model is the simultaneous inclusion of normal curvatures in deformation field and twist curvature in strain-displacement equations. This unique introduction permits the new 2D mathematical model to solve problems of moderately thick and deep doubly curved FGM sandwich rhombic conoids. The distinguishing feature of present shell from the other shells is that maximum transverse deflection does not occur at its center. The proposed new mathematical model is implemented in finite element code written in FORTRAN. The obtained numerical results are compared with the results available in the literature. Once validated, the current model was employed to solve numerous bending problems by varying different parameters like volume fraction indices, skew angles, boundary conditions, thickness scheme, and several geometric parameters.

• 대한기계학회논문집B
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• 제22권3호
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• pp.326-335
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• 1998

In this study, a steady three-dimensional incompressible turbulent flow within a torque converter was numerically analyzed with the introduction of interrow mixing model. Mixing planes were introduced to exchange the flow informations between two adjacent elements of the torque converter. The mixing planes were installed among three elements of the torque converter. Therefore, in the present method, it could be possible to calculate the flow-filed within the torque converter without any assumption of circulating flow rates or any extension of boundaries toward the upstream and the downstream for each element. The numerically calculated performances of the torque converter were in good agreement with experimental results, and the complex flow patterns were be observed according to design and off-design condition. As a conclusion, it was found that the present numerical method was very effective in the steady flow analysis of torque converters.

• 유통과학연구
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• 제15권1호
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• pp.123-130
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• 2017

Purpose - This research aims to examine the effect of e-business adoption on firm's growth and profitability in the distribution industry. The value added from the distribution industry acts as the cost of other industries. As the distribution industry develops, its stage becomes shorter and the distribution margin becomes smaller. Therefore, e-business is expected to have a different effect on the distribution industry than other industries. Research design, data and methodology - The previous research generally used e-business adoption as an independent variable and firm's performance as a dependent variable. This study elaborated the model using a dynamic panel model that includes the performance variable of the previous year as an independent variable. By employing system GMM (Generalized Method of Moments), the endogeneity problem in the dynamic panel model can be solved. For the analysis, I extracted the distribution companies as the raw data in the National Statistical Office's Business Activity Survey over the period 2006 to 2012. Results - The growth rate of firms adopting e-business was 0.299%p higher than that of the non-adopter. However, only ERP (Enterprise Resource Planning), KMS (Knowledge Management System) and SCM (Supply Chain Management) contributed positively to the growth rate. In the case of profitability, it was 0.04%p higher than the distribution companies that did not adopt e-business. ERP and LMS (Learning Management System) improve profitability, while SCM reduces profitability. Consequently, while ERP improves both growth and profitability, SCM improves growth but reduces profitability. In addition, KMS improves firm's growth only, and LMS does only profitability, showing that each e-business has a differentiated effect. Conclusions - Since the distribution industry has different characteristics from manufacturing and other service industries, the introduction of e-business may not guarantee the growth and profitability of distribution companies. Careful introduction considering the characteristics of the distribution industry is required. In particular, it is necessary to select an e-business meeting the characteristics and needs of a distribution company, and thereafter, it is required for the company's own efforts to internalize it within the system.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권3호
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• pp.254-261
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• 2006

Moderate to severe dentofacial deformities usually require combined orthodontic treatment and orthognathic surgery to obtain the most stable result with optimal function and facial esthetics. Accordingly, the orthodontist and oral maxillofacial surgeon must be able to exactly diagnose existing deformities, establish an appropriate treatment plan, and execute the recommended treatment. Especially, to obtain optimal result of the maxillary surgery, model surgery is essential. But, the preoperatively planned position of the maxillary dental arch often cannot be sufficiently achieved during actual surgery, and deviations in the sagittal and vertical dimensions are common. To achieve three dimensional repositioning of the maxilla exactly, several methods have been introduced so far. Recently Model Repositioning Instrument (MRI, SAM, Inc., $M\ddot{u}nchen$, Germany), one of these methods, has been introduced and applied clinically, which is reported as accurate, effective and prompt method for three dimensional repositioning of the maxilla. This article describes an introduction and a clinical application of this MRI.

• 영어어문교육
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• 제10권2호
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• pp.133-158
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• 2004

The purpose of the present study was to scrutinize computer games that can motivate elementary school students through their interactive "edutainment" effects. The types of elements in computer games that students find interesting as learning media and their impact were studied. The current status of Korean computer games, issues related to learning English, and methods to stimulate the motivation and interest in learning by elementary school students were explored. A computer game model for efficiently teaching English to elementary school students through a connection between computer games and education was suggested. In this model, overall games were designed with the focus on the integration of curriculum and content subjects related to learning activities. For games not to be biased toward entertainment and to have systemized learning steps, the games are composed of an introduction, presentation, practice, production and evaluation, in that order. The model suggested by this plan and composition make it possible to approach learning efficiently with entertaining games based on a systematic learning curriculum. As shown above, developing the model of educational computer games can be seen as an opportunity, which can provide amusement and interests and a broad learning experience as an additional learning method.

