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.

비글개에서 분만 후 자궁수복의 연속적 초음파상

손형원, 김홍석, 김형진, 김일화, 이기창, 이청산, 강현구 충북대학교 동물의학연구소 2006 Journal of Biomedical and Translational Research Vol.7 No.2

본문참고

백색부후균 전처리에 의한 목재 칩의 Biopulping

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

Pulping process is to mainly obtain lignocellulosic fibers for papermaking from wood resources. Three types of pulping method have been basically employed, such as chemical pulping, mechanical pulping, and their combination methods. Biopulping technique has been mainly applied in mechanical pulping by pretreatment of white-rot fungi into the ultrastructure of wood cell wall. The main purpose of biopulping is to improve the pulp qualities, paper properties, and to reduce the energy costs and environmental impact, compared to traditional pulping systems. Nowadays, biopulping is frequently tried in chemical pulping operation for environmental concept, fiber modification, improvement of physical properties of paper and economic savings. The pretreatment of white-rot fungi prior to chemical pulping could affect the swelling and softening of wood cell walls by the behaviors of modification and depolymerization of ligin compounds. This study was carried out to investigate the effectiveness of biological treatment to wood chips by white-rot fungus and its structural change of lignocellulosic fiber via kraft pulping. A rotary bioreactor was applied for pretreatment of biological action. The treatment of white-rot fungus was shown in weight loss of chips. After bio-kraft pulping, kappa number and total yield of pulps were measured, and reduced. Freeness(CSF) values were also decreased. Whereas brightness values were increased, compared to untreated control. The physical strength of handsheets was shown a slight increase in tensile, tear, burst, and folding endurance, with bio-treatments.

로봇 매니퓰레이터의 선형모델을 이용한 다변수 제어기 설계

이준형,김정주,강진식 濟州大學校工科大學産業技術硏究所 1999 尖端技術硏究所論文集 Vol.10 No.1

In this paper, we present a multivariable controller for the robot manipulator. By using the linearized model, calculation time is reduced because of the linearized model could relax the nonlinear property. Since the linearized model improve the influence of the modification of the robot dynamic parameters, errors, caused by the variation of dynamics such as the unknown load of a manipulator, nonlinear properties are compensated. By this reason, The presented controller can be adopted in the industrial application. An usual multivariable controller, using pole placement, has relatively a large tracking errors. In order to obtain small tracking errors, rapid response, and stabilize the robot manipulator, the linearized dynamics of the manipulator and PID controller structure are used in the presented controller which is designed via pole placement algorism. To show the suggested controller have rapid trajectory tracking property, and it is not affected by the unknown load and load variation, the simulation results of the 2-link robot manipulator are presented.

로봇 매니퓰레이터의 선형모델을 이용한 다변수 제어기 설계

이준형,김정주,강진식 濟州大學校 産業技術硏究所 1999 산업기술연구소논문집 Vol.10 No.1

In this paper, we present a multivariable controller for the robot manipulator. By using the linearized model, calculation time is reduced because of the linearized model could relax the nonlinear property. Since the linearized model improve the influence of the modification of the robot dynamic parameters, errors, caused by the variation of dynamics such as the unknown load of a manipulator, nonlinear properties are compensated. By this reason, the presented controller can be adopted in the industrial application. An usual multivariable controller, using pole placement, has relatively a large tracking errors. In order to obtain small tracking errors, rapid response, and stabilize the robot manipulator, the linearized dynamics of the manipulator and PID controller structure are used in the presented controller which is designed via pole placement algorism. To show the suggested controller have rapid trajectory tracking property, and it is not affected by the unknown load and load variation, the simulation results of the 2-link robot manipulator are presented.

