개선된 Brushless DC Motor의 토크리플 최소화

정진화(Jin-hwa Chung),정선태(Sun-Tae Chung) 대한전기학회 1994 대한전기학회 학술대회 논문집 Vol.1994 No.7

2000년 소주 세율 인상의 구명(救命)효과에 대한 실증연구: 국내 자료에 대한 대안적 모형을 중심으로

정진화 ( Jin Hwa Chung ),주하연 ( Ha Yeon Joo ) 한국산업조직학회 2014 産業組織硏究 Vol.22 No.3

본 논문은 2000년 소주 세율이 32%에서 72%로 대폭적으로 인상된 단일 사건이 음주운전 사망률을 비롯한 각종 사망률에 있어서 어떠한 구조적 변화를 발생시켰는지 시군구 지역 단위에서 분석하고자 한다. 특히 미국의 연방 주세가 인상된 단일 시점 전후의 처치효과 (treatment effect)가 지역별 알코올 소비량에 따라 상이함을 입증했던, Cook and Durrance (2013)의 대안적 모형을 도입하여 주세 인상의 구명 효과를 실증적으로 검토한다. 본 논문의 분석 결과에 따르면 주세율의 인상은 손상사망률을 줄이는 효과가 있는 것으로 나타났으며, 그 효과는 특히 자살 부문에서 뚜렷한 것으로 나타났다. 이는 국내 패널자료를 이용하여 지역의 일인당 음주소비량과 사망률(범죄율)사이의 인과관계를 실증적으로 검토한 결과와도 일치한다. This paper investigates a Korean historical event that the national exercise tax on soju was dramatically increased, and estimates how it affects various rates of fatalities. So as to overcome the limited features of Korean liquor tax data with little or no changes across time and regions, we implement the alternative method proposed by Cook and Durrance (2013), which successfully tested heterogeneity in “treatment effects” of alcohol taxes based on a cross-sectional approach. This paper provides the empirical evidence that the percent changes in injury fatality rates are directly related per capita consumption of alcohol in each region. In particular, the estimation results show that an increase in tax rate is strongly related to suicide among all injury fatality. Our findings are consistent with the empirical outcomes by the previous literature using the Korean panel data.

주류소비가 사망률과 범죄율에 미치는 효과분석: 주요 손상사고와 강력범죄를 중심으로

정진화 ( Jin Hwa Chung ),주하연 ( Hailey Hayeon Joo ) 한국응용경제학회 2013 응용경제 Vol.15 No.1

본 논문은 1994-2010년까지의 패널자료를 이용하여 음주남용이 사망률 및 범죄율에 미치는 영향을 실증 분석하였다. 특히 일인당 알코올 소비량과 사망률 및 범죄율 간에 예상되는 내생성 문제를 해소하기 위해 도구변수를 도입하였다. 여러 해외 연구들이 제시한 바와 같이 한국의 경우도 일인당 알코올 소비량과 사망률 및 범죄율 사이에 뚜렷한 양(+)의 인과관계가 식별되었다. 특히 일인당 알코올 소비량의 증가는 자살, 타살, 추락사 등 손상사고에 의한 사망률을 증가 시키며, 살인과 강간 등 강력범죄의 발생을 촉진시키는 효과가 있는 것으로 분 석되었다. 본 논문은 그동안 국내에서 검토되지 않았던 음주소비량과 사망률, 그리고 범죄율 사이의 인과관계를 계량경제학 방법론을 이용하여 분석했다는 점에서 의의를 갖는다. 또한 미국 중심으로 축적되어 있는 실증연구들과 국내의 결과를 비교할 수 있는 기회를 제공한다. This paper investigates how alcohol consumption influences both mortality and crime rates, exploiting the Korean panel data set from 1994 to 2010 in 4 metropolitan areas and 8 regional states. In particular, the instrumental variables are used for both analyses, to solve the potential endogeneity problem in alcohol consumption and mortalities as well as crimes. According to the estimation results, as per-capita alcohol consumption increases, both total mortality and total crime rates increase. Moreover, the increase of per-capita alcohol consumption affects the suicide, homicide, and falling-death rates, while that affects the murder and rape rates. The main contribution of this research is about identifying and confirming that the increase in alcohol consumption can be effective to raise externality costs in Korea.