• Nuclear Engineering and Technology
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• 제22권2호
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• pp.116-127
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• 1990

SPEAR-BETA코드에서 사용된 핵분열 기체 방출 모델을 핵연료와 피복관 사이의 갭(gap)과 플레넘(plenum) 사이에서 축방향 핵분열 기체 혼합과 균열된 핵연료에 대한 유효 열전도도를 사용함으로써 개량하여, P$_{max}$와$\Delta$P가 변하는 다양한 출력 감발 조건하에서 핵분열기체 방출 거동을 해석하였다. 핵연료 균열의 영향을 고려한 유효 열전도도는 핵연료의 온도 분포와 내부 기체 압력을 계산하는데 사용되었고, 축방향 기체 유동으로 인한 혼합(mixing)과 회석(dilution)효과는 갭의 폭과 열전도도를 해석하는데에 고려되었다. 축방향 기체 유동 효과를 계산하는데 있어서 계산속도를 빠르게 하기 위하여 유한차분법의 하나인 Crank-Nicholson 방법을 사용하였다. 개량된 모델은 다양한 출력 감발 조건하에서 얻어진 실험 자료들과 SPEAR-BETA와 FEMAXl-IV 코드들에서 사용되는 모델들로부터 얻은 결과들을 비교함으로써 검증하였다. 개량된 모델의 결과는 위의 두 코드로부터 얻은 결과 보다는 실험자료들과 잘 일치하였다. 균열된 핵연료에 대해 유효 열전도도를 사용하여 계산한 핵연료의 중심 온도는 균열되지 않은 핵연료의 경우에 비해 20$0^{\circ}C$ 정도보다 높은 값을 나타냈고, 개량된 핵분열 기체 생성물의 분율은 SPEAR-BETA코드에서 얻은 값보다 평균 6% 정도가 높게 나타났다.평균 6% 정도가 높게 나타났다.다.

• 한국전자거래학회지
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• 제18권4호
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• pp.215-240
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• 2013

본 논문은 기업의 모바일 보안기술 도입에 영향을 미치는 특성요인에 관한 이론적 설명력을 제고하기 위해 채택연구들의 이론적 기반이 되었던 혁신확산이론, 혁신저항모델, 기술수용 모델, 정보자산보호 활동이 제시하고 있는 주요 구성개념, 실증연구결과들을 검토하였다. 모바일 보안기술 도입을 위한 특성요인들과 이용의사에 미치는 영향을 검증하기 위해 본 연구모형에서 제시한 17개의 연구가설을 구조방정식모델 분석방법을 사용하여 실증적으로 검증하였다. 연구 결과, 첫째, 혁신저항에 가장 큰 영향을 미치는 모바일 보안기술 특성요인 들은 '적합성', '복잡성', '상대적 이점', '정보자산보호' 순으로 나타났다. 둘째, 이용의사에 영향을 미치는 특성요인은 '상대적 이점', '적합성', '혁신저항', '성과기대'인 것으로 나타났다. 이는 향후 모바일 보안기술 채택 연구의 이론적 배경을 제공하는데 의의가 있으며, 검증된 특성요인 들은 확산주체에게 기존 보안기술과 새로운 모바일 보안기술 간의 정보격차를 완화시키는 정책방향이나 모바일 보안기술도입을 위한 전략적 차원의 시사점을 제공한다.

• 한국항공운항학회지
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• 제17권1호
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• pp.9-16
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• 2009

The analysis of an aircraft flight dynamics is recently very convenient because of the introduction of state-space method and a well-developed package software. The representation of a dynamic system is described as a simple form of matrix calculation and the unique form of model is available for the linear or nonlinear, time variant or time invariant, mono variable or multi variable system with state-space method. And this analysis can be simplified with the specific functions of a package software and it is very simplified to execute the simulation of the dynamic characteristics for an aircraft model with an interactive graphical treatment. The purpose of this study is to develope an educational flight simulator for the students who need to analyze the dynamic characteristics of an aircraft that is primarily to execute the simulation for the analysis of the transient response and frequency response of an aircraft stability. Furthermore the dynamic characteristics of an aircraft motion is set up as dynamical animation tool for the control response on 3-axis motions of an aircraft.

• Spatial Information Research
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• 제14권3호
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• pp.261-270
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• 2006

GIS(Geographic Information System)은 컴퓨터와 인터넷의 출현과 더불어 발전을 해 왔고 이에 맞추어 사용자에게 다양한 서비스를 제공하고 있다. 차세대 Web을 뜻하는 Web 2.0은 불특정다수의 인터넷 사용자가 제공하는 정보가 집약되어 새로운 가치가 창출되는 비즈니스로 발전하고 있다. Web 2.0의 특징으로는 블로그, 롱테일 분포, SNS(Social Networking Service), UCC(User Created Contents), 집단지성 등을 들 수 있다. 본 연구는 Web 2.0의 특징을 이용한 가칭 GIS 2.0을 통해 현재 일방적이고 단순 자료 홍보적 성격의 공간정보제공 방법을 지향하고 쌍방향적이고 일반사용자 참여를 통해 완성될 수 있는 GIS 구축방법으로 전환하여 GIS 도입효과 및 활용을 극대화하는 서비스 모델을 제시한다.