한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

粘性土의 反復壓密特性에 關한 硏究

鄭哲源,權俊五,鄭永同 朝鮮大學校 工科大學 1974 論文集 Vol.3 No.-

Up until today, there are not a few problems to be applied in the course of the analysis of consolidation characteristics of cohesive soil under repeated loads. As this consolidation is belived to occur on road subgrades as well as on railway bases when the latters are under traffic loads, in the ground under periodic stresses of oil tanks, docks, and occur on clay layers under fluctuating condition through ground -water-level, the consolidation sinkage is not the same as that of static stress. This consolidation sinkage is understood to be designed in the light of repeated stress.

적응관측기를 이용한 SPMSM의 속도 및 위치 센서리스 제어

정택기,이정철,이홍균,정동화 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

This paper is proposed to position and speed control of a surface permanent magnet synchronous motor(SPMSM) drive without mechanical sensor. An adaptive state observer is used for the mechanical state estimation of the motor. The observer is developed based on a nonlinear model of the SPMSM, that employs a d-q rotating reference frame attached to the rotor. A adaptive observer is implemented to compute the speed and position feedback signal. The validity of the proposed sensorless scheme is confirmed by various response characteristics.

경피적 자궁동맥 색전술로 치료한 산후 출혈 1례

정명철,김호성,김경철,노지현,고재환,김용봉,권동일 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Postpartum hemorrhage remains one of the leading causes of maternal deaths. The major causes of postpartum hemorrhage include uterine atony, retained placental fragment, placenta accreta, and lower genital tract lacerations. Conservative treatment is based on administration of uterotonic drugs, vaginal packing, and surgical repair of genital tract lacerations. When bleeding fails to respond to conservative treatment, surgical ligation of uterine vessels or hemostatic hysterectomy is performed. We present a case of postpartum bleeding treated by selective uterine arterial embolization with a brief review of previous literatures of postpartum hemorrhage & uterine arterial embolization.

치과병원에서 사용되는 진단영상에 대한 JPEG 2000 압축률에 대한 평가

정기훈,한원정,유동수,최순철,김은경 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Purpose : To find out the proper compression ratios without degrading image quality and affecting lesion detectability on diagnostic images used in dentistry compressed with JPEG 2000 algorithm. Materials and Methods : Sixty Digora periapical images, sixty panoramic computed radiographic (CR) images, sixty computed tomographic (CT) images, and sixty magnetic resonance (MR) images were compressed into JPEG 2000 with ratios of 10 levels from 5 : 1 to 50 : 1. To evaluate the lesion detectability, the images were graded with 5 levels (1: definitely absent; 2: probably absent; 3: equivocal; 4: probably present; 5: definitely present), and then receiver operating characteristic analysis was performed using the original image as a gold standard. Also to evaluate subjectively the image quality, the images were graded with 5 levels (1: definitely unacceptable; 2: probably unacceptable; 3: equivocal; 4: probably acceptable; 5: definitely acceptable), and then paired t-test was performed. Results : In Digora, CR panoramic and CT images, compressed images up to ratios of 15 : 1 showed nearly the same lesion detectability as original images, and in MR images, compressed images did up to ratios of 25 : 1. In Digora and CR panoramic images, compressed images up to ratios of 5 : 1 showed little difference between the original and reconstructed images in subjective assessment of image quality. In CT images, compressed images did up to ratios of 10 : 1 and in MR images up to ratios of 15 : 1. Conclusion : We considered compression ratios up to 5 : 1 in Digora and CR panoramic images, up to 10 : 1 in CT images, up to 15 : 1 in MR images as clinically applicable compression ratios.

전문가 시스템과 유한요소법에 의한 열간단조의 공정설계

정영철,이동근,박종진 弘益大學校 科學技術硏究所 1999 科學技術硏究論文集 Vol.10 No.1

In general, a forging product is produced through buster, blocker and finisher processes. The blocker, a transient shape between the buster and the finisher, is to ease the metal flow in the finisher dies. In general, as the finisher shape becomes complicated, the blocker design becomes quite difficult. In the present study, an expert system is developed for the blocker die design of axisymmetric hot steel forging. It is a rule based system written in Fortran and AutoLISP, operating on a personal computer. In this paper, the major rules considered in the system are summarized and several blockers designed by the system are discussed with results of rigid viscoplastic finite element analysis.

