• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2338-2343
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• 2007

The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was proposed, which are composed of data collection, data analysis, improvement action, verification, and implement control. The partition check method for data collection and data analysis was used in the cellular phone module production lines. And this method was evaluated by the variation of yield loss between before and after improvement action. In case that the partition check method was applied, the critical process step was selected and yield loss reduction through improvement actions was observed. From these results, it is concluded that the partition check method is effective solution for particle contamination control in the cleanroom production lines.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.6 s.261
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• pp.522-530
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• 2007

The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was proposed, which are composed of data collection, data analysis, improvement action, verification, and implement control. The partition check method and the composition analysis for data collection and data analysis were respectively used in the main board and the cellular phone module production lines. And these methods were evaluated by the variation of yield loss between before and after improvement action. In case that the partition check method was applied, the critical process step was selected and yield loss reduction through improvement actions was observed. While in case that the composition analysis was applied, the critical sources were selected and yield loss reduction through improvement actions was also investigated. From these results, it is concluded that the partition check and the composition analysis are effective solutions for particle contamination control in the cleanroom production lines.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.153-156
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• 2000

To reduce the maintenance expense, and the possibility of electric outage and accident, we should optimize the outdoor insulation system. And for the optimization, accurate measurement for the degree of contamination with climatic conditions, such as wind, rain, and drought, should be carried. However the classical measuring method, brush wiping, has some problems in the aspect of man power, reliability, and expense. In this paper, we propose two type apparatus, which could detect the degree of contamination on insulators in outdoor insulation system, such as transmission and distribution line insulator and bushing. One use the leakage current, and the other use the oscillating frequency to check the degree of contamination. To avoid the oxidation of electrode AC source, and the low degree of contamination was applied. From the result of this investigation we could get the good relationship between the degree of contamination and the leakage current and oscillating frequency

• Journal of Korean Biological Nursing Science
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• v.21 no.2
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• pp.133-140
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• 2019

Purpose: The purpose of this study was to check the degree of residual microbial contamination after disinfection of reusable suction containers, used in an intensive care unit (ICU) and present basic data for efficient use through cost analysis in comparison to disposable suction containers. Methods: This study was conducted on 32 reusable suction containers used in an ICU on a selected specific day. After disinfection and washing, specimens were collected from the used containers and cultured to check for microbial contamination. Additionally, a comparative narrative study analyzes the cost of using reusable suction containers and disposable suction containers. Data were analyzed with the SPSS WIN 20.0 program using real numbers and percentage ${\chi}^2$-test. Results: As a result of the study, microorganisms were found in all samples where in 30 were gram-positive (62.5%) while 13 were gram-negative (27.1%). Based on level of contamination, microorganisms were less than 10CFU/ml in 18 samples (56.3%); 11-99CFU/ml in six samples (18.8%); and more than 100CFU/ml in eight samples (25%). Cost per day for a reusable suction container was $10,655+{\alpha}$ while cost per day for a disposable suction container was 10,666 won. Conclusion: This study found that reusable suction containers, even after disinfection, accounted for factors of potential infection as well as microbial contamination. So, disposable suction containers are superior in cost-effectiveness and highly efficient for use with infected patients.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.1
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• pp.5-13
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• 2011

This research proposed the space planing methode and diagrams of restaurant kitchens to improve hygiene by analyzing the related contents collected from books and researches in interior design and HACCP (Hazard Analysis and Critical Control Point). HACCP is an effective and scientific hygiene system for food safety in order to prevent cross-contamination from food hazards. Based on the analyses, improvement of food production environments like restaurant kitchens is necessary for food hygiene. The space planing methode of restaurant kitchens to improve hygiene are followings: The circulation planing is that the direction of movement of the food, workers, waste, and dishes should be fractionated and managed for cross-contamination prevention. The space separation planing is that the spaces in the kitchen should be classified and divided into contaminated area and non-contaminated and clean area depending on the degree of cleanliness. The zoning is space arrangement with feed-back process to check the possible points of cross-contamination and correct space arrangement until the possibility of cross-contamination disappear in kitchen. However, if cross-contamination is unavoidable in some points in restaurant kitchens, hygiene facilities such as washing rooms, pass rooms, and double doors with air-shower should be located in order to remove contamination.