개방형 원심압축기에서의 틈새크기에 따른 유동특성에 관한 실험적 연구

김진형,조강래 연세대학교 산업기술연구소 1994 논문집 Vol.26 No.2

The Pressure loss due to leakage flow is directly related to the tip clearance size of centrifugal impeller. The performance and the pressure distribution along the shroud casing are measured by using pressure transducer system for unshrouded centrifugal compressor at different size of tip clearance. The characteristic curves With respect to the size of tip clearance are presented as one curve regardless of rotational speed. As the size of tip clearance increases form 0.5mm through 2.0 mm, the values of pressure coefficient of characteristic curves decrease linearly due to the increase of leakage loss. The reduction rate of static pressure coefficients per 1 mm tip clearance is 0.04∼0.047, and the reduction rate per c/b₂is 0.28 evenly. The pressure coefficient for radial direction on the shround casing surface is presented as one curve regardless of rotational speed and decreases linearly. The reduction rate of pressure coefficient is nearly identical to that of characteristic curves.

셀레콕시브 및 그 합성유도체들의 항암활성 스크리닝

박정란,강진형,구효정,노지영,류형철,박상욱,고동현,조일환,이주영,황다니엘,김인경 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

Selective COX (cyclooxygenase)-2 inhibitors including celecoxib have been shown to induce apoptosis and cell cycle changes in various tumor cells. New inhibitors are recently being developed as chemomodulating agents. We evaluated celecoxib and screened 150 synthetic compounds for anti-proliferative activities in vitro. Effects of celecoxib on COX activity, cell growth, cell cycle distribution, and apoptosis induction were determined in A549 COX-2 overexpressing human non-small cell lung cancer (NSCLC) cells. The COX inhibition of celecoxib increased with concentration up to 82% at 1μM after 24 hr exposure. Forty μM and 50μM of celecoxib induce G_1 arrest, and TUNEL-positive apoptotic cells, respectively. Among 150 compounds, several compounds were selected for having greater COX-2 inhibitory activity and higher selectivity than celecoxib with growth inhibitory activity. Celecoxib showed concentration-dependent COX inhibitory activity, and ability to induce cell cycle arrest and apoptosis in human NSCLC cells in vitro. Among synthetic analogues screened, several compounds showed promising in vitro activity as COX-2 inhibitory anticancer agents, which warrant further evaluation in vitro and in vivo.

Descriptor 시스템 모델링 및 극배치 제어기 설계

김정주,이준형,강진식 濟州大學校工科大學産業技術硏究所 1999 尖端技術硏究所論文集 Vol.10 No.1

Many of the engineering systems such as electrical circuits, communication networks, power systems, aerospace systems and singular systems can be modelled by a descriptor system which is similar to the state space representation of the system. In this paper, we present a control algorithm for the descriptor system by using eigenstructare assignment. When the number of poles of the system changed due to the parameters variation, the system can be modelled by two subsystems as the one is static system and the other is dynamic. And two systems are connected serially by the manner that the one system output is connected to the input of the other system. The controller presented in this paper, designed by eigenstructure assignment, can treats such a singular system easily. To show the suggested controller has a good feature, we apply the presented controller to the inverted pendulum system.

7개 대학 병원에서 조사한 지역사회 폐렴의 원인균

정문현,김성민,강문원,최희정,정희진,이경원,한성우,송재훈,신형식,김의종,최강원,김민자,박승철,배현주,정윤섭,김준명,백경란,신완식,이규만,김양리 대한감염학회 1997 감염 Vol.29 No.5

