• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.7
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• pp.1229-1234
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• 2008

In this work, ultra high-voltage (17 - 50 kV AC), reliable 80 pF mica capacitors for partial discharge system application were investigated. Mica was used as the dielectric of the capacitors. Using the conservative design rule, over 3 individual $50\;{\mu}m$ thick mica sheets with a size of 30mm{\times}35mm were used with lead foils to form a parallel capacitor element and 20 mica sheets were interleaved with lead foils to form a series stack of parallel capacitor element to meet the requirements of the capacitors. The dimensions of the fabricated 80 pF capacitors for 17 kV AC and 50 kV AC were $90\;mm{\times}90\;mm$ and $95\;mm{\times}180\;mm$, respectively. The high-frequency characteristics of the capacitance (C) and dissipation factor (D) of the developed capacitors were measured using a capacitance meter. The developed capacitors exhibited C of 79.5 - 87.5 pF, had D of 0.001% over the frequency ranges of 150 kHz to 50 MHz, had a self-resonant frequency of 65 MHz, and showed results comparable to those measured for the capacitors prepared recently by $Adwel^{Tm}$. The developed capacitors also showed excellent characteristics for thermal shock test and temperature cycling test.

• Journal of Power System Engineering
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• v.5 no.1
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• pp.64-72
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• 2001

According to the regulation of IMO, oil discharge from ships is allowed under 15ppm only and an oil filtering equipment is essential. However, for large ships using heavy fuel oil of over S.G 0.98 and viscosity 380cSt and system oil, it has been in difficulty to process with existing filtering type of oily water separator. A parallel plate type oily water separator which is one of gravity type separators can be used as an assistant equipment for the oil filtering system to meet the present IMO standard of 15 ppm, because it is an efficient method in dealing with a large amount of rich oil with high specific gravity. This work is focused on the fundamental investigation of the performance of the plate type oily water separator by visualization method and PIV(Particle Image Velocimetry) measurement to acquire multi-point velocity data simultaneously. The experimental results showed that the space of the plates acts a significant role in separating process and it was found that an important point to minimize a vortex flow is to flow a large amount of fluid in space of the plates in order to promote the efficiency of separation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.436-437
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• 2006

In this work, impedance Spectroscopic analysis was applied to study the effect of plasma treatment on the surface of indum-tin oxide (ITO) anodes using $O_2$ gas and to model the equivalent circuit for organic light emitting diodes (OLEDs) with the $O_2$ plasma treatment of ITO surface at the anodes. This device with ITO/TPD/Alq3/LiF/Al structure can be modeled as a simple combination of a resistor and a capacitor. The $O_2$ plasma treatment on the surface of ITO shifts the vacuum level of the ITO as a result of which the barrier height for hole injection at the ITO/organic interface is reduced. The impedance spectroscopy measurement of the devices with the $O_2$ plasma treatment on the surface of ITO anodes shows change of values in parallel resistance ($R_p$) and parallel capacitance ($C_p$).

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.183-187
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• 2002

This study researched that the remodeling was executed desirably in the side of deweller's household to the subject of ten apartment housings located in Gwang-ju, Jun-nam province. The study method was used the field study method and used in parallel with participant observation. As a result of the study, first, the problems of remodeling enforcement process are brought about standardized design, bad construction and the difficulty of solution in the defect occurrence. Second, By that request of the household is not reflected, the room except bedroom and the bathroom of inner room are low practical use degree. And wash space, garden space, assistant space of kitchen work were becoming hindrance factor of the residing environment because the use is irrational.

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.53-62
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• 2014

In Korea, in general, separation distance between existing parallel tunnels was set at two to five times as distant as the diameter of the tunnels according to ground conditions. Recently, however, actual applicability of closely spaced parallel tunnels whose distance between tunnel centers was shorter than the diameter has increased due to environmental damages resulting from massive cutting, restriction in purchase of required land, and maintenance of linear continuity. In particular, when the pillar width of tunnel decreases, the safety of pillars affects behaviors of the tunnel and therefore the need for diverse relevant studies has emerged. However, research so far has been largely confined to analysis of behavior characteristics of pillars, or parameters affecting design, and actually applicable and quantitative data have not been presented. Accordingly, in order to present a stability evaluation method which may maximally reflect construction conditions of spots, this study reflected topographical and stratigraphic characteristics of the portal part with the highest closeness between the tunnels, simulated multi-layer conditions with rock mass and complete weathering, and assessed the degree of effect the stability of pillars had on the entire tunnels through numerical analysis according to changes in pillar width by ground strength. This study also presented composite analysis result on ground surface settlement rates, interference volume rates, and average strength to stress and a formula, which may be applicable to actual work, to evaluate safety rates of closely spaced parallel tunnel pillars and minimum pillar width by ground strength based on failure criteria by Hoek-Brown (1980).

