• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1123-1129
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• 2015

A pair of two-way valves typically is used in automotive washing machines, where the water flow direction is frequently reversed and highly pressurized clean water is sprayed to remove the oil and dirt remaining on machined engine and transmission blocks. Although this valve system has been widely used because of its competitive price, its application is sometimes restricted by surging effects, such as pressure ripples occurring in rapid changes in water flow caused by inaccurate valve control. As an alternative, one three-way reversing valve can replace the valve system because it provides rapid and accurate changes to the water flow direction without any precise control device. However, a cavitation effect occurs because of the complicated bottom plug shape of the valve. In this study, the cavitation index and percent of cavitation (POC) were introduced to numerically evaluate fluid flows via computational fluid dynamics (CFD) analysis. To reduce the cavitation effect generated by the bottom plug, the optimal shape design was carried out through a parametric study, in which a simple computer-aided engineering (CAE) model was applied to avoid time-consuming CFD analysis and difficulties in achieving convergence. The optimal shape design process using full factorial design of experiments (DOEs) and an artificial neural network meta-model yielded the optimal waist and tail length of the bottom plug with a POC value of less than 30%, which meets the requirement of no cavitation occurrence. The optimal waist length, tail length and POC value were found to 6.42 mm, 6.96 mm and 27%, respectively.

• Journal of Biosystems Engineering
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• v.30 no.1 s.108
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• pp.25-31
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• 2005

There are more than three hundred garlic peeling facilities in Korea and most of them use pressurized air for skin peeling operation. One of the major problems of using air for the peeling operation is the occurrence of excessive bruises on the flesh of peeled garlic which causes easy microbial contamination and shortening of the shelf lift. To reduce the occurrence of bruises during the peeling operation, a new type of garlic peeling system was developed which use pressurized water. In this system, high pressure water jets were used to separate garlic bulbs and to peel the skin of garlic cloves. Six commercial systems of this type had been developed and installed at several locations in Korea. The design and performance of the latest system according to three pressure levels were described in this paper. Peeling efficiency of the system was as high as $64.7\%$ in one cycle of peeling operation by three chambers installed in series. Incorporation of a sorting system based on machine vision and re-circulation of unpeeled and partially-peeled garlic enhanced peeling efficiency by additional $30\%$, resulting in total peeling efficiency of the final products of approximately $95\%$. Peeling capacity of the system was over 400 kg per hour.

• Journal of Environmental Health Sciences
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• v.41 no.5
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• pp.314-326
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• 2015

Objectives: This study was conducted to identify the ingredients used in ten consumer product categories and determine hazardous substances among these ingredients. Methods: A total of 542 commercial products in ten consumer product categories were selected. The consumer products were sticker removers, washing machine cleaners, multi-purpose cleaners, mold removers, glass cleaners, chlorinated sanitizers, air conditioner cleaners, disposal cleaners, drain cleaners and disinfectant sprays. The company list was complied from governmental records and a market survey. The respective companies were contacted for a list of ingredients found in the 542 products. Results: The corresponding companies listed 163 ingredients. According to European Union (EU) Directive 67/548/EEC, 38 of the 163 ingredients were classified as dangerous substances. Among these substances, 28 ingredients were hazardous to the skin, 15 were hazardous to the eye, and nine were hazardous if inhaled. Three ingredients were classified as CMR (carcinogenic, mutagenic or toxic for reproduction) substances: liquefied petroleum gases (LPG) with carcinogenicity and mutagenicity, and VM&P naphtha and ligroine with carcinogenicity. Conclusion: Various chemicals, including hazardous substances, were used in consumer products. Risk assessment of consumer products is required in order to protect the population from health risks.

• Journal of the Korean Society of Tobacco Science
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• v.30 no.1
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• pp.14-24
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• 2008

The objective of this study was to determine the effect of smoking conditions on the in vitro toxicological activity of mainstream smoke. The 2R4F reference cigarette was machine-smoked by International Organization for Standardization(ISO) and Canadian Intense(CI) conditions. Smoke was analysed for chemical composition and in vitro toxicity. The cytotoxic potencies of both the total particulate matter(TPM), which were collected in Cambridge filter pad, and gas/vapor phase(GVP), which was bubbled through in phosphate-buffer saline in a gas-washing bottle, were assessed neutral red up take assay with chinese hamster ovary(CHO) cells. The assessment for genotoxicity of TPMs generated under ISO and CI conditions was determined using Salmonella mutagenicity assay and in vitro micronucleus assay. When calculated on an equal TPM basis, in vitro toxicity of TPM obtained under CI condition was decreased compared to TPM generated under ISO condition. The results of chemical composition analyses revealed that the lower toxicological activity under CI condition than that of ISO condition could be explained by the decreased in the contents of phenols, N-nitrosoamines and aromatic amines of TPM on an equal TPM basis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.607-611
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• 2006

