가솔린 엔진에서 급가속 운전시 노킹 측정 및 분석

이종화(Jonghwa Lee),박경석(Kyungsuk Park),김현용(Hyunyong Kim) 한국자동차공학회 1999 한국 자동차공학회논문집 Vol.7 No.9

In this study, investigation of transient knock characteristics in a spark-ignition engine has been carried out. The universal knock threshold values were found by a DFDD method and a NSDBP method which is a non-dimensional version of the SDBP method. Also modified NSDBP method could be used for transient knock detection.<br/> In a commercial ECU, spark timing was retarded from the steady-state spark timing during rapid throttle opening to avoid uncomfortable feeling and knock. Knock usually occurred just after the start of rapid throttle opening when spark timing was set as values for the steady state condition. We found that air/fuel ratio deeply involved with the knock during transient condition. Due to the difference of initial heat release rate, knock occurred more easily at rich air/fuel ratio than at lean air/fuel ratio.

시민의 복지태도와 나눔행동에 관한 연구: 기부와 자원봉사 참여를 중심으로

이종화(Jonghwa Lee),장재혁(Jaehyuck Jang),한민희(Min Hee Han) 연세대학교 사회복지연구소 2019 한국사회복지조사연구 Vol.60 No.-

본 연구의 목적은 시민의 복지태도가 나눔행동에 미치는 영향력을 확인하는 것이다. 이를 위해 서울시와 서울연구원이 서울시 거주 3,019가구를 조사한 2015 서울복지실태조사 데이터를 활용해 시민들이 가진 4가지 복지태도 : 성장과 분배, 선택적 복지와 보편적 복지, 복지지출에 대한 개인과 정부의 책임, 정부복지정책 신뢰수준이 기부와 자원봉사 참여에 미치는 영향을 확인하였다. 분석방 법으로는 두 개의 이항종속변수 사이에 존재할 수 있는 상호의존성을 반영해 효율적인 추정을을 가능하게 해주는 이변량 프로빗 모형을 사용하였다. 연구결과 성장보다 분배를 중요하게 인식할수 록, 정부복지정책에 대한 신뢰가 높을수록 기부에 적극적으로 참여하였고, 복지지출에 대한 정부의 책임을 중요하게 인식할수록 기부에 소극적인 것으로 나타났다. 그리고, 보편적 복지 정책에 대한 중요성 중요하게 인식할수록 자원봉사 참여에 소극적인 것으로 나타났다. 본 연구는 연구의 성과가 부족한 복지에 대한 개인 인식과 나눔 행동 사이의 관계에 대해 실증적인 분석을 하였고, 기부와 자원봉사 행동에 대한 상호의존성을 반영할 수 있는 분석방법을 소개했다는 점에서 의의를 갖는다. The purpose of the study is to identify the influence that the citizen’s attitude of welfare exerts on philanthropic behaviors. Specifically, the study has identified the influences that the citizen’s attitude on the four things, that is, growth and distribution, targeted welfare and universal welfare, the responsibility for welfare expenses, and the trust in the governmental welfare policy, exert on donations and participation in volunteer work. For this purpose, the study used the data from the 2015 Seoul Welfare Survey which was conducted with 3,019 households in Seoul. And for its analytical method, the study employed Bivariate Probit model which enables efficient estimation by reflecting the interdependence that may exist between the two binomial dependent variables. The study showed that people who consider welfare distribution more importantly than economic growth and those who put greater trust in the governmental welfare policy more actively participated in donation, and that those who more strongly believe the governmental responsibility for welfare were more passive in participating in donation, and that those who more strongly believe the importance of universal welfare policy were more passive in participating in volunteer activities. This study has performed an empirical analysis on the relationship between the public perception of welfare and philanthropic behaviors and is significant in that it has introduced a new analytical method that can reflect the interdependence between donation and volunteer participation.

접촉력 추정 정확도 향상을 위한 보행로봇의 마찰 토크 추정

이종화(Jonghwa Lee),강한구(Hangoo Kang),이지홍(Jihong Lee),전봉환(Bong-Huan Jun) 한국해양공학회 2015 韓國海洋工學會誌 Vol.29 No.5

This paper introduces a method to estimate the contact-force of the leg of a walking robot and proposes a solution to a shortcoming of the previous study. This shortcoming was the deteriorating performance when estimating the contact-force whenever the rotation of each joint was reversed. It occurred because the friction-torque of each joint was not considered. In order to solve this problem, a friction-torque model for a robot leg was developed based on repetitive experimentation and used improve the contact-force estimation performance. We verified the performance of the proposed method experimentally.

