• Analytical Science and Technology
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• v.19 no.5
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• pp.389-393
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• 2006

The detector consisted of ZnS(Ag) scintillator and photomultiplier tube (PMT) is widely used as contamination monitor in the nuclear facilities. Such detectors are mainly manufactured by adhering the ZnS(Ag) powder onto the transparent plastic. In this study the preparation condition for ZnS(Ag) scintillator sheet using a simple method was established. The scintillator sheet was composed with a support polymer sheet and ZnS(Ag) scintillator layer. The base sheet was prepared by casting the polymer solution after solving the polymer with solvent and the scintillator layer was manufactured by printing the mixture solution with ZnS(Ag) and paste. It was found that the polysulfone(PSf) as a polymer for the base sheet and a cyano resin as a paste for adhering the ZnS(Ag) scintillator was suitable. Also, the prepared thin scintillator sheet had a sufficient mechanical strength, a optical transparency and an alpha-ray detection performance.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1216-1221
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• 2012

This study is aimed to investigate microbiological contamination of Angelica gigas Nakai. A total of 111 samples including root, soil, and irrigation water were collected from farms and market to detect aerobic bacteria, Bacillus cereus, coliform, Escherichia coli, Listeria monocytogenes,. Salmonella spp., and Staphylococcus aureus. The contaminations of aerobic bacteria, coliform, and Bacillus cereus in the root during cultivation were found 6.71 log CFU $g^{-1}$, 4.13 log CFU $g^{-1}$, and 3.54 log CFU $g^{-1}$, respectively. The contamination of coliform and B. cereus were detected in all steps from harvesting to processing, with the highest count recorded from the cutting step. In marketing, the contaminations of aerobic bacterial, coliform, and B. cereus were 5.5~6.0 log CFU $g^{-1}$, 2.4~2.6 log CFU $g^{-1}$, and 3.5~4.0 log CFU $g^{-1}$, respectively. Listeria monocytogenes, Salmonella spp, and Staphylococcus aureus were not detected in any of samples. This result indicated that hygienic soil management and post harvest management should be performed to reduce the contamination of hazard microorganisms and to produce safe agro-products.

• Korean journal of food and cookery science
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• v.23 no.3 s.99
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• pp.302-313
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• 2007

The purpose of this study was to investigate the gap in perceived importance-performance between dietitians and parents regarding school foodservice sanitation practices, to establish a plan for improving the school foodservice monitoring that is conducted by parents. A survey was given using questionnaires and was distributed to 31 school foodservice dietitians and to parents who attended sanitation education in October 2006. All statistical analyses were conducted using the SAS package program(version 8.2 for Windows) for descriptive analysis, t-test, and importance-performance analysis(IPA). The results of the IPA showed the following areas as improvement priorities: (1) contracting with a reliable suppliers, (2) securing proper refrigerator and freezer capacity and checking temperatures, (3) adequate design and construction of foodservice facilities and equipment, and (4) ensuring trays and utensils are clean, dry, and stored in a way that prevents contamination. The results of the IPA illustrated that school foodservice dietitians performed well in 8 out of the 21 sanitation management items. The perceived importance by parents was higher than by dietitians for accurate record keeping and documentation of HACCP worksheets(p<0.01), appropriate cleaning plans and practices(p<0.05), garbage management of inner kitchens (p<0.05), and garbage management of external kitchens(p<0.05). On the other hands, the perceived importance by dietitians was higher than that of parents for contracting with a reliable suppliers(p<0.05) and adequate design and construction of foodservice facilities and equipment(p<0.01). According to the performance analysis there were significant differences between dietitians and parents in six out of the twenty-one items. For these six items, the evaluated degree of performance by parents was higher than that of dietitians. In conclusion, proper education programs should be planned and regularly performed for the student's patents who take part in school foodservice monitoring in order to improve on their monitoring.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.178-183
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• 2008

Recently, sick house syndrome caused by pollutants and contamination of buildings crops out in residential environment of buildings. According to price increase of global oil, comfort of occupants in indoor air quality is required with reduction of energy consumption and environmental load. So, building performance certification criteria come into effect for improvement of building energy efficiency and performance in environment at home and abroad. GBCC(Green Building Certification Criteria) of domestic country as a Criteria is managed Korea Green Building Council(KGBC) for green building. Thus, purpose of this study is to design a direction of Green Building Certification Criteria for improvement through analysis of GBCC application elements and selected building.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.263-270
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• 2010

In this study, an air cleaner is considered to improve comfort, safety, and health of automobile passengers. The performance and installation conditions of the air cleaner have been studied to investigate their effects on the air quality in the cabin room using numerical analysis. A five-passenger sedan and a seven-passenger minivan that have comparatively large indoor volume have been considered. The distributions of the local mean age and the volume averaged age of indoor air are calculated according to the variation of the placement and the air flow of the air cleaner. In addition, a decrease of contamination concentration, especially VOCs(volatile organic compounds), by the air cleaner is numerically analyzed with time-accurate unsteady calculation to quantify the effect of the air cleaner on the indoor air quality. As a result, the effective installation and operation conditions of the air cleaner for the automobile cabin room could be suggested.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.278-281
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• 2007

