Hepatic Cirrhosis Occurring in a Young Woodchuck(Marmota monax) Due to Vertical Transmission of Woodchuck Hepatitis Virus(WHV)

Kyu-shik Jeong,정원일,Jae-yong Chung,Mi-young An,Chae-yong Jung,Gyoung-jae Lee,Jong-soo Kang,Byeong-cheol Kang,Young-heun Jee,Bruce H Williams,Young-oh Kwon,Da-hee Jeong 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.2

Cirrhosis Occurring in a Young Woodchuck (Marmota monax) Due to Vertical Transmission of Woodchuck Hepatitis Virus (WHV)Da-hee Jeong, Won-il Jeong, Jae-yong Chung, Mi-young An, Chae-yong Jung, Gyoung-jae Lee1, Jong-soo Kang1, Byeong-cheol Kang2, Young-heun Jee3, Bruce H Williams4, Young-oh Kwon5 and Kyu-shik Jeong*College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Korea1Shinwon Scientific Co., LTD, Research Institute, Suwon, Korea2Clinical Research Institute, Seoul National University, Seoul 110-744, Korea3College of Veterinary Medicine, Jeju National University, Jeju 690-756, Korea

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.

전도 EMI 필터 부품의 새로운 모델링 회로

정용채 남서울대학교 2004 남서울대학교 논문집 Vol.10 No.-

Plenty of electromagnetic interference (EMI) noise is generated in a high frequency power conversion circuit. The EMI noise can be divided into a conducted component and a radiated one. In general, it takes a little longer time to reduce the conducted EMI noise in a power converter. After the suppression methods for a noise source and a path are sufficiently executed, the residual noise can be attenuated by EMI filters. Mostly, it takes many times to design the EMI filters owing to utilizing the trial and error method. There are common-mode (CM) and differential-mode (DM) components in the conducted EMI, and the suppression filters against each mode are different. Thus, these two filters should be separately designed, and composed. Therefore, high frequency models of components are proposed to simplify the filter design in this paper. Using the modeling circuit, the filter design can be carried out applicable to each mode. Finally, the validity of the proposed models is verified through the measurement results.

대용량 인버터 에어컨용 병렬구조의 역률제어회로

정용채 남서울대학교 공학연구센터 1999 공학연구 Vol.1 No.-

In this paper, the power factor correction circuit using a parallel drive method is proposed so that the high power inverter air-conditioner with 3[hp] compressor motor may down the cost and improve performance. The adequate design procedures are presented to reduce the material cost by eliminating the power factor improving LC filter and derating output capacitor and inverter switches. Using the determined components, the proto-type circuit with 6[kW] power consumption is built and tested to verify the operation of the proposed circuit.

주파수 변조기법을 이용한 전자레인지용 직렬 공진형 하프 브릿지 인버터

정용채 남서울대학교 2002 남서울대학교 논문집 Vol.8 No.-

In this paper, the inverter circuits applied to high-quality microwave oven are investigated and compared with each another. Then a suitable circuit is selected for United States of America market which use 120V utility line. Operation and characteristic for each circuit are explained in brief. If the choosing circuit is controlled by fixing frequency PWM method, the operating rate of magnetron (MGT) is reduced. Thus, the output power of MGT cannot be raised because the current of MGT is limited to any level. Therefore, a frequency modulation technique is proposed cope with this problem. Since the operating rate of MGT can be improved using the frequency modulation technique, the output power can be enhanced to a higher level. To verify the abovementioned point, inverter circuit with 120V 2kW input consumption is manufactured and tested. Throughout the experimental results, an improvement of the operating rate of MGT can be confirmed.

