• Journal of Environmental Science International
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• v.16 no.11
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• pp.1271-1277
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• 2007

This study was conducted to investigate the ratios of phosphorus release to COD uptake, phosphorus release to nitrate removal, and phosphorus uptake to phosphorus release by DNPAOs(denitrifying phosphate accumulating organisms). In case $I{\sim}IV$, influent 1 were fed with synthetic wastewater with influent 2 $NO_3^--N$ injection to anoxic zone and the case V were fed with municipal wastewater with side stream oxic zone instead of influent 2 $NO_3^--N$ injection. As a result, the ratio of phosphorus release to carbon uptake was increased in accordance with nitrate supply. The DNPAOs simultaneously took up phosphate and removed nitrate from the anoxic reactor. In case $I{\sim}IV$, with above 20 mg/L of sufficient $NO_3^--N$ supply, phosphate was taken up excessively by the DNPAOs in anoxic condition. The large amount of both uptake and release of phosphorus occurred above 20 mg/L of nitrate supply, achieving the ratio of phosphorus uptake to phosphorus release to be 1.05. In case V, phosphate luxury uptake was not occurred in system due to 6.98 mg/L of insufficient $NO_3^--N$ supply and the ratio of phosphorus uptake to phosphorus release was 0.98. Consequently, if nitrate as the electron acceptor was sufficient in anoxic zone, the ratio was found to be high.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.72-81
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• 2009

This paper presents quasi-resonant type high power factor ac power supply for atmospheric pressure plasma cleaning system adopting three phase PFC boost converter and it's control method. The presented ac power supply consists of single phase H-bridge inverter, step-up transformer for generating high voltage and three phase PFC boost converter for high power factor on source utility. Unlikely to the traditional LC resonant converter, the propose one has an inductor inside only. A single resonant takes place through the inside inductor and the capacitor from the plasma load modeled into two series capacitor and one resistance. The quasi-resonant can be achieved by cutting the switching signal when the load current decrease to zero. To obtain power control ability, the propose converter controlled by two control schemes. One is the changing output pulse period scheme in the manner of PFM(Pulse Frequency Modulation) control. On the other, to provide more higher power to load, the DC rail voltage is directly controlled by the 3-phase PFC boost converter. The significant merits of the proposed converter are the uniform power providing capability for high quality plasma generation and low reactive power in AC and DC side. The proposed work is verified through digital simulation and experimental implementation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.3
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• pp.273-277
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• 2016

In this paper, we deals with the digitization of high frequency sine wave power supply using power source of high frequency surgical equipment and RF device. High frequency surgical equipment has been using commonly on medical surgery because of its merits such as programmable depth of incision, availability of incision and coagulation in the same device, increasing the usability on surgical side. However, the core part of the device is consists of vacuum tubes which are expensive, not ease to use and must be imported, therefore it is inevitable of high prices, forces to develop the fully digitized alternative technology. The fully digitized high frequency sine wave power supply for surgical device is proposed and verified by experimental results.

• Environmental and Resource Economics Review
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• v.26 no.2
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• pp.173-203
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• 2017

The existence of rebound effect from road extension in Korea has been quantitatively verified using cross-sectional, time series data on four major cities - Seoul, Busan, Daegue and Incheon - between 2000 and 2013. The linear mixed effects model was constructed from six variables: total vehicle miles traveled (VMT), road extension, public transport users, gross regional domestic product (GRDP), regional population and fuel consumption. The main results can be summarized as VMT is positively correlated to road extension while negatively with public transport users. It indicates that the road extension-centered "supply-side" transportation policy induces "additional travel" and create "generated traffic" by enhancing driving efficiencies directly, or degrading other transport modes indirectly. Hence, the ultimate goal of road congestion reduction requires public transport-centered "demand management" rather than current supply-side policies.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.3
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• pp.15-26
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• 2015

This paper reviews the theoretical background of the entrepreneurship policy recently prevailing in Korea. First of all, we define the entrepreneurship policy as the one that the government increases the supply of the individual entrepreneurs with entrepreneurship and supports their venture creation activities by intervening the entrepreneurial process. We distinguish the entrepreneurship policy from the small and medium-sized enterprises policy and the venture firm policy. As for the legitimacy of the entrepreneurship policy, we introduce the market for entrepreneur, examine the factors resulting in the market failure, and argue the necessity and the principles of government intervention to the market. Based on the entrepreneurial process, we establish the framework of entrepreneurship policy and examine the transmission channels by the policy area. The channels are (1) demand side, (2) supply side, (3) decision-making of establishing a new firm, (4) resources obtaining. Lastly, according to the transmission channels, we classify various entrepreneurship policy tools being presently implemented by the Korean government. However, since this study is a exploratory economic analysis of entrepreneurship policy, the approach and contents of entrepreneurship policy can be varied according to the research agenda and policy intension.

