Smooth Fitting by Means of Genetic Programming

Yeun, Yun-Seog 대진대학교 신과학연구소 1999 신과학연구 Vol.2 No.-

This paper deals with the smooth fitting problem under the genetic programming(GP) algorithm. To reduce the computational cost required for evaluating the fitness value of GP trees, numerical weights of GP trees are estimated by adopting both linear associative memories and the Hook & Jeeves method. the quality of smooth fitting is critically dependent on the choice of the regularization parameter. So, we present a novel method for choosing the regularization parameter. Tow numerical examples are given with the comparison of generalized cross-validation B-splines.

바닥 가진 시 PH15-7Mo 브라켓 진동 피로 파괴에 따른 모달 파라미터 추정

강다솜(Da Som Kang),김선민(Seonmin Kim),배승훈(Seung-Hoon Bae),조대원(Dae-Won Cho),김대환(Dae-Hwan Kim),박태국(Tae-Kook Park),백승훈(Seunghun Baek),양민혁(Minhyeok Yang),도승환(Seunghwan Do) 한국소음진동공학회 2023 한국소음진동공학회 논문집 Vol.33 No.6

In this study, a method for estimating modal parameters (natural frequency, damping ratio, mode shape) in vibration fatigue testing of brackets with base excitation is proposed. The circle fitting method was used to estimate the damping ratio from the acceleration transmissibility without considering external forces. The transmissibility equation was approximated and converted to a circular equation, and the center of the circle was found to be determined by the modal parameters. The experimental results showed that the damping and natural frequency changed rapidly following significant changes in the center of the circle representing the system; the change in the mode can be estimated. The proposed method allowed for estimation of the modal parameters without force measurement during the vibration test.

Accuracy of linear approximation for fitted values in nonlinear regression

Kahng, Myung-Wook The Korean Data and Information Science Society 2013 한국데이터정보과학회지 Vol.24 No.1

Bates and Watts (1981) have discussed the problems of reparameterizing nonlinear models in obtaining accurate linear approximation confidence regions for the parameters. A similar problem exists with computing confidence curves for fitted values or predictions. The statistical behavior of fitted values does not depend on the parameterization. Thus, as long as the intrinsic curvature is small, standard Wald intervals for fitted values are likely to be sufficient. Accuracy of linear approximation for fitted values is investigated using confidence curves.

Accuracy of linear approximation for fitted values in nonlinear regression

강명욱 한국데이터정보과학회 2013 한국데이터정보과학회지 Vol.24 No.1

Bates and Watts (1981) have discussed the problems of reparameterizing nonlinear models in obtaining accurate linear approximation confidence regions for the parameters. A similar problem exists with computing confidence curves for fitted values or predictions. The statistical behavior of fitted values does not depend on the parameterization. Thus, as long as the intrinsic curvature is small, standard Wald intervalsfor fitted values are likely to be sufficient. Accuracy of linear approximation for fitted values is investigated using confidence curves.

AN EXPONENTIALLY FITTED METHOD FOR TWO PARAMETER SINGULARLY PERTURBED PARABOLIC BOUNDARY VALUE PROBLEMS

Gemechis File Duressa,Tariku Birabasa Mekonnen Korean Mathematical Society 2023 대한수학회논문집 Vol.38 No.1

This article devises an exponentially fitted method for the numerical solution of two parameter singularly perturbed parabolic boundary value problems. The proposed scheme is able to resolve the two lateral boundary layers of the solution. Error estimates show that the constructed scheme is parameter-uniformly convergent with a quadratic numerical rate of convergence. Some numerical test examples are taken from recently published articles to confirm the theoretical results and demonstrate a good performance of the current scheme.

New Metal Fitting Geometry and Optimization of the Swaging Parameters for an Automobile Power Steering Hose

S. R. HAN,J. H. CHOI,J. S. KWAK 한국자동차공학회 2012 International journal of automotive technology Vol.13 No.4

To solve the power steering (PS) hose oil leakage problem in automobile applications, a new geometry design of the metal fitting is required, and the swaging conditions applied to the PS hose should be optimized. In this study, a new metal fitting geometry for the PS hose was proposed. A CAE simulation for both the proposed and the conventional metal fittings was conducted, and both the stress and the strain in the PS hose were compared. An experimental verification was also performed with these two different metal fittings. Additionally, the swaging conditions were optimized by the durability cycle time, which was measured in an impulse test of the swaged PS hose. For a more economical production, practical working conditions were also recommended and experimentally verified.

유리함수 근사를 이용한 등가회로 모델링

백현,고재형,김군태,김형석 한국정보통신설비학회 2009 정보통신설비학회논문지 Vol.8 No.1

16주간 스피닝 운동이 여중생의 신체조성, 체력 및 혈중지표에 미치는 효과

윤장근(Yoon, Janf-Gun),이광희(Lee, Kwang-Hee),류현승(Rhyu, Hyun-Seung) 한국웰니스학회 2018 한국웰니스학회지 Vol.13 No.2

