• 한국구조물진단유지관리공학회 논문집
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• 제19권2호
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• pp.76-83
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• 2015

본 연구의 목적은 고충진 합성목재를 이용하여 친환경 모듈러 돔 구조시스템을 개발하고 부재와 절점을 모듈화하여 실제 구조체을 제작하는 것이다. 기존의 합성목재에 비해 높은 70% 목분함량 합성목재를 돔 구조모델의 부재로 이용하였고, 정이십면체 기반 지오데직 돔의 기하학적 특성을 분석하여 절점과 부재를 모듈화 하였다. 돔의 제작을 위한 모듈화와 실제 구조물의 제작과정의 연구결과로부터 6가지 절점과 3개의 부재종류의 모듈러 돔에 대한 적용성을 검토할 수 있었다. 또한 해석결과에서 최저차 좌굴모드는 경계부의 절점에서 절점좌굴이 예상되었다.

• Korea-Australia Rheology Journal
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• 제20권2호
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• pp.59-63
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• 2008

A theoretical model was developed to describe the flow behavior of a filled polymer in the packing stage of reaction injection molding and predict the residual stress distribution of thin injection-molded parts. The model predictions were compared with experiments performed for phenol-formaldehyde resin filled with wood dust and cured by urotropine. The packing stage of reaction injection molding process presents a typical example of complex non-isothermal flow combined with chemical reaction. It is shown that the time evolution of pressure distribution along the mold cavity that determines the residual stress in the final product can be described by a single 1D partial differential equation (PDE) if the rheological behavior of reacting liquid is simplistically described by the power-law approach with some approximations made for describing cure reaction and non-isothermality. In the formulation, the dimensionless time variable is defined in such a way that it includes all necessary information on the cure reaction history. Employing the routine separation of variables made possible to obtain the analytical solution for the nonlinear PDE under specific initial condition. It is shown that direct numerical solution of the PDE exactly coincides with the analytical solution. With the use of the power-law approximation that describes highly shear thinning behavior, the theoretical calculations significantly deviate from the experimental data. Bearing in mind that in the packing stage the flow is extremely slow, we employed in our theory the Newtonian law for flow of reacting liquid and described well enough the experimental data on evolution of pressure.

• Journal of the Korean Data and Information Science Society
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• 제20권4호
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• pp.673-684
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• 2009

텔레마케팅의 영업특성상 전화 응대를 한 고객에게 초기 적절한 상품을 추천하여 보험가입을 유치하는 것이 가장 중요하다. 따라서 고객의 선호상품 및 선호시간을 고려한 고객 선별과 타겟팅을 어떻게 진행하느냐에 따라 거수보험료 차이가 발생한다. 본 연구는 데이터마이닝 기법 중 로지스틱회귀모형을 이용하여 생명보험사 아웃바운드 텔레마케팅 영업을 지원하는데 있어서 그 효과를 검증하고자 하였다. 기존의 가입상품에 대한 고객반응정보와 L생명보험사 영업 전략에 따라 연령을 구간화하고 가족사랑보험, 상해보험, 암보험 상품에 대한 모델링을 진행하였다. 설정된 모델을 바탕으로 캠페인 진행시 기존 마케팅 방식과 모델방식으로 고객을 추출하고 실행결과를 통해 모델의 우수성을 입증하였다. 또한 시간이 지남에 따라 설정한 모델이 노후화되고 영업이익이 줄어듦에 따라 지속적으로 영업이익을 극대화 할 수 있도록 모델갱신주기를 도출하였다.

