파워테일게이트의 DC모터구동회로에 적용된 EMI 저감기법에 대한 연구

김영식(Yeongsik Kim),윤용수(Yongsoo Yoon),정훈(Hun Jung),공준호(Junho Gohng),이상호(Sangho Lee) 한국자동차공학회 2008 한국 자동차공학회논문집 Vol.16 No.1

니켈기 경질 용사코팅의 마모거동에 미치는 공정조건의 영향

김균택(Kyun Tak Kim),김영식(YeongSik Kim) 한국트라이볼로지학회 2010 한국윤활학회지(윤활학회지) Vol.26 No.3

This study investigated the effects of spray parameters on wear behavior of the Ni-based hard coatings fabricated by thermal spray process. The experiment was designed by an orthogonal array, the Ni-based hard coatings were fabricated according to this experimental design. The wear test was performed on these coatings using ball-on-disk wear tester. The ANOVA was used to analyze the effects of spray parameters on the wear rate of these coatings, as a result, oxygen gas flow and acetylene gas flow were determined as main factors effected on the wear rate. The effects of these two factors on wear behavior were observed by using SEM and EDX.

학업성취 수준이 학교적응에 미치는 영향 : 개별화 및 상호작용 수업방식의 조절효과를 중심으로

이은경(Lee, Eunkyung),김영식(Kim, Yeongsik),성하경(Sung, Hakyoung),리함옥(Li, Hanyu),김이경(Ee-gyeong Kim) 중앙대학교 한국인적자원개발전략연구소 2021 역량개발학습연구 Vol.16 No.3

본 연구는 학교 부적응 현상의 심각성에 대한 문제인식에서 출발하여 학교적응을 좌우하는 주요 변수로서 학업성취의 영향력을 규명하는 한편, 교사의 개별화 수업과 상호작용 수업방식이 두 변수 간 관계를 조절하는 효과가 있는지 밝히는 데 목적이 있다. 분석을 위해 한국교육종단연구 2013의 4차 연도(2016년) 중학교 2학년생 응답자료 가운데 결측치를 제외한 5,471명의 응답자료를 토대로, 기술통계, 단순 선형 회귀분석, 위계적 회귀분석, 조건부 효과 분석을 실시하였다. 연구 결과, 중학생의 학업성취 수준은 학교적응에 유의한 영향을 미치고, 교사들의 개별화 수업 및 상호작용 수업은 두 변수 간의 관계를 조절하는 효과가 있음을 확인하였다. 본 연구는 학교 부적응 현상을 이해하는 데 학업성취가 중요한 단서를 제공할 수 있고, 학생 개인의 특성에 주목하고 능동성을 촉진하는 교사들의 수업방식은 궁극적으로 중학생의 학교 부적응을 해소할 수 있는 수단이 될 수 있다는 것을 밝혀냈다는 데 의의가 있다. 연구결과를 토대로 모든 중학생들의 기초학력을 높이는 한편, 교사들의 개별화 수업 및 상호작용 수업 지원에 필요한 시사점을 제시하였다. This study seeks to find the root cause of the problem of middle students’ school maladjustment by analyzing the students’ academic achievements based upon the influence of school adjustment, and the moderating effects of individualized teaching and interactive teaching methods of teachers between two specific variables. Out of Korean Education Longitudinal Study 2013, the 4th(2016) data set, the responses of 5,471 middle students in grade 2 were analyzed excluding outliers. According to the results, the level of academic achievement of middle school students has a significant impact on school adjustment. Moreover, individualized teaching and the interactive instruction methods of teachers has a clear moderating effect between the two variables. In this study, the academic achievement of middle school students related to the influence of school adjustment. and Teachers instruction methods that pay more attention to students personalities were found to be the means to eliminate school maladjustment. Based on the results, while improving the basic academic achievement of all middle school students, it puts forward institutional recommendations that promote individualized teaching and the furthering of interactive teaching methods by instructors.