Freiberg병에서 시행한 Weil 절골술

이화성,권순용,김동욱,정진화,Lee, Hwa-Sung,Kwon, Soon-Yong,Kim, Dong-Wook,Chung, Jin-Wha 대한족부족관절학회 2011 대한족부족관절학회지 Vol.15 No.4

Purpose: The aim of this study was to evaluate the result of combined Weil and dorsal closing wedge osteotomy for Freiberg's disease. Materials and Methods: We performed combined Weil and dorsal closing wedge osteotomy of the second metatarsal under the diagnosis of Freiberg's disease in 7 patients, 7 feet (2 male and 5 female). The mean age at the time of operation was 29 years and the mean follow-up period was 31 months. Patients had no trauma history and no combined deformity of the foot. The surgical results were evaluated by VAS and weight bearing radiographs in antero-posterior and oblique projection. Results: According to Smillie staging system, there were 1 of stage II, 2 of stage III and 4 of stage IV patients. The osteotomy site was united at 8 weeks and the second metatarsal was shortened in length of average 2.8 mm. Remodeling of the metatarsal head was observed at 24 months. The mean VAS was decreased from 8.2 points preoperatively to 2.7 points at follow-up. And average range of motion of second metatarso-phalangeal joint was increased from 30o preoperatively to 45o at follow-up. There was no transfer metatarsalgia or arthritis of the metatarsal head during follow-up. Conclusion: Combined Weil and dorsal closing wedge osteotomy of the metatarsal appears to be an effective procedure for the treatment of Freiberg's disease with a view to shortening of metatarsal length and elevation of metatarsal head.

목포지역 중학생들의 환경교과교육을 실시 효과에 관한 비교 조사연구

박현주 ( Hyun Ju Park ),정진화 ( Jin Hwa Jeong ),정일현 ( Il Hyun Chung ),나춘기 ( Choon Ki Na ) 한국환경과학회 2008 한국환경과학회지 Vol.17 No.4

무지 중수지 관절의 외상성 탈구 치료

이승구,송석환,이화성,정진화,정도현,이원희,Rhee Seung-Koo,Song Seok-Whan,Lee Hwa-Sung,Chung Jin-Wha,Chung Do-Hyun,Lee Won-Hee 대한정형외과스포츠의학회 2002 대한정형외과스포츠의학회지 Vol.1 No.2

목적: 임상적으로드물며, 발생시도수정복이잘안되는무지중수지관절복합탈구의임상적결과를알아보고자하였다.대상및방법: 무지중수지관절의외상성탈구11예(10예후방탈구, 1예전방탈구)를대상으로초기에탈구의정복가능성,도수정복을방해하는해부학적요인, 수술적접근법에관하여조사하였다.결과: 모든증례에서초기에도수정복을시도하였으나, 2예에서만이정복이되었다. 8 례는전방도달법으로관혈정복을하였고, 1예는만성적인소견을보여관절고정술을시행하였다. 정복방해요인은파열된수장판내로근위부에서단무지굴건과요측종자골이감입되어있었고, 중수골두는파열된인대와단무지굴건사이에형성된간격사이로빠져나와있었다.결론: 과신전에의한중수지관절의후방복합탈구는드물지만, 정복이쉽지않아서주로관혈정복이요구되며, 이때정복방해요인인파열된수장판과관절막, 단무지굴건과종자골등에관심을갖고치료에임하여야한다. Purpose: We examined patients to evaluate the clinical results of traumatic metacarpophalangeal(M-P) dislocations of the thumb, uncommon and irreducible. Materials and Methods: In 11 traumatic M-P dislocations of the thumb, the types of dislocations were 10 dorsal and 1 volar dislocations resulted from the impacted and hyperextended forces on thumb. Authors evaluated the possibility of closed reduction, the anatomical structures interfering with closed reduction, and the surgical approaches. Results: Eight cases were treated with open reduction through volar approach and two cases were treated with closed reduction. Joint fusion was done with a plate in a chronic case. Initial closed reduction was attempted in all cases, but succeeded in only 2 cases because the interposed ruptured volar plate, the flexor pollicis brevis tendon and ulnar sesamoid bone at the volar side of the M-Pjoint were the obstacles to reduce. The metacarpal head was caught in button-hole slit between theflexor pollicis brevis and the ruptured volar joint capsule in all cases. Conclusion: Similar with the M-P joint dislocations of other fingers, the dorsal complex M-P dislocations of the thumb due to hyper extension are unusual and can't easily be reduced by closed manipulation. It is necessary to pay attention to the ruptured volar plate, capsule, the subluxated portion ofthe sesamoid and flexor pollicis brevis as interfering structures.

