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.

난치성 전두엽 간질의 외과적 치료

김정목,김형일,김근수,김철진,이정청,이민철 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.11

Recent advances of neuroimaging and electrophysiological monitoring technique have contributed in improving the surgical outcome of frontal lobe epilepsy. The authors have analysed 36 consecutive cases of intractable frontal lobe epilepsy that were treated at our institute between September. 1992 and December, 1995 to determine the clinical, electrophysiological, and neuroimaging characteristics as well as to delineate the efficacy of surgical treatment in improving the seizure outcome. The patients consisted of 19 males and 17 females. The mean age of the seizure onset and the mean duration of epilepsy were 14.9 and 11.6 years, respectively. Magnetic resonance imaging(MRI) showed no lesion in 9 patients and pathological lesions in 27 patients. The types of the lesions observed included primary brain tumor, mostly low-grade glioma in 10 patients, cortical dysplasia in 4, posttraumatic scar in 4, neocortical gliosis in 3, cyst in 3, and postencephalitic atrophy in 3. Intracranial recordings were performed in 23 cases to determine the epileptogenic zone. The surgical outcome was graded according to Engle’s Classification as Class A in 20 patients. Class B in 2, Class C in 9, and Class D in 5. The surgical outcome was promising regardless of the presence or the absence of the lesion on MRI, invasive recording, age of seizure onset, and duration of epilepsy.

바나듐 유동 전지용 나노 유체의 전기 화학적 반응에 대한 연구

김정명(Jung Myung Kim),박희성(Hee Sung Park) 대한기계학회 2020 大韓機械學會論文集B Vol.44 No.7

바나듐 산화/환원 유동 전지(VRFB: Vanadium Redox Flow Battery)의 전기적 용량 및 수명 증대를 위한 다중 벽 탄소 튜브 콜로이드 용액인 나노 유체를 제조하였으며, 바나듐 전해액에 적합한 초음파 분산 방법을 적용한 나노 유체의 전기 화학적 성능 평가를 위해 단일 셀 유동 전지 평가 시스템으로 62회의 충/방전 사이클 실험을 진행하였다. 본 연구에서 평가된 나노 유체의 에너지 밀도는 0.1wt% (37.62Wh/L) > 0.2wt%(34.77Wh/L) > 0.05wt%(34.17Wh/L) > pristine(29.93Wh/L)의 순서를 보였으며, 용량 감소율은 0.1wt%(0.5%) > 0.05wt%(7.8%) > 0.2wt%(10.7%) > pristine(15.6%) 순서로 확인되었다. 기존 graphite felt 전극과 MWCNT 나노 입자 분석을 위해 XRD와 Raman 분광법을 사용하였다. 본 연구는 시스템에 따라 다양한 최적 중량비가 존재함을 보였으며, 연구에 사용된 단일 셀 시스템의 최적 콜로이드 전해액의 나노 입자 중량비는 0.1wt%임을 밝혔다. The nanofluid was prepared by dispersing nanoparticles to increase the capacitance and lifespan of a vanadium redox flow battery. To evaluate the performance of the nanofluid, a single cell redox flow battery system was tested with 62 charge/discharge cycles. The energy density of the nanofluids estimated in this study was 0.1 wt (37.62 Wh/L) > 0.2 wt (34.77 Wh/L) > 0.05 wt (34.17 Wh/L) > pristine (29.93 Wh/L). The capacity reduction rate decreased in the following order: 0.1 wt (0.5) > 0.05 wt (7.8) > 0.2 wt (10.7) > pristine (15.6). X-ray diffraction, Raman, and energy-dispersive X-ray spectroscopy were used to analyze existing graphite felt and multiwalled carbon nanotube nanoparticles. The nanoparticle content of the optimal nanofluid in the single cell system used in this study was 0.1 wt.

