마이크로 프레스 구동을 위한 기어시스템 개발

홍용,김현식,고유곤,홍동표,김성욱 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

In this paper, gear system for Micro-press actuator parts is developed. The micro-press system consists of AC geared servo motor, gear system and high precision ball screw. Herein, the micro-press gear system not only forms the micro thin foil valve but also forms the hydro dynamic bearing for a high precision rotational equipment, we analyzed the transmitted power capacity of gear system and torque, angular velocity of ball screw, because we are to select the appropriate servo motor and then we apply result of analysis to the micro press system. For the next step, we plan to study for the development of forming speed for a productivity with high precision.

나노 세리아 슬러리를 이용한 Stainless steel 304의 MR Polishing 특성에 관한 연구

홍광표,신봉철,김동준,조명우,신영재 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

An finishing process using magnetorheological fluid has been developed as a new precision finishing technique to obtain a fine metal surface. Therefore, magnetorheological fluids has been used for micro polishing and micro part. The applied material is 304 stainless steel. It is widely used in the semiconductor machinery and aerospace industries because of high corrosion resistance. For MR polishing process, MR fluids was consisted of carbonyl iron, DI-water and nano slurry ceria(Celexis cx 94s slurry). The wheel speed and electric current were chosen as the variables for analyzing the characteristics of MR polishing process. In the results, the surface roughness according to the variation of wheel speed was analyzed , and it was obtained 1.393nm surface roughness.

마이크로 프레스 구동을 위한 기어시스템 개발

홍용,김현식,고유곤,홍동표,김성욱 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

In this paper, gear system for Micro-press actuator parts is developed. The micro-press system consists of AC geared servo motor, gear system and high precision ball screw. Herein, the micro-press gear system not only forms the micro thin foil valve but also forms the hydro dynamic bearing for a high precision rotational equipment. we analyzed the transmitted power capacity of gear system and torque, angular velocity of ball screw, because we are to select the appropriate servo motor and then we apply result of analysis to the micro press system. For the next step, we plan to study for the development of forming speed for a productivity with high precision.

탄소섬유 프리프레그 외부 표면 적층방법에 따른 하이브리드 샤프트 진동특성

홍동표,김현식,홍용,고유곤,유청환 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

Studies on carbon fiber epoxy composite is being conducted broadly in industries because of its specific stiffness, specific strength and good fatigue resistance. Because carbon fiber epoxy composite has high vibration characteristics, if existing metal material is alternated by carbon fiber epoxy composite, structure will be low weight, satisfy 1st bending natural frequency and have high fatigue resistance. In this study, research on to manufacture hybrid propeller-shaft using carbon fiber epoxy composite instead of current steel propeller shaft of rear wheel drive vehicle. For this, change of 1st bending natural frequency by the number of layers of carbon fiber epoxy composite on the outer surface of aluminum shaft was observed. Compared the change of 1st bending natural frequency by FEA with computer simulation and vibration test. Through this, the amount of increase in 1st bending natural frequency of hybrid shaft by the increase in number of layers of carbon fiber epoxy composite and high vibration characteristics of hybrid shaft was acknowledged.

지역사회 정신의학 전공의 교육과정 실태조사

홍진표,황순찬,이영문,이선형,신나리,이종일,박종익,장동원,정인원 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.1

Objectives : There is a increasing need to recruit and retain more psychiatrists who can plan and implement organized programs to work with chronic mentally ill patients in community settings. The aim of study is to discover what training is currently in place to prepare psychiatrist for work in "community" or "public" settings. Methods : Survey questionnaires were mailed to 85 residency training directors and 10 leaders of community mental health in 2005. Response rate was 75%. Results : Academic seminar about community mental health were not administered to residents in 63% of training hospitals. Forty one out of 64 training hospitals had community mental health rotation programs, Community mental health center (50%) and day hospital (36%) were the most common type of programs. Few general hospital had affiliation with community mental health programs. The amount of time for clinical rotation varied from less than three months part time to 6 months fulltime, with most frequent form of one day per week for three month in second or third year of psychiatry residents. Conclusion : Further steps are needed to improve residency training curricula and to encourage well qualified psychiatrist to choose careers in community psychiatry.

빔 구조물의 손상평가를 위한 임피던스 기술의 응용

홍동표,홍용,왕고평,김병진,김영문,이재정,김재열 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

This paper presents a primary study for a new method of enhancing measurement using impedance analysis method, which is widely used for structure health monitoring. Many of skyscrapers, bridges, tunnels, which have been built up several years, and nearly reached their operating life due to aging crack, material deterioration, and so on. therefore, the health monitoring technique has obtained considerable attention. The goal of this research is to show basic information to evaluate structural health condition using piezoelectric sensors. The piezoelectric materials have various merits. It is easy to shape various forms and can be embedded on the materials more conveniently. Moreover, the excitation frequency can be changed and the piezoelectric sensors cost less. All these features make the piezoelectric-based system applicable to structural healthy monitoring. This work presents a study for the development of a practical and quantitative technique for assessment of the structural health condition by piezoelectric impedance-based technique associated with longitudinal wave propagation. To estimate the damage condition numerically, we suggest the evaluation method Cov (Covariance) and CC (Correlation Coefficient) in this paper.

