• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.37-44
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• 2018

Purpose: The objective of this study was to investigate the high-efficiency anaerobic digestion of organic wastes with high fat content. Specifically, the analysis focused on biogas production performance with a focus on carbon number and the double bond count of the long-chain fatty acids (LCFAs), which are hydrolysis products of triglycerides. Methods: Experiments were performed under mesophilic anaerobic conditions with a feed-to-microorganism ratio (F/M) of 1.0. Biogas production performance was analyzed through biogas production patterns, lag-phase, and the time required for 90% biogas production (T90). Results: Biogas production increased when the content of unsaturated LCFAs (containing relatively large numbers of carbon atoms) increased. In substrate containing LCFAs with four or more double bonds, although the initial lag-phase in biogas production was shortened, development of a three-step lag-phase resulted in decreased biogas production. These results suggest that high rates of anaerobic digestion are possible when the LCFAs have high unsaturated fatty acid content with three or fewer double bonds. Conclusions: When various types of LCFAs are digested anaerobically, biogas production performance can be improved if the unsaturated fatty acid content and number of double bonds are optimized for maximum production.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.173-181
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• 2016

This study designed a model of the efficient production schemes and raw materials transportation optimization of current South Korean's simple and monolithic distribution system of wood to build a SCM (supply chain management) as a basic level to establish a distribution of future by pellet production of raw materials costs and reduce transport costs, and specifically to forest of pallet to contribute to revitalizing the market. The result of each transportation costs after building the best transportation network from raw material supply area to demand area applying transport law was 964,600 thousands Won from 6 supply areas to 7 demand areas. And the result of each model's analysis to get the pellet's efficient production through production cost reduction showed that it reduced from 325,701 Won/t to 240,106 Won/t, results of existing efficient pellet for the production model 8,233 tons over 20,000 tons annual production capacity from the size of the expanded production capacity when the expansion. However, when the production size expanded to 50,000 Tons of the production, the effect was very small even though production cost decreased.

• Industrial Engineering and Management Systems
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• v.8 no.4
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• pp.213-220
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• 2009

A revenue sharing contract is one of the mechanisms that coordinate decision makers in a decentralized supply chain toward the consensual goal. The transfer prices between different echelons in the supply chain influence the total supply chain profits. The study aims to explore various transfer pricing heuristics on the supply chain coordination in terms of the supply chain profits and their interactions with the revenue sharing rate. A model is proposed for formulating the collaborative production and distribution planning in a decentralized supply chain with the revenue sharing mechanism. Experiment results indicate that the transfer price and the revenue sharing rate affect significantly the coordination. Among the studied pricing heuristics, the variable-cost pricing method led to the best SC profits. Raising the revenue sharing rate reduced the SC profits no matter what heuristics were employed. Furthermore, the experiments provide us clues for finding the optimal transfer price for the supply chain.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.1
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• pp.113-126
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• 2016

This study investigates the effect of power dynamics on R&D and market performances. Various types of relationships in a supply chain are considered. An R&D company offering new technology for product quality and a manufacturer responsible for both production and sales are utilized as subjects. The company with bargaining power differs with respect to the supply chain situation in practice, and no fixed single relationship and supply chain structure exist. However, only a few studies have considered the various relationships among players in a supply chain and their effects on performance. Therefore, we propose three models with different supply chain structures and power dynamics among players. This study contributes to the academia and supply chain practice by revealing the different characteristics of supply chain models.

• Asian Journal of Innovation and Policy
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• v.5 no.2
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• pp.116-128
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• 2016

Value chain analysis has been applied in various fields, from the time the concept of “value chain” was introduced by Porter in 1985. Several frameworks have emerged and have been used to study individual firms, entire industries, industry clusters, as well as global production networks. The purpose of this paper is to provide a brief review of these frameworks, identify factors that influence the performance of value chains, and suggest areas for future research. Since there is a wide range of value chain literature, this paper focuses on a selective set of earlier works within the value chain model as conceptualized by Porter. The study takes note of the many dimensions and applications of value chain analysis, and shows that value chain analysis is an effective way to examine the interaction among different players in a given industry. The study further points out the shortcomings of the traditional or Porter view of value chain analysis.

