DLC와 PTFE표면코팅에 따른 자기유변유체의 마찰 마모 특성

장붕(Peng Zhang),이광희(Kwang-Hee Lee),이철희(Chul-Hee Lee),최종명(JongMyong Choi) 한국트라이볼로지학회 2015 한국윤활학회지(윤활학회지) Vol.31 No.2

A magnetorheological (MR) fluid is a smart material whose rheological behavior can be controlled by varying the parameters of the applied magnetic field. Because the damping force and shear force of an MR fluid can be controlled using a magnetic field, it is widely employed in many industrial applications, such as in vehicle vibration control, powertrains, high-precision grinding processes, valves, and seals. However, the characteristics of friction caused by iron particles inside the MR fluid need to be understood and improved so that it can be used in practical applications. Surface process technologies such as polytetrafluoroethylene (PTFE) coatings and diamond-like carbon (DLC) coatings are widely used to improve the surface friction properties. This study examines the friction characteristics of an MR fluid with different surface process technologies such as PTFE coatings and DLC coatings, by using a reciprocating friction tester. The coefficients of friction are in the following descending order: MR fluid without any coating, MR fluid with a DLC coating, and MR fluid with a PTFE coating. Scanning electron microscopy is used to observe the worn surfaces before and after the experiment. In addition, energy dispersive X-ray spectroscopy is used to analyze the chemical composition of the worn surface. Through a comparison of the results, the friction characteristics of the MR fluid based on the different coating technologies are analyzed.

중국 대학교 인터넷 안전 및 윤리교육 현황 및 수요조사 연구

장붕 ( Peng Zhang ),이승진 ( Seungjin Lee ) 사단법인 아시아문화학술원 2021 인문사회 21 Vol.12 No.6

본 연구는 중국 대학의 인터넷 안전 및 윤리 교육과정의 방향성을 모색하기 위해 중국 대학생 471명을 대상으로 해당 교육 현황과 수요를 조사를 실시하였다. 분석결과, 90% 이상의 학생들이 인터넷 안전 및 윤리 관련 교육의 필요성을 인식하는 것으로 나타났고 70% 이상의 학생들이 정규 수업개설이 필요하다고 응답했다. 대학생들은 이론보다는 사례와 실습 위주의 수업 방식을 선호하는 것으로 나타났으며, 교육과정 목표는 인터넷 안전의식 강화, 인터넷 범죄 예방, 안전한 인터넷 환경 조성, 인터넷 피해 대응 및 대처 등이 되어야 한다고 응답했다. 마지막으로, 본 연구는 대학생을 대상으로 실시한 인터넷 안전 및 윤리교육 현황과 수요조사로, 학교당국이나 교수를 포함한 연구결과와는 차이가 있을 수 있다. 따라서 향후 연구에서는 이를 포함하여 비교·분석해야 할 것이다. This study conducted a survey on the current status and demand of 471 Chinese university students to explore the direction of the Internet safety and ethics curriculum of Chinese universities. As a result of the analysis, it was found that more than 90% of students recognized the need for Internet safety and ethics-related education, and more than 70% of students responded that it was necessary to open regular classes. It was found that college students prefer the teaching method centered on case studies and practice rather than theory, and they responded that the curriculum goals should be to strengthen Internet safety awareness, prevent Internet crime, create a safe Internet environment, and cope with Internet damage. Lastly, this study is a survey on the current status and demand for Internet safety and ethics education conducted for university students, and may differ from the results of research including school authorities and professors. Therefore, future research should include them and compare and analyze the results.

The Design and Analysis of a Permanent Magnet Reluctance Motor with High Efficiency

장붕(Peng Zhang),권순오(Soon-O Kwon),홍정표(Jung-Pyo Hong) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.7

Based on the requirement of high power and efficiency in automobile systems, this paper describes an investigation for the optimum design of a permanent magnet reluctance motor(PRM), and then the characteristics of this kind of motor is compared with that of a interior permanent magnet(IPM) motor. The IPM of 4-pole with 6-slot is redesigned into a PRM, which has the same stator and different rotor structure with IPM. Through finite element analysis(FEA) and equivalent circuit method, the PRM has higher salient ratio, higher efficiency at high speed, and lower iron loss compared with IPM.

