• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.258-263
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• 2013

The primary goal of this study was to compute sample sizes required to achieve the each aim of a variety of foot-and-mouth disease (FMD) surveillance programs, using a statistically valid technique that takes the following factors into account: sensitivity (Se) and specificity (Sp) of diagnostic test system, desired minimum detectable prevalence, precision, population size, and desired power of the survey. In addition, sample sizes to detect FMD if the disease is present and also as proof of freedom were computed. The current FMD active surveillance programs consist of clinical, virological, and serological surveillance. For the 2012 serological surveillance, annual sample sizes (n = 265,065) are planned at four separate levels: statistical (n = 60,884) and targeted (n = 115,232) at breeding pig farms and slaughter house, in together with the detection of structural proteins (SP) antibodies against FMD (n = 88,949). Overall, the sample size was not designed taking the specific aims of each surveillance stream into account. The sample sizes for statistical surveillance, assuming stratified two-stage sampling technique, was based to detect at least one FMD-infected case in the general population. The resulting sample size can be used to obtain evidence of freedom from FMD infection, not for detecting animals that have antibodies against FMD virus non-structural proteins (NSP). Additionally, sample sizes for targeted surveillance were not aimed for the population at risk, and also without consideration of statistical point of view. To at least the author's knowledge, sampling plan for targeted, breeding pig farms and slaughter house is not necessary and need to be included in the part of statistical surveillance. Assuming design prevalence of 10% in an infinite population, a total of 29 animals are required to detect at least one positive with probability of 95%, using perfect diagnostic test system (Se = Sp = 100%). A total of 57,211 animals needed to be sampled to give 95% confidence of estimating SP prevalence of 80% at the individual animal-level with a precision of ${\pm}5%$, assuming 800 herds with an average 200 heads per farm, within-farm variance of 0.2, between-farm variance of 0.05, cost ratio of 100:1 of farm against animals. Furthermore, 779,736 animals were required to demonstrate FMD freedom, and the sample size can further be reduced depending on the parameters assumed.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.483-487
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• 2012

In 1895, the discovered X-ray is used for not only in this field of medicine wide but also field. The detection of radiation after, people realized the risk of the radiation exposured recommended the principle about the protection of radiation by the part of the effort for lowering the radiation exposure. In this recommendation, all unnecessary radiation exposure have to be prevented by All doses include the protection of radiation, general idea of applicable two kinds of that it has to low maintain. Presently, in the General X-ray room of the clinical, the lead (Pb) was used for the shielding, However, because it had the problem of the lead poisoning which is fatal in the human body, the alternatives was showed. and Among them, the material that it is the tungsten was presented. in this research, the absorbed spectrum according to the thickness in the continuous X-ray energy of the tungsten which is not harmful to the human body through the Monte Carlo simulation, tried to compare with the absorbed spectrum of the lead (Pb). The tungsten confirmed that simulation presumption than result lead in the whole domain that absorbed probability was higher and it is considered that tungsten shows the absorbed efficiency higher than the lead in particularly, 70 keV ~ 90 keV and the tungsten is more useful to the X-ray energy cover of the high energy diagnostic area.

• Journal of the Korean Geosynthetics Society
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• v.19 no.2
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• pp.23-33
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• 2020

This study determines the basic properties and acid rock drainage generation capacity of Pohang tertiary mudstone through laboratory experiments. According to X-ray fluorescence (XRF) analysis results, the mudstone of this area mostly comprised of SiO₂ with a proportion of approximately 60%, followed in order by Al₂O₃ and Fe₂O₃. As such, it is clear that there is an abundance of aluminosilicates with a high probability of generating acid rock drainage. The XRD analysis showed that the mudstone contains pyrite (FeS₂), it is highly likely to generate acid rock drainage, and inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis results showed that the mudstone samples contained a high amount of Fe²⁺ ions. As a result of anion analysis measured by ion chromatography (IC), all mudstone samples were measured to have high SO^2-₄ concentrations. According to elemental analysis, the total sulfur (S) content was high, which in turn indicates a high risk of acid rock drainage generation reflected by a maximum potential acidity (MPA) higher than 1%. All in all, although there were slight deviations between the tertiary mudstone samples, overall, the samples exhibited high acid rock drainage generation capacities.

