• 대한방사선기술학회지:방사선기술과학
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• 제43권4호
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• pp.289-295
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• 2020

This study investigated the feasibility of establishing a college of medicine in the western region of Chungnam to fill the gap in the medical doctor in charge of essential medical care in the region. Currently, the level of medical services in Chungnam is low compared to provinces across the country and in particular, 7 cities and towns, which account for 760,000 people, one-third of Chungnam's population, are located in the western regions of Chungnam. Because of this, in the event of an emergency patients, it is necessary to travel to Cheonan, Daejeon, Seoul, etc. where the regional emergency medical center is located for more than 1 hour and 30 minutes. In the case of critically ill and emergency patients transfer, it is a situation that misses the golden time and causes valuable loss of life. In order to improve the medical environment in the western region of Chungnam and improve the lives of residents in vulnerable areas of medical services, it is believed that establishing a college of medicine in the western region of Chungnam is essential.

• 한국수소및신에너지학회논문집
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• 제17권2호
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• pp.133-140
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• 2006

The performance of proton exchange membrane fuel cell was decreased by reverse voltage using fuel starvation. Performance decrease in local area could be affected by duration and extent of reverse voltage. Hydrogen and air stoichiometic ratio was used to find the experimental condition of abrupt voltage decrease. LabVIEW was used to make control logic of automatic load off system in preset voltage. Reverse voltage experiment was done down to -1.2 V at constant current condition. When fuel cell voltage was reached to preset voltage, electronic load was disconnected to make open circuit voltage for 1 minute. Fuel cell performance was checked every 5 cycle and the degree of performance decrease and/or recovery was estimated. Ohmic resistance and charge transfer resistance were increased and platinum surface area was reduced 41% after reverse voltage experiment.

• 한국건설관리학회논문집
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• 제10권5호
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• pp.57-66
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• 2009

본 연구는 BTL사업 실시협약을 위한 협상단계에서의 쟁점이 되는 항목의 분석 및 그 발생 원인을 찾아보고 해결방안을 제시하고자 하였다. 이에 기 수행되었거나 또는 수행중인 협상에서 논의되고 쟁점화 되는 항목에 관하여 주무관청과 사업참여자를 대상으로 협상참여 주체들이 인식하고 있는 쟁점화정도를 분석하였다. 또한 협상단계 각 분야별 쟁점항목들의 계층 분석방법을 통한 쌍대비교를 통해 가중치를 산정하고 그 쟁점화정도를 정량적으로 도출하였다. 최종적으로 1차 계층의 6개 협상분야 중 4개 분야에 대한 발생원인 각 2개, 2개 분야에 대한 발생원인 각 1개를 도출한 후 그에 대한 해결방안을 제시하였다.

• 전기화학회지
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• 제8권2호
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• pp.106-114
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• 2005

This article covers the theoretical ac-impedance models for the analysis of oxygen reduction on the porous cathode electrode f3r solid oxide fuel cell (SOFC). Firstly, ac-impedance models were explained on the basis of the mechanism of oxygen reduction, which were classified into the rate-determining steps; (i) adsorption of oxygen atom on the electrode surface, (ii) diffusion of adsorbed oxygen atom along the electrode surface towards the three-phase (electrode/electrolyte/gas) boundaries, (iii) surface diffusion of adsorbed oxygen atom m ixed with the adsorption reaction of oxygen atom on the electrode surface and (iv) diffusion of oxygen vacancy through the electrode coupled with the charge transfer reaction at the electrode/gas interface. In each section for ac-impedance model, the representative impedance plots and the interpretation of important parameters attributed to the oxygen reduction reaction were explained. Finally, we discussed in detail the applications of the proposed theoretical ac-impedance models to the real electrode of SOFC system.

• Journal of Electrical Engineering and Technology
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• 제4권1호
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• pp.106-110
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• 2009

An amperometric glucose biosensor has been developed using viologen derivatives as a charge transfer mediator between a glucose oxidase (GOD) and a gold electrode. A highly stable self-assembled monolayer (SAM) of thiol-based viologen was immobilized onto the gold electrode of a quartz crystal microbalance (QCM) and GOD was immobilized onto the viologen modified electrode. This biosensor response to glucose was evaluated amperometrically in the potential of -300mV. Upon immobilization of the glucose oxidase onto the viologen modified electrode, the biosensor showed rapid response towards glucose. Experimental conditions influencing the biosensor performance, such as pH potential, were optimized and assessed. This biosensor offered excellent electrochemical responses for glucose concentration below ${\mu}$ mol level with high sensitivity and selectivity and short response time. The levels of the RSDs (<5%) for the entire analyses reflected the highly reproducible sensor performance. A linear calibration range between the current and the glucose concentration was obtained up to $4.5{\times}10^{-4}M$. The detection limit was determined to be $3.0{\times}10^{-6}M$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1330-1332
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• 2006

In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The agobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the Presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1305-1306
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• 2006

A monolayer assembly of anthracene-viologen linked thiol ($AMVC_{8}SH$) was fabricated on a gold electrode by self-assembly method. Structural property of the self-assembled monolayers (SAMs) was carried out by optical and electrochemical method. Firstly, we investigated PL spectrum and UV/visible absorption for the optical properties in solution state. Secondly, we determined the characteristics of charge transfer in different electrolyte solutions by electrochemical quartz crystal microbalance (EQCM). From the data, the PL spectrum and UV/visible absorption were observed and the well-defined shape peaks were nearly equal charges during redox reactions and existed to an excellent linear relationship between the scan rates and existed to currents. The mass change was determined during redox reaction. The mass change behavior of SAMs was not only governed by the mobility of the ion in the viologen but the valence of the ion in the electrolyte solution.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.209-211
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• 2004

In the Langmuir-Boldgett(LB) technique, a monolayer on the water surface is transferred on to a substrate, which is raised and dipped through the surface, and one can obtain multilayers in which constituent molecules periodically are arranged in layer. The LB technique has attracted considerable interest in the fabrication of electrical and electronic device, e.g.. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules sharacterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends, which distinguishes dendrimers from conventional starlike polymers and microgels. Azobenzene dendrimer is one of the dendritic macromolecules that includes the azo-group which exhibits a photochromic character. Due to the presence of the charge transfer part, the azo-group, and having a rod-shaped structure, these compounds are expected to have the potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give a pressure stimulation into organic thin films and detect the induced displacement current.

• 전기학회논문지
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• 제58권11호
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• pp.2214-2218
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• 2009

Dye-sensitized solar cell (DSC) has been considered as a possible alternative to current silicon based p-n junction photovoltaic devices due to its advantages of high efficiency, simple fabrication process and low production cost. Numerous researches for high efficient DSC in the various fields are under way even now. Among them, the compact layer, which prevents the back electron transfer between transparent conductive oxides and the redox electrolyte, is fabricated by various methods such as a ZnO dip-coating, $TiCl_4$ dip-coating, and Ti sputtering. In this study, we tried to fabricate the $TiO_2$ compact layer by the spin-coating method using aqueous $TiCl_4$ solution. The effect of the spin-coating method was checked as compared with conventional dip-coating method. As a result, DSC with a spin-coated compact layer had 33.4% and 6% better efficiency than standard DSC and DSC with a dip-coated compact layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.358-359
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• 2006

In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.