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.245-254
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• 2022

This study is a study to empirically verify the mediating effect on college life adaptation and career preparation behavior of college students. The purpose of this study is to empirically analyze the multi-mediated effects of major satisfaction, job stress, and self-directed learning. For this study, 216 university students were enrolled. For the collected data, SPSS Process macro was used. The result is as follows. First, there were multiple parallel mediating effects and multiple serial mediating effects on major satisfaction, job stress, and self-directed learning between college life adaptability and career preparation behavior. Second, the path of simple mediation and double mediation effect was found between college life adaptation and career preparation behavior. Based on the research, the necessity of revitalizing the program for revitalization of teaching activities and industry-academic cooperation activities in the major field and improvement of career preparation behavior and university life adaptation ability and follow-up research were suggested.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.5
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• pp.626-636
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• 2004

The purpose of this study was to show a theoretical system of expressional area, the characteristics and the effects which is applied to fashion illustration by metaphor theory. The theoretical system of expressional area was analyzed by category analysis and 150 fashion illustrations from 1900 to 1999 were analyzed by contents analysis. The results of this study were as follows: Metaphor in fashion illustration was categorized to replacement, parody, heterogeneous combination, surrealism, magnification and reduction of size, optical illusion, juxtaposition and distortion of form. In detail, First, replacement was showed omission of form, non-object color, texture. Second, parody was showed using the part in artistic work, differentiation of original work. Third, heterogeneous combination was showed unreal body combining between animal and plant. Fourth, surrealism was showed creation of object which is impossible to present. Fifth, magnification and reduction of size was showed bizarre magnification of part of body, size of clothing. Sixth, optical illusion was showed ambiguity of object because of creation of new form. Seventh, juxtaposition was showed the parallel of contradicting idea and change of meaning between heterogeneous objects. Eighth, the distortion of form was showed grotesque distortion of part of body and disgusting object.

• Journal of the Korea Safety Management & Science
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• v.24 no.4
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• pp.15-23
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• 2022

This study investigated the effects of job stress, job attitude, and social support on the relationship between client violence and social worker job response. The multi-mediating effect of job stress, job attitude, and social support between client violence and social worker job response was empirically analyzed. 257 social workers in social welfare facilities were analyzed using SPSS. The following conclusions were drawn. First, there was a significant correlation between client violence, job stress, job attitude, social support, and job response variables. Client violence was affecting variables related to social worker job response. Second, job stress, job attitude, and social support had multiple mediating effects. The parallel mediation effect and the serial mediation effect were verified. Third, job attitude was found to be a variable of multiple mediating effects. Fourth, job stress and social support were found to be double mediating effect variables. In response, programs and manuals suitable for the type of social welfare facilities and the policy basis for preparing countermeasures for social workers were limited, and follow-up studies on various variables were suggested.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.237-246
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• 2014

The purpose of this study is to identify the overall occupational safety and health status and the characteristics of the workers engaged in the field of the film and television artists, and to take appropriate measures to prevent industrial accidents, profession and working environment, safety recognition and education, safety activities, accident experience, and job stress survey. Survey using a structured questionnaire is to be used for 302 worker directly interview research. Safety awareness level of himself or herself was "middle level" of 3.1 points. Those of colleagues and the general public were evaluated to be low as 2.8 points and 2.5 points, respectively. During the last 12 months, 4.6% of total workers have received an industrial safety health education for work-related accident or disease. Regarding cases of having experienced work-related accident or having been exposed to work-related disease over the past 1 year, 20.2% of total respondents have experienced accident. 16.2% of total respondents have experienced work-related disease. And the workers are approximately one's own subjective feeling of physical symptoms that have appeared. In addition, the film sector workers in particular occupations men than women have higher job stress. Preventive education for industrial safety is required to be expanded and strengthened. Safety education is urgently required in order to prevent, and to reduce accident. Safety and health guideline is required to be developed and disseminated in order to prevent accident in advance. Finally, the actor and their staff members to reduce the stress, mental health care and education carefully needs to be in parallel. Also, when taking measures to reinforce safe work environment, it needs to be protected.

• The Journal of Bigdata
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• v.7 no.1
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• pp.1-14
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• 2022

The proof-of-work consensus algorithm used by most blockchains is causing a massive waste of computing resources in the form of mining. A useful proof-of-work consensus algorithm has been studied to reduce the waste of computing resources in proof-of-work, but there are still resource waste and mining centralization problems when creating blocks. In this paper, the problem of resource waste in block generation was solved by replacing the relatively inefficient computation process for block generation with distributed artificial intelligence model learning. In addition, by providing fair rewards to nodes participating in the learning process, nodes with weak computing power were motivated to participate, and performance similar to the existing centralized AI learning method was maintained. To show the validity of the proposed methodology, we implemented a blockchain network capable of distributed AI learning and experimented with reward distribution through resource verification, and compared the results of the existing centralized learning method and the blockchain distributed AI learning method. In addition, as a future study, the thesis was concluded by suggesting problems and development directions that may occur when expanding the blockchain main network and artificial intelligence model.