• 한국토양비료학회지
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• 제45권1호
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• pp.25-29
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• 2012

Agriculture activities account for 58% of total anthropogenic emissions of nitrous oxide ($N_2O$) with global warming potential of 298 times as compared to carbon dioxide ($CO_2$) on molecule to molecule basis. Quantifying $N_2O$ from managed soil is essential to develop national inventories of greenhouse gas (GHG) emissions. The objective of the study was to compare $N_2O$ emission from livestock compost applied arable land with that for fertilizer treatment. The study was conducted for two years by cultivating Chinese cabbage (Brassica campestris L.) in Chuncheon, Gangwon-do. Accumulated $N_2O$ emission during cultivation of Chinese cabbage after applying livestock compost was slightly greater than that for chemical fertilizer. Slightly greater $N_2O$ emission factor for livestock compost was observed than that for chemical fertilizer possibly due to lump application of livestock compost before crop cultivation compared with split application of chemical fertilizers and enhanced denitrification activity through increased carbon availability by organic matter in livestock compost.

• 기술사
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• 제15권1호
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• pp.46-50
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• 1982

Following rapid industrial development and urbanization in Korea, there is a need for the Government to implement effective control of pollution and to undertake specific schemes in areas where pollution of the environment is severe. In response to this need, Government of Korea prepare Han River Basin Environmental Master Plan Project for water, air, solid waste to cover environmental protection of the Han River Basin. The Project area is approximately 27,000 sq. Km extending over Seoul, Kyunggi, Kwangwon, Chungbuk Province. The total population of Master Plan Project area is approximately 11.6 million, or one-third of the total population of Korea. There are about 8,000 industries, including those located in 16 industrial complexes, in the project area. The scope of work and terms of reference are the following: (1) A Summary of existing land use and forecasts for changes in land use by the year 2,000. (2) Emission inventories for air, waste water, and solid wastes. (3) Forecasts of future population growth patterns and pollution loadings. (4) Identification of specific projects needs to reduce pollution levels and satisfy the environmental quality standards. (5) A Program of enforcement to include (i) self monitoring, and (ii) governmental inspections and surveillance. (6) A program for quality improvement and quality assurance of environmental measurements. (7) Reports summarizing all data collected analyzed during the study. (8) Conceptual design and feasibility studies, including cost estimates, for needed pollution control projects. (9) A financial plan for future detailed design and construction of public facilities, for financial incentives to industry, and for user charges for industrial use of public treatment of disposal works.

• 한국농공학회논문집
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• 제47권7호
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• pp.3-9
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• 2005

A computer system for crop information was developed using Visual Basic and ArcGIS VBA. The system is operated on ArcGIS 8.3 with Microsoft Access MDB. Landsat +ETM, KOMPSAT-1 EOC, ASTER VNIR and IKONOS panchromatic (Pan) and multi-spectral (MIS) images were included in the system to extract agricultural land use items identifiable at various spatial resolutions of images. Agriculture related data inventories using crop cover information such as texture and average pixel value of each band based on crop cultivation calendar were designed and implemented. Three IKONOS images were loaded in the system to show crop cover characteristics such as rice, pear, grape, red pepper, garlic, and surface water cover of reservoir with field surveys. GIS layers such as DEM (Digital Elevation Model), stream, road, soil, land use and administration boundary were prepared to understand the related characteristics and identify the location easily.

• 대한산업공학회지
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• 제32권4호
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• pp.382-392
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• 2006

Vendor-managed inventory policy(VMIP) is a supply-chain initiative where the supplier is authorized to manage inventories of items at retail locations. In VMIP, the supplier monitors sales and stock information at retail locations and makes decisions of inventory replenishment and transportation simultaneously. VMIP has been known as an effective supply chain strategy that can realize many of benefits obtainable only in a fully integrated supply chain. However, VMIP does not always lead to lower the supply chain cost. It sometimes generates the total supply chain cost higher than the traditional retailer-managed inventory policy (RMIP). In this paper, we perform a comparison study on RMIP and VMIP in the retail supply chain which consists of a single supplier and a number of retailers. We formulate mixed integer programming models for both RMIP and VMIP with vehicle routing problems and perform computational experiments on various test problems. Furthermore, we derive the conditions which guarantee the dominant position for VMIP with respect to total supply chain cost in the simple retail supply chain.

• 농촌계획
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• 제11권4호
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• pp.17-24
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• 2005

The sustainable development of local communities is faced with limitation due to poor infrastructure and lack of cooperation among stake-holders. To overcome such circumstances and thus to ensure balanced development of the local communities, the central government is driving construction of innovative cities mainly through transfer of public institutions to local cities. In this study, to contribute to the development of plans for the future agropolis' associated with the transfer of public institutions, efficient organization mechanisms of the agropolis such as basic structure and spatial allocation was examined through analyses of advanced cases(Sophia Antipolis, St. Hyacinthe Science Part Food Valley, Stoneleigh Park) of foreign countries. The analyses showed that the organization of agropolis were consisted of three main components; 1) agricultural and food industry complex conducting R&D, 2) service facilities(information, trade, consulting and advertisement) supporting agricultural and food industries and rural enterprise center in charge of a variety of events including exhibition, rural experience, education, and contest, 3) silver facilities such as hospital and town providing medical service and residence. Based on the results, inventories of facilities which are necessary in 'the future agropolis' and their spatial allocation were suggested.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.477-480
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• 1996

