운동이 백서 스테로이드 근병증에 미치는 효과

박상준,이민철,김세종,박상준,이민철,김세종 대한신경과학회 1999 대한신경과학회지 Vol.17 No.5

뇌혈관질환과 심근경색증에 관련된 요인의 비교분석

박종구,김헌주,박금수,이성수,장세진,이은경 연세대학교 원주의과대학 1994 원주의대논문집 Vol.7 No.1

일부 생산직 근로자의 소음과 사회심리적 요인이 혈압에 미치는 영향

박종구,강명근,차봉석,고상열,장세진,고상백 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.2

This study was conducted to assess the effects of noise exposure and psychosocial factor on blood pressure in manufacturing workers. The study subjects are 414 workers(243 males, 171 females) employed at the noisy department. The mean age of low exposed group(<85dB) was 34.65±9.53 years, and that of high exposed group(≥85dB) was 36.37±11.15 years. The difference in mean age was not significant. The mean and distribution of working duration, smoking status, drinking status were not significantly different between two groups. The mean systolic blood pressure of the low exposed group was 120.01±12.06 mmHg, and that of high exposed group was 126.27±13.84mmHg. The mean diastolic blood pressure of the low exposed and the high exposed group were 77.18±10.83 mmHg, and 83.46±11.22mmHg respectively. These differences of blood pressure were statistically significant(p<0.05). The workers in noisy department have significantly less work environmental satisfaction, higher job demand, and higher social support. The mean values of psychosocial distress were higher in the workers of the noisy department, but the difference was not statistically significant. This study was to speculate whether the work environmental satisfaction and social support modify the association between the noise exposure level and the blood pressure. The result showed that work environmental satisfaction could not modify the association between the blood pressure and the noise exposure. Social support at work did not modify the association. Furthermore, we evaluated the high job strain from a combination of ratio of the high job strain group for hypertension in diastolic blood pressure were statistically significant, but not in systolic blood pressure. Hierarchical multiple regression analysis was used to determine whither the independent variables contributed to explaining the blood pressure. After controlling for possible confounders, we found that the noise exposure level was a correlated of the diastolic blood pressure. But no association between the noise exposure level and the systolic blood pressure. No significant result was found for psychosocial factor.

一部 樂器의 演奏音에 의한 暴露歷이 聽力에 미치는 影響

박종안,장봉기,이종화,안규동,이영세 순천향대학교 산업의학연구소 1997 순천향산업의학 Vol.3 No.1

This study was carried out to evaluate the effect of playing musical instruments on hearing threshold level from May to October, in 1997. Pure tone audiometric tests was provided to musical instruments playing group of total 117 subjects(Samullnori; 35, military band; 25, symphony orchestra; 46, piano; 11), and reference group of total 7,477 subjects, selected after excluding workers with history of ear disease, of ototoxic drug administration, of noise induced hearing loss at workplace in Pohang industrial area. In addition, noise exposure levels of musical instrument players were assessed by noise dosimetry(exchange rate; 5dB, threshold level; 80dB, criterion level; 90dB), and produced age-adjusted hearing threshold level(=hearing threshold level of musical instrument player - hearing threshold level in same age of normal population group). The age-adjusted hearing threshold levels were analyzed by musician's career. The results were as follows; 1. The hearing threshold level of reference group was revealed more increased as within 4.98dB to 6.89dB at 1 KHz and within 5.26dB to 14.46dB at 4 KHz by ages than "the Standard of Age-adjusted Hearing Loss by Frequency(OSHA)" used for special health examination in the Ministry of Labour. 2. Equivalent continuous sound exposure level (Leq) by the group of instrumentalist was as following; within 104.95 to 112.62dB in samullnori, the highest, within 100.18 to 103.49dB in military band, within 77.00 to 82.74dB in symphony orchestra and 81.54dB in piano, the lowest. Playing maximum sound level by each musical instrument was as following; 122.8dB in Kkwaenggwari, the highest, 122.7dB in Changgo, 121.8dB in Alto saxophone, 115.5dB in Trumpet, 119.2dB in Horn, 112.8dB in Pungmul Buk and Ching, 112.5dB in Clarinet. 3. Average age-adjusted hearing threshold levels of instrumentalists were -0.65±6.38dB in left ear, -0.92±6.59dB in right ear at 1 KHz, and -1.14±12.88dB in left ear, -1.53±12.77dB at 4 KHz, which were better than normal, but the average age-adjusted hearing threshold levels of Samullnori players were 1.23±5.22dB in left ear, 1.94±6.91dB in right ear at 1KHz, and 8.40±15.75dB in left ear. 7.13±14.97dB in right ear at 4KHz, which were worse than normal. 4. Hearing threshold level in Samullnori players was increased with their career at 4 KHz, especially it increased rapidly when the musicians had played over 10years. It showed that there was a significant relationship between hearing threshold level and the career (P<0.01).

