• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.530-539
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• 1997

This study was conducted to assess the health risk on the volatile organic compounds such as toluene, xylene, and styrene in painting workplace. It was monitored through personal air sampling during working time in selected 5 workplaces and analysed using gas chromatography. For the settlement of exposure situation, there were regarded working conditions such as working hours, yearly working days, and working years. Also, Monte-Carlo simulation was used for the induction of hazard index using toxicity value from IRIS(Integrated risk information system) database. The results of risk assessment were summarized as follows. 1. The air concentration of toluene was $7.096{\pm}15,644ppm,\;2.586{\pm}4.275ppm\;for\;xylene,\;1.914{\pm}5.320ppm$ for styrene in blast painting workplaces. The level of toluene was different significantly compared with the level of xylene and styrene. 2. Computated chronic daily intake values of 95th percentile on toluene, xylene and styrene treated by Monte-Carlo simulation were 9.616, 3.567, 2.782 mg/kg/day, respectively. 3. Computated hazard index values of 75th percentile on toluene, xylene and styrene treated by Monte-Carlo simulation were 3.5, 1.0 and 1.6, respectively. Adverse health effects on the toluene, xylene and styrene would be expected by working exposure in selected 5 workplaces since the hazard indices of three compounds were exceeded 1 in the surroundings of 75th percentile though having the low emerged frequency.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.7
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• pp.402-408
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• 2009

In this paper, the effects of ventilation and humidification on thermal comfort and indoor air quality(IAQ) were evaluated in a classroom when a heat pump system was operated in winter. Thermal comfort parameters, such as temperature, relative humidity, globe temperature and air velocity, were measured at 9 points in the classroom. The concentration of $CO_2$ and total suspended particles(TSP) in the classroom were measured in order to analyze IAQ. Temperature distribution in the classroom was decreased by $2{\sim}5^{\circ}C$ when the ventilation system and the humidifier were operated. When the relative humidity was adjusted to 60% by operating the humidifier and the ventilation system, the predicted mean vote(PMV) in the classroom was within the comfortable range of $-0.5{\sim}0.5$. When the ventilation system was operated, the average concentration of $CO_2$ and TSP were decreased by 645 ppm and 0.17 $mg/m^3$, respectively. This paper suggests the humidification and ventilation conditions to maintain the comfortable environment in the school classroom in winter experimentally.

• Archives of Plastic Surgery
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• v.48 no.6
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• pp.660-669
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• 2021

Background The demand for aesthetic procedures continues to grow globally, particularly in East Asian countries. The popularity of specific aesthetic procedures varies, however, depending on the particular East Asian geographical region being studied. This study aimed to evaluate the experiences of and attitudes toward aesthetic procedures in five East Asian countries/regions, including China, Japan, South Korea, Hong Kong, and Taiwan. Methods To recruit participants, an online questionnaire was designed and distributed on social media networks between May 2015 and March 2016. The statistical analysis was conducted using SPSS software, version 22.0. Results A total of 3,088 people responded (approximately 600 in each country/region). Of these, 940 participants (47.8%) responded that they had experienced at least one aesthetic procedure in the past. Taiwan had the highest number of participants who had experienced at least one procedure (264/940, 41%), with primarily non-surgical experiences. Only in South Korea did surgical cosmetic experiences exceed non-surgical cosmetic experiences (55.9% vs. 44.1%). The popularity of particular procedures and the motivation for undergoing aesthetic procedures varied by country. Conclusions The popularity of aesthetic procedures continues to evolve. Similar trends were observed across the East Asian regions; however, each country had its unique demands and preferences. The information provided by this study can help aesthetic plastic surgeons further understand the patients in their corresponding region, customize their practice, and develop the requisite skills.

