• Communications for Statistical Applications and Methods
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• v.7 no.2
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• pp.513-523
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• 2000

The X-12-ARIMA program was utilized on the analysis of the time series trend on 76 Korean industrial activities data in order to ensure that the trading day effect adjustment as well as the seasonal effect adjustment is needed to extract the fundamental trend-cycle factors from various economic time series data. The trading day effect is strongly correlated with the activity of production and shipping but not with the activity of inventory. Furthermore, the industrial activities were classified with respect to the sensitivity on the tranding day effect.

• Management Science and Financial Engineering
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• v.13 no.2
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• pp.117-139
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• 2007

This paper contributes by incorporating works addressing supply chain coordination and investing in setup reduction program. Consider a two-echelon, EOQ-like inventory system consisting of a supplier and a buyer. We assume that both the supplier and the buyer can invest in setup cost reduction programs in order to benefit from small order sizes. However, the costs of investing in setup cost reduction programs are different for the two parties, leading to mismatches in individually optimal setup costs and order cycle times. We propose a supply chain coordination contract that makes use of quantity discount as an incentive transfer scheme for supply chain coordination.

• Journal of the Korea Safety Management & Science
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• v.12 no.1
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• pp.71-81
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• 2010

Today's fierce competition and global economic recession make most of manufacturing companies in the world difficult to gain a profit. In order to survive such a environment and increase competitiveness, manufacturing companies have to continuously eliminate their wasteful factors through an efficient process analysis, improve quality of products, increase the flexibility of manufacturing processes. In this paper, we consider a case study for the Shanghai New Auto which is a subcontractor of MOBIS in China, to improve productivity by using therblig method, one of the motion analysis, to minimize the work-in-process inventories and to shorten the manufacturing cycle times. We also try to relocate the facility layout to increase the efficiency and flexibility of manufacturing processes.

• Korean Journal of Computational Design and Engineering
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• v.17 no.1
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• pp.1-6
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• 2012

The End Coupling is main component of the aluminum hot roll process. The End Coupling is used for transmission of rotational power with heavy-duty load. Fracture of the End Coupling cause serious economic losses because an End Coupling is a very expensive component and it takes a long time to repair it. Therefore, preventing the destruction of the End Coupling is essential for ensuring a long mechanical life cycle. In this paper, the parametric study on the End Coupling was performed in order to minimize maximum stress under operation loads. To verify the interference of spindle assembly with modified End Coupling, kinematics simulation was performed by applying the various combination type and dynamic boundary condition of the spindle assembly. The interference of optimized model was not occurred during combination process and driving process. As a result of an optimum design for life extension on End Coupling, the maximum stress of modified End Coupling was lower than that of the initial model by 26%.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.299-308
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• 2009

In this paper, we have developed an evaluation model of technology green index(TGI) which includes 3 evaluation factors and 13 indicators. Furthermore, as presenting the degree of relative importance among evaluation factors and indicators for all R&D evaluation stages and all green technology areas, and applying the proposed model to 5 defense projects, we have found applicability of the model to evaluation of defense R&D projects. The results of evaluation using this model can be used to monitor the performance of project life cycle and develop R&D investment strategy of green technology using portfolio analysis.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.750-755
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• 2014

Product shortage which causes backordering and/or lost sales cost is very popular in chemical industries, especially in commodity polymer business. This study deals with backordering cost in the supply chain optimization model under the framework of process-inventory network. Classical economic order quantity model with backordering cost suggested optimal time delay and lot size of the final product delivery. Backordering can be compensated by advancing production/transportation of it or purchasing substitute product from third party as well as product delivery delay in supply chain network. Optimal solutions considering all means to recover shortage are more complicated than the classical one. We found three different solutions depending on parametric range and variable bounds. Optimal capacity of production/transportation processes associated with the product in backordering can be different from that when the product is not in backordering. The product shipping cycle time computed in this study was smaller than that optimized by the classical EOQ model.

• Journal of the Ergonomics Society of Korea
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• v.9 no.2
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• pp.11-20
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• 1990

Recorded injury identified the role of falls in producing injury througout all segments of the nation. The Economic and social costs arising from falls has been established in numerous sources, both nationally and from the intermational literature. Recorded injury also indicated the potential features of falls, the need for a basic understanding of the energy exchange mechanism involved and the subsequent rehabilitation processes required. It appears unlikely that any other major cause of injury has an etiology so little researched and consequently, so little understood, which in turn has prevented the development of an intervention strategy or a scientically based control technology of falls. This paper will emphasize how the postural changes of foot are related to slip/fall severity in different environmental conditions. Lidewise, we will examine the whole slip/fall cycle through the biomechanical parameters involved in a range of walking speed and floor slipperiness

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.127-128
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• 2010

As P-new-city is planned and constructed, district eating utilizing an existing near-by power plant's waste heat is considered as an economic and environment friendly way of providing heating to the new city. Many pipeline diameters and pumping station location and capacity were assumed, investigated and optimized, to satisfy the customers' heat demand considering common district heating pipe-network design and construction practice, and also and construction, pumping station land price and construction and the pumping energy cost during lifetime of DH systems.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.4
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• pp.1-8
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• 2003

It is well known that design cost is only about 5% of final product cost but over 70% of it is determined during design stage. Earlier in the product design and development cycle the design changes occur, more economic they become. Therefore, it is recommended that the manufacturing time and cost of product are considered in steps involved in designing and manufacturing a product as early as possible. In this study, it is proposed a possible way that cm be available for estimating manufacturing time of parts, which are manufactured by conventional material removal processes (e.g. turning, milling and drilling). For it to be useful in the early design stage, the minimum number of informations on dimension shape, and design features of part will be used in this method.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.537-541
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• 2003

The synchronization of production-delivery artivities is one of crucial factors to get competitive collaboration benefits between the manufacturer and the retailor(s). There were several researches to study on He optimal delivery policy to minimize the total cost of integrated system of both manufacturer and retailor(s). In this research, we investigate the joint optimal shipment policy in case that a manufacturer produces multiple products sharing a single production facility in the manufacturer side and retailor(s) deploys JIT delivery pattern with equal-size shipment policy. We formulate this problem as a form of 'Common Cycle Approach' in classical ELSP (Economic Lot Scheduling Problem) and provide simple optimal solution procedure.