• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.632-636
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• 2005

Accelerated soil erosion is a worldwide problem because of its economic and environmental impacts. To effectively estimate soil erosion and to establish soil erosion management plans, many computer models have been developed and used. The Revised Universal Soil Loss Equation (RUSLE) has been used in many countries, and input parameter data for RUSLE have been well established over the years. However, the RUSLE cannot be used to estimate the sediment yield for a watershed. Thus, the GIS-based Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed to estimate soil loss and sediment yield for any location within a watershed using the RUSLE and a spatially distributed sediment delivery ratio. SATEEC was enhanced in this study by developing new modules to:1) simulate the effects of sediment retention basins on the receiving water bodies, 2) prepare input parameters for the Web-based sediment decision support system using a GIS interface. This easy-to-operate SATEEC system can be used to identify areas vulnerable to soil loss and to develop efficient soil erosion management plans.

• YAKHAK HOEJI
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• v.51 no.1
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• pp.1-6
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• 2007

The aim of this study was to examine whether administration of glutamine are able to prevent the methotrexate induced gut barrier damage, bacterial translocation, and weight changes. The animals with glutamine were fed with L-glutamine (1.2 and 2.4 mg/kg/day) for 7 days before methotrexate administration (20 mg/kg orally). 48 hour after methotrexate administration, intestinal permeability were measured for an assessment of the gut barrier dysfunction. Also, enteric aerobic bacterial counts, number of gram-negatives in mesenteric lymph node (MLN), liver spleen, kidney and heart were measured for an assessment of the enteric bacterial number and bacterial translocation. Amounts of food intake, body weight changes and organ weight changes of liver spleen, kidney and heart were measured. Methotrexate administration caused body and liver weight loss regardless amounts of food intakes. Methotrexate induced increasing intestinal permeability, enteric bacterial undergrowth and bacterial translocation to MLN, liver and spleen, but not kidney and heart. The supplements with glutamine reduced the intestinal permeability bacterial translocation, and not influences enteric bacterial number, and body and liver weight changes. This study suggested that glutamine might effectively reduce methotrexate induced intestinal damage and bacterial translocation, but not influence body and organ weight loss.

• Earthquakes and Structures
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• v.13 no.4
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• pp.387-396
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• 2017

The first determination and assessment of the damages to structures after the earthquake is important for preventing increase in loss of life and property that may occur in later times. When rapid damage assessment is performed after an earthquake, damage assessment forms are generally used. The forms that are filled in the field are assessed in the office environment later. In this study, while the process of earthquake damage assessment was being carried out, the ready-made form was moved to web base and the data to be obtained in the field was transferred to the database by means of tablets and smart phones. Keeping earthquake damages in a database will contribute to the studies to be conducted on earthquake and the earthquake regulations to be prepared. Furthermore, emergency damage assessment will be performed faster and more reliably after the earthquake through this study. As the data transferred to the web base is accessible to different people, savings will be provided for both time and personnel. Furthermore, the assessment will have a healthier and scientific basis. In this study, exemplification was conducted for six different reinforced concrete buildings that were damaged during Van earthquake in October 23. With this study, damage assessment procedures can be completed as soon as possible.

• Journal of Korean Academy of Nursing
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• v.41 no.6
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• pp.758-767
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• 2011

Purpose: This study was done to examine the threshold value of estimated height loss at which the risk of osteoporosis increases and to verify its discriminative ability in the detection of osteoporosis. Methods: It was conducted based on epidemiological descriptive methods on 732 Korean women at a public healthcare center in Seoul between July and November 2010. ANOVA, Pearson correlation, logistic regression analysis and receiver operating characteristics (ROC) curve were used for data analysis. Results: There was an age-related correlation between bone mineral density (lumbar spine: F=37.88, p<.001; femur: F=54.27, p<.001) and estimated height loss (F=27.68, p<.001). Estimated height loss increased significantly with decreasing bone mineral density (lumbar spine: r=-.23, p<.001; femur: r=-.34, p<.001). The odds ratio for the point at which the estimated height loss affects the occurrence of osteoporosis was found to increase at a cut-off value of 2 cm and the area under ROC curve was .71 and .82 in lumbar spine and femur, respectively. Conclusion: The optimal cut-off value of the estimated height loss for detection of osteoporosis was 2 cm. Height loss is therefore a useful indicator for the self-assessment and prognosis of osteoporosis.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.61-68
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• 2006

The factors influencing long-term prognosis of teeth must be carefully considered. Among these, attachment level is strongly associated with tooth loss. The purpose of the present study was to estimate pattern of attachment loss based on attachment area in extracted teeth. 197 satisfied the criteria for assessment after staining. The protocol described by Waerhaug(l975) was performed. An indir ect method, based on digital image abstracted from digital camera and digital imaging software program, was used to calculate the root surface area and the attachment loss area. The data were analysed using SPSS. Except maxillary central incisior and mandibular canine, no statistical significant differences between each root surfaces were observed in anterior teeth. In posterior teeth, statistical significant differences in palatal surface of maxillary molar and mandibular molar compared with others were observed. Statistical significant difference in buccal surface compared with others was lowly observed in single and multi rooted. This study did not reveal progressive loss pattern of attachment area in each root surface but clarified root surface that has relative high loss rate of attachment area at extraction. Thus understanding this pattern of attachment loss is helpful for dentist to treat the periodontitis.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.187-194
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• 2016

