• 디지털융복합연구
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• 제11권1호
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• pp.361-368
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• 2013

본 연구의 목적은 악성 및 양성 여성골반 병변에서 자기공명 확산강조영상의 정량적, 정성적평가을 통하여 최적의 확산경사계수(b-values) 값을 구하고, 임상적 유용성을 알아보고자 하였다. 확산강조영상의 b-value($s/mm^2$)값을 600, 800, 1000, 1200, 1400까지 변화시키면서 얻었다. 정량적 분석결과 b-values 값 중 800에서 자궁근종의 평균 신호대 잡음비 $84.6{\pm}4.57$(p=0.024) 와 대조도대 잡음비 $50.13{\pm}5.47$(p=0.028)로 가장 높았고, 자궁경부암의 평균 신호대 잡음비 $12.0{\pm}2.04$(p=0.047)와 대조도대 잡음비 $10.6{\pm}1.24$(p=0.001)로 가장 높았으며, 이때 현성확산계수는 자궁근종 $1.19{\times}10^{-3}$(p=0.008), 자궁경부암 $0.96{\times}10^{-3}$(p=0.027) 이었다. 정성적 분석결과로서 병변의 묘출도와 명확성은 $4.02{\pm}0.18$(p=0.028), $4.39{\pm}0.25$(p=0.015)로 800에서 가장 높았다. 결론적으로 확산강조 자기공명영상은 여성골반 병변 검출에 있어서 중요한 방법이고, 최적의 b-value($s/mm^2$)값은 $800s/mm^2$ 이었으며, 정량적, 정성적 평가는 여성골반의 악성 및 양성 감별진단에 도움을 주었다.

• 대한치과교정학회지
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• 제21권2호
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• pp.273-285
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• 1991

Crowded group is composed of 60 subjects who visited Yonsei University for orthodontic treatment and has no history of orthodontic treatment. Noncrowded group is composed of 26 subjects who has no crowding, considered to have a normal occlusion and no history of orthodontic treatment. Currently available and approved analytic method was used. Interrelationship between tooth size and arch size, and it's correlation on tooth crowding was studied and the following results were obtained. 1. In comparison of sum of mesiodistal width, of crown size of teeth was greater in noncrowded group than that of crowded group on both arch. (p < 0.01). 2. In comparison of arch lengths, the values measured from arch length 2 showed greater in noncrowded group (p < 0.01). Also in crowded group, arch length 1 showed greater value than arch length 2 on both arch (p < 0.01). 3. In comparison of arch widths, upper interlateral (p < 0.01) and upper intercanine width (p < 0.05) showed greater value in noncrowded group on upper arch and intermolar width showed greater value in noncrowded group on both upper and lower arches (p < 0.05). 4. In comparison of arch perimeters, arch perimeter 2 was greater value in noncrowded group on both upper and lower arches (p < 0.01). 5. Dentoalveolar disproportion was greater in noncrowded group on both upper and lower arches (p < 0.01). 6. In lower incisors MD/FL ratio, the central and lateral incisors were greater in crowded group, but statistial significance was only in lateral incisors (p < 0.01) 7. The irregularity index of lower incisors showed greater value in crowded group (p < 0.01).

• Journal of Platform Technology
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• 제6권1호
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• pp.9-16
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• 2018

최근에 이르러 많은 분석자들은 파이썬과 R 등을 이용하여 다양한 분석 및 통계를 효율적으로 사용하여 데이터를 분석하고 있다. 하지만 웹 시스템을 통하여 다양한 분석을 실시간적으로 표현 하고자 하는 요구 사항을 두가지 언어만을 이용하여 해결하기는 어렵다. 그리고 R 에서 P Value 등을 추출할 때 적합한 알고리즘을 적용하지만 Java 에서는 해당하는 알고리즘이 없거나 또는 해당 소스가 검증이 되지 아니하여 추출된 P-Value 값이 R 에서의 값과 다른 것을 확인 할 수 있다. 따라서 본 논문에서는 다른 언어에서 R 을 이용하여 분석자의 분석 알고리즘 내용을 바로 자신의 시스템에 적용 할 수 있는 방안을 제안하고자 한다.

• 한국식품영양학회지
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• 제26권4호
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• pp.919-927
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• 2013

Social commerce is becoming an increasingly popular shopping method among college women students. This study focuses on the influence of the satisfaction lavels and repurchasing intentions by consumers for restaurant and food choices according to social commerce attributes. In this survey, 351 valid surveys are being used to test the hypothesized (183 users and 168 non-usesr within 6 months), in order to ensure validity and reliability. As a result, factors such as perceived value, product diversity & information, delivery, ordering convenience, site character, price competitiveness, time pressure, and real time information are all being found. Factors of perceived value (p<0.001), price competitiveness (p<0.001), product diversity & information (p<0.05), delivery (p<0.05), and site character (p<0.05) significantly influence the customer satisfaction rates. Factors of perceived value (p<0.001), price competitiveness (p<0.001), time pressure (p<0.001), and site character (p<0.01) significantly influence the repurchasing intentions. In addition, it has been found that the customer satisfaction rates significantly influence repurchase intentions.

