• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.525-529
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• 2016

Biomass co-firing to existing thermal power plants is one of the most economical and efficient way to reduce $CO_2$ emission from the plant. There are several methods of co-firing and it can be categorized into (1) Parallel co-firing, (2) Indirect co-firing, and (3) Direct co-firing. Parallel co-firing is the most expensive way to high-ratio co-firing because it requires biomass dedicated boiler. Direct co-firing is widely used because it does not need high capital cost compared with the other two methods. Regarding the direct co-firing, it can be classified into three methods- Method 1 does not need retrofit of the facilities because it uses existing coal mills for pulverizing biomass fuels. In this case high-ratio co-firing cannot be achieved because of poor grindability of biomass fuels. Method 2 needs biomass-dedicated mills and revision of fuel streams for the combustion system, and Method 3 needs additional retrofit of the boiler as well as biomass mills. It can achieve highest share of the biomass co-firing compared with other two methods. In Korea, many coal power plants have been adopting Method 1 for coping with RPS(Renewable portfolio standards). Higher co-firing ratio (> 5% thermal share) has not been considered in Korean power plants due to policy of limitation in biomass co-firing for securing REC(Renewable Energy Certificate). On the other hand, higher-share co-firing of biomass is widely used in Europe and US using biomass dedicated mills, following their policy to enhance utilization of renewable energy in those countries. Technical problems which can be caused by increasing share of the biomass in coal power plants are summarized and discussed in this report. $CO_2$ abatement will become more and more critical issues for coal power plants since Paris agreement(2015) and demand of higher share of biomass in the coal power plants will be rapidly increased in Korea as well. Torrefaction of the biomass can be one of the best options because torrefied biomass has higher heating value and grindability than other biomass fuels. Perspective of the biomass torrefaction for co-firing is discussed, and economic feasibility of biomass torrefaction will be crucial for implementation of this technology.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.5
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• pp.62-71
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• 2003

This study was carried out to develop the bio-chemical pulping method to enhance the energy saving and decrease the capital cost through the soda pulping under atmospheric pressure ($100^{\circ}C$). Nonwood substrates, rice straw, were pretreated by white-rot fungi, Pleurotus cornucopiae. Several basic pieces of data that can be applied in soda pulping were acquired. The results of this study were as follows. Under the conditions without any nutrients or with glucose, N and glucose + N, the weight losses of rice straws inoculated by Pleurotus cornucopiae were 12.1∼32.6 %, 12.0∼26.3 %, 13.0∼25.4 % and 15.3∼24.7 % for 5, 10, 15, 20, 25 and 30 days incubation periods respectively. The more the fungal incubation was extended, the more the weight losses were gained. The yield of untreated rice straw was 54.8 % after pulping. When any nutrients was not added or glucose, N and glucose ＋ N were added for the pretreatment, the total yields were ranged to 57.3∼42.9 %, 51.0∼43.3 %, 51.7∼43.9 % and 52.1∼46.1 % for 5 different incubation periods respectively. The yields were gradually decreased based on the extending of the incubation periods. The physical properties of the rice straw soda pulp without fungal treatment, the density, breaking length, burst index, tear index and folding endurance were 0.24g/㎤, 2.32 Km, 0.91 kPaㆍ$m^2$/g, 46.7 mNㆍ$m^2$/g and 21 times, respectively. In the case of pretreatment without any nutrients or with glucose, N and glucose + N as nutrients, the density was 0.24g/㎤, the breaking length was 3.30∼6.46 Km, the burst index was 1.36∼3.01 kPaㆍ$m^2$/g, the tear index was 33.0∼57.0 mNㆍ$m^2$/g and the folding endurance was 14∼381 times at most incubating periods, when pulping was done. The physical properties were increased as the incubation duration was extended. Especially, when N and glucose ＋ N were added, the physical properties showed superior results during each incubation period.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1996.05a
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• pp.91-115
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• 1996

