• Membrane and Water Treatment
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• v.4 no.1
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• pp.27-51
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• 2013

During cleaning steps, ultrafiltration membranes are mechanically and chemically stressed. This may result in membrane degradations and failures. In this paper, polysulfone membranes were used to evaluate membrane deteriorations by commercial detergents in static conditions. Ageing of the membrane was simulated by immersing samples in solutions containing commercial detergents with various concentrations, temperatures and times defined by experimental designs. Indeed, an innovative approach in the chemical membranes ageing researches, based on methodological tools, was used in order to achieve significant ageing experiments without using an accelerated ageing protocol. The macroscopic changes were monitored by permeability measurements and mechanical strength tests coupled with a microscopic characterization by ATR-FTIR and HRSEM. The present work details results obtained for three commercial detergents: an alkaline, an acidic and an enzymatic detergent. It was found that the detergents used in the industrial advised conditions (concentration, temperature and time of contact) were not detrimental for membrane properties (permeability and elongation at break) and so for the quality of the produced water. Over the industrial cumulated time of contact, different ageing effects can be observed and compared with the ones induced by NaOCl.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.412-422
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• 2009

This study was conducted to assess exposure to musculoskeletal disorder(MSD) risk factors in hospital personnel who performed non-routinized work tasks. A tool ("PATH-KOSHA" version) was newly revised from PATH(Posture, Activity, Tools and Handling) method and uploaded into a personal digital assistant(PDA). The version was used, on a basis of direct-observation, to collect PATH data at the 2 hospital settings in different regions. Job analysis was performed to get various information (e.g., work and rest time, task type) as well. The data collected were visually checked for data cleaning and stored for future data analysis. A total of 1,992 PATH observations were made for 37 hospital workers. Exposure levels varied across 18 items of the MSD risk factors. The highest percent time spent on non-neutral postures was 53% for wrist deviation, followed by 47%(pinch grip), 35%(trunk posture), 23%(neck posture), and 20%(shoulder/arm posture). The highest percent time spent among hand activity level(HAL) variables was 55% for HAL-cat2 (HAL: 3.3 - <6.7). The percent time of items with respect to both loads with more than 5kg and contact stress was less than 4%. Vibration was not exposed in the study workers. Different aspects were discussed for findings. The study results showed that wrist deviation was highest in percent time spent on awkward posture while HAL-cat2 was highest in hand repetition. The study suggests that distal upper extremity posture and HAL should be primarily addressed and controlled in non-routinized work including the hospital settings.

• Analytical Science and Technology
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• v.5 no.3
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• pp.303-308
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• 1992

Initial reactions of Ti and Si have been studied to examine the surface roughness of titanium silicide. Formation mechanism has been explored with in-situ measurement tools such as AES(Auger electron spectroscopy) and LEED (low energy electron diffraction). One or two monolayers of Ti films have been deposited in ultrahigh vacuum on atomically clean Si(111) substrates. Atomically clean Si substrates which are reconstructed $7{\times}7$ Si(111) have been obtained after in-situ heat cleaning in ultrahigh vacuum. Deposition of the films were monitored by a quartz cuystal oscillator and the Ti films were analyzed with in-situ AES and LEED. The in-situ measurements show that the initial reactions of Ti and Si occur at room temperature and form a disordered layer. At low temperatures($200^{\circ}C{\sim}300^{\circ}C$) intermixing of Ti and Si is detected by AES. Substrate $1{\times}1$ LEED patterns are displayed after $400^{\circ}C$ anneal. This indicates that the disordered layer has transformed to form an ordered surface. The reappearance of the $7{\times}7$ LEED pattern in observed with further high temperature anneals and indicates three dimensional titanium silicide island formation.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.20-20
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• 1998