• 신재생에너지
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• 제20권2호
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• pp.2-16
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• 2024

Various loads induced by marine environmental conditions, such as waves, currents, and wind, are crucial for the operation and viability of offshore wind power (OWP) systems. In particular, waves have a significant impact on the stress and fatigue load of offshore structures, and highly reliable design parameters should be derived through extreme value analysis (EVA) techniques. In this study, extreme wave analyses were conducted with various Weibull distribution models to determine the reliable design parameters of an OWP system suitable for the Ulsan area. Forty-three years of long-term hindcast data generated by a numerical wave model were adopted as the analyses data, and the least-squares method was used to estimate the parameters of the distribution function for EVA. The inverse first-order reliability method was employed as the EVA technique. The obtained results were compared among themselves under the assumption that the marginal probability distributions were 2p, 3p, and exponentiated Weibull distributions.

• Journal of applied mathematics & informatics
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• 제31권1_2호
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• pp.131-145
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• 2013

In this paper, we present an initial value technique for solving singularly perturbed differential difference equations with a boundary layer at one end point. Taylor's series is used to tackle the terms containing shift provided the shift is of small order of singular perturbation parameter and obtained a singularly perturbed boundary value problem. This singularly perturbed boundary value problem is replaced by a pair of initial value problems. Classical fourth order Runge-Kutta method is used to solve these initial value problems. The effect of small shift on the boundary layer solution in both the cases, i.e., the boundary layer on the left side as well as the right side is discussed by considering numerical experiments. Several numerical examples are solved to demonstate the applicability of the method.

• 한국물환경학회지
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• 제36권2호
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• pp.148-152
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• 2020

The quantitative accuracy of dry rehydratable film method was compared with the standard culture method to analyze the applicability of dry rehydratable film in the total aerobic bacteria test for water. The materials used in this study were 500 cases of water and were tested according to the Korean official test method for drinking water. The mean value of the total aerobic bacteria in plate count agar(PCA) and MC-Media Pad AC(MAC) were 2.6 ± 1.1 Log cfu/mL and 2.6 ± 1.2 Log cfu/mL. The p value and correlation coefficient(R²) were 0.933 and 0.9985 between the PCA and MAC, respectively, indicating no significant difference and very high correlation. According to the water types, the p value and R² were 0.887 and 0.9911 in the PCA and MAC. In the purified water, the p value was 0.973 and R² was 0.9934 in the PCA and MAC of other water. In each type of water, there were no significant differences between the PCA and MAC, and the correlation was very high. Thus, it is suggested that the MAC would be available for total aerobic bacteria test for water.

• Korean Journal of Mathematics
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• 제18권1호
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• pp.87-96
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• 2010

We consider the semilinear biharmonic equation with Dirichlet boundary condition. We give a theorem that there exist at least three nontrivial solutions for the semilinear biharmonic boundary value problem. We show this result by using the critical point theory, the finite dimensional reduction method and the shape of the graph of the corresponding functional on the finite reduction subspace.

• 충청수학회지
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• 제7권1호
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• pp.141-152
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• 1994

We consider a numerical scheme for solving a nonlinear boundary integral equation (BIE) obtained by reformulation the nonlinear boundary value problem (BVP). We give a simple alternative to the standard collocation method for the nonlinear BIE. This method consists of one conventional linear system and another coupled linear system resulting from an auxiliary BIE which is obtained by differentiating both side of the nonlinear interior integral equations. We obtain an analogue BIE through the perturbation of the fundamental solution of Laplace's equation. We procure the super-convergence of approximate solutions.

• 한국농공학회지
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• 제44권6호
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• pp.106-114
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• 2002

In this study, the results of a series of consolidation test for undisturbed Ariake clay in Japan were analyzed by three methods, e-log p (e: void ratio, p: consolidation pressure), log e-log p and n-log p (n: porosity). Moreover, the characteristics of each analysis method were studied. For undisturbed Ariake clay, the log o-Log p and the n-log p relationships can be found as two groups of straight lines of different gradients, but both the elastic consolidation and plastic consolidation regions of e-log p relationship are expressed as a curve. In this paper, the porosity of consolidation yield n$\_$y/, consolidation yield stress p$\_$y/, and the gradient of the plastic consolidation region C$\_$p/ were represented by the log e-log p method, and n$\_$c/, P$\_$cn/ and C$\_$cn/ were represented by the n-log p method. The meaning and the relationships of each value were studied, and the interrelationships among compression indices i.e. C$\_$cn/, C$\_$p/ and C$\_$c/ are obtained from each analysis method as a function of initial porosity n$\_$0/.