• 지식경영연구
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• 제16권1호
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• pp.71-93
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• 2015

With the rapid growth of the internet, electronic commerce has become accepted as one of the major purchasing channels for consumers. As more and more consumers search for and purchase products through the internet, intra-industry competition of electronic commerce has become fierce. Therefore, electronic commerce service providers pay attention to factors that prevent existing customers from leaving there services in the service failure situation. In this regard, electronic commerce service providers should make service recovery efforts for consumer recovery satisfaction after service failure. In this study, we suggest that procedural justice, interactional justice, distributive justice and authenticity have positive impacts on recovery satisfaction. In addition, we also propose that involvement plays moderating roles in the relationships between procedural justice, interactional justice, distributive justice, authenticity and recovery satisfaction. We collected empirical data for this study over a period of two weeks from subjects who had service failure recovery experiences through electronic commerce. A total of 224 complete and valid responses were obtained. We carried out data analysis using a two-step methodology with SPSS 20.0 and SmartPLS 2.0. The first step in the data analysis was to establish the internal consistency, convergent validity, discriminant validity of the constructs. In the second step, we examined the structural model. The empirical results support the proposed model and partly identify the moderating effect of involvement differences. The moderate effect results show that procedural justice, distributive justice and authenticity have different impacts on recovery satisfaction in two groups. Cognitive factor such as the procedural justice and distributive justice have stronger impacts on recovery satisfaction in the high-involvement goods than in the low-involvement goods, while emotional factor such as authenticity has a stronger impact on recovery satisfaction in the low-involvement goods than in the high-involvement goods. We expect that this result will provide researchers and managers who are interested in electronic commerce service failure recovery with useful theoretical and practical implications.

• 한국추진공학회지
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• 제4권4호
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• pp.9-17
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• 2000

준안정상인 $\beta$형 HNIW의 용해와 안정상인 $\varepsilon$형 HNIW의 성장 특성을 고려한 모델식을 물질수지와 한께 계산하는 방법으로 결정성장 속도와 용해 속도를 계산하였다. 제시된 모델은 용액을 매체로 하여 진행되는 $\beta$$\longrightarrow$$\varepsilon$전이 현상에 대한 속도론적 데이터를 모사 하는데 유용하였다. 2 단 모델을 이용한 유효 인수로부터, 격정성장 과정에서 표면 축적 단계의 영향은 작으며, 확산 의존성은 ethyl acetate와 chloroform의 혼합 용매 중 chloroform의 함량이 증가함에 따라 감소함을 보였다. 이들 속도론 적 계수들을 이용한 수치모사를 통하여 $\varepsilon$-HNIW의 입자 크기를 예측하는 것이 가능하였다.

• Environmental Engineering Research
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• 제21권4호
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• pp.365-372
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• 2016

The effects of hydrodynamics and alum dose on particle growth were investigated by monitoring particle counts in a rapid mixing process. Experiments were performed to measure the particle growth and breakup under various conditions. The rapid mixing scheme consisted of the following operating parameters: Velocity gradient (G) ($200-300s^{-1}$), alum dose (10-50 mg/L) and mixing time (30-180 s). The Poisson regression model was applied to assess the effects of the doses and velocity gradient with mixing time. The mechanism for the growth and breakup of particles was elucidated. An increase in alum dose was found to accelerate the particle count reduction. The particle count at a G value of $200s^{-1}$ decreased more rapidly than those at $300s^{-1}$. The growth and breakup of larger particles were more clearly observed at higher alum doses. Variations of particles due to aggregation and breakup of micro-flocs in rapid mixing step were interactively affected by G, mixing time and alum dose. Micro-flocculation played an important role in a rapid mixing process.

