Newton 유체의 방사공정에서의 운동학적 파동

김병민,현재천 ( Byung Min Kim,Jae Chun Hyun ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.1

온도 유지시간 제어를 적용한 하이브리드 분말 압출 공정을 통한 요구 특성의 스퍼기어 제조

이경훈(Kyung Hun Lee),황대원(Dae Won Hwang),김병민(Byung Min Kim) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.8

본 연구는 압출 시 성형온도를 유지하여 Zn-22Al 합금분말의 성형성을 향상시키는 하이브리드 분말 압출 공정의 개발 및 온도 유지시간이 압출된 스퍼기어의 기계적 특성에 미치는 영향을 조사하기 위해 수행되었다. 피치원 지름 1.8mm 의 소형 스퍼기어는 압출온도 290, 300, 310℃에서 성형되었다. 볼밀시간 32h 의 Zn-22Al 합금분말을 압출온도 310℃에서 압출 시 표면 결함이 없는 소형 기어가 제조되었다. 경도분포는 기어 중심부와 치형부에서 불균일하였고 소결공정 후 내부 변형에너지의 차이로 인해 내부균열이 발생하였다. 위와 같은 문제를 해결하기 위해 온도 유지시간 제어를 이용한 하이브리드 압출 연구를 수행하였다. 압출된 스퍼기어의 평가는 압출하중, 비커스 경도 및 치수정밀도 측정을 통해 이루어졌다. 온도 유지시간 15min 에서 압출된 스퍼기어의 기계적 성질이 가장 우수하였다. In this study, a hybrid powder-extrusion process involving the control of temperature dwelling time for improving the formability of Zn-22Al powder was developed and the effect of dwelling time on the mechanical properties of a spur gear with a pitch circle having a diameter of 1.8 mm was investigated. General extrusion experiments were carried out at different temperatures such as 290, 300, and 310°C. Spur gears with good qualities and without any surface defects were obtained in the case of extrusion temperature of 310°C and ball-milling duration of 32 h. The Vickers hardness distribution was non-uniform, and after the sintering process, an internal crack was generated because of the different deformation energy between gear central part and teeth. To overcome the abovementioned problems, research on controlling the dwelling time of the extrusion temperature in the powder-extrusion process was carried out. Good-quality spur gears were obtained when the dwelling time was 15 min.

Loop Delay Analysis of All-Digital Phase-Locked Loop using Verilog Behavioral Simulation

Byung-min Kim(김병민),Deog-kyoon Jeong(정덕균) 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.1

팬데믹 상황에서 예체능 전공 대학생의 온라인 수업에 대한 학업 정서가 학습성과에 미치는 영향

김병민 ( Kim¸ Byung Min ) 한국체육학회 2021 한국체육학회지 Vol.60 No.2

본 연구는 코로나19로 인한 팬데믹 상황에서 온라인 수업을 수강한 예체능 전공 대학생의 학업 정서가 인지된 성취도 및 학습만족도에 미치는 영향을 규명하는 데 그 목적이 있다. 본 연구의 결과 도출을 위하여 수집된 자료는 SPSS 24.0과 AMOS 22.0을 이용하여 처리하였고, 빈도분석, 신뢰도분석, 상관관계 분석, 확인적요인분석, 구조방정식 모형 검증을 실시하였다. 연구 결과는 첫째, 즐거움, 자부심, 지루함 정서와 인지된 성취도에서 유의한 영향 관계를 나타냈다. 둘째, 즐거움과 화 정서는 학습만족도에 유의한 영향을 미치는 것으로 나타났다. 셋째, 인지된 성취도는 학습만족도에 유의한 영향을 미치는 것으로 나타났고, 인지된 성취도는 자부심과 학습만족도와의 관계에서 완전매개효과가 나타났다. 이러한 결과에 따라 학업 정서는 학습성과에 영향을 미치는 주요 변수임을 확인하였고, 학습자의 성취도와 만족도를 높이기 위하여 학생들의 정서를 고려한 체계적이고 전략적인 학습설계 및 교수법 등이 필요하다. 또한 포스트 코로나 이후에도 학생들의 학습성과를 향상하기 위한 다양한 전략이 요구된다. The propose of this study was to investigate the effects learning emotions of college students majoring in arts and sports who took online classes a pandemic situation caused by of COVID-19 on perceived achievement and learning satisfaction. To derive the results of this study, data were processed using SPSS 24.0 and AMOS 22.0, and frequency analysis, reliability analysis, correlation analysis, confirmatory factor analysis, and structural equation model equation model verification were performed. The results of the study were as follows: First, enjoyment, pride, and boredom had a significant effect on perceived achievement. Second, enjoyment and anger had a significant influence on learning satisfaction. Third, perceived achievement effect on learning satisfaction, the perceived achievement showed a complete mediating effect in the relationship between pride and learning satisfaction. Based on these results, it was confirmed learning emotion is a major variable influencing learning outcomes, in order to increase learner achievement and satisfaction, systematic and strategic learning methods that consider students’ emotions are needed. In addition, various strategies are required to improve student learning outcomes even after the post-corona.