The main objective of this research is to develop the optimal control method for a Distribution Center - multi Branch inventory distribution system. With the continuous review policy, the distribution center places an order for specific order quantity to an outside supplier, and the order quantity is replenished after a certain lead time. Also, each branch places an order for particular order quantity to the distribution center to satisfy the customer demands, and receives the replenishment after a lead time. When an out of stock condition occurs during an order cycle, a backorder is placed to the upper level to fill the unfilled demands. With these situation, variable demand and variable lead time are used for better industrial practice. Futher, actual lead times with a generic lead time distribution are used in developing the control model. Under the actual lead time model, the customer service measures actually attained for the distribution center and each branch are explained as the effective customer service measures. Thus, throughout the optimal control (using computer search procedures), we can set the desired service levels for the distribution center and each branch to produce the effective service level for each branch which is consistent with the goal level of service for each branch. At the same time, the entire distribution system keeps minimum inventories.

• 산업공학
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• 제10권1호
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• pp.119-134
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• 1997

The management of blood inventory is very important within the medical care system. The efficient management of blood supplies and demands for transfusions is of great economic and social importance to both hospitals and patients. For any blood type, there is a complex interaction among the optimal inventory level, daily demand level, daily supply level, transfusion to crossmatch ratio, crossmatch release period, issuing policy and the age of arriving units that determine the shortage and outdate rate. In this paper, we develop an efficient decision rule for blood inventory management in a hospital blood bank which can support efficient hospital blood inventory management using simulation. The primary use of the efficient decision rule will be to establish minimum cost function which consists of inventory levels, period in inventory, outdate and shortage rate for whole blood and various component inventories for a hospital blood bank or a transfusion service. If the administrator compute the mean daily demand for each blood type, the mean daily supply for each blood type, the length of the crossmatch release period and the average transfusion to crossmatch ratio, then it is possible to apply the efficient decision rule to compute the optimal inventory level, inventory period, outdate and shortage rate. This rule can also be used as a decision support system that allows the blood bank administrator to do sensitivity analysis related to controllable blood inventory parameters.

• Environmental Analysis Health and Toxicology
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• 제19권2호
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• pp.227-233
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• 2004

The main objectives of this study were to identify from literature review the potential sources and to provide a preliminary national emission inventory for the unintentionally produced polychlorinated biphenyls (PCBs) (i.e., by - product PCBs). In Korea, fuel combustion, waste combustion, thermal industrial processes, and transportation were identified as potential sources of by -product PCB s. According to the availability of the emission factors and/or activity data, emission inventory could be assessed only for fuel combustion, waste combustion, steel industry, non-ferrous industry, and non-metallurgical industry. The total national emission of by-product PCBs was estimated to be 1087kg for the year 2000. The preliminary estimation further indicated that the steel manufacturing was the single dominant emission category, contributing 93％ to the total emission. Of the steel manufacturing processes, the contribution of the electric arc furnace was about 80％ of the total emission. Due to high uncertainty associated with both the emission factors and activity statistics, the emission estimates in this study are likely to contain significant errors. However, the results of the present work could serve the first step toward future efforts to establish national source and emission inventories of by-product PCBs.

• 한국경영과학회지
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• 제18권3호
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• pp.151-157
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• 1993

In this paper, we investigate the effects of yield randomness for lot-sizing in a multi-stage production system. The practical importance of incorporating yield randomness into production models has been emphasized by many researchers. Yield randomness, especially in semiconductor manufacturing, poses a mojor challenge for production planning and control. The task becomes even more difficult if the demand for final product is uncertain. An attempt to meet the demand with a higher level of confidence forces one to release more input in the fabrication line. This leads to excessive work-in-process (WIP) inventories which cause jobs to spend unpredictably longer time waiting for the machines. The result is that it is more difficult to meet demand with exceptionally long cycle time and puts further pressure to increase the safety stocks. Due to this spiral effect, it is common to find that the capital tied in inventory is the msot significant factor undermining profitability. We propose a policy to determine the quantity to be processed at each stage of a multi-stage production system in which the yield at each stage may be random and may need rework.

• 경영과학
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• 제31권2호
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• pp.33-48
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• 2014

It is important to maintain on operational availability of aircraft during wartime. The KF-16 fighter, the backbone of the ROKAF (Republic Of Korea Air Force), has a single engine. Therefore, the engine has a critical influence on operational availability. The purpose of this study is to estimate optimal levels of spare part inventories concerning both engines and modules. That is provided by linear programming methods utilizing a developed meta-model. For drawing out the meta-model, we develop a simulation model which can consider wartime demands. In the previous study, $2^k$ factorial design method is used to check the influence of each independent variable. That method requires relatively many scenarios because every extreme value combination of independent variables should be checked. However, this study adopts NOLH (Nearly Orthogonal Latin Hypercube) as an experimental design. By adopting NOLH, this study increases not only efficiency but also accuracy. That is proven by comparing the validity of the developed meta-model on both experimental designs. This study also utilizes the OptQuest simulation tool in ARENA to derive the optimal level of spare stocks. By comparing the result of OptQuest to that of the developed meta-model, the validity of this study is secured.