골무기질을 함유한 골시멘트의 강도에 대한 실험적 연구

김용식 ( Yong Sik Kim ),권순용 ( Soon Yong Kwon ),김기원 ( Ki Won Kim ),정진화 ( Jin Hwa Chung ),우영균 ( Young Kyun Woo ) 대한고관절학회 1995 Hip and Pelvis Vol.7 No.2

This study was designed to demonstrate the presence of bone particles at the surface of the bone mineral particle impregnated bone cement, to determine the amount of the bone particle content, if they do exist, and to explore underlying relationships between the contact area of the bone particles and the interfacial shear strength before and after decalcification. For this purpose, specimens with a thickness of 2mm were harvested from canine femur after total hip arthroplasty using bone mineral particles. A confocal laser scanning microscope was used to analyze the surface of the specimen. Push-out test with an MTS machine were performed to determine the interficial shear strength. The following results were obtained: (1) The contact area of the bone particIes at the surface of the bone mineral impregnated bone,cement increased in relation to the weight percent content. (2) The interfacial shear strength of the bone mineral impregnated bone cement was less then that of the bone cement during the period from immediatly after surgery to 12 weeks postoperatively. (3) Temporal increase in interfacial shear strength was not observed in both bone cement and bone mineral impregnated bone cement. In conclusion, this study demonstrated a contradicting fact from the published results in which an increase in interficial shear strength was reported with bone mineral impregnated bone cement. Therefore, we would like to remain cautious to about using the mineral impregnated bone cement until its effectivness is demonstrated.

인체 슬관절 퇴행성 관절염 환자에서 전방십자인대 노화와 관련된 세포자멸사 및 세포증식에 대한 예비조사

현낙민(Rak Min Hyun),김기원(Ki Won Kim),정서원(Seo Won Jeong),정진화(Jin Wha Chung),이화성(Hwa Sung Lee) 대한정형외과학회 2015 대한정형외과학회지 Vol.50 No.4

