공간벡터 개념을 이용한 유도 전동기 기동 토크 맥동의 저감에 관한 연구

전희종,정을기,이석태,최우진 崇實大學校 生産技術硏究所 1994 論文集 Vol.24 No.-

In this investigation the PFM(Pulse Frequency Modulation) will be used for optimizing PWM inverter pulse patterns. In traditional the pulse frequency of PWM is kept constant. But modulated PWM's frequency in this study, the sinusoidal inverter's performance should be improved. The PWM pulse patterns are definitely controlled so that the time-integral function of the voltage vectors in the space vector notation may show a circular locus. Further, performance index will be minimized because of minimizing distortion of output current. Finally, these theories are realized using single-chip microprocessor.

마이크로 엔드밀링에서 음향방출 신호를 이용한 상태감시

정연식,강익수,김전하,강명창,김정석,안중환 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

Ultraprecision machining and MEMS technology have been taken more and more important position in machining of microparts. Micro endmilling is one of the prominent technology that has wide spectrum of application field ranging from macro parts to micro products. Also, the method of micro-grooving using micro endmilling is used widely owing to many merit, but has problems of precision and quality of products due to tool wear and tool fracture. This investigation deals with state monitoring using acoustic emission(AE) signal in the micro-grooving. Characteristic evaluation of AE raw signal, AE hit and frequency analysis for state monitoring is also presented in the paper.

시장세분화를 위한 골프갤러리의 라이프스타일에 관한 연구

전익기,이정학,이재돈,신석영 경희대학교 체육대학 한국체육과학연구소 2004 體育學論文集 Vol.32 No.-

The analysis result on the life style of gallery for golf games shown in the study indicates that the majority of people watches the golf related TV programs for 2 hours a week with most favorable ones in women's golf competitions. The number of people watching the golf competitions is 3 times a year with the preference on women's competition rather than men's competition Approximately 34∼36% of the golf galleries has health club or golf course membership, with 45% subscribed to a golf magazine and most of them possessed the gold credit cards. They made investment mainly through real estate and had interest in well being, particularly in well being food. In addition, 83% of the golf gallery had experienced in overseas travel in the past two years, and 55% of the galley had taken overseas golf tour. Furthermore, the vehicles golf fans had were in the order of Grandeur, Equus, and BMW and the main use of the vehicles were for work, and in the recognition of brand for imported cars was shown in the sequence of BMW, Benz, Lexus and others. However, such a life style and attitude of sports consumers is not a firm one in any means. The life style of the sports consumers change along with the flow of time that the continuous research on the life style of golf consumers, such as this study, has to be made, and when the accumulation of such data would be a precondition for establishing the effective marketing strategy.

만성 강박장애 환자의 정서처리 특성 : 정신분열병 환자 및 정상인과의 비교

석정호,김재진,전종희,이홍식,안석균,이은,김찬형 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.3

Objectives : Obsessive compulsive disorder (OCD) tends to take chronic course as schizophrenia. Researchers reported that OC patients had idiosyncratic sensitivity to threat-related information, while schizophrenic patients were reported to have affec-tive blunting. We hypothesized that there might be a difference in emotional response between OCD and SPR in cronic phase. Methods : Eight different emotional tasks were done by 25 healthy controls, 21 OCD patients and 25 SPR patients. Visual stimuli were made by pairing two words or pictures. Four kinds of emotional stimuli (positive, negative, combined and neutral)were presented to subjects through monitor and they were asked to report their subjective feelings by pushing mouse button, In the combined condition, a pair of positive words (or pictures) and negative words (or pictures) were presented simultaneously. The responses and response time were recorded and analyzed using SPSS 9.0 package. Results : In the negative condition, OCD group didn't show any deficit compared to healthy group. But SPR group showed significantly lower appropriate response rate than healthy group, In the combined condition, OCD and healthy control group Showed 'negativity bias' which SPR group didn't show. In the positive condition, however, OCD and SPR groups did show Significantly lower appropriate response rate than healthy controls. Conclusion : Our results suggested that OCD patients may not have deficits in the processing of negative emotion even in the chronic phase but to have a specific deficit in positive emotion. This result supports the 'threat-relatedness hypothesis' on attentional bias of OCD.

갑상선기능저하증에 기인한 내인성 급사 1예 보고

이정규,전지현,김민정,이규재,김한겸,조현득,채양석 大韓法醫學會 1999 대한법의학회지 Vol.23 No.2

Although it is known that hypothyroidism can cause cardiac dysfunction, it is very hard to find a case report on sudden death due to hypothyroidism. There are only two reported cases on mediline; one is about a 15-year-old girl who died suddenly of Hashimoto's thyroiditis and the other is about a 31-year-old man who also died suddenly of hypothyroidism associated with chronic lymphocytic thyroiditis. Recently we found a young woman who unexpectedly died while she was sleeping. She was diagnosed as hypothyroidism when she went to hospital about a month before she died. At autopsy there were roughly four abnormal findings; Hashimoto's thyroiditis, mild chronic active hepatitis, diverticulosis and accessory spleen. Trace of chlorpheniramine was detected in gastric remains and blood alcohol level was 0.37 percent. To our knowledge, this is the first case reporting sudden and unexpected natural death associated with hypothyroidism in Korea.

