기어의 백래쉬를 고려한 승용차 조향계의 동특성 연구

김종관,김경석,송상기,정진형 한국공작기계학회 1996 한국생산제조학회지 Vol.5 No.3

The problem related to the rotational vibration at steering wheel end of passenger cars during high speed driving is investigated. To analyze vibration of steering wheel, a steering system of passenger car is modelled in twelve degrees of freedom including backlash effect of rack and pinion gear system. The one degree of freedom system with backlash in investigated by the analytical method . Consequently the skeleton curve and the frequency response curves are computed. The steering system is analyzed by the numerical simulation using the 4th order Runge-Kutta method, the obtained results are compared with the experimental data. Also the effects of the change of rack gear tooth stiffness and backlash on the acceleration level of steering wheel are investigated. As a result, it can be found that the acceleration level of steering wheel becames lower as the rack gear tooth stiffness becames higer, and that acceleration level becames high as the magnitude of backlash between rack and pinion gear increase.

해면 정맥동 혈전증(Cavernous Sinus Thrombosis) 치험례

김경원,김용관,장명진,장현석 大韓顎顔面成形再建外科學會 1995 Maxillofacial Plastic Reconstructive Surgery Vol.17 No.4

Cavernous sinus thrombosis is one of the major complications of abscesses of the maxillofacial region. The initial symptoms of CST are usually pain in the eye and tenderness to pressure. this is associated with high fluctuating fever, chills, rapid pulse, and sweating. Venous obstruction subsequently causes edema of the eyelids, lacrimation, proptosis, chemosis and retinal hemorrhages. Blindness is sometimes an accompaniment of cavernous sinus thrombosis when the infection also involves the orbit. There is also cranial nerve involvement (oculomotor, troclear, abducence) and ophthalmoplegia, diminished or absent corneal reflex, ptosis, and dilation of the pupil occur. The terminal stages bring signs of advanced toxemia and meningitis. Infections of the face can cause a septic thrombosis of the cavernous sinus. Furunculosis and infected hair follicles in the nose are frequent causes. Extractions of maxillary anterior teeth in the presence of acute infection and especially curettage of the sockets under such circumstances can cause this condition. The infection is usually staphylococcal. The inflection may spread directly through the pterygoid plexus of veins and the pterygomaxillary space and then ascend into the sinus or it may spread directly from the pterygopalatine space to the orbit. This is possible because of the absence of valves in the angular, facial, and ophthalmic veins. The treatment is empirical antibiotic therapy followed by specific anbibiotic therapy based on blood or pus culture. The inflection usually involves one side, however, it may easily spread to the opposite side through the circulus sinus. Unless it is treated early, the prognosis is poor even in this doses. Occasionally the antibiotics will not adequately resolve the septic thrombus, and death ensues. the use of anticogulants to prevent venous thrombosis has been recommended, but the efficacy of such therapy has not been substantiated. Surgical access through eye enucleation has been suggested. We report a case which demonstrates cavernous sinus thrombosis by the infection after the functional neck dissection and the intraoral reconstruction with auriculomastoid fascio-cutaneous island flap.

IEEE1394 제어기술을 이용한 정보 가전기기 컨텐츠

백경주,강성관,이상학,이승학,박종안 조선대학교 전자정보통신연구소 2002 電子情報通信硏究所論文誌 Vol.5 No.2

Internet appliances information industry is the future industry fields of Existing as a appliance market becomes saturation. Such as digital TV, Internet refrigerator, DVD and digital video that next generation digital goods appear the importance of the information appliances have been emphasized. in this paper, recently wire & wireless home networking technology for Internet appliances combine and connects, data send a broadband with 400Mbps & 3.2Gbps than used IEEE1394 information technology such as design implemented the system to control besides and proved the adequacy through the simulation.