In the recent years, protected horticultural facilities have been modernized and glasshouses are also propagating in Korea, even most vegetables production are conducted in the traditional plastic houses covered with, for example, PVC film for just temperature keeping. It would limit the productivity and competitivity of the vegetable production industry without automatization and high quality year round production. A plant factory, aimed to produce vegetables in the limited areas, was initiated in Christensen farm, Denmark in 1957, and widely propagated in some developed countries. As it has the automatized system which enables to keep optimized environment conditions, it will be the best facility for high quality products as well as year round planned production. However, we have not even started the plant factory production. Since the plant factory is requiring lots of resources, besides plant cultivation technologies, such as environment control, automatic engineering and robotics, our approach to the development of plant factories should be minded on Practical Plant Factories considering our current farming practices and least capital needs rather than blindly employing the advanced technologies from developed countries. Thus, Korean plant factory development can be initiated with year round leaf vegetables production in NFT or DFT cultivation system instead of the moval bed system, in which aerial environment factors such as light, temperature, humidity and CO$_2$ concentration and root environment ones such as solution concentration, temperature, pH and water soluble oxygen shall be automatically controlled. And the seeding, seedling and transplanting operations shall be accomplished in the house entrance, and the harvesting and grading opreations shall be conducted in the house exit. For practical plant factories, environment control technologies including artificial light source, illumination and air conditioning, automatic management for nutrient solution and automatic production line of moval bed system, transplanting and harvest should be developed along with researches on the cost reduction of factory building construction.

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.43-48
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• 2004

The development of the traffic system has brought relative reduction in aspect of the cost and time distance on the geographical space. SOC(social overhead capital), an express highway and railroad, has a great and absolute effect on the prosperity of community, As Mokpo is one of the community under the influence q West costal highway express and KTX(Korea Train Express), the number of the tourists visiting city of port like Mokpo has increasing gradually, especially at the high-demand season(in Summer). But the coastal passenger boot can't be capable of customers arriving at the port. As a result of this situation, the 'balking' occurs. No 'balking', means the jam of road. In this thesis, by understanding the concept and property of ARENA and simulating operation of coastal passenger boot at Mokpo port, intends to analyze the truth of 'balking' and finds an effective operation method of coastal passenger boot for the solution to the traffic jam. The solution to the jam in the vicinity of port of Mokpo, which try to develop tourism package commodity now, will present the effect of qualitative analysis in giving an opportunity of economic growth of the community, Mokpo.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.585-597
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• 2008

The aim of this study was to find an analytic solution to the problem of determining the optimal capacity (lot-size) of a batch-storage network to meet demand for a finished product in a system undergoing random failures of operating time and/or batch material. The superstructure of the plant considered here consists of a network of serially and/or parallel interlinked batch processes and storage units. The production processes transform a set of feedstock materials into another set of products with constant conversion factors. The final product demand flow is susceptible to short-term random variations in the cycle time and batch size as well as long-term variations in the average trend. Some of the production processes have random variations in product quantity. The spoiled materials are treated through regeneration or waste disposal processes. All other processes have random variations only in the cycle time. The objective function of the optimization is minimizing the total cost, which is composed of setup and inventory holding costs as well as the capital costs of constructing processes and storage units. A novel production and inventory analysis, the PSW (Periodic Square Wave) model, provides a judicious graphical method to find the upper and lower bounds of random flows. The advantage of this model is that it provides a set of simple analytic solutions while also maintaining a realistic description of the random material flows between processes and storage units; as a consequence of these analytic solutions, the computation burden is significantly reduced.

• 한국벤처창업학회:학술대회논문집
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• 2008.04a
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• pp.33-59
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• 2008

Since the late 20th century, due to the globalization of markets and the rapid developments of information and communication technologies, the world has entered into the age of fierce competition. With their abundant low-cost labor, former communist countries such as China, Russia and East Europe and low-developed countries such as India and Brazil have received investments from major industrial companies. There are no other alternatives for Korea and OECD countries to move the industrial economy to the knowledge based innovation system. In knowledge based innovation system, economic development and employment of a region and nation depend solely on the number of its companies and their competitiveness. In this research, after reviewing the current state of technological innovation small companies in korea, we provide a theoretical framework to promote the level of technological innovative entrepreneurship. The framework is based on a value system model that consist of supply factors, demand factors, and supporting institutions. In order to create more innovative small businesses, we insist on the followings. First, more R&D activities related with promising new technologies should be performed. Second, more R&D funds for technological innovation small companies should be provided from governments. Third, more M&A transactions and technology transactions should be marketed freely and competitively. Fourth, more business incubating services and venture capital services should be provided. Fifth, entrepreneurship and innovation culture should be popular and institutionized among people.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.67-77
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• 2000