MgO에 담지된 촉매에서의 메탄의 짝지움 반응에 관한 연구

박종걸,김영채,문세기 한양대학교 에너지·환경기술연구소 1997 에너지·環境技術論文集 Vol.3 No.-

연속 흐름식 상압 반응기에서 메탄과 산소를 반응물로 하고 MgO,CaO,γ-Al₂O₃담체에 활성물질인 Li₂CO₃를 담지하여 제조한 촉매를 사용하여 반응 조건을 변화시키면서 메탄의 oxidative coupling 반응을 행하였다. Li₂CO₃담지시 활성이 크게 향상되었으며 MgO, CaO에는 9㏖%,γ-Al₂O₃에는 17㏖%를 담지 하였을 때 수율이 가장 좋았으며, 활성은 MgO>CaO>γ-Al₂O₃순으로 나타났다. Li₂CO₃(9㏖%)/MgO, CaO 촉매에서 최적 반응 조건은 온도 1030K P(CH₄)/P(O₂)=1, 접촉시간(W/F)은 0.0067g-cat.min/㎖였다. In the plug-flow at atmospheric reactor, the oxidative coupling of methane was performed with methane and oxygen using the catalysts prepared by impregnation of MgO, CaO,γ-Al₂O₃with Li₂CO₃in the various reaction conditions. The activity was enhanced at impregnation Li₂CO₃. The yield was utmost at 9㏖% in MgO, CaO and 17㏖% in γ-Al₂O₃. The activity was in order of MgO, CaO,γ-Al₂O₃. The optimum reaction condition was 1030K, P(CH₄)/P(O₂)=1, and 0.0067g-cat.min/㎖ in Li₂CO₃(9㏖%)/MgO,CaO catalyst.

흡연에 의한 급성 호산구성 폐렴 2예

박종빈,김학렬,주현준,유태양,신성남,신정현,송정섭,황기은,김소영,양세훈,정은택 圓光大學校 醫科學硏究所 2008 圓光醫科學 Vol.23 No.2

최근 흡연을 시작한 젊은 성언에서 급성 호산구성 폐렴의 발생에 대한 증례가 보고되고 있다. 급성 호산구성 폐렴은 대개 발열을 동반하기 때문에 초기에는 감염성 폐렴으로 잘못 진단, 치료되는 경우가 많다. 아직 정확한 병태 생리 및 조직학적 소견은 밝혀져 있지 않지만 병력 청취 및 임상 양상, 방사선 소견의 관찰을 통해 급성 호산구성 폐렴을 의심하고, 진단을 위해 기관지 폐포 세척액 검사를 시행한다면 좀 더 쉽게 진단 내릴 수 있을 것이다. 본 저자들은 최근 처음 시작한 흡연에 의해 발생한 급성 호산구성 폐렴을 진단하고, 스테로이드를 투여하여 성공적으로 치료한 환자 2예를 경험하였기에 이를 문헌 고찰과 함께 보고하는 바이다. Acute eosinophilic pneumonia(AEP) is characterized by acute febrile respiratory illness associated with diffuse pulmonary infiltration and pulmonary eosinophilia. The specific etiology for acute eosinophilic pneumonia is elusive. By some investigators, cigarette smoking is suggested as a causative substance which can cause AEP. In recent, the authors experienced two cases of AEP following cigarette smoking. Both cases had characteristic features including age around 20 years, new onset smoking before occurance of AEP, diffuse infiltration on chest radiography, pulmonary eosinophilia based on bronchoalveolar lavage and acute improvement after steroid therapy. These clinical features are resemble with previous smoking induced AEP case reports. Base on these clinical features, cigarette smoking associated AEP could be diagnosed more easily.

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.