Worst Case 조건에서 모터 로터 위치 센서의 오차 보상에 대한 연구

이한준(Hanjun Lee),김영식(Yeongsik Kim),윤상원(Sangwon Yun),김관식(Kwanseek Kim),이혜원(Hyewon Lee) 한국자동차공학회 2023 한국자동차공학회 학술대회 및 전시회 Vol.2023 No.11

3-phase motors are the most widely applied actuators in the automotive industry. This paper deals with the Hall sensor method among various methods for tracking the rotor when controlling a motor. In particular, we focused on major devices that require ASIL-D fail-safe, such as brakes and steering systems. To satisfy ASIL-D, a dual die type Hall sensor is applied, and different voltages are applied to satisfy redundancy. Usually, when the positions of the rotor and Hall sensor are not aligned, an electrical angle error occurs between each die. In this paper, we studied a method to adjust the temperature and voltage to the worst case, check the influence through fault injection, and correct it.

행복 ( 공공 ) 기숙사 사업의 타당성 분석

문찬주(Moon, ChanJu),허광영(Heo, KwangYeong),김영식(Kim, YeongSik),정동욱(Jeong, DongWook) 한국교육재정경제학회 2017 敎育財政 經濟硏究 Vol.26 No.3

이 연구는 비용-편익 비율(B/C), 순현재가치법(NPV), 내부수익률(IRR)을 활용하여 8개 대학에서 시행예정인 행복(공공)기숙사 사업의 타당성 분석을 위해 설계 및 시공기간 2년, 운영기간 30년을 포함한 32년간의 비용-편익을 분석하였다. 이를 위해 행복기숙사 건립의 대안으로 민자기숙사 건립 방안을 설정하였고, 비용-편익 분석결과의 비교를 통해 행복기숙사 사업과 민자기숙사 사업 중, 어느 대안이 더 타당한 것인지 분석하였다. 또한 지역규모에 따른 효과를 살펴보기 위해 지역 별로 비용-편익 분석을 실시하였다. 마지막으로 민감도 분석을 위해 할인율, 기숙사수용률을 다르게 설정한 비용-편익 분석을 실시했다. 분석 결과는 다음과 같다. 첫째, 비용-편익 비율(B/C), 순현재가치법(NPV), 내부수익률(IRR) 추정결과, 행복기숙사 사업이 민자기숙사에 비해 비용 대비 편익이 더 큰 사업이었다. 둘째, 기숙사가 위치한 소재지 규모에 따른 비용-편익 분석결과, 서울시, 광역시, 시군 규모 순으로 행복기숙사 건립 방안의 비용 대비 편익이 큰 것을 확인하였다. 셋째, 기숙사 수용률에 따른 비용-편익 분석결과, 행복기숙사 사업이 완공이후, 30년간 기숙사 수용률이 60% 정도를 충족한다고 하더라도 비용 대비 편익이 더 큰 사업임을 확인할 수 있었다. 이러한 결과는 행복기숙사 사업이 민자기숙사에 비해 사회적 편익이 큰 사업임을 시사하는 동시에, 소재지역의 규모가 큰 곳일수록 사회적 편익이 큼을 의미한다. 또한 실제 운영과정에 있어, 기 숙사수용률이 60% 정도까지 낮아지더라도 안정적으로 운영이 가능한 사업임을 시사하는 바이다. The purpose of this study is to analyze the feasibility of the Happy(Public) Dormitory project to be implemented by eight universities using the cost-benefit ratio (B/C), net present value method (NPV), and internal rate of return (IRR). The analysis period is two years for the design period and 30 years for the operation period. As an alternative, we set up a private residence dormitory and compared the results of the cost - benefit analysis to find out which alternative is more appropriate among the happy dormitory project and the private dormitory project. In addition, cost - benefit analysis was conducted for each region to examine the effects of regional size. Lastly, for the sensitivity analysis, cost-benefit analysis was conducted with different discount rate and dormitory acceptance rate. The results of the analysis are as follows. First, cost - benefit ratio (B/C), net present value method (NPV) and internal rate of return (IRR) estimation result showed that the happy dormitory project was more cost - effective than the private dormitory. Second, the results of the cost - benefit analysis according to the size of the residence where the dormitory is located show that the cost - benefit ratio of the dormitory building in Seoul, metropolitan city is higher than small city. Third, as a result of the cost - benefit analysis according to the dormitory acceptance rate, it was confirmed that even though the dormitory acceptance rate of the dormitory is 60% after 30 years of completion. This result suggests that the happy dormitory project is a business with big social benefits as compared with the private dormitory, and the larger the area, the greater the social benefits. In addition, it suggests that it is a stable business even if the dormitory acceptance rate drops to around 60% in actual operation.

