• 자원환경지질
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• 제40권6호
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• pp.751-759
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• 2007

황해 군산분지의 지하 지질구조를 파악하기 위하여 인공위성 해면고도계 중력자료를 이용하여 파워 스펙트럼 분석(power spectrum analysis) 방법으로 밀도 불연속면의 평균 깊이를 계산하였다. 계산 결과에 의하면 군산분지를 포함한 본 연구지역에서는 각각 -1.1km, -3.4km, -9.1km 그리고 -31.0km의 평균 깊이를 가지는 밀도 불연속면이 검출되었다. -1.1km 평균 깊이의 밀도 불연속면은 본 연구지역의의 탄성파 단면에서 관찰되는 왕복 주시 1초 부근에서 나타나는 광역 부정합면으로 해석되었고, -3.4km 평균 깊이의 밀도 불연속면 또한 탄성파 단면에서 인지되는 음향기반암 상부면과 일치하는 것으로 해석되었다. -9.1km 평균 깊이의 밀도 불연속면은 본 연구지역의 시추공 자료, 탄성파 단면, 광역 지질 등을 고려하여 화성기원 기반암의 상부면으로 해석하였다. 이는 본 연구지역의 음향 기반암층은 기존의 연구에서 고려 대상이 되지 않았던 퇴적암으로 이루어져 있음을 의미한다. -31.0km의 평균 깊이를 가지는 밀도 불연속면은 일반적인 대륙지각의 평균 두께와 유사한 값을 보이므로 모호면으로 해석하였다. 화성기원 기반암 상부면으로 해석된 -9.1km 평균 깊이의 밀도 불연속면의 검출은 군산분지의 석유 가스 부존 가능성에 관한 연구에 있어 기존의 연구보다 심부층(음향 기반암층)에 대한 연구가 필요함을 시사하였다.

• 대한수학회보
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• 제48권4호
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• pp.725-736
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• 2011

By using the Lyapunov functional method, stochastic analysis, and LMI (linear matrix inequality) approach, the mean square exponential stability of an equilibrium solution of uncertain stochastic Hopfield neural networks with delayed is presented. The proposed result generalizes and improves previous work. An illustrative example is also given to demonstrate the effectiveness of the proposed result.

• Industrial Engineering and Management Systems
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• 제16권1호
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• pp.22-43
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• 2017

It is urgently-needed to construct a green supply chain (GSC) from collection of used products through recycling of them to sales of products using the recycled parts. Besides, it is necessary to consider the uncertainty in product demand as a risk in a GSC. This study proposes the optimal operations for a GSC with a retailer and a manufacturer. A retailer pays an incentive for collection of used products from customers and sells a single type of products in a market. A manufacturer produces the products ordered by the retailer, using recyclable parts with acceptable quality and compensates the collection cost of used products as to the recycled parts. This paper discusses the following risk attitudes: risk-neutral attitude, risk-averse attitude, and risk-prone attitude. Using mean-variance analysis, the optimal decisions for product order quantity, collection incentive, and lower limit of quality level, in the decentralized GSC (DGSC) and the integrated GSC (IGSC) are made. DGSC optimizes the utility function of each member. IGSC does that of the whole system. The analysis numerically investigates how (i) risk attitude and (ii) quality of recyclable parts affect the optimal operations. Supply chain coordination between GSC members to shift IGSC from DGSC is discussed.

• Journal of the Korean Data and Information Science Society
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• 제8권1호
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• pp.99-109
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• 1997

The estimation procedure of mean residual life function has been placed an important role in the study of survival analysis. In this paper, the product limit estimator on left truncated and right censoring model is proposed with asymptotic properties. Also, the small sample properties are investigated through the Monte Carlo study and the proposed product limit type estimator is compared with ordinary Kaplan-Meier type estimator.

• 한국안광학회지
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• 제20권2호
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• pp.201-210
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• 2015

목적: Vision therapy 프로그램이 양안시기능 개선에 주는 효과를 통계적으로 종합하기 위하여 전체평균 효과크기, 종속변수별 평균 효과크기 그리고 대상특성과 처치특성에 따른 효과크기를 메타분석 기법을 이용하여 분석하고자 하였다. 방법: 자료의 분석을 위해 vision therapy 프로그램을 적용하고 그 효과를 분석한 국내 선행연구 14편을 선정하여 메타분석하였다. 결과: 전체평균 효과크기는 1.207로 높은 수준의 효과크기를 나타내었다. 양안시이상 유형별 하위영역의 평균 효과크기는 버전스 이상 그룹(2.989)이 가장 높았으며, 조절기능이상 그룹(0.868), 조절기능과 버전스 모두 이상이 있는 그룹(0.692) 순이었다. 대상특성에 따른 효과크기는 중복장애가 없는 양안시이상 그룹(2.509)을 대상으로 실시한 vision therapy가 가장 컸으며, 주당횟수별 평균 효과크기는 주당 7회의 처치 때 2.310으로 가장 큰 효과크기를 나타내었다. 그리고 처치기간에 따른 효과크기는 8주에서 2.019로 양안시기능 개선을 위한 vision therapy가 가장 효과적이었다. 결론: Vision therapy 효과에 대한 각각의 연구결과를 평균 효과크기로 변환하고 이를 객관화하는 방법을 통해 양안시기능 개선을 위한 치료가 효과적임을 증명할 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3299-3304
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• 2013