A single fire event within a fire area can cause multiple initiating events considered in internal events probabilistic safety assessment (PSA). For an example, a fire event in turbine building fire area can cause a loss of the main feed-water and loss of off-site power initiating events. This fire initiating event could result in special plant responses beyond the scope of the internal events PSA model. One approach to address a fire initiating event is to develop a specific fire event tree. However, the development of a specific fire event tree is difficult since the number of fire event trees may be several hundreds or more. Thus, internal fire events PSA model has been generally constructed by modifications of the pre-developed internal events PSA model. New accident sequence logics not covered in the internal events PSA model are separately developed to incorporate them into the fire PSA model. Recently, many fire PSA models have fire induced initiating event fault trees not shown in an internal event PSA model. Up to now, there has been no analytical comparative study on the constructions of fire events PSA model using internal events PSA model with and without fault trees of initiating events. In this study, the changing process of internal events PSA model to fire events PSA model is analytically presented and discussed.

• Journal of Environmental Impact Assessment
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• v.27 no.1
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• pp.33-55
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• 2018

It has been noted that the main cause of biodiversity loss is influx of alien species. Specifically, habitats destruction, economic loss, and human injury are increasing due to invasive alien species. There were 2,167 alien species in Korea. 21 alien species of extraterrestrials including Lycorma delicatula, Solenopsis invicta, Myocastor coypus, and Spartina alterniflora at high risk through ecological risk assessment, are designated as invasive alien species. Alert species, which may have negative impact on ecosystems when they are introduced into the country, are assigned to 127 species through the ecosystem risk evaluation. To list such alien species to prevent invasion of alien species in advance, and to minimize damage caused by imported alien species, a national level management system called the Conservation and Use of Biological deversity Act was established, but there is a lack of a systematic management system in accordance with degree of risk. There is also a risk assessment chart should be developed thatreflects ecological characteristics of each taxon and evaluation criteria in predicting the risk.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.860-866
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• 2022

An accurate prediction of the pressure drop along the flow paths is crucial in the design of advanced passive systems cooled by heavy liquid metal coolants. To date, a generic pressure drop correlation over spacer grids by Rehme has been applied extensively, which was obtained from substantial experimental data with multiple types of components. However, a few experimental studies have reported that the correlation may give large discrepancies. To provide a more reliable correlation for ring-type spacer grids, the current numerical study aims at figuring out the most critical factor among four hypothetical parameters, namely the flow area blockage ratio, number of fuel rods, type of fluid, and thickness of the spacer grid in the flow direction. Through a set of computational fluid dynamics simulations, we observed that the flow area blockage ratio dominantly influences the pressure loss characteristics, and thus its dependence should be more emphasized, whereas the other parameters have little impact. Hence, we suggest a new correlation for the drag coefficient as C_B = C_ν,m/ε^2.7, where C_ν,m is formulated by a nonlinear fit of simulation data such that C_ν,m = -11.33 ln(0.02 ln(Re_b)).

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.158-164
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• 2008

Abstract Infiltration of rainfall that may lead to reduce resistance force due to reduction of matric suction and to increase driving force due to increase of self weight makes the slope fail. There are many specifications to make slope stable based on factor of safety. Although result of slope stability analysis satisfy the specifications, slope failures triggered by rainfall are frequently occurred in reality because slope stability analysis cannot consider uncertainty of each soil properties. This is why conventional analysis has limitation and development of alternative method is needed. So it is suggested to adopt the reliability analysis rather than design based on factor of safety into designing safer structure. Through the evaluation of handicaps for the factor of safety based design, calculation of soil properties by site investigation, and reliability analysis considering distribution of each soil properties, distribution of failure probability in railway slope is obtained. Then, Risk assessment of slopes in Korean railway is executed from the results. Damage loss and incoming loss are considered as the loss. Using these results, it is possible to make proper countermeasure or efficient maintenance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.9
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• pp.1183-1188
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• 2013

The reliability of hydraulic equipment used in power plants is especially important because failures that occur in the power plant can have a great ripple effect on human lives and financial losses. In this study, specimens using the materials used in the spool and sleeve of hydraulic valves of power plants have been produced, heat-treated, and tested under the precipitation conditions of phosphate ester hydraulic fluid with a variety of conditions. 23 full factorial designs have been applied to evaluate the significance of factors that affect the wear loss of the specimen, specifically, the load, velocity, and temperature. The significance evaluation was performed on the main effects and two-way interactions for wear loss based on the experiment results, and the mathematical equations between the wear loss and the three factors were derived from the analysis results.