목적: 고령 환자에서 노화에 의한 슬관절 전방십자인대의 세포자멸사 및 세포증식과의 연관성을 알아보고자 하였다. 대상 및 방법: 퇴행성 관절염으로 슬관절 전치환술을 받은 환자 20명을 대상으로 하였으며, 연령별로 65세 이하는 A군, 66세에서 75세까지는 B군, 76세 이상은 C군으로 분류하였다. 수술 중 채취된 전방십자인대를 이용하여 terminal deoxynucleotidyl transferase dUTP nick-end labeling 방법 및 면역조직화학염색법을 하였고, 세포자멸사 지수 및 세포증식 지수로 정량화하였다. 결과: 모든 실험군에서 세포자멸사가 발현하는 것을 확인하였으며, 세포자멸사 지수는 A군보다 B군에서 높고, B보다 C군이 높았다. 상관분석에서 연령이 1세 증가 시 평균적으로 1.49 증가하였고, 통계적으로 유의한 직선적 양의 관계를 보였다. 세포증식 지수는 A군보다 B군이 낮고, B군보다 C군에서 낮았으며, 연령이 1세 증가 시 평균적으로 1.0 감소하였고, 통계적으로 유의한 직선적 음의 상관관계를 보였다. 세포자멸사 지수와 세포증식 지수는 통계적으로 유의한 음의 상관관계를 보였으며, 세포자멸사 지수가 1.0 증가 시 세포증식 지수는 0.45 감소하였다. 결론: 슬관절 전방십자인대에서 세포자멸사를 확인할 수 있었으며, 연령이 증가함에 따라 세포자멸사가 증가되고, 세포증식은 감소하였다. Purpose: We investigated the association between aging-induced apoptosis and cell proliferation in the anterior cruciate ligament (ACL) of aged patients. Materials and Methods: Twenty patients with osteoarthritis who underwent total knee replacement arthroplasty were enrolled in the study. They were divided into three groups according to age: group A (≤65 years), group B (66-75 years), and group C (≥76 years). The ACL tissue was obtained intraoperatively and subjected to terminal deoxynucleotidyl transferase dUTP nick-end labeling staining and immunohistochemistry to quantify the apoptosis and cell proliferation indices. Results: Apoptosis occurred in all groups, with the highest apoptosis index found in group C, followed by that in groups B and A. A statistically significant positive linear correlation was observed, with a 1-year increase in age resulting in an average increase of 1.49 in the apoptotic index. The lowest cell proliferation index was observed in group C, followed by that in group B and group A, with a 1-year increase in age resulting in an average decrease of 1.0 in the cell proliferation index, which was a statistically significant negative linear correlation. Consequently, a statistically significant negative correlation was confirmed between the apoptosis and cell proliferation indices, whereby an increase of 1.0 in the apoptosis index was concurrent with a decrease of 0.45 in the cell proliferation index. Conclusion: Apoptosis occurred in the ACL of human knee joint. With increasing age, apoptosis increased and cell proliferation decreased.

정상형 및 원판형 외측 반월상 연골의 파열 양상

김정만(Jung Man Kim),한창환(Chang Hwan Han),연건(Gun Yeon),정진화(Jin Hwa Chung) 대한정형외과학회 1997 대한정형외과학회지 Vol.32 No.3

750kW gearless 풍력발전기 인버터 시험

손윤규(Son, Yoon-Gyu),서재학(Suh, Jae-Hak),권세진(Kwon, Sei-Jin),장성덕(Jang, Seung-Duck),오종석(Oh, Jong-Seok),황진수(Hwang, Jin-Su),강신일(Kang, Sin-Il),박가우(Park, Ga-Woo),권오정(Kwon, O-Jung),정진화(Chung, Chin-Hwa),한경섭(Han, 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

The 800-kW PM (permanent magnet) synchronous generator is developed as a wind power generator. The matching converter is designed to control the torque and power depending on the wind speed regime. The generator starts to generate the power at the speed of 9 rpm and the rated output is generated at the speed of 25 rpm. The rated output power of an inverter is 750 kW when the PM synchronous generator is delivering 800 kW to the inverter. The inverter is specially designed to perform the maximum power point tracking (MPPT) at the low wind speed regime that is typical wind environment in Korea. The inverter test was done with a 2 MW M-G system at KERI (Korea Electric Research Institute). The M-G set has a 2 MW motor driver and a 38:1 gear to match the speed between the motor and the PM generator. The torque simulating the wind is applied to the PM generator by a DC motor. The test results show the inverter efficiency of 94.3% at the rated power generating condition. The measured values show that the MPPT algorithm is working well. Overall reliability will be verified through the long-term site test.