아나목스 그래뉼를 이용한 질소 및 과불화화합물의 동시 제거

이종화(Jonghwa Lee),장희원(Heewon Jang),박지원(Jiwon Park),임채영(Chaeyoung Lim),조상열(Sangyeol Jo),박준규(Jungyu Park) 대한환경공학회 2022 대한환경공학회 학술발표논문집 Vol.2022 No.11

줄넘기 시 템포가 협응에 미치는 영향

이종화(Lee, Jonghwa),현하경(Hyun, Hakyung),김영호(Kim, Youngho) 한국체육과학회 2022 한국체육과학회지 Vol.31 No.5

The purpose of this study was to compare and analyze the effect of tempo on coordination during jump rope. Thirty healthy adult males participated. The task was to jump rope single under with both feet synchronize with metronome tempo(80, 100, 120, 140, 160 bpm). The joint angles and angular velocities of wrist, elbow, shoulder, hip, knee, and ankle were calculated using data stably performed 5 times consecutively among the data performed 10 times in a row synchronize with metronome tempo. And angle-angle diagram, phase plane portraits, and correlation analysis were analyzed using each joint angle and angular velocity. The results of this study were as follows: First, The angle-angle diagrams show that the joint angles decrease as getting faster the tempo. In the wrist-shoulder and hip-ankle diagrams, coupled coordination was observed as getting faster the tempo. Second, In the phase plane portraits, the angular-angular velocity of all joints showed a convex shape. As getting faster the tempo, the angular velocities of the shoulders, hips, and knees decreased. Third, Elbow-shoulder, hip-knee, knee-ankle, and hip-ankle correlation coefficients were high. It was found that the correlation coefficient of hip-knee and hip-ankle decreased as getting faster the tempo. In conclusion, Wrist, elbow, and ankle joints played a more important role in jumping rope than the shoulder, knee, and hip joints. And, When the tempo of jumping rope was 120 bpm or higher, a stable coordination pattern appeared, but when the jumping rope was slowed at a slow tempo, an unstable coordination pattern was observed.

가상현실 기반 중재가 뇌졸중 환자의 우울과 삶의 질에 미치는 영향에 대한 메타분석

이종화(Lee, Jonghwa),강수진(Kang, Soojin),김영호(Kim, Youngho) 한국체육과학회 2021 한국체육과학회지 Vol.30 No.6

The current study analyzed the effect of virtual reality-based intervention on depression and quality of life in stroke patients. Databases (National Assembly Library, DBpia, RISS, KISS) were searched to extract studies for meta analysis by using the PICOS framework. From this procedure, two dissertations and five journal articles were selected for the literature on the effect on depression, and four dissertations and three journal articles were selected for the literature on the effect on quality of life. The R program(ver.4.0.5) meta analysis package was used to calculate the effect sizes for depression and quality of life. Results using random-effects model indicated that the effect size of depression was -0.82 (95% CI=-1.29, -0.35), which was a large effect size, and also the effect size of quality of life was 1.12 (95% CI=0.56, 1.67), showing a large effect size. The current study concluded that virtual reality-based intervention has positive effect on depression and quality of life in stroke patients.

가스터빈 연소기 개발을 위한 구조적 안정성 평가

이종화(Jonghwa Lee),박성완(Sungwan Park),김은영(Eunyoung Kim),조문수(Moonsoo Cho) 한국추진공학회 2016 한국추진공학회 학술대회논문집 Vol.2016 No.12

태권도 수련의 유·무가 신체적 자기효능감에 미치는 영향에 대한 메타분석

이종화(Lee, Jonghwa),강수진(Kang, Soojin),김영호(Kim, Youngho) 한국체육과학회 2021 한국체육과학회지 Vol.30 No.2

The current study analyzed the effect of Taekwondo training on physical self-efficacy. For this purpose, four dissertations and four academic journals were selected for meta-analysis. The effect size of physical self-efficacy including sub-factors such as perceived physical ability and physical self-presentation confidence were analyzed. Statistical analysis was performed using the Review Manager Version 5.4(RevMan, The Cochrane Collaboration, Oxford, UK) provided by the Cochran Collaboration. As a result of meta-analysis of 8 studies using the random effect model, The overall effect size of physical self-efficacy was calculated as .58 (95% CI=.28, .87). And, The effect size of perceived physical ability was .74 (95% CI=.22, 1.26), which was a moderate effect size, but the effect size of physical self-presentation confidence was .42 (95% CI=.11, .73), showing a small effect size. In conclusion, it was derived that Taekwondo training is more effective for perceived physical ability than for physical self-presentation confidence.

A Meta-Analysis of Attitudes toward Doping among Korean Athletes

이종화(Jonghwa Lee),강수진(Soojin Kang),안도진(Dojin An),김영호(Youngho Kim) 대한운동학회 2024 아시아 운동학 학술지 Vol.26 No.1

OBJECTIVES The purpose of the current study was to conduct a meta-analysis to comprehensively analyze and identify research on doping attitudes studied in Korea. METHODS Twelve articles were selected for analysis by searching for ‘doping attitudes’ and ‘doping PEAS’ in Korean academic databases. The meta-analysis was conducted using the meta-analysis package in the R program (ver.4.3.2). RESULTS indicated that 12 literatures on Korean athletes’ doping attitudes revealed an average PEAS mean score of 37.20 (95% CI = 34.29, 40.11). Moreover, results found that 10 articles on gender differences in Korean athletes’ doping attitudes showed a small effect size of -0.23 (95% CI = -0.34, -0.12), and a significant difference (p < .0001), with that female had higher mean PEAS scores than males. Results indicated that 4 studies on the difference in doping attitudes based on doping experience were found to have publication bias, so we meta-analyzed two additional studies using a trim-and-fill algorithm and found a moderate effect size of -0.64 (95% CI = -1.23, -0.05), with a significant difference (p = .0343). Additionally, Korean athletes with doping experience had higher mean PEAS scores than those without doping experience. CONCLUSIONS This study suggests that attitudes may be important in predicting doping intentions or doping behavior.

ISO/IEC의 디지털 트윈 국제표준화 동향

이종화(Jonghwa Lee) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.11