• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.91-103
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• 2006

Given a bill of materials (BOM) tree T labeled by the breadth first search (BFS) order from node 0 to node n and a general network ${\Im}=(V,A)$, where V={1,2,...,m} is the set of production facilities and A is the set of arcs representing transportation links between any of two facilities, we assume that each node of T stands for not only a component. but also a production stage which is a possible stocking point and operates under a periodic review base-stock policy, We also assume that the random demand which can be achieved by a suitable service level only occurs at the root node 0 of T and has a normal distribution $N({\mu},{\sigma}^2)$. Then our integrated model of facility location problems and safety stock optimization problem (FLP&SSOP) is to identify both the facility locations at which partitioned subtrees of T are produced and the optimal assignment of safety stocks so that the sum of production cost, inventory holding cost, and transportation cost is minimized while meeting the pre-specified service level for the final product. In this paper, we first formulate (FLP&SSOP) as a nonlinear integer programming model and show that it can be reformulated as a 0-1 linear integer programming model with an exponential number of decision variables. We then show that the linear programming relaxation of the reformulated model has an integrality property which guarantees that it can be optimally solved by a column generation method.

• The Journal of shipping and logistics
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• v.27 no.1
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• pp.79-98
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• 2011

The volume of the world's container transportation has been increasing. To serve this transportation need, the size of the container carrier is getting larger. The global ports are required to deepen the waterways as well as to prepare infrastructure to serve these super-size container carriers. However, few ports around the world could meet the requirements. To solve these difficulties, the concept of the Mobile Harbor has been developed. An onboard Automatic Storage and Retrieval System(AS/RS) has been proposed for the B1 type Mobile Harbor to maximize the container throughput within the limited space of the Mobile Harbor. A scenario of operations and freight movements of the B1 type Mobile Harbor is prepared and the storage size of the B1 type Mobile Harbor through the computer simulation is estimated. The size of the Mobile Harbor and the size of the AS/RS has also been estimated. The optimized size of the Mobile Harbor could be proposed.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.205-210
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• 2008

Life cycle assessment(LCA) is acknowledged as a valuable tool to quantify the environment impact of agricultural practice as well as final product(biodiesel) considering whole life cycle of the target product. As a preliminary research of LCA study for rapeseed(Brassica napus L.) biodiesel, the methodological issues which have to be regarded with high priority were dealt with. No life cycle inventory(LCI) based on local data are currently available for LCA of rapeseed cultivation, crushing, and conversion to rapeseed methyl ester(RME) in Korea. In this paper, the life cycle of rapeseed and methodological factors which have to be measured for building LCI of each process are provided and discussed, which are including seed, fertilizer, energy use in rapeseed cultivation environment; and crushing, RME conversion, and transportation in biodiesel production.

• Journal of the Korean Geographical Society
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• v.36 no.3
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• pp.258-277
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• 2001

Agricultural Co-operation chain stores were highly the utility of distribution rationalization for commercial distribution by informatisation and by multi-polarizied of large physical distribution center of Inventory intensive type consisted of intensive physical distribution. and transportation of commodities from physical distribution center have act by outsourcing. Therefore, the methods of distribution of commodities of life and agricultural products are distinguished from route distribution and regular time collective distribution. the method of distribution is formated the distribution field b\ulcorner characteristic of commodity. On the other hand, spatial characteristics by sales activities of commodities was clarified by types of stole commodity according to level of paddy agriculture development and level of service industrial employment. But manufactured foodstuffs and miscellaneous goods. that is commodities of life clarified the fact selling that is not influenced by regional type.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3304-3310
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• 2010

This study solves the decision making problems for TFT-LCD manufacturing supply chain with demand and price uncertainties by establishing robust production and distribution strategies. In order to control the decisions regarding production graded by quality, inventory level and distribution, this study develop scenario model based stochastic mixed integer linear programs (SMILPs) that consider demand and price uncertainties as well as realistic constraints such as capacities etc. The performance of the solution obtained from the SMILPs using robust algorithms will be evaluated through various scenarios.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.524-531
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• 2006

Environmental problem is one of important global issues. Transportations are main pollutant emission sources. Although railroad is stilt an environmental-friendly transportation, its environmental impact has been increased continuously. Especially, because a large amount of environmental impact is released from vehicles and facilities, it is necessary to assess and to reduce their environmental impact. Life cycle assessment (LCA) is a representative method which can evaluate environment impact through the whole life cycle of a product or a process. In this study, the environmental impact of seat in the electric motor unit (EMU) was analyzed quantitatively with its material using lift cycle assessment (LCA). As a result, the characteristics of environmental impact were investigated differently with the material of seat. Among ten impact categories, the seat with aluminum and FRP showed the highest ozone depletion (OD). On the other hand, in the seat with stainless steel and plastic, fresh water aquatic ecotoxicity (FAET) and marine water aquatic ecotoxicity (MAET) were high relatively. Therefore, the parts of EMU must be selected considering the characteristics of environmental impact in future.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1244-1249
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• 2007

