• Journal of Society of Preventive Korean Medicine
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• v.19 no.3
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• pp.103-113
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• 2015

Objective : Five most generally adopting basic oriental prescriptions (yookmijihwangtang, ojeoksan, sipjeondaebotang, samultang, bojoongikgitang) samples were collected from 10 oriental hospitals nationwide and the transferring ratio to aqueous phase (TRAP) were calculated. Method : The samples are grounded evenly and the decocted at $120^{\circ}C$ for 12 min on hot plate and then filtered. The concentrations of As, Cd, Co, Cr and Pb in before and after decoction were measure by ICP/MS and the TRAPs were calculated. Results : The concentrations of As, Cr and Pb in the ground samples before decoction were all below criteria level, and TRAP values were also very low (<10%). For Cd, although some ground samples before decoction showed relatively high concentration level compare to the criteria level, because of their low TRAP (~3%), the actual concentrations in the decoction were quite low compare the criteria level. The Co's concentrations in the ground samples before decoction were all relatively low level. However, the TRAP of Co was astonishingly high value of around 40% average. Conclusion : The toxic heavy metal concentrations in the decoction were very low compare to the criteria level. The TRAPs are less than <10% except Co. The toxic heavy metals in the prescriptions are mainly remained in the residue and the only very small fraction may transferred to the decoctions. Therefore the toxicity of the oriental herbal medicine about the toxic heavy metal may be overstressed. The Co's TRAP turned out to be quite high value (40% average). Since the criteria level wes not established yet, the safety of decoctions according to Co was not fully confirmed.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.17-26
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• 2014

Background: Despite children's unique characteristics that distinguish them from adults, relatively few attempts have been made to measure exposure factors for characterization of children's exposure to hazardous chemicals in child-specific products (CSP). This study was conducted to establish the child-specific exposure factors for exposure and risk assessment of hazardous substances in CSP. Methods: We investigated the exposure factors (e.g., time use of child-products, time and frequency of object-to-body contact, time and frequency of object-to-mouth contact) influencing children's exposure to CSP (e.g., toys, playmats, oil pastels, etc.) in 650 children through a parent-completed questionnaire using a web-based survey. Participants were recruited in five age groups, <1, 1-2, 2-3, 3-6, and 6-12 years of age. Results: The child-specific exposure factors were presented as the mean, median, $95^{th}$ percentile, minimum, and maximum values. Time activity for play mats was the longest among CSP and infants spent more time on them than did elder age groups (189.3-224.7 min/day for <1-2 years vs. 91.2 min/day for 6-12 years). It is apparent that time and frequency of toy block- and plastic toy-to-mouth contact significantly decreased as a function of age. When the variation of CSP use patterns was compared by gender, the only variable that was statistically different between genders was time activity in child-products exposure space. Conclusion: We believe the five child-specific exposure factors suggested in the present study will be valuable for reducing uncertainty in the estimation of chemical exposure during risk assessment of CSP and furthermore, in the appropriate regulations to protect children's health.

• Journal of Biosystems Engineering
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• v.32 no.3
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• pp.153-159
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• 2007

This study was conducted to measure and analyze the noise from a combine head. The combine head, comprised of a cutting knife assembly, pick-up chains, horizontally conveying chains and vertically conveying chains, had an overall sound level of 101 dBA. The sound levels of each component were, respectively, 98.3 dBA for the cutting knife assembly, 88.9 dBA for the pick-up chains, 79.8 dBA for the horizontally conveying chains and 86.3 dBA for the vertically conveying chains, being equivalent to 54.4%, 18.4%, 6.5% and 13.7% of the overall head noise. The main cause of the head noise was considered the impacts that the joint of the cutting knife assembly made with frame when it oscillated. The impact sound was also generated when the chain lug collided with the chain case. To reduce these impact sound, anti-vibration rubbers were installed on the knife assembly joint and the chain cases. It reduced the head noise by 4 dBA but the overall noise level of the combine head was still high. In order to protect the combine operators more effectively from the noise, a safety cab needs to be installed on the combine.

• Fire Science and Engineering
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• v.16 no.1
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• pp.45-50
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• 2002

This study set its bases needed for building fire risk analysis by examining general concept and definitions of fire risk analysis, and its access methods. Upon this basis, by using a computer program FREM, we brought the type of hazards out of the fire risk assessment applied to the typical 100 high-rise buildings in and out of this country. In this process, we also sorted out the programs arising from the application of a foreign born tool to domestic conditions. the credibility of fire separations and automatic fire protection system in a building would be the two most important things in an attempt to evaluate fire risk in high-rise buildings. In addition, it is vital for the purpose of securing fire safety in high-rise buildings that the systems should be properly installed and carefully maintained. When we try hard to study the evaluation standards to the above systems and, someday in the future, to employ them in evaluating fire risks in high-rise buildings, we can measure the risks much more precisely with less expenses than that we needed today.