There are several methods to obtain structural vibration for analysis of vibro-acoustic noise. First of all, vibration data can be obtained through the structural analysis using finite element method. Although this method has no need to experiment, the analysis result is unreliable when the structure and the vibration source is complex to model exactly. The second method is to measure vibration using a number of sensors. The analyzed vibro-acoustic noise with directly measured data is setting morereliable when the number of data acquisition points is getting larger. However, it requires large amount of time and effort to measure all vibration data on every node especially when the size of vibrating structure is large. The Modal Expansion Method(MEM), which uses mode information and measurement data, has been introduced to compensate their limits. With a relatively small number of measurement data, the reliable structural vibration for vibro-acoustic noise can be obtained using this semi-analysis method. Although MEM gives reliable result, it is restricted by the number of modes and measurement points. In this paper, structural analysis, direct vibration measurement method and MEM are compared using the simple aluminum box model. Furthermore, the washing machine case is also provided as a comparative example. The Laser Doppler Vibrometer(LDV) was used instead of contact type accelerometer to get vibration data.

• Knowledge Management Research
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• v.17 no.2
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• pp.27-50
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• 2016

Korean manufacturing industry have recently faced the catch-up of China in the mass commodity product, such as automotive, display, and smart phone in terms of market as well as technology. Accordingly, discussion on the importance of achieving catch-up in complex product systems (CoPS) has been increasing as a new innovation engine for the industry. In order to achieve successful catch-up of CoPS, we explored emerging technologies of CoPS, which are featured by the characteristics of radical novelty, relatively fast growth and self-sustaining, through the study of emerging technologies of gas turbine for power generation. We found that emerging technologies of the gas turbine are technologies for combustion nozzle and composition of electrical machine for increasing power efficiency, washing technology for particulate matter, cast and material processing technology for enhancing durability from fatigue, cooling technologies from extremely high temperature, interconnection operation technology between renewable energy and the gas turbine for flexibility in power generation, and big data technology for remote monitoring and diagnosis of the gas turbine. We also found that those emerging technologies resulted in technological progress of the gas turbine by converging with other conventional technologies in the gas turbine. It indicates that emerging technologies in CoPS can be appeared on various technological knowledge fields and have complementary relationship with conventional technologies for technology progress of CoPS. It also implies that latecomers need to pursue integrated learning that includes emerging technologies as well as conventional technologies rather than independent learning related to emerging technologies for successful catch-up of CoPS. Our findings provide an important initial theoretical ground for investigating the emerging technologies and their characteristics in CoPS as well as recognizing knowledge management strategy for successful catch-up of latecomers. Our findings also contribute to the policy development of the CoPS from the perspective of innovation strategy and knowledge management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.660-662
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• 2018

With the increasing number of dog markets in modern society, dog owners are deeply rooted in our lives and affecting society. Following this trend, a variety of products have recently been introduced, and it is believed that they have not yet developed much in functional aspect of the post-cleaning system. Due to the busy social life of modern people in everyday life, there is no room to manage dogs in terms of time, cost and environment, which is causing problems. In order to avoid these problems, we are going to develop Eduardo, infrared sensor modules, and automatic pump systems. It is also designed to make it more convenient for users through a laxation pad automatic washing machine.