중국 대학교 인터넷 안전 윤리교육 현황 연

장붕 ( Peng Zhang ),이승진 ( Seungjin Lee ) 사단법인 아시아문화학술원 2021 인문사회 21 Vol.12 No.4

중국 대학에서 인터넷 안전 및 윤리교육은 시작 단계로 정규교과 과정으로서의 인터넷 안전 및 윤리 관련 교육 편성에 대한 필요성이 요구되고 있다. 이에 본 연구는 중국 10개 ‘우수 인터넷 안전학과 구축 시범대학’의 교양교육과정 및 비교과 활동 분석을 통해 중국대학들의 인터넷 안전 및 윤리 관련 교육 현황과 발전 방향성을 탐색하였다. 연구결과 10개 대학들은 인터넷 안전 및 윤리교육을 제공하고 있지만 인터넷 안전 및 윤리 교육을 목적으로 개설된 단독 교육과정이 없는 것으로 나타나 빠른 시일 내에 해당교과목의 정규교과 과정이 마련되어야 할 것이다. 본 연구는 해당 대학교 홈페이지에 공개된 자료를 중심으로 분석하여 구체적 비ㆍ교과 수업현황을 확인하는 데는 한계가 있었다. 따라서 향후 연구에서는 해당학교 담당자, 담당 교수 및 수강생을 대상으로 인터넷 안전 인식현황 및 정규 수업개설 필요성에 대한 수요조사를 실시하여 중국대학의 인터넷 안전 및 윤리 교육 교과목 교육과정 확립에 기여해야 할 것이다. In China, ‘Internet Safety Ethics’ education in the university curriculum is in early stage, and the need for ‘Internet Safety Ethics’ related education is required as a regular curriculum. This study explored the direction of education for ‘Internet Safety Ethics’ by analyzing the curriculum in 10 ‘Excellent Internet Safety Department Establishment Demonstration Universities’ in China. It was found that ‘Internet Safety Ethics’ education is provided as irregular education, then the related curriculum should be prepared in the near future. This study analyzed the information published on the university website, and there are limitations in analyzing the specific (non)curricular status. Therefore, the future research will conduct a demand survey on the status of the necessity to open regular classes with cooperating with the school administrator, professors, and students to establish Internet safety and ethics education courses.

재질과 자기장 세기가 자기유변유체의 마찰 특성에 미치는 영향

장붕(Peng Zhang),이광희(Kwang-Hee Lee),이철희(Chul-Hee Lee) 한국트라이볼로지학회 2013 한국윤활학회지(윤활학회지) Vol.29 No.1

Magnetorheological (MR) fluid belongs to the group of smart materials. In MR fluid, iron particles in base oil form chains in the direction of the applied magnetic field, thus resulting in a variation in the stiffness and damping characteristics of the fluid. Research is being carried out on controlling the stiffness and damping characteristics as well as the tribological characteristics of the MR fluid. In this study, the friction characteristics of MR fluid have been evaluated using three types of materials and magnetic fields of different strengths. The coefficients of friction of the three types of MR fluid are measured, and the relationship between the coefficient of friction and the strength of the applied magnetic field is obtained.

왕복 조건에서 3D 프린팅 용 PLA의 마찰 및 마모 특성

홍이(Yi Hong),장붕(Peng Zhang),이광희(Kwang-Hee Lee),이철희(Chul-Hee Lee) 한국트라이볼로지학회 2015 한국트라이볼로지학회 학술대회 Vol.2015 No.10

마그네틱 토크와 릴럭턴스 토크 비율에 따른 IPMSM의 출력 특성에 관한 연구

권순오(Soon-O Kwon),이지영(Ji-Young Lee),방량(Fang Liang),장붕(Peng Zhang),홍정표(Jung-Pyo Hong) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.7

Interior permanent magnet synchronous motor(IPMSM) has higher power density than other PM (permanent Magnet) machines due to reluctance torque in addition to magnetic torque, and the ratio of magnetic and reluctance torque has influences on motor characteristics such as input current, efficiency, power factor, etc. Therefore, this paper presents the output characteristics of IPMSM according to the ratio magnetic and reluctance torque of IPMSM and discuss the design strategy of IPMSM.

Improvement of efficiency in Multi-layer IPMSM using Response Surface Methodology

방량(LIANG FANG),권순오(SOON-O KWON),이상호(SANG-HO LEE),장붕(PENG ZHANG),홍정표(JUNG-PYO HONG) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.7

This paper deals with the optimum rotor design approach about the multi-layer design of the buried magnets in an Interior Permanent Magnet Synchronous Motor (IPMSM), on the efficiency improvement by using Response Surface Methodology (RSM). In the multi-layer design of the prototype 15㎾ IPMSM, the constant amount of buried PM is split from the single-layer into double-layer design for improving the efficiency characteristics. The optimum double-layer rotor structure is built with the help of RSM analysis. The improvement of IPMSM efficiency is verified by the Finite Element Method (FEM) results comparison with the prototype single-layer IPMSM.