• Industrial Engineering and Management Systems
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• v.16 no.1
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• pp.22-43
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• 2017

It is urgently-needed to construct a green supply chain (GSC) from collection of used products through recycling of them to sales of products using the recycled parts. Besides, it is necessary to consider the uncertainty in product demand as a risk in a GSC. This study proposes the optimal operations for a GSC with a retailer and a manufacturer. A retailer pays an incentive for collection of used products from customers and sells a single type of products in a market. A manufacturer produces the products ordered by the retailer, using recyclable parts with acceptable quality and compensates the collection cost of used products as to the recycled parts. This paper discusses the following risk attitudes: risk-neutral attitude, risk-averse attitude, and risk-prone attitude. Using mean-variance analysis, the optimal decisions for product order quantity, collection incentive, and lower limit of quality level, in the decentralized GSC (DGSC) and the integrated GSC (IGSC) are made. DGSC optimizes the utility function of each member. IGSC does that of the whole system. The analysis numerically investigates how (i) risk attitude and (ii) quality of recyclable parts affect the optimal operations. Supply chain coordination between GSC members to shift IGSC from DGSC is discussed.

• Korean Management Science Review
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• v.29 no.1
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• pp.153-168
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• 2012

Order allocation is one of the most important decision-making problems of firms having significant influences on performances of themselves and the whole supply chain. Existing researches about order allocation have mainly focused on evaluating capabilities of directly connected suppliers so that it is hard to consider effects and interactions from undirected connections over multiple lower-layers. To alleviate the limitation, this paper proposed a novel approach to order allocation using structural hole. By applying the concept of structural hole to the supply network, we could evaluate the structural supplying powers of firms with respect to both of direct and indirect connections. In the proposed approach, we derived a methodology to measure the potential supplying power of each firm by modifying the effective size as one of the measurements of structural hole and then, proposed its application, the structural hole based order allocation strategy. Furthermore, we conducted the agent based modeling of supply chain to perform the decision-making process of order allocation and simulated the proposed strategy. As a results, by coping with the variance of demand more stably, it could improve the performance of supply chain from the aspects of fill rate, inventory level and demand-supply balance.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.423-426
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• 2003

The purpose of this paper is to estimate Agricultural water demand at irrigation area of sumjin reservoir, the Dongjin River basin, which consist of multi-wide water supply system and complicated irrigation channel and supplementary irrigation facilities.

• Journal of Korean Society for Quality Management
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• v.21 no.1
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• pp.11-21
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• 1993

In this paper, we survey the current status of measurement labor in Korean Industry. At the same time we try to predit the demand and supply of measurement labor to suggest policy measures for equilibrium in measurement labor market. We use a general production function for the prediction which include a set of general homethetic production function.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.341-352
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• 2017

Regarding "Supply-side Structural Reforms of Chinese Cultural Industry(供給側結枸性改革)" that has been genuinely promoted since 2016 in China, this study aims to analyze research trends in academic circles and policies carried out by the government and draw implications about what culture industry should pursue in Korea. First of all, research conducted through industrial-educational cooperation mainly and commonly points out such problems as imbalance between demand and supply, oversupply, low culture consumption, absurdity in loans and investments structures, and lack of international influence and demands reformation. In the side of the government, <13.5 Plan for Developing Culture Industry promoted from 2016 to 2020 reflects the government's strong will taking structural reformation in the side of supply as its major route and presenting tasks to reform culture industry in general. Next, concerning implications for Korea, this author suggests them in five areas: to establish directions for new culture industry policies reflecting the changes of environment in culture industry, say, the advent of the 4th industrial revolution, to increase valid supply correspondingly to consumer demand, to improve loans and investments systems, to enlarge demand markets, and to form environment for fair market competition.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.3
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• pp.183-201
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• 2022

In this study, economic feasibility analysis was performed when various hydrogen production and transport technologies were applied to derive hydrogen supply plans by period. The cost of hydrogen may vary depending on several reasons; configuration of the entire cycle supply path from production, storage/transportation, and utilization to the cost that can be supplied to consumers. In this analysis, the hydrogen supply price according to the hydrogen supply route configuration for each period was analyzed for the transportation hydrogen demand in metropolitan area, where the demand for hydrogen is expected to be the highest due to the expansion of hydrogen supply.