• Journal of the Korean Home Economics Association
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• v.27 no.4
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• pp.85-103
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• 1989

The purpose of this study is to figure out the urban low-income consumers' present possesion condition of electric appliances, the way of purchasing, shopping scope of groceries and electric appliances, and the shopping scope and information seeking behavior of groceries and electric appliances according to the socioeconomic variables, and the shopping scope of electric appliances according to the way of paying price. For this purpose 129 low-income consumers living in Inchon were interviewed through questionnares. Finally 100 questionnares were analyzed. The first major of this study is that the possesion rates of color television set and refrigerator are comparativelyl high, while those of washing machine, record player and camera are low. In case of electric appliances, consumers usually purchase things on credit and as a shopping place, they usually go to a commercial agent. In case of groceries, they usually buy things for cash, and in case of one price labeled groceries they usually buy things at a supermarket. Second, according to the way of paying price, the shopping scope of some electric appliances is broader in case of purchase for cach than in case of purchase on credit. Third, the shopping scope and information seeking behavior classified by the socioeconomic variables according to the income, age and education. That is as the income and education become higher and the age becomes lower, the shopping scope becomes broader, mass media information source is much more uaed and the frequency of seeking becomes higher. Through this study, I would like to suggest the followings. (1) The problem of low-income consumers is closely connected with the low education level, so it can be solved a bit through consumer education. (2) Especially the consumers' problem is more serious in case of those who are aged and get very low income and education. Therefore special attention is needed to those consumers.

• Journal of the Korean Home Economics Association
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• v.46 no.4
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• pp.47-59
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• 2008

With increasing numbers of immigrant workers in Korea, the supply of socially and culturally acceptable housing has become an important issue. The purpose of this study was to analyze the state of Goryo-in housing and domestic living conditions in metropolitan areas of Korea. This study will present essential information directly relevant to the establishment of practical housing policy for Goryo-in in Korea. Furthermore, data collected and analyzed here will enable comparative investigation with Goryo-ins who live in Russia and Central Asia. Using ethnographic methodologies, we examined 20 Goryo-in households in relation to their usage of domestic space. The following conclusion were established; 1). The most popular L D K(Living Dining Kitchen)type consisted of kitchen plus one or two bedrooms. The majority of households lived in quarters with separated kitchen and living room areas. 2). Most households had a washing machine in the bathroom due to a lack of space, and they regarded the bathtub and the drain hole of the bathroom as very necessary. The Goryo-ins interviewed preferred quarters with separate bathroom and toilet areas, in order to allow simultaneous use. 3). Their most preferred seating style was chairs, while making Kimchi at home was not very popular. 4). All respondents took their shoes off and wore slippers at home, while also indicating a preference for designated shoes space at the entrance to the house. 5) Half of the households had a carpet or mat in the bedroom or living room, both for keeping warm and aesthetic reasons. 6). All households had modified Ondol heating system and demonstrated satisfaction with this. The majority of Goryo-ins interviewed had a different living style compared to households in Russia and Central Asia which were related to less favorable economic conditions in Korea.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.4 no.2
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• pp.229-243
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• 1997

Especially in NICU(Neonatal Intensive Care Unit), handwashing is an important factor in decresing nosocomial infections due to reduced immunity, prematurity and various invasive procedures. The purpose of this study was to investigate the basic characteristics related to handwashing by NICU nurses. It was composed of three parts ; questionnaire survey I (genoral characteristics of handwashing), questionnaire survey II(the awareness degree of handwashing importance) and actual performance. This study was performed from Oct. 8 to 14 in 1994. The results of this study were as follows ; 1. Frequency of handwashing were different by shift of working about 47.1% of the respondents. They were washing most frequently during day-shift about 75% of above. According to self evaluation to handwashing frequency, 64.7% of the respondents said their frequency of handwashing was inadequate, because of being too busy.(45.1%), bothering caused by detergent or disinfectant(17.6%), and too far from handwashing facilities(17.6%). 2. The most common handwashing agent was soap(88.2%), 52.9% of the subjects experienced adverse effects after handwashing ; rough hand(44.5%), dryness(33.3%) All subjects washed their hands with running water, and 70.6% of the subjects washed upto wrist. In duration of handwashing, 52.9% of subjects washed hands 5 to 10 seconds, 29.5% of them did 11 to 15 seconds. 3. 29.4% among subjects had participated to take in the handwashing educational program. About 60% responded they would like to take the course of handwashing if possible. 4. The important nursing activities that need handwashing were chaning of caring ostomy, suctioning, chaning IV dressing site. On the other hand, they responded handwashing was not essential before dealing with omitus, before and after transfering machine, before chaning diaper(stool) 5. Handwashing performance was 61.7%. Among seven nursing activities, suctioning(73.4%) was the highest, the next was dealing with discharge or sampling(71.1%), the lowest was bathing(34.6%). The performance was better after(70.2%) nursing activities that before(52.5%), and day(63.6%) or evening(68.3%) shift than night(56.7%)