• Journal of Mushroom
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• v.10 no.1
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• pp.44-48
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• 2012

In this study, whether Giemsa staining solution can accurately determine bacterial contamination of liquid spawn for Flammulina velutipes in a short period of time was investigated. Giemsa solution staining cells of blood, bone marrow, lymph node, malaria parasites, rickettsia et al. was prepared by dissolving basic methylene azul and methylene blue, and acidic eosine in methyl alcohol-glycerine. Supernatant samples of Flammulina velutipes liquid spawn cultured under explosive aeration were placed on a slide, mixed with Gimesa solution and examined with optical microscope after staining. In 40 to 60 seconds bacterial cells were distinguishable from soybean meal residual and hyphal cell fragments. Thus we conclude that microscopy using Gimesa staining solution is a quick, simple and accurate method for the mushroom growers to effectively use to detect bacterial contamination of the liquid spawn.

• Journal of Korean Academy of Nursing
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• v.14 no.2
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• pp.55-62
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• 1984

This study was performed from september 26th to October 7th 1981 to investigate the contamination problems of Nurse's hands characterized by var-ious nursing functions. A total of 50 nurse's hands were sampled from 5 different wards of H. University Hospital. The samples were cultured for isolation of microorganisms. The results were as follows: 1. Of 50 Nurses 23 were found to be contaminated by 9 species of bacilli such as Non-fermentative gram negative Bacilli, Gram negative bacilli, Oxidase positive, Enterobacter, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter, Staphylococcus epidermidis, Gaffkya tetragens, Bacillus subtilis. 2. The contaminate rates by wards where they have been serving are; 7 (87.5％) of 8 nurses from Intensive care unit, 7(70%) of 10 nurses from general surgery ward, 3(50%) of 6 nurses from neurosurgery ward, 2(20%) of 10 nurses from orthopedic surgery ward, 4(25%) of 10 nurses from medical ward. 3. The contamination rates by the types of clinical service offered are 6(85.7%) of 7 nurses after wound dressing assist 6 (55.3%) of 13 nurses after vital sign check. 4. No statistical significance could he observed as to the between the rates of contamination of nurse's hands with various nursing functions (0.1

• Journal of radiological science and technology
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• v.43 no.1
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• pp.1-7
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• 2020

In this study, the contamination level was measured using an ATP meter using adenosine triphosphate bioluminescent material to find effective infection control to compensate for the disadvantages of the microbial culture method used for hygiene control of ultrasound probe. The convex probes were selected from six ultrasound probe in the hospital, and the samples were taken in real time before and after cleaning to check the contamination of the probe. In order to classify the pollution degree using the APT meter was classified by category. A total of 78 samples were collected from the ultrasound probe. When the pollution levels before and after cleaning were classified by category, 76.6% of the samples were classified into category 3·4 before cleaning, but they decreased to 23.3% after cleaning. 13.3% before cleaning was in category 1, but increased to 43.3% after cleaning. By classifying the pollution level, it was confirmed that the pollution level was significantly reduced by category. Until now, there was no suitable criterion for determining the contamination level by using ATP meter in medical machines where sample area is small and reused. In this study, criteria for each category were set to measure the contamination level of ATP meter suitable for small sample area such as ultrasound probe, so that contamination level could be determined in real time at the site. Therefore, it is considered that hygiene management for ultrasound probe can be more actively performed.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.111-128
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• 1992