피로와 의료이용, 업무상 사고 및 질병결근

장세진,고상백,강동묵,김성아,정진주,이철갑,강명근,현숙정,조정진,차봉석,박종구 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Objectives: This study examined the relationship of fatigue to medical utilization, occupational accident and sickness absence. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project, 2002~2004). A total of 30,146 employees categorized within the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were recruited. A structured-questionnaire was used to assess the participants' sociodemo-graphics, job-related factors, health-related behaviors, personality trait, self=perceived fatigue (MFS) and the frequency of medical utilization, occupational accident and sickness absence. Data on medical utilization and occupational accident were confirmed from company health records. Chi-square test and logistic regression analysis were used to elucidate the relationship of self-perceived fatigue to medical utilization, occupational accident and sickness absence. Results: In logistic regression analyses, self-perceived fatigue was associated with medical utilization (outpatient), occupational accident and sickness absence although the strength of the associations was higher in the blue collar workers except for medical utilization. For medical utilization, the white collar worker's adjusted odds ratios of outpatient utilization for workers scoring in the third quartile and the highest quartile, compared to workers scoring in the lowest quartile were 1.50 (95% CI: 1.20-1.87) and 2.16 (95% CI: 1.69-2.75), respectively. The blue collar workers' adjusted odds ratios of outpatient utilization for workers scoring in the second (OR: 1.23, 95% CI: 1.06-1.43), third (OR: 1.42, 95% CI: 1.22-1.66) and highest quartile (OR:1.83, 95% CI: 1.55-2.17), respectively, compared to workers scoring in the lowest quartile were statistically significant. However, no associations were found between fatigue and inpatient utilization for either the white or blue collar workers. The blue collar workers' adjusted odds ratios of being injured for workers scoring in the second, third and highest quartile were 1.41 (95% CI: 1.00-2.00), 1.57 (95% CI: 1.10-2.22) and 2.41 (95% CI: 1.69-3.44), respectively, compared to those scoring in the lowest quartile, but, those of the white collar workers were not significant. There was more likely to an increased risk of sickness absence in workers scoring in the second, third and highest quartile compared to those scoring in the lowest quartile in both white and blue collar workers, but the magnitudes of risk were higher in the blue collar workers than the white collars workers. Conclusion: This result suggests that fatigue is a determinant predictor of medical utilization, occupational accident and sickness absence, and that the pattern of risks for the three outcomes differs according to the occupational type. Some limitations of this study and considerations for future study were also discussed.

극좌표계를 이용한 구륜이동로보트의 기구학 모델 변환과 기준모델 적응제어에 기초한 경로추적 제어기 설계

문종우,김종수,박세승 조선대학교 전자정보통신연구소 2002 電子情報通信硏究所論文誌 Vol.5 No.2

This paper presents the kinematic model and the design of a model-reference adaptive controller for wheeled-mobile robots(WMRs) with 2 d.o.f. We derive the forward kinematics and the inverse kinematics to calculate the wheel-velocity and body-velocity. The controlled variables are represented in the polar coordinate so that the number of the controlled variable can be reduced to the same number as the control input. A controller is proposed for path tracking, and then controller parameters are modified by adaptation law based on model-reference adaptive control(MRAC) each step. The designed adaptive controller is analyzed, and its stability and convergence are proved. Simulation is conducted to evaluate the control system and the results are shown.

구륜이동로보트의 기구학적 보정과 모터 제어기의 가속도 제약을 고려한 속도 궤적의 설계

文鍾寓,白祥煜,朴世承 朝鮮大學校 電子情報通信硏究所 2003 電子情報通信硏究所論文誌 Vol.6 No.2

This paper presents the kinematic correction method for wheeled-mobile robots with 2 d.o.f. and a design of the velocity trajectory for wheeled-mobile robots' line-travelling. We derive the relative wheel-weight and the absolute wheel-weight to correct radius of both wheels. And we use the curvature angle to correct displacement of wheel base. We show that wheeled-mobile robots can't move along the straight-line perfectly and prove that it is attributed to the acceleration constraint of motor controllers and the velocity trajectory have to get a change of velocity in order that wheeled-mobile robots may converge to the straight line. To prove justification and efficiency of methods proposed in this paper, we experiment on the wheeled-mobile robots with 2 d.o.f. and discuss results.