• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1599-1602
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• 1994

Recently, failure of COS(cut out switch) due to contamination has been increased. This paper is on the development of the contamination COS. 1 We designed a porcelain insulator of alternate shed for anti-contamination COS. 2 The COS was coated with HVIC(silicone) to improve resistivity to contamination. 3 The FOV characteristics of COS were examined to obtain dry FOV, wet FOV and contamination FOV.

• Water for future
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• v.6 no.2
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• pp.19-29
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• 1973

The progressive contamination of water resulted from man's activity and the use of fertilizers is not restricted only to surface water, but also the shallow groundwater is affected. This type of groundwater contamination is mainly restricted to areas composed of permeable, nonconsolidated sediments forming a shallow aquifer. The chloride and the sulfate resulted from man's activity and the use of fertilizers were measured to study the variations of the groundwater contamination. In general, (1) When water level rises, the rate of groundwater contamination becomes less and when water level declines, the rate of contamination is increased. (2) The highly contaminated season is the early-summer and the less contaminated season is the winter or after rainy season. (3) The groundwater in weathering zone without covering layer. (4) The degree of contamination of wells is increased with the increase of well depth and lowing the water table, because of increasing contaminated water from enlargement of the area of influence of the well.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1306-1313
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• 2012

This paper reports the contamination performance of two distribution arresters (new and used ones) tested under three different contaminant conditions - clean fog, ESDD (equivalent salt deposit density) level (A, B, C, and D), and kaolin contamination conditions, and their leakage current, total leakage current, and component of the resistive leakage current were measured in order to diagnose arrester deterioration. The 3rd harmonics was larger than 5th and 7th ones for the arrester under the clean fog, and as the ESDD contamination level was applied, 5th one became relatively larger than 3rd one. Therefore, these results indicated that the resistive leakage current could be used for the diagnosis of the arresters.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.45-50
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• 1996

The application of HACCP system, which was adopted by Codex Alimentarius Committee for the safe meat and poultry production, is one of the urgent task for competing in the world trade markets. But there have been no useful analytical studies to identify the causes of contamination in the poultry meat processing plants in Korea. This study was conducted to investigate the potential hazards during the operations by the microbiological examination for the poultry meat processing plant (20,000 birds capacity a day) located in Kangwon province. In spite of air contamination of work places, it may not directly affect the surface contamination of poultry meats. But the risk of Campylobacter jejuni/coli contamination was high. The number of total count was decreased about ten times, but remarkable changes of microbial contamination could not be recognized in each procedure during the operations. The washing water was already contaminated as much as $10^{3-6}CFU/ml$ in SPC before the operations. It means that to keep water tanks hygienic is a primary step to prevent the occurrences of microbial contamination. The overflow and recirculation of water in scalding, washing, and chilling was aslo an important factor for a hygienic control. Based on this study, the followings could be regarded as an important factors for hygenic control in the poultry slaughtering plants on a small scale. The temperature of water used for scalding should be constantly maintained on a required temperature, and the overflow rate of 1~1.5 liter per bird. The carcass surface and the body cavity should be washed thoroughly and the cross-contamination due to facilities, workers, and tools should be prevented. The chilling water sholud be maintained under 5$\circ$C of temperature with ice and overflow, and residual chlorine level of 50 ppm.

• Journal of Environmental Health Sciences
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• v.37 no.4
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• pp.323-331
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• 2011

Objective: This study aimed to examine the level of risk perception related to pesticide contamination of food products and associated sociodemographic factors, as well as investigate the association with environmental pollution preventive behaviors. Methods: Based on data from Social Survey conducted in 2008 among a nationally representative sample of the population 15 years or older, we estimated proportions and 95% confidence intervals of the risk perception of pesticide contamination of food products. Logistic regression analyses were used to analyze the effects of sociodemographic status on risk perception. Results: Among respondents, those who feel anxious about the risks of pesticide contamination of domestic food products accounted for 40.4%, whereas the proportion rose to 87.0% with imported food products. These numbers showed that levels of anxiety about the pesticide contamination of imported food products were ranked at the top, and those for domestic products were at the bottom of the list of all environmental pollutants examined in the survey. Significantly related factors to anxiety about pesticide contamination of food products included women, the 40-50 age group, university graduates, married, non-manual employment, having school-aged children, and owning one's own home. The population attempting to prevent environmental pollution showed higher levels of anxiety about pesticide contamination of food products than did those who were not taking such steps. Conclusion: Compared to other forms of environmental pollution, Koreans show the highest levels of anxiety about pesticide contamination of imported food products. Therefore, it is necessary to establish appropriate regulations and transparent risk communication with the public about the safety of imported food.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.627-634
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• 2016

In this paper, an augmented video generation method to evaluate the performance of lane departure warning system is proposed. In our system, the input is a video which have road scene with general clean lane, and the content of output video is the same but the lane is synthesized with contamination image. In order to synthesize the contamination lane image, two approaches were used. One is example-based image synthesis, and the other is background-based image synthesis. Example-based image synthesis is generated in the assumption of the situation that contamination is applied to the lane, and background-based image synthesis is for the situation that the lane is erased due to aging. In this paper, a new contamination pattern generation method using Gaussian function is also proposed in order to produce contamination with various shape and size. The contamination lane video can be generated by shifting synthesized image as lane movement amount obtained empirically. Our experiment showed that the similarity between the generated contamination lane image and real lane image is over 90 %. Futhermore, we can verify the reliability of the video generated from the proposed method through the analysis of the change of lane recognition rate. In other words, the recognition rate based on the video generated from the proposed method is very similar to that of the real contamination lane video.