사행성게임장의 문제점과 ‘관련법규’ 개정방향

홍동표 숭실대학교 법학연구소 2007 法學論叢 Vol.17 No.-

2006년도에 한국 사회를 가장 떠들썩하게 했던 사건은 "바다이야기"로 대표되는 사행성게임장 파문이었을 것이다. 분명하게 말할 수 있는 것은 도박공화국으로 변모된 배경에는 DJ정부에서부터 시작된 잘못된 정책추진결과 였다. 영상물 등급 위원회의 비전문성, 허가제에서 게임산업을 진흥시킨다는 미명하에 등록제로 전환한 정책적 오류, 상품권의 오락실 경품허용 등 수 없는 오류를 범했다. 검찰과 경찰의 수사와 업계의 동향을 살펴보고 관련법규의 문제점에 대하여도 살펴보고 개정방향을 제시하였다. 사행성 게임을 결정하는 기준에 "스크린 경마"가 포함되어야 하고 온라인 도박 싸이트들이 사이버 머니를 전문적으로 교환해주는 싸이트를 통하여 환전하고 있는 것을 막아야 한다. 또한 바다이야기처럼 부가게임으로 빠찡고, 빠찌슬롯, 철게임 등이 부착되는 게임기를 규제하여야 한다. 게임물등급 위원회 위원구성에 "게임산업과 관련된 사람"으로 한정하였는데 게임산업에 관련이 있는 사람들로 구성 되면 사행성을 예방하거나 근절시키는데는 한계가 있을 것이다. 따라서 이러한 불합리한 규정을 개정시켜야한다. The most turbulent issue in Korean society of 2006 is the Game room for Speculation represented by "Bath tales". Frankly speaking, there is a drive of wrong policy from DJ government at the background changed gamble republic. They commited a lot of mistake like non-specialized visual rank committee, policy mistake changed from approval system to registraion system under the cloak of promoting game industry and allowance of use of gift certificate at the game room. This revision direction is proposed referencing the investigation of prosecution and police and relevant law and regulation. The screen horse racing should be included in speculation game, and exchange of cyber money by on-line gamble site througn wep site should be prohibited. the game equipment with Pachingko, Slot machine and Iron game like "Bath tales" should be also restricted. The person only related to game industry can became a member of game rank committee, but if the very persons make the committee, there will be a limitation to prevent the speculation. Therefore, these unreasonable regulation should be revised.

한국 상장기업의 IT자본과 노동 및 비IT자본의 대체성에 관한 연구

문성배,홍동표 한국은행 2004 經濟分析 Vol.10 No.2

본 연구는 2000-2002년까지의 한국 164개 상장기업에 대한 자료를 이용하여 IT자본과 노동 및 비IT자본간의 대체탄력성(elasticity of substitution)을 측정하였다. 특히 생산요소간 대체성의 척도로서 널리 쓰이고 있는 Allen 대체탄력성(Allen elasticity of substitution)의 문제점을 지적하고 Allen 대체탄력성 뿐만 아니라, 가격탄력성, Morishima 대체탄력성(Morishima elasticity of substitution), 그리고 shadow 대체탄력성(shadow elasticity of substitution)을 측정하였다. 본 연구의 추정결과에 따르면, 첫째, IT자본은 노동과 비IT자본에 대한 대체재(substitute)인 것으로 나타났으며, 우리나라 기업들의 경우 IT자본이 노동을 대체하는 정도보다 IT자본이 비IT자본을 대체하는 정도가 큰 것으로 나타났다. 또한 비제조업보다는 제조업에서, 정보화가 덜 된 기업들보다는 정보화가 많이 된 기업들에서 IT자본의 노동과 비IT자본에 대한 대체성이 강한 것으로 나타났다. This paper examines the substitutability of IT capital for other inputs, such as labor and non-IT capital, using the data on 164 Korean firms from the period of 2000-2002. Estimating various elasticities of substitution between IT capital and other inputs, we find that IT capital is a substitute for labor and non-IT capital. In particular, we find that IT capital is more substitutable for non-IT capital than for labor. We also find that the estimated elasticities of substitution between IT capital and other inputs are higher for manufacturing firms than for non-manufacturing firms, and higher for IT-intensive firms than for less-IT-intensive firms.

데스크탑 마이크로 성형시스템의 가진성형에 따른 동특성 연구

홍동표,고유곤,홍용,김현식,이재완 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

In this study, a desktop forming system which enables hydro dynamic bearing forming was developed. It consists of power train system, frequency forming system, manufactured Die-set, and controller of desktop forming system. The desktop micro forming system is focused on a higher load capacity and a shorter forming time than conventional system. Therefore it was designed for power train capability and load condition of Ball Screw. Moreover, a Piezo actuator was installed to make accurate machining possible, however, the Piezo actuator generate noise and vibration. Thus we performed the analysis of dynamic characteristics through the experiment about developed system in order to reduce such problems and discuss the alternative methods.

基礎部에 外亂이 作用하는 ONE-LINK 彈性 ARM의 變位制御에 關한 硏究

홍동표,尹英進,長南征二,猪岡光 全北大學校 1991 論文集 Vol.33 No.-

This paper presents a study on the displacement control of the one-link flexible arm whose tip keeps a constant distance to the fluctuating surface of the target under fluctuation throuhg theoretical analysis and computer simulation. The analytical model is composed of three parts of DC SERVOMOTOR, FLEXIBLE ARM with a length(L), TIP MASS, and acted on the moment and shear force on each part of flexible arm. The relative displacement between the arm and the target is controled by DC servomotor driven by a feedback signal composed of the tip displacement and velocity. In the numerical analysis, Laplace Transform is used for development of the governing equations, and its solution is obtained by applying the method of Numerical Laplace Inversion used the Weeks Method. On this paper, the analysis about transient response of the flexible arm subjected to the square sine wave input signal and unit step input signal was performed through the theoretical analysis and computer simulation.