• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.396-399
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• 2003

4H-SiC un diodes with field limiting rings(FLRs) were fabricated and characterized. The dependences of reverse breakdown voltage on the number of FLRs, the distance between p-base main junction and first FLR, and activation temperatures, were investigated. Al and B ions were implanted and activated at high temperature to form p-base region and p+ region in the n-epilayer. We have obtained up to 1782V of reverse breakdown voltage in the un diode with two FLRs on loom thick epilayer. The differential on-resistances of the fabricated diode are $5.3m{\Omega}cm^2$ at $100A/cm^2$ and $2.7m{\Omega}cm^2$ at $1kA/cm^2$, respectively. All pn diodes with FLRs have higher avalanche breakdown voltages than that of diode without an FLR. Regardless of the activation temperature, the un diode with a FLR located 5um apart from main junction has the highest mean breakdown voltage around 1600V among the diodes with one ring. On the other hand, the pn diode with two rings showed different behavior with activation temperature. It reveals that high voltage SiC pn diodes with low on-resistance can be fabricated by using the FLR edge termination.

• Nuclear Engineering and Technology
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• 제48권2호
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• pp.525-532
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• 2016

High-energy linear accelerators are increasingly used in the medical field. However, the unwanted photo-neutrons can also be contributed to the dose delivered to the patients during their treatments. In this study, neutron fluxes were measured in a solid water phantom placed at the isocenter 1-m distance from the head of an18-MV linac using the foil activation method. The produced activities were measured with a calibrated well-type Ge detector. From the measured fluxes, the total neutron fluence was found to be $(1.17{\pm}0.06){\times}10^7n/cm^2$ per Gy at the phantom surface in a $20{\times}20cm^2$ X-ray field size. The maximum photo-neutron dose was measured to be $0.67{\pm}0.04$ mSv/Gy at $d_{max}=5cm$ depth in the phantom at isocenter. The present results are compared with those obtained for different field sizes of $10{\times}10cm^2$, $15{\times}15cm^2$, and $20{\times}20cm^2$ from 10-, 15-, and 18-MV linacs. Additionally, ambient neutron dose equivalents were determined at different locations in the room and they were found to be negligibly low. The results indicate that the photo-neutron dose at the patient position is not a negligible fraction of the therapeutic photon dose. Thus, there is a need for reduction of the contaminated neutron dose by taking some additional measures, for instance, neutron absorbing-protective materials might be used as aprons during the treatment.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권6호
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• pp.328-333
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• 2006

All the plants on earth live under an electric and magnetic field because the earth is a magnet and there is an electric field between the charged cloud and the ground. It has been reported that electromagnetic fields influence both the activation of ions and polarization of dipoles in living cells of seeds and plants, though the mechanism of these actions is still poorly understood. In this paper, the effects of the electric and magnetic fields and exposure times to the germination of several vegetable seeds and its early growth have been investigated experimentally to find out the feasibility of a plant factory for mass production of clean and unpolluted vegetables. The germination rate and the growth rate of some seeds under the fields exposed were analysed and compared with those of unexposed ones. It is found that the germination rate and its early growth rate of exposed seeds under the fields were accelerated about 1.1-1.4 and 1.7-2.2 times in maximum compared with those of unexposed ones. But, however, an inhibitory effect on germination and plant early growth were shown in the case of the higher electric and magnetic fields.

• The Korean Journal of Physiology
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• 제23권2호
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• pp.409-420
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• 1989

Extracellular recordings were made from the spinal neurons in the lumbar enlargement of 16 cats before and during electrical stimulation of the radial nerve ipsilaterally and contralaterally. Only neurons activated by remote nerve stimulation (RNS) were included in sample. All the cell classes of spinal neurons which received afferents message from the skin and/or muscles were activated by RNS except LT cells. Approximately three quaters of cells activated by RNS had an inhibitory receptive field (RF) on the ipsilateral hindlimb and two thirds of RNS-activated neurons showed spontaneous activity. The most of these RNS-activated cells seemed to be in deep dorsal horn and in ventral horn as well. Stimulation of contralateral radial nerve produced activation of spinal neurons almost same degree as by ipsilateral nerve stimulation. The optimal stimulation parameters of radial nerve for activation of spinal cells were 5Hz-0.5 msec-2V while threshold stimulus for activation was approximately 0.18 V. Following close intra-arterial injection of $K^+$ ion excitability of RNS-activated neuron was increased in 4 of 8 cells whereas it was decreased in 2 of 8 cells. The results indicate that there are some spinal neurons in the lumbar enlargement of cats that can be activated by forelimb afferent $(A{\beta}\;&\;A{\delta})$ inputs.