나노 인덴테이션 시험에서의 탄소성 재료의 파일업/싱크인 특성

김병민(Kim Byung Min),이찬주(Lee Chan Joo),이정민(Lee Jung Min),이상진 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Over the past decade, many computational researches have been performed to investigate quantitative relationships between load-displacement and material properties. But piling-up which causes errors to estimate mechanical material properties remains the most significant unresolved issue in nano-indentation test. This study has estimated quantitative aspects of the effects of material properties, especially work hardening exponent, on piling up/sinking in response of various materials. Using FE Analysis, piling up/sinking in response when material is indented by sharp indenter is investigated to evaluate the effects of material properties. From the FE analysis result, quantitative relationships between piling up/sinking in height and material properties is assessed using dimensional analysis which is used to define scaling variables and universal functions. And nano-indentaion test is performed to verify this relation on various materials. From the result of comparison with prediction from dimensional function and experiment, the work hardening exponent was found to have greater influence on the piling up/sinking in height during the nano-indentation than other material properties, such as elastic modulus and yield stress.

NCAR 재해석 자료를 이용한 극한풍속 예측

김병민(Kim, Byung-Min),김현기(Kim, Hyun-Gi),권순열(Kwon, Soon-Yeol),유능수(Yoo, Neung-Soo),백인수(Paek, In-Su) 강원대학교 산업기술연구소 2015 産業技術硏究 Vol.35 No.1

Two extreme wind speed prediction models, the EWM(Extreme wind speed model) in IEC61400-1 and the Gumbel method were compared in this study. The two models were used to predict extreme wind speeds of six different sites in Korea and the results were compared with long term wind data. The NCAR reanalysis data were used for inputs to two models. Various periods of input wind data were tried from 1 year to 50 years and the results were compared with the 50 year maximum wind speed of NCAR wind data. It was found that the EWM model underpredicted the extreme wind speed more than 5 % for two sites. Predictions from Gumbel method overpredicted the extreme wind speed or underpredicted it less than 5 % for all cases when the period of the input data is longer than 10 years. The period of the input wind data less than 3 years resulted in large prediction errors for Gumbel method. Predictions from the EWM model were not, however, much affected by the period of the input wind data.

단조 금형의 윤활, 표면처리 및 금형 수명 평가

김병민(Byung Min Kim) 한국소성·가공학회 2002 소성가공 : 한국소성가공학회지 Vol.11 No.3

입시 체육학원의 선택속성, 교육서비스 품질, 추천 의도의 관계 : 성별의 조절효과

김병민(Kim, Byung-Min) 한국체육과학회 2021 한국체육과학회지 Vol.30 No.3

The purpose of this study was to investigate the relationship between the selection attributes of physical education academies, educational service quality, and recommendation intention of physical education college candidates, and to identify the role of gender as a modulating variable in this relationship. To achieve this purpose, frequency analysis, reliability analysis, correlation analysis, structural equation model verification, and moderating effect analysis were performed using SPSS and AMOS programs, and the following results were found. First, among the selection attributes, leader, external environment, accessibility, counseling, and cost were found to have a significant influence on all sub-factors of education service quality. Second, it was found that among the education service quality, instructor・staff quality and operation quality had a significant effect on recommendation intention. Third, it was found that gender has a moderating effect on the influence of internal environment, external environment, accessibility, cost, and relationship factors on the quality of education service. In addition, there was a moderating effect in the relationship between instructor・staff quality and recommendation intention. Based on these results, it was necessary to conduct continuous research on physical education college candidates and marketing strategies according to gender, consumption tendency, and individual characteristics.

축 대칭 전방 압출의 극한 해석

김병민(Byung Min Kim),최인근(In Keun Choi),최재찬(Jae Chan Choi),이종수(Jong Soo Lee) Korean Society for Precision Engineering 1991 한국정밀공학회지 Vol.8 No.3

온라인강의에서의 수업의 질, 자기효능감, 학습자 충성도의 관계 및 전공과 아르바이트 활동에 따른 차이 분석

김병민(Kim, Byung-Min),강유원(Kang, Yu-Won) 한국체육과학회 2021 한국체육과학회지 Vol.30 No.2

The purpose of this study was to identify the relationship between the quality of classes, self-efficacy, and learner loyalty of college students who took online university lectures, and to determine whether there was a difference in the level of perception of variables according to their major and part-time job activities. For the data processing of this study, frequency analysis, reliability analysis, one-way ANOVA, simple regression analysis, and multiple regression analysis models were performed using SPSS 24.0. As a result, first, the class content and the classroom environment had a positive effect on the sense of self-efficacy, and the interaction showed a negative influence on the sense of self-efficacy. Second, it was found that the classroom environment and interaction had a positive effect on learner loyalty. Third, it was found that self-efficacy had a positive effect on learner loyalty. Fourth, students of physical education major showed high class content, class environment, and learner loyalty. Finally, the group who did not engage in part-time job activities sometimes showed higher class quality and learner loyalty than one group. In accordance with these contents, it is necessary to prepare a plan for improving the quality of classes, such as collecting various demands of students and providing a learning design and an appropriate environment suitable for the provision of high-quality educational services for online classes at universities.