I Ion beam technology has recently attracted much interest because it has exciting t technological p아:ential for surface analysis, ion beam mixing, surface cleaning and etching i in thin film growth and semiconductor fabrication processes, etc. Es야~cially, ion beam s sputtering has been widely used for sputter depth profiling with x-photoelectron S spectroscopy (XPS) , Auger electron s$\pi$~troscopy(AES), and secondary-ion mass S야i따oscopy(SIMS). However, The problem of surface compositional ch없1ge due to ion b bombardment remains to be understo여 없ld solved. So far sputtering processes have been s studied by s따face an외ysis tools such as XPS, AES, and SIMS which use the sputtering p process again. It would be improbable to measure the modified surface composition profiles a accurately due to ion beam bombardment with surface analysis techniques based on sputter d depth profiling. However, recently Medium energy ion scattering spectroscopy(MEIS) has b been applied to study the sputtering of solid surface at ion bombardment and has been p proved that it has been extremely valuable in probing the surface composition 뻐d s structure nondestructively and quantita디vely with less than 1.0 nm depth resolution. To u understand the sputtering processes of solid surface at ion bombardment, The Molecular D Dynamics(MD) and Monte Carlo(MC) simulation has been used and give an intimate i insight into the sputtering processes of solid surfaces. In this presentation, the sputtering processes of alloys and compound samples at ion b bombardment will be reviewed and the MEIS results for the Ar+ sputter induced altered l layer of the TazOs thin film 뻐dd없nage profiling of Ar+ ion sputt얹"ed Si(100) surface will b be discussed with the results of MD and MC simulation.tion.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.06a
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• pp.3-3
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• 2001

Recently TiN, TiAlN, CrN hardcoatings have adapted many industrial application such as die, mold and cutting tools because of good wear resistant and thermal stability. However, in terms of high speed process, general hard coatings have been limited by oxidation and thermal hardness drop. Especially in the case of PCB drill, high speed cutting and without lubricant process condition have not adapted these coatings until now. Therefore more recently, superhard nanocomposite coating which have superhard and good thermal stability have developed. In previous works, WC-TiAlN new nanocomposite film was investigated by cathodic arc ion plating system. Control of AI concentration, WC-TiAlN multi layer composite coating with controlled microstructure was carried out and provides additional enhancement of mechanical properties as well as oxidation resistance at elevated temperature. It is noted that microhardness ofWC-TiA1N multi layer composite coating increased up to 50 Gpa and got thermal stability about $900^{\circ}C$. In this study WC-TiAlN nanocomposite coating was deposited on PCB drill for enhancement of life time. The parameter was A1 concentration and plasma cleaning time for edge sharpness maintaining. The characteristic of WC-TiAlN film formation and wear behaviors are discussed with data from AlES, XRD, EDS and SEM analysis. Through field test, enhancement of life time for PCB drill was measured.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.310-316
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• 2022

In this study, we compared the microbial reduction effects of drying, hot water, and microwave sterilization in scourers and dishcloths to suggest a most suitable sterilization method. Three scourer types (silver, copper, and mesh) were used, and three dishcloth types (silver, bamboo, and cotton) were used. Drying time dependent reduction in Escherichia coli was high in silver and copper scourers, but minimal bacterial reduction was obtained against Bacillus cereus in all scourers and dishcloths. In scourers, E. coli was not detected after ≥30 s of hot water sterilization at 77℃, and B. cereus was not detected after ≥60 s of hot water sterilization at 100℃. In dishcloths, E. coli was not detected after hot water sterilization at 77℃ for ≥30 s, but B. cereus was detected after hot water sterilization at 100℃ for ≥60 s. In scourers, E. coli was not detected after microwave sterilization at 700 W for 3 min, but B. cereus was detected. In dishcloths, E. coli was not detected after microwave sterilization with 700 W for ≥1 min, but B. cereus was detected in the cotton dishcloth even after sterilization for 3 min. In conclusion, the use of antimicrobial scourers (silver and copper) and dishcloths (silver and bamboo) are not sufficient to reduce the microbial contamination. The guideline provided by the Ministry of Food and Drug Safety suggesting dishcloth sterilization via hot water at 100℃ for 30 s was also found to be insufficient. Based on our research, we suggest that the most effective methods of microbial management are submerging scourers in hot water at 100℃ for ≥1 min, and sterilizing dishcloths for ≥3 min using a 700 W microwave.