경계층 난류박리의 제어에 관한 연구 : 제1보;매끄러운 2차원 디퓨저 벽면에서의 난류박리특성 First Report;Turbulent Separation Characteristic on the Smooth 2-Dimensional Diffuser Wall Surface

신정관,박종일,이한영,김경훈 경희대학교 산학협력기술연구원 1995 산학협력기술연구논문집 Vol.1 No.-

The structure of the turbulent wall layer developing into flow separation was studied. The experiments were performed to find out the formation of turbulent separation lead to diverging of the diffuser wall in a two-dimensional asymmetric diffuser which was attached to a downstream end of a long straight channel to provide a fully-developed turbulent inlet condition. First report, this is to estimate how to develop the region of the separation in the smooth diffuser wall with diverging condition and then is the reference on the characteristics of rough diffuser wall being under discussion at second report. As a result, static pressure profile of the fixed wall are in accord with the static pressure profire of the movable wall. Separation has broken out at the diffuser open angle θ=7o, while the diffuser openingangle is increasing, the region of the separation is advanced at the upstream and separation appears at the diffuser open angle θ=12o in the fixed wall too.

교원평가제에 관한 연구 : 누구와 무엇을 위한 평가인가

최관경 부산대학교 초등교육연구소 2005 초등교육연구 Vol.20 No.-

The purpose of this study is not only to find the function and dysfunction of teacher evaluation but also to dicern the main dispute points over a new teachers' evaluation system between the Education Ministry and the nation's major teachers' groups(KTFA and KTU). The teacher is the indispensable element in the school. Teacher expertise is the single most important determinant of student achievement. To improve student achievement and to enhance the quality of schooling, we must improve teacher performance and quality. In fact, teaching is a very complex activity and is not reducible to a set of teaching behaviors. Why do we evaluate teachers? There are three main reasons to evaluate teachers: 1. To improve teacher effectiveness 2. To encourage professional growth 3. To remediate or eliminate weak teachers Two reasons stated above deal with the development of teachers ; one relates to making a judgment about the competence of a teacher for reasons of future assistance or employment. One problem with teacher evaluation is that it has used for two purposes:(a)helping the teacher improve(formative evaluation) and at the same time (b)determining the future employment status of the teacher(summative evaluation). Especially, teacher evaluation should include teacher self-evaluation, peer observations, and peer coaching. Teachers must be freed from the fear of negative evaluation if they are going to engage willingly in a process to improve the quality of their professional work. According to Mc Greal, no single idea or concept has been more detrimental to successful teacher evaluation than the rating scale (Beerens, 2000:11). The de-emphasis of grading, rating, and ranking is fundamental to the success of new teacher evaluation system. The current evaluation system was criticized for not adequately measuring teachers' performance because only a principal, who rarely attends classes, assesses school staff. Forty-eight elementary, middle and high schools across the country were selected by The Education Ministry will operate the new system until next August on a trial basis. Under the ministry's plan, students would fill out a survey measuring how satisfied they are with their teachers, and parents would also evaluate their children's satisfaction level with school. Teachers would also evaluate other teachers' work on class preparation materials and curricula. However, the nation's two major teacher's groups, KTU(Korean Teachers and Education Workers' Unions) and KTFA(Korean Teachers Federation Association) have vehemently opposed the plan to broaden the evaluation, saying the government should invest more in schools instead. Teachers are in doubt about the government's plan and say that the new system won't reflect their promotion or wage and will be solely for "self-development."

성과 에이즈에 관한 보건교육 방법별 효과 측정

권관우,이경무,김훈수,김정순,정경균 韓國保健敎育.健康增進學會 2000 보건교육건강증진학회지 Vol.17 No.2

The objective of this study is to find the most effective educational method on Sex and AIDS/HIV among young people in Korea. The number of people with HIV amounts to 1,224 as of Sep. 2000, and is increasing continuously, especially among young people(National Institute of Health, 2000). In setting up the policy of health education on Sex and AIDS, the criteria should be the effectiveness. By two-stage cluster sampling, 4,713 students were selected from among the 19,093 students from 44 middle and high schools and divided into three groups and taken the education with three different methods(〈lecture with slides show〉, 〈lecture without any material〉 and 〈lecture through broadcasting system〉) by the same lecturer with the same contents for about 50 minutes. To compare the effects of education by methods, the tests on the AIDS knowledge, AIDS attitude on AIDS and Sexuality attitudes with self-administered questionnaire were implemented three times, that is, 'before', 'right after' and '2 weeks later' of the education. As to the decrees of change of AIDS knowledge, AIDS attitudes, Sexuality attitudes and subjective evaluation of the education, 〈lecture with slides show〉 was the most effective, 〈lecture without any material〉 was the second and 〈lecture through broadcasting system〉 was the least effective, respectively. In the cost-effectiveness analysis using the results of this study, 〈lecture with slides show〉 turned out to be the most effective, and 〈lecture through broadcasting system〉 was the second and 〈lecture without any material〉 was least effective. From these results, it is suggested that 〈lecture with slides show〉 is more effective health educational methods on Sex and AIDS than 〈lecture without any material〉 or 〈lecture through broadcasting system〉.

