One-Chip uP에 의한 CO₂가스메탈 아크용접기의 디지털 제어기 설계에 관한 연구

최규하,채영민,송성학,우동학,한광수,안기은 건국대학교 1997 學術誌 Vol.41 No.2

With the development of semiconductor devices, adaptation of microcontroller prevails in industrial area. But in arc welding industry, there has not been much progress in adoption microcontroller technology. Therefore, this paper shows the application of digital control technology to welding machine. This paper presents the design of microcontroller that is appropriate for three phase CO2 gas metal arc welding machine. By using microcontroller in CO2 gas metal arc welding machine, the overact cost can be reduced compared to analog type one. Also TMS370C850 microprocessor is used as overall microcontroller for the arc welding machine.

스포츠 유형과 신체적 자기개념과의 관계 연구

김상규,박은하 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.4

The purpose of this study was to examine the relationship of the type of sports to physical self-description. The subjects were 242 secondary school students from Gangweon province, who were engaged in 12 different types of sports including individual sports, individual contact sports, noncontact group sports, group contact sports, and noncontact sports. After a survey was conducted with Kim Byeong-jun(2001)'s Korean version of physical self-description inventory, the collected data were analyzed with SPSS program To look for connections between the types of sports and physical self-description, statistical data on mean and standard deviation were obtained, and then t-test was implemented. And one-way ANOVA was implemented to identify the influence of their gender, school grade and workout period. The findings of this study were as follows: 1. Among the individual sport players, the contact sport players had a better physical self-description than the noncontact sport players, but the difference between the two groups was insignificant, 2. In the field of the group sports, there was little gap in physical self-description between the contact sport players and noncontact sport players. 3. Regarding the effect of the individual and group sports on physical self-description, there was little gap between the individual and group sport players.

사업장 근로자의 건강위험 평가도구 개발

정규철,이용애,홍윤철,조희숙,박혜숙,임현술,하은희 이화여자대학교 환경문제연구소 1998 이화환경연구 Vol.2 No.-

Health Risk Appraisal(HRA) is usually defined as a process by which we expect of individual's chances of acquiring specific diseases within a defined period of time. The concept of worksite as an area of health maintenance and promotion is newly developing. Our movement for health promotion of employees has been increasingly known in the worksite. The aim of this study is to develop health risk appraisal tools about health promotion at the worksite for employees. We performed this study by two steps: one step was to develop a HRA questionnaire of worksites in Korea, another was to evaluate the reliability of the questionnaire. For developing HRA questionnaire, we reviewed scientific examples at first, and then weighted the score by delphi. To evaluate the reliability of developed questionnaire, we carried out survey by test-retest method. A total of 131 employees completed HRA questionnaire on two times. The results are as follows. The total score of health risk in unhealthy workers was higher than that of healthy workers. The range of test-retest reliability of responses to the questionnaire was 0.57-0.94. Therefore it seems that this questionnaire was very suitable to assess the health behavior of workers. In conclusion, the developed HRA questionnaire can be used as a tool for evaluating health behavior and for providing health counseling materials.

사업장 근로자의 건강위험 평가도구 개발

홍윤철,임현술,하은희,정규철,조희숙,박혜숙,이용애 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.4

Health Risk Appraisal(HRA) is usually defined as a process by which we expect of individual's chances of death or acquiring specific diseases within a defined period of time. The concept of worksite as an area of health maintenance and promotion is newly developing. Our movement for health promotion of employees has been increasingly known in the worksite. The aim of this study is to develop health risk appraisal tools about health promotion at the worksite for employees. We performed this study by two steps; one step was to develop a HRA questionnaire of worksites in Korea, another was to evaluate the reliability of the questionnaire. For developing HRA questionnaire, we reviewed scientific examples at first, and then weighted the score by delphi. To evaluate the reliability of developed questionnaire, we carried out survey by test-retest method. A total of 131 employees completed HRA questionnaire on two times. The results are as follows. The total score of health risk in unhealthy workers was higher than that of healthy workers. The range of test-retest reliability of responses to the questionnaire was 0.57-0.94. Therefore it seems that this questionnaire was very suitable to assess the health behavior of workers. In conclusion, the developed HRA questionnaire can be used as a tool for evaluating health behavior and for providing health counseling materials.

흉요추 이행부 골절환자의 임상분석

김준수,김은상,이종서,박용규,백선하,박인성,정진명,한종우 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.10

To clarify the prognostic factors influencing clinical outcome. the authors retrospectively analyzed 50 cases of thoracolumbar vertebral junctuon fracture treated at our hospital between September 1989 and October 1992. The age of the patients ranged from 23 to 75years(median 49years) and the male-to-female ratio was 33:17. Falling was the major mode of injury(n=27). The kyphotic angle between fractured vertebrae and the ratio of neural canal encroachment was measured in a simple X-ray and a computed tomography(CT) of the thoracic spine. An ANOVA test was performed to evaulate the predicting factors to determine the final outcome. The kyphotic angle and loss of height of vertebral body were not significantly correalted with the neurological status of the patients. However. the ratio of the compromised area of the neural canal was closely correlated with the neurological outcome(p value<0.05). The worst prognosis was found in patients with fracture-dislocation. In conclusion. it is suggested that early surgical intervention must be considered in the neurologically compromised patients whose CT demonstrates neural canal encroachment by bony fragments.