• 한국BIM학회 논문집
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• 제6권2호
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• pp.39-46
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• 2016

While institutional matters such as improvement on Basic Guidelines for Construction Safety are greatly concerned to reduce falling accidents at construction sites, there are short of studies on how to practically predict accident signs at construction sites and to preemptively prevent them. As one of existing accident prevention methods, it was attempted to build the early warning system based on standardized accident scenarios to control the situations. However, the investment cost was too high depending on the site situation, and it did not help construction workers directly since it was developed to mainly provide support operational work support to safety managers. In the long run, it would be possible to develop the augmented reality based accident prevention method from the worker perspective by extracting product information from BIM, visually rendering it along with site installation materials term and comparing it with the site situation. However, to make this method effective, the BIM model should be implemented first and the technology that can promptly process site situations should be introduced. Accordingly, it is necessary to identify risk signs through lightweight image processing to promptly respond only with currently available resources. In this study, it was intended to propose the system concept that identified potential risk factors of falling accidents by histogram equalization, which was known as the fastest image processing method presently, used visual words, which could enhance model classification by wording image records, to determine the risk factors and notified them to the work manager.

• 에너지공학
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• 제19권3호
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• pp.188-194
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• 2010

DCFC는 가스 터빈이나 엔진과 달리 탄소를 사용하여 전기화학반응을 통해 직접 전기를 생산하는 연료전지이며, 주요 특징으로 기존의 발전설비 보다 높은 효율과 낮은 배기 배출물을 발생한다. 본 연구에서는 간단한 열역학 평형 해석을 통해 CO와 $CO_2$가 이론 기전력에 미치는 영향을 확인하였으며, 2차원 CFD 해석 방법을 이용하여 온도에 따른 반응 생성물 변화를 살펴보았다. 그 결과, CO 생성 반응(Boudouard 반응)을 동시에 고려한 이론 기전력 값은 $CO_2$ 생성 반응만 고려한 값(약 1.02 V)보다 크며, 특히 온도가 증가할수록 그 값이 증가함을 보여주었다. 2차원 수치해석 결과를 통하여서 Boudouard 반응이 고온으로 갈수록 중요하며, 비활성 기체로 인하여 Boudouard 반응이 지연됨을 확인하였다.

• 한국의류학회지
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• 제30권9_10호
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• pp.1400-1412
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• 2006

As PB market segments into premium market, PBs were drawing attentions in terms of creating profits as well as a means to differentiate building up store identity. The purpose of this study makes a comparative study on the difference of consumer attitude formation process in discount store and home-shopping distribution channel which are recently on the upswing. This paper investigated the consumer's attitude formation on the private apparel brand. Subjects of this study were consumers in their $20s{\sim}40s$ who are main customer groups of PBs. The data were analyzed by Structural Equation Modeling and Multi-Group Analysis of Amos 5.0 to verify the difference of the path between store PB and premium PB. Following are the results of the study. Consumer attitude formation path on PB grades showed statistically noticeable difference. In discount store PB, store evaluation didn't directly influence on consumer attitude formation but showed indirect effect. On the other hand, in home shopping premium PB case, product evaluation directly influenced on consumer attitudes with store evaluation. Hedonic attitude dimension connected with behavioral attitude(purchase intention) revealed difference in path. Also consumer's evaluation on variables in model turned out to be different according to brand grade.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.844-847
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• 2005

A seamless analysis of complex geometry is one of greatly interesting topic. However, there are still gaps between the industrial applications and fundamental academic studies owing to time consuming modeling process. To resolve this problem, an auto mesh generation program based on grid-based approach has been developed for IT-product in the present study. At first, base mesh and skin mesh are generated using the information of entities which extracted from IGES file. Secondly the provisional core mesh with rugged boundary geometry is constructed by superimposing the skin mesh as well as the base mesh generated from the CAD model. Finally, the positions of boundary nodes are adjusted to make a qualified mesh by adapting node modification and smoothing techniques. Also, for the sake of verification of mesh quality, the hexahedral auto mesh constructed by the program is compared with the corresponding tetrahedral free mesh and hexahedral mapped mesh through static finite element analyses. Thereby, it is anticipated that the grid-based approach can be used as a promising pre-processor for integrity evaluation of various IT-products.

