• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.249-255
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• 2009

The performance of microbial fuel cell (MFC) can be affected by many factors including the rate of organic matter oxidation, the electron transfer to electrode by electrochemical bacteria, proton diffusion, the concentration of electron acceptor, the rate of electron acceptor reduction and internal resistance. the performance of MFC using oxygen as electron acceptor can be influenced by oxygen concentration as limit factors in cathode compartment. Many studies have been performed to enhance electricity production from MFC. The series or parallel stacked MFC connected several MFC units can use to increase voltages and currents produced from MFCs. In this study, a single MFC (S-MFC) and a stacked MFC (ST-MFC) using acetate as electron donor and oxygen as electron acceptor were used to investigate the influence of dissolved oxygen (DO) concentrations in cathode compartment on MFC performance. The power density (W/$m^3$) of S-MFC was in order DO 5 > 3 > 7 > 9 mg/L, the maximum power density (W/$m^3$) of S-MFC was 42 W/$m^3$ at DO 5 mg/L. The power density (W/$m^3$) of ST-MFC was in order DO 5 > 7 > 9 > 3 mg/L and the maximum power density (W/$m^3$) of STMFC was 20 W/$m^3$ at DO 5 mg/L. These results suggest that the DO concentration of cathode chamber should be considered as important limit factor of MFC operation and design for stacked MFC as well as single MFC. The results of ST-MFC operation showed the voltage decrease of some MFC units by salt formation on the surface of anode, resulting in decrease total voltage of ST-MFC. Therefore, connecting MFC units in parallel might be more appropriate way than series connections to enhance power production of stacked MFC.

• Membrane Journal
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• v.9 no.4
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• pp.230-239
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• 1999

Perchlorate ion-selective electrodes in PVC membranes that respond linearly to concentration 106 M were developed by incorporating the quaternary phosphonium salts as a canier. The effects of the chemical structure, the contents of canier, the kind of plasticizer and the membrane thickness on electrode characteristics such as the electrode slope, the linear respone range and the detection limit were studied. With this results, the detectable pH range, selectivity coefficients and AC impedance characteristics were compared and investigated. The perchlorate ion substituents of the quaternary phosphonium salts like tetraoctylphosphonium perchlorate (TOPP) , tetraphenylphosphonium perchlorate(TPPP), and tetrabutylphosphonium perchlorate(TBPP) as a canier were used. The electrode characteristics were better in the ascending order of TBPP < TPPP < TOPP, with the increase of carbon chain length of the alkyl group. Dioctylsebacate(OOS) was best as a plasticizer, the canier contents were better with 11.76 wt% and the optimum membrane thickness was 0.19 mm. Under the above condition, the electrode slope was 56.58 mV/$^P{ClO}_4$,the linear response range was $10^{-1}$\times$10^{-6}$ M, the detection limit was 9.66 x $10^{-7}$ M. The performance of electrode was better than Orion electrode. The electrode potential was stable within the pH range from 3 to 11. The order of the selectivity coefficients for the perchlorate ion was sol < F < Br < 1. With the result of impedance spectrum, it was found that the equivalent circuit for the electrode could be expressed by a series combination of solution resistance, parallel circuit consisting of the double layer capacitance and bulk resistance and Warburg impedance. And solution resistance was almost not appeared and Warburg impedance was highly appeared by diffusion. Then Warburg coefficient was 1.32$\times$$10^74 $\Omega$ $\cdot$ ${cm}^2/s^{1/2}$.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.5
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• pp.69-81
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• 2014