Shield Disk 상의 Ag-Cu 공정계 합금 도금기술 개발

윤경도,차동관,심기종,민봉기,최순돈,이상기 嶺南大學校 工業技術硏究所 2003 工業技術硏究所論文集 Vol.31 No.1

The composition and the microstructure of the Ag-Cu alloy electrodeposits electroplated in Succinimide bath were investigated varying the electrolysis conditions such as bath composition, current density and additive agents etc. The cathode overpotential increased with the increase of Succinimide concentration and current density ratio in the bath. The Ag content of the alloy deposits decreased with the increase of current density and pH and temperature in the bath. The optimum condition for 78wt.%Ag-22wt.%Cu code position alloy is an follows : pH10(adjusted by NH_4OH), 0.03M AgNO_3, 0.27M Cu(NO_3)_2 3H_2O, 0.5M Succinimide in bath and 3.5A/dm^2∼5.5A/dm^2 current density.

중고등학생의 에이즈 豫防敎育을 통한 에이즈 知識과 性意識 變化에 關한 硏究

권관우,이경무,김정순 韓國學校保健學會 1999 韓國學校保健學會誌 Vol.12 No.1

AIDS is worldwide problem. It has threatens societies and is potentially a big problem among youth. UNAIDS has warned that collective global responses are necessary; with half of the newly infected being children and young people in 1998, educating youth below age 24 is essential. Because of both their unexpected, strong sexual activities and an easjer tendency to change their behavior than adults, UNAIDS emphasizes the importance of prevention education leer youth. In Korea, 4 cases of HIV infection have officially been reported among high school students. Considering the potential seriousness of HIV inflection among youth, the Korean Anti- AIDS Federation (KAAF) began an education programme for Korean youth (middle & high school pupils) as one intervention method in 1993. The purpose of this study is to evaluate the impact of the education programs performed and to develop a better programme. The intervention method used in this study was mainly a lecture in a big or small auditorium or through broadcasting systems using audio-visual teaching aids. The period of this survey was from Nov. 10 to Dec. 26. in 1998. The subjects surveyed were 792 pupils who were sampled from 12 different middle and high schools in Seoul by a two-stage cluster sampling. Self recording the structured questionnaire was used far data collection. Data were analyzed by using a paired t-test to compare the knowledge difference before and after the interrention method. A chi-square test to compare the consciousness difference between pre-post-education results was used, and an ANOVA was used to compare the knowledge difference among the selected groups. Major results of this study are summarized as follows: (1) AIDS knowledge significantly changed after AIDS prevention education. (2) The direct lecture in a big or small auditorium is more effective than an indirect lecture through a broadcasting system or through audio-visual teaching aids. (3) Those who had not seen obscene materials (e.g. pornography films, magazines etc.) acquired much more knowledge than others after AIDS prevention education. (4) Those who had no girlfriend/or boyfriend acquired much more knowledge than the others after AIDS prevention education. (5) As to the attitudes toward chastity, more girls than boys and students who had not seen obscene materials rather than those who already had were liable to support the state ment: "all should remain chase" and their consciousness on "being chaste" changed much more than that of others after intervention. (6) As to the individual evaluation of lectures, 23.1% shows "very good" , 44.1% "good" , 26.9% "normal"'-'thus, the positive evaluation was to 94.2%. The negative response was 5.8%. (7) As to the desire fur AIDS education sponsored by KAAF in the future, more than몫90.5% showed a positive reaction. (8) As to the educators in future education methods, pupils wanted lecturers from outside their schood. (9) Students from vocational high schools have seen obscene materials much more than other groups and the percentage of these who had a girlfriend/or boyfriend was higher than that of the ethers as wello. (10) 90% of those who watched obscene materials responded that they experienced these materials while at middle school and 100% before reaching the second grade of high school. (11) The number of boys who have experienced obscene materials is twice as many as that of girls. (12) The percentage of boys who have a girlfriend is much higher than the percentage of girls who have a boyfriend. (13) Among those who have friends of the opposite sex, 11.1% say that they hare had sexual contact and 20.8% hare experienced kissing and caressing.