동적 그룹에 적합한 안전하고 효율적인 그룹키 동의 프로토콜

김기성(Kim Ki Sung),김정윤(Kim Jung Yoon),최형기(Choi Hyoung Kee) 한국통신학회 2008 한국통신학회 학술대회논문집 Vol.2008 No.7

석면관련 폐질환의 진단에 있어서 흉부고해상도전산화단층촬영검사(HRCT)의 유용성

이현재,손지언,,홍영습,,이영일,예병진,유창훈,정갑열,김상훈,임형준,장은철,김정만,김준연 大韓産業醫學會 2006 대한직업환경의학회지 Vol.18 No.2

목적: 석면에 노출된 근로자에서 석면관련 폐질환의 양상을 분석하고 진단에 있어 HRCT의 유용성을 연구하여 석면에 대한 의학적 감시프로그램의 개발에 기여하고자 하였다. 방법: 석면에 직접 노출되는 작업자 68명과 간접 노출되는 작업자 94명 등 총 162명에 대해 OSHA 석면 표준, 의학적 감시 프로그램에 따라 단순 흉부방사선검사, 폐활량검사 및 우리나라 실정에 맞게 일부 수정한 의학적 설문지를 통해 면접조사의 방식으로 환자에 관한 정보를 수집하였으며, 자료의 신뢰성을 확보하기 위하여 면접조사는 1달 이상의 기간을 두고 2차례에 걸쳐 실시된 후 확인, 수정하였다. 또한, 석면관련 폐질환을 확진하기 위하여 HRCT를 추가적으로 실시하였다. 결과: HRCT결과 석면관련 폐질환의 유병율은 162명의 근로자중 17명으로 10.5%였는데, 직접 노출군에서 10명 (14.7%), 간접 노출군에서 7명 (7.4%)이었다. HRCT와 비교할 때 단순 흉부방사선검사의 민감도와 특이도는 각각 70.6%와 98.6%이었고, 양성 예측도와 음성 예측도는 각각 85.7%와 96.6%으로, HRCT는 단순흉부방사선검사에 비해 민감도가 높아 초기 석면관련 폐질환을 진단하는데 효과적이었다. 석면관련 폐질환의 진단에 있어 HRCT와 폐활량검사 사이에 유의한 관련성이 관찰되었다. HRCT 결과 석면관련 폐질환의 유무와 의학적 설문조사 결과의 빈도분석을 실시한 결과, 유의한 변수는 작업기간, 흡연량, 호흡기질환의 과거력, 기침, 호흡곤란이었다. 결론: HRCT는 석면관련 폐질환의 진단에 있어 단순 흉부방사선검사와 비교하여 민감도가 높아 초기 진단에 유용하므로 단순 흉부방사선선검사 결과 석면관련 폐질환소견을 보일 때뿐만 아니라, 정상소견을 보이더라도 폐활량 검사결과와 근무력, 흡연력, 호흡기질환의 과거력, 기침, 호흡곤란 등의 호흡기 증상을 참고하여 HRCT검사를 고려해야 한다. 또한, 본 연구에서 관련성이 없었던 요인들에 대해서도 향후 연관성을 규명하는 광범위한 전향적 연구가 필요하다. Objectives: This study was carried out to improve the medical surveillance program of workers exposed to asbestos by examining the usefulness of High Resolution Computed Tomography (HRCT) in the diagnosis of asbestos-related lung disease. Methods: The study subjects comprised 162 workers in a ship-repairing yard, 68 of whom had been directly exposed to asbestos and 94 indirectly exposed. The 'Occupational Safety & Health Administration (OSHA) asbestos standard, medical surveilance program' and HRCT were conducted to analyze the aspects of the asbestos-related lung disease. The OSHA asbestos standard, medical surveilance program consists of simple chest x-ray, spirometry and medical questionnarie. Results: Seventeen (10.5%) of the 162 subjects, 10 (14.7%) directly exposed and 7 (7.4%) indirectly exposed, revealed asbestos-related lung disease on HRCT. The sensitivity and specificity of simple chest x-ray for asbestos-related lung disease were 70.6% and 98.6%, and the positive and negative predictive values were 85.7% and 96.6% respectively, as compared with HRCT, HRCT was an effective diagnostic tool especially to detect early asbestos-related lung disease. The study results indicated a relative significant association between the results of spirometry and HRCT. The variables significantly associated with asbestos-related lung disease on HRCT were work duration, smoking history (pack-years), past history of respiratory disease, cough and dyspnea. Conclusions: In the diagnosis of asbestos-related lung disease, HRCT should be considered not only for workers with positive findings on simple chest x-ray, but also workers with specific findings on spirometry, occupational history, smoking history, and past history of respiratory disease, or with respiratory symptoms such as cough and dyspnea.