• 대한기계학회논문집
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• 제17권7호
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• pp.1700-1709
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• 1993

The stepped specimen which is subjected to step loading is modeled to study the initiation and growth of adiabatic shear band using explicit time integration finite element method. Three different clearance sizes are tested. The material model for the stepped specimen includes effects of strain hardening, strain rate hardening and thermal softening. It is found that the material inside the fully grown adiabatic shear band experiences three phase of deformation, (1) homogeneous deformation phase, (2) initiation/incubation phase, and (3) fast growth phase. The second phase of deformation is initiated after sudden shear stress drop which occurs at the same time regardless of the clearance size. The incubation time prior to fast growth phase increases, as the clearance size of the stepped specimen increases. Whereas, after incubation period, the growth rate of the adiabatic shear band decreases, as the clearance size decreases. It is also found that two adiabatic shear band may develop instead of one for the smaller clearance size.

• 유통과학연구
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• 제14권11호
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• pp.83-90
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• 2016

Purpose - During the last two years, convenient stores (CS) are emerging as one of the most fast-growing retail trades in Korea. The goal of this work is to forecast and to analyze sales at CS using ARIMA-Intervention model (IM) and exponential smoothing method (ESM), together with sales at supermarkets in South Korea. Considering that two retail trades above are homogeneous and comparable in size and purchasing items on off-line distribution channel, individual behavior and characteristic can be detected and also relative superiority of future growth can be forecasted. In particular, the rapid growth of sales at CS is regarded as an everlasting external event, or step intervention, so that IM with season variation can be examined. At the same time, Winters ESM can be investigated as an alternative to seasonal ARIMA-IM, on the assumption that the underlying series shows exponentially decreasing weights over time. In case of sales at supermarkets, the marked intervention could not be found over the underlying periods, so that only Winters ESM is considered. Research Design, Data, and Methodology - The dataset of this research is obtained from Korean Statistical Information Service (1/2010~7/2016) and Survey of Service Trend of Korea Statistics Administration. This work is exploited time series analyses such as IM, ESM and model-fitting statistics by using TSPLOT, TSMODEL, EXSMOOTH, ARIMA and MODELFIT procedures in SPSS 23.0. Results - By applying seasonal ARIMA-Intervention model to sales at CS, the steep and persisting increase can be expected over the next one year. On the other hand, we expect the rate of sales growth of supermarkets to be lagging and tied up constantly in the next 2016 year. Conclusions - Based on 2017 one-year sales forecasts for CS and supermarkets, we can yield the useful information for the development of CS and also for all retail trades. Future study is needed to analyze sales of popular items individually such as tobacco, banana milk, soju and so on and to get segmented results. Furthermore, we can expand sales forecasts to other retail trades such as department stores, hypermarkets, non-store retailing, so that comprehensive diagnostics can be delivered in the future.

• 한국멀티미디어학회논문지
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• 제16권5호
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• pp.637-646
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• 2013

본 연구는 다수의 나무로 구성된 실외 지형에 적합하고 다양하고 자연스러운 나무를 모델링하기 위하여 새로운 성장 규칙(약수 함수의 합성 곱 기반)의 모델링 방법을 제안한다. 기본적으로 나무를 구성하는 가지와 잎의 효율적 관리와 자연스러운 가지 증식을 위하여 기존의 성장 볼륨기반 알고리즘을 활용한다. 이 논문의 주요 특징은 각 성장 단계에서 가지와 잎의 성장과 운명을 자연스럽게 표현하는 약수 함수 합성 곱 이론을 도입하는 것이다. 이를 기반으로 일반화된 생성 함수를 갖는 여러 약수 함수와 성장 규칙의 변형을 통해 사용자의 제어를 최소화하여 다양한 나무를 모델링하는 방법을 제안한다. 이 모델링 방법은 가지와 잎을 동시에 고려하는 특징이 있으며, 다수의 나무들로 구성된 실외 지형 구축에 보다 효과적이라는 이점이 있다. 제안한 방법을 통해 자연스럽고 다양한 나무 모델 생성과 이를 활용하여 넓은 자연 지형 구축 가능성과 다수의 나무를 구성하는 과정에서의 효율성을 실험을 통해 증명한다.