뇌동맥류 파열에 의한 급성 경막하 혈종이나 뇌내혈종을 동반한 혼수상태 환자에 대한 뇌혈관 조영술을 시행하지 않은 응급수술

황수현,박용규,백선하,박인성,김은상,정진명,한종우 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.10

Neurologically based clinical grading scales offer excellent prognostic information for the patient suuffering diffuse subarachnoid hemorrhaging. These grading scales are less applicable to patients with life-threatening intraparenchymal or subdural hematomas after aneurysmal rupture. During 2 and half years. 9 patients(ICH;5.SDH:1. ICH+SDH:3) in a comatose state with brain stem compression syndromes documented by computerized tomographic scans have undergone emergent operation without angiography in our neurosurgical departement. Each patient was so critically ill that we believed it unwise to delay craniotomy for diagnostic angiography. The average delay from the detection to operation was 2 hours. The origin of the hematoma was identified as a berry aneurysm of the middle cerebral artery bifurcation in seven patients and a posterior communicating artery aneurysm in two patients. One patient had a good recovery. two patients recovered with hemipardsis and mild cognitive dysfunction. two patients were vegetative and died due to pneumonia. and four patients died due to brain swelling within two weeks postoperatively. Emergent craniotomy with empiric exploration of appropriate subarachnoid cisterns after hematoma decompression may be life-saving management in some cases. The delay imposed for diagnostic angiography may be avoided in attempts to save vital minutes of severe brain stem compression.

Clinical Characteristics of Smoking Asthmatics

( Eun Sil Ha ),( Hye Ok Kim ),( Kyoung Ju Lee ),( Eun Joo Lee ),( Gyu Young Hur ),( Ki Hwan Jung ),( Sung Yong Lee ),( Je Hyeong Kim ),( Sang Yeub Lee ),( Chol Shin ),( Jae Jeong Shim ),( Kyung Ho Kan 대한결핵 및 호흡기학회 2009 Tuberculosis and Respiratory Diseases Vol.67 No.6

Background: The smoking prevalence in asthma patients are similar to those in the general population. Asthma and active cigarette smoking can interact to create more severe symptoms, an accelerated decline in lung function and impaired therapeutic responses. Accordingly, asthmatics with a history of smoking were examined to define the clinical characteristics and lung function of smoking asthmatics. Methods: The medical records of 142 asthmatics with a known smoking history were reviewed. The patients were divided into three groups according to their smoking history-current smokers, former smokers and non-smokers. The clinical characteristics, lung function, and annual declines of the forced expiratory volume in one second (FEV1) were compared. Results: Fifty-three of the 142 patients (37%) were current smokers, 24 were former smokers (17%) and 65 were non-smokers (45%). The patients with a hospital admission history during the previous year included 16 current smokers (30%), 4 former smokers (17%) and 7 non-smokers (11%) (p=0.02). The mean FEV1 (% predicted) was 76.8±19.8%, 71.6±21.1% and 87.9±18.7% for current smokers, former smokers and non-smokers, respectively (p<0.001). The FEV1/forced vital capacity (FVC) (ratio, %) values were 63.6±12.6%, 59.3±14.9% and 72.1±11.8% in current smokers, former smokers and non-smokers, respectively (p<0.001). The corresponding mean values for the individual FEV1 slopes were not significant (p=0.33). Conclusion: Asthmatic smokers demonstrated higher hospital admission rates and lower lung function. These findings suggest that the smoking history is an important predictor of a poor clinical outcome in asthma patients.

Structure and Properties of Thermotropic Polyarylate/Polycarbonate Blends Compatibilized by Catalyst-assisted Ester-Carbonate Interchange Reactions

Ha-Eun Gang,Yunju Chang,최은지,So-Jeong Lee,Gyu-Tae Park,전하빈,Soo Yeon Kim,Young Gyu Jeong 한국섬유공학회 2022 Fibers and polymers Vol.23 No.7