본 연구는 16주간의 스피닝 운동프로그램이 여중생의 신체조성, 체력, 혈중 지표에 미치는 효과를 분석하기 위하여 실시하였다. 본 연구는 여중생 20명(스피닝 사이클 그룹 10명, 통제그룹 10명)을 대상으로 진행하였다. 스피닝 사이클 그룹에게는 16주간 주당 3회, 방과 후 1시간 씩 운동프로그램을 진행 하였고, 통제그룹은 별도의 운동프로그램을 진행하지 않았다. 본 연구는 16주간의 운동 프로그램 실시 전과 후에 신체조성, 체력(1,200m 달리기, 윗몸일으키기, 배근력, 체전굴, 사이드스텝), 그리고 혈중지표(Total cholesterol, Low Density lipoprotein cholesterol, Glucose)를 측정하여 다음과 같은 결과를 도출하였다. 스피닝 사이클 그룹의 경우, 16주 후에 체지방률에서 유의한 감소가 나타났고, 체력에서는 1,200m 달리기, 배근력, 체전굴 에서는 유의한 증가가 나타난 반면 윗몸일으키기, 사이드스텝에서는 변화가 나타나지 않았다, 그리고 혈중지표에서는 TC, LDL-C, 항목에서 유의한 감소를 나타냈으나 Glucose 에서는 유의한 차이가 나타나지 않았다. 통제군에서는 신체조성, 체력, 혈중지표 모두에서 유의한 차이는 나타나지 않았다. 결과적으로 여중생의 경우 스피닝 사이클 운동을 통하여 신체조성과 체력, 그리고 혈중지표에 긍정적인 영향을 주며, 청소년 비만예방과 건강관리, 그리고 발육발달에 긍정적인 영향을 줄 수 있다는 결과를 보여주었다. This study was conducted to analyze the effects of 16 weeks spinning exercise program on body composition, physical fitness, and blood parameters of middle school girls. This study was conducted on 20 middle school girls students(10 spinning cycle groups and 10 control groups). The spinning cycle Group conducted an exercise program three times per week for 16 weeks and one hour after school, and the control group did not perform a separate exercise program. The purpose of this study was to measure body composition, physical fitness (1,200 m running, sit up, back muscle strength, Sit and reach, side step), and blood parameters(Total cholesterol, low density lipoprotein cholesterol, Glucose) The results are as follows. In the spinning cycle group, there was a significant decrease in body fat percentage after 16 weeks. In the physical fitness, there was a significant increase in 1,200m running, back muscle strength, and sit and reach, but no change in sit up, side step. There was a significant decrease in TC, LDL-C, but there was no significant difference in glucose. In the control group, there was no significant difference in body composition, physical fitness, and blood parameters. As a result, it was shown that the spinning exercise positively affects body composition, physical fitness, and blood parameter, and can positively affect the prevention of obesity, health care, and development of adolescents.

운동유형별 뇌졸중 환자의 기능적 수행능력 변화 2: 활동체력 및 보행변수 분석

박성현(SungHyunPark) 한국체육학회 2008 한국체육학회지 Vol.47 No.3

본 연구는 운동유형별 운동 전후 뇌졸중 환자의 활동체력 및 보행변수를 비교하여 기능적 수행능력의 증진을 위한 효과적인 근력강화 방법을 제시하는데 그 목적이 있다. 이를 위하여 뇌졸중 환자 총 21명을 대상으로 운동치료군 7명, 탄성밴드군 7명 및 신장반사군 7명의 세 집단을 구성하여 8주 동안 주 5회의 운동프로그램을 실시하였다. 이에 대한 자료 검증을 위해 반복측정에 의한 이원변량분석을 실시하여 다음의 결론을 얻었다. 첫째, 활동체력의 변화는 244cm 왕복 걷기에서 신장반사군이 운동 전보다 운동 후에 향상되었다. 둘째, 보행변수의 변화는 보행속도와 활보장에서 운동 후에 신장반사군이 운동치료군과 탄성밴드군보다 향상되었다. 결론적으로 신장반사 운동은 운동치료와 탄성밴드를 이용한 근력강화 운동보다 활동체력에서 동적 평형성과 민첩성, 보행변수에서 보행속도와 활보장을 향상시키는데 효과적인 방법인 것으로 나타났다. The purpose of this study was to compare and analyze the effects of exercise types on physical fitness and gait parameter in stroke patients. For the purpose, the subjects of this study were classified into three groups, the first group was 7 therapeutic exercise group, the second group was 7 elastic band group, and the last group was 7 stretch reflex group. The three exercise programs were 5 times a week for 8 weeks. The results were analyzed by two-way ANOVA with repeated measure. The results were as follows; At first, the stretch reflex group improved 244cm up and go after the exercise program in physical fitness. At second, the stretch reflex group revealed higher in gait velocity and stride length than the therapeutic exercise group and elastic band group after the exercise program in gait parameter. In conclusion, stretch reflex exercise revealed 244cm up and go in physical fitness, and to gait velocity and stride length in gait parameter than therapeutic exercise group and elastic band group were positive effects.

The daily computed weighted averaging basic reproduction number R_0,k,ωⁿ for MERS-CoV in South Korea

Jeong, D.,Lee, C.H.,Choi, Y.,Kim, J. North-Holland Pub. Co 2016 PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIO Vol.451 No.-

<P>In this paper, we propose the daily computed weighted averaging basic reproduction number R-0,k,omega(n) for Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak in South Korea, May to July 2015. We use an SIR model with piecewise constant parameters beta (contact rate) and gamma (removed rate). We use the explicit Euler's method for the solution of the SIR model and a nonlinear least-square fitting procedure for finding the best parameters. In R-0,k,omega(n), the parameters n, k, and w denote days from a reference date, the number of days in averaging, and a weighting factor, respectively. We perform a series of numerical experiments and compare the results with the real-world data. In particular, using the predicted reproduction number based on the previous two consecutive reproduction numbers, we can predict the future behavior of the reproduction number. (C) 2016 Elsevier B.V. All rights reserved.</P>