발열을 동반한 호중구감소증에서 Cefepime 단독투여와 Ceftazidime 및 Tobramycin 병합투여의 효능비교

정현욱,채제욱,강미라,양정채,문치숙,기현균,장현하,오원섭,김기현,백경란,이남용,송재훈 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내에서 발열을 동반한 호중구감소증이 있는 악성 종양환자에게 경험적 항생제로 베타락탐계 항생제와 아미노배당체의 병합요법의 사용이 일반적이다. Cefepime은 광범위 항균 작용을 가지고 있어, 그람 음성균 뿐만 아니라 그람 양성균에 대해서도 우수한 효과를 나타낸다. 재료 및 방법: 발열을 동반한 호중구감소증이 있는 악성 종양환자를 대상으로 무작위, 공개, 비교 연구를 시행하였다. 대상 환자를 무작위로 cefepime 단독요법군과 ceftazidime 및 tobramycin 병합요법군으로 나누어 투여하고 각각의 임상적 효능과 안전성을 비교하였다. 구강및 인후 점막염이 있는 환자에서 분리된 녹색 연쇄알 구균에 대한 항생제 내성 정도를 조사하였다. 결과 : 대상환자 89명 중 CA 투여군이 48예(53.9%), CT 투여군이 41예(46.1%)이었다. 발열의 유형별로 MDI는 18예(20.2%), CDI는 9예(10.1%), UF는 62예(69.7%)로 두 군 간에 차이가 없었다. CA 투여군과 CT 투여군의 임상적 호전률은 시험약 투여 후 2-4일째 각각 91.7%, 85.4% (P=0.31), 치료 종료 시 각각 91.7%, 100% (P=0.15)로 두 군간에 유의한 차이가 없었다. 치료 종료 시 CA 투여군과 CT 투여군의 세균학적 소실률은 모두 100%로 두 군간의 유의한 차이가 없었다(P=0.78). 점막염이 있는 환자로부터 녹색 연쇄알 구균이 분리된 경우는 25예(28.1%)이었으며, 분리된 녹색 연쇄알 구균은 penicillin, ceftriaxone, cefepime, vancomycin에 모두 감수성을 보였다. 약제 관련 이상 반응의 발생 빈도도 두 군간에 유의한 차이가 없었다. 결론 : 발열을 동반한 호중구감소증이 있는 악성 종양환자의 경험적 항생제로서 cefepime 단독요법은 ceftazidime 및 아미노배당체의 병합요법만큼 효과적이고 안전하였다. Background : Broad-spectrum antibiotic therapy has been recommended as an empirical regimen in cancer patients with febrile neutropenia. Cefepime is a fourth generation cephalosporin with good activity against both gram-positive cocci and gram-negative bacilli. Materials and Methods : To compare the efficacy and safety of cefepime alone with ceftazidime plus tobramycin as empirical regimen for adult cancer patients with febrile neutropenia, a randomized, open label, comparative trial was performed. If the patient showed clinical improvent 72 hours, antibiotic could be changed to oral ciprofloxacin. Clinical and microbiological responses were determined at 72 hours and at the end of therapy. To investigate the antimicrobial resistance of viridans streptococci, swab cultures were obtained from throat in all enrolled patients and antimicrobial susceptibility tests were performed by using microdilution method according to the NCCLS. Results : A total of 89 patients were enrolled. Forty-eight patients received cefepime alone (CA), and 41 patients received ceftazidime plus tobramycin (CT). Demographic and baseline clinical characteristics were similar in both groups (P>0.05). The initial clinical success rate at day 2-4 in group CA (91.7%) was similar with that in CT group (85.4%) (P=0.31). At the end of therapy, the final clinical success rate in CA group (91.7%) was similar to that in CT group (100%) (P=0.15). In 18 patients, with microbiologically defined infections, the eradication rate was 100% in both groups. Adverse events including liver dysfunction (21.3%) and renal dysfunction (2.2%), were similar in both groups (P=0.87). Viridans streptococci were isolated from the throat cultures in 25 cases, and all of these strains were susceptible to penicillin (MIC_(90) 0.12 ㎍/mL), cefepime (1 ㎍/mL), and vancomycin (0.12 ㎍/mL). Conclusion : Efficacy and safety of cefepime monotherapy was comparable to the combination of ceftazidime and tobramycin. It could be used as an alternative empirical regimen for treating cancer patients with febrile neutropenia.

PLS용 세미브리지 인버터의 효율분석에 관한 연구

정용채 남서울대학교 2005 남서울대학교 논문집 Vol.11 No.2

The aim of the paper is to analyze the losses of the PLS(Plasma Lighting System) driving inverter circuit. The conventional driving method of the PLS is to utilize a high voltage transformer(HVT). In this case, the overall system is bulky and has low efficiency. Therefore, to overcome these problems, the Semi-Bridge inverter circuit with power factor correction is used. Through the loss analysis for the inverter circuit, the optimal inverter circuit is designed. To verify the abovementioned point, inverter circuit with 220V 400W input consumption is manufactured and tested. Throughout the experimental results, the high efficiency PLS system without flicker has confirmed.

공기청정기를 위한 음이온 및 클러스터 발생회로

정용채 남서울대학교 공학연구센터 2003 공학연구 Vol.4 No.-

In this paper, new negative ion and cluster generating circuit is proposed for the air cleaner. The circuit has two modes, cluster mode and negative ion mode. Each mode can be changed by using a simple relay. In the cluster mode, the same quantities of negative and positive ions are produced. However, in the negative ion mode, the negative ion is only generated. Operating principles of the proposed circuit are explained in detail. To verify the abovementioned point, the proto type generating circuit is manufactured and tested. Throughout the experimental results, the performance of each mode can be confirmed.

역률제어회로를 갖는 무전극 황전등 구동용 인버터 회로

정용채 남서울대학교 2003 남서울대학교 논문집 Vol.9 No.-

The electrodeless sulfur lamp is the one of the very high frequency discharge lamp. The sulfur molecules in the lamp are. activated by 2.45GHz microwave. This state is called by the plasma one. So, the such system is named as Plasma Lighting System(PLS). The conventional driving method of the PLS is to utilize a high voltage transformer(HVT). In this case, the overall system is bulky and has low efficiency. Therefore, to overcome these problems, the invertw circuit with power factor correction is proposed for driving the plasma lighting system in this paper. To verify the abovementioned point, inverter circuit with 220V 300W input consumption is manufactured and tested. Throughout the experimental results, the compact system without flicker can be confirmed.

Smart Power IC를 이용한 스위칭 모드 전원회로의 설계에 관한 연구

정용채 남서울대학교 2005 남서울대학교 논문집 Vol.11 No.1

In this paper, the switching mode power supply (SMPS) design procedure using a Smart Power IC is presented. Using a design example, the design procedure is described in detail. In particular, I concentrate my efforts on the transformer design. In addition, RCD snubber and output capacitor are also designed.