• Structural Engineering and Mechanics
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• v.52 no.5
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• pp.919-935
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• 2014

In this study, the control of the shape of pre-stressed cable structures and the effective control element were examined. The process of deriving the displacement control equations using the force method was explained, and the concurrent control scheme (CCS) and the sequence control scheme (SCS) were proposed. To explain the control scheme process, the quadrilateral cable net model was adopted and classified into a regular model and an irregular model for the analysis of the control results. In the control analysis of the regular model, the CCS and SCS analysis results proved reliable. For the SCS, the errors occur in the control stage and varied according to the control sequence. In the control analysis of the irregular model, the CCS analysis result also proved relatively reliable, and the SCS analysis result with the correction of errors in each stage was found nearly consistent with the target shape after the control. Finally, to investigate an effective control element, the Geiger cable dome was adopted. A set of non-redundant elements was evaluated in the reduced row echelon form of a coefficient matrix of control equations. Important elements for shape control were also evaluated using overlapping elements in the element sets, which were selected based on cable adjustments.

• Korean System Dynamics Review
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• v.9 no.2
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• pp.5-25
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• 2008

This paper analysed the impact of return policy as a coordination mechanism for decentralized supply chain with one capacitated supplier and two competing retailers under random demand distribution. In this study, Shortage gaming also considered to reflect a competing environment of two retailers. System dynamics approach was used to model the baseline two echelon supply chain and return policy on it. Given each of 4 experiment settings being used for 100 simulations with different random seeds, 400 random samples were used in a t-test. The result show that return policy significantly enhance the supply chain profits and fillrates. The analysis suggest that the supply chain performance can be build up by implementing a return policy even though under consideration of a capacitated supplier and competing retailers.

• Journal of Biosystems Engineering
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• v.35 no.2
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• pp.138-145
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• 2010

An on-line algorithm that discriminates brown rice kernels on their echelon feeder using color image processing is presented for quality inspection. A rapid color image segmentation algorithm based on Bayesian clustering method was developed by means of the look-up table which was made from the significant clusters selected by experts. A robust estimation method was presented to improve the stability of color clusters. Discriminant analysis of color distributions was employed to distinguish nine types of brown rice kernels. Discrimination accuracies of the on-line discrimination algorithm were ranged from 72% to 85% for the sound, cracked, green-transparent and green-opaque, greater than 93% for colored, red, and unhulled, about 92% for white-opaque and 67% for chalky, respectively.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.742-749
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• 2002

This paper deals with a continuous-review two-echelon inventory model with one-for-one replenishment and Poisson demand where transshipments among retailers are allowed. Two classes of inventory systems are considered by the number of distribution centers(DCs) which provide each retailor with inventory items. 1:N class inventory system and M:N class inventory system respectively. Two-phase model is constructed to find out the optimal inventory positions which minimize supply chain costs. Approximations for customer service levels of the system are evaluated in the first phase, and the optimal inventory positions are found subject to the constraints for service level in the second phase. Simulation tests are performed to assure the effectiveness of the proposed model. The effect of transshipment is evaluated.

• 한국데이터정보과학회:학술대회논문집
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• 2004.04a
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• pp.183-194
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• 2004

본 연구에서는 공간 검색 통계량(spatial scan statistics)과 에셜론 해석법을 이용한 범주형 자료분석을 다룬다. 이를 위해 우선, 에셜론 덴드로그램을 이용하여 주어진 분활표의 계층적 구조(hierarchical structure)를 결정하고서 이로부터 핫스팟(hotspot)의 후보를 검출한다. 다음으로 우도비(likelihood ratio)를 기초로 유의하게 높거나 낮게 나타나는 지역에 대한 공간 검색 통계량을 산출한다. 마지막으로, 이 통계량을 바탕으로 핫스팟을 검출한다.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.525-532
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• 2021

