• Quantitative Bio-Science
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• 제37권2호
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• pp.133-141
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• 2018

Graphical lasso is one of the most popular methods to estimate a sparse precision matrix, which is an inverse of a covariance matrix. The objective function of graphical lasso imposes an ${\ell}_1$-penalty on the (vectorized) precision matrix, where a tuning parameter controls the strength of the penalization. The selection of the tuning parameter is practically and theoretically important since the performance of the estimation depends on an appropriate choice of tuning parameter. While information criteria (e.g. AIC, BIC, or extended BIC) have been widely used, they require an asymptotically unbiased estimator to select optimal tuning parameter. Thus, the biasedness of the ${\ell}_1$-regularized estimate in the graphical lasso may lead to a suboptimal tuning. In this paper, we propose a two-staged bias-correction procedure for the graphical lasso, where the first stage runs the usual graphical lasso and the second stage reruns the procedure with an additional constraint that zero estimates at the first stage remain zero. Our simulation and real data example show that the proposed bias correction improved on both edge recovery and estimation error compared to the single-staged graphical lasso.

• 간호행정학회지
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• 제6권2호
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• pp.195-209
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• 2000

The purpose of this study is to estimate the population requiring nursing home services among elderly people in Korea. This study identifies the need of nursing home services determined by health care professionals and estimates the proportion of elderly people requiring nursing home service according to the admission criteria. Surveys were conducted on health care professionals including medical doctors, home care nurses, and nurse practitioners. They were asked to assess nursing home need based on four content areas: Physical function (Activities of Daily Living), chronic disease, Physical symptoms (incontinence), mobility, eating, and sensory function. Based on the professionally determined need criteria the proportion of elderly people requiring nursing home services was estimated using secondary data from the 1994 Survey on the Living Status of the Korean Elderly. The number of study subjects to estimate nursing home need who were 60 and older totaled 2,058. The most important factor contributing to the admission eligibility criteria was the elderly living alone. Other factors related were the elderly being unable or having difficulty carrying out activities, and having insufficient help from other our activities, and having insufficient help from other members of the household. Using only physical function, the proportion of elderly people requiring nursing home was $8{\sim}9%$. When only chronic disease was used, proportions varied widely; for the doctor's group, the proportion was over 30%. Using all areas, the proportions of elderly people requiring nursing home were between 13% and 38%. The estimate using chronic disease and physical function was similar to the on using all areas.

• 상하수도학회지
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• 제23권6호
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• pp.865-870
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• 2009

In this study, the adequacy of Reynolds numbers and Froude numbers derived from about sixty domestic water treatment plants (WTPs) were analyzed in order to estimate the characteristics of hydraulic behavior within the rectangular shaped sedimentation basins used widely. From the results of analysis, most of domestic WTPs have satisfied the criteria regulated as that Reynolds number should less than 1,000(dimensionless). On the other hand, they have not been able to satisfy the Froude number criteria, which should be higher than $1.0{\times}10^{-6}$. The reasons why most of domestic WTPs could not satisfy the criteria are that its criteria basis has been not only inadequate, but also the concept of external flow occurred around a settling particle has been ignored. Accordingly, this study proved the feasibility of Archimedes number, which indicates the ratio between particle Reynolds number and Froude number, to evaluate the hydraulic efficiency and its function of scale factor.

• 대한가정학회지
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• 제33권6호
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• pp.43-59
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• 1995

the purposes of this study were to ecamine mother's perception for the quality criteria of day care center, and to estimate the differences of these according to the demographic characteristics, For these purposes, the data were collected by using questionnaire distributed to 568 mothers with children enrolled in day care center be located in Taegu. The data were analyzed by frequency, percentage, F-test, Scheffe test, regression analysis. The major findings of this research were as follows : 1. Generally, there were significant differences in the mother's perception for the quality criteria of day care center according to the demographic characteristics. 2. Among the independent variables, mother's educational level had significant influences on the all domains of mother's perception for the quality criteria of day care center.

• 한국정밀공학회지
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• 제21권6호
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• pp.179-187
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• 2004

In this study, for a safety assessment of wheelchair occupant in frontal and side impact of wheelchair loaded vehicle, a sled impact test was perfumed. Each test was carried out total 6 times, by using Hybrid III 50th-percentile male dummy in light weight and electric wheelchair. We estimate MC(Motion Criteria), CIC(Combined Injury Criteria), HIC(Head Injury Criteria), HNIC(Head and Neck Injury Criteria) based on measured data. Through this study, we make an assessment of risk analysis of wheelchair occupant and wheelchair. Through this study, safety standard of wheelchair is to be evaluated.