Pursuing sustainable development throughout society and industry and the field of environmental policy, each international organization or nation has performed international standardization projects on environmental management activities for their system as well as environmental assessment for a product such as life cycle assessment (LCA) and life cycle inventory database (LCI DB), and the environmental aspects have been increasingly demanded as crucial evaluation specifications. Moreover, the conventional environmental policy, which represents the direct-control, has been more dependent on the market forces and product itself after the Climate Change Convention., and the Integrated Product Policy (IPP, EU) is applied vigorously to strengthen global competitiveness of a product and to achieve the effect of environmental improvement for it. According to change of the international railway market, the value of Eco-Design has been increasingly important in developed countries including EU. Thus, each country is establishing its own guidelines, software and database for each product, and developing new policies through Eco-Design with practical results in marketing. To react this and develop Korean railway as an environment-friendly industry with priority to other transportation system as well as maintain high place in technology, the direction of RACE software development of main function is introduced, which is exclusively used for EMU to assess both environmental and economic aspects with LCA and eco-efficiency (EE).

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.751-771
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• 2011

Biogenic Volatile Organic Compound (BVOC) emissions are estimated with BEIS3.12 (Biogenic Emissions Inventory System version 3.12) over the Seoul Metropolitan Area (SMA) and then used in CMAQ (Community Multiscale Air Quality) simulations for two high ozone episodes in 2004 and 2007 June. The first- and second-order sensitivity coefficients of ozone to BVOC emissions are estimated with High-order Decoupled Direct Method (HDDM) simulation in order to estimate the influence of BVOC emissions on ozone using the Zero-Out Contribution (ZOC) approach. ZOC analysis shows that relative contribution of BVOC emissions on daily maximum 1-hr ozone is as high as 30% for high ozone days above 100 ppb. However simulated isoprene concentrations were over-estimated by a factor of 2 when compared to the observations at the PAMS (Photochemical Air Monitoring Station) for the 2007 episode. When assumed that actual BVOC emissions are 50% less than estimated, the ZOC of BVOC emissions on daily maximum ozone drops by more than 10 ppb for the episode. The result indicates that uncertainty in BVOC emissions may have significant impact on high ozone prediction in the SMA.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.1
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• pp.45-52
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• 2015

PURPOSE: The purpose of this study was to observe the effect of pain and function according to the high and low manual passive coping strategies after whiplash injury. METHODS: The study was tested with 30 patients with neck pain. Coping was measured at after 10 days using the Pain Management Inventory. Group was divided into high passive(experimental) and low passive(control) group. All patients were equally treated with the ordinary therapy. Patients attended physical therapy for 3 times a week, for 6 weeks. Visual analogue scale (VAS) for pain, Pain Disability Index (PDI), neck disability index (NDI), were recorded both before and after the intervention. RESULTS: Each coping strategy group were evaluated after 6 weeks. VAS has been significantly reduced in both groups (p <.05). PDI and NDI was significantly decreased after the experiment before. In the experimental group (p <.001), the control group showed no significant difference. In the comparison between groups VAS was significantly reduced compared with the control group (p <.05), PDI and NDI was significantly reduced compared with the control group (p <.001). CONCLUSION: Low passive coping strategy predicts neck pain and disability recovery. It may be beneficial to assess and improve coping strategy early in whiplash injury.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.60-67
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• 2014

This paper considers an inbound ordering and outbound dispatching problem for multi-products and multi-vehicles in a third-party distribution center. The demands are dynamic over a discrete and finite time horizon, and replenishing orders are shipped in various transportation modes and the freight cost is proportional to the number of vehicles used. Any mixture of products is loaded onto any type of vehicles. The objective of the study is to simultaneously determine the inbound lot-sizes, the outbound dispatching sizes, and the types and numbers of vehicles used to minimize total costs, which consist of inventory holding cost and freight cost. Delivery time window is one of the general dispatching policies between a third-party distribution center and customers in practice. In the policy, each demand of product for a customer must be delivered within the time window without penalty cost. We derive mixed integer programming models for the dispatching policy with delivery time windows and on-time delivery dispatching policy, respectively and analyze the effect on a dispatching policy with delivery time windows by comparing with on-time delivery dispatching policy using various computational experiments.