장시간 주행 허리 통증 예방을 위한 시트 Lower-Thoracic Support (LTS) 기술 개발

이백희(Baekhee Lee),곽민혁(Minhyuk Kwak),김영식(Yeongsik Kim),안성철(Sungcheul Ahn) 한국자동차공학회 2019 한국자동차공학회 부문종합 학술대회 Vol.2019 No.5

The present study analyzed effectiveness of seat lower-thoracic support (LTS) technology for fundamental prevention of low back pain in long-term driving. A LTS was applied to T10 ~ T12 spine area on seat back by integrating with air cell in-/deflation system. Spine posture bending rates of non-lumbar and LTS were measured and compared by applying a 5-step spine posture estimation method (S1. non-lumbar support spine posture measurement, S2. optimal/maximum LTS spine posture measurement, S3. marker projection to spine, S4. spine posture estimation, S5. spine posture bending rate calculation). Posture and comfort satisfactions of non-lumbar and LTS for one-hour driving were evaluated per 5 minutes by eight seat experts using questionnaire with ten-point scale (0: extremely dissatisfied, 5: moderate, 10: extremely satisfied). The LTS seat makes bended-spine posture maximum 44% erect compared to non-lumbar seat. Posture and comfort satisfaction of LTS were higher 1.5 ~ 2.8 times compared to those of non-lumbar. The LTS can contribute to making/maintaining erect-sitting posture for prevention of lower back pain in long-term driving.

해석을 통한 ECU EMC 성능 조기 개선 방안

정주용(Jooyong Jung),이찬호(Chanho Lee),김영식(Yeongsik Kim),양만영(Manyoung Yang) 한국자동차공학회 2013 한국자동차공학회 학술대회 및 전시회 Vol.2013 No.11

시트 오염의 로지스틱 판별 기술

이백희(Baekhee Lee),곽민혁(Minhyuk Kwak),김영식(Yeongsik Kim),안성철(Sungcheul Ahn) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6

The present study developed Logistic regression models for discrimination of seat stain degrees. Seat stains have been qualitatively evaluated by a tester using gray scale (G/S) chart (1 ~ 5 points), but quantification of seat stains is needed due to inter-tester variability (e.g., visual acuity, color preference) and intra-tester variability (e.g., condition, feeling). To quantify seat stain degree, a driver’s lower body shaped-seat stain machine was developed for considering real ingress/egress conditions. Seven leather seats and 14 fabric seats, selected for considering full coverage of Lab color space in seat color dimensions, were contaminated using soil cloth (E128), and were measured color difference (ΔE) using color-difference meter. Ninety six ordinal Logistic regression (logit model) model candidates were developed, and then optimal models for leather and fabric seat were selected considering discriminability for 4.5 ~ 3.5 of G/S and %concordant (leather: 95.2%, fabric: 96.7%). Logistic discriminant methods developed in the study can contribute to quantification of seat stain degrees and reduction of customer’s satisfaction.

용사법에 의해 제조된 Al/SiC 복합재료의 마모거동(1)

이광진(KwangJin Lee),김균택(KyunTak Kim),김영식(YeongSik Kim) 한국트라이볼로지학회 2011 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.27 No.6

AI/SiC composites were fabricated by thermal spray process, and the dry sliding wear tests were performed using the various sliding speed of 1O, 30, 60 and 90 RPM through 1000 cycles. The applied load was 10 N and radius of wcar track was 15 ㎜. Wear tracks on the Al/SiC composites were investigated using scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy (EDS). In the case of sliding speed of 10 RPM, adhesive wear behavior caused by plastic deformation of composits surface was observed. In the cases of sliding speed of 30, 60, 90 RPM, abrasive wear behavior on the adhered layer formed by debris were observed. Through this study, it was found that the wear behavior of Al/SiC composites was mainly influenced by the sliding speed.

수행평가에서 학습자 특성을 고려한 웹 기반 다차원-개별 적응적 피드백 방법 연구

최현종(Choe Hyunjong),백장현(Baek Janghyeon),김태영(Kim Taeyoung),김영식(Kim Yeongsik) 한국HCI학회 2004 한국HCI학회 학술대회 Vol.2004 No.2