• Fire Science and Engineering
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• v.27 no.6
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• pp.38-43
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• 2013

As a preliminary study to evaluate the reliability of the calculation method of fire load for residential furniture combustibles, the present study estimates the fire load considering the volume data obtained by the 3D geometrical information of combustibles and material properties based on the literature survey and sample burning test. A kitchen sink cabinet, couch and workstation were investigated for estimating its fire load and real fire test have been performed to measure total energy released from the combustibles. Based on total energy measured from real fire test, the relative error of the estimated fire load due to literature survey and measured material properties showed 6~120% and less than 20%, respectively. It shows that the estimation error of fire load are greatly affected by its material properties as well as geometrical information of combustibles and the present study will be able to contribute to accurate estimation of fire load.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.1
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• pp.11-19
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• 2004

Such social structures as bridges,, buildings, dams and towers have been transformed by their own load or fundamental ground. They have been behaved by other external causes. These regular or irregular behaviors threaten to do their users safety. Therefore, to monitor the load of the structures or reaction shown by them could help to verify their behaviors. RTK GPS allows the use of a static base station and remote rover unit to allow f3r data collection within several seconds and in real time. It is useful for monitoring the behaviors of massive structures like bridges. In this Study, Among GPS methods, we used RTK GPS to analyze the precision of monitoring and then on the basis of it, we developed a monitoring system using RTK GPS when measured the behavior of main tower of a suspension bridge by using RTK GPS. Comparing a deviation between observation values, X axis was Imm, Y axis was 1mm and Z axis 2.2mm. It turned out that it was possible to monitor and measure structures by RTK GPS.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.1
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• pp.21-30
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• 2007

To establish the Fourier-transform infra-red spectrophotometry (FTIR) direct-on-filter(DOF) technique as a useful analytical method for quartz in respirable dust samples, influence of the interference should be corrected. This study was designed to compare three methods of correction for cristobalite when quantifying the content of quartz, including the least square, the optimum choice and the spectral subtraction methods. Respirable dust, created in a dust chamber containing the standard material of quartz, cristobalite was collected using a cyclone equipped with a 25 mm, $0.8{\mu}m$ pore size DM filter as a collection medium. The quartz weights overestimated about 100% when mixed of cristobalite by measure using 799 cm-1 absorption peak of quartz. The quartz weights appeared over estimated by optimum choice, spectral subtraction and least square method in mixtures of 33% cristobalite were 90.3%, 60.1% and about 4.3%, respectively. The least square method have been adopted to correction methods of cristobalite and satisfactory results have been obtained. The results of this study suggest that, when correcting for effect of cristobalite on quantitative analysis of quartz in respirable dust by FTIR direct-on-filter method, the least square method produce the most unbiased results compared with those of other correction methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3451-3457
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• 2010

Cyber security assessment is the process of determining how effectively an entity being assessed meets specific cyber security objectives. Cyber security assessment helps to measure the degree of confidence one has and to identify that the managerial, technical and operational measures work as intended to protect the I&C systems and the information it processes. Recently, needs for cyber security on digitalized nuclear I&C systems are increased. However the overall cyber security program, including cyber security assessment, is not established on those systems. This paper presents the methodology of cyber security assessment which is appropriate for nuclear I&C systems. This methodology provides the qualitative assessments that may formulate recommendations to bridge the security risk gap through the incorporated criteria. This methodology may be useful to the nuclear organizations for assessing the weakness and strength of cyber security on nuclear I&C systems. It may be useful as an index to the developers, auditors, and regulators for reviewing the managerial, operational and technical cyber security controls, also.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.50-62
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• 2003

Exposure to metalworking fluids (MWFs) has significantly been associated with cancer developed in multi-organs, respiratory diseases and skin diseases. Several carcinogens to humans or animals are contained in MWFs. They have been reported to be mineral oils, polynuclear aromatic hydrocarbons (PAHs), formaldehyde and N-nitrosodiethanolamine (NDELA). The great hazards of MWF have forced the advanced country including United States to regulate carcinogens contained in MWF. In 2001, American Conference of Governmental Industrial Hygienists (ACGIHs) regarded MWF mist as suspected carcinogen to human (A2) and added it to “Notice of Intended Change (NIC)” list of 2001. In spite of the fact that much MWF has widely been used in many industries using machines, Korea has no legal actions for management of MWF. What is worse, even toxicity such as Carcinogenicity has not been reported. KS (Korean Standards) lists 7 advices of MWF but it does net state the hazards to health. It is very hard to control or minimize worker's exposure to MWF containing many carcinogens. Prier to the introduction of MWF to workplace, it is the most effective measure to regulate carcinogens below a certain level. Regulation on the content of PAH seems to be necessary because less amount of PAH in mineral oils improves the quality of MWF. Also, addition of nitrosating groups to MWF should be prohibited to minimize worker's exposure to NDELA. Employers and manufacturers should indicate the Carcinogenicity of all carcinogens in MWFs in Material Safety Data Sheets (MSDS) in order fer workers to recognize Carcinogenicity. Legal actions have to be taken to protect workers from health hazards due to exposure to MWF by further investigation on MWF.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.2 s.115
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• pp.44-56
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• 2006

The purpose of this study was to analyze user satisfaction for park facilities in Bukhansan National Park and to introduce a new framework of standards for facilities improvement. An initial theoretical model considered possible variables through a case study of user satisfaction for park facilities and eventually 19 variables were chosen. An analysis was conducted of the user's satisfaction based on their expectations before use and the results after use. This expectancy-result disconfirmation was measured for the 19 variables. Statistical methods were applied to determine the reliability of the analysis, the t-test was used to measure disconfirmation between expectations and results, and relationships between the variables were analyzed. The results of the reliability analysis (Cronbach's alpha) were higher than 0.8. Therefore, almost all variables were appropriate for analysis. Statistically significant differences were found between expectations and results for following variables: availability of information facilities and accessibility, convenience of facilities, number of information facilities, appropriateness of information facilities, information offered, safety and convenience. Based on the analysis of the interrelation between variables, it was found that the visitors were more satisfied after their visit than they expected to be. The results of the study suggest which variables make the greatest contributions to facilities maintenance or improvement and which can be adapted to maximize user satisfaction.