The purpose of this study is to develop snow and sea ice detection algorithm in Communication, Ocean and Meteorological Satellite (COMS) meteorological data processing system. Since COMS has only five channels, it is not affordable to use microwave or shortwave infrared data which are effective and generally used for snow detection. In order to estimate snow and sea ice coverage, combinations between available channel data(mostly visible and 3.7 ${\mu}m$) are applied to the algorithm based on threshold method. As a result, the COMS snow and sea ice detection algorithm shows reliable performance compared to MODIS products with channel limitation. Specifically, there is partial underestimation over the complicated vegetation area and overestimation over the area of high level clouds such as cirrus. Some corrections are performed by using water vapor and infrared channels to remove cloud contamination and by applying NDVI to detect more snow pixels for the underestimated area.

• Mycobiology
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• v.42 no.4
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• pp.339-345
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• 2014

During 2011~2013, a total of 729 samples for 19 types of medicinal plant were collected from Seoulyekryungsi in Seoul, Korea, and investigated for the presence of aflatoxins. The samples were analyzed using immunoaffinity column cleanup and high-performance liquid chromatography coupled to a fluorescence detector after post-column derivatization. Aflatoxins were found in 124 out of the 729 analyzed samples: 65 containing aflatoxin B1 (AFB1), 24 with aflatoxin B2 (AFB2), 15 with aflatoxin G1 (AFG1), and 20 samples with aflatoxin G2 (AFG2). The ranges for positive samples were $0.1{\sim}404.7{\mu}g/kg$ for AFB1, $0.1{\sim}10.0{\mu}g/kg$ for AFB2, $0.1{\sim}635.3{\mu}g/kg$ for AFG1, $0.1{\sim}182.5{\mu}g/kg$ for AFG2, and $0.1{\sim}1,043.9{\mu}g/kg$ for total aflatoxins. Most of the medicinal plant samples (721, 98.9%) were below legal limits, but 8 samples exceeded the legal limits of 10 and $15{\mu}g/kg$ established by the Korean standard for AFB1 and total aflatoxins (the sum of AFB1, AFB2, AFG1 and AFG2), respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.1
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• pp.63-70
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• 2009

The air sterilization systems are investigated experimentally in this paper. The goal is to reduce bacteria, mold and viruses in office air by using a UV sterilizer installed inside a partition panel and wall-mounted unit. These systems allow occupants to turn the system on/off and to control the incoming air speed and direction. The partition air sterilization system conditions and sterilizes the air, and then delivers the clean air into the personal task area through the partition panels, which are connected to the pressurized under-floor plenum. Room air exits through the return grills mounted on the ceiling. The wall-mounted air sterilization system sterilizes the air, and then delivers the clean air to the personal task area from the wall. In this study a full-size experimental environment is established to investigate the immunization performance of these air sterilization systems. A typical office space scale is used in this study in order to find an optimal system to achieve a sterilized healthy micro-environment. Multiple system parameters, including volume flow rate and velocity of supplied air, were regulated during the experiments. The more air contact these air sterilization systems had, the better disinfection performance. Over 90% of eradication ratios were obtained by these two air sterilization systems. The results indicate that these systems can efficiently disinfect office air contamination.

• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.134-141
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• 2014

A testing inspection is one of the important in the industry, owing to determine the reliability and directivity of testing inspection results. Therefore, the quality assurance and quality control (QA/QC) work which performed by personnel not directly in the inventory compilation development, in testing inspection must be thoroughly considered. Some agencies for environmental test inspection, they sometimes misunderstood that the QA/QC was ended with proficiency testing performance and on-site assessment by a director. Thus, results were often calculated without QA/QC work by self manual when conducting test. The objective of this study was to improve reliability of testing and inspection agency through the QA/QC case study which basically performed to raising reliability of testing and inspection agency. In this study, it increased reliability of result by verifying calibration curve (IC, ICV, CCV), blank, accuracy (LCS, MS) and precision as QA/QC performance, while performing investigation of soil contamination in mining areas. This study suggests that reliability establishing method of test result and management method of analysis process, through the QA/QC instance of testing agency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.237-253
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• 2019

For massive multiple-input multiple-output (MIMO) circumstances with time division duplex (TDD) protocol, pilot contamination becomes one of main system performance bottlenecks. This paper proposes an uplink pilot sequence assignment to alleviate this problem for spatially correlated massive MIMO circumstances. Firstly, a single-cell TDD massive MIMO model with multiple terminals in the cell is established. Then a spatial correlation between two channel response vectors is established by the large-scale fading variables and the angle of arrival (AOA) span with an infinite number of base station (BS) antennas. With this spatially correlated channel model, the expression for the achievable system capacity is derived. To optimize the achievable system capacity, a problem regarding uplink pilot assignment is proposed. In view of the exponential complexity of the exhaustive search approach, a pilot assignment algorithm corresponding to the distinct channel AOA intervals is proposed to approach the optimization solution. In addition, simulation results prove that the main pilot assignment algorithm in this paper can obtain a noticeable performance gain with limited BS antennas.