• Journal of the Korean association of regional geographers
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• v.13 no.2
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• pp.171-186
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• 2007

This paper was to examine the existing foundation of cultural contents industry through analyzing the development process, the location pattern, and the value chain system and the management of cultural contents industry in Daegu. Most cultural contents industry in Daegu had less than ten employees: so, it was classified into the early stage of commercialization. The firms that dealt with on-line distribution were recently founded. The high portion of the finns was located in the center of city such as Jung-Gu and Nam-Gu in which the Center for Digital Industry Promotion of Daegu (DIP) is located. The value main system consisted of four nodes such as creation node, production node, marketing node and distribution node. The production node was played the most important role. Based on value chain system, the cultural contents industry firms in Daegu could be divided into four types: Type I is a contents production firm with a single value chain in the cultural contents industry. Type II is a contents production firm with two or three value chains. Type III is a contents production firm with comprehensive value chain. Type IV is a non contents production firm with multiple value chains.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.523-528
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• 2013

This study investigates the effects of three branched-chain amino acids (BCAA; valine, leucine, and isoleucine) on the in vitro ruminal fermentation of wheat straw using batch cultures of mixed ruminal microorganisms. BCAA were added to the buffered ruminal fluid at a concentration of 0, 2, 4, 7, or 10 mmol/L. After 72 h of anaerobic incubation, pH, volatile fatty acids (VFA), and ammonia nitrogen ($NH_3$-N) in the ruminal fluid were determined. Dry matter (DM) and neutral detergent fiber (NDF) degradability were calculated after determining the DM and NDF in the original material and in the residue after incubation. The addition of valine, leucine, or isoleucine increased the total VFA yields ($p{\leq}0.001$). However, the total VFA yields did not increase with the increase of BCAA supplement level. Total branched-chain VFA yields linearly increased as the supplemental amount of BCAA increased (p<0.001). The molar proportions of acetate and propionate decreased, whereas that of butyrate increased with the addition of valine and isoleucine (p<0.05). Moreover, the proportions of propionate and butyrate decreased (p<0.01) with the addition of leucine. Meanwhile, the molar proportions of isobutyrate were increased and linearly decreased (p<0.001) by valine and leucine, respectively. The addition of leucine or isoleucine resulted in a linear (p<0.001) increase in the molar proportions of isovalerate. The degradability of NDF achieved the maximum when valine or isoleucine was added at 2 mmol/L. The results suggest that low concentrations of BCAA (2 mmol/L) allow more efficient regulation of ruminal fermentation in vitro, as indicated by higher VFA yield and NDF degradability. Therefore, the optimum initial dose of BCAA for in vitro ruminal fermentation is 2 mmol/L.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.5
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• pp.440-449
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• 2013

We consider a reverse supply chain with a production facility and a recovery facility, and address the joint control of production and disposal decisions for sustainable operations. Demands are satisfied from on-hand inventory of serviceable products, replenished via manufacturing or remanufacturing. Sold products may be returned after usage and each returned product is disposed of or accepted for recovery. Accepted returned products are converted into serviceable products after remanufacturing process. Formulating the model as a Markov decision process, we characterized the structure of the optimal production and disposal policy as two monotone switching curves under a special condition. Three types of heuristic policies are presented and their performance is numerically compared.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.131-140
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• 2004

The company was focusing on production which was partial mission rather than acquiring the information of customer in intensive process industry. The company accepted loss which is from over-production, losing of opportunity. After changing to web environment, supply chain is more complicated and need of customer is more various. As a result the company hard works on controlling production rates, production quantities in production area and gathering exact information which is about available resource and available quantities. Cooperated demand planning have to get decreasing of inventory, improving of customer service in supply chain management. Specially demand planning that considers allocation of capacity is executed in Iron-Industry. Demand planning must be classified by customer, region and supply position level.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.143-150
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• 2000

By successful establishment of SCM(Supply Chain Management) System they should make the supply chains speedy and combine production information system with the outcome system and thus they reinforce the competition of the production system of local enterprises in accordance with the rapid decision making This study is to develop the most appropriate production system models through the reflection of JIT system in the SCM which is the necessity of the times and its importance. To achieve this goal the researcher diversifies the prerequisites for the success of the business which will be the strategical factors of the production systems. The objects of this study is to develop the most appropriate production system models and to provide the enterprises with the models which are based on the SCM.