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.393-400
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• 2017

This study was investigated on pH, heavy metals, oils and solvents in 34 surface soil samples and the samples are collected at two times for 17 farmland sites around 7 industrial areas in Northern Gyeonggi Province. As a result of pH for soil contamination monitoring network, the range of pH showed 4.4~8.4 and average was 6.3. The range of pH for Agricultural land around industrial area was 6.7~7.5 and average indicated 7.1 that mostly showed neutral condition in this area. he average concentrations of Cu, Pb, Ni, As and $Cr^{6+}$ are lower than Korea soil contamination worrisome levels at region 1 and the mean levels of farmland from the soil quality monitoring network. The average concentrations of Zn, Cd and Hg didn't exceed the soil contamination worrisome levels at region 1 but slightly higher than the mean levels of farmland from the soil quality monitoring network. The heavy metal levels of all samples are within Korea soil contamination worrisome levels at region 1. The results showed that the detected heavy metal concentrations ranged from N.D. to ~32.7% of Korea soil contamination worrisome levels at region 1. BTEX, TPH, TCE and PCE were not detected in all samples and thus the farmland around the industrial areas were free from oils and solvents contamination.

• Animal cells and systems
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• v.1 no.2
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• pp.337-340
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• 1997

The purpose of this study is to evaluate whether water soluble chitosan, a natural nontoxic chelator, can reduce fetal contamination of radiostrontium in pregnant mice. Various forms of water soluble chitosans (10% or 1% powder, or 1% solution) were given to pregnant mice before or after contamination of 0.005 uCi/B.W(g) Sr-85. Transplacental transfer of Sr-85 to fetus was $6.8{\pm}2.7%$ of injected dose, when Sr-85 was administered at the 20th day of pregnancy. Fetal radioactivity was significantly reduced when mother mice were treated with water soluble chitosan before contamination of Sr-85. Water soluble chitosans of 10% or 1% powder, or 1% solution significantly reduced fetal retention of Sr-85 to $2.3{\pm}0.7%$, $2.7{\pm}0.8%$, and $2.0{\pm}0.9%$, respectively. However, fetal contamination was not reduced, when water soluble chitosans of 10% or 1% powder, or 1% solution were administered after maternal contamination of Sr-85. From these data we can conclude that water soluble chitosan could reduce fetal contamination of radiostrontium in pregnant mice, when given before the pregnant mice were exposed to radiostrontium.

• Ocean Science Journal
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• v.40 no.1
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• pp.1-10
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• 2005

Variations in species diversity and abundance of polychaete taxocenes that occurred in 1980-1989 under different contamination levels of bottom sediments were studied in three areas of Peter the Great Bay. The most polluted area was shown to be the Golden Horn Inlet where contaminant contents in the bottom sediments exceed the threshold values of negative biota alterations. Amursky Bay is characterized by a moderate level of contamination, while Ussuriysky Bay has the lowest level of contamination. Pollutant contents vary considerably within the same areas and their separate patches are polluted differently. An integral index characterizing the contamination of bottom sediments is proposed. This index is an average grade of the rank value of contaminant contents in sediments. The index was used to compare the contamination level and data on polychaete species diversity and abundance. The highest species diversity of polychaetes is found in the least affected zones. Monotonous decrease of the species number, as well as decrease in the indices of diversity and evenness, is correlated with pollution level increases. Significant growth of the average polychaete biomass and polychaete density is observed in the case of an increase of contamination from low to moderate levels. Conversely, the biomass and abundance of polychaetes decline following an increase in contamination.

• Journal of Environmental Health Sciences
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• v.7 no.1
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• pp.51-57
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• 1981

This Study was carried out to investigate yeast and mold contamination in fermented milk products produced by 9 different domestic manufacturers from October 20. to December 5. 1980 The results obtained in the study were as follows 1) pH values of the products were ranged from pH 3.14 to pH 4.20 and average of sour milk drinks was pH $3.66\pm 0.19$ and fermented milks pH $3.74\pm 0.11$. Therefore the difference of pH average among sour milk drinks and fermented milks was statistically significant. (p<0.01) 2) In case of yeast contamination, yeast was found on all the four producted at the same date. From this result, it seemed that yeast contamination occured during the manufacturing progress. 3) Degree of contamination by the indicator organisms was E. coli positive, 3.7%: over 1,000 yeasts/ml, 14.8% over 10 molds/ml, 0.9%. 4) In the range of over 1,000 yeasts/ml, degree of contamination by yeast was 8.4% in fermented milk and 16.7% in sour milk drink. 5) Yeasts in product C increased to the spoilage number within 5 days and in H increased within 10 days at 5C. At 15$\circ$C, yeast increased to the spoilage number within 15 days in product A.D. 6) It seems that the yeast number of initial contamination should be important than the increase rate as criteria on the fermented Milk products.