• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.56-62
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• 2018

The bus bar is an electrical connection widely used for the power supply of skyscrapers and power distribution and industrial equipment electrical panels in industrial plants. There are various materials to be considered in the design of the bus bar, such as material based on the use environment, the sectional area according to the power capacity, the length of the surface circumference, and the tightening method. Even with a bus bar manufactured to a size of sufficient power capacity in the design, if the actual tightening is incorrect, it may lead to fire due to deterioration. For these reasons, a variety of research on the temperature rise of the electrical contact point has continued. However, the temperature rise of the contacts is a consequence of the result, not a direct cause. In this paper, the influence of contact resistance on the fastening force and the overlapping section of the bus bar are investigated by measuring the change in resistance from building the specimen. A total of eight bus bar specimens were manufactured and measured. Resistance was measured by varying the clamping force and the interval between overlapping sections when the specimens were crossed. We propose a safe power connection model by analyzing the contribution of these factors to the actual contact resistance change.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5861-5869
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• 2014

Existing studies of building exterior materials have focused on the colors or textures of cladding, and in terms of a design planning approach, have focused on the use of the environment and equipment and fire safety topics from an engineering perspective. As a result, little research has been done on performance guidelines for exterior materials, specifically according to the building type. Research into eco-friendly cladding materials is also in the rudimentary stage in a practical sense. In this study, the use of exterior materials over the last ten years in domestic construction was analyzed. The usage status of building exterior materials was evaluated quantitatively by frequency analysis, and its environmental performance is proposed through complex (qualitative + quantitative) analysis. The average value of the exterior material type number used for all analyzed buildings was 2.59. Glass, metal, stone, resin, cement, wood, and clay were used in that order with regard to the usage status. The analysis found that five of the materials satisfied the high efficiency and eco-friendly grading in terms of the four characteristics of an eco-friendly exterior. A list of eight eco-friendly elements was also proposed. The eco-friendly elements and characteristics of the exterior materials were derived to provide basic guidelines for domestic construction companies and design offices.

• Food Science and Preservation
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• v.17 no.2
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• pp.230-235
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• 2010

We investigated the physicochemical quality characteristics of apple juice upon sterilization using hot water, and under various storage conditions. None of sugar content, acidity, or pH differed significantly among various sterilization conditions but chromaticity was considerably reduced in sterilized juice compared with control material. The chromaticity of non-sterilized juice decreased significantly after sterilization compared with material supplemented with vitamin C (0.1%, w/v). Fungi, yeast, and aerobic bacteria were detected in juice sterilized at $65^{\circ}C$ for 10 or 20 min, but no microorganisms were observed in juice sterilized by other procedures. Vitamin C content affected sterilization temperature to a greater extent than sterilization time. When juice was stored at $4^{\circ}C$ or $37^{\circ}C$ for 3 weeks after application of different sterilization conditions, almost no change in acidity, sugar content, or pH was observed, regardless of sterilization mode or storage period. However, chromaticity decreased with longer storage. Vitamin C levels were reduced by higher sterilization temperatures. However, longer storage periods had the greatest effect on reduction of vitamin C levels, which tended toward lower values regardless of differences in sterilization and storage conditions. In sensory evaluation tests, all of taste, color, and overall preference were highest for juice sterilized at $75^{\circ}C$ for 20 min. The ASC value was low at a storage temperature of $4^{\circ}C$ and at high sterilization temperatures, and a long storage period was associated with a greater ASC value. Thus, the quality of apple juice was excellent when juice was hot water-sterilized, with additional vitamin C, at $75^{\circ}C$ for 20 min, followed by storage at $4^{\circ}C$.

• Journal of the Korean earth science society
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• v.36 no.7
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• pp.632-642
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• 2015

Seismograms are composed of 3 characteristics, that is, seismic source, attenuation, and site amplification. Among them, site amplification characteristics should be considered significantly to estimate seismic source and attenuation characteristics with more confidence. This purpose of this study is to estimate the site amplification characteristics at each site using horizontal to vertical (H/V) spectral ratio method. This method, originally proposed by Nakamura (1989), has been applied to study the surface waves in microtremor records. It has been recently extended to the shear wave energy of strong motion and applied to the study of site amplification. This study analyzed the H/V spectral ratio of 6 ground motions respectively using observed data from 4 sites nearby in Yedang Reservoir. And then, site amplification effects at each site, from 3 kinds of seismic energies, that is, S waves, Coda waves energy, and background noise were compared each other. The results suggested that 4 sites showed its own characteristics of site amplification property in specific resonance frequency ranges (YDS: ~11 Hz, YDU: ~4 Hz, YDD: ~7 Hz). Comparison of this study to other studies using different analysis method can give us much more information about dynamic amplification of domestic sites characteristics and site classification.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.215-224
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• 2018