• Journal of the Korea Society of Computer and Information
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• v.26 no.8
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• pp.229-237
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• 2021

This paper aims to study the using motivation and influencing factors of Chinese users' participation in live stream shopping through theoretical and empirical analysis, so as to evaluate the change in users' needs and improve marketing strategies. In doing so, I conducted a questionnaire survey for Chinese live stream shopping users and collected the required data. For empirical analysis, I used SPSS and AMOS software to carry out descriptive analysis, reliability and validity analysis and structural equation model analysis (SEM) to test the hypothesis. The results of the analysis showed that core competency and brand personality of the short video industry have a significant impact on user and customer perceived value, thus influencing users' using motivation. That is, users do not blindly follow live stream shopping but make their active choice. Therefore, it is suggested that live stream shopping platform should strengthen the e-commerce attributes and eradicate "the sense of false satisfaction", in order to achieve the effective communication of information. On the other hand, to stimulate the purchase motivation of users, the brand should build up its personality, and enhance user and customer perceived value in cyber marketing.

• The Korea Journal of Herbology
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• v.24 no.1
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• pp.133-139
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• 2009

Objectives : This study was designed to investigate the effects of alcoholic fermentation extract from ovary and rind of pear on human skin. Methods : We investigated the effects of samples on human skin in terms of clinical trial. 32 of healthy volunteers, who lived in mokpo participated in clinical trial. Effects of sample on hygroscopicity and water-holding capacity were investigated. Sebum, moisture, scabrousness and desquamation were also investigated. Facial massages were conducted 8 times in each volunteers. Results : Single treatment group showed elevated levels of hygroscopicity (Normal : 106.4$\pm$2.1%, vs Pear : 114.1$\pm$6.2) and water-holding capacity (Normal : 87.1$\pm$4.4%, vs Pear : 96.2$\pm$1.3) on forearm of 16 volunteers respectively. In addition, massage group using sample showed elevated moisture (Control : 3.8$\pm$5.8%, vs Sample : 15.2$\pm$4.7%) and lowered scabrousness levels (Control : -12.3$\pm$4.4%, vs Sample : -22.0$\pm$5.2%) significantly. However, the levels of sebum did not affected by sample. Conclusions : These result suggest that alcoholic fermentation extract from ovary and rind of pear has moisturizing effect on human skin.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.206-215
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• 2022

For a long time, traditional culture has been regarded as one of the sources of the inspiration, method and language of Chinese writing. In this article, we studied the medium- and long-term impact of a traditional Chinese culture seminar attended by college students on the output of creative writing. The seminar included traditional Chinese philosophy, history, literature, art, etc. It spanned three years (22 months) and held lectures lasting for approximately two hours once a week. The subjects of the prospective cohort study included 130 first-year college students who participated in the seminar and 130 controls. From September 2016 to June 2018, 72 lectures were held. We measured the creative writing output from the first lecture (September 2016) to December 2021 (64 months in total), including novels, essays, poems, and plays. Two indicators, the total number of words (TNW) and the quality of yield (QY), were evaluated by a 15-member panel. Although the TNW and QY of the participants and their controls were similar before the seminar, we found that the participants have higher TNW and QY than the controls after participating in the seminar. The difference in TNW became significant after month 51 (p<0.05), and the difference in QY became significant after month 46 (p<0.05). After these dates, the differences stabilized. In addition, text analysis indicates that by month 64, traditional cultural elements in the works of the participating group had a higher frequency (p<0.001). The research shows that the traditional culture seminar not only enhanced the yield of college students' creative writing but also improved the quality of their work. The traditional cultural elements enriched the works of the seminar participants.

• Proceedings of the Technology Innovation Conference
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• 1997.07a
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• pp.222-223
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• 1997

By analyzing the successful innovation case of potato microtuber mass production technology, a representative case of technology-push type creative innovation in an imitation oriented research culture, this paper attempts to figure out conceptual model of creative innovation that is initiated by the public laboratories in catching-up country, Stages of creative innovation can be divided into the internal R&D stage and the external commercialization stage. Success of the internal R&D stage depended on autonomy to secure creative research idea and commitment of individual researchers. Psychological pressure evoked from sportlights of mass media and commitment of sponsor increased the intensity of research efforts of the researcher Recognition of research problem and its significance was intensified by site visits of agricultural fields, and the recognized higher impacts of expected research results and knowledge creation achieved were a fundamental source of self-motivation. In the stage of commercialization stage, various legal, socio-economic, and psychological barriers were confronted. In a catching-up country lacking of experiences of creative innovation, creative innovation process can be regarded as a barrier elimination and cultural revolution process. Among the barriers, psychological refusal of farmers to corn-sized potato seeds was critical, which finally enforced to further researches to enlarge the size of potato seeds. In addition, the researcher has concentrated his research efforts in one specialized research area by getting a series of similar research project funds rather than diversification. It was lucky for him to have a chance to carry out a series of similar researches in one research area during the last 10 years. In getting research funds from government and private companies continuously in one research area, both internal and external promoters played significant roles.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.923-931
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• 2005