• Environmental and Resource Economics Review
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• v.25 no.1
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• pp.1-25
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• 2016

This study investigated the variability of WTP estimates(i.e. mean or median) with ad hoc assumptions of specific parametric probability distributions(i.e. normal, logistic, lognormal, and exponential distribution) to estimate WTP function using dichotomous choice CV data on mortality risk reduction. From the perspective of policy decision, the variability of these WTP estimates are intolerable in comparison with those of Turnbull nonparametric estimation method which is free from ad hoc distribution assumptions. The Turnbull nonparametric estimation can avoid a kind of misspecification bias due to ad hoc assumption of specific parametric distributions. Furthermore, the WTP estimates by Turnbull nonparametric estimation are robust because the similar estimates are elicited from a dichotomous choice or double dichotomous choice CV data, and the statistically significant WTP estimates can be obtained even though it is not possible by parametric estimation methods. If there are considerable variability among those WTP estimates by parametric estimation methods in condition with no criteria of model adequacy, the mean WTPs from Turnbull nonparametric estimation can be the robust estimates without ad hoc assumptions, which can avoid controversial issues in the perspective of policy decisions.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.3
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• pp.1-10
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• 2008

The seismic performance of a structure designed without consideration of seismic loading can be effectively enhanced through seismic rehabilitation. The appropriate level of rehabilitation should be determined based on the decision criteria that minimize the anticipated earthquake-related losses. To estimate the anticipated losses, seismic risk analysis should be performed considering the probabilistic characteristics of the hazard and the structural damage. This study presents the decision procedure in which the probabilistic seismic demand model is utilized for the effective estimation and minimization of the total seismic losses through seismic rehabilitation. The probability density function and the cumulative distribution function of the structural damage for a specified time period are established in a closed form, and are combined with the loss functions to derive the expected seismic loss. The procedure presented in this study could be effectively used for making decisions on the seismic rehabilitation of structural systems.

• The Korean Journal of Community Living Science
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• v.16 no.2
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• pp.39-50
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• 2005

For the life quality improvement of rural elderly family placed in risk of frail, this study was investigated. Health habit, food habit, and dietary management were analyzed between elderly and middle aged family The subjects 1870 collected in 9 provinces 88 cities or guns by sampling with probability proportional to size(PPS). Questionnaire method was used. Survey was conducted by trained interviewers. Statistical analyses were performed using SAS(version 8.1). Chi-square tests and General Linear Models were used. The elderly families' characters were odd pair$(42.0\%)$, with patients$(17.6\%)$ and health examination per 1 or 2 years$(44.0\%)$. The elderly families' health habit: high of no-drink$(55.2\%)$ and low of smoke$(31.3\%)$ situation was better than those of middle aged families'. The states of diets of elderly family: having breakfast$(94.1\%)$ but 1-2 kinds$(17.7\%)$ or 3-4 kinds$(59.4\%)$ of side dishes allowed to guess lower status of food intake balance. Nutritional supplements$(27.5\%)$with tablets of vitamins$(63.5\%)$ were the most frequent states in elderly family. The aspects of dietary habit of elderly family: no instant foods$(72.6\%)$, no snack$(3.08\%)$ and no dine-out$(67.7\%)$ were significantly different with those of middle aged family. Dietary habit score(8.28/12 points) of elderly family was not significantly different with 8.22/12 points of middle aged family. Food purchase place of elderly family was mainly at traditional market$(43.6\%)$, but it was significantly different with super-market$(47.6\%)$ of middle aged family. In elderly family, traditional dish preparation was seldom$(49.8\%)$ except winter kimchi$(91.5\%)$, but significantly higher rate of in middle aged families' traditional dish preparation and winter kimchi$(94.5\%)$. From these results, more of snack, traditional dishes and dine-out were needed to improve quality of life for rural elderly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.29-41
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• 2017