The purpose of the this study was to verify a model for the structural relationships of the behavioral attitude, subjective norm and perceived behavioral control of 119 emergency medical technicians to their safety attitude and safety behavior. A survey was conducted on 373 male and female 119 emergency medical technicians who were working as fire-fighting officers in Seoul, Inheon, Gangwon Province, Daegu, South Chungcheong Province, North Gyeongsang Province and Busan. The collected data were statistically analyzed by SPSS 20.0 and AMOS 16.0. The findings of the study were as follows: First, the behavioral attitude of the 119 emergency medical technicians was found to have affected and safety behavior(t=.32, p<.001). Second, the subjective norm of the 119 emergency medical technicians was found to have exerted an influence on their safety attitude and safety behavior(t=.27, p<.001). Third the perceived behavioral control of the 119 emergency medical technicians was found to have influenced their safety attitude and safety behavior(t=.28, p<.001). Fourth, the safety attitude of the 119 emergency medical technicians was found to have had an impact on their safety behavior(t=.39, p<.001).

• Journal of Oriental Neuropsychiatry
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• v.12 no.1
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• pp.81-95
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• 2001

Though, these days there are increasing many patient of insomnia, there was not considered literatual study on insomnia. So, the result of consideration about cause and process of insomnia from thirty kinds of literatures, are as follows. 1. Early literature like Huangjaenankyung(黃帝內經), Sanghanron(傷寒論) reffered to insomnia as accompanying symptom. on the other hand, Myung(明), Chung(淸)'s literatures reffered to that as chief symptom or distinguished chief symptom from accompanying symptom. 2. There were tendency of deductive expanding of various masters and tendency of induction of simple theory that was based on Huangjaenankyung(黃帝內經). 3. Huangjaenankyung(黃帝內經) showed basic process of the sleep disorder that 'exhausting of Yin and excess of Yang (陰盡陽盛)', protecting energy does not invade Yin portion(陽氣不入於陰). And Huangjaenankyung(黃帝內經) showed cause of insomnia that deficiency of vital energy and blood, imbalanced of spleen and stomach, a fever as a invasion in the outside, lung system's disease. This became a basic cause and process of the sleep disorder in ancient period. 4. Sanghanron(傷寒論) occurred to insomnia as accompanying symptom in progress, remedy of a fever invaded outside, Kumkyeyoriak showed as origination in weakness, fatique, various diseases. Out of that, there is a significance in description of insomnia from some disease like histery or neurosis. 5. Jaebyungwonhuron(諸病源候論), Chunkumbang(千金方), Kukbangseo(局方書.) occured to a fire of heart(心慤) and a deficiency of heart and gall bladder(心膽虛) in defails. Insomnia is caused by agony of seven emotion, delivering of a child, are similar to insomnia is caused by psychologic disorders. Injaesanghanyusu(仁劑傷寒類書) occured to exhausting of Yin and excess of Yang (陰盡陽盛), imbalanced of stomach(胃不和) invasion of coldness(傷寒) are brought a conclusion of assumption of sap(津液耗損) brought about unreturn of yin energy. 6. Manbyunghuechum(萬病回春) in Myung period (明代) made much of portion of phlegm's influence about spiritual function. Kyungakjunsu(景岳全書) valued much of treatment divided according to excess and deficiency. Junginmaekchi(證因脈治) occurred to concept of pyorihesil(表裏虛實), Dongyibokam(東醫寶鑑) synthesised various theories. 7. Hyuljungron(血證論), Byunjungkimun(辨證奇聞), Suksilbirok(石室秘錄) made much of surprisemeni(驚恐) Consideration(思慮), liver's dryness(肝燥) is caused by liver's weakness(肝虛), imbalance of haert -kidney(心腎不交), seven emotion(七情). Especially, ftyujungchijae(類證治載) said that heart, liver, gall-bladder, kidney, surprisment, consideration baought to a conclusion of inbalance of Yang and Yin (陽不交陰). There is a tendency in literature mostly that literature showed separation of insomnia as a chief symptom. 8. These days there are increasing many patient of insomnia. So, it is needed to study about insomnia as a psychologic disease. Saying in conclusion, it is needed that we have to recognize in modern style based on ancient style of cause and process of insomnia. It is regarded to study about insomnia definitely and experimently.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.682-690
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• 2014