We herein report the morphology, rheological, thermal, and dynamic mechanical properties of thermotropicpolyarylate/polycarbonate (PAR/PC, 70/30 by wt%) blends, which are compatibilized via melt-processing in the presence ofdifferent tetrabutylammonium tetraphenylborate catalyst loadings of 0.0-1.0 phr. The electron microscopic images exhibit thatthe compatibility of PAR/PC blends is improved with increasing the catalyst loading at the melt-compounding. The infraredspectroscopic analysis reveals the formation of PAR-co-PC copolymers in the melt-compounded blends via catalyst-assistedinterchange reactions between ester groups of PAR and carbonate groups of PC. Accordingly, the shear moduli and complexviscosity at a melt state increase for the melt-processed blends with higher catalyst loadings. In addition, the meltcrystallizationand melting temperatures of PAR and the glass transition temperature of PC tend to decrease for the blendsmanufactured at higher catalyst contents due to the shortening of crystallizable PAR and amorphous PC segments. Interestingly, the residue at 800 °C increases for the melt-processed blends with higher catalyst loadings. The elastic storagemoduli of compatibilized PAR/PCT blends at a glassy sate are almost the same as that of neat PAR and far higher than that ofneat PC. It is thus believed that PAR/PC blends can be efficiently compatibilized via catalyst-assisted ester-carbonateinterchange reactions through a facile and scalable melt-compounding process and they can be used as engineering polymericmaterials that alleviate the disadvantages of thermotropic PAR caused by its high anisotropic structure and physical properties.

Clinical Characteristics of Smoking Asthmatics

Ha, Eun Sil,Kim, Hye Ok,Lee, Kyoung Ju,Lee, Eun Joo,Hur, Gyu Young,Jung, Ki Hwan,Lee, Sung Yong,Kim, Je Hyeong,Lee, Sang Yeub,Shin, Chol,Shim, Jae Jeong,Kang, Kyung Ho,Yoo, Se Hwa,In, Kwang Ho The Korean Academy of Tuberculosis and Respiratory 2009 Tuberculosis and Respiratory Diseases Vol.67 No.6

Background: The smoking prevalence in asthma patients are similar to those in the general population. Asthma and active cigarette smoking can interact to create more severe symptoms, an accelerated decline in lung function and impaired therapeutic responses. Accordingly, asthmatics with a history of smoking were examined to define the clinical characteristics and lung function of smoking asthmatics. Methods: The medical records of 142 asthmatics with a known smoking history were reviewed. The patients were divided into three groups according to their smoking history - current smokers, former smokers and non-smokers. The clinical characteristics, lung function, and annual declines of the forced expiratory volume in one second ($FEV_1$) were compared. Results: Fifty-three of the 142 patients (37%) were current smokers, 24 were former smokers (17%) and 65 were non-smokers (45%). The patients with a hospital admission history during the previous year included 16 current smokers (30%), 4 former smokers (17%) and 7 non-smokers (11%) (p=0.02). The mean $FEV_1$ (% predicted) was 76.8${\pm}$19.8%, 71.6${\pm}$21.1% and 87.9${\pm}$18.7% for current smokers, former smokers and non-smokers, respectively (p< 0.001). The $FEV_1$/forced vital capacity (FVC) (ratio, %) values were 63.6${\pm}$12.6%, 59.3${\pm}$14.9% and 72.1${\pm}$11.8% in current smokers, former smokers and non-smokers, respectively (p<0.001). The corresponding mean values for the individual $FEV_1$ slopes were not significant (p=0.33). Conclusion: Asthmatic smokers demonstrated higher hospital admission rates and lower lung function. These findings suggest that the smoking history is an important predictor of a poor clinical outcome in asthma patients.

Usefulness of 2D shear wave elastography for the evaluation of hepatic fibrosis and treatment response in patients with autoimmune hepatitis

Soh Eun Gyu,이영환,Kim Youe Ree,Yoon Kwon-Ha,Choi Keum Ha 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.4

Purpose: The purpose of this study was to determine the usefulness of two-dimensional shear wave elastography (2D SWE) in the assessment of liver stiffness (LS) and dispersion slope (DS) to evaluate hepatic fibrosis and the treatment response in patients with autoimmune hepatitis (AIH). Methods: Patients diagnosed with AIH who underwent 2D SWE between June 2014 and June 2021 were enrolled in this retrospective study. The patients were classified into four groups according to the histologic stage of fibrosis (F1-F4). The baseline characteristics, laboratory test results, histologic results, and 2D SWE results were analyzed. The diagnostic performance of LS measurements in hepatic fibrosis staging was investigated, and variables were compared before and after steroid treatment for AIH. Results: In total, 69 patients were analyzed. The LS values differed according to the stage of liver fibrosis (P<0.001). The area under the curve for LS was 0.903, 0.815, and 0.854 for ≥F2, ≥F3, and F4, respectively. The diagnostic performance of LS measurements was significantly greater than that of serum biomarkers, except for fibrosis index-4 for F4 (P<0.05). Significant differences were observed in follow-up examinations in both the LS value and DS in patients who received steroid therapy (P=0.012 and P=0.011, respectively). Conclusion: In conclusion, 2D SWE is a useful method for the assessment of hepatic fibrosis in patients with AIH. In follow-up examinations, LS and DS can be used as reliable parameters to evaluate the treatment response of AIH.