• 벤처창업연구
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• 제5권4호
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• pp.95-111
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• 2010

현대의 기업 경쟁력은 경쟁력 있는 신제품 개발이 필수적이다. 기업이 지속적인 성장을 하기 위해서는 신제품을 개발해야 한다. 본 논문에서는 제품 설계의 고객의 목소리를 충분히 반영한 제품을 제안하였다. 1차 설계에서 Kano의 매력 품질특성을 반영하여 설계하였고, 2차 설계에선 Kano 품질 특성에서 일원적 품질특성이 Timko가 제안한 고객만족지수 방법을 통하여 찾아진 고객 요구를 만족하는가를 분석하였다. 또한 Kano의 매력품질을 찾는 기법과 Timko의 고객만족지수를 찾는 기법을 신제품 개발에 적용하면 매우 효과적으로 문제를 해결할 수 있다.

• Structural Engineering and Mechanics
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• 제19권6호
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• pp.639-652
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• 2005

In this paper, a full-scale K-joint specimen was tested to failure under cyclic combined axial and in-plane bending loads. In the fatigue test, the crack developments were monitored step by step using the alternating current potential drop (ACPD) technique. Using Paris' law, stress intensity factor, which is a fracture parameter to be frequently used by many designers to predict the integrity and residual life of tubular joints, can be obtained from experimental test results of the crack growth rate. Furthermore, a scheme of automatic mesh generation for a cracked K-joint is introduced, and numerical analysis of stress intensity factor for the K-joint specimen has then been carried out. In the finite element analysis, J-integral method is used to estimate the stress intensity factors along the crack front. The numerical stress intensity factor results have been validated through comparing them with the experimental results. The comparison shows that the proposed numerical model can produce reasonably accurate stress intensity factor values. The effects of different crack shapes on the stress intensity factors have also been investigated, and it has been found that semi-ellipse is suitable and accurate to be adopted in numerical analysis for the stress intensity factor. Therefore, the proposed model in this paper is reliable to be used for estimating the stress intensity factor values of cracked tubular K-joints for design purposes.

• Structural Engineering and Mechanics
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• 제73권4호
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• pp.455-462
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• 2020

The hybrid method using the extended finite element method (XFEM) and the forward Euler approach is widely employed to predict the fatigue life of plate structures. Due to the accuracy of the forward Euler approach is determined by a small step size, the performance of fatigue life prediction of the hybrid method is not agreeable. Instead the forward Euler approach, a prediction method using midpoint method and support vector regression (SVR) is presented to evaluate the stress intensity factors (SIFs) and the fatigue life. Firstly, the XFEM is employed to calculate the SIFs with given crack sizes. Then use the history of SIFs as a function of either number of fatigue life cycles or crack sizes within the current cycle to build a prediction model. Finally, according to the prediction model predict the SIFs at different crack sizes or different cycles. Three numerical cases composed by a homogeneous plate with edge crack, a composite plate with edge crack and center crack are introduced to verify the performance of the proposed method. The results show that the proposed method enables large step sizes without sacrificing accuracy. The method is expected to predict the fatigue life of complex structures.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1327-1338
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• 2013

The humanized anti-hepatocyte growth factor (HGF) monoclonal antibody (mAb) YYB-101 is a promising therapeutic candidate for treating various cancers. In this study, we developed a bioprocess for large-scale production of YYB-101 and evaluated its therapeutic potential for tumor treatment using a xenograft mouse model. By screening diverse chemically defined basal media formulations and by assessing the effects of various feed supplements and feeding schedules on cell growth and antibody production, we established an optimal medium and feeding method to produce 757 mg/l of YYB-101 in flask cultures, representing a 7.5-fold increase in titer compared with that obtained under non-optimized conditions. The optimal dissolved oxygen concentration for antibody production was 70% $pO_2$. A pH shift from 7.2 to 7.0, rather than controlled pH of either 7.0 or 7.2, resulted in productivity improvement in 5 L and 200 L bioreactors, yielding 737 and 830 mg/ml of YYB-101, respectively. The YYB-101 mAb highly purified by affinity chromatography using a Protein A column and two-step ion exchange chromatography effectively neutralized HGF in a cell-based assay and showed potent tumor suppression activity in a mouse xenograft model established with human glioblastoma cells.