There is a growing interest in the technology transfer and commercialization both at home and abroad. Accordingly, this study looked at the concept of technology transfer and commercialization, identified the factors that should be taken into account in order to facilitate technology transfer and commercialization, and then performed a empirical analysis. As for the conventional technology transfer and commercialization, there was a tendency to limit its scope to the exploration, transfer and commercialization of technology itself. Here in this research, technology transfer and commercialization is defined the category to expand as various activities implemented in order to make sure that intellectual properties such as intangible technological developments, know-how, and knowledge are transferred between the relevant parties through a contract or negotiation, and the party to which the transfer is made can then further develop and exploit the technology into tangible products and other activities to obtain economic benefit out of that. In addition, the findings of the positive analysis of technology transfer and commercialization revealed that the focus of facilitating technology transfer has been on the technology itself, its management and securing efficiency of the systems and institutions involved in the technology transfer and commercialization. So there was lack of recognition as to the importance of financial support given to the phase of technology commercialization. This indicates that when it comes to the technology transfer and commercialization, quantitative performance has been the focus of interest such as patent application, registration, number of technology transfers, royalty, etc. So there was not enough understanding as to the issues of starting up a business, creating quality jobs through technology transfer and commercialization, which are directly related to the realization of the creative economy. In this regard, this research is expected to be used for the development for the future policies to boost technology transfer and commercialization as it suggests not only simply ensuring quantitative performance but also necessary to create the environment for the creation of the stable ecosystem for the parties involved in the technology transfer and commercialization and then to build circumstances in which creative economy can be realized.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.203-215
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• 2017

Recently, interest in Pedestrian Navigation Service (PNS) is being increased due to the diffusion of smart phone and the improvement of location determination technology and it is efficient to use landmarks in route guidance for pedestrians due to the characteristics of pedestrians' movement and success rate of path finding. Accordingly, researches on extracting landmarks have been progressed. However, preceding researches have a limit that they only considered the difference between buildings and did not consider visual attention of maps in display of PNS. This study improves this problem by defining building attributes as local variable and global variable. Local variables reflect the saliency of buildings by representing the difference between buildings and global variables reflects the visual attention by representing the inherent characteristics of buildings. Also, this study considers the connectivity of network and solves the overlapping problem of landmark candidate groups by network voronoi diagram. To extract landmarks, we defined building attribute data based on preceding researches. Next, we selected a choice point for pedestrians in pedestrian network data, and determined landmark candidate groups at each choice point. Building attribute data were calculated in the extracted landmark candidate groups and finally landmarks were extracted by principal component analysis. We applied the proposed method to a part of Gwanak-gu, Seoul and this study evaluated the extracted landmarks by making a comparison with labels and landmarks used by portal sites such as the NAVER and the DAUM. In conclusion, 132 landmarks (60.3%) among 219 landmarks of the NAVER and the DAUM were extracted by the proposed method and we confirmed that 228 landmarks which there are not labels or landmarks in the NAVER and the DAUM were helpful to determine a change of direction in path finding of local level.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.149-156
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• 2013

In this paper, the Constitutional Court's ruling through the SNS was virtually guaranteed the freedom of election campaign through, though, still a large portion of campaign restrictions on public election law provisions exist to this forward in the election is likely to cause a lot of legal problems. In this paper, the Constitutional Court's ruling through the SNS was virtually guaranteed the freedom of election campaign through, though, still a large portion of campaign restrictions on public election law provisions exist to this forward in the election is likely to cause a lot of legal problems. Moreover, in the mean time the campaign and which in the course of the election campaign through the SNS, the infinite potential of the growing point than any point spread from the SNS and freedom of election campaign through public election law with regard to the limitation of the diffusion of false facts, awards, a number of problems are likely to occur. You've been in this business and disseminate false guilt disparage precandidacy for true-false, as well. He should be able to reach a specific goal you want to defeat through the dissemination of information which is specified as a crime for this strictly for the fact that disseminate false, rather than to interpret it is the judgment of the Court in that judgment against have been made. Therefore, this strict interpretation of the law and the need to revise or delete before I would like to discuss about. The legislation would repeal the cull of Ron sang first of all point out the issue through analytics. First, the purpose of the data protection Act provides limited interpretation to fit in this world of sin. Secondly, this sin is committed for the purpose of prevention, since the purpose of the objective in this case of sin and the need to interpret strictly. Why I am the Internet space in the case of so-called tweets from followers, this means in some cases done without a lot of the stars because of this, there will be a limit to the punishment of sin, this is obvious. And, in the long-awaited Constitutional Court ensures the freedom of election campaign through SNS and free election in the country, even in the limited sense interpretation opens the chapter of communication is needed. This ensured the freedom of expression will be highly this is a mature civil society that will be imperative.