A study was carried out to identify the major causes of sediments pollution in the Paldang Lake in the vicinity of Gyeongan river. Samples from 40 sites were collected and analyzed to characterize the regional distributions of grain size, organic matter contents, and concentrations of T-N, T-P and heavy metals. contaminations. The mean grain size(Mz) ranged from sand type(Mz, $1{\sim}3\;{\phi}$) where Bukhan River and Namhan River converges at a high flow rate to silt type(Mz, $5{\sim}10\;{\phi}$) at the downstream of Gyeongancheon and Paldang lake, reflecting the water circulation in the area. Except sampling point St. 36 near the wetland, the determination coefficient($r^2$) of Mz and organic matter(LOI) was 0.88, showing that more organic matters are concentrated inside finer sediments. The concentrations of T-N and T-P in sediments were higher in the area at which Mz and organic matters are also higher. High concentrations of T-P analyzed in the sediments, ranging from $216{\sim}1,623\;{\mu}g/g$ (Avg. $769\;{\mu}g/g$) could be considered as a critical level. Adsorbed-P and NAI-P, which are easily released to the surrounding environments when physico-chemical characteristics of sediments are changed, was found to be around 20%, which was showed by the result of fractionated-P. Moreover, Principle Component Analysis(PCA), showed that high concentrations of T-N, T-P, organophilic metals (Cd, Cu, Pb, Zn) are distributed in the areas where high organic matter contents and fine grain-sized sediments are found. However, results of $I'_{geo}$ (Geoaccumulation Index) that considers the grain size of sediments showed that heavy metal concentrations in the lake was low enough to be considered as Class 1 indicating the relative degree of pollution was less than zero.

• The Journal of Korean Society for School & Community Health Education
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• v.12 no.3
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• pp.65-87
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• 2011

Objectives: The purpose of this study was to perform basic study on environmental and respiratory diseases in Ulsan and vicinities. Also, this study evaluated the actual state of environmental disease and health education at middle and high schools in Ulsan and surroundings. Methods: For this study, we conducted a survey on the health of the general public, environmental effects, and investigated the characteristics of environmental disease, health and hygiene education, etc. The populations of this study were middle and high school students in Ulsan, Korea. This study investigated the knowledge of environmental disease and health education at schools in Ulsan and vicinities from November 2009 to December 2009. All statistical calculations were performed with Statistical Package for Social Sciences (SPSS) for Windows, and gained the following results by implementing Frequency Analysis, Cross-tabulation Analysis and ANOVA. Results: As more and more environmental diseases are increased, the interest of the people has been increasing on this. The incidence rates of asthma and atopy were represented the top 25% of the country in Korea. The source of heavy metal, PAHs and VOCs in Ulsan includes the Petrochemical Complex at Nam-gu and Ulju-gun, the Nonferrous Metal Industrial Complex at Onsan-eup, Ulju-gun, and the Heavy Industrial Complex at Dong-gu and Buk-gu. Especially, there are a number of fossil fuel combustion facilities such as waste incineration plants and boilers at Nam-gu and the Onsan Industrial Complex. It may help greatly to investigate the characteristics of environmental pollutants such as environmental air pollutant and indoor contaminant to better manage the local student's health. Conclusions: It has been revealed that the hazardous chemicals and environmental contaminants are main substances of cause for asthma, atopy, dermatitis, and allergy disease. Therefore, through with collecting basic data such as environmental disease of inhabitants, health education, conscious and knowledgeable level in parents of students and students, We have to exert to improve knowledge and prevention with health life in school through development of health education program systematically for preventing of environmental disease.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.135.1-135.1
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• 2010

