• 대한기계학회논문집B
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• 제34권2호
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• pp.99-103
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• 2010

다공성 매질상에서 유체와 용질의 이동은 Mobile zone과 Immobile zone으로 분리해서 분석하는 Mobile-Immobile Zone Model을 이용하여 쉽게 현상을 구현할 수 있었으나 본 연구에서는 2차원 4각형태의 pore 상에서 확산주도영역(Immobile zone)으로 들어가고 나오는 용질의 확산에 관한 새로운 Analytic solution을 유도하여 기존 MIM Zone model과 비교 분석하였다. 새롭게 유도된 Analytic solution은 기존의 MIM model 과 비교했을때 충분히 오랜시간이 경과한 후에는 해의 일치를 보이지만 MIM model의 경우 초기 농도값이 주입된 실제 농도보다 약 20 % 낮게 나타난다. Mass-transfer 계수, $\alpha$는 일반적으로 시간의 흐름에 따라 감소하게 되는데 일정 시간이 경과하게 되면 안정화 되고 일정함을 유지하며 그 시간은 무차원으로 약 ${\tau}_0=0.15$이다. 또한 $\alpha$는 분자확산과 비례하며 Immobile 영역의 깊이와 반비례하는 반면 작은 시간이 경과한 후에는 시간에 종속되어진다.

• The Journal of Asian Finance, Economics and Business
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• 제7권1호
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• pp.259-268
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• 2020

The purpose of this study is to examine the predictive effects of intuition, business analytic, networking capabilities on innovation performance. The data was collected using a cross-sectional quantitative survey. A total of 292 useable responses were collected from Thai Processed Food Exporters (TPFE). The findings also indicated that the hypothesized relationships between the independent and dependent variables fit the empirical data. Specifically, it is revealed that strategic intuition, business analytic capabilities, network-based capabilities and dynamic capabilities had a direct effect on dynamic strategy. They also had statistically significant direct and indirect effects on dynamic performance. Based on the results of the correlation test, the researchers developed a dynamic capability model for the development of the dynamic performance of the operators, which included concepts, principles, methods, tools and guidelines. Furthermore, the impacts of intuition, business analytic, networking capabilities on dynamic strategy are also examined in this study. It makes a considerable contribution to the existing literature on dynamic strategy of TPFE, particularly in regards to explaining the performance.

• 한국전산구조공학회논문집
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• 제28권3호
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• pp.325-333
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• 2015

최근들어 철근콘크리트 슬래브와 벽의 연결부에 적용 가능한 열교차단장치에 대한 연구가 다수 수행되고 있다. 이에 본 연구에서는 열교차단장치가 적용된 슬래브의 균열 전 탄성거동, 균열 후 항복거동 및 극한강도까지 적용이 가능한 해석모델을 제안하고, 실험결과와의 비교를 통하여 제안 모델의 정확도를 검증하고자 하였다. 해석모델은 변형률 적합조건과 힘의 평형개념을 적용하였으며, 이 때 구성 재료의 응력-변형률 관계는 재료실험 결과를 적용하였다. 해석모델의 신뢰성 검증을 위해 모멘트-곡률 관계, 하중단계에 따른 중립축을 실험결과와 비교하였으며, 제안된 해석모델은 실험결과로 획득한 전체적인 휨거동 양상과 거의 일치함을 확인할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1009-1013
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• 2007

To do a HRTF customization, researchers used a spherical head model for modeling the head block of structural modeling of HRTF, which is the one of the technique for HRTF customization, because of its simplicity. In this paper, an analytic spheroidal HRTF caused by an incident point source will be introduced. Using proposed spheroidal HRTF, near-field HRTF customization can be applicable through a structural modeling of HRTF. To see the necessity of sheroidal head model, comparison of two analytic solutions, which are classical spherical HRTF and proposed spheroidal HRTF, will be shown. On the view point of ITD, optimal head model which matches with the measured ITD of KEMAR HRTF can be obtained. ITD results show that there are only slight differences between spherical and spheroidal head model. Magnitude comparison is made by constructing head model using measured head size. Although magnitude comparison is not studied between optimal models, the results of 24 of 36 subjects are shown that spheroidal head model matches notch frequency pattern of measured HRTF better than those of spherical one, where the sound source is at contralateral position.

• 한국자동차공학회논문집
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• 제2권1호
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• pp.38-50
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• 1994

To improve the efficiency of internal combustion engines, it is necessary to understand mixed air-fuel in-cylinder flow processes accurately at intake and compression strokes. There is experimental and numerical methods to analyse in-cylinder flow process. In numerical method, standard $k-{\varepsilon}$ model with wall function was mostly adopted in in-cylinder flow process. But this type model was not efficiently predicted in the near wall region. Therefore in the present study, low Reynolds number $k-{\varepsilon}$ model was adopted near the cylinder wall and standard $k-{\varepsilon}$ model in other region. Also QUICK scheme was used for convective difference scheme. This study takes axisymmetric reciprocating model engine motored at 200rpm with a centrally located valve, incorporated 60 degree seat angie, and flat piston surface excluding inlet port. Because in-cylinder flow processes are undergoing unsteady and compressible, averaged cylinder pressure and inlet velocity at arbitrary crank angle are determined from thermodynamic analytic method and incylinder states at that crank angle are iteratively determined from the numerical analytic method.