알칼리 처리에 의한 폴리에스테르 필름의 강도 및 염색성의 변화

오정숙,이광주,전정희 효성여자대학교 가정대학 학도호국단 1985 家政大論集 Vol.4 No.-

When polester fibers are hydrolyxed in alkaline solution, they dissolve successively from their surface and change their dyeability. We examined the weight loss ofpolyester films treated with NaOH solution under various conditions and the equilibrium.amount of disperse dyes absorbed in films. An uptake of dyes on films treated withan alkaline solution has beer discussed in relat'on to the changes of weight loss of films. The changes of weight loss increased linearly on hydrolyzing time because ofdissolving uniformly froml their surface of films. However. in high concentrations ofalkaline solution, the changes of weight loss increased drastically owing to OH-attackedto the inner regions of films. The tensile strength of hydrolysed films decreased a sodden drop when the weightloss were low. But it decreased gently when weight loss were high. The dye uptake of hydrolyzed films increased a very small amount below 20% ofweight loss. However, it increased remarkably above 20% of weight loss.

고속가공시 다중센서를 이용한 가공상태 감시 기술

김전하,강명창,김정석,나승표,김기태 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

The high hardened materials that are remarkable in aspects of durability have been used for die and mold industry. As the high hardened materials are hard to machine, the high-speed machining is essential to manufacture these materials. Currently, in the general turning and milling, experiments to the tool wear monitoring have studied, but those have not applied in high-speed machining. In this study, the cutting mechanism was analysed by the cutting force according to cutting conditions, and the parameters to monitor the tool wear were selected from the tendency of the cutting force and acceleration according to cutting length in the high-speed machining of the high hardened materials(STD11).

C-means 알고리즘을 이용한 마이크로 엔드밀의 상태 감시

권동희,정연식,강익수,김전하,김정석 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

Recently, the advanced industries using micro parts are rapidly growing. Micro end milling is one of the prominent technology that has wide spectrum of application field ranging from macro to micro parts. Also, the method of micro-grooving using micro end milling is used widely owing to many merit, but has problems of precision and quality of products due to tool wear and tool fracture. This study deals with condition monitoring using acoustic emission(AE) signal in the micro-grooving. First, the feature extraction of AE signal directly related to machining process is executed. Then, the distinctive micro end mill state according to the each tool condition is classified by using the fuzzy C-means algorithm, which is one of the methods to recognize data patterns. These result is effective monitoring method of micro end mill state by the AE sensing techniques which can be expected to be applicable to micro machining processes in the future.

중환자에서 동맥혈 가스분석 횟수와 그로인한 실혈량에 대한 연구

이석열,전철우,정영수,오희숙,마분란,이정미,정혜영,이만복,이길노 순천향의학연구소;Soonchunhyang Medical Research Institute 2000 Journal of Soonchunhyang Medical Science Vol.6 No.1

Background : Arterial blood gas analysis is the most comon exam in intensive care unit. In this study, the frequency of blood gas analysis and the amount of blood loss after Blood Gas Analysis in Intensive Care Unit were observed. Methods : From November 1999 to February 2000, 115 patients admitted to intensive care unit at Soonchunhyang university Kumi hospital were studied prospectively for the frequency of blood gas analysis and the amount of blood loss after blood gas analysis in Intensive Care Unit. Results : The mean value of frequency of blood gas analysis was 6.41±6.49 and the mean value of amount of blood loss after blood gas analysis was 0.78ml. This was lower than that of other foreign reports. The patients with ventilator therapy above 24 hours showed higher frequency of blood gas analysis than that of not applied ventilator patients. Pulse oxymetry was applied to all patients and the frequency of blood gas analysis was decreased due to the use of strict pulse oxymetry. Conclusion : Doctors and nurses in intensive care unit keep in mind that adequate blood sampling is needed for the decrease of blood loss. Education and protocol for the decrease of blood loss after arterial blood gas analysis may be necessary.

AE 신호를 이용한 회전형 압축기의 이상상태 감시

이감규,정지홍,김전하,강명창,김정석 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.5

The compressor has one of important roles in refrigeration cycle and it determines refrigeration efficiency and quality. This paper aims to monitor rotary compressors for room air conditioners by using Acoustic Emission(AE) technique. The reliability of rotary compressors has been evaluated through visual inspection on them after long term test. This paper describes methods for acquisition and processing AE raw signal to monitor the state of rotary compressor. A detecting method of abnormal compressor in real time is suggested and special-purpose monitoring system which can be applied to automatic manufacturing line is developed using one-chip microprocessor at low cost.