생리 활성 세라믹 분말이 첨가된 포장용 LDPE 필름의 새로운 에틸렌 평형 용해 모델

류동완,정재철,심승우,박찬영 전남대학교 촉매연구소 2000 觸媒硏究 論文集 Vol.21 No.-

This work investigates a new model that predicts the equilibrium solubility of gaseous component with polymer film. The new model regards the gas concentration in fluid phase as depressing factor in desorption from the surface of the film. The final mathematical form describes actual observation well with its second order form. The over all figure of the equilibrium solubility is sigmoid that one sees frequently in experiments. The only disadvantage of this model is the bulk concentration appears in denominator that induces the expression becomes infinite if the concentration is none. Insertion of one constant added to the concentration term in the denominator defeats this shortcoming. The following is the mathmatical form of the net rate of dissolution and the equilibrium solubility, respectively. □ Also, this paper presents the logical method obtaining the parameters from the experimental equilibrium data for the ethylene dissolution in LDPE film that had incorporated a ceramic powder with selective gas permeability. Finally, the dependency of the equilibrium parameters, KA, Cmax, the others to the weight fraction of the powder and appears to be linear and presented to follow : The parameters were calculated by soluble equilibrium constant, KA, maximum soluble concentration, Cmax and soluble rate constant, k+ for ethylene gas permeated through LDPE packaging films containing the ceramic powders 0∼6wt% at 20℃, the above model being applied. The values showed 1.45×106∼3.70×106[(㎤/mol)2], 2.30×10-3~2.92×10-3 [mo1/㎠sec]and 0.273∼0.405[㎤/mol sec], respectively.

각종 분유내의 불소 농도와 영아 불소 섭취에 관한 연구

김정욱,손동수,김종철 大韓小兒齒科學會 1995 大韓小兒齒科學會誌 Vol.22 No.1

Since the effect of fluoride on the dental caries was known, the fluoride supplement has been recommended when the natural fluoride is unavailable or below the optimal range. On the other hand, it is well known that the overdose of fluoride results in acute and chronic toxicity, expecially dental fluorosts. So, to estimate the fluoride intake of the infant and the need of fluoride supplementation, the author measured the fluoride concentration of some bottled waters, human milk, cow'a milk, and baby formula diluted with distilled deionized water and 0.8 ppm fluoride water, by means of the modified HMDS diffusion method and the fluoride ion specific electrode. The obtained results were as follow : 1. The fluoride concentration of the soy-based infant formula was 0.25±0.10 ppm, and that of milkbased infant formula was 0.05±0.02 ppm. The difference in the fluoride concentration between the soy-based and the milk-based infant formula was statistically significant(p<0.01). 2. In the case that the infant is fed with the human milk and /or cow's milk exclusively, appropriate fluoride supplementation is needed regardless of the fluoride concentration of the municipal water. 3. The fluoride intake seems to be optimal when the infant is fed with some soy-based infant formula even though the municipal water is not fluoridated. In that case fluoride supplementation is unnecessary. But fluoride supplement is needed when the infant is fed with milk-based baby formula in the nonfluoridated area. 4. The fluoride intake of the infant is beyond the optimal range when the infant is fed with baby formula diluted with the fluoridated municipal water.

컨버터로 제어되는 유도전동기 드라이브 시스템의 손실 모델링

정동화,이정철,박기태,이홍균 순천대학교 1999 순천대학교 자연과학논문집 Vol.18 No.2

An accurate loss model of induction motor drive controlled by the converter is proposed. Steady state fundamental and hamonics loss characteristics, besides the dynamics of the machine are analyzed and incorporated in the model, resulting in a new synchronous frame dynamics d-q equivalent circuit. The converter system has been modeled accurately for condition and switching losses.