GaAs반도체의 오믹접합에 관한 연구

김영중,김형준 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.5 No.-

Rolandic Cortical Dysplasia : 증례보고 Case Report

김형일,정채경,최하영,Palmini, Andre,이민철,이정청 대한신경외과학회 1994 Journal of Korean neurosurgical society Vol.23 No.6

The advent of MRI enables us to make an in-vivo diagnosis of cortical dysplastic lesions which are highly epiletogenic and show the variety of seizure patterns. Authors report a case of rolandic cortical dysplasia who had highly intractable focal motor clonic seizures. Invasive recording with subdural grid was very helpful in delinating the epileptogenic area as well as in functional mapping of eloquent areas. Total removal of dysplastic lesion could treat this highly intractable epilepsy successfully.

상표확장의 정보전이 이론과 신념변화모형에 관한 연구

김형길,정구도 제주대학교 관광과경영경제연구소 2002 産經論集 Vol.17 No.-

원격탐사를 위한 병렬계산 기법

김형중,장태정,김희원,김형수,이정문,장순자 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

원격탐사에 사용되는 편미분방정식을 고속으로 풀기 위한 기법을 프로그래밍하고 성능을 향상시킬 수 있는 방법을 제시했다. 미지수가 30만개 이상되는 복소수(non-Hermitian) 행렬의 해를 구하는 프로그램을 작성했다. 이 프로그램은 C와 PVM에 기반을 두고 있다. 수렴속도를 향상시키기 위해 대각 스케일링을 이용했다. 통신속도의 개선을 위해 데이터 압축 기법을 이용했다. 수렴속도를 측정 제시함으로써 실제 문제 적용에 참고할 수 있다. Network-based computing with cluster of personal computers or workstations recently has become an important and successful technique. Network-based computing enables fast computation and resolves short of storage with computers on the desks. Cluster of inexpensive computers offers them aggregated computing power and storage to challenge very large-scale problems. Iterative solvers are used for the large sparse linear systems. Preconditioners accelerate the rate of convergence of the iterative solvers. However, parallelization accelerate the rate of convergence of the iterative solvers. However, parallelization of preconditioners is far from satisfaction so far. Thus, the simplest diagonal scaling is a good alternative for improved convergence and easy parallelization. In order to reduce communication overhead, a data compression technique is considered. Data communication time can be reduced at the cost of convergence rate. MATLAB simulation result is given in this paper. This method is effective to cluster of computers connected through slow networks.

인공 대기오염 조건에 의한 종이 시트의 열화 거동

김형진,오정수,조병묵 동국대학교 생명자원과학대학 연습림 2000 연습림논문집 Vol.- No.6

Paper is an important material being considered as a contributor for the development and succession of human culture. With the introduction of mass production system by fourdrinier paper machine, the addition of lots kinds of chemicals and additives is necessarily required for controlling papermaking process. The modern machine-made paper has a irreversible problem for acidification or deterioration of paper before the passage of time around 100 years, due to the chemical additions. The deterioration factors of paper can be divided by several classes, such as factors by raw materials of pulp, by papermaking processes, and by external environment. Among these, some factors occurring aging in paper are temperature, moisture, and air pollutant materials. In particular, air pollution, like SO_2 and NO_2 by industrial and automobile origins has been a topic of focusing attentions for preservation of an old books. In this study, the conditions of artificial air pollutants and heat acceleration were controlled in special gas exposure system and weather-o-meter. The aging treatment was carried out in three kinds of commercial paper prepared with different types of fibrous material. The aging behaviors of paper by the factors of temperature, moisture, sulfur dioxide or nitrogen dioxide were investigated and analyzed from the results in physical and chemical properties of paper.