Background: The Global Adult Tobacco Survey has 15 key indicators, cigarettes smoked per day (CPD) among daily smokers being one of them. The first wave of GATS in 14 countries indicated that mean CPD use is higher in women than men in India only, which is contrary to the current understanding of tobacco use globally. This study was undertaken to understand the unusual findings for mean CPD use in the GATS-India survey. Materials and Methods: Items B06a and B06b of the GATS India survey questionnaire that collected information on daily consumption of manufactured and rolled cigarettes were analyzed using SPSS software. Exclusive users were identified from these items after excluding the concurrent users of other tobacco products. Cigarette type, exclusive use and gender stratified analyses were made. Consumption of different types of cigarettes among the mixed users of manufactured and rolled cigarettes were correlated. Results: Higher mean number of CPD use among male daily-smokers was observed than their female counterparts in product specific analysis. Mean CPD as per GATS cigarette definition was higher in males than females for exclusive users but a reverse trend was observed in case of non-exclusive users. Use of manufactured cigarettes increased with increase in use of rolled cigarette among the mixed users and around half of these users reported equal CPD frequency for the both types of cigarettes. Conclusions: The anomaly in mean CPD estimate in GATS-India data was due to inclusion of two heterogeneous products to define cigarettes, variation in cigarette product specific user proportions contributing to the average and non-exclusive concurrent use of other tobacco products. The consumption pattern of cigarettes among the mixed users highlights bias in CPD reporting. Definition, analysis and interpretation of 'cigarettes per day' in the GATS India survey need to be improved by redefining cigarettes and making product specific analyses.

• 한국농공학회논문집
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• 제47권6호
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• pp.15-24
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• 2005

The normalization on the characteristics of water level change at the upstream gauging station was attempted according to the operation of drainage sluice gate of the Geumgang estuary dam. The characteristics were normalized by the analysis of water level change and by the linear-regression of the water level data measured at the inner station of Geumgang estuary dam and upstream gauging station. The results of normalization may be referred to the management of Geumgang estuary lake, the operation of pumping and drainage stations in the shore of the lake. The mean response time of water level change on Ibpo, Ganggyeong and Gyuam water level station were 39,81 and 160 minutes, when sluice gate was opened respectively. The mean velocity of surface wave, the mean displacement of water level change, the mean time of water level change and the mean rate of water level change varied largely depending on the location of gauging station and the characteristics of stream section of the water level gauging station.

• 응용통계연구
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• 제23권2호
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• pp.317-323
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• 2010

Measures are very useful tools for comparing the shape variability in statistical shape analysis. For examples, the Procrustes statistic(PS) is isolated measure, and the mean Procrustes statistic(MPS) and the root mean square measure(RMS) are overall measures. But these measures are very subjective, complicated and moreover these measures are not statistical for comparing the shape variability. Therefore we need to study some tests. It is well known that the Hotelling's $T^2$ test is used for testing shape variability of two independent samples. And for testing shape variabilities of several independent samples, instead of the Hotelling's $T^2$ test, one way analysis of variance(ANOVA) can be applied. In fact, this one way ANOVA is based on the balanced samples of equal size which is called as BANOVA. However, If we have unbalanced samples with unequal size, we can not use BANOVA. Therefore we propose the unbalanced analysis of variance(UNBANOVA) for testing shape variabilities of several independent samples of unequal size.

• Journal of Korean Biological Nursing Science
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• 제21권4호
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• pp.239-248
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• 2019

Purpose: Postmenopausal women are a unique population with high risk for the degeneration of muscle. The aim of the present meta-analysis was to accurately evaluate the effects of vitamin D on muscular strength in postmenopausal women. Methods: A review was conducted using electronic databases, including PubMed, EMBASE, Ovid Medline, CINAHL complete, and the Cochrane Library from inception through 19 March 2019. Included studies were selected by two independent reviewers. The meta-analysis were performed using Review Manager 5.3 software. Results: A total of nine randomized controlled clinical trials were included in this review. Vitamin D interventions led to no changes in the upper limb muscle strength (mean difference -0.16, 95% CI: -1.09 to 0.77), lower body muscle strength (standard mean difference 0.08, 95% CI: -0.11 to 0.26), and back/hip muscle strength (standard mean difference 0.06, 95% CI: -0.05 to 0.17). Conclusion: Pooled results from eight studies indicated that supplementation of vitamin D did not increase muscle strength in postmenopausal women. Apparently, the present review suggests that supplementation of vitamin D alone had no didn't show any beneficial effects on muscle strength in postmenopausal women.

• 한국경영과학회지
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• 제35권3호
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• pp.59-68
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• 2010

Improving productive efficiency is important for strengthening a competitiveness of coastal fisheries. This paper examines the productive efficiency of a sample of coastal gillnet fishing business units by estimating a stochastic frontier analysis (SFA) and a data envelopment analysis (DEA) approaches and compares those estimates obtained from two approaches. The estimated mean productive efficiency by SFA is 77.6% and the mean productive efficiencies obtained for the VRS and CRS DEA are 75.9% and 45.7%, respectively. The joint use of SFA and DEA for estimating efficiency is also discussed.