The study investigates the mediating effect of Korean firms' corporate social responsibility (CSR) in the relationship between Korean executives' religiosity, their individual social responsibility (ISR), and corporate financial performance (CFP). As executives lead the firms' strategies and policies, their religiosity or ISR may have a significant influence in attaining the firm's CSR and influencing CFP. The upper echelon theory, agency theory, and stakeholder theory are used to explain the link between individual-level drivers of CSR, a firm's CSR, and CFP. The upper echelon theory, agency theory, and stakeholder theory are integrated into the conceptual model, which explains the relationships between proposed constructs in this study. This study employs survey data of 421 Korean companies. The confirmatory factor analysis (CFA) technique was used to test the proposed hypotheses. The main result shows that Korean executives' religiosity and their ISR positively influence CFP when mediated by CSR. The findings of this study suggest that Korean executives' personal values such as their religiosity and ISR can impact the firm's CSR activities or financial performance. Overall, this paper responds to the recent calls in the CSR literature to examine the individual-level drivers from non-western contexts by shedding more light on the Korean context.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.650-658
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• 2020

The research of the AI-based command decision support system was insufficient both quantitatively and qualitatively. In particular, in Korea, there was no research on concrete concept design at the current concept research level. This paper proposed the conceptual design of a tactical echelon command decision support system based on artificial intelligence(AI) according to the current army's doctrine of the operation process. The suggested conceptual design clarified the problem and proposed an appropriate process for design, and applied the function analysis method among rational techniques that enable conceptual design systematically.

• Journal of Mechanical Science and Technology
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• v.19 no.8
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• pp.1554-1567
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• 2005

When multiple robotics systems with several sub-chains grasp a common object, the inherent force redundancy provides a chance of utilizing internal loading. Analysis of grasping space based internal loading is proposed in this work since this method facilitates understanding the physical meaning of internal loadings in some applications, as compared to usual operational space based approach. Investigation of the internal loading for a triple manipulator has been few as ,compared to a dual manipulator. In this paper, types of the internal loading for dual and triple manipulator systems are investigated by using the reduced row echelon method to analyze the null space of those systems. No internal loading condition is derived and several load distribution schemes are compared through simulation. Furthermore, it is shown that the proposed scheme based on grasping space is applicable to analysis of special cases such as three-fingered and three-legged robots having a point contact with the grasped object or ground.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.73-82
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• 2006

Supply chain management (SCM) has been regarded as one of the most critical issues in the current business environment. Moreover, supply chain partnerships between suppliers and buyers in SCM have had a significant impact on supply chain performance. In this paper, we conduct a quantitative analysis for supplier-buyer's profit sharing and pricing policies based on supply chain partnerships. For this purpose, we assume that a two echelon supply chain with a single supplier and a single buyer is given and the buyer faces deterministic demand which is not only a function of buyer's selling price, but also strictly decreasing, concave, and twice differentiable function. Then we will prove the following. Firstly, without supply chain partnerships, there exist supplier and buyer's selling prices per unit such that their total profits are maximized, under the assumption that buyer's order quantity is exactly equal to the demand buyer faced. Secondly, buyer's selling price per unit which maximizes supply chain's total profit with supply chain partnerships is lower than buyer's selling price per unit which maximizes buyer's total profit without supply chain partnerships. Thirdly, given supplier's selling price per unit. buyer's total profit without supply chain part nerships is greater than that with supply chain partnerships, whereas the opposite case happens for supplier's total profit. Finally, there exists supplier's selling price per unit which makes the maximum total profits for both supplier and buyer with supply chain partnerships greater than those obtained for any given supplier's selling price per unit without supply chain partnerships.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.145-150
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• 2006

In terms of that modem equipment become expensive, sophisticated and huge, the cost of developing the equipment is much considered in ILS. Therefore, the model of the level of repair analysis about equipment which have the multi-echelon and multi-indenture are purposed to derive optimal repair policy which mostly satisfy the availability by using the Mixed Integer Programming within the minimum cost.