In order to improve the thermal stability of wood plastic composites (WPC), thermal degradation behavior of WPC in this study was investigated by the addition of wood flour and fire retardant after hybridization of wood flour and ammonium polyphosphate (APP) into polypropylene (PP) matrix. Thermal degradation behavior of all formulations was analyzed with thermogravimetric analyzer under nitrogen environment at heating rate of $10^{\circ}C/min$. As the thermal degradation temperature of wood flour is lower than that of PP, char layer formed by the wood flour decreases the speed of heat transfer to PP. In addition, the char layer increases the 2nd thermal degradation temperature and decreases the 2nd thermal degradation speed. The WPC treated with APP increases the 1st and 2nd degradation temperatures. In the case of WPC with high loading level of wood flour, the 1st thermal degradation temperature and 2nd thermal degradation rate were increased by the addition of APP, and then the amount of remnants at high temperature was increased by the increase of the APP loading level. In the case of WPC treated with APP, the amount of the remnants at high temperature was increased with the increase of wood flour content from 10 wt% to 50 wt%, indicating that char formation of the APP and wood flour occurred at the same time, resulting in high thermal stability effect by the increase of wood flour content.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.714-722
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• 2014

In the previous study, a variety of wood-based panels was thermally decomposed to manufacture carbonized boards that had been proved to be high abilities of insect and fungi repellence, corrosion and fire resistant, electronic shielding, and formaldehyde adsorption as well as sound absorption performance. Based on the previous study, carbonized medium density fiberboard (c-MDF) was chosen to improve sound absorption performance by holing and sanding process. Three different types of holes (cross shape, square shape, and line) with three different sanding thickness (1, 2, and 3 mm) were applied on c-MDF and then determined sound absorption coefficient (SAC). The control c-MDF without holes had 14% of SAC, however, those c-MDFs with holes had 16.01% (square shape), 15.68% (cross shape), and 14.25% (line) of SAC. Therefore, making holes on the c-MDF did not significantly affect on the SAC. As the degree of sanding increased, the SAC of c-MDF increased approximately 65% on sanding treated c-MDFs (21.5, 21.83, and 19.37%, respectively) compared to the control c-MDF (13%). Based on these results, composite sound absorbing panel was developed with c-MDF and MDF (11 mm). The noise reduction coefficient of composite sound absorbing panel was 0.45 which was high enough to certify as sound absorbing material.

• Science of Emotion and Sensibility
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• v.21 no.1
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• pp.115-128
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• 2018

Understanding the process of spatial perception plays a significant role in the design process as well as in the use of actual spaces. The perception of spatial depth can vary according to the space composition and design even there is no change in the actual size of the space. The properties of 3-dimensional space are its width, height, and depth; however, compared to the perception of spatial width and height, little research and theories exist on spatial depth perception. The reasons may be there less interest lies in the effect of spatial depth perception than that of spaciousness or height of space. This study is an investigation of the process of spatial depth perception using an eye-tracking device with stimuli developed through Computer Graphics. A total of 44 interior design major students participated in the eye tracking experiment; and they looked at three images comprised of an identical room with only changes in the rear wall condition. The results show that a significant difference in the fixation duration per stimulus exists. In addition, a significant difference exists on the fixation duration per stimulus according to the participants' answer of the deepest space. The result of this study can help identify factors for spatial depth perception, validate the assumption on it, and provide knowledge on how to acquire desirable spatial depth by utilizing the research result.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.418-424
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• 2014

The improved thermal stability and anti-oxidation properties of Lyocell fiber were studied based on flame retardant treatment by using NaCl/$H_3PO_4$ solution. The optimized conditions of flame retardant treatment were studied on various maxing ratio of NaCl and $H_3PO_4$ and the mechanism was proposed through experimental results of thermal stability anti-oxidation. The IPDT (integral procedural decomposition temperature), LOI (limited oxygen index) and $E_a$ (activation energy) increased 23, 30 and 24% respectively via flame retardant treatment. It is noted that thermal stability and anti-oxidation improved based on char and carbon layer formation by dehydrogenation and dissociation of C-C bond resulting the hindrance of oxygen and heat energy into polymer resin. The optimized conditions for efficient flame retardant property of Lyocell fiber were provided using NaCl/$H_3PO_4$ solution and the mechanism was also studied based on experimental results such as IDT (initial decomposition temperature), IPDT, LOI and $E_a$.