• 한국건축시공학회지
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• 제7권4호
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• pp.93-99
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• 2007

Highly advanced technologies are being adopted into the domestic construction industry in accordance with rapidly changing global construction industry in the 21st century. Value Engineering methodologies have often been discussed but not yet settled in the country. This research, therefore, aims to provide a useful guide to utilizing design Value Engineering in Build Transfer Lease. 1. Questionnaires had been conducted, answered by those in the field. 2. Questionnaires were in regard to the obstacles in the application of design Value Engineering and activation schemes. 3. Five standards were provided to be chosen according to the degree of influence from each factor, whose answers were technically analyzed by a statistical program afterward. 4. Four obstacles classified in this method were approached systematically to analyze the problems. 5. Efficient Activation schemes have been suggested after various analyses in a variety of aspects.

• 동굴
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• 제75호
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• pp.55-64
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• 2006

The extension of development and originality of the ability which is various leads and studying voluntary character and the ability back the education which it considers actively it raises and the infield it does. With activation plan of cave resources home page of Speleological Society of Korean like home page of Speleological Society of Japan cave crane information, caving information, cave Q/A, cave publication, the relation site back the possibility of seeing information regarding the cave which is various in order to be, it reorganizes. The possibility of coming in contact in order to be, various branch information also the general rain specialist regarding the cave resources. Currently the Possibility of seeing the various branch data for the application of the cave resources at any time it is, home page of Speleological Society of Korean the possibility of doing to lead in order to be, it proposes the plan. From one person it will be able to study the data regarding the cave of various field in order, all curricular materials regarding the cave resources the educational program which leads a home page about under developing it proposes the activation plan of the cave resources.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년 춘계학술발표대회 논문집
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• pp.268-272
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• 2009

The program of public facilities are essential of resident life, and these programs affect quality of life and community activation. The purpose of this study is to analyze the present condition of the program of public facilities and residents' need of program in Yanglim-Dong, Gwangju. In this study, Field survey and questionnaire survey are used for data collection. The results of this study are showed as follows: First, most of the public facilities' programs are composed of educational and welfare program and program for teenager, young people and middle-age. Second, most of the residents prefer to program for culture and sport. Third, most of the residents want to join in one or two every weeks and the time zone of p.m..

• 한국안전학회지
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• 제29권2호
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• pp.98-105
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• 2014

Biosafety has become quite sensitive issues according to dramatic development of biotechnology and LMO(Living Modifying Organism) is one of the key issue in biosafety. This study is an exploratory research for investigating the activation strategy of biosafety training management in LMO research field. Based on the survey data, main results are derived through various statistical analysis methodology such as descriptive analysis, factor analysis, reliability analysis, analysis of variance and regression analysis. According to the analysis results, some activation strategies are required to reach the target such as extension of specialized biosafety training program, enhancement of safety consciousness from the undergraduate courses, introduction of appropriate safety regulations, unification of safety management and establishment of safety management system.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.91.2-91.2
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• 2012

The TiB2-reinforced iron matrix nanocomposite (Fe-TiB2) was in-situ fabricated from titanium hydride (TiH2) and iron boride (FeB) powders by a simple and cost-effective process that combines the mechanical activation (MA) and a subsequent heat treatment (HT). Effect of milling factors and synthesized temperatures on the formation of the nanocomposite were presented and discussed. A differential thermal analyser (DSC-TG) was employed for examination of thermal behavior of MAed powders. Phases of the nanocomposite were confirmed by X-ray diffraction analysis (XRD). The morphologies and microstructure of nanocomposite were investigated by field emission-scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS). Phase composition and distribution were analyzed by electron probe X-ray microanalysis (EPMA). Results showed that TiB2 particles formed in nanoscale were uniformly distributed in alloyed Fe matrix.

• 한국약용작물학회지
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• 제18권6호
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• pp.398-404
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• 2010

Complementary and alternative medicines are considered as a promising research field to develop new therapies for various allergic diseases. In this study, we investigated the anti-allergic effect of Agrimonia pilosa Ledeb (AP) by using passive cutaneous anaphylaxis in mice and its mechanism of action in mast cells. The extract of AP reversibly inhibited degranulation in RBL-2H3 cells and bone marrow-derived mast cells (BMMCs). AP also suppressed the passive cutaneous anaphylaxis inducing by IgE and antigen (Ag) in a dose-dependent manner. In the study to find its mechanism of action, AP inhibited the phosphorylation of Syk kinase, a pivotal protein which is regulated by Src-family kinase for activation of mast cells. In addition, AP also suppressed activation of Akt and Erk1/2 that are critical for the production of cytokines in mast cells. The results strongly suggest that AP exerts anti-allergic activity in vitro and in vivo through the inhibition of activation of Syk in mast cells.