활성탄/플리우레탄 복합담체를 충전한 바이오필터에서 H₂S의 제거특성

감상규,강경호,임진관,이민규 한국환경과학회 2004 한국환경과학회지 Vol.13 No.1

A biofiltration system using activated carbon/polyurethane composite as solid support inoculated with Bacillus sp. was developed for treating a gaseous stream containing high concentrations of H₂S. The effects of operating condition such as the influent H₂S concentration and the empty bed contact time (EBCT) on the removal efficiency of H₂S were investigated. The biofilter showed the stable removal efficiencies of over 99 % under the EBCT range from 15 to 60 sec at the 300 ppmv of H₂S inlet concentration. When the inlet concentration of H₂S was increased, the removal efficiencies decreased, reaching 95 and 74%, at EBCTs of 10 and 7.5 sec, respectively. The maximum elimination capacity in the biofilter packed with activated carbon/polyurethane composite media was 157 g/m³/hr.

하수에서 분리한 합성세제 분해균의 특성

정민선,전진경,정영건,이해경,권오진,지원대,김관배 嶺南大學校 環境問題硏究所 1993 環境硏究 Vol.13 No.1

대구시와 경산시의 하수에서 음이온계 합성세제인 sodium dodecyl sulfate(SDS)와 sodium dodecylbenzene sulfonate(SDBS)를 유일한 탄소원으로 이용하는 균주 289종을 분리하고 이중 합성세제 분해력이 강한, 그람음성 간균으로 운동성인 8균주를 선정하여 그 선정균들의 특성을 조사하였다. 선정균은 40℃ 이상에서는 생육하지 못하였으며 생육 최적 pH는 균주간에 다소 차이가 있었으며 pH 4.0 이하에서는 선정균 모두 생육치 못하였다. 질소원으로는 SDS분해균의 생육에는 potassium nitrate가, SDBS 분해균의 생육에는 soytone이 좋았다. SDS 분해균인 DS-3, 6, 8, 24 및 SDBS 분해균인 BS-7, 8은 세제농도가 5.0% 이상에서도 생육이 가능하였다. 선정균들은 tetracycline에 감수성이 강한 것으로 나타났지만 penicillin에는 강한 내성을 띠는 것으로 나타났고, ??와 ??금속이온은 모든 선정균들의 생육을 억제하는 것으로 나타났다. On purpose to isolate the organisms, which would utilize detergents(sodium dodecyl sulfate, SDS and sodium dodecylbenzene sulfonate, SDBS) as a sole carbon source, from the waste water of Kyungsan and Taegu city 289 strains were isolated. Among them 8 strains, which are gram negative rods with motility and produce strong enzyme to biodegrade the synthetic detergents, were selected. The characteristics of them were investigated as follows, 8 strains were failed to grow above the temperature of 40℃ and below the pH 4.0 even though they have variable optimum pH. Potassium nitrate was very effective for the growth of SDS-biodegradable strains and soytone was effective for the growth of SDBS-biodegradable strains as a sole nitrogen source. Among 8 strains especially DS-3, DS-6, DS-8 and DS-24(SDS-biodegradation strains) and BS-7 and BS-8(SDBS-biodegradation strains) could grow above 5.0% of detergent concentration. All of 8 strains were very sensitive to tetracycline but resistant to penicillin. Selected 8 strains were inhibited by metal ions of ??(0.156mg/㎖) and ??(0.156mg/㎖).