Design rainfalls are one of the most important hydrologic data for river management, hydraulic structure design and risk analysis. The design rainfalls are first estimated by a point frequency analysis and the IDF (intensity-duration-frequency) curve is then constructed by a nonlinear regression to either interpolate or extrapolate the design rainfalls for other durations which are not used in the frequency analysis. It has been widely recognised that the more reliable approaches are required to better account for uncertainties associated with the model parameters under circumstances where limited hydrologic data are available for the watershed of interest. For these reasons, this study developed a hierarchical Bayesian based GLM (generalized linear model) for a regional frequency analysis in conjunction with a scaling function of the parameters in probability distribution. The proposed model provided a reliable estimation of a set of parameters for each individual station, as well as offered a regional estimate of the parameters, which allow us to have a regional IDF curve. Overall, we expected the proposed model can be used for different aspects of water resources planning at various stages and in addition for the ungaged basin.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.557-565
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• 2016

The risk of collapse in hydraulic structures has become more elevated, due to the increased probability and scale of flooding caused by global warming and the resulting abnormal climatic conditions. When a levee, a typical hydraulic structure, breaks, an enormous breach flow pours into the floodplain and much flood damage then occurs. It is important to accurately calculate the breach discharge in order to predict this damage. In this study, the variation of the breach discharge with the asymmetry in the cross-section of the levee breach was analyzed. Through hydraulic experiments, the cross-section of the breach was analyzed during the collapse using the BASD (Bilateral ASymmetry Degree), which was developed to measure the degree of asymmetry. The relationship of the breach discharge was identified using the BASD. Additionally, the variation of the breach flow measured by the BASD was investigated through a 3-D numerical analysis under the same flow conditions as those in the experiment. It was found that the assumption of a rectangular breach cross-section, which is generally used for the estimation of the inundation area, can cause the breach discharge to be overestimated. According to the BASD, the breach flow is decreased by the interference effect in the breach section of the levee. If the breach flow is calculated while considering the BASD in the numerical analysis of the flooding, it is expected that the predicted inundation area can be estimated accurately.

• Radiation Oncology Journal
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• v.4 no.2
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• pp.99-105
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• 1986

Optimal balance between control probability and risk of complication is emphasized even in present time, Although certain incidence of intestinal injury is accepted as an inevitable consequence after abdominopelvic irradiation, these complications still remain as problems. 60 mice were irradiated with 250 kVp orthovoltage x-ray machine and $200rad{\times}5/wk$ regimen. Histpathologic findings of colorectum and the relationship with occult blood test were analyzed and possible tolerable dose which would be safe from permanent complication was also estimated. Followings are the results: Mild mucosal and submucosal edema were observed in 1,000 rad irradiated group. Congestion of small vessels was prominent in 2,000 rad irradiated group and infiltration of inflammatory cells was observed in 3,000 rad irradiated group. Denuded mucosa was observed in 3,000 rad irradiated group. Occult blood test is not a proper indicator for rectal denuding or rectal ulcer, but our results suggest the possibility of using this as a relative scale of intestinal damage. Mitotic figures of crypt cells were observed even in 5,000 rad irradiated group, these suggest that the repair capacity of crypt cells are still functioning.

• Journal of Wetlands Research
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• v.15 no.1
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• pp.105-114
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• 2013

Recently, Due to Climate change, extreme rainfall occurs frequently. In many preceding studies, Because of extreme hydrological events changes, it is expected that peak flood Magnitude and frequency of drainage infrastructures changes. However, at present, probability rainfall in the drainage facilities design is assumed to Stationary which are not effected from climate change and long-term fluctuation. In the future, flood control safety standard should be reconsidered about the valid viewpoint. In this paper, in order to assess impact of climate change on drainage system, Future climate change information has been extracted from RCP 8.5 Climate Change Scenario for IPCC AR5, then estimated the design rainfall for various durations at return periods. Finally, the design flood estimated through the HEC-HMS Model which is being widely used in the practices, estimated the effect of climate change on the Design Flood of Mihochen basin. The results suggested that the Design Flood increase by climate change. Due to this, the Flood risk of Mihochen basin can be identified to increase comparing the present status.