• Korean Management Science Review
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• v.17 no.1
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• pp.117-134
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• 2000

Pubilc utility industries including the electric utility industry are facing a new stream of privatization com-petition with the private sector and deregulation. The necewssity to solve now and in the future power supply and demand problems has been increasing through the sophisticated generation expansion plan(GEP) approach con-sidering not only KEPCo's supply-side resources but also outside resources such as non-utility generation(NUG) demand-side management (DSM). Under the environmental situation in the current electric utility industry a new approach is needed to acquire multiple resources competitively. This study presents the development of a modified electric generation expansion analysis system(EGEAS) model with avoided cost based on the existing EGEAS model which is a dynamic program to develope an optimal generation expansion plan for the electric utility. We are trying to find optimal GEP in Korea's case using our modified model and observe the difference for the level of reliabilities such as the reserve margin(RM) loss of load probability(LOLP) and expected unserved energy percent(EUEP) between the existing EGEAS model and our model. In addition we are trying to calculate avoided cost for NUG resources which is a criterion to evaluate herem and test possibility of connection calculation of avoided cost with GEP implementation using our modified model. The results of our case study are as follows. First we were able to find that the generation expansion plan and reliability measures were largely influenced by capacity size and loading status of NUG resources, Second we were able to find that avoided cost which are criteria to evaluate NUG resources could be calculated by using our modified EGEAS model with avoided cost. We also note that avoided costs were calculated by our model in connection with generation expansion plans.

• Journal of the Korean Society for information Management
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• v.31 no.3
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• pp.89-110
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• 2014

In this study, we analyzed KERIS Document Delivery Service (DDS) using its transaction data for the period of nine years from 2004 to 2012. We first examined the overall statistics focusing on member contributions, and conducted a network analysis based on the records of request/response (supply) between member libraries. Key findings include the following: First, in over 80% of member libraries, the number of outgoing requests exceeded the number of their responses to incoming requests. That is, for the vast majority of member libraries, their participation was concentrated on the request side. Second, KERIS DDS relies heavily on a relatively small number of top contributors, especially on the supply side. While the top contributors were active in both requests and responses (supplies), in most cases, they received and processed a disproportionally large number of requests. Third, the network analysis based on DDS requests for journal articles in 2012 further revealed the central role of top contributors. The level and pattern of concentration, however, appeared to differ by subjects (DDC). Three main patterns of centralization were found in different subjects - a network centered on a single member, a network having multiple centers, or a distributed network.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.78-83
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• 2009

Since modern times, lack of housing had become more serious in the cities when going through urbanization process. As a countermeasure against the situation, multi-family houses raised its head at the end of 1980s. Regarding multi-family houses, which is mainly targeting low-income group, however, only quantitative supply has been focused with no enough research about space planning. For now that the supply of housing in the cities reached certain level, there is a need of planning multi-family house considering the demands of residents. Therefore, the purpose of this research is to identify and analyze the demands of owners and tenants of multi-family house in an improvement district of housing environment for housing improvement, and to extract house planning components. As a research methodology, small-group workshop panel using drawings and mock-up has been practiced to reach residents' concertized opinion. After dividing the residents group into 2 groups which include owners group(3 participants) and tenants group(3 participants), 3 times of workshops covering 2 days are conducted for each group. Actual-condition investigation of the participants' houses was ran side by side with workshop. As a result, difference in their point of view about the reasons and the direction of housing improvement was identified, on the other hand that there is similarity in their demands such as guaranteeing independency and privacy among households.

• STI Policy Review
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• v.5 no.1
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• pp.75-97
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• 2014

Entrepreneurial financing, such as publicly initiated venture capital or grant schemes, serves as an important policy instrument that aims to bridge the financing gap facing young, innovative businesses, a gap that is mainly due to higher risk and growing uncertainty, and to strategically promote the creation of new ventures through the revitalization of their venture capital industries. This study examines public venture capital initiatives in Australia, Canada, and Sweden, and discovered that all three countries actively foster their venture capital industry through the formation of funds or the provision of tax incentives. It is notable that the majority of financing initiatives heavily depend on supply-side measures rather than demand-driven policies that focus on stimulating private investment in technological innovations and discoveries. This paper discusses in-depth the policy impact of public financing initiatives and their subsequent side-effects raised in the process such as overlapping in funding structure across the country, lack of monitoring and evaluation for feedback, fragmentation across the government ministries and agencies, and competition with the private sector, which may cause inefficiency as a result of public intervention. Financial constraints may arise for many reasons, partly resulting from the lack of investment readiness of young entrepreneurs. This signals a policy shift towards the creation of market-driven demand away from the traditional supply-push approach, and is a grand challenge to policymakers in entrepreneurial financing. Attention is leaning towards the efficiency and effectiveness of these public-financing initiatives in terms of their policy roles. It is worth noting that policy should focus on generating synergy so available resources can be channeled into the early, risky stage of new ventures, working as facilitator to the achievement of an intended policy goal.

• Membrane Journal
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• v.29 no.6
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• pp.323-328
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• 2019

It is a highly important problem for mankind to supply sufficient energy, which has been connected to production and supply of electricity. In terms of the problems, this study fabricated a new sort of solid polymer electrolyte membrane for supercapacitors. The fabricated electrolyte employed grafting poly(oxyethylene methacrylate) (POEM) side chain on poly(vinyl alcohol) (PVA) main chain by free-radical polymerization. It is the first time to utilize PVA-g-POEM graft copolymer as an electrolyte membrane for supercapacitor. The chain behavior of PVA was transformed by grafting POEM side chains, which was analyzed by FT-IR spectra. Also, the capacitance performances of fabricated supercapacitors were explored by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and ragone plot. We suggest a new point, the grafting of the electrolyte of supercapacitor in this study.