• Animal Bioscience
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• v.34 no.6
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• pp.1070-1077
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• 2021

Objective: An experiment was conducted to determine the appropriate fasting time prior to slaughter for broilers in floor-feed and scatter-feed mode. Methods: On 21 d since hatching, 120 Arbor Acres broilers were divided into floor-feed and scatter-feed groups, chicks from each group were further assigned to feed withdrawal treatments for 0, 4, 6, 8, and 10 h. Some resultant indicators such as carcass contamination, body weight loss, meat quality of 54-day-old broilers were measured. Results: It appears that longer feed withdrawal increased weight loss, lightness, drop loss of meat but reduced pH. A significant higher weight loss and lightness for both floor-feed and scatter-feed chicks coincided after 6 to 10 h feed withdrawal (p<0.05). pH for breast muscle at 45 min postmortem reduced when chicks of scatter-feed were fasted 6 and 10 h, while the reduction of floor-feed group occurred only in 10 h (p<0.05). A noticeable effect of feed withdrawal on drop loss occurred after 10 h fasting in scatter-feed of which drop loss were significantly higher than that for other groups including control (p<0.05). The change of contamination propensity revealed that 6 to 10 h fasting significantly reduced the likelihood of carcass contamination under both floor-feed and scatter-feed (p<0.05). Net weights of intestinal contents for gizzard were significantly reduced after feed deprived for 10 h in floor-feed and 6 and 10 h in scatter-feed (p<0.05). The decrease for whole intestine occurred after floor-feed broilers have been without feed for more than 4 h, scatter-feed broilers for more than 8 h (p<0.05). Conclusion: On the premise that poultry product properties and welfare were not significantly damaged, proper fasting time could reduce carcass contamination. Current data implied that 6 h fasting was recommendable for both floor and scatter feed pre-slaughter broilers.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.727-740
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• 2018

The media in the undersaturated zone is defined as the uppermost layer of the water table at which the groundwater is unsaturated or saturated discontinuously. The properties of the unsaturated zone can affect the reduction of contaminants that flow from the lower part of soil to the water table. In recent, there have been problems in evaluating groundwater contaminations vulnerability because weighted value for permeability is given, regardless of anisotropy and heterogeneity in the unsaturated media. Geological media have various ranges of permeability. When applying the weighted value, representative of permeability for grain sizes standardized, to construction of contamination vulnerability, it will produce more exaggerated result than the case that considers unsaturated geological properties. In this study, we performed laboratory column tests considering two sets of the unsaturated layers in order to investigate the permeability in anisotropic unsaturated zone with anisotropy. On the basis of the tests, average permeability coefficients were calculated considering the properties of unsaturated media obtained from drill cores in the field. The final contamination vulnerability map constructed shows that the contamination vulnerability map applying the properties of geological media of the unsaturated zone coincides much better with the results measured in the field, compared to the case of contamination vulnerability considering the weighted value in the unsaturated zone.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.331-341
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• 2023

When creating a soil contamination map using geostatistical techniques, there are various sources that can affect prediction errors. In this study, a grid-based soil contamination map was created from the sampling data of heavy metal concentrations in soil in abandoned mine areas using Ordinary Kriging. Five factors that were judged to affect the prediction error of the soil contamination map were selected, and the variation of the root mean squared error (RMSE) between the predicted value and the actual value was analyzed based on the Leave-one-out technique. Then, using a machine learning algorithm, derived the top three factors affecting the RMSE. As a result, it was analyzed that Variogram Model, Minimum Neighbors, and Anisotropy factors have the largest impact on RMSE in the Standard interpolation. For the variogram models, the Spherical model showed the lowest RMSE, while the Minimum Neighbors had the lowest value at 3 and then increased as the value increased. In the case of Anisotropy, it was found to be more appropriate not to consider anisotropy. In this study, through the combined use of geostatistics and machine learning, it was possible to create a highly reliable soil contamination map at the local scale, and to identify which factors have a significant impact when interpolating a small amount of soil heavy metal data.

• The Journal of Information Technology
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• v.8 no.1
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• pp.113-118
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• 2005

Investigation of surface discharge characteristics of surface leakage on polluted EPDM insulator have been performed. This work was performed utilizing High Frequency Current Trans former to monitor surface discharge. It was found that there were significant variation in the surface discharge waveform frequency spectrum, depending both on the surface discharge magnitude and more importantly on the duration of surface discharge activity.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.17.1-17.1
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• 2005

• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.627-634
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• 2001

Under contamination, Bahadur representations with a strong remainder term are derived for random central order statistics with a prescribed limiting rank, and asymptotic normalities for these statistics of truncated and contaminated data are proved, with a suitable limiting rank. From these results, an application to the fixed-width confidence interval problem is available.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.116-119
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• 2000

There has been a steady increase in geoenvironmental engineering projects where geotechnical engineering has been combined with environmental concerns. Many of these projects involve some investigation on contaminant and leachate flume in the ground and landfill. In this study, investigation and assesment on soil and groundwater around the waste landfill was carried out. Many techniques such as drilling and sampling method were applied. As a result of this study, the concentration of soil and groundwater were investigated and analysed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.9-12
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• 2001

MTBE is a gasoline additive which is widely used in the world. Its use on the air pollution reduction has been proved very effective, but has generated serious problems of groundwater contamination. Its use will be banned gradually by US EPA and other states governments in US. In Korea, it has been used since 1987 and its consumption reaches about 700, 000 tons/year. Any problems related to the groundwater contamination has not been reported in Korea, yet due to the lack of investigation. In this presentation, I raise the MTBE problems with examples of MTBE contaminations in the US.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.55.4-55
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• 2002

In the semiconductor fabrication, particle contamination is wide-spread and one of major causes to yield loss. Extensive testing has revealed that even careful handling of wafers during processing may cause photo-resist materials to flake off wafer edges. So, to remove the photo-resist at the outer 5mm of wafers, UV(Ultraviolet) rays are exposed. WEE (Wafer Edge Exposure) process station is the system that exposes the wafer edge as prespecified by controlling the positioning mechanism and maintaining the light intensity level In this work, WEE process station has been designed so as to significantly lower the amount of particle contamination which occurs even during the most r...

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.29-29
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• 2000

반도체 제조 공정을 비롯한 진공 산업에서는 진공 펌프에서 발생하는 backstream으로 인한 contamination이 주요 관심사가 되고 있다. 그러나 로타리 오일 펌프를 사용하는 경우에는 오일의 backstream으로 인한 contamination을 피할 수가 없어 현재는 오염 문제가 생산에 미치는 영향이 큰 반도체 공정에서는 건식 펌m을 적용/사용하고 있다. 본 발표서는 반도체는 제조 공정에 필수적으로 사용되고 있는 건식 펌프(dry pump)의 세계적 기술 동향을 살펴보고 건식펌프의 동작 원리 및 반도체 공정에서의 적용 사례등을 살펴보고자 한다.