목 적 : 폐렴은 많이 발생하면서 사망률이 크게 줄지 않는 질환이며, 이를 적절히 치료하기 위해서는 원인균의 상대적 빈도, 기저 질환에 따른 변화, 항균제 내성률, 사망에 관련된 인자들을 알아야 한다. 원인균의 빈도는 지역마다 차이가 있고 국내에서는 항균제 내성률이 높아 지역사회에서 발생한 폐렴을 치료하기 위한 경험적 항균제 선택에 도움이 되기 위해 서울 소재 6개 대학 병원과 천안의 1개 대학 병원이 참여하여 위의 사항들에 대해 조사를 하였다. 방 법 : 1995년에 내과에 입원했던 16세 이상 환자를 대상으로 했다. 퇴원 진단명이 폐렴 또는 폐결핵인 병록지을 찾았고, 이중에서 병원 감염을 제외하였다. 특이도를 높이기 위해, 이들 중에서 호흡기 증상이 있고 발열이나 저체온이 있으면서 흉부 X-선에서 이상 음영이 있는 환자만을 대상으로 했다. 폐결핵은 위의 기준에 입원 초기에 항균제 치료를 하고 입원 7일 이후에야 항결핵제가 투여된 경우만을 폐렴의 원인균으로 하였다. 혈액 배양에서 양성, 객담에서 항상균이나 M. tuberculosis가 증명된 경우, 혈청학적으로 항체가가 4배 이상 증가된 경우, 조직에서 원인균이 진단된 경우는 확정(definitive) 원인균으로 하였고, 객담에서 배양된 균이 그람 도말과 일치할때, 항결액제에 대한 반응으로 진단한 폐결핵, 단일 항체가 양성이고 이에 대해 항균제를 사용했을 때는 가능(probable) 원인균으로 정의하였다. 다세균 감염균은 각각 다 른 원인균으로 처리하였다. 임상 조사와 함께 임상병리과에서 S. pneumoniae, H. influenzae, M. catarrhalis, mycoplasma, 항상균에 대해 검사 의뢰 건수, 배양 양성수, 항균제 감수성 결과를 조사하였다. 결 과 : 폐렴의 증례 정의에 부합하지 않은 135명과 폐결핵의 정의에 해당하지 않는 230명을 제외하고 남은 246명의 평균 나이는 58.2세이고 남성이 142명(58.2%) 이었고, 71%의 환자에서 기저 질환이 있었다. 진단 방법의 시행 횟수는 혈액 배양 77.6%, 혈청 검사 18.3%, 기관지경 검사는 4.1%였고, 세균의 항원 검사를 한 예는 없었다. 원인균이 밝혀진 예는 77명(31.3%)이었다. 다세균 감염이 4명에서 있었고, 원인균의 상대적 빈도는 결핵 20명(확정 17, 가능 3: 6개 병원 자료), 폐렴구균 18(확정8 가능 10)명과 폐렴구균이 아닌 Streptococcus 3명 (모두 확정), H. influenzae 11명(모두 가능), 그람음성간균 11명(확정 7, 가능 4) (K. pneumoniae 8건), Mycoplasma 5명(확정 1, 가능 4), S. aureus 4명(확정 2, 가능 2), mucormycosis 1명(확정)이었다. 평균 입원 기간은 19일이고, 중환자실 입원률과 인공 호흡기 사용율은 각각 18%와 9.3%였다. 사망률은 13.8%였고 사망까지 평균 기간은 14.6일 이었다. 다변량 분석에서 사망을 예측할 수 있는 인자는 저체온과 빈호흡이었다. 임상병리과에서 배양되었던 모든 폐렴구균의 Penicillin 내성률은 서울 3개 병원에서 82-88%, 천안에서 72%였다. 폐렴 환자의 혈액에서 배양된 7주는 모두 Penicillin에 감수성이 있었다. K. pneumoniae 8주 모두 cefotaxime과 gentamicin에 감수성을 보였다. 결 론 : 후향적 조사이고 병원마다 원인균 진단에 차이가 있지만, 원인이 밝혀진 경우에는 결핵과 폐렴균이 흔하였고, 무균 부위에서 배양된 폐렴구균의 항균제 내성률은 낮았다. 원인이 밝혀지지 않은 경우가 많고, 혈청검사로 진단되는 원인균이 드물며, 분리균주가 적어 항균제 내성 정도를 추정하기 어려워, 이를 밝히기 위한 전향적 조사가 필요하다. Background : Community-acquired pneumonia (CAP) is one of the leading causes of mortality and morbidity, but its management is still challenging. The limitation of diagnostic methods to identify etiologic agents rapidly make it necessary to use empiric antibiotics in almost all patients, and furthermore the discovery of new respiratory pathogens and the emergence of antibiotic-resistant organisms pose difficulties to the selection of an empiric regimen. To clarify the factors necessary for the optimal choice of empirical antibiotics, such as the frequency of etiologic agents, the attributable rates to death and antimicrobial resistance rates in the community, six university hospitals in Seoul and one university hospital in Cheonan were participating in this study. Methods : medical records of adults (>15 years of age) hospitalized for CAP or pulmonary tuberculosis between April 1995 and March 1996, were reviewed. Patients who satisfied all of the following criteria were included in the study: (1) fever or hypothermia; (2) respiratory symptoms; and (3) pulmonary infiltrates on chest roentgenogram. To exclude cases of pulmonary tuberculosis whose roentgenographic features were so typical that it could be easily differentiated from conventional pneumonia, two additional criteria were required for inclusion: antibiotic treatment during the first week of hospital admission and initiation of anti-tuberculosis medications thereafter. Organisms isolated from sterile body sites, acid-fast bacilli or Mycobacterium tuberculosis isolated from sputum, pathogens diagnosed by a 4-fold rising titer of antibodies to “atypical”pathogens, or