• 대한원격탐사학회지
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• 제29권3호
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• pp.275-291
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• 2013

Monitoring the global Gross Primary Pproduction (GPP) is relevant to understanding the global carbon cycle and evaluating the effects of interannual climate variation on food and fiber production. GPP, the flux of carbon into ecosystems via photosynthetic assimilation, is an important variable in the global carbon cycle and a key process in land surface-atmosphere interactions. The Moderate-resolution Imaging Spectroradiometer (MODIS) is one of the primary global monitoring sensors. MODIS GPP has some of the problems that have been proven in several studies. Therefore this study was to solve the regional mismatch that occurs when using the MODIS GPP global product over Korea. To solve this problem, we estimated each of the GPP component variables separately to improve the GPP estimates. We compared our GPP estimates with validation GPP data to assess their accuracy. For all sites, the correlation was close with high significance ($R^2=0.8164$, $RMSE=0.6126g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$, $bias=-0.0271g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$). We also compared our results to those of other models. The component variables tended to be either over- or under-estimated when compared to those in other studies over the Korean peninsula, although the estimated GPP was better. The results of this study will likely improve carbon cycle modeling by capturing finer patterns with an integrated method of remote sensing.

• 한국의상디자인학회지
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• 제12권3호
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• pp.43-55
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• 2010

The major advantages to use CAD System are that it reduce time and effort to manufacture products, and also can demonstrate the condition of the final product prior to the actual manufacturing process of the selected design using the simulation programs in CAD system. Specially in weave design, for use as Computer-Aided Weaving system, the complicated Dobby weave can figured out easily through calculating the complex weave plans of multi shafts. As to one of dobby weave structures, Supplementary warp is the warp threads which are in addition to the regular warps of the woven fabrics, and used for decorating the band or expressing some patterns. The purpose of this study is to research the weave design of Supplementary warp using Computer-Aided Weaving system, which is dobby weave design program of Weave Point. For performing this design study, it was researched the classified woven fabrics depending upon weaving processing, Computer-Aided Weaving system, and the characteristic of Supplementary warp fabrics. On the basis of the theoretical research, Supplementary warp was worked for the 24-shafts AVL computer dobby loom that applied to the various patterned images. The design work was done by Weave Point program of dobby weave, and simulated to fabrics before woven into the computer dobby loom. To see the visual images of fashion items, these simulated bobby fabrics were processed by three-dimension modeling through YoungWoo CNI CAD system. All the patterns of the Supplementary warp in this study could be applied for decorating the fashion clothing and accessories.

• 대한기계학회논문집A
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• 제38권10호
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• pp.1163-1169
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• 2014

본 연구에서는 자동차 서스펜션 구조에 일반적으로 사용되는 용접부 형상에 대하여 굽힘 하중에 의한 피로수명을 예측할 수 있는 절차를 개발하였다. 이종 재료로 이루어진 실제 제품 용접 연결부의 피로수명 예측을 위해, 복잡한 형상의 제품을 단순화한 용접 시편을 설계하고 이에 대한 굽힘 피로 시험을 진행한 후 모멘트-피로수명(M-N) 선도를 제시하였다. 응력 집중에 의한 영향을 분석하기 위해 시편의 형상을 모델링 한 후 정적 하중에 대한 유한요소해석을 수행하여 균열 발생부의 응력을 구하고 응력-피로수명(S-N) 선도를 제시하였다. 유한요소해석을 통해 구한 응력과 이론 계산을 통해 구해준 응력을 이용하여 응력집중계수를 계산하였고, 응력집중부의 피로평가 방법 개선을 위해 보편적으로 사용되는 피로노치계수 평가법과 굽힘 피로 시험 결과를 비교 검토하였다. 그 결과, 이종 재질 용접 연결부의 정확한 피로 수명평가를 위해서는 기하형상을 고려한 피로노치계수 평가 분석뿐만 아니라 두 소재의 맞대기 용접 시편에 대한 피로 시험을 수행해 주어야 할 것으로 판단된다.