• Journal of Distribution Science
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• v.12 no.4
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• pp.11-22
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• 2014

Purpose - The domestic franchise industry has made significant contributions to industry such as investment, employment, and community economy development, facilitating growth potential. The franchise industry provides management knowhow transfer between parent companies and franchisees as per contracts addressing use of business signs, franchisees' independent position, franchisor support, and royalties to be paid to the franchisors. However, many franchisors lack management knowhow and provide insufficient support because of poor control of franchisees and not having a systematic approach to support. This results in dissatisfied franchisees and failure to establish long-term relationships. Few studies have examined relational commitment and/or re-contract intention by support resources between franchisors and franchisees, despite a considerable output of theories and studies of the growth of the franchise industry. The purpose of this study, therefore, was to examine the effects of the ability to provide resources on relational commitments and re-contract intention, and to suggest causal relationships and implications. Research design, data, and methodology - The subject was domestic franchisors registered with the Association of Franchise with more than 50 franchisees. Franchisees under contract for 2 years and considering re-contract of their franchise 2 years later were used. The subjects totaled 300 franchisees in Seoul. A questionnaire survey was used to investigate the subject of franchisees' concessions during the 10 days from November 21, 2013 to November 30, 2013. After excluding 16 surveys with poor answers, 284 responses were finally used. Four areas and 44 questions were used. A nominal scale was used for four common characteristics questions including gender, ages, educational background, and franchise managing time. Questions regarding ability, relational commitment, and re-contract intention made use of a Likert 5-point scale. Data coding and data cleaning were used. SPSS 18.0 was used as follows. First, frequency analysis was done to investigate demographic characteristics. Second, exploratory factor analysis was done to verify validity of testing tools, and Cronbach's α coefficient was used to verify reliability. Third, correlation analysis and multiple regression analysis were done. An exploratory factor analysis was done to verify validity of concepts. A correlation analysis was done to test relationships between the variables, and multiple regression analysis was done to verify franchisor's ability, franchisees' relational commitment, and re-contract intention. Results - The following were the outcomes. First, store operation management, finance operation management, and human resource management affected the calculated bond. Second, store operation management and finance operation management affected the emotional bond. Third, store operation management, finance operation management, human resource management, and marketing management affected the prescriptive bond. Fourth, calculated bond and prescriptive bond had an effect on re-contract intention. Conclusions - As stated above, in franchise management, parent companies' offer and instruction of core competence to their franchisees as an information resource could improve the relational bond by helping them grow together through the resource sharing. Consequently, core competence factors were promoting factors that could improve franchisees' re-contract intention for a long time.

• Journal of Internet Computing and Services
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• v.21 no.4
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• pp.97-107
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• 2020

This study aims to conduct a comprehensive meta-study from the perspective of content analysis to explore trends in Korean academic research on the sharing economy by using the big data analytics. Comprehensive meta-analysis methodology can examine the entire set of research results historically and wholly to illuminate the tendency or properties of the overall research trend. Academic research related to the sharing economy first appeared in the year in which Professor Lawrence Lessig introduced the concept of the sharing economy to the world in 2008, but research began in earnest in 2013. In particular, between 2006 and 2008, research improved dramatically. In order to grasp the overall flow of domestic academic research of trends, 8 years of papers from 2013 to the present have been selected as target analysis papers, focusing on titles, keywords, and abstracts using database of electronic journals. Big data analysis was performed in the order of cleaning, analysis, and visualization of the collected data to derive research trends and insights by year and type of literature. We used Python3.7 and Textom analysis tools for data preprocessing, text mining, and metrics frequency analysis for key word extraction, and N-gram chart, centrality and social network analysis and CONCOR clustering visualization based on UCINET6/NetDraw, Textom program, the keywords clustered into 8 groups were used to derive the typologies of each research trend. The outcomes of this study will provide useful theoretical insights and guideline to future studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.173-179
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• 2020

The purpose of this study was to examine whether chicken-rearing activity is effective on the character, emotion and self-esteem of middle school students, as a pilot study for the development of an animal-assisted education program based on chicken-rearing activity. School was selected as the place where students have experience with raising animals before and no poultry farms were located near the school. The experimental group consisted of 11 students as the chicken-rearing group. The conducted activities were greeting chickens, cleaning henhouse, feeding them, and picking eggs up for five months. Character, emotion and self-esteem scales were used as test tools, and pre-testing and post-testing were conducted to verify the effectiveness of the study. Data collected were analyzed by using SPSS Win 25.0 statistical program. As a result, the character, emotional stability and self-esteem of middle school students who participated in chicken-rearing activity were improved. This study is meaningful in that the chicken-rearing activity proved to be effective for the character, emotion and self-esteem of middle school students and prepared an experimental case study for developing an animal-assisted education program based on chicken-rearing activity. It is expected to be useful as basic data of animal-assisted education for adolescents in school.

• Journal of Distribution Science
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• v.13 no.1
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• pp.105-118
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• 2015

Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusions - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.