• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.1
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• pp.53-68
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• 1992

This study was carried out to estimate the recreation carrying capacity of lawn areas in parks. Recreation carrying capacity in this study is composed of two parts, ecological carrying capacity and psychological carrying capacity. As the first part, this paper deals with the treading times criteria based on the tolerence of the turf to treading pressure. The plant material used for this study was Zoysia japonica, and the treading experiment was done in the experimental fields in Kyungju and Suwon, Korea. The major results of the first part of the study are summarized as follow: 1. As shown in annual change of the growth of the turf, The growth of turt grass was represented by the number of leaf. 2. The tolerance to treading was not significantly different by the time of treading treatment. And the tolerance varies depending on growth rate of grasses, which showed significant relationship with precipitations. 3. From the result of different numbers of simulated treading treatment, the damage of the turf was increased by the increase of the frequency of treading. And the damage was very serious within short period(about 20 days) in high frequency(over 20 times/day) of treading treatment. But low frequency(1∼3times/day) of treading shows good effects on the growth of the turf. 4. The criteria of treading number per day for each carrying capacity level are estimated as 7 times/day for optimum carrying capacity, 13 times/day for standard carrying capacity, and 20 times/day for critical carrying capacity.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.68-75
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• 2018

The safety management cost system under the Construction Technology Promotion Act has contributed greatly to the prevention of construction accidents according to the chronological changes and social demand, but various problems have been pointed out. The biggest problem is that the safety management cost is earmarked very low because other items of safety management costs except for the safety inspection are not appropriately included in the actual construction site. Furthermore, it has been pointed out that it is difficult to settle the orderer due to the lack of specific use criteria. Therefore, in order to secure the proper safety management cost, this study is to estimate the actual cost by using of specification, quantity, material cost, labor cost for each type of the safety management item The results of this study were compared with the 71 cases of safety management costs in the safety management plan. In addition, analysis of unclear or unnecessary items in the current safety management cost and criteria and suggestions for improvement are provided. It is hoped that the results of this study will contribute to the rational safety management rate calculation.

• Health Policy and Management
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• v.19 no.4
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• pp.98-120
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• 2009

The purpose of this study is to elicit preference for drug listing decision criteria and to estimate the ICER threshold in South Korea using the discrete choice experiment (DCE) method. To collect the data, a DCE survey was administered to a subject sample either educated in the principle concepts of pharmacoeconomics or were decision makers within that field. Subjects chose between alternative drug profiles differing in four attributes: ICER, uncertainty, budget impact and severity of disease. The orthogonal and balanced designs were determined through computer algorithm to take the optimal set of drug profiles. The survey employed 15 hypothetical choice sets. A random effect probit model was used to analyze the relative importance of attributes and the probabilities of a recommendation response. Parameter estimates from the models indicated that three attributes (ICER, Impact, Severity of disease) influenced respondents' choice significantly(p${\pm}$0.001). In addition, each parameter displayed an expected sign. The Lower the ICER, the higher the probability of choosing that alternative. Respondents also preferred low levels of uncertainty and smaller impact on health service budget. They were also more likely to choose drugs for serious diseases rather than mild or moderate ones. Uncertainty however is not statistically significant. The ICER threshold, at which the probability of a recommendation was 0.5, was 29,000,000 KW/QALY in expert group and 46,500,000 KW/QALY in industry group. We also found that those in our sample were willing to accept high ICER to get medication for severe diseases. This study demonstrates that the cost-effectiveness, budget impact and severity of disease are the main reimbursement decision criteria in South Korea, and that DCE can be a useful tool in analyzing the decision making process where a variety of factors are considered and prioritized.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.31-45
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• 2012

PURPOSES: In Korea, rapid maintenance of distressed concrete pavement is required to prevent traffic jam of the highway. Asphalt concrete overlay has been used as a general maintenance method of construction for aged concrete pavement. AC overlay on existing concrete pavements experience various early distresses such as reflection crack, pothole and rutting, due to different physical characteristics between asphalt overlay and existing concrete pavement. Bonded concrete overlay(BCO) is a good alternative since it has advantages that can reduce various distresses during the service life since overlay material has similar properties with existing concrete pavements. Recently, BCO which uses the ultra rapid harding cement has been applied for maintenance of highway. BCO has advantage of structural performance since it does monolithic behave with existing pavement. Therefore, it is important to have a suitable bond strength criteria for securing performance of BCO. Bond strength criteria should be larger than normal tensile stress and horizontal shear stress occurred by traffic and environmental loading at bond interface. Normal tensile stress and horizontal shear stress need to estimated for the establishment of practical bond strength criteria. METHODS: This study aimed to estimate the bond stresses at the interface of BCO using the three dimensional finite element analysis. RESULTS: As a result of this study, major failure mode and maximum bond stress are evaluated through the analysis of normal tensile stress and horizontal shear stress for various traffic and environmental load conditions. CONCLUSIONS: It was known that normal tensile stresses are dominated by environmental loading, and, horizontal shear stresses are dominated by traffic loading. In addition, bond failure occurred by both of normal tensile stresses and horizontal shear stresses; however, normal tensile stresses are predominated over horizontal shear stresses.