For successful privatization of environmental facility, a sound environmental policy is required to satisfy social motivation and economic. The primary purpose of environmental facility is not profit, but to supply a good quality service, an efficient management tool is needed to run the facility. In foreign countries, the privatization policy was originally based on the principle of complete competition achieving economic effiency. There were efficient cooperation and division of labor between civillian and public sector. First of all, the local government had independant budget. But, we found that the environmental facility have two important problems, the first is low effiency of operation and the second is comsumed to government finances as a homemade rate 50% in the technic application For a successful privatization of the environmental facility, The law of private capital introduction should be amended to promote fund raising. There are some other strategies ; overcoming of Nimbyism, research development of the privatization, field trip to the successful foreign environmental facilities. To support an efficient privatization policy, the environmental budget should be managed by cost-benefit analysis.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.5
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• pp.81-91
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• 2016

The study shows solutions of long-term unexecuted urban park and activation plans to facilitate the business promotion of Private Park Developers. This study conducted a feasibility analysis to determine if the business of a special case is applicable. The result of this study is as follows about three long-term unexecuted urban parks in Gwangju Metropolitan City's City Park. First, the three long-term unexecuted urban parks in Gwangju Metropolitan City's City Park are the forest type Neighborhood Parks. Businesses of a special case's park developing cost(average 0.4%) have a relatively low percentage. It is most affected by Land Compensation(average 33.8%) and building construction expenses(average 59.1%). Second, long-term unexecuted urban parks' Land Compensation and building construction expenses seed capital are excessive. The Bongsan Park balance floor space index is 179 percent; a reasonable profit floor space index is 220 percent. The Mareuk Park balance floor space index is 351 percent; a reasonable profit floor space index is 420 percent. The Jungoe Park balance floor space index is 327 percent; a reasonable profit floor space index is 400 percent. Third, to facilitate the business of special cases in deliberating, Bongsan Park should change its second class general residential area. Jungoe Park must change the quasi-residential area and semi-residential area. Mareuk Park must change the general commercial area. In this way, the feasibility of promoting private park projects will be improved.

• Journal of the Korea Society of Computer and Information
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• v.17 no.3
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• pp.185-191
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• 2012

The essence of Mutual aid service is looking into the general commerce about its goods and services that is a general viewpoint. Through the contract that the contractor related with the Mutual aid associations and Mutual aid companies. provide the goods and services to future member's demanding point. and members are pay out money, and pay for that on the installment plan. This Mutual aid business had been increased rapidly after 2005, it is expanded huge business, even its scale alone, the cost is estimated at over three trillion won. But because of Mutual aid business's prepayment installment plan, stipulated substance of the Law on hire-purchase systems were more actualized than in the past, but it leave much to be desired. for example, the obligation of explanation to Mutual aid associations and members of Mutual aid company, the consumer protection about the contract of advance received deposit, upward problem of capital, when establish the Mutual aid company etc. in this paper will review these problems and improvement about legal details that for the customers of Mutual aid service and development of Mutual aid industry, and claimed about Mutual aid law's singular legislation.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.99-112
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• 2014

This study the impact on the real earnings management credit rating (RANK), and looked at the impact on the real earnings management grade credit rating changes (decrease, increase) the effects in detail. firm for a total of 06 years for firm that are listed on the Korea Stock Exchange from 2008 to 2013 for the hypothesis - using the proceeds of the year 2,583 sample were analyzed to study. A regression analysis of the relevance of the credit rating (RANK) and real earnings measured results between the credit rating and a measure of real earnings management ACFO and ADE (+) between AMC (-) IFRS and receive relevant ADE between(+) between AMC (-) if the credit rating (RANK) is increased ACFO and is significantly sound level at 1% showed the relevance of (+) did not significantly ADE (+) 10% of AMC if the credit rating fell ACFO is (-) from AMC show the relevance of positive credit rating is dropped capital letter showed for performing real earnings management of positive even give up the future cash flow in order to reduce the cost.