• Journal of Aerospace System Engineering
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• v.8 no.3
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• pp.34-40
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• 2014

Since the global economic crisis in year 2008, the world civil helicopter market has been growing recently. According to the market outlook in the next decade, the demand of civil helicopter will be driven by the demand of Private & Corporate, Oil & Gas, Off-shore and EMS(Emergency Medical Service) usages. On the other side, the demand of military market will be driven by the modification and upgrading for life extension or performance enhancement than the new helicopter development for replacing old models. To summarize these situations, the demand of MRO(Maintenance, Repair & Overhaul) market has also been on the rise because of the demand due to above several usages in civil side and the life-extension in military side. Through the MRO market analysis for characteristics, developmental trends and a supply chain, this paper describes that the potential of MRO business is considerably large as a propulsive power of domestic helicopter industry. And also, it proposes the construction direction of MRO network because the domestic industry must make the developmental awareness and reliability a stepping-stone towards own helicopter.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.49-56
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• 2012

The purpose of this paper is to present a model for operating an emergency power system(EPS) that can secure a sufficient power supply used in case of a fire by analyzing the status of power supplies for emergency and firefighting operations. Investigations on the one of the causes of the operational failure of firefighting systems show evidence of EPS. Generally, when power to a building is interrupted, EPS supplies the emergency load(excepted firefighting load) first. When a power outage and a fire occur simultaneously, the EPS must be able to supply both the emergency load and the firefighting load, especially the firefighting load to the end. However, in order to save construction costs, emergency power generators in apartment, commercial, and business buildings can satisfy only one of the required loads. In cases like this, when a power outage and a fire occur simultaneously, there is a danger of firefighting equipment not operating due to insufficient power supply from the emergency generator. Therefore, an EPS must have a reserved firefighting power that can supply both the firefighting and the emergency load. Such EPS, when faced with a danger of an overload, will shut down the supply to all or part of the emergency load, thus securing a continuous power supply to the firefighting equipment. The generator power system with reserved firefighting power (RFP) will also have an indicator to show that the selective control is being used. General power generation systems for emergency load and firefighting load were found to have a demand factor of 50-60% with a lump. However, when installing an EPS, the builders must choose the higher demand factor suggested according to the official approval demand factor of the building.

• Management & Information Systems Review
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• v.27
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• pp.149-172
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• 2008

Since the 9/11 terror attack, the event which caused supply chain disruption, supply chain security has becomes more important than ever before. Furthermore, such company's logistics strategies conflicting supply chain security as increased global sourcing, JIT manufacturing are increasing supply chain vulnerability. It could burden for global companies to strengthen supply chain security because not only it requires additional investment cost but also changes of companiy's global logistics strategy. However, on the other hand, supply chain visibility and resilience can be improved through supply chain security. In addition, it allows companies to stabilize supply chain structure as well as rapid and flexible response to market demand. The key issue is balancing between efficiency and supply chain security. To do this, identifying risk elements under the supply chain and assessing vulnerability of each supply chain components should be performed before developing efficient supply chain security management system without obstructing supply chain efficiency.

• Journal of Digital Convergence
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• v.8 no.2
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• pp.103-114
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• 2010

People generally focus on the supply side when conducting a study on the movie industry. However, to understand the movie industry better, one needs to analyze both sides - the demand and supply of movies. This paper analyzes demand-side factors that have long been taken for granted in Korea's movie industry. The study used data for 1991~2008 on the following demand-factors : the average ticket prices, the number of working days and hours, the average personal income, the number of spectators for the two major professional sports, cable TV, the number of movies released each year and the number of movie screens. This study shows that ticket prices do not conform to the law of demand. According to the law of demand, increasing price leads to a decline in demand. However, in reality, the number of viewers went up along with ticket prices. The study found that demand for movies was correlated to income levels and leisure time. An increase in the number of leisure hours and income levels pushed up demand. Contrary to general belief, a growth in the availability of substitutes, such as professional sports(soccer and baseball), did not result in a fall in demand for movies. The audiences for both sports and movies grew simultaneously as the amount of leisure time increased. Contrary to the general expectations that more diversified genres of movies will draw larger audiences by satisfying different individual tastes, the diversification had little impact, but the number of movie screens was positively correlated with audience size. In sum, changes in ticket prices and the quantity of substitutes had little influence on demand in the movie industry. Rather, it was the supply side of the industry that induced demand.