• Journal of Environmental Policy
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• v.11 no.3
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• pp.67-96
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• 2012

The Ministry of Environment in Korea has been promoting the urban stream restoration project for paved streams in cities as the restored Cheonggyecheon. As an elementary study for suggesting policy implications for the project, cost and benefit criteria for an ex-post analysis on the Cheonggyecheon project is suggested in this study. The ex-ante analysis were reviewed critically by focusing on the cost and benefit criteria. Ex-post analysis plan in this study is developed considering the standard guideline of pre-feasibility, the theory of cost-benefit analysis, and the review results. The costs for compensating lands, amending conflicts, researching rivers, and maintaining water quantity were also included. For the benefits, this study proposes to estimate the benefits with the assessment on naturalness of stream. The results are expected to contribute to increase the efficiency of the urban stream restoration project and evaluate the project to match better with the meaning of the river restoration.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1127-1136
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• 2003

Estimation of software project cost, effort and duration in the early stage of software development cycle is a difficult and key problem in software engineering. Most of models estimate the development effort using the function point that is measured from the requirement specification. This paper presents optimal team size and duration prediction based on function point in order to provide information that can be used as a guide in selecting the most Practical and productive team size for a software development project. We introduce to productive metrics and cost for decision criteria of ideal team size and duration. The experimental is based on the analysis of 300 development and enhancement software project data. These data sets are divide in two subgroups. One is a development project; the other is a maintenance project. As a result of evaluation by productivity and cost measured criteria in two subgroups, we come to the conclusion that the most successful projects has small teams and minimum duration. Also, I proposed that predictive model for team sire and duration according to function point size based on experimental results. The presented models gives a criteria for necessary team site and duration according to the software size.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.5
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• pp.524-534
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• 2004

Statement of problem: The meaning of the beauty has a little different nature according to a time, culture, and nation. Purpose : This study was undertaken to estimate the geometric esthetic criteria for Korean woman by analysis of facial photograph in a smiling. Material and methods: The facial photographs of 678 Korean beautiful woman were collected from Miss Korea candidates(from 1971 to 2003 year). The dento-facial composition was measured and analyzed geometrically on computer monitor using $Adobe^{(R)}$ $Photoshop^{(R)}$ 7.0. The statistical significance of the differences among the 4 decade groups was estimated by a $x^2$ test. Result : The Korean beautiful woman skewed the geometric characteristics such as the 'coincidence' (83.0%) between facial midline and dental midline, the 'normal' (96.9%) alignment and arrangement of upper anterior teeth. the 'average' (79.1%) position and 'upward' (53.4%) curvature of upper lip, the 'parallel' (85.7%) relationship between the lower lip and upper anterior incisal curvature, the 'touching' (49.9%) and 'not-touching' (44.8%) relationship between upper anterior incisor and towel lip, the 'first premolar' (54.1%) and 'second premolar' (38.9%) displayed in a smile, and the 'symmetry' (89.4%) of smile. There was statistical significance among the 4 decades in the respect of the upper lip curvature, the relationship between upper anterior incisor and lower lip, and the most posterior teeth displayed in a smile (p<0.05). Conclusion : The Korean beautiful woman showed similar results to the western esthetic criteria in the some respects and the tendency that the Korean woman had more active smiling recently.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.103-112
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• 1998

Nature-friendly river project has became common practice in Japan. In order to make it available for the conservation and rehabilitation of desirable water environment, water criteria for water environmental assessment must be established. Especially, the criteria estimating the effects on ecosystem in and around river should be constructed. In this paper, classification method for water quality has been developed using biological indices and applied to observed data in Honmyo River, Nagasaki, Japan. Modified PI method (BI') has been suggested and those of three most abundant species resulted effective estimate for an overall water quality with comparatively simple procedure. Extensive database management code was prepared for the comprehensive ecological monitoring of river basin, which includes various biota. That system enables easy access of all the ecological data for a dissemination of a sound and sustainable water environment. The result of this study could improve knowledge base, serve making consensus for citizens, and help river management plans. In Japan, citizen's realization and action are the most critical factor for nature-friendly river restoration project.

• The Korean Journal of Applied Statistics
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• v.29 no.4
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• pp.643-656
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• 2016

High dimensional data are frequently encountered in various fields where the number of variables is greater than the number of samples. It is usually necessary to select variables to estimate regression coefficients and avoid overfitting in high dimensional data. A penalized regression model simultaneously obtains variable selection and estimation of coefficients which makes them frequently used for high dimensional data. However, the penalized regression model also needs to select the optimal model by choosing a tuning parameter based on the model selection criterion. This study deals with the bias effect of LASSO regression for model selection criteria. We numerically describes the bias effect to the model selection criteria and apply the proposed correction to the identification of biomarkers for lung cancer based on gene expression data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.563-569
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• 2020

Presenting the impact of meteorological disasters departs from the traditional weather forecasting approach for meteorological phenomena. It is important to provide impact forecasts so that precautions against disruption and damage can be taken. Countries such as the United States, the U.K., and France already conduct impact forecasting for heavy rain, heavy snow, and cold weather. This study improves and applies forecasts of the impact of heavy rain among various weather phenomena in accordance with domestic conditions. A total of 33 impact factors for heavy rain were constructed per 1 km grids, and four impact levels (minimal, minor, significant, and severe) were calculated using standard normal distribution. Estimated criteria were used as indicators to estimate heavy rain risk impacts for 6 categories (residential, commercial, utility, community, agriculture, and transport) centered on people, facilities, and traffic.