According to the increase of population and industrialization, the quality of our drinking water are becoming worse by the contamination of resources, production of THM and other halogenated hydrocarbons during the purifying process, the problem of corroded water supplying pipeline, and the water reservoir tanks, Many people choose groundwater to drink instead of city tap water, but sometimes we get report about groundwater contamination by wastes, swage, septic tank, etc. It is reported that in U. S. over 20% of population are drinking groundwater, but U. S EPA reported the groundwater contamination by pesticides, herbicides, fungicides, fertilizer, and various chemical substances. Craun, et at announced the groundwater contamination by bacteria which are related with poor installation of septic tank. Johnson and Kross mentioned aboutmethemoglobinemia by NO3-N originated from human and animal feces, organic chemicals, and fertilizer, and as the results the infant mortality could be risen. Some scientist also reported the high concentration of metals in groundwaters and some cation and anions, and volatile organic compou nds. Authors investigated 80 groundwaters in urban, agricultural, and industrial area during last 3 month(June - August) to check any drinking water quality parameters are exceeding the standards. The results were as follow. 1, The average value of ammonia nitrate were within the standard, but 11.76% of urban area were exceeded the 10 rpm standard, in agricultural area 42.3175 were exceeded, and in industrial area 20.2% were exceeded the drinking water standard of 10 ppm. the highest concentration was 29.37 ppd in industrial area. 2. The mean value of metals is not exceeded the standard, but there were some groundwater whose Mn value was 0.424 ppm(standard is 0,3 ppm) in urban area, 0.737 rpm in agricultural area, and 5.188 ppm in industrial area. The highest Zn value was 1.221 ppm (standard is 1.0 ppm)was found in industrial area. 3. The percentage of contamination by general bacteria was 8.82% in urban area, 15.38% in agricultural area, and 15.00% in industrial area. Escherichia coil group was also contaminated by 35.29% in urban area, 30.76% in agricultural area, and 30.00% in industrial area. 4, The pH value was within the standard which means there was no influence by acid or alkali chemicals, nor acid rain Through the above results, all the groundwater should be tested to check the safety for drinking water and should make some alternative methods suitable for drink.

• Journal of Korean Public Health Nursing
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• v.12 no.2
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• pp.185-200
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• 1998

It has been contributed to public health that the hospital has multiplied in the aspect of number and has been a large size with development of modern medical science, meanwhile the problem of hospital infection is coming out seriously. Respiratory hospital infection among hospital infections develops, very commonly from patients having taken the operation of intubation or tracheostomy, which results from a big factor that the infection developed from medical appliances used for respiration aids, contamination of solution and infection of medical staff. This study is separated into four steps-the time to use normal saline and distillation water for storaging catheter which are the cause of the infection of solution to store distillation water and catheter, not to say the catheter used when the patient who should get tracheostomy operation takes suction. The purpose of this study is to offer the basic data which are needed to check contamination degree as time goes by and nurse intervention and grope for a new nursing intervention. The target of this study is hospitalized 1D an intensive care unit having 700 sickbeds which is located in IKSAN city and it targeted patients before 7 days passed after an operaion of a tracheostormy. Materials collected were analyzed by SPSS PC+ figures program. The result of this study were as follows ; 1. The gradual contamination levels of the normal saline used In suction are showing that colony increase in proportion to the length of time. 2. while colony increases in normal saline with the lapse of time. distillation water mixed with 5cc of potadine did not show any sign of the formation of colony from its preparation until it was used for 8 hours. 3. Such variables as the period of intubation insertion. the length of hospitalization in I.C.U. the age and the level of contamination of normal saline have no inter-relationship. Therefore. as the length of normal saline used In suction. the contamination level increases with the excelleration of the contamination speed. 4. Regarding the number of suction and the contamination level of the normal saline. We can observe correlation contamination level in the 3 step of suction(mean value:13.4) and the saline which was used for one hours(r=0.702. P=0.00l). four hours(r=0.694. P=0.00l). eight hours(r=0.488. P=0.029). Further we can observe contamination in the 4 step of suction (mean value: 17 .8) well as saline used for eight hours; [for one hours (r=0.64l. P=0.002). four hours (r=0.670. P=0.00l). eight hours (r=0.57 4. P=0.008)]. Thesedays clinics use normal saline by changing it. three times a day. however. the timing of saline change and the current suction methoed should be changed given the one hour used normal saline contamination number 79.850. Regarding the number of suction and the contamination lend of the normal saline.