• Nuclear Engineering and Technology
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• 제43권5호
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• pp.437-446
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• 2011

Siting criteria for nuclear power plants require that faults be characterized as to their potential for generating earthquakes, or that the absence of the potential for these occurrences be demonstrated. Because the definition of active faults in Korea has been applied by the deterministic method, which depends on the numerical age of fault movement, the possibility of inherent uncertainties exists in determining the maximum earthquake from the fault sources for seismic design. In an attempt to overcome these problems this study suggests new criteria and a probabilistic quantitative diagnostic procedure that could estimate whether a fault is capable of generating earthquakes in the near future.

• 대한영양사협회학술지
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• 제8권4호
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• pp.372-386
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• 2002

The purposes of this study were to find factor which influence on the selection criteria of food supplier. Questionnaire were distributed to 52 general hospitals with more than 400 beds located in Seoul and Kyongin province, and responded questionnaires were collected from 44 dietetic departments (84.6%) and 18 purchasing departments (34.6%). The main results of this study can be summarized as follows: (1) supplier selection criteria include quality, service, cost and supplier competency. (2) With having been met with tight competition and market opening, hospitals plan a strategy to improve quality, service and they tend to have more interest in various supplier selection criteria. (3) Purchasing departments estimate more highly the rate of reflection in considering supplier selection criteria than the rate of importance about cost criteria, which reveals that purchasing departments sensitively respond to cost cutdown. (4) When selecting suppliers, a significant(p<.01) influence of stability of supplier industry environment on the selecting criteria such as the importances of quality, service, and supplier quality are recognized only after recognizing the stability of food delivery industry. Food supplier industry secures stability more quickly through major companies' participation in food distribution industry and this will reveal the importance of supplier selection criteria. (5) Suppliers which are selected by the quality criteria, service criteria, supplier quality criteria make efforts to communicate with foodservice departments, to give more proper information about substitute food, new product, and to make commitments, while suppliers which are decided by cost criteria do not establish supportive relationships with foodservice departments.

• 한국농공학회지
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• 제40권3호
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• pp.35-41
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• 1998

Cost estimate system Will be changed from the prime. cost calculation to the historical cost data because the present system has some problems. In this situation, each owner should prepare his own cost estimate system based on the historical cost data. In this study, the standard work items were classified and the criteria of their work amount computation were established for rural improvement projects. And also the historical cost data were collected in all range of rural improvement projects, and the database system, "HICOMS" (HIstorical COst data Management System) was built. In order to test the applicability of the HICOMS, standard work cost and contractor cost were compared. The results by HICOMS showed high significance and it was concluded that the HICOMS could be applicable for the cost estimate of the rural improvement projects. projects.

• 한국안전학회지
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• 제16권3호
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• pp.53-60
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• 2001

This paper presents a graphical method for hazard assessment of electric shock by safety criteria. For the human body to be safety actual body current should not exceed safety criteria, i.e. allowable body current. The assessment method presented in this paper is based m the safety criteria of the IEEE Standard 80 as well as the IEC 479-1. The hazard can be assessed in terms of alterable touch voltages instead of alterable body current. Thus, the hazard assessment of given electric shock condition is referred to a procedure by which the actual touch voltages are compared with the allowable (safe) touch voltages. Since the IEC 479-1 safety criteria are nonlinear, the graphical method is presented for the hazard assessment. Body current and body voltage are calculated with the allowable touch voltage. A comparison of the safety criteria of two widely accepted standards, i.e. the IEEE Std 80 End the IEC 479-1 is proposed. Also Thevenin equivalent resistance is obtained from electric shock model expressed by two-port earth-grid-foot system. On the basis of calculated results, the allowable touch voltage, the body current and the body voltage we can conduct the hazard or safety assessment and estimate the severity of electric shock.

• 농촌계획
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• 제28권1호
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• pp.27-35
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• 2022

This study aims to establish the indicator system of the quality of life of rural residents and to estimate the weights among criteria or sub-criteria that constitute the indicator system of the quality of life using AHP(Analytic Hierarchy Process) method. Indicator system consists of four criteria, that is, health care, eduction & culture, living environment, and income and jobs. Each criterion include three sub-criteria that make up corresponding criterion. The results show that income and jobs was most highly evaluated among the four criteria. It was followed by health care, living environment, and eduction & culture. Among the total 12 sub-criteria, annual income was most highly evaluated, followed by medical service level, job satisfaction, and public transportation environment in terms of global weight which was deduced from expert questionnaire survey. This study implies that rural development policy needs to focus on increasing rural residents' income by creating good quality occupations and increasing the level of medical services, and expanding public transportation services in rural areas. This study has failed to collect local residents' opinions regarding their quality of life in spite of the efforts to reflect the opinions from various expert groups, which is the limitation of this study.