최근 고온에서 사용 가능한 PEMFC용 고분자전해질 막 개발에 대한 연구가 활발히 진행되고 있다. PEMFC가 고온에서 작동하게 되면 높은 성능과 많은 장점을 갖게 된다. PEMFC를 $100^{\circ}C$ 이상에서 운전하게 될 경우 백금 전극 반응을 향상시켜 고가의 백금 촉매 양을 줄일 수 있게 되고, 수소연료 속에 미량 포함된 CO에 의한 촉매표면 피독현상에 대한 내구성을 높일 수 있어 저 순도 수소연료 사용이 가능해 진다. 또한 가습장치와 수소 연료 개질장치의 부피를 줄일 수 있게 되어 전체적인 PEMFC 시스템이 단순화 된다. 현재 연료전지용 고분자 전해질막으로 DuPont사의 과-불소계 고분자 전해질막인 Nafion$^{(R)}$이 가장 널리 사용되고 있다. Nafion$^{(R)}$은 유연한 분자구조 안에 소수성이 강한 주사슬과 친수성을 나타내는 술폰산이 결합된 곁사슬이 존재하여 술폰화 곁사슬의 클러스터 둘레에는 친수성 영역이 형성이 되기때문에 소수/친수 상 분리가 잘되어 이온 클러스터 형성이 용이하지만 제조비용이 높은 단점을 갖고 있다. 특히, 전해질 막내에서 Bronsted base 역할을 하는 물에 의해 이온전도가 이루어지기 때문에 고온에서는 수분증발로 인해 성능이 급격히 감소된다. 따라서, 본 연구에서는 고온 저가습 조건에서 운전이 가능하고 Nafion이 갖는 문제점을 해결하고자, 내열특성이 뛰어나며 높은 수소이온 전도도 학보가 용이한 Sulfonated Poly(aryl ether)sulfone(SPAES) 고분자 전해질에, 고온에서도 수화성이 유지될 수 있도록 지르코니아를 황산화한 sulfated zirconia(s-$ZrO_2$)를 함침하여 복합 고분자전해질막을 제조하여 고온 저가습 조건에서의 수소이온 전도 특성에 관한 연구를 수행하였다. 개발된 막의 물리/화학적 특성은 water content(Wup%), 이온교환 용량(IEC, meq $g^{-1}$), 수소이온전도도(s $cm^{-1}$) 열 중량 분석(TGA), X선 회절분석(XRD) 등을 통하여 분석 및 관찰하였다. 내화학 및 열적 특성분석 결과, 황산화 반응공정으로 $ZrO_2$에 술폰산기가 안정적으로 결합하고 있음이 관찰되었으며, 본 연구에서 개발된 유 무기 복합막이 $250^{\circ}C$이상 열적안정성을 확보하고 있는 것으로 판단되었다. $100^{\circ}C$ 이하의 저온 영역에서, 일정 비율의 s-$ZrO_2$/SPAES막에서 이온교환용량(IEC)이 순수 SPAES 막보다 낮음에도 불구하고, water uptake가 증가함과 동시에 수소이온 전도도가 향상된 것을 관찰하였다. 또한, 고온에서는 수소이온이 자유롭게 이동할 수 있는 water channel을 형성하는 free water는 증발 하지만 s-$ZrO_2$와 SPAES의 술폰산기 사이에 강력하게 결합하고 있는 bound Water는 $100^{\circ}C$ 이상의 고온 영역에서도 존재하여, 비록 무가습 조건에서도 일정 비율의 s-$ZrO_2$/SPAES50 전해질 막의 경우, 높은 전도도를 나타냄을 관찰할 수 있었다. 따라서 본 연구를 통해 저가습 고온 적용을 목적으로 개발된 s-$ZrO_2$/SPAES50막은 우수한 내열 특성을 나타냄과 동시에 저가습 고온 영역($120^{\circ}C$, $50RH{\downarrow}$)에서 높은 수소이온 전도도를 유지하여, 고온 저가습 연료전지 운전에 적합할 것으로 사료된다.