pathogens revealed by histopathology were defined as definitive cause of pneumonia; isolates from sputum withcompatible Gram stain, pathogens diagnosed by a single diagnostic titer plus use of a specific antimicrobial agent, or tuberculosis diagnosed by clinucal response to anti- tuberculosis medications were considered probable cause of pneumonia. The records of the clinical microbiology were reviewed for isolates of S. pneumoniae, H. influenzae, M. catarrhalis, Mycobacterium or acid-fast bacilli, and Mycoplasma. Then the frequency of these agents, antimicrobial resistance rates of resiratory pathogens from all body sites, and their clinical significance were evaluated. Results: After excluding 365 patients (230 with pulmonary tuberculosis and 135 with CAP) who were screened for inclusion but did not meet the inclusion criteria,246 persons were enrolled in this study. Their mean age was 58.2 years old with slight male predominance (58.2%), and 171(71%) patients had underlying illnesses. Blood cultures were performed on 191 (77.6%) patients and serologic tests on 44(18.3%) patients. The etiologic agents were identified in 31.3%, and the list of individual agents, in decreasing order, was pulmonary tuberculosis (17 definite and 3 probable: data of six hospitals), S. pneumoniae (8 definite and 10 probable), non-pneumococci (3 definite), aerobic gram-negative bacilli (7 definite and 4 probable), Haemophilus spp. (11 probable), mycoplasma (1 definite and 4 probable), polymicrobial infections (2 definite and 2 probable: E. coli and S. agalactiae, M. tuberculosis and S. aureus, S. pneumoniae and H. influenzae and A. baumannii and K. pneumonias), S. aureus (2 definite and 2 probable) , and mucormycosis (1 definite). Among gram-negative bacilli, K. pneumoniae was the most common agent (8isolates). therates of admission to the intensive care unitand of using assisted ventilation were 18% and 9.3%, respectively. The mortality was 13.8% and logistic regression analysis showed that hypothermia and tachypnea were associated with death. Hospital stay averaged 19 days. Susceptible rates of S. pneumoniae isolated from all body sites to penicillin ranged from 8% to 28% but seven isolated from blood of patients with pneumonia were susceptible to penicillin. Also all 8 isolated of k> pneumoniae from patients with pneumonia were susceptible to cefotaxime and gentamicin. Conclusion: In Korea, in addition to S. pneumoniae, M. tuberculosis is an important agent causing community-acquired pneumonia. The low incidence of etiologic diagnosis is probably related to infrequent requesting of test "atypical" pathogens and does not represent the true incidence of infections by "atypical" pathogens, which well be answered by a prospective study. The antimicrobial resistance rates of major respiratory pathogens from sterile body sites are low, however, because of a small number of the isolates this result needs confirmation by a nationwide surveillance of antimicrobial resistance.

고효율 충전탑에서 MEA 및 AMP 흡수제를 이용한 이산화탄소의 처리

김장호,김형호,강성진,김재홍,이경재 동아대학교 환경문제연구소 2003 硏究報告 Vol.25 No.2

In control technology of green house gas CO₂ exhausted, CO₂ recovery by chemical absorption technology is recommended. In application to a power station and industrial field with using the absorbent MEA and AMP for carbon dioxide removal. we used packing tower(D=0.l5m, H=1.05m) for experimental apparatus on the chemical absorbtion being used extensively as recovery technique of CO₂.