• Geomechanics and Engineering
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• 제18권5호
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• pp.515-525
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• 2019

A karst collapse, as a natural hazard, is totally different to a normal collapse. In recent years, karst collapses have caused substantial economic losses and even threatened human safety. A risk assessment model for karst collapse was developed based on the fuzzy analytic hierarchy process (FAHP) and grey relational analysis (GRA), which is a simple and effective mathematical algorithm. An evaluation index played an important role in the process of completing the risk assessment model. In this study, the proposed model was applied to Jiaobai village in southwest China. First, the main controlling factors were summarized as an evaluation index of the model based on an investigation and statistical analysis of the natural formation law of karst collapse. Second, the FAHP was used to determine the relative weights and GRA was used to calculate the grey relational coefficient among the indices. Finally, the relational sequence of evaluation objects was established by calculating the grey weighted relational degree. According to the maximum relational rule, the greater the relational degree the better the relational degree with the hierarchy set. The results showed that the model accurately simulated the field condition. It is also demonstrated the contribution of various control factors to the process of karst collapse and the degree of collapse in the study area.

• 산업경영시스템학회지
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• 제45권4호
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• pp.118-126
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• 2022

This study attempts a comparison between AHP(Analytic Hierarchy Process) in which the importance weight is structured by individual subjective values and regression model with importance weight based on statistical theory in determining the importance weight of casual model. The casual model is designed by for students' satisfaction with university, and SERVQUAL modeling methodology is applied to derive factors affecting students' satisfaction with university. By comparison of importance weights for regression model and AHP, the following characteristics are observed. 1) the lower the degree of satisfaction of the factor, the higher the importance weight of AHP, 2) the importance weight of AHP has tendency to decrease as the standard deviation(or p-value) increases. degree of decreases. the second sampling is conducted to double-check the above observations. This study empirically checks that the importance weight of AHP has a relationship with the mean and standard deviation(or p-value) of independence variables, but can not reveal how exactly the relationship is. Further research is needed to clarify the relationship with long-term perspective.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.99-112
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• 2014

본 연구는 PL(Private Level)상품 업체 선정을 위한 평가모델을 다룬다. 제안하는 평가모델은 AHP(Analytic Hierarchy Process)를 기반으로 다수의 평가항목에 대한 가중치를 도출한다. 평가항목은 국내 대형마트에서 활용하는 실 업체 선정기준으로, 특히 매출 비중이 높은 식품품목을 대상으로 한다. 식품품목에 대한 54개의 평가항목을 4단계로 계층화 하며, 이를 기반으로 해당 업계 전문가들을 대상으로 한 설문을 수행한다. 설문을 통해 형성한 쌍대비교를 활용하여 평가항목 별 가중치를 추정하며, 이를 실 산업에서 활용 가능한 정량적 대안으로서 제안한다. 마지막으로, 제안하는 평가모델과 기존의 단순합산방식을 비교하는 평가모델 검증을 포함한다. 연구를 통해 PL상품 업체 선정에 중요도가 높은 요소로 HACCP 검증 및 유효성 평가 (0.279281), 운송(원료 입고 및 제품 출하) (0.117706), 법규 준수 중점 관리 (0.066392)를 선별하였다. 제안하는 평가모델은 기존방식으로 우위를 판단하기 힘든 대안들에 대하여 평가 항목의 중요도를 반영함에 따라 업체 선정이 용이한 결과를 제시함을 검증하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.121-124
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• 2000

In IMT-2000 systems, the outer loop dynamically adjusts the target SIR so that adequate performance in terms of the frame error rate(FER) and the true quality measure is achieved. This paper utilizes an analytic model lot outer loop power control(OLPC) adjusting the target SIR in IMT-2000. The analytic model is based on the discrete-time Markov chain as voice traffic SIR. It is described that the model can be used to find the optimum step size in voice traffic for fast fading environments. The optimum step size influences the performance of OLPC： As the step size decreases, the average target SIR increases and average FER decreases.

• 수산경영론집
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• 제38권1호
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• pp.19-45
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• 2007

There have not been many studies which considered both quantitative and qualitative location factors on the issues of site selection problems for a fish farm. This study develops AHP(analytic hierarchy process) model to resolve site selection problem for a fish raising farm by using quantitative and qualitative factors. In order to evaluate the validity of the location factors found in the literature review, the study used advice from fish raising farmers and related academic experts. Four major factors have been selected as economic factors, social factors, natural environmental factors and infrastructures. An AHP structural diagram has developed by considering the factors and potential sites proposed for fish farming. Through the survey on the preference of factors and potential sites, pairwise comparison matrices have been estimated and used to calculated the relative weights of each potential site. The AHP model process shown in the study can be applied to resolve site selection problems for fish raising farmers.